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Sample records for kilns employing particle

  1. Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion.

    PubMed

    Konopa, Stephanie Lucero; Mulholland, James A; Realff, Matthew J; Lemieux, Paul M

    2008-08-01

    The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO2), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particle-board combustion, consistent with its higher nitrogen content. SO2 emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet.

  2. Emissions from carpet combustion in a pilot-scale rotary kiln: comparison with coal and particle-board combustion

    SciTech Connect

    Stephanie Lucero Konopa; James A. Mulholland; Matthew J. Realff; Paul M. Lemieux

    2008-08-15

    The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO{sub 2}), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particleboard combustion, consistent with its higher nitrogen content. S{sub 2} emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet. 13 refs., 5 figs., 1 tab.

  3. Rotary kiln seal

    SciTech Connect

    Drexler, Robert L.

    1992-01-01

    A rotary seal used to prevent the escape of contaminates from a rotating kiln incinerator. The rotating seal combines a rotating disc plate which is attached to the rotating kiln shell and four sets of non-rotating carbon seal bars housed in a primary and secondary housing and which rub on the sides of the disc. A seal air system is used to create a positive pressure in a chamber between the primary and secondary seals to create a positive air flow into the contaminated gas chamber. The seal air system also employs an air inlet located between the secondary and tertiary seals to further insure that no contaminates pass the seal and enter the external environment and to provide makeup air for the air which flows into the contaminated gas chamber. The pressure exerted by the seal bars on the rotating disc is controlled by means of a preload spring. The seal is capable of operating in a thermally changing environment where the both radial expansion and axial movement of the rotating kiln do not result in the failure of the seal.

  4. Particle accelerator employing transient space charge potentials

    DOEpatents

    Post, Richard F.

    1990-01-01

    The invention provides an accelerator for ions and charged particles. The plasma is generated and confined in a magnetic mirror field. The electrons of the plasma are heated to high temperatures. A series of local coils are placed along the axis of the magnetic mirror field. As an ion or particle beam is directed along the axis in sequence the coils are rapidly pulsed creating a space charge to accelerate and focus the beam of ions or charged particles.

  5. Physico-chemical and optical properties of combustion-generated particles from coal-fired power plant, automobile and ship engine and charcoal kiln.

    NASA Astrophysics Data System (ADS)

    Kim, Hwajin

    2015-04-01

    Similarities and differences in physico-chemical and optical properties of combustion generated particles from various sources were investigated. Coal-fired power plant, charcoal kiln, automobile and ship engine were major sources, representing combustions of coal, biomass and two different types of diesel, respectively. Scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM) and energy-dispersive X-ray spectroscopy (EDX) equipped with both SEM and HRTEM were used for physico-chemical analysis. Light absorbing properties were assessed using a spectrometer equipped with an integrating sphere. Particles generated from different combustion sources and conditions demonstrate great variability in their morphology, structure and composition. From coal-fired power plant, both fly ash and flue gas were mostly composed of heterogeneously mixed mineral ash spheres, suggesting that the complete combustion was occurred releasing carbonaceous species out at high temperature (1200-1300 °C). Both automobile and ship exhausts from diesel combustions show typical features of soot: concentric circles comprised of closely-packed graphene layers. However, heavy fuel oil (HFO) combusted particles from ship exhaust demonstrate more complex compositions containing different morphology of particles other than soot, e.g., spherical shape of char particles composed of minerals and carbon. Even for the soot aggregates, particles from HFO burning have different chemical compositions; carbon is dominated but Ca (29.8%), S (28.7%), Na(1%), and Mg(1%) are contained, respectively which were not found from particles of automobile emission. This indicates that chemical compositions and burning conditions are significant to determine the fate of particles. Finally, from biomass burning, amorphous and droplet-like carbonaceous particles with no crystallite structure are observed and they are generally formed by the condensation of low volatile species at low

  6. LIME KILN BUILDING, KILN BOTTOM SHOWING ROTATOR GEAR. (GEAR IS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    LIME KILN BUILDING, KILN BOTTOM SHOWING ROTATOR GEAR. (GEAR IS POINTED DOWN FOR PROPER ORIENTATION). - Solvay Process Company, Lime Kiln Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  7. Packaged kiln dried firewood

    SciTech Connect

    Cutrara, A.

    1986-07-01

    A process is described for kiln drying firewood consisting of essentially uniform lengths of split firewood pieces, the process comprising splitting essentially uniform lengths of green tree logs to form firewood pieces, placing the firewood pieces in open mesh bags to provide a plurality of bags of firewood, placing the plurality of bags of green firewood pieces in a kiln drying oven, kiln drying the pieces at temperatures in excess of 150/sup 0/F. by moving heated air over the pieces until the pieces have an overall moisture content ranging from 15% up to 30% by weight, operating the kiln at a temperature below a level which would render the structural characteristics of the bag useless and removing the kiln dried firewood pieces in the plurality of bags from the kiln drying oven.

  8. Solar heated rotary kiln

    SciTech Connect

    Shell, Pamela K.

    1984-01-01

    A solar heated rotary kiln utilized for decomposition of materials, such as zinc sulfate. The rotary kiln has an open end and is enclosed in a sealed container having a window positioned for directing solar energy into the open end of the kiln. The material to be decomposed is directed through the container into the kiln by a feed tube. The container is also provided with an outlet for exhaust gases and an outlet for spent solids, and rests on a tiltable base. The window may be cooled and kept clear of debris by coolant gases.

  9. Solar heated rotary kiln

    SciTech Connect

    Shell, P.K.

    1984-04-17

    A solar heated rotary kiln utilized for decomposition of materials, such as zinc sulfate. The rotary kiln has an open end and is enclosed in a sealed container having a window positioned for directing solar energy into the open end of the kiln. The material to be decomposed is directed through the container into the kiln by a feed tube. The container is also provided with an outlet for exhaust gases and an outlet for spent solids, and rests on a tiltable base. The window may be cooled and kept clear of debris by coolant gases.

  10. System for recycling char in iron oxide reducing kilns

    SciTech Connect

    Baker, A.C.; Keran, V.P.

    1983-03-08

    A method and means for improving the efficiency of the process for directly reducing ore containing iron oxide in a rotary kiln using a solid carbonaceous reducing agent, such as coal, introduced from the ore feed and discharge ends of the kiln, as both fuel and reductant, is disclosed wherein the charred coal or char found in the discharge product is recycled into the process at the discharge end of the kiln rather than the feed end as in the prior art. In particular, the recovered char, both coarse and finer particles, are transported to a recycle bin from which they are returned at a preselected rate to the kiln process by being injected along with the coal blown into the discharge end of the kiln. Alternatively, the recycle char alone may be fed without any coal at the discharge end of the kiln.

  11. Analysis of the elemental composition of Tang Sancai from the four major kilns in China using EDXRF

    NASA Astrophysics Data System (ADS)

    Ma, Bo; Liu, Long; Feng, Song-Lin; Xu, Qing; Feng, Xiang-Qian

    2014-01-01

    Tang Sancai was widely used in the Tang Dynasty, and the study of this pottery provides information about the sociocultural aspects of the Tang people. To understand the characteristics of the different kilns for the production of Tang Sancai, Energy Dispersive X-ray Fluorescence (EDXRF) was used to analyze 174 Tang Sancai shards. These specimens were selected from four production centers in the Tang Dynasty, namely, the Huangye Kiln, the Huangbu Kiln, the Xing Kiln and the Liquanfang Kiln. The results demonstrate that the clay bodies from different kilns have varying compositions, and each kiln has a unique elemental fingerprint. Of the 17 elements analyzed, TiO2 and Fe2O3 had distinctly different contents in the samples from the Huangye Kiln and the Huangbu Kiln. For the Xing Kiln and the Huangye Kiln, the characteristic elements are Fe2O3 and MnO. For the Xing Kiln and the Huangbu Kiln, the most dissimilar elements are TiO2, MnO and ZnO. When the Principal Component Analysis (PCA) was employed, the data points for the Huangye Kiln, the Huangbu Kiln and the Xing Kiln fell into distinct areas. For the Liquanfang Kiln, the contents of Al2O3 and Fe2O3 in white-bodied samples are different from those of other colors, which indicates that at least two types of raw materials were used. When compared with the white-bodied samples from the other three kilns, the white-bodied samples from the Liquanfang Kiln were found to have compositions similar to those of the samples from the Huangye Kiln, rather than the Huangbu Kiln, although the latter is much closer geographically than the former. All the obtained data provide valuable scientific criteria for provenance identification for Tang Sancai of unknown origin.

  12. Evaluating tunnel kiln performance

    SciTech Connect

    O`Connor, K.R.; Carty, W.M.; Ninos, N.J.

    1997-08-01

    Process improvements in the production of whitewares provide the potential for substantial savings for manufacturers. A typical whiteware manufacturer incurs an annual defective product loss of {approximately}$20 million when accounting for raw materials, energy, labor and waste disposal. Reduction in defective product loss of 1% could result in a savings in excess of $1 million annually. This study was designed to establish benchmarks for two conventional tunnel kilns used to bisque-fire dinnerware at Buffalo China Inc. (Buffalo, NY). The benchmark was established by assessing the current conditions and variability of the two tunnel kilns as a function of the fracture strength of sample bars that were made from production body. Sample bars were fired in multiple locations in both kilns to assess the conditions and variability of firing within each kiln. Comparison of strength results between the two kilns also was assessed. These comparisons were accomplished through applied statistical analysis, wherein significant statistical variations were identified and isolated for both tunnel kilns. The statistical methods and tools used in this analysis are readily accessible to manufacturers, thus allowing implementation of similar analysis, or benchmarking, in-house.

  13. Bi-flow rotary kiln coal gasification process

    SciTech Connect

    Garside, P.G.

    1983-02-22

    A process is disclosed for gasifying solid coal particles in a rotary kiln that produces simultaneously and continuously two distinctly different fuel gas streams from the opposite ends of a single kiln. A relatively low temperature gas is discharged from the solids inlet end of the kiln, which contains substantially all tars produced by the process. A second of the gas streams is discharged from the solids discharge end of the kiln at approximately 1,900* F. And substantially tar-free. Heat is recovered from this tar-free gas after only a simple cleaning of particulate matter, as may be provided by a cyclone separator. The discharge of gas out the solids inlet end of the kiln and the gas discharged out the solids discharge end of the kiln, is adjustably proportioned relative to each other so that at least some high temperature tar-free gas will mix inside the kiln with the lower temperature tar-containing gas, in an amount sufficient to keep such mixed gases at a temperature high enough to avoid the tars condensing on equipment surfaces. Several process parameters are disclosed for adjusting the proportion of the gas flows out each end of the kiln to maintain the aforesaid condition of both gas streams.

  14. Validation of chemistry models employed in a particle simulation method

    NASA Technical Reports Server (NTRS)

    Haas, Brian L.; Mcdonald, Jeffrey D.

    1991-01-01

    The chemistry models employed in a statistical particle simulation method, as implemented in the Intel iPSC/860 multiprocessor computer, are validated and applied. Chemical relaxation of five-species air in these reservoirs involves 34 simultaneous dissociation, recombination, and atomic-exchange reactions. The reaction rates employed in the analytic solutions are obtained from Arrhenius experimental correlations as functions of temperature for adiabatic gas reservoirs in thermal equilibrium. Favorable agreement with the analytic solutions validates the simulation when applied to relaxation of O2 toward equilibrium in reservoirs dominated by dissociation and recombination, respectively, and when applied to relaxation of air in the temperature range 5000 to 30,000 K. A flow of O2 over a circular cylinder at high Mach number is simulated to demonstrate application of the method to multidimensional reactive flows.

  15. Hydraulically refueled battery employing a packed bed metal particle electrode

    SciTech Connect

    Siu, S.C.; Evans, J.W.

    1998-12-15

    A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode is described. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell. 15 figs.

  16. Hydraulically refueled battery employing a packed bed metal particle electrode

    SciTech Connect

    Siu, Stanley C.; Evans, James W.

    1998-01-01

    A secondary zinc air cell, or another selected metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically, two embodiments of a cell, one that is capable of being hydraulically recharged, and a second that is capable of being either hydraulically or electrically recharged. Additionally, each cell includes a sloped bottom portion to cause stirring of the electrolyte/metal particulate slurry when the cell is being hydraulically emptied and refilled during hydraulically recharging of the cell.

  17. Slagging rotary kiln

    SciTech Connect

    Frericks, R.J.; Price, J.H. Jr.

    1993-08-24

    An improved kiln is described for burning waste, the kiln having a rotatable refractory lined kiln drum with a raised front nose ring and a front wall with a smile shaped oil cooled refractory support cantilevered from the front wall to support a cantilevered refractory portion which extends into the rotatable drum wherein the improvement comprises: the smile shaped oil cooled refractory support having a length so that its distal end is adjacent the edge of the front end of the front nose ring of the rotatable kiln drum; the nose ring having a height so that it extends radially inwardly beyond the lower portion of the smile shaped oil cooled refractory support; and the cantilevered refractory portion extends into the rotatable kiln drum beyond the smile shaped front wall support structure and over the heightened nose ring, whereby combustion air flows over the distal end of the smile shaped oil cooled refractory support to provide cooling, increase the life thereof and substantially reduce the amount of waste running over the front nose ring.

  18. Seals cap rotary kiln emissions

    SciTech Connect

    Gunkle, D.W. )

    1993-09-01

    The possibility of producing fugitive emissions is one of the most critical aspects of an incineration system. Whether such a system processes hazardous, medical, mixed or municipal waste, fugitive emissions are of special concern to system operators and the public alike. Effectively designed rotary-kiln seals can reduce fugitive emissions to acceptable, minimal levels. Modern air monitoring systems track incineration site emissions. Possible emissions sources include excavation and transfer sites, storage areas, material-feed systems, rotary kiln seals, and exhaust stacks. Several options are available for rotary-kiln seals. Six are discussed here: labyrinth; overlapping spring plate; graphite block; pneumatic; shrouded; and overpressure. Kiln seals are used to prevent process gases from escaping or ambient air from entering a rotary kiln uncontrolled. They are not designed to function as material seals, or prevent spills of solids or liquids. Seal design involves considering differential pressure produced by a kiln's internal-to-external temperature, pressure excursions (explosions) and material spills.

  19. Solar-heated rotary kiln

    DOEpatents

    Shell, P.K.

    1982-04-14

    A solar heated rotary kiln utilized for decomposition of materials, such as zinc sulfate is disclosed. The rotary kiln has an open end and is enclosed in a sealed container having a window positioned for directing solar energy into the open end of the kiln. The material to be decomposed is directed through the container into the kiln by a feed tube. The container is also provided with an outlet for exhaust gases and an outlet for spent solids, and rests on a tiltable base. The window may be cooled and kept clear of debris by coolant gases.

  20. A particle accelerator employing transient space charge potentials

    DOEpatents

    Post, R.F.

    1988-02-25

    The invention provides an accelerator for ions and charged particles. The plasma is generated and confined in a magnetic mirror field. The electrons of the plasma are heated to high temperatures. A series of local coils are placed along the axis of the magnetic mirror field. As an ion or particle beam is directed along the axis in sequence the coils are rapidly pulsed creating a space charge to accelerate and focus the beam of ions or charged particles. 3 figs.

  1. Determining controls on element concentrations in cement kiln dust leachate

    SciTech Connect

    Duchesne, J.; Reardon, E.J.

    1998-12-31

    Cement kiln dust is a waste residue composed chiefly of oxidized, anhydrous, micron-sized particles generated as a by-product of the manufacture of Portland cement. When cement kiln dust is brought into contact with water, high concentrations of potassium, sulfate and caustic alkalinity are leached. Other constitutents are leached to a lesser extent. The objective of this study was to determine whether the concentration of a given chemical constituent in kiln dust leachate is controlled by the precipitation of a secondary mineral phase or whether its concentration depends on its initial availability to the leachate solution and its subsequent diffusive flux from hydrating particles with time. Differentiating between these two distinctive styles of leaching behavior is necessary to predict the chemical composition of kiln dust leachate under dynamic flow conditions in disposal environments. Evidence of solubility control was found for Si, Ca, Mg, Al, Zn, Ti, Sr, and Ba. The concentrations of Na, Cl, K, Mo, Cr and Se, however, were found to have no solubility control. Because of the observed lack of solubility control and the particularly high concentrations of Cr and Mo in kiln dust leachate, The authors tested two additives to reduce their concentrations: (1) aluminum oxide to promote the precipitation of calcium aluminosulfates and the proxying of chromate and molybdate for sulfate in their structures; and (2) iron metal to promote the reduction of chromate and molybdate to lower valent and less soluble forms. Neither treatment had any effect on the concentration levels of Cr and Mo in solution.

  2. Waste fuel delivery to long kilns

    SciTech Connect

    Benoit, M.R.; Hansen, E.R.; Reese, T.J.

    1993-07-06

    Method for charging combustible waste to a rotary cement kiln is described comprising a rotating kiln cylinder to burn said waste in contact with in-process mineral material, said method comprising the steps of (1) modifying said cement kiln to provide a port in the rotary kiln cylinder at a point along its length where waste charged through the port will contact calcining mineral during kiln operation, said port having a closure moveable between a port-closed and a port-opened position; (2) positioning the waste in alignment with said port during rotation of the kiln cylinder; (3) moving the port closure to the port-opened position and charging the waste into the kiln through the port; (4) moving the port closure to the port-closed position; and (5) repeating steps 2-4 during kiln operation whereby combustible waste is used to provide up to 40% or more of the energy requirements of kiln operation.

  3. Kiln control for incinerating waste

    SciTech Connect

    Byerly, H.L.; Kuhn, B.R.; Matter, D.C.; Vassiliou, E.

    1993-07-20

    An incinerating kiln device is described capable of controlling the viscosity of molten slag contained within and discharged from the kiln, the device comprising a rotary kiln having a substantially cylindrical shape, an outside skin, a center axis, an inlet, and an outlet opposite the inlet, the kiln being inclined so that the slag exits from the outlet at a discharge position, and wherein the center axis and a line crossing the center axis and having the direction of gravity define a plane of zero position, the distance between the discharge position and the plane of zero position being an indirect measure of the angular viscosity of the slag, the higher said distance the higher the angular viscosity; first detection means at the outlet of the kiln for detecting the distance between the discharge position and the plane of zero position, thus determining the angular viscosity of the slag; and means for correcting the viscosity of the slag, if the distance between the plane of zero position and the discharge position deviates from a desired value, by feeding an additive to the inlet of the kiln.

  4. Residence time distribution and material flow studies in a rotary kiln

    NASA Astrophysics Data System (ADS)

    Sai, P. S. T.; Surender, G. D.; Damodaran, A. D.; Suresh, V.; Philip, Z. G.; Sankaran, K.

    1990-12-01

    Experiments were conducted in a rotary kiln containing ilmenite particles to study the residence time distribution (RTD) of low-density particles, holdup, and bed depth profile. The variables include feed rate of solids, slope and rotational speed of the kiln, type and size of the tracer, and dam height. Correlations are presented for mean residence time, dispersion number, holdup, and steady-state throughput of solids in terms of the process variables. A simple method is proposed to estimate the dam height that gives rise to a flat profile of solids bed along the length of the kiln.

  5. Kiln emissions and potters' exposures.

    PubMed

    Hirtle, B; Teschke, K; van Netten, C; Brauer, M

    1998-10-01

    Some ten thousand British Columbia potters work in small private studios, cooperative facilities, educational institutions, or recreation centers. There has been considerable concern that this diffuse, largely unregulated activity may involve exposures to unacceptable levels of kiln emissions. Pottery kiln emissions were measured at 50 sites--10 from each of 5 categories: professional studios, recreation centers, elementary schools, secondary schools, and colleges. Area monitoring was done 76 cm from firing kilns and 1.6 m above the floor to assess breathing zone concentrations of nitrogen dioxide, carbon monoxide, sulfur dioxide, fluorides, aldehydes, aluminum, antimony, arsenic, barium, beryllium, boron, cadmium, chromium, cobalt, copper, gold, iron, lead, lithium, magnesium, manganese, mercury, nickel, selenium, silver, vanadium, and zinc. Personal exposures to the same metals were measured at 24 sites. Almost all measured values were well below permissible concentrations for British Columbia work sites and American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit values (TLVs) with the following two exceptions. A single firing duration (495 minute) acrolein measurement adjacent to an electric kiln (0.109 ppm) exceeded these guidelines. One 15-minute sulfur dioxide measurement collected adjacent to a gas kiln (5.7 ppm) exceeded the ACGIH short-term exposure limit. The fact that concentrations in small, ventilated kiln rooms ranked among the highest measured gives rise to concern that unacceptable levels of contamination may exist where small kiln rooms remain unventilated. Custom designed exhaust hoods and industrial heating, ventilating, and air-conditioning systems were the most effective ventilation strategies. Passive diffusion and wall/window fans were least effective.

  6. Electrically recharged battery employing a packed/spouted bed metal particle electrode

    DOEpatents

    Siu, Stanley C.; Evans, James W.; Salas-Morales, Juan

    1995-01-01

    A secondary metal air cell, employing a spouted/packed metal particle bed and an air electrode. More specifically a zinc air cell well suited for use in electric vehicles which is capable of being either electrically or hydraulically recharged.

  7. The Kiln Drying of Wood for Airplanes

    NASA Technical Reports Server (NTRS)

    Tiemann, Harry D

    1919-01-01

    This report is descriptive of various methods used in the kiln drying of woods for airplanes and gives the results of physical tests on different types of woods after being dried by the various kiln-drying methods.

  8. A Pottery Electric Kiln Using Decompression

    NASA Astrophysics Data System (ADS)

    Naoe, Nobuyuki; Yamada, Hirofumi; Nakayama, Tetsuo; Nakayama, Minoru; Minamide, Akiyuki; Takemata, Kazuya

    This paper presents a novel type electric kiln which fires the pottery using the decompression. The electric kiln is suitable for the environment and the energy saving as the pottery furnace. This paper described the baking principle and the baking characteristic of the novel type electric kiln.

  9. Transient phenomena in rotary-kiln incineration

    SciTech Connect

    Linak, W.P.; Kilgroe, J.D.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E.

    1989-01-01

    This paper describes results of an ongoing experimental investigation at the U.S. EPA into the waste properties and kiln parameters that determine both the instantaneous intensity and the total magnitude of transient puffs leaving the kiln. (NOTE: The batch introduction of waste-filled drums or containers into practical rotary-kiln incinerators can lead to transient overcharging conditions which, for brevity, are here denoted as 'puffs.') The experimental apparatus utilized was a 73-kW laboratory rotary-kiln simulator. Surrogate solid wastes (plastic rods) and surrogate liquid wastes (on corncob sorbent in cardboard containers) were investigated. A statistically designed parametric study was used to determine the extent to which waste and kiln variables (e.g., charge mass, charge surface area, charge composition, kiln temperature, and kiln rotation speed) affected the intensity (hydrocarbon peak height) and magnitude (hydrocarbon peak area) of puffs.

  10. Burning chemical wastes as fuels in cement kilns

    SciTech Connect

    Lauber, J.D.

    1982-07-01

    Hazardous wastes in the environment represent one of our most serious problems. Ever increasing quantities of toxic wastes have contaminated our land, air, and water. Lack of adequate hazardous waste disposal facilities is a critical problem. Landfilling toxic wastes is no longer considered safe. The tragedy of the Love Canal has demonstrated the need for proper hazardous waste disposal facilities. The best organic chemical waste disposal method is process incineration. Cement kilns have been used for burning toxic chemical industrial wastes in Canada, Michigan, New York, Sweden, etc. Existing cement kilns, when properly operated, can destroy most organic chemical wastes. Even the most complex chlorinated hydrocarbons, including PCB can be completely destroyed during normal cement kiln operations, with minimal emissions to the environment. Burning toxic chemical wastes in cement kilns, and other mineral industries, is mutually beneficial to both industry, who generates such wastes, and to society and government, who want to dispose properly of such wastes in a safe, environmentally acceptable manner. The added benefit of energy conservation is important, since large quantities of valuable fuel can be saved in the manufacture of cement when such techniques are employed. (Refs. 16).

  11. Rotary kilns - transport phenomena and transport processes

    SciTech Connect

    Boateng, A.

    2008-01-15

    Rotary kilns and rotating industrial drying ovens are used for a wide variety of applications including processing raw minerals and feedstocks as well as heat-treating hazardous wastes. They are particularly critical in the manufacture of Portland cement. Their design and operation is critical to their efficient usage, which if done incorrectly can result in improperly treated materials and excessive, high fuel costs. This book treats all engineering aspects of rotary kilns, including thermal and fluid principles involved in their operation, as well as how to properly design an engineering process that uses rotary kilns. Chapter 1: The Rotary Kiln Evolution and Phenomenon Chapter 2: Basic Description of Rotary Kiln Operation Chapter 3: Freeboard Aerodynamic Phenomena Chapter 4: Granular Flows in Rotary Kilns Chapter 5: Mixing and Segregation Chapter 6: Combustion and Flame - includes section on types of fuels used in rotary kilns, coal types, ranking and analysis, petroleum coke combustion, scrap tire combustion, pulverized fuel (coal/coke) firing in kilns, pulverized fuel delivery and firing systems. Chapter 7: Freeboard Heat Transfer Chapter 8: Heat Transfer Processes in the Rotary Kiln Bed Chapter 9: Mass and Energy Balance Chapter 10: Rotary Kiln Minerals Process Applications.

  12. Electrically recharged battery employing a packed/spouted bed metal particle electrode

    SciTech Connect

    Siu, S.C.; Evans, J.W.; Salas-Morales, J.

    1995-08-15

    A secondary metal air cell, employing a spouted/packed metal particle bed and an air electrode, is described. More specifically a zinc air cell well suited for use in electric vehicles which is capable of being either electrically or hydraulically recharged. 5 figs.

  13. 7. Front of northern kiln group, looking north. Vents are ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    7. Front of northern kiln group, looking north. Vents are visible in all kilns, in two rows above present grade. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  14. 62. INTERIOR VIEW OF THE LIME KILN BUILDING, LOOKING AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    62. INTERIOR VIEW OF THE LIME KILN BUILDING, LOOKING AT THE LIME KILNS AND MOTOR DRIVES FOR THE KILNS. (DATE UNKNOWN). - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  15. Apparatus for treating cement kiln dust

    SciTech Connect

    Galli, R.

    1986-04-22

    An apparatus is described for treating cement kiln dust comprising an elongate reaction chamber, kiln dust entry means in the reaction chamber, atomized-spray nozzles in the reaction chamber for introducing atomized spray to kiln dust, separate conduits for liquid and gas separately connected to the atomized-spray nozzles for atomizing liquid by gas to form a fog of the liquid in an atmosphere of the gas, mixing means in the reaction chamber for mixing the kiln dust in contact with the fog and gaseous atmosphere of the reaction chamber, discharge means at one end of the reaction chamber for discharging the mixed and contacted kiln dust product from the reaction chamber. The kiln dust entry means are located in an upper region of the reaction chamber for depositing kiln dust gravitationally to a lower region of the reaction chamber. The atomized-spray nozzles are located in the upper region of the reaction chamber for depositing fog on kiln dust during mixing thereof, gas entry means on the reaction chamber for delivering gas to the reaction chamber for reaction with kiln dust and fog, gas exit means on the reaction chamber for discharging gas products from the reaction chamber. The gas entry and exit means are at opposite ends of the reaction chamber, and pre-entry liquid atomizing spray means in the gas entry means for treating gas by atomized liquid spray to effectively saturate the gas before delivery to the reaction chamber.

  16. Transient phenomena in rotary kiln incineration

    SciTech Connect

    Linak, W.P.; Kilgroe, J.D.; Wendt, J.O.; Mc Sorley, J.A.; Dunn, J.E.

    1986-01-01

    This paper describes results of an ongoing experimental investigation at the U.S. Environmental Protection Agency into the waste properties and kiln parameters that determine both the instantaneous intensity and the total magnitude of transient puffs leaving the kiln. The experimental apparatus utilized was a 73 kW (250,000 Btu/hr) laboratory rotary kiln simulator. Surrogate solid wastes in the form of plastic rods and surrogate liquid wastes on corncob sorbent in cardboard containers were investigated. A statistically designed parametric study was used to determine the extent to which waste and kiln variables (such as charge mass, charge surface area, charge composition, kiln temperature, and kiln rotation speed) affected the intensity (hydrocarbon peak height) and magnitude (hydrocarbon peak area) of puffs. Results demonstrate the relative ease with which failure conditions are achieved, even at high excess air values and high kiln temperatures. Transient puffs arising from even innocuous surrogate wastes can contain a number of hazardous compounds. Increasing kiln temperature and kiln rotation speed can cause an adverse effect on puff intensity, probably due to increased devolatilization rates.

  17. Techniques employed for detection of hot particles in the marine environment.

    PubMed

    Pillsbury, G D

    2007-09-01

    During the decommissioning of the Maine Yankee nuclear plant, several methods were developed and employed to survey for hot particles in the marine environment surrounding the site. The methods used and the sensitivities achieved in the search for environmentally dispersed particles during the various decommissioning activities performed are described in detail. Surveys were performed on dry soil, exposed marine sediment and submerged marine sediment. Survey techniques ranged from the use of the basic NaI detector coupled to a count rate meter to an intrinsic germanium detector deployed in a submarine housing coupled to a multi-channel analyser. The initial surveys consisted of collecting samples of marine sediment, spreading them out over a 1 m2 surface in a thin layer, and scanning the deposited sediment by hand using a 5 cm by 5 cm NaI detector coupled to a standard count rate meter. This technique was later replaced by walkover scans with the 5 cm by 5 cm NaI detector moved in a serpentine pattern over the sediment surface. By coupling the detector to a 'smart meter', an alarm set point could be used to alert the surveyor to the presence of a particle within the instrument's field of view. A similar technique, with the detector mounted in a watertight housing secured to the end of a pole, was also employed to scan underwater locations. The most sensitive method developed for performing underwater surveys was the use of the intrinsic germanium detector placed in a submarine housing. Detailed descriptions of the methods employed and the results obtained are presented. This work demonstrates that there are several approaches to surveying for discrete particles in the marine environment and the relative merits of each are considered.

  18. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Lime Kiln Valley. 9.27... Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley.” (b) Approved Map. The appropriate map for determining the boundaries of the Lime Kiln...

  19. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Lime Kiln Valley. 9.27... Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley.” (b) Approved Map. The appropriate map for determining the boundaries of the Lime Kiln...

  20. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Lime Kiln Valley. 9.27... Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley.” (b) Approved Map. The appropriate map for determining the boundaries of the Lime Kiln...

  1. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lime Kiln Valley. 9.27... Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley.” (b) Approved Map. The appropriate map for determining the boundaries of the Lime Kiln...

  2. 27 CFR 9.27 - Lime Kiln Valley.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Lime Kiln Valley. 9.27... Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley.” (b) Approved Map. The appropriate map for determining the boundaries of the Lime Kiln...

  3. Mass balance of dioxins over a cement kiln in China.

    PubMed

    Li, Yeqing; Chen, Tong; Zhang, Jiang; Meng, Weijie; Yan, Mi; Wang, Huanzhong; Li, Xiaodong

    2015-02-01

    The cement production process may be a potential source of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs, "dioxins"), due to the widespread distribution of dioxins and potential precursors in raw materials and to conditions favorable to de novo formation in the heat exchangers. The emission, gas/particle distribution, and mass balance of PCDD/Fs were investigated at a typical state-of-the-art Chinese cement kiln. Input and output inventories were established for three campaigns, including two in normal operation and one while co-processing refuse derived fuel (RDF). Sample analysis from stack gas, cement kiln dust, raw meal, fly dust and clinker for the analysis of PCDD/Fs were reported in this study. Dioxins were also analyzed at various positions in the pre-heater, presenting an adsorption-desorption circulation process of PCDD/Fs. The over-all dioxin mass balance was negative, indicating that this cement kiln is not a source but a sink process of dioxins.

  4. Risks associated with waste-fuel use in cement kilns

    SciTech Connect

    Mix, T.W.; Murphy, B.L.

    1984-02-01

    Risks from lead emissions in kiln dust, released of materials including dioxins during upset conditions, and transportation related accidents are described for a cement kiln burning waste fuels. The disposition of the lead fed to the kiln may be deduced both from prior cement-kiln test burns of hazardous wastes and from studies of municipal refuse incinerators. Cement-kiln test data on the disposition of lead is included.

  5. On flow induced kinetic diffusion and rotary kiln bed burden heat transport

    SciTech Connect

    Boateng, A.A.

    1997-07-01

    The cross-section of a partially-filled cylindrical kiln rotating on its horizontal axis and processing granular solids produces a shear zone (active layer) at the free surface which grows with the kiln's rotational rate. The active layer, although relatively thin, compared with the rest of the bed burden, drives all physical/chemical reactions. This is because of the high rate of surface renewal which, in turn, promotes heat exchange between the exposed surface and the higher temperature freeboard gas. Unlike packed beds, particulate diffusion induced by the flow of granules, adds a significant component to the overall heat transfer in the bed. Problem formulation and modeling of heat conduction using flow fields derived from experiments suggest that at slow kiln speeds the diffusion effect may not be recognized due to long term duration of particle contacts and hence packed-bed heat conduction models may provide adequate characterization. However, at moderate and high kiln speeds particle collisions are short-termed and kinetic diffusion contributes to the effective thermal conductivity by as much as tenfold thereby resulting in a well-mixed conditions and a homogeneous bed temperature. Industrial processing ramifications such as kiln speed control and product quality are discussed hereafter.

  6. The desorption of toluene from a montmorillonite clay adsorbent in a rotary kiln environment

    SciTech Connect

    Owens, W.D.; Silcox, G.D.; Lighty, J.S.; Xiao Xue Deng; Pershing, D.W. ); Cundy, V.A.; Leger, C.B.; Jakway, A.L. )

    1992-05-01

    The vaporization of toluene from pre-dried, 3 mm montmorillonite clay particles was studied in a 130 kW pilot-scale rotary kiln with inside dimensions of 0.61 by 0.61 meters. Vaporization rates were obtained with a toluene weight fraction of 0.25 percent as a function of kiln fill fractions from 3 to 8 percent, rotation rates from 0.1 to 0.9 rpm, and kiln wall temperatures from 189 to 793 C. Toluene desorption rates were obtained from gas-phase measurements and interpreted using a desorption model that incorporates the slumping frequency of the solids, the fill fraction of the kiln, the diffusion of toluene in the bed, and the rate of particle desorption using an Arrhenius-type expression that is a function of bed temperature and average bed concentration. The model included three adjustable desorption parameters which were obtained by fitting the experimental data at one set of conditions with a least squares technique. Solid and kiln-wall temperatures were continuously recorded and used in the model at predicting the effects of fill fraction and rotation rate over a range of temperatures. A methodology for predicting full-scale performance was developed. Full-scale toluene desorption predictions were completed for different operating temperatures.

  7. Coal desulfurization in a rotary kiln combustor

    SciTech Connect

    Cobb, J.T. Jr.

    1992-09-11

    The purpose of this project was to demonstrate the combustion of coal and coal wastes in a rotary kiln reactor with limestone addition for sulfur control. The rationale for the project was the perception that rotary systems could bring several advantages to combustion of these fuels, and may thus offer an alternative to fluid-bed boilers. Towards this end, an existing wood pyrolysis kiln (the Humphrey Charcoal kiln) was to be suitably refurbished and retrofitted with a specially designed version of a patented air distributor provided by Universal Energy, Inc. (UEI). As the project progressed beyond the initial stages, a number of issues were raised regarding the feasibility and the possible advantages of burning coals in a rotary kiln combustor and, in particular, the suitability of the Humphrey Charcoal kiln as a combustor. Instead, an opportunity arose to conduct combustion tests in the PEDCO Rotary Cascading-Bed Boiler (RCBB) commercial demonstration unit at the North American Rayon CO. (NARCO) in Elizabethton, TN. The tests focused on anthracite culm and had two objectives: (a) determine the feasibility of burning anthracite culms in a rotary kiln boiler and (b) obtain input for any further work involving the Humphrey Charcoal kiln combustor. A number of tests were conducted at the PEDCO unit. The last one was conducted on anthracite culm procured directly from the feed bin of a commercial circulating fluid-bed boiler. The results were disappointing; it was difficult to maintain sustained combustion even when large quantities of supplemental fuel were used. Combustion efficiency was poor, around 60 percent. The results suggest that the rotary kiln boiler, as designed, is ill-suited with respect to low-grade, hard to burn solid fuels, such as anthracite culm. Indeed, data from combustion of bituminous coal in the PEDCO unit suggest that with respect to coal in general, the rotary kiln boiler appears inferior to the circulating fluid bed boiler.

  8. Microwave radiometry for cement kiln temperature measurements.

    PubMed

    Stephan, Karl D; Wang, Lingyun; Ryza, Eric

    2007-01-01

    The maximum temperature inside a cement kiln is a critical operating parameter, but is often difficult or impossible to measure. We present here the first data that show a correlation between cement kiln temperature measured using a microwave radiometer and product chemistry over an eight-hour period. The microwave radiometer senses radiation in the 12-13 GHz range and has been described previously [Stephan and Pearce (2002), JMPEE 37: 112-124].

  9. Jet mixing in a down-scaled model of a rotary kiln

    NASA Astrophysics Data System (ADS)

    Larsson, Sofia; Johansson, Simon

    2015-11-01

    Rotary kilns are large, cylindrical, rotating ovens with a burner in one end that are used in various industrial processes to heat up materials to high temperatures. Kiln burners are characterized by long diffusion flames where the combustion process is largely controlled by turbulent diffusion mixing between the burner fuel jet and the surrounding combustion air. The combustion air flow patterns have a significant effect on the mixing and hence the combustion efficiency and flame shape, motivating a systematic study of the kiln aerodynamics and the mixing characteristics. In this work, a downscaled, isothermal model of a rotary kiln is investigated experimentally through simultaneous particle image velocimetry and planar laser-induced fluorescence measurements. The kiln is modeled as a cylinder with three inlets in one end; two semicircular-shaped inlets for what is called the secondary fluid divided by a wall in between, called the back plate, where the burner nozzle is located. Three momentum flux ratios of the secondary fluid are investigated, and the interaction with the burner jet is scrutinized. It is found that the burner jet characteristics, its mixing with the secondary fluid and the resulting flow field surrounding the jet are dependent on the momentum flux ratio.

  10. CFD modeling using PDF approach for investigating the flame length in rotary kilns

    NASA Astrophysics Data System (ADS)

    Elattar, H. F.; Specht, E.; Fouda, A.; Bin-Mahfouz, Abdullah S.

    2016-12-01

    Numerical simulations using computational fluid dynamics (CFD) are performed to investigate the flame length characteristics in rotary kilns using probability density function (PDF) approach. A commercial CFD package (ANSYS-Fluent) is employed for this objective. A 2-D axisymmetric model is applied to study the effect of both operating and geometric parameters of rotary kiln on the characteristics of the flame length. Three types of gaseous fuel are used in the present work; methane (CH4), carbon monoxide (CO) and biogas (50 % CH4 + 50 % CO2). Preliminary comparison study of 2-D modeling outputs of free jet flames with available experimental data is carried out to choose and validate the proper turbulence model for the present numerical simulations. The results showed that the excess air number, diameter of kiln air entrance, radiation modeling consideration and fuel type have remarkable effects on the flame length characteristics. Numerical correlations for the rotary kiln flame length are presented in terms of the studied kiln operating and geometric parameters within acceptable error.

  11. Gas pollution control apparatus and method and wood drying system employing same

    SciTech Connect

    Eatherton, J.R.

    1984-02-14

    Pollution control apparatus and method are disclosed in which hot exhaust gas containing pollutants including solid particles and hydrocarbon vapors is treated by transmitting such exhaust gas through a container containing wood members, such as wood chips, which serve as a filter media for filtering out such pollutants by causing such solids to deposit and such hydrocarbon vapors to condense upon the surface of the wood members. The contaminated wood chips are discharged from the filter and further processed into chip board or other commercial wood products thereby disposing of the pollutants. Lumber may be used as the wood members of the filter in a lumber kiln by deposition of solid particles on the rough surface of such lumber. The contaminated surfaces of the lumber are removed by a planer which produces a smooth finished lumber and contaminated wood chips that may be processed into chip board or other commercial wood products. A wood drying system employing such pollution control apparatus and method includes a hot air dryer for wood or other organic material, such as a wood chip rotary dryer or a wood veneer dryer, which produces hot exhaust gases containing pollutants including hydrocarbon vapors and solid particles. This hot exhaust air is transmitted through a lumber kiln to dry lumber thereby conserving heat energy and causing solid particle pollutants to deposit on the surface of the lumber. The kiln exhaust air containing solid and hydrocarbon vapor pollutants is then transmitted up through a filter stack of wood chips.

  12. VIEW OF LIME KILN BUILDING LOOKING NORTHWEST, SHOWING STONE ELEVATOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF LIME KILN BUILDING LOOKING NORTHWEST, SHOWING STONE ELEVATOR (ON THE LEFT) AND SOUTH CONVEYOR. - Solvay Process Company, Lime Kiln Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  13. General view looking west from eastern edge of complex. Kilns ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    General view looking west from eastern edge of complex. Kilns have been demolished but kiln stacks still stand. - Harbison-Walker Refractories Company, West end of Shirley Street, Mount Union, Huntingdon County, PA

  14. VIEW OF MLT BUILDING (LIME KILN BUILDING DIRECTLY BEHIND IT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF MLT BUILDING (LIME KILN BUILDING DIRECTLY BEHIND IT WITH GOOD VIEW OF SKIP CAR TRACK) LOOKING EAST. - Solvay Process Company, Lime Kiln Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  15. 4. Front of isolated (southernmost) kiln. Visible through the doorway ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Front of isolated (southernmost) kiln. Visible through the doorway are temporary supports installed in 1986. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  16. 11. Remains of Douglasfir cordwood abandoned when kilns ceased operation, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    11. Remains of Douglas-fir cordwood abandoned when kilns ceased operation, looking northeast. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  17. 63. INTERIOR VIEW OF THE LIME KILN BUILDING, LOOKING AT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. INTERIOR VIEW OF THE LIME KILN BUILDING, LOOKING AT THE FIRE BOX AND KILN FOR DILLUTANT. APRIL 22, 1919. - United States Nitrate Plant No. 2, Reservation Road, Muscle Shoals, Muscle Shoals, Colbert County, AL

  18. 40 CFR 63.1344 - Operating limits for kilns and in-line kiln/raw mills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... CATEGORIES National Emission Standards for Hazardous Air Pollutants From the Portland Cement Manufacturing... sufficient cement kiln dust to maintain the desired product quality. (i) New and reconstructed kilns and...

  19. 7 CFR 300.2 - Dry Kiln Operator's Manual.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Dry Kiln Operator's Manual. 300.2 Section 300.2... SERVICE, DEPARTMENT OF AGRICULTURE INCORPORATION BY REFERENCE § 300.2 Dry Kiln Operator's Manual. (a) The Dry Kiln Operator's Manual, which was published in August 1991 as Agriculture Handbook No. 188 by...

  20. 7 CFR 300.2 - Dry Kiln Operator's Manual.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Dry Kiln Operator's Manual. 300.2 Section 300.2... SERVICE, DEPARTMENT OF AGRICULTURE INCORPORATION BY REFERENCE § 300.2 Dry Kiln Operator's Manual. (a) The Dry Kiln Operator's Manual, which was published in August 1991 as Agriculture Handbook No. 188 by...

  1. 7 CFR 300.2 - Dry Kiln Operator's Manual.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Dry Kiln Operator's Manual. 300.2 Section 300.2... SERVICE, DEPARTMENT OF AGRICULTURE INCORPORATION BY REFERENCE § 300.2 Dry Kiln Operator's Manual. (a) The Dry Kiln Operator's Manual, which was published in August 1991 as Agriculture Handbook No. 188 by...

  2. 7 CFR 300.2 - Dry Kiln Operator's Manual.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Dry Kiln Operator's Manual. 300.2 Section 300.2... SERVICE, DEPARTMENT OF AGRICULTURE INCORPORATION BY REFERENCE § 300.2 Dry Kiln Operator's Manual. (a) The Dry Kiln Operator's Manual, which was published in August 1991 as Agriculture Handbook No. 188 by...

  3. 7 CFR 300.2 - Dry Kiln Operator's Manual.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Dry Kiln Operator's Manual. 300.2 Section 300.2... SERVICE, DEPARTMENT OF AGRICULTURE INCORPORATION BY REFERENCE § 300.2 Dry Kiln Operator's Manual. (a) The Dry Kiln Operator's Manual, which was published in August 1991 as Agriculture Handbook No. 188 by...

  4. 3. Rear elevations of kilns, looking south. Note loading door ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Rear elevations of kilns, looking south. Note loading door and position of kilns on the slope. This placement facilitated access to the upper door. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  5. 5. Front of northern kiln group, looking northwest. Note cables ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. Front of northern kiln group, looking northwest. Note cables encircling the walls. Barricades at doorway were placed by Forest Service to prevent cattle from entering the kilns. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  6. 6. Front of northern kiln group, looking west. Vents, plugged ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Front of northern kiln group, looking west. Vents, plugged with loose bricks and clay, are distinguishable in the nearest and farthest kilns, slightly above current grade. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  7. Brick Kiln Emissions Quantified with the Aerodyne Mobile Laboratory During the Short Lived Climate Forcing (SLCF) 2013 Campaign in Guanajuato Mexico

    NASA Astrophysics Data System (ADS)

    Fortner, E.; Knighton, W. B.; Herndon, S.; Roscioli, J. R.; Zavala, M.; Onasch, T. B.; Jayne, J. T.; Worsnop, D. R.; Kolb, C. E.; Molina, L. T.

    2013-12-01

    Brick kiln emissions are suspected to be a major source of atmospheric black carbon (BC) in developing countries; and black carbon's role as a short lived climate forcing (SLCF) pollutant is widely recognized. The SLCF-Mexico brick kiln study was conducted from 12-17 March 2013 in Mexico's Guanajuato state. Three different types of brick kilns were investigated (MK2, traditional, and traditional three tier) providing data on the effects of different kiln designs on particle and gas phase emissions. The BC and gaseous combustion emissions from these kilns were measured during both the fire stage and the subsequent smoldering stage with real-time instruments deployed on the Aerodyne Mobile Laboratory, and quantified utilizing flux tracer gases released adjacent to the brick kiln. This method allows examination of the brick kiln plume's evolution as it transits downwind from the source. Particulate measurements conducted by the mobile laboratory included the multi angle absorption photometer (MAAP) to measure black carbon mass, cavity attenuated phase shift (CAPSext) monitor to measure extinction and soot particle aerosol mass spectrometer (SP-AMS) measurements of black carbon. The SP-AMS instrument combines the ability to measure black carbon with the ability to determine the chemical composition of the other particulate matter (PM) components associated with black carbon particles. The variance of PM chemical composition will be examined as a function of burning stage and kiln type and compared to other black carbon PM sources. Gas phase exhaust species measured included CO, CO2, NOx, SO2, CH4, C2H6, as well as a variety of VOCs (acetonitrile, benzene etc.) measured with a PTR-MS instrument. All of these measurements will be examined to construct emission ratios evaluating how these vary with different kiln types and different firing conditions. The evolution of particulate matter and gas phase species as they transit away from the source will also be examined.

  8. Environmental impact of incineration of calorific industrial waste: rotary kiln vs. cement kiln.

    PubMed

    Vermeulen, Isabel; Van Caneghem, Jo; Block, Chantal; Dewulf, Wim; Vandecasteele, Carlo

    2012-10-01

    Rotary kiln incinerators and cement kilns are two energy intensive processes, requiring high temperatures that can be obtained by the combustion of fossil fuel. In both processes, fossil fuel is often substituted by high or medium calorific waste to avoid resource depletion and to save costs. Two types of industrial calorific waste streams are considered: automotive shredder residue (ASR) and meat and bone meal (MBM). These waste streams are of current high interest: ASR must be diverted from landfill, while MBM can no longer be used for cattle feeding. The environmental impact of the incineration of these waste streams is assessed and compared for both a rotary kiln and a cement kiln. For this purpose, data from an extensive emission inventory is applied for assessing the environmental impact using two different modeling approaches: one focusing on the impact of the relevant flows to and from the process and its subsystems, the other describing the change of environmental impact in response to these physical flows. Both ways of assessing emphasize different aspects of the considered processes. Attention is paid to assumptions in the methodology that can influence the outcome and conclusions of the assessment. It is concluded that for the incineration of calorific wastes, rotary kilns are generally preferred. Nevertheless, cement kilns show opportunities in improving their environmental impact when substituting their currently used fuels by more clean calorific waste streams, if this improvement is not at the expense of the actual environmental impact.

  9. Improved non-invasive method for aerosol particle charge measurement employing in-line digital holography

    NASA Astrophysics Data System (ADS)

    Tripathi, Anjan Kumar

    Electrically charged particles are found in a wide range of applications ranging from electrostatic powder coating, mineral processing, and powder handling to rain-producing cloud formation in atmospheric turbulent flows. In turbulent flows, particle dynamics is influenced by the electric force due to particle charge generation. Quantifying particle charges in such systems will help in better predicting and controlling particle clustering, relative motion, collision, and growth. However, there is a lack of noninvasive techniques to measure particle charges. Recently, a non-invasive method for particle charge measurement using in-line Digital Holographic Particle Tracking Velocimetry (DHPTV) technique was developed in our lab, where charged particles to be measured were introduced to a uniform electric field, and their movement towards the oppositely charged electrode was deemed proportional to the amount of charge on the particles (Fan Yang, 2014 [1]). However, inherent speckle noise associated with reconstructed images was not adequately removed and therefore particle tracking data was contaminated. Furthermore, particle charge calculation based on particle deflection velocity neglected the particle drag force and rebound effect of the highly charged particles from the electrodes. We improved upon the existing particle charge measurement method by: 1) hologram post processing, 2) taking drag force into account in charge calculation, 3) considering rebound effect. The improved method was first fine-tuned through a calibration experiment. The complete method was then applied to two different experiments, namely conduction charging and enclosed fan-driven turbulence chamber, to measure particle charges. In all three experiments conducted, the particle charge was found to obey non-central t-location scale family of distribution. It was also noted that the charge distribution was insensitive to the change in voltage applied between the electrodes. The range of voltage

  10. JV Task-Long-Kiln NOx Reduction Study

    SciTech Connect

    Bruce Folkedahl; Joshua Strege; Darren Schmidt; Lingbu Kong

    2008-07-01

    Field sampling was conducted by the Energy & Environmental Research Center at two Lafarge North America cement kiln locations in Canada. Emissions including SO{sub x}, NO{sub x}, and particulate were measured and reported at various locations throughout the kilns. At each site data were collected on two kilns during field sampling. However, only Kiln 1 at the Ravena site was utilized for modeling efforts. Experimental work was then conducted to estimate the effectiveness of various NO{sub x} control techniques on limiting both NO{sub x} and SO{sub x} emissions in cement kiln exhaust. Theory-based models were constructed to estimate both NO{sub x} and SO{sub x} emissions from cement kilns. These models were then applied to estimating the impact of various NO{sub x} control strategies on kiln exhaust emissions. The sulfur model constructed as part of this work was successful at predicting SO{sub 2} emissions and sulfur capture in the Alpena kiln. This model is designed to run as a postprocessing step that uses the output of a NO{sub x} model as input. With an accurate NO{sub x} model, the sulfur model may prove to be a valuable tool in estimating the impact of kiln modifications on sulfur emissions. The NO{sub x} model was also applied to model several operating scenarios on three of Lafarge's kilns: Alpena 20/21, Alpena 22/23, and Ravena 1. The predictions of the flue gas temperature at the kiln feed end, the kiln shell heat loss, the quality of clinker, and the excess O{sub 2} in the flue gas are consistent with the audit data. The developed simulation tool in this project has proven to be an effective way to investigate the NO{sub x} emissions, to optimize kiln performance, and to assess changes in operating condition on kiln performance.

  11. Coal desulfurization in a rotary kiln combustor

    SciTech Connect

    Cobb, J.T. Jr.

    1990-08-15

    BCR National Laboratory (BCRNL) has initiated a project aimed at evaluating the technical and economic feasibility of using a rotary kiln, suitably modified, to burn Pennsylvania anthracite wastes, co-fired with high-sulfur bituminous coal. Limestone will be injected into the kiln for sulfur control, to determine whether high sulfur capture levels can be achieved with high sorbent utilization. The principal objectives of this work are: (1) to prove the feasibility of burning anthracite refuse, with co-firing of high-sulfur bituminous coal and with limestone injection for sulfur emissions control, in a rotary kiln fitted with a Universal Energy International (UEI) air injector system; (2) to determine the emissions levels of SO{sub x} and NO{sub x} and specifically to identify the Ca/S ratios that are required to meet New Source Performance Standards; (3) to evaluate the technical and economic merits of a commercial rotary kiln combustor in comparison to fluidized bed combustors; and, (4) to ascertain the need for further work, including additional combustion tests, prior to commercial application, and to recommend accordingly a detailed program towards this end.

  12. Coal desulfurization in a rotary kiln combustor

    SciTech Connect

    Cobb, J.T. Jr.

    1991-04-22

    The focus of our work during the first quarter of 1991 was on combustion tests at the PEDCO rotary kiln reactor at North American Rayon (NARCO) plant in Elizabethton, TN. The tests had essentially tow related objectives: (a) to obtain basic data on the combustion of anthracite culm in a rotary kiln reactor, and (b) upon the test results, determine how best to proceed with our own planned program at the Humphrey Charcoal kiln in Brookville, PA. The rationale for the tests at PEDCO arose from process analysis which posted red flags on the feasibility of burning low-grade, hard-to-burn fuels like anthracite culms, in the rotary kiln. The PEDCO unit afforded a unique opportunity to obtain some quick answers at low cost. Two different anthracite culm fuels were tested: a so-called Jeddo culm with an average heating value of 7000 Btu/lb, and a relatively poorer culm, and Emerald'' culm, with an average heating value of 5000 Btu/lb. An attempt was also made to burn a blend of the Emerald culm with bituminous coal in 75/25 percent proportions. This report describes the tests, their chronology, and preliminary results. As it turned out, the PEDCO unit is not configured properly for the combustion of anthracite culm. As a result, it proved difficult to achieve a sustained period of steady-state combustion operation, and combustion efficiencies were low even when supplemental fuel was used to aid combustion of the culm. 1 fig., 2 tabs.

  13. Method of operating an oil shale kiln

    DOEpatents

    Reeves, Adam A.

    1978-05-23

    Continuously determining the bulk density of raw and retorted oil shale, the specific gravity of the raw oil shale and the richness of the raw oil shale provides accurate means to control process variables of the retorting of oil shale, predicting oil production, determining mining strategy, and aids in controlling shale placement in the kiln for the retorting.

  14. Cement Kiln Flue Gas Recovery Scrubber Project

    SciTech Connect

    National Energy Technology Laboratory

    2001-11-30

    The Cement Kiln Flue Gas Recovery Scrubber Project was a technical success and demonstrated the following: CKD can be used successfully as the sole reagent for removing SO2 from cement kiln flue gas, with removal efficiencies of 90 percent or greater; Removal efficiencies for HCl and VOCs were approximately 98 percent and 70 percent, respectively; Particulate emissions were low, in the range of 0.005 to 0.007 grains/standard cubic foot; The treated CKD sorbent can be recycled to the kiln after its potassium content has been reduced in the scrubber, thereby avoiding the need for landfilling; The process can yield fertilizer-grade K2SO4, a saleable by-product; and Waste heat in the flue gas can provide the energy required for evaporation and crystallization in the by-product recovery operation. The demonstration program established the feasibility of using the Recovery Scrubber{trademark} for desulfurization of flue gas from cement kilns, with generally favorable economics, assuming tipping fees are available for disposal of ash from biomass combustion. The process appears to be suitable for commercial use on any type of cement kiln. EPA has ruled that CKD is a nonhazardous waste, provided the facility meets Performance Standards for the Management of CKD (U.S. Environmental Protection Agency 1999d). Therefore, regulatory drivers for the technology focus more on reduction of air pollutants and pollution prevention, rather than on treating CKD as a hazardous waste. Application of the Recovery Scrubbe{trademark} concept to other waste-disposal operations, where pollution and waste reductions are needed, appears promising.

  15. Immunotoxicological response of the earthworm Lumbricus terrestris following exposure to cement kiln dusts.

    PubMed

    Massicotte, R; Robidoux, P-Y; Sauvé, S; Flipo, D; Mathiot, A; Fournier, M; Trottier, B

    2004-09-01

    Cement kiln dusts are made of a complex mixture of elements. We have evaluated the potential negative impact of those dusts on the immune system of the earthworm Lumbricus terrestris. We specifically studied cell viability and phagocytic activity of coelomocytes extruded during electrical stimulation. We used two modes of exposures: in vitro, and soil incubation using OECD artificial soil media. Extruded coelomocytes were exposed 18 h in vitro to 10, 100, and 500 mg L(-1) of cement kiln dust particles. The phagocytosis and the cell viability were determined using a double-laser-flow acquisition cytometry system. Using the double laser allows us to use a dichlorofluorescein diacetate (DCFDA) marker to discriminate the biological cells from the cement kiln dusts. Dead cells are marked using propidium iodide (PI). All three exposure levels showed highly significant impacts on cell viability and phagocytic activity. The in vivo soil incubation was performed using 10, 100, and 1000 mg kg(-1) of cement kiln dusts incorporated into the OECD media. Here, to discriminate the biological cells from the mineral dusts we only needed to use PI. The day-to-day variability of the in vivo assay was high and although we can observe an overall reduction in cell viability at the highest concentration tested, no statistically significant effects could be observed on either cell viability or phagocytosis.

  16. Perspectives and limits for cement kilns as a destination for RDF

    SciTech Connect

    Genon, G.; Brizio, E.

    2008-11-15

    RDF, the high calorific value fraction of MSW obtained by conventional separation systems, can be employed in technological plants (mainly cement kilns) in order to obtain a useful energy recovery. It is interesting and important to evaluate this possibility within the general framework of waste-to-energy solutions. The solution must be assessed on the basis of different aspects, namely: technological features and clinker characteristics; local atmospheric pollution; the effects of RDF used in cement kilns on the generation of greenhouse gases; the economics of conventional solid fuels substitution and planning perspectives, from the point of view of the destination of RDF and optimal cement kiln policy. The different experiences of this issue throughout Europe are reviewed, and some applications within Italy are also been considered. The main findings of the study are that the use of RDF in cement kilns instead of coal or coke offers environmental benefits in terms of greenhouse gases, while the formation of conventional gaseous pollutants is not a critical aspect. Indeed, the generation of nitrogen oxides can probably be lower because of lower flame temperatures or lower air excess. The presence of chlorinated micro-pollutants is not influenced by the presence of RDF in fuel, whereas depending on the quality of the RDF, some problems could arise compared to the substituted fuel as far as heavy metals are concerned, chiefly the more volatile ones.

  17. Assessment of air pollutant emissions from brick kilns

    NASA Astrophysics Data System (ADS)

    Rajarathnam, Uma; Athalye, Vasudev; Ragavan, Santhosh; Maithel, Sameer; Lalchandani, Dheeraj; Kumar, Sonal; Baum, Ellen; Weyant, Cheryl; Bond, Tami

    2014-12-01

    India has more than 100,000 brick kilns producing around 250 billion bricks annually. Indian brick industry is often a small scale industry and third largest consumer of coal in the country. With the growing demand for building materials and characterised by lack of pollution control measures the brick industry has a potential to cause adverse effects on the environment. This paper presents assessment of five brick making technologies based on the measurements carried out at seventeen individual brick kilns. Emissions of PM, SO2, CO and CO2 were measured and these emissions were used to estimate the emission factors for comparing the emissions across different fuel or operating conditions. Estimated emission from brick kilns in South Asia are about 0.94 million tonnes of PM; 3.9 million tonnes of CO and 127 million tonnes of CO2 per year. Among various technologies that are widely used in India, Zig zag and vertical shaft brick kilns showed better performance in terms of emissions over the traditional fixed chimney Bull's trench kilns. This suggests that the replacement of traditional technologies with Zig zag, vertical shaft brick kilns or other cleaner kiln technologies will contribute towards improvements in the environmental performance of brick kiln industry in the country. Zig zag kilns appear to be the logical replacement because of low capital investment, easy integration with the existing production process, and the possibility of retrofitting fixed chimney Bull's trench kilns into Zig zag firing.

  18. Distributions, profiles and formation mechanisms of polychlorinated naphthalenes in cement kilns co-processing municipal waste incinerator fly ash.

    PubMed

    Liu, Guorui; Zhan, Jiayu; Zhao, Yuyang; Li, Li; Jiang, Xiaoxu; Fu, Jianjie; Li, Chunping; Zheng, Minghui

    2016-07-01

    Co-processing municipal solid waste incinerator (MSWI) fly ash in cement kilns is challenging because the unintentional production of persistent organic pollutants (POPs) during the process is not well understood. The distributions, profiles and formation mechanisms of polychlorinated naphthalenes (PCNs) as new POPs covered under Stockholm Convention in two cement kilns co-processing MSWI fly ash were studied. The average concentrations of PCNs in stack gas samples were 710 ng m(-3). The PCN concentration in particle samples collected from different process stages in the cement kilns ranged from 1.1 to 84.7 ng g(-1). Three process sites including suspension pre-heater boiler, humidifier tower, and the kiln back-end bag filter were identified to be the major formation sites of PCNs in cement kilns co-processing MSWI fly ash. The PCN distribution patterns were similar to that of polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs), which indicates the possibility for simultaneous control of PCNs and PCDD/Fs in cement kilns co-processing fly ash. Chlorination was suggested to be an important formation mechanism of PCNs, and chlorination pathways of PCN congeners are proposed based on the congener profiles. Thermodynamic calculations, including relative thermal energies (ΔE) and standard free energy of formation (ΔG), and the charge densities of the carbon atoms in PCN supported the proposed chlorination mechanisms for PCN formation. The results presented in this study might provide helpful information for developing techniques and strategies to control PCN emissions during cement kilns co-processing MSWI fly ash.

  19. Experimental Evaluation of Waste Tires Utilization in Cement Kilns.

    PubMed

    Giugliano, Michèle; Cernuschi, Stefano; Ghezzi, Umberto; Grosso, Mario

    1999-12-01

    The present work outlines the main results of a full-scale study conducted on the utilization of waste tires as auxiliary fuel in cement production. Experimental tests were conducted for determining the influence of shredded tires on combustion conditions, emissions produced, and the characteristics of clinker obtained, for feeding ratios over 35% in terms of total heat input. The addition of tire chips did not lead to any appreciable modification in either the whole process or the quality of clinker produced; gaseous emissions were mostly unaffected, with significant improvements related to the reductions obtained in nitrogen and sulfur oxides concentrations. Experimental findings from tests conducted with tire chips exposed to kiln combustion flue gases compare favorably with the typical burnout times derived from theoretical approaches. These experimental data and calculations to estimate particle trajectories beyond the injection point, through proper theoretical analysis of the kinetic behavior, result in important indications for the shredding operation and for optimum injection modes.

  20. [Comparison of fixation effects of heavy metals between cement rotary kiln co-processing and cement solidification/stabilization].

    PubMed

    Zhang, Jun-li; Liu, Jian-guo; Li, Cheng; Jin, Yi-ying; Nie, Yong-feng

    2008-04-01

    Both cement rotary kiln co-processing hazardous wastes and cement solidification/stabilization could dispose heavy metals by fixation. Different fixation mechanisms lead to different fixation effects. The same amount of heavy metal compounds containing As, Cd, Cr, Cu, Pb, Zn were treated by the two kinds of fixation technologies. GB leaching test, TCLP tests and sequential extraction procedures were employed to compare the fixation effects of two fixation technologies. The leached concentration and chemical species distribution of heavy metals in two grounded mortar samples were analyzed and the fixation effects of two kinds of technologies to different heavy metals were compared. The results show the fixation effect of cement rotary kiln co-processing technology is better than cement solidification/stabilization technology to As, Pb, Zn. Calcinations in cement rotary kiln and then hydration help As, Pb, Zn contained in hazardous wastes transform to more steady chemical species and effectively dispose these heavy metals compounds. Cr3+ is liable to be converted to much more toxic and more mobile Cr6+ state in cement rotary kiln. And so Cr wastes are more fit for treatment by cement solidification/stabilization technology. The work could provide a basis when choosing disposal technologies for different heavy metals and be helpful to improve the application and development of cement rotary kiln co-processing hazardous wastes.

  1. THE FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A VENTURI/PACKED COLUMN SCRUBBER - VOLUME II: APPENDICES

    EPA Science Inventory

    A 5-week series of pilot-scale incineration tests, employing a synthetic waste feed, was performed at the U.S. Environmental Protection Agency's Incineration Research Facility to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with a venturi scrubber/p...

  2. 40 CFR 63.1345 - Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 12 2012-07-01 2011-07-01 true Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers... for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

  3. 40 CFR 63.1345 - Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 11 2011-07-01 2011-07-01 false Emissions limits for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers... for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

  4. 40 CFR 63.1348 - Standards for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw... Industry Emission Standards and Operating Limits § 63.1348 Standards for affected sources other than kilns; in-line kiln/raw mills; clinker coolers; new and reconstructed raw material dryers; and raw...

  5. Rotary kiln incineration III. An in depth study-kiln exit/afterburner/stack train and kiln exit pattern factor measurements during liquid CCl sub 4 processing

    SciTech Connect

    Cundy, V.A.; Lester, T.W.; Sterling, A.M.; Montestru, A.N.; Morse, J.S.; Leger, C.B.; Acharya, Sumanta )

    1989-07-01

    Temperature and stable species concentration data are presents for various locations within a full-scale rotary kiln incinerator firing natural gas/carbon tetrachloride/air. The data are being collected as part of a cooperative program involving university, industry and government participation. The overall goal of the program is to develop a more sophisticated understanding of and a predictive capability for rotary kiln and afterburner performance as influenced by basic design and operational parameters. Non-uniformities in stable species and temperature exist for this particular kiln, at the kiln exit, under certain operating conditions. Flow perturbations from within the kiln were found to persist into the afterburner, but not into the stack. High destruction and removal efficiencies (DRE's) were achieved under the operating conditions of these tests through adequate secondary combustion processing.

  6. Dynamic modelling of a dehumidifier wood drying kiln

    SciTech Connect

    Sun, Z.F.; Carrington, C.G.

    1999-04-01

    For the optimum design and operating information of heat pump dehumidifier wood drying kilns, a comprehensive kiln model has been developed, which solves the fundamental balance equations for the whole system. The model is suitable for analyzing the influence of design and control variables on the performance of the system as a whole. To illustrate the application of the model, the operation of a dehumidifier wood drying kiln has been analyzed under typical operating conditions and kiln controls. The drying performance has been discussed in detail.

  7. Emissions of air toxics from a simulated charcoal kiln. Final report, October 1997--September 1998

    SciTech Connect

    Lemieux, P.M.

    1999-06-01

    The report gives results of experiments in a laboratory-scale charcoal kiln simulator to evaluate emissions of hazardous air pollutants from the production of charcoal in Missouri-type kilns. Fixed combustion gases were measured using continuous monitors. In addition, other pollutants, including methanol, volatile organic compounds, semivolatile organic compounds, and particle emission rates and size distributions were measured using various techniques. Emissions of all pollutants are reported in units of grams emitted per unit mass of initial wood converted to charcoal. Two burn conditions--slow and fast--were examined. High levels of methanol, benzene, and fine particulate were emitted in all tests. The estimated emissions from the fast burn conditions were significantly higher than those from the slow burn conditions.

  8. Emissions of air toxics from the production of charcoal in a simulated Missouri charcoal kiln

    SciTech Connect

    Lemieux, P.M.; Kariher, P.H.; Fairless, B.J.; Tapp, J.A.

    1998-11-01

    The paper gives results of experiments in a laboratory-scale charcoal kiln simulator to evaluate emissions of hazardous air pollutant from the production of charcoal in Missouri-type kilns. Fixed combustion gases were measured using continuous monitors. In addition, other pollutants, including methanol, volatile organic compounds, semivolatile organic compounds, and particle emission rates and size distributions were measured using various techniques. Emissions of all pollutants are reported in grams emitted per unit mass of initial wood converted to charcoal. Two burn conditions--slow and fast burn--were examined. High levels of methanol, benzene, and fine particulate were emitted from all tests. The estimated emissions from the fast burn conditions were significantly higher than those from the slow burn conditions.

  9. 40 CFR 63.1343 - Standards for kilns and in-line kiln/raw mills.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... limits are on a dry basis, corrected to 7 percent oxygen. All total hydrocarbon (THC) emission limits are... hydrocarbon (THC) limits and monthly for the 50 ppmv THC limit. (b) Existing kilns located at major sources... particulate matter control device is 204 °C (400 °F) or less. (4) Contain total hydrocarbons (THC), from...

  10. 46. KILN ROOM, SOUTH END OF THE EAST WING. UNIQUE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    46. KILN ROOM, SOUTH END OF THE EAST WING. UNIQUE ELECTRIC KILN, MANUFACTURED BY HED INDUSTRIES IN RINGOES, NJ. INSTALLED IN 1986. USED FOR GLAZE FIRING. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  11. 38. DETAIL OF VIVIANNA WORKS ROTARY KILN FIREBOX ABOVE CHANNEL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. DETAIL OF VIVIANNA WORKS ROTARY KILN FIREBOX ABOVE CHANNEL FOR THE REMOVAL OF TAILINGS FROM THE ROTARY KILN LOOKING NORTHWEST. CONDENSER TO THE RIGHT, TWO STORY OFFICE AND STOREROOM STRUCTURE BEHIND. - Mariscal Quicksilver Mine & Reduction Works, Terlingua, Brewster County, TX

  12. 9. Rear of northern kiln group, looking northeast. Although not ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. Rear of northern kiln group, looking northeast. Although not visible from this distance, the Viola Mine was located in the mountain range in the background. - Warren King Charcoal Kilns, 5 miles west of Idaho Highway 28, Targhee National Forest, Leadore, Lemhi County, ID

  13. New emission controls for Missouri batch-type charcoal kilns

    SciTech Connect

    Yronwode, P.; Graf, W.J.

    1999-07-01

    Charcoal kilns have been exempted from air emission regulation in the state of Missouri. Today, 80% of US charcoal production takes place in Missouri. As a result of a petition filed by people in the area around an installation in southern Missouri, the US Environmental Protection Agency (EPA) set up air monitors and measured ambient air levels at that charcoal manufacturing installation. These monitors yielded the highest particulate matter less than 10 micron (PM{sub 10}) levels ever recorded in the state. Earlier stack testing at another charcoal manufacturing installation indicated that toxics and carcinogens are present in charcoal kiln air emissions. A Charcoal Kiln Workgroup was formed to determine the Best Available Control Technology (BACT) for charcoal kilns and to draft a charcoal kiln rule that requires BACT. The BACT report determined that afterburners were suitable for controlling emissions from batch-type charcoal kilns. In addition, the charcoal industry supported incorporating the BACT limits and requirements into an enforceable state rule and submitting this rule to the EPA for federal approval. A consent agreement between the EPA and three major charcoal companies was signed with provisions to install, operate, and maintain emission control devices on charcoal kilns. This agreement was to settle complaints alleging that the three major charcoal producers had failed to report toxic air emissions to federal and state regulators. The agreement provided that industry would install control devices on a set schedule with some charcoal kilns being shut down.

  14. Community Geothermal Technology Program: Experimental lumber drying kiln. Final report

    SciTech Connect

    Leaman, D.; Irwin, B.

    1989-10-01

    Goals were to demonstrate feasibility of using the geothermal waste effluent from the HGP-A well as a heat source for a kiln operation to dry hardwoods, develop drying schedules, and develop automatic systems to monitor/control the geothermally heated lumber dry kiln systems. The feasibility was demonstrated. Lumber was dried in periods of 2 to 6 weeks in the kiln, compared to 18 months air drying and 6--8 weeks using a dehumidified chamber. Larger, plate-type heat exchangers between the primary fluid and water circulation systems may enable the kiln to reach the planned temperatures (180--185 F). However, the King Koa partnership cannot any longer pursue the concept of geothermal lumber kilns.

  15. Modeling of pulverized coal combustion in cement rotary kiln

    SciTech Connect

    Shijie Wang; Jidong Lu; Weijie Li; Jie Li; Zhijuan Hu

    2006-12-15

    In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rotary kiln were obtained by numerical simulation of a 3000 t/d rotary kiln with a four-channel burner. The predicted results indicated that the improved model accounts for the thermal enthalpy of the clinker formation process and can give more insight (such as fluid flow, temperature, etc,) from within the cement rotary kiln, which is a benefit to better understanding of combustion behavior and an improvement of burner and rotary kiln technology. 25 refs., 12 figs., 5 tabs.

  16. Variations and factors that influence the formation of polychlorinated naphthalenes in cement kilns co-processing solid waste.

    PubMed

    Jin, Rong; Zhan, Jiayu; Liu, Guorui; Zhao, Yuyang; Zheng, Minghui

    2016-09-05

    Pilot studies of unintentionally produced pollutants should be performed before waste being co-processed in cement kilns. Polychlorinated naphthalene (PCN) formation and emission from cement kilns co-processing sorted municipal solid waste, sewage sludge, and waste acid, however, have not previously been studied. Here, PCNs were analyzed in stack gas samples and solid samples from different stages of three cement production runs. PCN destruction efficiencies were higher when waste was co-processed (93.1% and 88.7% in two tests) than when waste was not co-processed (39.1%), so co-processing waste would not increase PCN outputs. The PCN concentrations were higher in particle samples from the C1 preheater and stages at back end of kiln than in particle samples from other stages, suggesting that cyclone preheater and back end of kiln should be focused for controlling PCN emissions. Besides that, based on the variation of PCN concentrations and corresponding operating conditions in different stages, the temperature, feeding materials, and chlorine content were suggested as the main factors influencing PCN formation. The PCN homologue and congener profiles suggested chlorination and dechlorination were the main PCN formation and decomposition pathways, and congeners CN-23, CN-46, and CN-59 appear to be appropriate indicators of PCNs emitted from coal-burning sources.

  17. Reliability Optimization of Radial Distribution Systems Employing Differential Evolution and Bare Bones Particle Swarm Optimization

    NASA Astrophysics Data System (ADS)

    Kela, K. B.; Arya, L. D.

    2014-09-01

    This paper describes a methodology for determination of optimum failure rate and repair time for each section of a radial distribution system. An objective function in terms of reliability indices and their target values is selected. These indices depend mainly on failure rate and repair time of a section present in a distribution network. A cost is associated with the modification of failure rate and repair time. Hence the objective function is optimized subject to failure rate and repair time of each section of the distribution network considering the total budget allocated to achieve the task. The problem has been solved using differential evolution and bare bones particle swarm optimization. The algorithm has been implemented on a sample radial distribution system.

  18. PIV/PLIF experiments of jet mixing in a model of a rotary kiln

    NASA Astrophysics Data System (ADS)

    Larsson, I. A. Sofia; Johansson, Simon P. A.; Lundström, T. Staffan; Marjavaara, B. Daniel

    2015-05-01

    The jet mixing in a downscaled, isothermal model of a rotary kiln is investigated experimentally through simultaneous particle image velocimetry and planar laser-induced fluorescence measurements. The kiln is modeled as a cylinder with three inlets in one end, two semicircular-shaped inlets for what is called the secondary fluid divided by a wall in between, called the back plate, where the burner nozzle is located. The scaling of the burner nozzle between real kiln and model and the corresponding jet flow through it is determined by the Craya-Curtet parameter. Three momentum flux ratios of the secondary fluid are investigated, and the interaction with the burner jet is scrutinized. It is found that the burner jet characteristics, its mixing with the secondary fluid and the resulting flow field surrounding the jet are dependent on the momentum flux ratio. A particular result is that stable shear layers give a more even mixing as compared to a case with shear layers subjected to a more prominent vortex shedding.

  19. Device for charging combustible solids to rotary kilns

    SciTech Connect

    Tutt, J.R.; Benoit, M.R.

    1993-07-13

    An apparatus is described for controlling the entry of combustible solids through a port formed in a wall of a rotary kiln cylinder of an operating cement kiln at a location between an upper end and a lower fired end thereof, the kiln containing hot mineral material for combustion of said solids in contact with said mineral material, the apparatus comprising a port closure assembly comprising a closure movable between a port-opened and port-closed position and means for moving the closure between the port-opened and port-closed positions at predetermined times during rotation of the kiln cylinder; a staging assembly including a support projecting therefrom in alignment with the port for supporting combustible solids; and, a transfer assembly mounted on the kiln wall at a point in alignment with the port for transferring combustible solids from the staging assembly to the port, said transfer assembly being formed to include at least one slot sized to allow said support to pass there through so that combustible solids on the support are lifted from said support by the kiln wall mounted transfer assembly as it sweeps past the staging assembly during kiln cylinder rotation.

  20. Real-time simulation of solar kiln drying of timber

    SciTech Connect

    Steinmann, D.E.

    1995-05-01

    A major problem in optimizing solar kiln design and control is that natural weather conditions cannot be repeated in consecutive drying runs. All results are, therefore, dependent on the specific weather conditions during any given drying run. The construction and testing of a simulation system to overcome this problem of non-repeatability is described. The simulation system consists of a miniature solar kiln placed inside a climatic chamber and was used to dry pieces of wood using a selected weather sequence which was repeated for consecutive drying runs. The performance of the simulation system was compared to that of the solar kiln and very good agreement was achieved. 5 refs., 8 figs.

  1. Coal fueled ported kiln direct reduction process in Norway

    SciTech Connect

    Rierson, D.W.

    1994-12-31

    Allis Mineral Systems (AMS), formerly the minerals processing group at Allis-Chalmers Corporation, developed a ported kiln process in the 1960`s specifically for the direct reduction of iron ore. The process is called ACCAR. This ported kiln technology has more recently been coupled with AMS` GRATE-KILN System for iron oxide pelletizing into the GRATE-CAR Process, for minerals reduction. The GRATE-CAR Process can handle a fine grained ore concentrate through the steps of agglomeration, induration and reduction in a single production line.

  2. 57. ORIGINAL TILE PRESS AND EXPERIMENTAL DENTAL KILN, SECOND FLOOR, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    57. ORIGINAL TILE PRESS AND EXPERIMENTAL DENTAL KILN, SECOND FLOOR, NORTH WING, HENRY MERCER USED THE KILN FOR HIS EARLIEST GLAZE TESTS. THE PRESS WAS DESIGNED TO BE USED WITH METAL CASED MOLDS. SINCE ONLY THE EARLIEST TILE DESIGNS ARE IN METAL CASES. THIS TECHNIQUE WAS PROBABLY DISCONTINUED. THIS PRESS WAS, THEREFORE, PROBABLY NOT USED EXTENSIVELY AT THIS SITE. THE UPPER PART OF GLAZE KILN No. 2 IS AT THE LEFT REAR. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  3. 25. INTERIOR OF GLAZE KILN NO. 2, SHOWING HOW SAGGERS ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    25. INTERIOR OF GLAZE KILN NO. 2, SHOWING HOW SAGGERS AND LOOSE QUARRY TILES WERE STACKED. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  4. A commercially viable solar wood drying kiln system

    SciTech Connect

    Vore, J.B. de; Denny, G.S.; Harper, T.S.

    1999-01-01

    The purpose of the study was to create a totally passive solar wood drying kiln that would dry lumber to 9% moisture content in a reasonable amount of time. A series of modifications led to a kiln design that dried freshly-cut lumber to 8% in a 29-day period with no case hardening or cracking. Air speed, internal and external temperatures and relative humidity levels were measured at 5-minute intervals. The average temperature inside the kiln was 12% higher with relative humidity levels 19% lower than outside the kiln. It is hypothesized that the daily cycles of heating and cooling permitted the interior moisture of the wood to reach the surface through diffusion, thus lessening stress and speeding drying of the lumber.

  5. 24. Photocopy of photograph. VIEW OF CHARCOAL KILNS AND IRON ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    24. Photocopy of photograph. VIEW OF CHARCOAL KILNS AND IRON PLANT FROM SOUTH END OF BEACH, probably 1901. (From the Robert Teagle Private Collection, Port Townsend, WA) - Irondale Iron & Steel Plant, Port Townsend, Jefferson County, WA

  6. VIEW OF TUNNEL TO MLT BUILDING UNDER LIME KILNS. CONVEYOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF TUNNEL TO MLT BUILDING UNDER LIME KILNS. CONVEYOR MOVES HOT STONE TO MLT'S. THIS IS THE DRIVE END OF CONVEYOR BELT. - Solvay Process Company, Milk of Lime Towers Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  7. VIEW OF TUNNEL TO MLT BUILDING UNDER LIME KILNS, CONVEYOR ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF TUNNEL TO MLT BUILDING UNDER LIME KILNS, CONVEYOR MOVES HOT STONE TO MLT'S (CONVEYOR ON RIGHT). - Solvay Process Company, Milk of Lime Towers Building, Between Willis & Milton Avenues, Solvay, Onondaga County, NY

  8. 51. UPPER CHAMBER OF BISCUIT KILN No. 4, FROM THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    51. UPPER CHAMBER OF BISCUIT KILN No. 4, FROM THE SECOND FLOOR. ALL BRICK KILNS AT THE MORAVIAN POTTERY AND TILE WORKS HAD TWO CHAMBERS. WARE WAS STACKED IN THE LOWER CHAMBERS FOR FIRING AND THE UPPER CHAMBERS PROVIDED ACCESS TO FLUES AND DAMPERS FROM THE SECOND FLOOR. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  9. 38. SLABROLLING ROOM, SHOWING BISCUIT KILN No. 4 IN THE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    38. SLAB-ROLLING ROOM, SHOWING BISCUIT KILN No. 4 IN THE CENTER BACKGROUND AND BISCUIT KILN No. 5 AT THE RIGHT. TILE PRESSES ARE THROUGH THE DOORWAY AT THE LEFT. NOTE THE AIR FILTER, INSTALLED IN 1986. HANGING IN THE CENTER OF THE ROOM. - Moravian Pottery & Tile Works, Southwest side of State Route 313 (Swamp Road), Northwest of East Court Street, Doylestown, Bucks County, PA

  10. Heat exchange apparatus and process for rotary kilns

    SciTech Connect

    De Beus, A.J.

    1987-06-30

    This patent describes a heat exchange apparatus for use in a rotary kiln, the heat exchange apparatus comprising: refractory means for transferring heat from an upper heated portion of a rotary kiln above a bed disposed in a lower portion to within the bed as the rotary kiln is rotated. The refractory means comprises: tubular refractory members; means for attaching the refractory means in a spaced apart relationship with an interior wall of the rotary kiln in order to cause the refractory means to pass through the bed with a portion of the bed passing under the refractory means. A portion of the bed passes over the refractory means in order to enhance heat transfer as the rotary kiln is rotated. The means for attaching the refractory means comprises rods supported by stanchions and tubular refractory member disposed on the rods; the means for attaching the refractory means and the refractory means is configured and operative for stirring the bed as the refractory means pass through the bed without significant lifting of the bed to the heated upper portions of the rotary kiln as the rotary kiln is rotated; and compressible refractory spacer means disposed between each tubular refractory member for accommodating heat expansion and compressible refractory sleeve means dispersed between the rods and the tubular refractory members for accommodating heat expansion of the rods. Compressible refractory sleeve means and tubular refractory member sized so that the tubular refractory members are tightly held against the tubular refractory spacer means when the rotary kiln is at operating temperatures in order to inhibit fracture of the tubular refractory member as they pass through the bed.

  11. Hazardous-waste incineration in a rotary kiln

    SciTech Connect

    Owens, W.D. Jr.

    1991-01-01

    A rotary-kiln simulator was used to develop a better understanding of how hazardous materials are removed from sorbent clays. Experimental results and associated numerical modeling on the combustion and desorption of toluene from a montmorillonite clay sorbent are presented. The purpose of these tests was to understand the mass and heat transfer characteristics of the material in a rotary kiln environment. The experiments were done in a batch mode, simulating a control volume of solids moving down the length of a full-scale rotary kiln, exchanging time for distance as the independent variable. Studies investigating the effect of oxygen concentration, charge size, rotational velocity, and kiln cavity temperature on the desorption rate were completed. Also, effects of water in the montmorillonite were examined. Two comprehensive models were developed to predict the thermal and mass desorption characteristics of the bed, respectively. Another series of studies in the rotary kiln simulator was focused on NO, formation from nitrogenous waste constituents. These tests were performed to simulate materials (plastics, nylons, dyes, and process waste) usually destroyed in hazardous-waste incinerators. Four surrogate wastes, Aniline, Pyridine, Malononitrile, and Ethylenediamine, were absorbed onto the montmorillonite clay sorbent. A detailed discussion regarding the design, construction and operation of the rotary-kiln simulator for research on the destruction of hazardous waste materials is presented in the Appendices. All facility calibration techniques and calculations in addition to data acquisition and reduction algorithms are also discussed there.

  12. Minimization of transient emissions from rotary-kiln incinerators, 1990

    SciTech Connect

    Lemieux, P.M.; Linak, W.P.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E.

    1990-01-01

    The paper discusses combining experimental results from a pilot-scale rotary kiln incinerator simulator with a theoretical model in order to explore the potential of minimizing transient emissions through changes in kiln rotation speed and temperature, steady state oxygen enrichment, and oxygen enrichment in a dynamic mode. Results indicate that transient organic emissions can indeed be minimized by changes in these kiln operating parameters but, because of the complex interactions of physical and chemical processes controlling emissions, the appropriate abatement procedures must be implemented carefully. Transient emissions of organics occur from rotary kiln incinerators when drums containing liquid wastes bound on sorbents are introduced in batches. Physical processes controlling the release of waste from the sorbent material are greatly affected by the rotation speed and temperature of the kiln. Local partial pressure of oxygen influences the rate of oxidation of the puff formed inside the kiln. These physical and chemical phenomena can be used to control transient emissions by oxygen enrichment, where it is done in either a steady or a dynamic mode.

  13. On-Line Oxidation of Volatile Organic Compounds Generated by Sawmill Wood Kilns

    SciTech Connect

    R. Arun Kumar; Dr. Philip Steele; W. Dean Patterson

    2007-03-29

    The primary purpose of this project was to evaluate the effectiveness of the use of hydrogen peroxide in combination with ultra-violet (UV) light for the reduction in the amount of volatile organic compounds (VOC’s) released into the environment during wood drying in sawmill kilns. As originally envisioned the scope of work included the optimization of reaction parameters i.e. pH, peroxide concentration, UV light intensity that would lead to successful destruction of VOC’s. The second phase involved development of a prototypical reactor that could be taken to a sawmill kiln for demonstration of treatment of a slipstream. However, after some of our initial experiments, we were forced to limit ourselves to more modest testing and development. During the project period we designed and constructed a small-scale reactor that was connected to the off-gas from a small wood drying kiln located at the Forest Products Lab at Mississippi State University. We ran a number of tests where we varied the process parameters (peroxide concentration, pH and UV light intensity) with no reasonable amount of VOC destruction. We employed a number of ways to atomize the peroxide into the kiln off-gas including using Laskin nozzles to see if that would improve the VOC reduction, but it was to no avail. The next option we explored was to try and utilize Fenton’s Reagent to see if that would be an effective tool in our treatment process. Initial measurements appeared to provide very good VOC reductions, but upon more detailed investigation it appeared that the oxygen being generated in the Fenton’s reaction was artificially reducing the VOC concentration coming from the treatment chamber. The last treatment system that we tried to use was the treatment of the kiln off-gas with hydrogen peroxide injection in the vapor phase. We were not able to achieve any success with this treatment method either. It appears from our tests that there doesn’t seem to be an easy way of obtaining VOC

  14. Zink rotary kiln seal: Cam followers. Revision 1

    SciTech Connect

    Fisher, D.L.

    1994-12-09

    The CIF will treat hazardous and mixed low-level radioactive waste in a rotary kiln and secondary combustion chamber. A high efficiency air pollution control system follows the secondary chamber. The rotary kiln is designed with a gas seal at each end of its rotating barrel which provides a barrier between the interior of the kiln and outside air. The internal pressure of the rotary kiln will be maintained below atmospheric pressure, so exterior air passing the seals is forced into the kiln`s interior. Positive pressure may be applied in the seal labyrinth, adding a barrier to flow. Both CIF seals will be covered entirely with exhaust hoods, drawing air over the outside of the seal and into a HEPA filtered exhaust system. Cam follower misalignment on a John Zink rotary kiln seal caused damage to the seal`s rotor. The misalignment was quantified, corrected, and checked to verify straightness. The primary purpose of the correction was to allow seal testing 1 to continue, but the information is applicable to the Consolidated Incineration Facility (CIF) since two large seals of similar design will be installed there. Cam follower straightness was off as much as 3.5{degrees}, causing followers to run untrue on the rotor. High contact forces resulted, removing flakes of metal from the rotor surface. The misalignment caused weight bearing followers on one side of the seal to back out of their threaded mounts. The root cause was poor machining of the follower mounting holes. Correction was accomplished by relieving the holes and installing machined spacers and retaining nuts. Cam followers on the CIF`s Zink seals should be inspected for straightness before the seals are installed.

  15. The Effect of Kiln Drying on the Strength of Airplane Woods

    NASA Technical Reports Server (NTRS)

    Wilson, T R C

    1920-01-01

    This report is a very complete treatise on the comparative strength of air and kiln dried wood. The series of tests includes 26 species of wood, approximately 100 kiln runs, and over 10,000 mechanical tests.

  16. Coal desulfurization in a rotary kiln combustor

    SciTech Connect

    Cobb, J.T. Jr.

    1991-08-29

    Several issues that could have an impact on the capability to burn anthracite culm in a rotary bed boiler were identified; specifically, questions were raised concerning the specifications of the anthracite culm itself and some relating to the equipment. The anthracite culm delivered was wet, (with more than 10 percent moisture), and coarser than feed material for fluidized boilers. It was felt that using finer fuel, ensuring that it is largely dry, would aid the combustion of anthracite culm. It also appeared that if provisions were made for more efficient internal and external recycle of ash, this would also enhance the combustion of this fuel. Accordingly, the decision was made to conduct an additional campaign of tests that would incorporate these changes. The tests, conducted on July 15 and 16, 1991, involved an anthracite culm that was, in fact, obtained from a fluidized bed a heating value of 3,000 Btu/lb and came with a top size of 1/4-inch. Despite these changes, sustained combustion could not be achieved without the use of large quantities of supplemental fuel. Based on these tests, we tend to conclude that the rotary kiln is ill suited for the combustion of hard-to-burn, low-grade solid fuels like anthracite culm.

  17. Effects of charcoal kiln saunas (Jjimjilbang) on psychological states.

    PubMed

    Hayasaka, Shinya; Nakamura, Yosikazu; Kajii, Eiji; Ide, Masahiro; Shibata, Yosuke; Noda, Tatsuya; Murata, Chiyoe; Nagata, Katsutaro; Ojima, Toshiyuki

    2008-05-01

    This uncontrolled intervention study explored the effects of sauna bathing utilizing residual heat from charcoal kilns (charcoal kiln saunas) on psychological states. Forty-five volunteers (24 males and 21 females; mean age 51.9 years (S.D. 15.7) visiting a bamboo charcoal kiln in Japan participated in the study. They completed a shortened version of the Profile of Mood States (POMS) and State-Trait Anxiety Inventory (STAI) before and after charcoal kiln sauna bathing in order to determine mood and anxiety states. Six factors relating to mood were measured using the POMS: Tension-Anxiety, Depression-Dejection, Anger-Hostility, Vigor, Fatigue, and Confusion. The two anxiety concepts of state anxiety and trait anxiety were also measured. Changes in psychological states before and after sauna bathing were then determined. All mood scales and both manifest anxiety measures were improved after sauna bathing. Charcoal kiln sauna bathing appears to improve mood and decrease anxiety. It is a limitation of this study that this was a descriptive prospective and an uncontrolled intervention study. Further investigation of the improvement of trait anxiety is required.

  18. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL... Waste Combustors Replacement Emissions Standards and Operating Limits for Incinerators, Cement Kilns... burning cement kilns? (a) Emission and hazardous waste feed limits for existing sources. You must...

  19. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL... Waste Combustors Replacement Emissions Standards and Operating Limits for Incinerators, Cement Kilns... burning cement kilns? (a) Emission and hazardous waste feed limits for existing sources. You must...

  20. Modeling of rotary cement kilns: Applications to reduction in energy consumption

    SciTech Connect

    Mujumdar, K.S.; Arora, A.; Ranade, V.V.

    2006-03-29

    We discuss and evaluate possible ways of reducing energy consumption in rotary cement kilns. A comprehensive one-dimensional model was developed to simulate complex processes occurring in rotary cement kilns. A modeling strategy comprising three submodels, viz. a model for simulating the variation of bed height in the kiln, a model for simulating reactions and heat transfer in the bed region, and a model for simulating coal combustion and heat transfer in the freeboard region, was developed. Melting and formation of coating within the kiln were accounted for. Combustion of coal in the freeboard region was modeled by accounting for devolatilization, finite-rate gas-phase combustion, and char reaction. The simulated results were validated with the available data from three industrial kilns. The model was then used to understand the influence of various design and operating parameters on kiln performance. Several ways of reducing energy consumption in kilns were then computationally investigated. The model was also used to propose and to evaluate a practical solution of using a secondary shell to reduce energy consumption in rotary cement kilns. Simulation results indicate that varying kiln operating variables, viz. solid flow rate or RPM, can result only in small changes in kiln energetics. Use of a secondary shell over the kiln and energy recovery by passing air through the annular gap between the two appears to be a promising way to achieve significant energy savings. The developed model and the presented results will be useful for enhancing the performance of rotary cement kilns.

  1. Validation of a dynamic model for a dehumidifier wood drying kiln

    SciTech Connect

    Sun, Z.F.; Carrington, C.G.; Bannister, P.

    1999-04-01

    The validation of a dehumidifier wood drying kiln model established previously has been conducted by using the performance data for a commercial scale kiln. The good agreement between the modelled and measured performance results shows that the model can be used for the design and analysis of dehumidifier wood drying kilns.

  2. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL... Waste Combustors Replacement Emissions Standards and Operating Limits for Incinerators, Cement Kilns... burning cement kilns? (a) Emission and hazardous waste feed limits for existing sources. You must...

  3. A case study of air enrichment in rotary kiln incineration

    SciTech Connect

    Melo, G.F.; Lacava, P.T.; Carvalho, J.A. Jr.

    1998-07-01

    This paper presents a case study of air enrichment in an industrial rotary kiln type incineration unit. The study is based on mass and energy balances, considering the combustion reaction of a mixture composed by the residue and the auxiliary fuel with air enriched with oxygen. The steps are shown for the primary chamber (rotary kiln) and secondary chamber (afterburner). The residence times in the primary and secondary chamber are 2.0 and 3.2 sec, respectively. The pressure is atmospheric in both chambers. Based on constant chamber gas residence time and gas temperature, it is shown that the residue input rates can be increased by one order of magnitude as air is substituted by pure oxygen. As the residue consumption rate in the rotary kiln is also dependent on residue physical characteristics (mainly size), the study was also carried out for different percentages of oxygen in the oxidizer gas.

  4. 40 CFR 63.1204 - What are the standards for hazardous waste burning cement kilns that are effective until...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... waste burning cement kilns that are effective until compliance with the standards under § 63.1220? 63... Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1204 What are the standards for hazardous waste burning cement kilns that are effective until...

  5. 40 CFR 63.1204 - What are the standards for hazardous waste burning cement kilns that are effective until...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... waste burning cement kilns that are effective until compliance with the standards under § 63.1220? 63... Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1204 What are the standards for hazardous waste burning cement kilns that are effective until compliance with the...

  6. 40 CFR 63.1204 - What are the standards for hazardous waste burning cement kilns that are effective until...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... waste burning cement kilns that are effective until compliance with the standards under § 63.1220? 63... Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1204 What are the standards for hazardous waste burning cement kilns that are effective until compliance with the...

  7. 40 CFR 63.1204 - What are the standards for hazardous waste burning cement kilns that are effective until...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... waste burning cement kilns that are effective until compliance with the standards under § 63.1220? 63... Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1204 What are the standards for hazardous waste burning cement kilns that are effective until...

  8. 40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... waste burning lightweight aggregate kilns that are effective until compliance with the standards under Â... Emissions Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1205 What are the standards for hazardous waste burning lightweight aggregate kilns that...

  9. 40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... Kilns, and Lightweight Aggregate Kilns § 63.1221 What are the replacement standards for hazardous waste burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for existing...

  10. 40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... Kilns, and Lightweight Aggregate Kilns § 63.1221 What are the replacement standards for hazardous waste burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for existing...

  11. 40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... waste burning lightweight aggregate kilns that are effective until compliance with the standards under Â... Emissions Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1205 What are the standards for hazardous waste burning lightweight aggregate kilns that...

  12. 40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... waste burning lightweight aggregate kilns that are effective until compliance with the standards under Â... Emissions Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1205 What are the standards for hazardous waste burning lightweight aggregate kilns that...

  13. 40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... hazardous waste burning lightweight aggregate kilns? 63.1221 Section 63.1221 Protection of Environment... Kilns, and Lightweight Aggregate Kilns § 63.1221 What are the replacement standards for hazardous waste burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits for existing...

  14. 40 CFR 63.1204 - What are the standards for hazardous waste burning cement kilns that are effective until...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... waste burning cement kilns that are effective until compliance with the standards under § 63.1220? 63... Operating Limits for Incinerators, Cement Kilns, and Lightweight Aggregate Kilns § 63.1204 What are the standards for hazardous waste burning cement kilns that are effective until compliance with the...

  15. Modeling of heat transfer in a rotary kiln thermal desorder for removal of petroleum from soils

    SciTech Connect

    Chern, Hsien-Tsung; Krasnoperov, L.V.; Bozzelli, J.W.

    1996-10-01

    A continuous feed rotary kiln thermal desorber was designed and constructed to study the heat transfer in removal of petroleum hydrocarbons from contaminated soils. A mathematical model of heat transfer that correlates temperatures of gas, soil, and kiln wall will purge gas flow, soil feed rate, kiln rotation speed and soil residence time in the kiln desorber is developed. A fourth order Runge-Kutta method was used to numerically integrate the heat transfer process along the kiln length and to calculate the temperature profiles. Comparison of predicted and measured gas and soil temperature profile is presented.

  16. Formation, release and control of dioxins in cement kilns.

    PubMed

    Karstensen, Kåre Helge

    2008-01-01

    Co-processing of hazardous wastes in cement kilns have for decades been thought to cause increased emissions of PCDD/PCDFs--a perception that has been evaluated in this study. Hundreds of PCDD/PCDF measurements conducted by the cement industry and others in the last few years, on emissions and solid materials, as well as recent test burns with hazardous wastes in developing countries do not support this perception. Newer data has been compared with older literature data and shows in particular that many emission factors have to be reconsidered. Early emission factors for cement kilns co-processing hazardous waste, which are still used in inventories, are shown to be too high compared with actual measurements. Less than 10 years ago it was believed that the cement industry was the main contributor of PCDD/PCDFs to air; data collected in this study indicates however that the industry contributes with less than 1% of total emissions to air. The Stockholm Convention on POPs presently ratified by 144 parties, classifies cement kilns co-processing hazardous waste as a source category having the potential for comparatively high formation and release of PCDD/PCDFs. This classification is based on early investigations from the 1980s and 1990s where kilns co-processing hazardous waste had higher emissions compared to those that did not burn hazardous waste. However, the testing of these kilns was often done under worst case scenario conditions known to favour PCDD/PCDF formation. More than 2000 PCDD/PCDF cement kiln measurements have been evaluated in this study, representing most production technologies and waste feeding scenarios. They generally indicate that most modern cement kilns co-processing waste today can meet an emission level of 0.1ngI-TEQ/m(3), when well managed and operated. In these cases, proper and responsible use of waste including organic hazardous waste to replace parts of the fossil fuel does not seem to increase formation of PCDD/PCDFs. Modern preheater

  17. DNA-protein crosslinks as a biomarker of exposure to solar radiation: a preliminary study in brick-kiln workers.

    PubMed

    Budhwar, Roli; Bihari, Vipin; Mathur, Neeraj; Srivastava, Ak; Kumar, Sushil

    2003-01-01

    In India, fired clay bricks are produced in small-scale factories. There are 60, 000 active brick kilns, providing employment to nearly 12 million people in different suboccupations. This industry is largely non-mechanized and operates from November to June. Almost all the workers are exposed to direct sunlight for 8-10 h a day. Cellular DNA-protein crosslinks (DPCs) are the biologically active nucleoprotein complexes formed between DNA and proteins. Ultraviolet light and gamma-rays, and other suspected carcinogens in humans, induce DPC formation in blood cells. DPCs have therefore been identified as a biomarker for monitoring exposure to these hazardous agents. Here we report steady-state levels of DPCs in human peripheral lymphocytes from 46 brick-kiln workers exposed occupationally for 8-10 h a day to solar radiation in brickfields and 25 unexposed controls. A significant increase (p <0.05) in DPC content and DPC coefficients in peripheral lymphocytes was observed in the brick-kiln workers compared with the controls. The data suggest that the DPC content of lymphocytes could be a possible biomarker of exposure to solar radiation. However, further work is necessary to confirm this.

  18. Combustion modeling and performance evaluation in a full-scale rotary kiln incinerator.

    PubMed

    Chen, K S; Hsu, W T; Lin, Y C; Ho, Y T; Wu, C H

    2001-06-01

    This work summarizes the results of numerical investigations and in situ measurements for turbulent combustion in a full-scale rotary kiln incinerator (RKI). The three-dimensional (3D) governing equations for mass, momentum, energy, and species, together with the kappa - epsilon turbulence model, are formulated and solved using a finite volume method. Volatile gases from solid waste were simulated by gaseous CH4 distributed nonuniformly along the kiln bed. The combustion process was considered to be a two-step stoichiometric reaction for primary air mixed with CH4 gas in the combustion chamber. The mixing-controlled eddy-dissipation model (EDM) was employed to predict the conversion rates of CH4, O2, CO2, and CO. The results of the prediction show that reverse flows occur near the entrance of the first combustion chamber (FCC) and the turning point at the entrance to the second combustion chamber (SCC). Temperature and species are nonuniform and are vertically stratified. Meanwhile, additional mixing in the SCC enhances postflame oxidation. A combustion efficiency of up to 99.96% can be achieved at approximately 150% excess air and 20-30% secondary air. Reasonable agreement is achieved between numerical predictions and in situ measurements.

  19. PREPP (Process Experimental Pilot Plant) rotary kiln seals: Problem and resolution

    SciTech Connect

    Drexler, R.L. )

    1990-01-01

    The Process Experimental Pilot Plant (PREPP) is a facility designed to demonstrate processing of low level chemical and transuranic hazardous waste. The plant includes equipment for handling the incoming waste containers, shredding, incineration and cooling the waste, grouting the residue and scrubbing and filtration of the off gas. The process incinerator is a rotary kiln approximately 8-{1/2} ft diameter and 25 ft long with a rotary seal assembly at each end. Each seal assembly consists of a primary, secondary and tertiary seal, with a positive air pressure between primary and secondary seals to prevent out-leakage from the kiln. The kiln operates at 0.5 inch water negative pressure. From the very outset the kiln seals exhibited excessive drag which taxed the kiln drive capacity and excessive in-leakage which limited kiln temperature. An engineering evaluation concluded that the original seals supplied by the kiln vendor could not accommodate expansion and centerline shift of the kiln resulting from heatup of the kiln and its support system. A totally new concept kiln seal design has been generated to replace the (modified) original seals. This new seal system has been designed to provide a very tight long lasting seal which will accommodate the 1.5 inch axial shift and up to 1 inch radial movement of the kiln shell. Design lifetime of the seal is 10,000 operating hours between major maintenance services while maintaining an acceptable leak rate hot or cold, rotating or stopped. The design appears adaptable to any size kiln and is suitable for retrofit to existing kilns. A one-third scale prototype seal assembly is being built to verify the concept prior to construction of the 10 ft diameter seals for the PREPP rotary kiln. 4 figs.

  20. 7 CFR 305.28 - Kiln sterilization treatment schedule.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Kiln sterilization treatment schedule. 305.28 Section 305.28 Agriculture Regulations of the Department of Agriculture (Continued) ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE PHYTOSANITARY TREATMENTS Heat Treatments § 305.28...

  1. MINIMIZATION OF TRANSIENT EMISSIONS FROM ROTARY KILN INCINERATORS

    EPA Science Inventory

    Transient emissions of organics can occur from rotary kiln incinerators when drums containing liquid wastes bound on sorbents are introduced in a batch-wise fashion. Physical processes controlling the release of waste from the sorbent material are greatly affected by the rotation...

  2. TRANSIENT SUPPRESSION PACKAGING FOR REDUCED EMISSIONS FROM ROTARY KILN INCINERATORS

    EPA Science Inventory

    Experiments were performed on a 73 kW rotary kiln incinerator simulator to determine whether innovative waste packaging designs might reduce transient emissions of products of incomplete combustion due to batch charging of containerized liquid surrogate waste compounds bound on g...

  3. Charcoal kiln relicts - a favorable site for tree growth?

    NASA Astrophysics Data System (ADS)

    Buras, Allan; Hirsch, Florian; van der Maaten, Ernst; Takla, Melanie; Räbiger, Christin; Cruz Garcia, Roberto; Schneider, Anna; Raab, Alexandra; Raab, Thomas; Wilmking, Martin

    2015-04-01

    Soils with incompletely combusted organic material (aka 'black carbon') are considered fertile for plant growth. Considerable enrichment of soils with black carbon is known from Chernozems, from anthropogenic induced altering of soils like the 'Terra Preta' in South America (e.g. Glaser, 2001), and from charcoal kiln relicts. Recent studies have reported a high spatial frequency of charcoal kiln relicts in the Northeastern German lowlands (Raab et al., 2015), which today are often overgrown by forest plantations. In this context the question arises whether these sites are favorable for tree growth. Here we compare the performance of 22 Pinus sylvestris individuals - a commonly used tree species in forestry - growing on charcoal kiln relicts with 22 control trees. Growth performance (height growth and diameter growth) of the trees was determined using dendrochronological techniques, i.e. standard ring-width measurements were undertaken on each two cores per tree and tree height was measured in the field. Several other wood properties such as annual wood density, average resin content, as well as wood chemistry were analyzed. Our results indicate that trees growing on charcoal kiln relicts grow significantly less and have a significantly lower wood density in comparison with control trees. Specific chemical components such as Manganese as well as resin contents were significantly higher in kiln trees. These results highlight that tree growth on charcoal kiln relicts is actually hampered instead of enhanced. Possibly this is a combined effect of differing physical soil properties which alter soil water accessibility for plants and differing chemical soil properties which may negatively affect tree growth either if toxic limits are surpassed or if soil nutrient availability is decreased. Additional soil analyses with respect to soil texture and soil chemistry shall reveal further insight into this hypothesis. Given the frequent distribution of charcoal kiln relicts in

  4. 40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., lightweight aggregate kilns, solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces..., solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces to minimize emissions... acid production furnace may request that the Director address permit conditions that minimize...

  5. 40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., lightweight aggregate kilns, solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces..., solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces to minimize emissions... acid production furnace may request that the Director address permit conditions that minimize...

  6. 40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., lightweight aggregate kilns, solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces..., solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces to minimize emissions... acid production furnace may request that the Director address permit conditions that minimize...

  7. 40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., lightweight aggregate kilns, solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces..., solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces to minimize emissions... acid production furnace may request that the Director address permit conditions that minimize...

  8. 40 CFR 270.235 - Options for incinerators, cement kilns, lightweight aggregate kilns, solid fuel boilers, liquid...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., lightweight aggregate kilns, solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces..., solid fuel boilers, liquid fuel boilers and hydrochloric acid production furnaces to minimize emissions... acid production furnace may request that the Director address permit conditions that minimize...

  9. Development of cleaner-burning brick kilns in Ciudad Juarez, Chihuahua, Mexico.

    PubMed

    Bruce, Charles W; Corral, Alba Yadira; Lara, Antonio S

    2007-04-01

    The following results provide a comparison between net airborne contamination produced by the traditional form of kiln used in Northern Mexico and by those modified according to a design by Dr. Robert Marquez. What has become known as the MK style kiln was intended to significantly reduce contaminant emissions. The concept involves covering the kiln with a dome and channeling the output of an active kiln through a second, identical loaded kiln for its additional filtration of the effluents. Kilns of a pair are connected via clay brick channels. The roles are reversed after the initial kiln is refilled. Significant reductions in the particulate and gaseous emissions were achieved in the prototype system, but a connectional problem with recent kiln pairs has also limited the degree of operational success. The problem did not mask the potential of the MK kiln, as will be shown. Additional anticipated benefits to the owners of MK kilns, such as reduced operating cycles and decreased quantities of fuel, also have been verified. Key measurements made during all of the burns were of aerosol densities and buoyancies in the flues, kiln temperatures, and, on a number of occasions, chemical analyses of both aerosol and gaseous effluents. Continuous time histories of aerosol densities for most burns (of a total of -40) provide a basis for examining features and the effects of differing styles of operation with respect to burn efficiency and net contaminant masses. Covering the active kiln with a dome produces a net reduction in dry aerosol effluent mass of a factor between 5 and 10, whereas the addition of a filter kiln produces a net reduction of about a factor of 2. The use of used motor oil as a fuel further reduced aerosol contamination by -1 order of magnitude.

  10. Torrefaction of cedarwood in a pilot scale rotary kiln and the influence of industrial flue gas.

    PubMed

    Mei, Yanyang; Liu, Rujie; Yang, Qing; Yang, Haiping; Shao, Jingai; Draper, Christopher; Zhang, Shihong; Chen, Hanping

    2015-02-01

    Torrefaction of cedarwood was performed in a pilot-scale rotary kiln at various temperatures (200, 230, 260 and 290°C). The torrefaction properties, the influence on the grindability and hydroscopicity of the torrefied biomass were investigated in detail as well as the combustion performance. It turned out that, compared with raw biomass, the grindability and the hydrophobicity of the torrefied biomass were significantly improved, and the increasing torrefaction temperature resulted in a decrease in grinding energy consumption and an increase in the proportion of smaller-sized particles. The use of industrial flue gas had a significant influence on the behavior of cedarwood during torrefaction and the properties of the resultant solid products. To optimize the energy density and energy yield, the temperature of torrefaction using flue gas should be controlled within 260°C. Additionally, the combustion of torrefied samples was mainly the combustion of chars, with similar combustion characteristics to lignite.

  11. Employing Synergetic Effect of Doping and Thin Film Coating to Boost the Performance of Lithium-Ion Battery Cathode Particles.

    PubMed

    Patel, Rajankumar L; Jiang, Ying-Bing; Choudhury, Amitava; Liang, Xinhua

    2016-05-04

    Atomic layer deposition (ALD) has evolved as an important technique to coat conformal protective thin films on cathode and anode particles of lithium ion batteries to enhance their electrochemical performance. Coating a conformal, conductive and optimal ultrathin film on cathode particles has significantly increased the capacity retention and cycle life as demonstrated in our previous work. In this work, we have unearthed the synergetic effect of electrochemically active iron oxide films coating and partial doping of iron on LiMn1.5Ni0.5O4 (LMNO) particles. The ionic Fe penetrates into the lattice structure of LMNO during the ALD process. After the structural defects were saturated, the iron started participating in formation of ultrathin oxide films on LMNO particle surface. Owing to the conductive nature of iron oxide films, with an optimal film thickness of ~0.6 nm, the initial capacity improved by ~25% at room temperature and by ~26% at an elevated temperature of 55 °C at a 1C cycling rate. The synergy of doping of LMNO with iron combined with the conductive and protective nature of the optimal iron oxide film led to a high capacity retention (~93% at room temperature and ~91% at 55 °C) even after 1,000 cycles at a 1C cycling rate.

  12. Employing Synergetic Effect of Doping and Thin Film Coating to Boost the Performance of Lithium-Ion Battery Cathode Particles

    NASA Astrophysics Data System (ADS)

    Patel, Rajankumar L.; Jiang, Ying-Bing; Choudhury, Amitava; Liang, Xinhua

    2016-05-01

    Atomic layer deposition (ALD) has evolved as an important technique to coat conformal protective thin films on cathode and anode particles of lithium ion batteries to enhance their electrochemical performance. Coating a conformal, conductive and optimal ultrathin film on cathode particles has significantly increased the capacity retention and cycle life as demonstrated in our previous work. In this work, we have unearthed the synergetic effect of electrochemically active iron oxide films coating and partial doping of iron on LiMn1.5Ni0.5O4 (LMNO) particles. The ionic Fe penetrates into the lattice structure of LMNO during the ALD process. After the structural defects were saturated, the iron started participating in formation of ultrathin oxide films on LMNO particle surface. Owing to the conductive nature of iron oxide films, with an optimal film thickness of ~0.6 nm, the initial capacity improved by ~25% at room temperature and by ~26% at an elevated temperature of 55 °C at a 1C cycling rate. The synergy of doping of LMNO with iron combined with the conductive and protective nature of the optimal iron oxide film led to a high capacity retention (~93% at room temperature and ~91% at 55 °C) even after 1,000 cycles at a 1C cycling rate.

  13. Employing Synergetic Effect of Doping and Thin Film Coating to Boost the Performance of Lithium-Ion Battery Cathode Particles

    PubMed Central

    Patel, Rajankumar L.; Jiang, Ying-Bing; Choudhury, Amitava; Liang, Xinhua

    2016-01-01

    Atomic layer deposition (ALD) has evolved as an important technique to coat conformal protective thin films on cathode and anode particles of lithium ion batteries to enhance their electrochemical performance. Coating a conformal, conductive and optimal ultrathin film on cathode particles has significantly increased the capacity retention and cycle life as demonstrated in our previous work. In this work, we have unearthed the synergetic effect of electrochemically active iron oxide films coating and partial doping of iron on LiMn1.5Ni0.5O4 (LMNO) particles. The ionic Fe penetrates into the lattice structure of LMNO during the ALD process. After the structural defects were saturated, the iron started participating in formation of ultrathin oxide films on LMNO particle surface. Owing to the conductive nature of iron oxide films, with an optimal film thickness of ~0.6 nm, the initial capacity improved by ~25% at room temperature and by ~26% at an elevated temperature of 55 °C at a 1C cycling rate. The synergy of doping of LMNO with iron combined with the conductive and protective nature of the optimal iron oxide film led to a high capacity retention (~93% at room temperature and ~91% at 55 °C) even after 1,000 cycles at a 1C cycling rate. PMID:27142704

  14. Occurrence of transient puffs in a rotary-kiln incinerator simulator

    SciTech Connect

    Linak, W.P.; Kilgroe, J.D.; McSorley, J.A.; Wendt, J.O.L.; Dunn, J.E.

    1987-01-01

    This article discusses a statistically designed parametric investigation to determine which waste and kiln variables (charge mass, charge surface area, charge composition, and kiln temperature) significantly affect both instantaneous intensity and total magnitude of the puffs leaving a kiln used to incinerate simple prototype plastic wastes, ranging from polyethylene to polyvinychloride. Results show the relative ease with which failure conditions are achieved, even at high excess air values and high kiln temperatures. Transient puffs leaving the kiln contain a number of hazardous compounds. Increasing kiln temperature does not necessarily decrease the puff intensity and may in fact cause an increase. However, the total mass emitted always decreases with increasing temperature. In addition, the mass, surface area, and composition of the charge are all important.

  15. Static analysis of masonry kilns built with fictile tubules bricks

    NASA Astrophysics Data System (ADS)

    Olivito, Renato S.; Scuro, Carmelo; Codispoti, Rosamaria

    2016-12-01

    Industrial archeology is a branch that studies all the testimony (tangible and intangible, direct and indirect) related to the process of industrialization since its origins. This technical field is based on an interdisciplinary approach, it has the task of deepening the story, understanding the technological development made by man over the centuries. The present work focused attention on the study and analysis of a masonry kiln, built with the technique of hollow clay fictile tubules. The study, in particular, has been carried out analyzing the stress state caused by the wind on the structure. The kiln is constituted by a particular geometric configuration that develops in height due to the presence of chimney over the dome.

  16. Performance of rotary kiln reactor for the elephant grass pyrolysis.

    PubMed

    De Conto, D; Silvestre, W P; Baldasso, C; Godinho, M

    2016-10-01

    The influence of process conditions (rotary speed/temperature) on the performance of a rotary kiln reactor for non-catalytic pyrolysis of a perennial grass (elephant grass) was investigated. The product yields, the production of non-condensable gases as well as the biochar properties were evaluated. The maximum H2 yield was close to that observed for catalytic pyrolysis processes, while the bio-oil yield was higher than reported for pyrolysis of other biomass in rotary kiln reactors. A H2/CO ratio suitable for Fischer-Tropsch synthesis (FTS) was obtained. The biochars presented an alkaline pH (above 10) and interesting contents of nutrients, as well as low electrical conductivity, indicating a high potential as soil amendment.

  17. Synthetic aggregates from combustion ashes using an innovative rotary kiln.

    PubMed

    Wainwright, P J; Cresswell, D J

    2001-01-01

    This paper describes the use of a number of different combustion ashes to manufacture synthetic aggregates using an innovative rotary 'Trefoil' kiln. Three types of combustion ash were used, namely: incinerated sewage sludge ash (ISSA); municipal solid waste incinerator bottom ash (MSWIBA-- referred to here as BA); and pulverised fuel ash (Pfa). The fine waste ash fractions listed above were combined with a binder to create a plastic mix that was capable of being formed into 'green pellets'. These pellets were then fired in a Trefoil kiln to sinter the ashes into hard fused aggregates that were then tested for use as a replacement for the natural coarse aggregate in concrete. Results up to 28 days showed that these synthetic aggregates were capable of producing concretes with compressive strengths ranging from 33 to 51 MPa, equivalent to between 73 and 112% of that of the control concrete made with natural aggregates.

  18. Mössbauer Study of a Celtic Pottery-Making Kiln in Lower Bavaria

    NASA Astrophysics Data System (ADS)

    Gebhard, R.; Guggenbichler, E.; Häusler, W.; Riederer, J.; Schmotz, K.; Wagner, F. E.; Wagner, U.

    2004-06-01

    In 1995 a well preserved 3rd century BC Celtic kiln for pottery making was excavated at Schmiedorf in Lower Bavaria. The firing chamber and the flue plate of the kiln were preserved, whereas the dome was not found. We report on a study of material from this kiln by neutron activation analysis, thin-section microscopy, X-ray diffraction and Mössbauer spectroscopy, all performed with the aim to learn more about pottery-making procedures in Celtic times.

  19. Effect of kiln dust from a cement factory on growth of Vicia faba L.

    PubMed

    Uysal, Ismet; Ozdilek, Hasan Göksel; Oztürk, Münir

    2012-04-01

    This study was undertaken to study the effects of different amounts of kiln dust mixed with soil on the seed germination, plant growth, leaf area and water content of Vicia faba cv. Eresen. The reason for this was that cement kiln dust generated as a by-product from the cement factories is rich in potassium, sulfate and other compounds. This product becomes a serious problem when it comes in contact with water. The dust was collected from a cement factory located in Canakkale. Various elements such as Al, Co, Mo, Ca, B, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, P, Pb, S, Se and Zn were determined both in soil as well as kiln dust. Kiln dust was mixed with soil in pots (20 cm diameter) to make seven different treatments varying from 15 to 105 g kiln dust kg(-1) of soil. The experiment lasted for 4 months. Seeds of V faba were sown in the pots filled with mixtures of preanalysed kiln dust and soil. Germination was high in the pots with a lower treatment of cement kiln dust. However, lower germination rates were observed in the pots mixed with the highest and the medium amounts of cement kiln dust. Plants growing in the soil including 15 g kiln dust showed better performance in length as compared to control. Leaf area increased with increase in cement kiln dust content up to 60 g kiln dust kg(-1) of soil, but declined after 75 g kg(-1). Water content of leaves (mg cm(-2) leaf area) was found to be constantly decreasing with respect to increasing cement kiln content in the pots. Differences between the averages were evaluated by Tukey test and results were found to be significant.

  20. [Study on colored drawing technique of Qionglai kiln by SRXRF].

    PubMed

    Luan, Tian; Mao, Zhen-Wei; Wang, Chang-Sui

    2006-08-01

    The colored drawing technique of Qionglai kiln is a debate problem in the archaeology and ancient ceramic research. In the present paper, SRXRF linescan technology was used to study the distribution mode of the colorific elements on the cross-sections of samples. The analytical result indicates that there existed two kinds of decoration techniques of colored drawing, i. e. the techniques of the underglaze color and oveglaze color coexisted in that time.

  1. Method and system including a double rotary kiln pyrolysis or gasification of waste material

    SciTech Connect

    McIntosh, M.J.; Arzoumanidis, G.G.

    1997-09-02

    A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet. 5 figs.

  2. Advantages and disadvantages of burning hazardous waste in a precalciner kiln

    SciTech Connect

    Johnson, N.; Kluesner, M.

    1997-12-31

    Lone Star Industries, Inc., operates a precalciner kiln in Cape Girardeau, Missouri. In May 1992, the company started burning hazardous waste in the hot end of the kiln as a partial fuel replacement. This paper examines the advantages and disadvantages Lone Star has experienced since it began using hazardous waste as an alternate fuel supply. The use of hazardous waste has produced a number of ancillary benefits and a few hindrances to kiln operations. How each of these aspects has affected kiln operation and performance will be examined. 4 tabs.

  3. Method and system including a double rotary kiln pyrolysis or gasification of waste material

    DOEpatents

    McIntosh, Michael J.; Arzoumanidis, Gregory G.

    1997-01-01

    A method of destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500.degree. C. to heat the particulate material to a temperature in the range of from about 200.degree. C. to about 900.degree. C. in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

  4. Process and shaft kiln for the burning of lime or similar bulk materials

    SciTech Connect

    Von Z. H.

    1981-09-01

    A proces is disclosed for the burning of lime, cement or other lumpy bulk materials in a shaft kiln using coal. Coal dust or particulated dry coal is continuously fed into a gasification chamber positioned in the center of the shaft kiln and is therein partially or fully gasified by the addition of air in substoichiometric proportions. The partially or fully gasified fuel is mixed with air at an elevated temperature. Such mixture is then burned in the burning zone of the shaft kiln. The flow of the heating medium, i.e., the burnt fuel, and the flow of the kiln charge are co-current within the kiln. The shaft kiln has a centrally positioned gasification chamber which is mounted on radial supports which are positioned in the shaft kiln in such a way as to produce a space below the supports. The space is substantially free from kiln charge. Uniform distribution of the gases is guaranteed across the cross section of the shaft kiln by the space.

  5. A method and system including a double rotary kiln pyrolysis or gasification of waste material

    SciTech Connect

    McIntosh, M.J.; Arzoumanidis, G.G.

    1995-12-31

    A method is described for destructively distilling an organic material in particulate form wherein the particulates are introduced through an inlet into one end of an inner rotating kiln ganged to and coaxial with an outer rotating kiln. The inner and outer kilns define a cylindrical annular space with the inlet being positioned in registry with the axis of rotation of the ganged kilns. During operation, the temperature of the wall of the inner rotary kiln at the inlet is not less than about 500 C to heat the particulate material to a temperature in the range of from about 200 C to about 900 C in a pyrolyzing atmosphere to reduce the particulate material as it moves from the one end toward the other end. The reduced particulates including char are transferred to the annular space between the inner and the outer rotating kilns near the other end of the inner rotating kiln and moved longitudinally in the annular space from near the other end toward the one end in the presence of oxygen to combust the char at an elevated temperature to produce a waste material including ash. Also, heat is provided which is transferred to the inner kiln. The waste material including ash leaves the outer rotating kiln near the one end and the pyrolysis vapor leaves through the particulate material inlet.

  6. Kiln dust-fly ash systems for highway bases and subbases

    SciTech Connect

    Not Available

    1982-10-01

    The purpose of this investigation was to determine the effectiveness of substituting kiln dusts for hydrated lime in lime-fly ash-aggregate road base systems. A total of 45 kiln dust samples, including 33 cement dusts and 12 lime dusts, were obtained in accordance with a standard sampling procedure. In addition, 18 fly ashes (including 5 Class C ash samples) and 6 aggregates were included in the sampling program. Kiln dust and fly ash samples were characterized by Trow, Ltd. to determine physical properties and chemical, as well as mineralogical, composition. Optimum kiln dust-fly ash ratios were developed for 66 mix combinations. Kiln dust-fly ash-aggregate compressive strength tests were performed. Engineering properties (durability, volume stability, etc.) of optimum mix combinations were tested and compared with conventional lime-fly ash-aggregate mixtures. Most kiln dust-fly ash-aggregate mixes were comparable to, and in many cases demonstrated higher early strength development than, lime-fly ash-aggregate mixes. Optimum mix strengths for kiln dust-fly ash-aggregate compositions were generally attained at kiln dust-fly ash ratios of 2:1 using cement kiln dust and 1:1 using lime kiln dust. By contrast, most lime-fly ash-aggregate mixes have lime-fly ash ratios of 1:3 or 1:4. Therefore, higher concentrations of kiln dust are required compared to commercial lime. Mixes containing Class C fly ash developed higher strengths than comparable mixes with Class F fly ash.

  7. Recycling ash into the first stage of cyclone pre-heater of cement kiln.

    PubMed

    Zhan, Ming-Xiu; Fu, Jian-Ying; Havukainen, Jouni; Chen, Tong; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-10-01

    Fly ash collected from the bag filter could be recycled into the first stage of the cyclone pre-heater of the cement kiln, resulting in the possible enrichment of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In this study, soxhlet fly ash (SFA) and raw meal (RM) were selected as the basis for the PCDD/F formation experiments. The levels of 2,3,7,8-PCDD/Fs formed on the SFA and RM were observed to be 2550pg/g (157pg I-TEQ/g) and 1142pg/g (55pg I-TEQ/g), respectively. While less 2,3,7,8-PCDD/Fs was detected when SFA was mixed with RM, suggesting that recycling cement kiln ash would not largely increase the concentration of PCDD/Fs in flue gas. Furthermore, the possible influencing factors on the PCDD/F formation were also investigated. The formation of 2,3,7,8-PCDD/Fs was up to 10,871pg/g (380pg I-TEQ/g) with the adding of CuCl2, which was much higher than the results of CuO and activated carbon. Most importantly, the homologue, congener and gas/particle distribution of PCDD/Fs indicated that de novo synthesis was the dominant PCDD/F formation pathway for SFA. Lastly, principal component analysis (PCA) was also conducted to identify the relationship between the compositions of reactant and the properties of PCDD/Fs produced.

  8. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL... Hazardous Waste Combustors Replacement Emissions Standards and Operating Limits for Incinerators, Cement... burning cement kilns? (a) Emission and hazardous waste feed limits for existing sources. You must...

  9. 40 CFR 63.1220 - What are the replacement standards for hazardous waste burning cement kilns?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... hazardous waste burning cement kilns? 63.1220 Section 63.1220 Protection of Environment ENVIRONMENTAL... Hazardous Waste Combustors Replacement Emissions Standards and Operating Limits for Incinerators, Cement... burning cement kilns? (a) Emission and hazardous waste feed limits for existing sources. You must...

  10. Rotary kiln incineration of dichloromethane and xylene: A comparison of incinerability characteristics under various operating conditions

    SciTech Connect

    Cundy, V.A.; Lu, C.; Cook, C.A.; Sterling, A.M.; Leger, C.B.; Jakway, A.L.; Montestruc, A.N.; Conway, R. ); Lester, T.W. )

    1991-08-01

    Comparisons are made, for the first time, between the combustion characteristics of dicholoromethane and xylene in an industrial rotary kiln incinerator. The comparisons are made under different operating conditions, including variable kiln rotation rate and operation both with and without turbulence air. Continuous gas composition and temperature measurements and batch gas composition measurements were obtained from two vertical locations near the exit region of the rotary kiln. The measurements show that there is significant vertical stratification at the exit of the kiln. Addition of turbulence air enhanced combustion conditions throughout the kiln during xylene processing. During dichloromethane processing, however, the addition of turbulence air had minimal effect and only promoted greater bulk mixing; chlorinated compounds transported from the lower kiln during operation with turbulence air were not efficiently processed in the upper kiln. Evolution of test liquids from the bed was not constant but rather was characterized by intermittent peaks. The field-scale data of this work suggest that the evolution rate of the test liquid was increased as kiln rotation rate increased. Many of the differences between xylene and dichloromethane processing during these experiments are explained by a simple stoichiometric analysis.

  11. A Thermoelectric Waste-Heat-Recovery System for Portland Cement Rotary Kilns

    NASA Astrophysics Data System (ADS)

    Luo, Qi; Li, Peng; Cai, Lanlan; Zhou, Pingwang; Tang, Di; Zhai, Pengcheng; Zhang, Qingjie

    2015-06-01

    Portland cement is produced by one of the most energy-intensive industrial processes. Energy consumption in the manufacture of Portland cement is approximately 110-120 kWh ton-1. The cement rotary kiln is the crucial equipment used for cement production. Approximately 10-15% of the energy consumed in production of the cement clinker is directly dissipated into the atmosphere through the external surface of the rotary kiln. Innovative technology for energy conservation is urgently needed by the cement industry. In this paper we propose a novel thermoelectric waste-heat-recovery system to reduce heat losses from cement rotary kilns. This system is configured as an array of thermoelectric generation units arranged longitudinally on a secondary shell coaxial with the rotary kiln. A mathematical model was developed for estimation of the performance of waste heat recovery. Discussions mainly focus on electricity generation and energy saving, taking a Φ4.8 × 72 m cement rotary kiln as an example. Results show that the Bi2Te3-PbTe hybrid thermoelectric waste-heat-recovery system can generate approximately 211 kW electrical power while saving 3283 kW energy. Compared with the kiln without the thermoelectric recovery system, the kiln with the system can recover more than 32.85% of the energy that used to be lost as waste heat through the kiln surface.

  12. MECHANISMS GOVERNING TRANSIENTS FROM THE BATCH INCINERATION OF LIQUID WASTES IN ROTARY KILNS

    EPA Science Inventory

    When "containerized" liquid wastes, bound on sorbents. are introduced into a rotary kiln in a batch mode, transient phenomena in-volving heat transfer into, and waste mass transfer out of, the sorbent can oromote the raoid release of waste vaoor into the kiln environment. This ra...

  13. Investment opportunity: the FPL (Forest Products Laboratory) low-cost solar-dry kiln

    SciTech Connect

    Harpole, G.B.

    1988-09-01

    Two equations are presented that may be used to estimate a maximum investment limit and working capital requirements for the FPL low-cost solar-dry kiln systems. The equations require data for drying-cycle time, green-lumber cost, and kiln-dried lumber costs. Results are intended to provide a preliminary estimate.

  14. EMISSIONS OF AIR TOXICS FROM A SIMULATED CHARCOAL KILN EQUIPPED WITH AN AFTERBURNER

    EPA Science Inventory

    The report discusses emissions of air toxics from a simulated charcoal kiln equipped with an afterburner. A laboratory-scale simulator was constructed and tested to determine if it could be used to produce charcoal that was similar to that produced in Missouri-type charcoal kilns...

  15. Method and apparatus for maximizing throughput of indirectly heated rotary kilns

    DOEpatents

    Coates, Ralph L; Smoot, Douglas L.; Hatfield, Kent E

    2016-06-21

    An apparatus and method for achieving improved throughput capacity of indirectly heated rotary kilns used to produce pyrolysis products such as shale oils or coal oils that are susceptible to decomposition by high kiln wall temperatures is disclosed. High throughput is achieved by firing the kiln such that optimum wall temperatures are maintained beginning at the point where the materials enter the heating section of the kiln and extending to the point where the materials leave the heated section. Multiple high velocity burners are arranged such that combustion products directly impact on the area of the kiln wall covered internally by the solid material being heated. Firing rates for the burners are controlled to maintain optimum wall temperatures.

  16. Method and apparatus for maximizing throughput of indirectly heated rotary kilns

    DOEpatents

    Coates, Ralph L; Smoot, L. Douglas; Hatfield, Kent E

    2012-10-30

    An apparatus and method for achieving improved throughput capacity of indirectly heated rotary kilns used to produce pyrolysis products such as shale oils or coal oils that are susceptible to decomposition by high kiln wall temperatures is disclosed. High throughput is achieved by firing the kiln such that optimum wall temperatures are maintained beginning at the point where the materials enter the heating section of the kiln and extending to the point where the materials leave the heated section. Multiple high velocity burners are arranged such that combustion products directly impact on the area of the kiln wall covered internally by the solid material being heated. Firing rates for the burners are controlled to maintain optimum wall temperatures.

  17. Modification of Waelz kiln processing of La Oroya zinc ferrite

    SciTech Connect

    Holloway, P.C.; Etsell, T.H.; Murland, A.L.

    2008-05-15

    La Oroya zinc ferrite (19.5% Zn, 26.6% Fe, 0.052% Ga, 0.075% In) was roasted with coal under conditions more oxidizing than normally used in a Waelz kiln, and the roasted residues were leached with 200 g/L H{sub 2}SO{sub 4}. Overall zinc recoveries of up to 97% were achieved, with 35% of the zinc reporting to the fume after roasting at 1,100{sup o}C with a bituminous coal addition of 20%. Under these conditions, 93.2% of the Cd, 13.4% of the Cu, 33% of the Ga, 61% of the In and 18.2% of the Pb were recovered either in the fume or in the leach solution. At 2006 metal prices, the value of the recovered metals is comparable to that obtained from commercial Waelz kiln processing of this residue. Zinc in the franklinite (ZnFe{sub 2}O{sub 4}) mineral is reduced to zinc vapor, and, after oxidation, some of the zinc is found as ZnO or as Zn{sub 2}SiO{sub 4} in the roasted residue. Iron reacts to form either hematite (Fe{sub 2}O{sub 3}) or magnetite (Fe{sub 3}O{sub 4}), with no metallic iron detected in the roasted residue, and less than 2% of the iron is solubilized during leaching. The residue produced after roasting and leaching is, therefore, much more stable than the residue from Waelz kiln processing and should be suitable for disposal in a landfill.

  18. Carpet As An Alternative Fuel in Cement Kilns

    SciTech Connect

    Matthew J Realff

    2007-02-06

    Approximately 5 billion lbs of carpet will be removed from buildings in the US each year for the foreseeable future. This carpet is potentially a valuable resource because it contains plastic in the face of the carpet that can be re-used. However, there are many different types of carpet, and at least four major different plastics used to make the face. The face is woven through a backing fabric and held in place by a “glue” that is in most cases a latex cross-linked polymer which is heavily loaded with chalk (calcium carbonate). This backing has almost no value as a recycled material. In addition, carpet is a bulky material that is difficult to handle and ship and must be kept dry. It would be of significant benefit to the public if this stream of material could be kept out of landfills and some of its potential value unlocked by having high volume alternatives for recycled carpet use. The research question that this project investigated was whether carpet could be used as a fuel in a cement kiln. If this could be done successfully, there is significant capacity in the US cement industry to absorb carpet and use it as a fuel. Cement kilns could serve as a way to stimulate carpet collection and then side streams be taken for higher value uses. The research demonstrated that carpet was technically a suitable fuel, but was unable to conclude that the overall system could be economically feasible at this time with the constraints placed on the project by using an existing system for feeding the kiln. Collection and transportation were relatively straightforward, using an existing collector who had the capacity to collect high volumes of material. The shredding of the carpet into a suitable form for feeding was more challenging, but these problems were successfully overcome. The feeding of the carpet into the kiln was not successfully carried out reliably. The overall economics were not positive under the prevailing conditions of costs for transportation and size

  19. Kiln for hot-pressing compacts in a continuous manner

    DOEpatents

    Reynolds, C.D Jr.

    1983-08-08

    The invention is directed to a hot pressing furnace or kiln which is capable of preheating, hot pressing, and cooling a plurality of articles in a sequential and continuous manner. The hot pressing furnace of the present invention comprises an elongated, horizontally disposed furnace capable of holding a plurality of displaceable pusher plates each supporting a die body loaded with refractory or ceramic material to be hot pressed. Each of these plates and the die body supported thereby is sequentially pushed through the preheating zone, a temperature stabilizing and a hot pressing zone, and a cooling zone so as to provide a continuous hot-pressing operation of a plurality of articles.

  20. Kiln for hot-pressing compacts in a continuous manner

    DOEpatents

    Reynolds, Jr., Carl D.

    1985-01-01

    The present invention is directed to a hot pressing furnace or kiln which is capable of preheating, hot pressing, and cooling a plurality of articles in a sequential and continuous manner. The hot pressing furnace of the present invention comprises an elongated, horizontally disposed furnace capable of holding a plurality of displaceable pusher plates each supporting a die body loaded with refractory or ceramic material to be hot pressed. Each of these plates and the die body supported thereby is sequentially pushed through the preheating zone, a temperature stabilizing and a hot pressing zone, and a cooling zone so as to provide a continuous hot-pressing operation of a plurality of articles.

  1. Integrated assessment of brick kiln emission impacts on air quality.

    PubMed

    Le, Hoang Anh; Oanh, Nguyen Thi Kim

    2010-12-01

    This paper presents monitoring results of daily brick kiln stack emission and the derived emission factors. Emission of individual air pollutant varied significantly during a firing batch (7 days) and between kilns. Average emission factors per 1,000 bricks were 6.35-12.3 kg of CO, 0.52-5.9 kg of SO(2) and 0.64-1.4 kg of particulate matter (PM). PM emission size distribution in the stack plume was determined using a modified cascade impactor. Obtained emission factors and PM size distribution data were used in simulation study using the Industrial Source Complex Short-Term (ISCST3) dispersion model. The model performance was successfully evaluated for the local conditions using the simultaneous ambient monitoring data in 2006 and 2007. SO(2) was the most critical pollutant, exceeding the hourly National Ambient Air Quality Standards over 63 km(2) out of the 100-km(2) modelled domain in the base case. Impacts of different emission scenarios on the ambient air quality (SO(2), PM, CO, PM dry deposition flux) were assessed.

  2. Acceptable approaches for beneficial use of cement kiln dust

    SciTech Connect

    Schreiber, R.J.; Smeenk, S.D.

    1998-12-31

    One beneficial use of cement kiln dust (CKD) is application of CKD to cropland as agricultural lime or fertilizer. However, the EPA has expressed a concern over land application of CKD when the metals constituents in the CKD are above the industry-wide median levels presented in EPA`s Report to Congress on Cement Kiln Dust. Under the Clean Water Act, EPA has established limits for metals concentrations in sewage sludge that is applied to the land for beneficial use of the nitrogen in the sludge. The limits for land application of sewage sludge were established based on the results of exposure risk assessments. A comparison of the median industry-wide metals concentrations in CKD to the metals concentration limits for land application of sewage sludge indicates that all trace metal concentrations IN CKD are below the corresponding sewage sludge land application limit, with the exception of the median level of arsenic from one data set. EPA has determined that land application of CKD with metals concentration limits at or below the industry-wide median concentrations does not pose a significant human cancer or non-cancer health risk. Therefore, with appropriate limits, CKD can be beneficially reused for land application on agricultural land in a manner that is protective of human health and the environment.

  3. Improvements of gas-fired kiln by use of a microcomputer control system for the porcelain manufacture

    SciTech Connect

    Loong, H.; Liang, C.C.; Tseng, K.T.

    1988-01-01

    The use of microcomputer control system to gas-fired kiln not only enhanced the porcelain kiln's productivity from 75% to 95% but also saved its operation cost around US$ 200,000 per year. The self-designed microcomputer control system can simultaneous set and control the firing conditions of the period kiln which was built up in our laboratory. Our period kiln having volume of 4 M/sup 3/ was insulated by ceramic fiber which is different from use of refractory in traditional kilns. At the bottom of the kiln is an off-gas tunnel connected with a chimney. Besides the auto start-up and continuous operation of kiln, the main functions of this microcomputer control system are summarized.

  4. Comparison of the fixation effects of heavy metals by cement rotary kiln co-processing and cement based solidification/stabilization.

    PubMed

    Zhang, Junli; Liu, Jianguo; Li, Cheng; Jin, Yiying; Nie, Yongfeng; Li, Jinhui

    2009-06-15

    Cement rotary kiln co-processing of hazardous wastes and cement based solidification/stabilization could both immobilize heavy metals. The different retention mechanisms of the two technologies lead to different fixation effects of heavy metals. The same amount of heavy metal compounds were treated by the two types of fixation technologies. Long-term leaching test (160 days), the maximum availability leaching test (NEN 7341) and a modified three-step sequential extraction procedure, proposed by the Commission of the European Communities Bureau of Reference (BCR) were employed to compare the fixation effects of the two fixation technologies. The leaching concentrations in NEN 7341 and long-term leaching tests were compared with identification standard for hazardous wastes (GB5085.3-1996) and drinking water standard (GB5749-2005). The results indicate that the leaching concentrations of the long-term leaching test and NEN 7341 test were lower than the regulatory limits and the leached ratios were small. Both cement based solidification/stabilization and cement rotary kiln co-processing could effectively fix heavy metals. Calcination in a cement rotary kiln and the following hydration that follows during cement application could fix As, Cd, Pb and Zn more effectively and decrease the release to the environment. Cement solidification/stabilization technology has better effect in immobilizing Cr and Ni. Cr wastes are more fitful to be treated by cement solidification/stabilization.

  5. Evaluation of the thermal stability POHC incinerability ranking in a pilot-scale rotary kiln incinerator

    SciTech Connect

    Lee, J.W.; Waterland, L.R.; Whitworth, W.E.; Carroll, G.J.

    1991-01-01

    A series of pilot-scale incineration tests was performed at EPA's Incineration Research Facility to evaluate the thermal stability-based POHC incinerability ranking. In the tests, mixtures of 12 POHCs with predicted incinerability spanning the range of most to least difficult to incinerate class were combined with a clay-based sorbent and batch-fed to the facility's pilot-scale rotary kiln incinerator via a fiberpack drum ram feeder. Kiln operating conditions were varied to include a baseline operating condition, three modes of attempted incineration failure, and a worst case combination of the three failure modes. Kiln exit POHC DREs were in the 99.99 percent range for the volatile POHCs for the baseline, mixing failure (increased charge mass), and matrix failure (decreased feed H/C) tests. Semivolatile POHCs were not detected in the kiln exit for these tests; corresponding DREs were generally greater than 99.999 percent. The thermal failure (low kiln temperature) and worst case (combination of thermal, mixing, and matrix failure) tests resulted in substantially decreased kiln exit POHC DREs. These ranged from 99 percent or less for Freon 113 to greater than 99.999 percent for the less stable-ranked semivolatile POHCs. General agreement between relative kiln exit POHC DRE and predicted incinerability class was observed.

  6. Effect of brick kiln emissions on commonly used vegetables of Kashmir Valley.

    PubMed

    Skinder, Bhat M; Sheikh, Afeefa Q; Pandit, Ashok K; Ganai, Bashir A; Kuchy, Aashiq H

    2015-11-01

    To study the impact of brick kiln emissions on plant growth and productivity, a study was conducted on various biochemical parameters of three main vegetables Brassica oleracea L., Phaseolus vulgaris L., and Solanum melongena L. cultivated in the vicinity of the brick kiln area of the Panzan village of district Budgam (J&K). Plants in the vicinity of brick kilns are direct recipients of emissions and therefore important materials for assessing potential effects of kiln pollutants. The biochemical values of all the three vegetables of the brick kiln site when compared to the control site are significantly (P ≤ 0.05) different. The findings of the present work depict that the brick kilns are the prime reason for the deterioration of important consumable vegetables, which could lead to chaos in the food security of the area in concern besides a threat to local people in terms of health if proper pollution control devices or the replacement of brick kilns are not put in place with new technology.

  7. Carbon reactivation by externally-fired rotary kiln furnace. Final report Oct 75-Jan 78

    SciTech Connect

    Chen, C.; Directo, L.S.

    1980-08-01

    An externally-fired rotary kiln furnace system has been evaluated for cost-effectiveness in carbon reactivation at the Pomona Advanced Wastewater Treatment Research Facility. The pilot scale rotary kiln furnace was operated within the range of 682 kg/day (1,500 lb/day) to 909 kg/day (2,000 lb/day). The rotary kiln furnace was found to be as effective as the multiple hearth furnace in reactivating the exhausted granular activated carbon. The operating and maintenance of the rotary kiln system required less operator skill than the multiple hearth furnace system. However, the corrosion rate was higher in the rotary tube than in the multiple hearth furnace. Cost estimates based on a typical regeneration capacity of 182 kg/hr (400 lb/hr) have been made for both rotary kiln and multiple hearth furnace systems. These indicate that the capital cost for the multiple hearth furnace is about two times that of the rotary kiln furnace. The operation and maintenance costs for both furnace systems are similar. The overall process costs for the multiple hearth and rotary kiln furnace systems are estimated to be 33.2 cents/kg (15.1 cents/lb) of carbon regenerated and 29.2 cents/kg (13.3 cents/lb) of carbon regenerated, respectively.

  8. Coal desulfurization in a rotary kiln combustor. Final report, March 15, 1990--July 31, 1991

    SciTech Connect

    Cobb, J.T. Jr.

    1992-09-11

    The purpose of this project was to demonstrate the combustion of coal and coal wastes in a rotary kiln reactor with limestone addition for sulfur control. The rationale for the project was the perception that rotary systems could bring several advantages to combustion of these fuels, and may thus offer an alternative to fluid-bed boilers. Towards this end, an existing wood pyrolysis kiln (the Humphrey Charcoal kiln) was to be suitably refurbished and retrofitted with a specially designed version of a patented air distributor provided by Universal Energy, Inc. (UEI). As the project progressed beyond the initial stages, a number of issues were raised regarding the feasibility and the possible advantages of burning coals in a rotary kiln combustor and, in particular, the suitability of the Humphrey Charcoal kiln as a combustor. Instead, an opportunity arose to conduct combustion tests in the PEDCO Rotary Cascading-Bed Boiler (RCBB) commercial demonstration unit at the North American Rayon CO. (NARCO) in Elizabethton, TN. The tests focused on anthracite culm and had two objectives: (a) determine the feasibility of burning anthracite culms in a rotary kiln boiler and (b) obtain input for any further work involving the Humphrey Charcoal kiln combustor. A number of tests were conducted at the PEDCO unit. The last one was conducted on anthracite culm procured directly from the feed bin of a commercial circulating fluid-bed boiler. The results were disappointing; it was difficult to maintain sustained combustion even when large quantities of supplemental fuel were used. Combustion efficiency was poor, around 60 percent. The results suggest that the rotary kiln boiler, as designed, is ill-suited with respect to low-grade, hard to burn solid fuels, such as anthracite culm. Indeed, data from combustion of bituminous coal in the PEDCO unit suggest that with respect to coal in general, the rotary kiln boiler appears inferior to the circulating fluid bed boiler.

  9. Drying firewood in a temporary solar kiln: a case study. Forest Service research note

    SciTech Connect

    Sampson, G.R.; Gasbarro, A.F.

    1986-08-01

    A pilot study was undertaken to determine drying rates for small-diameter, unsplit paper birch firewood that was dried: (1) in a conventional top-covered pile; (2) in a simple, temporary solar kiln; and (3) in tree length. Drying rates were the same for firewood piles whether they were in the temporary kiln or only covered on top to keep rain or snow from entering the pile. Trees that were severed at the stump and left to dry in tree length form, complete with branches and leaves, however, dried slower than firewood cut to length, stacked and top-covered or placed in the temporary solar kiln.

  10. Substitution of oil by hogged fuel in a kraft process lime sludge kiln

    SciTech Connect

    Rowe, I.G.

    1984-02-01

    Hogged fuel, typically at 55% moisture content, was combusted in a wet-cell burner and the flue gases applied to a lime sludge kiln. Up to 78% oil substitution was achieved, consistent with satisfactory lime quality and availability. Specific energy consumption was high because heat transfer was less efficient. Computer simulation techniques were used to develop parameter profiles throughout the kiln and to predict optimal performance. Optimized kiln conversion was shown to be economically advantageous if hogged fuel is available for $7.00 per cubic meter or less, assuming an oil price of $30/bbl ($0.189/l).

  11. Evaluation of internal alpha-particle radiation exposure and subsequent fertility among a cohort of women formerly employed in the radium dial industry

    SciTech Connect

    Schieve, L.A.; Davis, F.; Freels, S.

    1997-02-01

    This study examined the effect of internal exposure to {alpha}-particle radiation on subsequent fertility among women employed in radium dial industry prior to 1930, when appreciable amounts of radium were often ingested through the practice of pointing the paint brush with the lips. The analysis was limited to women for whom a radium body burden measurement had been obtained and who were married prior to age 45 (n = 603). Internal radiation dose to the ovary was calculated based on initial intakes of radium-226 and radium-228, average ovarian mass, number and energy of {alpha} particles emitted, fraction of energy absorbed within the ovary, effective retention integrals and estimated photon irradiation. Time between marriage and pregnancy, number of pregnancies and number of live births served as surrogates for fertility. Radiation appeared to have no effect on fertility at estimated cumulative ovarian dose equivalents below 5 Sv; above this dose, however, statistically significant declines in both number of pregnancies and live births were observed. These trends persisted after multivariable adjustment for potential confounding variables and after exclusion of subjects contributing a potential classification or selection bias to the study. Additionally, the high-dose group experienced fewer live births than would have been expected based on population rates. There were no differences in time to first pregnancy between high- and low-dose groups. These results are consistent with earlier studies of {gamma}-ray exposures and suggest that exposure to high doses of radiation from internally deposited radium reduces fertility rather than inducing sterility. 42 refs., 5 tabs.

  12. Solidification of cement kiln dust using sulfur binder.

    PubMed

    Mohamed, Abdel-Mohsen O; El Gamal, Maisa M

    2011-08-30

    The present study aims to offer a new methodology for consuming two industrial wastes; sulfur, from petroleum and natural gas industries, and cement kiln dust (CKD), from Portland cement industries, in construction industry. Sulfur solidified cement kiln dust material (SSCKDM) was manufactured by mixing molten sulfur, treated sulfur, CKD and sand at a controlled temperature in excess of 120°C. The hot mixture was subsequently cast and shaped into the desired mold and was then allowed to solidify at a specified cooling rate. Solidified materials were immersed for time periods up to 28 days in distilled water at different temperatures of 25 and 60°C, sea water, and acidic and basic universal buffer solutions of pH4 and pH9, respectively. Solidified material performance as function of time and type of aqueous solution exposed to was evaluated in view of compressive strength variations and leachability of metal and heavy metal ions. The results indicated that the solidified articles exhibit homogenous and compact internal microstructure with excellent mechanical properties. However, it showed durability problem upon exposure to aqueous solution environments due to the initial chemical composition of the CKD, whose leached test showed release of relatively high amounts of sulfates and alkali metals. Durability of SSCKDM articles in relation to strength reduction and crack formations control was improved by addition of glass fiber while, the use of anti-leaching agent such as anhydrous sodium sulfide resulted in reduction of leached heavy metals without any measurable decrease in leached amounts of alkali metals and anions from the solidified matrix. Furthermore, based on leachability index method of calculation, potential chemical mobility of metal and heavy metal ions from the solidified matrix was characterized as medium.

  13. Insulation performance data and assessment procedures for steam kiln energy conservation investments

    SciTech Connect

    Zaccor, J.V.

    1980-09-01

    For a demonstration project, the costs and benefits of insulating concrete block curing kilns to isolate the kiln thermal mass from the curing cycle are determined. Data were developed on service life of FOAMGLAS insulation, the effect of Johnson burners on the insulation and mounting, performance of an alternative insulation (a rapidly installed, spray-on polyurethane foam), and a simple incentive to promote implementation of industrial energy conservation concepts. Data are tabulated and compared for the FOAMGLAS and CPR 480 polyurethane insulations. Specific studies of insulation that was installed on inside surfaces of kilns to lock the kiln-mass out of the curing cycle are given for Blocklite plant in California, the Ameron pipe plant in California, and the Superlite plant in Phoenix, Arizona. (MCW)

  14. A COMPARISON OF IN-SITU VITRIFICATION AND ROTARY KILN INCINERATION FOR SOILS TREATMENT

    EPA Science Inventory

    In the hazardous waste community, the term "thermal destruction" is a catch-all phrase that broadly refers to high temperature destruction of hazardous contaminants. ncluded in the thermal destruction category are treatment technologies such as rotary kiln incineration, fluidized...

  15. Combustion efficiency and hydrocarbon emissions from charcoal production kilns in the tropics

    SciTech Connect

    Ward, D.E.; Hao, W.M.; Babbitt, R.E.

    1995-12-01

    Charcoal is one of the major energy resources in tropical countries. We investigate the combustion processes in charcoal production kilns in Zambia and Brazil. The Zambian kilns were made of earth and there was sufficient air for combustion inside the kilns. The Brazilian kilns were made of bricks which limited the available oxygen. The combustion efficiency and the concentrations of CO{sub 2}, CO, CH{sub 4}, C{sub 2}-C{sub 6} alkanes and alkenes, and aromatic compounds produced were monitored throughout the combustion processes. The contributions of charcoal production processes to the atmospheric sources of these gases were estimated. The strategies for improving charcoal yield and reducing emissions of carbon-containing compounds are discussed.

  16. Detection of hidden pre-industrial charcoal kilns by high-resolution LIDAR

    NASA Astrophysics Data System (ADS)

    Raab, Thomas; Raab, Alexandra; Nicolay, Alexander; Takla, Melanie; Rösler, Horst; Bönisch, Eberhard

    2013-04-01

    Over the last decade, systematic archaeological excavations in the open-cast mine Jänschwalde (Brandenburg, Germany) have revealed one of the largest, archaeologically excavated pre-industrial charcoal production area in Central Europe. Many of the charcoal kiln relics are easy to detect by survey as they lie close to the surface and charcoal pieces hint on their existence. In the excavations the remains of the charcoal kilns are distinct, black circles in the light-coloured sands. To date, in the former Königlich-Taubendorfer Forst c. 800 remains of charcoal hearths have been excavated and documented by archaeologists in an area of about 20 km2. Further c. 300 charcoal hearths are prospected by survey. Unfortunately, the spatial information about the charcoal kiln sites in Lower Lusatia (and elsewhere) is incomplete since we only have data from the archaeological excavation and prospection in the directly affected mining district. To fill this gap, we decided to test the applicability of Airborne Laser Scanning (ALS) data for charcoal kiln prospection. The particularly improved quality of the recent high-resolution light detection and ranging (LIDAR) data enabled the computer-aided detection of charcoal kilns and their evaluation using a geographical information system (GIS). Following data processing, the charcoal kilns are visible as buttons-like shapes in the shaded-relief maps (SRM). The characteristic shapes arise because the kiln plates are some centimetres to decimetres higher than the ditches around them. Numerous ground checks confirmed the applicability of the prospection by ALS data. But, we also assume that c. 10% of the charcoal kilns remain unidentified. A 26.6 km2 study area in the Tauerscher Forst, a forest about 10 km northwest of the open-cast mine Jänschwalde, was selected for prospection using a 1 m resolution ALS data set from the year 2011. Today, the area is forested with pine, and no archaeological excavation has been carried out so far

  17. Physicochemical characterization of cement kiln dust for potential reuse in acidic wastewater treatment.

    PubMed

    Mackie, A; Boilard, S; Walsh, M E; Lake, C B

    2010-01-15

    Cement kiln dust (CKD) is a fine-grained material produced during the manufacture of cement. Current reuse options are limited and the bulk of CKD not reused in the cement manufacturing process is sent to landfills or stored on-site. Due to the calcium oxide (CaO) content of CKD, it has the potential to be used as a replacement for lime in treating acidic wastewaters such as acid rock drainage (ARD). This paper outlines the results of an examination of the physical and chemical properties of CKD samples collected from six cement plants. The CKD samples were analyzed for major oxides using X-ray diffraction (XRD), available lime, specific surface area, particle size, and morphology using scanning electron microscope (SEM) and compared with a commercial quicklime product. Conductivity, pH, and calcium concentrations of slaked CKD and quicklime solutions were used as indicators of reactivity of the CKD. Slaking of two of the CKD samples with the highest free lime contents (e.g., 34 and 37% free CaO) gave elevated pH values statistically comparable to those of the commercial quicklime sample that was characterized as having 87% available CaO. Acid neutralization trials indicate that even CKD samples with low free lime contents could be effective at neutralizing acidic wastewaters.

  18. Field investigation of the temperature distribution in a commercial hazardous waste slagging rotary kiln

    SciTech Connect

    Veranth, J.M.; Gao, D.; Silcox, G.D.

    1996-10-01

    Gas and bed temperatures were studied in a 4.4 m by 12 m, co-current flow, slagging rotary kiln at a commercial hazardous waste incinerator. The visual observations used by the kiln operators to control the process are described. These observations were quantified using thermocouples, radiation pyrometers, and phase-change indicators. The objectives were to estimate the peak bed temperature and compare this to measurements at the kiln exit. The maximum bed temperature occurs toward the middle of this type of kiln and not at the discharge. The slag melting temperature and test pellets with known melting points indicate that the peak bed temperature can be 100-300 K higher than the kiln exit temperature reported by the permanent instruments at this facility. Both broad-band radiation pyrometers and thermocouples give a qualitative temperature indication that can be used for process control, but the readings depend on the sensor locations relative to the incompletely mixed air and combustion products. Two-color radiation pyrometer measurements of surface temperature near the kiln exit are higher than the actual temperature due to reflected radiation. 7 refs., 5 figs., 5 tabs.

  19. Three-dimensional detailed numerical model of a field-scale rotary kiln incinerator

    SciTech Connect

    Leger, C.B.; Cundy, V.A.; Sterling, A.M. )

    1993-04-01

    A detailed three-dimensional numerical model of baseline (support burners only) operation in a rotary kiln incinerator is presented. The focus of this model is on gas-phase fluid mechanics, neglecting solid waste combustion and radiative heat transfer. The model is compared to experimental data, and although relatively crude, it demonstrates remarkably good qualitative and quantitative predictive capability. The model demonstrates that thermal buoyancy is the cause of observed vertical stratification near the exit of the modeled kiln. The model also suggests that the addition of turbulence mixing air actually increases the degree of stratification rather than augmenting mixing, as had been previously suggested. Elucidating the mechanism by which this occurs has resulted in a reinterpretation of the experimental data. The model also suggests that there is probably a zone of recirculation across the kiln exit plane. A parametric study using the model shows that the location and quantity of leak air into the kiln have a major influence on the flow inside the kiln. The study suggests that preheating turbulence air may have little effect on gas-phase mixing. Overall, this modeling study has demonstrated that a relatively simple numerical model of a rotary kiln incinerator can provide valuable insight into the process, especially when used in conjunction with experimental data. 21 refs., 17 figs., 3 tabs.

  20. New R-SiC extends service life in kiln furniture

    SciTech Connect

    Sonntag, A.

    1997-11-01

    Silicon carbide kiln furniture systems are an essential part of modern high-temperature technology. SiC ceramics have exceptional high-temperature stability and thermal shock resistance., They show no plastic deformation (creep) under mechanical load and maintain their geometry after each high-temperature cycle. Therefore, various new kiln systems with light and open setting patterns can be realized where more fired goods can be produced with less kiln furniture ballast and within shorter firing cycles. The fast-firing technology of porcelain is an opportunity for new SiC kiln furniture ceramics. The new SiC ceramic systems available include: (1) recrystallized SiC (R-SiC); (2) silicon-infiltrated reaction-bonded SiC (SiSiC); and (3) nitride-bonded SiC (NSiC). The new SiC ceramics have an important production criterion in common. They show practically no shrinkage during production. This is important for the manufacture of large shapes, such as beams, rollers and setter plates, as well as tailored geometries that allow light and open kiln furniture construction. Because of the extraordinarily high thermal shock resistance, high strength and high-temperature creep stability of these SiC ceramics, delicate and precise kiln furniture configurations have been introduced. One application is the fast firing of tableware with automatic setting robots.

  1. Polychlorinated dibenzo(p)dioxin and furan (PCDD/F) congener profiles in cement kiln emissions and impacts.

    PubMed

    Ames, Michael; Zemba, Stephen; Green, Laura; Botelho, Maria João; Gossman, David; Linkov, Igor; Palma-Oliveira, José

    2012-03-01

    Cement kilns are known to emit polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs; "dioxins"), but estimates of the amounts and patterns of these emissions vary widely. These variations may stem from a combination of factors, including the design and operating conditions of the kiln, and the fuels and raw materials fed into the kiln. The goal of this study was to examine the patterns of dioxin emissions in a large set of stack-tests at two Portland cement kilns in Portugal that use a variety of fuels. A total of 152 stack-tests provided data on PCDD/F congener concentrations during which the kilns combusted a varied mix of fuels, including petroleum coke, coal, various "special" supplemental fuels, and refinery distillation ends, which are classified as hazardous wastes. The use of coal to fuel the kilns was found to generate significantly different emission-profiles relative to the use of petroleum coke, but the addition of hazardous wastes as a supplemental fuel did not significantly alter profiles. All of the kiln emission profiles were found to differ markedly from profiles in ambient air. However, the small absolute dioxin emission rates from the kilns suggested that kiln impacts would not be detectable via ambient air monitoring, even in rural settings.

  2. [Atmospheric emission of PCDD/Fs from modern dry processing cement kilns with preheating in the southwest area, China].

    PubMed

    Zhang, Xiao-Ling; Lu, Yi; Jian, Chuan; Guo, Zhi-Shun; Zhu, Ming-Ji; Deng, Li; Sun, Jing; Zhang, Qin

    2014-01-01

    Six cement kilns were measured for emissions of PCDD/Fs in the Southwest Area, China. The results indicated that the emission levels of PCDD/Fs were 0.0029-0.0062 ng-m(-3) (Average, 0.0043 ng X m(-3)) from cement kilns which did not burn solid waste, and 0.028 ng X m(-3) from co-processing sewage sludge in cement kiln. The levels of PCDD/Fs emissions from cement manufacturing in the Southwest Area were significantly below the national emissions standard (0.1 ng x m(-3)). Emission factors of PCDD/Fs from the six cement kilns varied between 0.0089 and 0.084 microg x t(-1) cement, which were near or below the lowest emission factor reported by UNEP in 2005. Moreover, the emission factor of PCDD/Fs from co-processing sewage sludge in cement kiln was 7.6 times of the average factors from the other five cement kilns. Moreover,congener distribution of PCDD/F in stack gas from the two types of cement kilns was very different. The results showed that modern dry process cement kilns with preheating have lower emissions of PCDD/Fs. This suggested that the product of co-processing solid waste in cement kilns should be largely enhanced in China in future.

  3. Study on the property of the production for Fengdongyan kiln in Early Ming dynasty by INAA and EDXRF

    NASA Astrophysics Data System (ADS)

    Li, L.; Huang, Y.; Sun, H. Y.; Yan, L. T.; Feng, S. L.; Xu, Q.; Feng, X. Q.

    2016-08-01

    A lot of official wares carved "Guan" or the dragon patterns were excavated on the strata of Ming dynasty of the Fengdongyan kiln site at Dayao County. The imperial porcelain was fired in Hongwu and Yongle eras. However, the emergence of this imperial porcelain has triggered academic debate about the property of Fengdongyan kiln in the Early Ming dynasty. Based on the differences of the official kiln management, some scholars have determined that the property of the production for this kiln was the civilian kiln. According to the historical textural records and typology, others preliminary confirmed that Fengdongyan kiln was the official kiln. In this paper, the elemental compositions of body and glaze in imperial and civilian porcelain are study by INAA and EDXRF for determining the property of the production for this kiln in Early Ming dynasty. After the processing of experimental data by geochemical analysis and principal component analysis, the result show that the raw materials for making body and glaze in imperial porcelain are similar with those of the civilian porcelain and the degrees of elutriation for body can be slightly different in HW-M period of Ming dynasty. The analytical results support the view that the Fengdongyan kiln is civilian not official.

  4. Analysis of elemental composition of porcelains unearthed from Waguantan kiln site by PIXE-RBS

    NASA Astrophysics Data System (ADS)

    Zhou, Z.; Zhang, K.; Xia, C. D.; Liu, M. T.; Zhu, J. J.; An, Z.; Bai, B.

    2015-03-01

    A method combining proton-induced X-ray emission spectrometry (PIXE) and Rutherford backscattering spectrometry (RBS) was used to determine the composition of 61 porcelain shards from the Yuan Dynasty (1271-1368 A.D.) unearthed from the Waguantan kiln site at Tianzhu County in Guizhou Province, China. Based on our previous experimental setup, an electron gun device with a LaB6 crystal cathode was installed to solve the problem created when the incident proton beams generated electric charge accumulations on the surfaces of the insulating porcelain samples, which induced a large bremsstrahlung background. The use of the electron gun has largely eliminated the large bremsstrahlung background and has therefore improved the detection limits for elements, especially for trace elements, and made it possible to determine the origin of the porcelains based on the trace elements. Major and trace elemental compositions of the porcelain bodies and glazes measured by PIXE and RBS were analyzed by the factor analysis method. The factor analysis showed that a few pieces of porcelain with a style similar to the porcelain of the Longquan kiln among the unearthed porcelains from the Waguantan kiln site did not have obvious differences in elemental compositions from other remaining porcelains unearthed from the Waguantan kiln site, indicating that the pieces of unearthed porcelain with the Longquan kiln style did in fact belong to the product fired locally by imitating the model of the Longquan celadon with local raw materials. This result therefore indicated that the Longquan kiln technology that originated from the Five Dynasties (907-960 A.D.) had been propagated to the Waguantan kiln site of Guizhou Province in the Yuan Dynasty.

  5. Zeolite synthesis from fly ash and cement kiln dust

    SciTech Connect

    Grutzeck, M.W.

    1996-12-31

    Zeolites added to portland cement paste normally undergo a pozzolanic reaction. However, if the composition of the cement is modified by blending it with fly ash, the calcium silicate hydrate (C-S-H) that forms has a low CaO/SiO{sub 2} ratio which allows it to coexist with a zeolite. In fact, if one adds alkali to the system, it then becomes possible to nucleate and grow a zeolitic phase with C-S-H. Normally zeolites that form from fly ash and NaOH include NaP-1 and analcime. But when the fly ash and NaOH are mixed with cement kiln dust, cancrinite-like phases and tobermorite form instead. This implies that a zeolite-containing monolith could be produced that would exhibit both the cation-exchange and adsorptive properties of zeolites while retaining the characteristic strength and ease of use attributable to cement based materials. These composites show promise as a new class of inexpensive cation exchange and/or chemical adsorbents that can be used for large scale applications.

  6. Thermal treatment of medical waste in a rotary kiln.

    PubMed

    Bujak, J

    2015-10-01

    This paper presents the results of a study of an experimental system with thermal treatment (incineration) of medical waste conducted at a large complex of hospital facilities. The studies were conducted for a period of one month. The processing system was analysed in terms of the energy, environmental and economic aspects. A rotary combustion chamber was designed and built with the strictly assumed length to inner diameter ratio of 4:1. In terms of energy, the temperature distribution was tested in the rotary kiln, secondary combustion (afterburner) chamber and heat recovery system. Calorific value of medical waste was 25.0 MJ/kg and the thermal efficiency of the entire system equalled 66.8%. Next, measurements of the pollutant emissions into the atmosphere were performed. Due to the nature of the disposed waste, particular attention was paid to the one-minute average values of carbon oxide and volatile organic compounds as well as hydrochloride, hydrogen fluoride, sulphur dioxide and total dust. Maximum content of non-oxidized organic compounds in slag and bottom ash were also verified during the analyses. The best rotary speed for the combustion chamber was selected to obtain proper afterburning of the bottom slag. Total organic carbon content was 2.9%. The test results were used to determine the basic economic indicators of the test system for evaluating the profitability of its construction. Simple payback time (SPB) for capital expenditures on the implementation of the project was 4 years.

  7. Carbon dioxide sequestration in cement kiln dust through mineral carbonation

    SciTech Connect

    Deborah N. Huntzinger; John S. Gierke; S. Komar Kawatra; Timothy C. Eisele; Lawrence L. Sutter

    2009-03-15

    Carbon sequestration through the formation of carbonates is a potential means to reduce CO{sub 2} emissions. Alkaline industrial solid wastes typically have high mass fractions of reactive oxides that may not require preprocessing, making them an attractive source material for mineral carbonation. The degree of mineral carbonation achievable in cement kiln dust (CKD) under ambient temperatures and pressures was examined through a series of batch and column experiments. The overall extent and potential mechanisms and rate behavior of the carbonation process were assessed through a complementary set of analytical and empirical methods, including mass change, thermal analysis, and X-ray diffraction. The carbonation reactions were carried out primarily through the reaction of CO{sub 2} with Ca(OH){sub 2}, and CaCO{sub 3} was observed as the predominant carbonation product. A sequestration extent of over 60% was observed within 8 h of reaction without any modifications to the waste. Sequestration appears to follow unreacted core model theory where reaction kinetics are controlled by a first-order rate constant at early times; however, as carbonation progresses, the kinetics of the reaction are attenuated by the extent of the reaction due to diffusion control, with the extent of conversion never reaching completion. 35 refs., 3 figs., 1 tab.

  8. Carbon dioxide sequestration in cement kiln dust through mineral carbonation.

    PubMed

    Huntzinger, Deborah N; Gierke, John S; Kawatra, S Komar; Eisele, Timothy C; Sutter, Lawrence L

    2009-03-15

    Carbon sequestration through the formation of carbonates is a potential means to reduce CO2 emissions. Alkaline industrial solid wastes typically have high mass fractions of reactive oxides that may not require preprocessing, making them an attractive source material for mineral carbonation The degree of mineral carbonation achievable in cement kiln dust (CKD) underambienttemperatures and pressures was examined through a series of batch and column experiments. The overall extent and potential mechanisms and rate behavior of the carbonation process were assessed through a complementary set of analytical and empirical methods, including mass change, thermal analysis, and X-ray diffraction. The carbonation reactions were carried out primarily through the reaction of CO2 with Ca(OH)2, and CaCO3 was observed as the predominant carbonation product. A sequestration extent of over 60% was observed within 8 h of reaction without any modifications to the waste. Sequestration appears to follow unreacted core model theory where reaction kinetics are controlled by a first-order rate constant at early times; however, as carbonation progresses, the kinetics of the reaction are attenuated by the extent of the reaction due to diffusion control, with the extent of conversion never reaching completion.

  9. Archaeomagnetic dating in Greece: new directional results from two contemporaneous kilns

    NASA Astrophysics Data System (ADS)

    Tema, Evdokia

    2013-04-01

    Detailed archaeomagnetic study was carried out on a ceramic workshop excavated at Kato Achaia (Greece). Two ancient circular brick kilns were discovered during the works for the construction of a house at Parodos Papaflessa Street, in the center of Kato Achaia village. According to archaeological evidence, both kilns were part of a bigger ceramic workshop, probably used for the production of bricks or ceramics. Systematic archaeomagnetic sampling was carried out collecting 9 brick samples from the first kiln (KL3) and 12 brick samples from the second kiln (KL5). All samples were independently oriented in situ using a magnetic compass and an inclinometer. Systematic magnetic measurements have been carried out in order to determine the main magnetic carrier of the samples and to check their thermal stability. Isothermal remanent magnetization (IRM) experiments pointed to magnetite and/or Ti-magnetite as the main magnetic minerals in most of the samples. These results are also confirmed by the thermal demagnetization of the three IRM components curves that in almost all cases show the dominance of the magnetically soft fraction (< 0.1 T). Standard archaeomagnetic procedures have been used to determine the archaeomagnetic direction registered by the bricks during the kilns last firings. Stepwise thermal demagnetization procedures reveal a single-component, stable remanent magnetization. The direction of the Characteristic Remanent Magnetization (ChRM) has been obtained from principal component analysis and the kilns mean directions were calculated using the Fisher statistics. The archaeomagnetic ages of both kilns have been obtained using the most recent developments in data elaboration and were calculated after comparison of the kilns archaeomagnetic parameters with the declination and inclination reference curves produced by the SHA.DIF.3K European regional geomagnetic field model. Dating results are in very good agreement with archaeological evidence of the site and

  10. 40 CFR Table 7 to Subpart Cccc of... - Emission Limitations for Waste-burning Kilns That Commenced Construction After June 4, 2010, or...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Kilns That Commenced Construction After June 4, 2010, or Reconstruction or Modification After August 7... to Subpart CCCC of Part 60—Emission Limitations for Waste-burning Kilns That Commenced Construction...). Use ICPMS for the analytical finish. Carbon monoxide 90 (long kilns)/190 (preheater/precalciner)...

  11. 40 CFR Table 7 to Subpart Cccc of... - Emission Limitations for Waste-Burning Kilns That Commenced Construction After June 4, 2010, or...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... Kilns That Commenced Construction After June 4, 2010, or Reconstruction or Modification After September... Waste-Burning Kilns That Commenced Construction After June 4, 2010, or Reconstruction or Modification... indefinitely. Table 7 to Subpart CCCC of Part 60—Emission Limitations for Waste-Burning Kilns That...

  12. 40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of... Kilns After May 20, 2011 Table 8 to Subpart DDDD of Part 60—Model Rule—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 For the air pollutant You must meet this...

  13. 40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of...—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 a For the air pollutant You must... (long kilns)/790 (preheater/precalciner) parts per million dry volume 3-run average (1 hour...

  14. 40 CFR Table 7 to Subpart Cccc of... - Emission Limitations for Waste-Burning Kilns That Commenced Construction After June 4, 2010, or...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Kilns That Commenced Construction After June 4, 2010, or Reconstruction or Modification After September... Waste-Burning Kilns That Commenced Construction After June 4, 2010, or Reconstruction or Modification... indefinitely. Table 7 to Subpart CCCC of Part 60—Emission Limitations for Waste-Burning Kilns That...

  15. 40 CFR Table 7 to Subpart Cccc of... - Emission Limitations for Waste-Burning Kilns That Commenced Construction After June 4, 2010, or...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Kilns That Commenced Construction After June 4, 2010, or Reconstruction or Modification After September..., Table 7 Table 7 to Subpart CCCC of Part 60—Emission Limitations for Waste-Burning Kilns That Commenced... limit. b NOX limits for new waste-burning kilns based on data for best-performing similar...

  16. 40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of...—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 a For the air pollutant You must... (long kilns)/790 (preheater/precalciner) parts per million dry volume 3-run average (1 hour...

  17. 40 CFR 63.1345 - Emissions limits for affected sources other than kilns; clinker coolers; new and reconstructed...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 12 2013-07-01 2013-07-01 false Emissions limits for affected sources other than kilns; clinker coolers; new and reconstructed raw material dryers. 63.1345 Section 63.1345... and Operating Limits § 63.1345 Emissions limits for affected sources other than kilns; clinker...

  18. Antioxidant enzymes status and reproductive health of adult male workers exposed to brick kiln pollutants in Pakistan.

    PubMed

    Jahan, Sarwat; Falah, Samreen; Ullah, Hizb; Ullah, Asad; Rauf, Naveed

    2016-07-01

    The present study was designed to study the effect of brick kilns emissions on the reproductive health and biochemical status of brick kiln workers and people living in the area near brick kilns. Body mass index (BMI) was significantly reduced in brick makers, carriers, and bakers compared to the control. Red blood cells count and hematocrit (%) were significantly high in brick bakers while MCH was significantly reduced in brick makers and brick bakers. Heavy metals (lead, cadmium, and chromium) concentration in whole blood of the brick kiln workers were significantly higher as compared to the control. Antioxidant enzymes (CAT, SOD, POD, GSH, and GR) were significantly reduced in brick kiln workers as compared to the control while TBARS level were significantly high in brick bakers as compared to the control. Plasma leutinizing hormone (LH) was significantly high in brick bakers while testosterone concentrations were significantly reduced in brick makers, carriers, and bakers. The present study shows that brick kiln workers and people living in the brick kiln vicinity are exposed to heavy metals and other pollutants that is a serious threat to their health. Alternate technology is needed to be developed and brick kilns should be replaced.

  19. 40 CFR 63.1345 - Emissions limits for affected sources other than kilns; clinker coolers; new and reconstructed...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 12 2014-07-01 2014-07-01 false Emissions limits for affected sources other than kilns; clinker coolers; new and reconstructed raw material dryers. 63.1345 Section 63.1345... and Operating Limits § 63.1345 Emissions limits for affected sources other than kilns; clinker...

  20. GREENHOUSE GASES FROM SMALL-SCALE COMBUSTION DEVICES IN DEVELOPING COUNTRIES, CHARCOAL-MAKING KILNS IN THAILAND

    EPA Science Inventory

    The report gives results of measurements of airborne emissions, during typical operating conditions, from charcoal-making kilns commonly used in the developing world. The kilns tested were of five types: brick beehive, mud beehive, earth mound, rice husk mound, and single (oil) d...

  1. 40 CFR 63.1343 - What standards apply to my kilns, clinker coolers, raw material dryers, and open clinker storage...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., clinker coolers, raw material dryers, and open clinker storage piles? 63.1343 Section 63.1343 Protection... associated with that kiln, clinker cooler, raw material dryer, and open clinker storage pile. All D/F, HCl... Limits § 63.1343 What standards apply to my kilns, clinker coolers, raw material dryers, and open...

  2. 40 CFR 63.1343 - What standards apply to my kilns, clinker coolers, raw material dryers, and open clinker storage...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., clinker coolers, raw material dryers, and open clinker storage piles? 63.1343 Section 63.1343 Protection... associated with that kiln, clinker cooler, raw material dryer, and open clinker storage pile. All D/F, HCl... Limits § 63.1343 What standards apply to my kilns, clinker coolers, raw material dryers, and open...

  3. Guidelines for Controlling Indoor Air Quality Problems Associated with Kilns, Copiers, and Welding in Schools. Technical Bulletin.

    ERIC Educational Resources Information Center

    Turner, Ronald W.; And Others

    Guidelines for controlling indoor air quality problems associated with kilns, copiers, and welding in schools are provided in this document. Individual sections on kilns, duplicating equipment, and welding operations contain information on the following: sources of contaminants; health effects; methods of control; ventilation strategies; and…

  4. Sustainability of cement kiln co-processing of wastes in India: a pilot study.

    PubMed

    Baidya, Rahul; Ghosh, Sadhan Kumar; Parlikar, Ulhas V

    2017-02-28

    Co-processing in cement kiln achieves effective utilization of the material and energy value present in the wastes, thereby conserving the natural resources by reducing the use of virgin material. In India, a number of multifolded initiatives have been taken that take into account the potential and volume of waste generation. This paper studies the factors which might influence the sustainability of co-processing of waste in cement kilns as a business model, considering the issues and challenges in the supply chain framework in India in view of the four canonical pillars of sustainability. A pilot study on co-processing was carried out in one of the cement plant in India to evaluate the environmental performance, economical performance, operational performance and social performance. The findings will help India and other developing countries to introduce effective supply chain management for co-processing while addressing the issues and challenges during co-processing of different waste streams in the cement kilns.

  5. Issues of operation during a trial burn at a wet process kiln

    SciTech Connect

    Ehinger, S.

    1997-12-31

    Trial burns are a requirement under Section 40 CFR 270.22 and 270.66(g), in order to obtain a Part B Permit, yet their usefulness when applied to a cement kiln has to be questioned. The very features that make a cement kiln so good at thermal destruction, that of very high temperatures and a long residence time, and the fact that they must stay at those temperatures in order to make their product, I believe greatly diminishes, if not eliminates the need for many trial burn requirements. In addition, for many kilns, operating at conditions required of a trial burn can have a very costly consequence. A trial burn is something that I believe both the regulation agency and the HWDF industry as a whole should work to modify and better adapt to each particular industry. It needs to be done.

  6. The 3Rs and cement kiln dust: Opportunities for reduction, reuse and recycling

    SciTech Connect

    Nisbet, M.

    1997-12-31

    Cement kiln dust (CKD) is a by-product of the cement manufacturing process. This material which is captured in cement kiln dust control equipment consists primarily of raw and partly calcined kiln feed. Factors which contribute to the generation of CKD are described. Cases of successful reduction of CKD generation are presented. Technologies for treating CKD so that it can be reused as a raw material for cement production are discussed. Applications where CKD can be used alone or with other by-products are also presented. Opportunities for developing new uses for CKD are identified and discussed in terms of the drivers behind such applications as well as the economic, technical and regulatory barriers to their development.

  7. Research on application of polynomial fitting technique in rotary kiln infrared temperature measurement system

    NASA Astrophysics Data System (ADS)

    Guo, Zhongyuan; Dai, Shaosheng; Liu, Jinsong; You, Changhui; Cheng, Yajun; Yu, Liangbing

    2016-11-01

    Aiming at the linear temperature compensation algorithm's disadvantage of temperature measurement error in rotary kiln infrared scanning temperature measurement process, this paper proposes a precise nonlinear cubic polynomial fitting temperature compensation algorithm. The proposed algorithm compensates the temperature values of scanning points on rotary kiln surface by following steps: Calculating temperature difference between the real temperature value of rotary kiln and temperature value measured by infrared scanning temperature measurement system; Fitting the temperature difference data with cubic polynomial; Using the obtained function to compensate temperature. Experimental result shows that compared with the usual linear temperature compensation algorithm, the accuracy of proposed algorithm has raised about 2.25 times when cubic polynomial is used.

  8. Research on position calibration method in infrared scanning temperature measurement system of rotary kiln

    NASA Astrophysics Data System (ADS)

    Dai, Shao-sheng; You, Chang-hui; Guo, Zhong-yuan; Cheng, Ya-jun; Yu, Liang-bing

    2016-11-01

    Aiming at the large error in the equal-interval locating method, a precise position calibration method is proposed. The proposed method improves the location measurement accuracy by introducing some feature temperature points to divide the rotary kiln into several segments, then the equal-interval locating method was applied to each segment, ultimately, a position calibration data more closing to the actual situation was got. The feature temperature points can be selected from the temperature points of kiln tyres or the highest temperature point and so on. Taking the practical application into consideration, the best result is obtained, when four feature temperature points was introduced to divide the rotary kiln into five segments. The experiment result shows that compared with the equal-interval method, the accuracy of the proposed method has raised about 5.6 times when four feature temperature points is used.

  9. Optimization of a wood dryer kiln using the mixed integer programming technique: A case study

    SciTech Connect

    Gustafsson, S.I.

    1999-07-01

    When wood is to be utilized as a raw material for furniture, buildings, etc., it must be dried from approximately 100% to 6% moisture content. This is achieved at least partly in a drying kiln. Heat for this purpose is provided by electrical means, or by steam from boilers fired with wood chips or oil. By making a close examination of monitored values from an actual drying kiln it has been possible to optimize the use of steam and electricity using the so called mixed integer programming technique. Owing to the operating schedule for the drying kiln it has been necessary to divide the drying process in very short time intervals, i.e., a number of minutes. Since a drying cycle takes about two or three weeks, a considerable mathematical problem is presented and this has to be solved.

  10. Effect of modification of the kilning regimen on levels of free ferulic acid and antioxidant activity in malt.

    PubMed

    Inns, Elizabeth L; Buggey, Lesley A; Booer, Christopher; Nursten, Harry E; Ames, Jennifer M

    2011-09-14

    Barley phenolic antioxidants change in response to the kilning regimen used to prepare malt. Green malt was kilned using four different regimens. There were no major differences among the finished malts in parameters routinely used by the malting industry, including, moisture, color, and diastatic activity. Ferulic acid esterase activity and free ferulic acid were higher in malts subjected to the coolest kilning regimen, but malt ethyl acetate extracts (containing ferulic acid) contributed only ∼5% of the total malt antioxidant activity. Finished malt from the hottest kilning regimen possessed the highest antioxidant activity, attributed to higher levels of Maillard reaction products. Modifying kilning conditions leads to changes in release of bound ferulic acid and antioxidant activity with potential beneficial effects on flavor stability in malt and beer.

  11. Application of the dynamic model of Saeman to an industrial rotary kiln incinerator: numerical and experimental results.

    PubMed

    Ndiaye, L G; Caillat, S; Chinnayya, A; Gambier, D; Baudoin, B

    2010-07-01

    In order to simulate granular materials structure in a rotary kiln under the steady-state regime, a mathematical model has been developed by Saeman (1951). This model enables the calculation of the bed profiles, the axial velocity and solids flow rate along the kiln. This model can be coupled with a thermochemical model, in the case of a reacting moving bed. This dynamic model was used to calculate the bed profile for an industrial size kiln and the model projections were validated by measurements in a 4 m diameter by 16 m long industrial rotary kiln. The effect of rotation speed under solids bed profile and the effect of the feed rate under filling degree were established. On the basis of the calculations and the experimental results a phenomenological relation for the residence time estimation was proposed for the rotary kiln.

  12. Multi-disciplinary dating of a baked clay kiln excavated at Chieri, Northern Italy

    NASA Astrophysics Data System (ADS)

    Tema, Evdokia; Fantino, Fulvio; Ferrara, Enzo; Lo Giudice, Alessandro; Re, Alessandro; Barello, Federico; Vella, Silvia; Cirillo, Luigi; Gulmini, Monica

    2014-05-01

    A combined archaeological, archaeomagnetic and thermoluminescence study has been carried out on a rescue excavation kiln, discovered at Chieri, Northern Italy. Rock magnetic experiments indicate the dominance of a low coercivity magnetic phase, such as magnetite and/or Ti-magnetite as the main carrier of the remanent magnetization. Stepwise thermal demagnetization experiments generally show a stable characteristic remanent magnetization (ChRM). The mean archaeomagnetic direction, calculated from 17 independently oriented samples, is D=18.2o, I=66.8o with α95=2.6o and k=184. Archaeomagnetic dating of the kiln has been obtained after comparison of the kiln's ChRM direction with the reference curves produced by the SHA.DIF.3K European regional geomagnetic field model. Independent dating of the kiln has also been obtained from thermoluminescence (TL) study of two baked clay samples coming from the kiln's walls. The environmental dose has been measured in situ using field dosimeters. Accurate TL procedures have been followed for the calculation of annual dose and eventually the TL age. The combination of the archaeological evidence, archaeomagnetic and TL datings suggest that the last usage of the kiln occurred around the 17th century AD. Comparison of the results obtained from the different methods shows the relevant potential of these techniques on dating of baked clay artefacts; yet it also highlights the range of uncertainty sources affecting measurements, related to the samples and/or to the environment, and the utility of dating cross-checking for obtaining reliable dates.

  13. Mathematical modeling of pneumatic char injection in a direct reduction rotary kiln

    SciTech Connect

    Ramakrishnan, V.; Sai, P.S.T.

    1999-10-01

    A one-dimensional steady-state mathematical model is proposed for direct reduction process in rotary kilns akin to the SL/RN process. The model takes into account pneumatic coal char injection from the discharge end of the kiln to supplement the heat availability. The model is based on material and energy conservation principles, and the empirical equations for kinetics and heat transfer are obtained from the literature. Predictions are carried out for both iron oxide reduction and ilmenite beneficiation processes. Improvement in the performance was predicted with pneumatic char injection.

  14. Research on high precision equal-angle scanning method in rotary kiln temperature measurement system

    NASA Astrophysics Data System (ADS)

    Dai, Shaosheng; Guo, Zhongyuan; You, Changhui; Liu, Jinsong; Cheng, Yang; Tang, Huaming

    2016-05-01

    Aiming at traditional horizontal equal-angle scanning method's disadvantage of measurement error, a high precision equal-angle scanning method is proposed, the proposed method establishes a tilt scanning model by the following steps: introducing height variable, precisely calculating the viewing angle, building scanning model. The model is used to calculate scanning position on rotary kiln's surface, which helps to locate and track temperature variation. The experiment shows that the proposed method can effectively improve the precision of temperature spots' location on the rotary kiln surface.

  15. Regulating the combustion temperature of the fuel in kilns for firing electrical porcelain

    SciTech Connect

    Etingen, L.A.; Koren, M.G.; Tishkevich, L.B.

    1986-11-01

    It can be assumed that the use of ballasted air in burner devices of kilns working with natural gas and equipped with low-pressure burners will give an increase in the consumption and pressure of the ballasted air compared with pure (nonballasted) air; there should be an improvement in the introduction of the fuel, its mixing conditions, and the combustion conditions. The proposed method of regulating the temperature in kilns can be used in other industries with similar heattreatment conditions for the goods.

  16. Evaluation of hazardous-waste incineration in an aggregate kiln: Florida Solite Corporation. Summary report

    SciTech Connect

    Day, D.R.; Cox, L.A.; Peters, J.A.

    1985-04-01

    Aggregate kiln incineration of chlorinated liquid organic waste was investigated in a one-week program at Florida Solite Company. POHCs (toluene, tetrachloroethylene, methyl ethyl ketone, and methyl isobutyl ketone) were monitored in waste and stack emissions. In addition, stack emissions were monitored for particulate matter, particulate trace metals, HCl, SO/sub 2/, and NOx. Process samples were collected and analyzed for trace metals and chloride. The destruction and removal efficiency of POHCs and the fate of trace metals and chloride ion in the kiln process were determined.

  17. Improving Dielectric Properties of PVDF Composites by Employing Surface Modified Strong Polarized BaTiO₃ Particles Derived by Molten Salt Method.

    PubMed

    Fu, Jing; Hou, Yudong; Zheng, Mupeng; Wei, Qiaoyi; Zhu, Mankang; Yan, Hui

    2015-11-11

    BaTiO3/polyvinylidene fluoride (BT/PVDF) is the extensive reported composite material for application in modern electric devices. However, there still exists some obstacles prohibiting the further improvement of dielectric performance, such as poor interfacial compatibility and low dielectric constant. Therefore, in depth study of the size dependent polarization and surface modification of BT particle is of technological importance in developing high performance BT/PVDF composites. Here, a facile molten-salt synthetic method has been applied to prepare different grain sized BT particles through tailoring the calcination temperature. The size dependent spontaneous polarizationof BT particle was thoroughly investigated by theoretical calculation based on powder X-ray diffraction Rietveld refinement data. The results revealed that 600 nm sized BT particles possess the strong polarization, ascribing to the ferroelectric size effect. Furthermore, the surface of optimal BT particles has been modified by water-soluble polyvinylprrolidone (PVP) agent, and the coated particles exhibited fine core-shell structure and homogeneous dispersion in the PVDF matrix. The dielectric constant of the resulted composites increased significantly, especially, the prepared composite with 40 vol % BT loading exhibited the largest dielectric constant (65, 25 °C, 1 kHz) compared with the literature values of BT/PVDF at the same concentration of filler. Moreover, the energy storage density of the composites with tailored structure was largely enhanced at the low electric field, showing promising application as dielectric material in energy storage device. Our work suggested that introduction of strong polarized ferroelectric particles with optimal size and construction of core-shell structured coated fillers by PVP in the PVDF matrix are efficacious in improving dielectric performance of composites. The demonstrated approach can also be applied to the design and preparation of other polymers

  18. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis

    PubMed Central

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070–c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula. PMID:26535583

  19. Stack and fugitive emissions of major air pollutants from typical brick kilns in China.

    PubMed

    Chen, Yuanchen; Du, Wei; Zhuo, Shaojie; Liu, Weijian; Liu, Yuanlong; Shen, Guofeng; Wu, Shuiping; Li, Jianjun; Zhou, Bianhong; Wang, Gehui; Zeng, Eddy Y; Cheng, Hefa; Liu, Wenxin; Tao, Shu

    2017-02-22

    Little information exists on emission factors (EFs, quantities of pollutants emitted per unit of fuel consumed) for brick kilns in China, although brick kilns are important emission sources of many air pollutants, and 45% of the world's bricks are produced in China. In this study, EFs of carbon dioxide (CO2), carbon monoxide (CO), sulfur dioxide (SO2), nitrogen oxides (NOx), particulate matters (PMs), black carbon (BC), organic carbon (OC), and polycyclic aromatic hydrocarbons (PAHs) for brick kilns were derived based on field measurements of a total of 18 brick kilns of major types in China. This was the first study to quantify EFs of both stack and fugitive sources based on a modified carbon balance method that was developed for this study. The EFs of most pollutants, especially the incomplete combustion products in fugitive emissions, were much higher than those for stack emissions, indicating a substantial underestimation of total emissions when leakage is not taken into consideration. This novel method can be applied to quantify emissions from other similar sources with both stack and fugitive emissions.

  20. Palaeointensity determination on an early medieval kiln from Switzerland and the effect of cooling rate

    NASA Astrophysics Data System (ADS)

    Donadini, F.; Kovacheva, M.; Kostadinova, M.; Hedley, I. G.; Pesonen, L. J.

    The archaeomagnetic intensity reference curve for Western Europe lacks data during the period from 600 to 1000 AD. Baked clay from the walls of a pottery kiln at Reinach (Switzerland), archaeologically dated to the beginning of the 9th century AD, and having a 14C date of 1250 ± 50 BP, was investigated in order to refine the ancient geomagnetic field intensity during this period. A previous study to test the suitability of the material has shown that the magnetic properties of the baked clay from this Reinach kiln are appropriate for an archaeomagnetic study, and furthermore an archaeomagnetic directional date agrees well with the 14C date. A series of palaeointensity measurements was carried out in Sofia (Bulgaria). Here we present the results obtained from the same material, as performed in Helsinki (Finland) using different techniques. The comparison of the results shows significant differences between the two datasets. Based on the literature data, the discrepancy can be explained in terms of the different cooling rates of the samples used during the experiments in the two laboratories. Nevertheless, the results show that the geomagnetic field intensity had a high mean value of 86.85 ± 1.49 μT when the kiln was last used. This observation is consistent with recent studies from France covering the period during which the Reinach kiln functioned.

  1. Characteristics of dioxin emissions from a Waelz plant with acid and basic kiln mode.

    PubMed

    Hung, Pao Chen; Chi, Kai Hsien; Chen, Mei Lien; Chang, Moo Been

    2012-01-30

    The concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were measured in the flue gas of a Waelz plant operated in acid and basic modes, respectively. To abate (PCDD/F) and other pollutants, the plant operates with a post-treatment of flue gases by activated carbon injection and subsequent filtration. Relatively high PCDD/F discharge by fly ashes is found with acid kiln mode of the Waelz process. Therefore, basic kiln mode of the Waelz process is investigated and compared in this plant. With the adsorbent injection rate of 7 kg/h (95 mg/Nm(3)), the PCDD/F concentration in stack gas was measured as 0.123 ng I-TEQ/Nm(3) in the basic operating mode. The added Ca(OH)(2) reacted with metal catalysts and HCl((g)) in the flue gas and thus effectively suppressed the formation of PCDD/Fs. PCDD/F concentrations in fly ashes sampled from the dust settling chamber, cyclone, primary filter and secondary filter in basic kiln mode were significantly lower than that in acid kiln mode. Total PCDD/F emission on the basis of treating one kg of electric arc furnace dust in the basic operation mode was 269 ng I-TEQ/kg EAF-dust treated which was significantly lower than that in acid mode (640 ng I-TEQ/kg EAF-dust treated).

  2. Test burn with PCB-oil in a local cement kiln in Sri Lanka.

    PubMed

    Karstensen, Kåre Helge; Mubarak, Azeez M; Gunadasa, H N; Wijagunasekara, Bandulasoma; Ratnayake, Niranjanie; Alwis, Ajith De; Fernando, Jayavilal

    2010-02-01

    The production and use of polychlorinated biphenyls (PCBs) have ceased and most developed countries have disposed off their stocks long time ago. PCBs can however still be found in the environment and one important source is accumulated stocks in developing countries. Sound treatment of PCB is costly and most developing countries do not have dedicated hazardous waste incinerators or non-combustion technologies available for domestic disposal and can usually not afford export. High temperature cement kilns have been used to treat organic hazardous wastes in developed countries for decades and shown to constitute a sound option if well managed and controlled. In contrast to dedicated hazardous waste incinerators and other treatment techniques, cement kilns are already in place in virtually every country and may constitute a treatment option. The objective of this study was therefore to carry out the first test burn with PCB-oil in a developing country cement kiln and to assess its feasibility and destruction performance. The 3 d test burn demonstrated that the Sri Lankan cement kiln was able to destroy PCB in an irreversible and environmental sound manner without causing any new formation of PCDD/PCDF or HCB. The destruction and removal efficiency (DRE) was better than 99.9999% at the highest PCB feeding rate.

  3. Emissions study of co-firing waste carpet in a rotary kiln.

    PubMed

    Lemieux, Paul; Stewart, Eric; Realff, Matthew; Mulholland, James A

    2004-01-01

    Post-consumer carpet represents a high volume, high energy content waste stream. As a fuel for co-firing in cement kilns, waste carpet, like waste tires, has potential advantages. Technological challenges to be addressed include assessing potential emissions, in particular NO emissions (from nylon fiber carpets), and optimizing the carpet feed system. This paper addresses the former. Results of pilot-scale rotary kiln experiments demonstrate the potential for using post-consumer waste carpet as a fuel in cement kilns. Continuous feeding of shredded carpet fiber and ground carpet backing, at rates of up to 30% of total energy input, resulted in combustion without transient puffs and with almost no increase in CO and other products of incomplete combustion as compared to kiln firing natural gas only. NO emissions increased with carpet waste co-firing due to the nitrogen content of nylon fiber. In these experiments with shredded fiber and finely ground backing, carpet nitrogen conversion to NO ranged from 3 to 8%. Conversion increased with enhanced mixing of the carpet material and air during combustion. Carpet preparation and feeding method are controlling factors in fuel N conversion.

  4. Cancer risk evaluation of brick kiln workers exposed to dust bound PAHs in Punjab province (Pakistan).

    PubMed

    Kamal, Atif; Malik, Riffat Naseem; Martellini, Tania; Cincinelli, Alessandra

    2014-09-15

    Principal objective of this study was to evaluate the health risks of brick kiln workers to dust bound PAHs exposure in Punjab province (Pakistan). To this aim, surface dust samples were collected from brick kiln units located in Chung Khurd (Lahore city), Gujranwala city and Sohra village (in the vicinity of Gujranwala). The highest ΣPAH levels were measured in the dust samples collected in Sohdra village (mean 2578 ng g(-1) d.w., range 302-6757 ng g(-1) d.w.) followed by Gujranwala city (mean 957, range 16.1-1963 ng g(-1) d.w.) and Chung Khurd (mean 882, range 692-1007 ng g(-1) d.w.). Source identification using diagnostic ratios and principal component analysis identified coal and wood combustion as the major PAHs sources. The cancer risk model (CR-Model 1) and the Incremental Lifetime Cancer Risk model (ILCR-Model 2) were used to evaluate the cancer risk assessment via ingestion, inhalation and dermal contact pathways. Both models suggested that brick kiln workers (including adults and children) were exposed to high-potential carcinogenic risk via both ingestion and dermal contact pathways during the brick making process. This study also emphasizes the need for pollution control in the brick kiln industry of Pakistan.

  5. The Earliest Chinese Proto-Porcelain Excavated from Kiln Sites: An Elemental Analysis.

    PubMed

    Li, Yu; Zhang, Bin; Cheng, Huansheng; Zheng, Jianming

    2015-01-01

    In June 2012, the Piaoshan kiln site was excavated in Huzhou, Zhejiang Province, which hitherto proved to be the earliest known Chinese proto-porcelain kiln. Judging from the decorative patterns of unearthed impressed stoneware and proto-porcelain sherds, the site was determined to date to the late Xia (c. 2070-c. 1600 BC), the first dynasty of China. Here, we report on proton-induced X-ray emission analyses of 118 proto-porcelain and 35 impressed stoneware sherds from Piaoshan and five subsequent kiln sites in the vicinity. Using principal components analysis on the major chemical compositions, we reveal the relationships between impressed stoneware and proto-porcelain samples from the six kiln sites. The sherds from different sites have distinctive chemical profiles. The results indicate that the raw materials were procured locally. We find a developmental tendency for early glazes towards mature calcium-based glaze. It is most likely that woody plant ashes with increased calcia-potash ratios were applied to the formula.

  6. Pulmonary dysfunctions, oxidative stress and DNA damage in brick kiln workers.

    PubMed

    Kaushik, R; Khaliq, F; Subramaneyaan, M; Ahmed, R S

    2012-11-01

    Brick kilns in the suburban areas in developing countries pose a big threat to the environment and hence the health of their workers and people residing around them. The present study was planned to assess the lung functions, oxidative stress parameters and DNA damage in brick kiln workers. A total of 31 male subjects working in brick kiln, and 32 age, sex and socioeconomic status matched controls were included in the study. The lung volumes, capacities and flow rates, namely, forced expiratory volume in first second (FEV(1)), forced vital capacity (FVC), FEV(1)/FVC, expiratory reserve volume, inspiratory capacity (IC), maximal expiratory flow when 50% of FVC is remaining to be expired, maximum voluntary ventilation, peak expiratory flow rate and vital capacity were significantly decreased in the brick kiln workers. Increased oxidative stress as evidenced by increased malonedialdehyde levels and reduced glutathione content, glutathione S-transferase activity and ferric reducing ability of plasma were observed in the study group when compared with controls. Our results indicate a significant correlation between oxidative stress parameters and pulmonary dysfunction, which may be due to silica-induced oxidative stress and resulting lung damage.

  7. The numerical modelling and process simulation for the fault diagnosis of rotary kiln incinerator.

    PubMed

    Roh, S D; Kim, S W; Cho, W S

    2001-10-01

    The numerical modelling and process simulation for the fault diagnosis of rotary kiln incinerator were accomplished. In the numerical modelling, two models applied to the modelling within the kiln are the combustion chamber model including the mass and energy balance equations for two combustion chambers and 3D thermal model. The combustion chamber model predicts temperature within the kiln, flue gas composition, flux and heat of combustion. Using the combustion chamber model and 3D thermal model, the production-rules for the process simulation can be obtained through interrelation analysis between control and operation variables. The process simulation of the kiln is operated with the production-rules for automatic operation. The process simulation aims to provide fundamental solutions to the problems in incineration process by introducing an online expert control system to provide an integrity in process control and management. Knowledge-based expert control systems use symbolic logic and heuristic rules to find solutions for various types of problems. It was implemented to be a hybrid intelligent expert control system by mutually connecting with the process control systems which has the capability of process diagnosis, analysis and control.

  8. Pyrolysis of Uinta Basin Oil Sands in fluidized bed and rotary kiln reactors

    SciTech Connect

    Nagpal, S.; Fletcher, J.V.; Hanson, F.V.

    1995-12-31

    A pilot-scale fluidized bed reactor (FBR) was used to pyrolyze the mined and crushed ore from the PR Spring oil sands deposit which is located in the Uinta Basin of Utah. Liquid yields of approximately 80 wt% of the bitumen fed to the reactor were obtained. This compares to 55-70 wt% obtained from smaller laboratory scale fluidized bed reactors and a pilot-scale rotary kiln. The product yields and distributions exhibited no discernable trends with reactor temperature or solids retention time. The liquid products obtained from the pilot-scale fluidized bed reactor were upgraded compared to the bitumen in terms of volatility, viscosity, molecular weight, and metals (Ni and V) content. The nitrogen and sulphur contents of the total liquid products were also reduced relative to the bitumen. A comparison of oil sands pyrolysis yields from a pilot scale FBR and a rotary kiln of the same diameter (15.2 cm) was made. Under similar pyrolysis conditions, the rotary kiln produced a slightly more upgraded product but at lower total liquid yields. Kinetic modeling of the various reactors indicates that the pilot-scale FBR product distributions may be explained using a simplified two-reaction scheme. It is proposed that secondary cracking is suppressed in the large diameter FBR due to elimination of slugging and the superior quality of fluidization in the reactor. More experimental studies with the rotary kiln and an economic evaluation will be required before concluding which reactor is preferred for the thermal recovery process.

  9. Evaluation of hazardous waste incineration in a lime kiln: Rockwell Lime Company. Final report

    SciTech Connect

    Day, D.R.; Cox, L.A.

    1984-08-01

    During a one-week test burn, hazardous waste was used as supplemental fuel and co-fired with petroleum coke in a lime kiln in eastern Wisconsin. Detailed sampling and analysis was conducted on the stack gas for principal organic hazardous constituents (POHCs), particulates, particulate metals, HCl, SO2, NOx, CO, and THC and on process streams for metals and chlorine. POHCs were also analyzed in the waste fuel. Sampling was conducted during three baseline and five waste fuel test burn days. The program objectives were to determine the destruction and removal efficiency (DRE) for each POHC, determine concentration of stack gas pollutants under baseline and waste fuel test burn conditions, determine the fate of chlorine, sulfur, and trace metals in the kiln process, and evaluate kiln performance when operating with hazardous waste as supplemental fuel. Results show average DRE's greater than 99.99 percent for each POHC and little change in pollutant emissions from baseline to waste fuel test conditions. In addition, material balance results show that 95 percent of chlorine enters the process from the limestone feed and the chlorine exits the kiln in the baghouse dust and lime product at 61 percent and 38 percent, respectively.

  10. Nitric oxide formation in an iron oxide pellet rotary kiln furnace.

    PubMed

    Davis, R A

    1998-01-01

    A one-dimensional numerical model was developed to simulate the effects of heat and mass transfer on the formation of oxides of nitrogen (NOx) in a rotary kiln furnace for iron oxide pellet induration. The modeled kiln has a length-to-diameter ratio of approximately seven. The principal mechanism of heat transfer is radiation from the flame, which was described by the net radiation method. The well known Zeldovich mechanism was used to predict thermal NOx generation. Temperature fluctuations in the vicinity of the flame were estimated with a clipped Gaussian probability density function. The thermal energy and mass balance model equations were solved numerically. The model is capable of predicting temperature profiles and NOx production rates in agreement with observed plant performance. The model was used to explore the effects of process changes on the total NOx formation in the kiln. It was concluded that the gas temperature as well as the partial pressure of oxygen in the process gases controls the rate of NOx formation. Lowering the temperature of the kiln gases by increasing the secondary air flow rates requires simultaneously decreasing the pellet production rate in order to maintain the pellet temperatures needed for blast furnace conditions.

  11. Osmolyte Concentration in Green and Kilned Malt as Indicators of Malt Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This research was conducted to test the hypothesis that osmolyte concentrations of green and/or kilned malts can be used as early indicators of finished malt quality. Barley seeds were steeped and germinated in a mircomalter for six days during which time samples were collected every 24 h. Green ...

  12. Profiles of polychlorinated biphenyls (PCBs) in cement kilns co-processing solid waste.

    PubMed

    Jin, Rong; Zhan, Jiayu; Liu, Guorui; Zhao, Yuyang; Zheng, Minghui; Yang, Lili; Wang, Mei

    2017-05-01

    Co-incineration of sewage sludge in cement kilns can be used for its disposal. In the present study, samples were collected from three cement production runs where sewage sludge and other wastes (e.g. municipal solid waste, waste acid and wet sewage sludge) were co-processed. The samples were analyzed for polychlorinated biphenyls (PCBs). The dioxin-like (dl)-PCB concentrations in the stack gases from run 1, 2, and 3 were 344.6, 548.7, and 104.3 pg m(-3), respectively. The toxic equivalency (TEQs) values for runs 1, 2, and 3 were 5.6, 8.9, and 0.7 pg TEQ Nm(-3), respectively. Calculation of net emissions for the three runs indicated that the co-incineration of other waste in addition to sewage sludge in cement kilns would not increase emission of the dl-PCBs. PCB concentrations in samples from the suspension boiler and humidifier tower, kiln-end bag filter, and cyclone preheater were much higher than those in samples from the kiln head area, indicating that these stages will be important for controlling PCB formation. Chlorinated biphenyl (CB)-77, CB-105 and CB-118 were the major dl-PCB congeners, CB-52, CB-101 were the major indicator PCB congeners, and tetra-CB to hexa-CB were the major homologues for the total input or output materials.

  13. Industry Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2012

    2012-01-01

    This article illustrates projected employment change by industry and industry sector over 2010-20 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment for which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  14. Industry Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2010

    2010-01-01

    This article illustrates projected employment change from an industry perspective over the 2008-2018 decade. Workers are grouped into an industry according to the type of good produced or service provided by the establishment in which they work. Industry employment projections are shown in terms of numeric change (growth or decline in the total…

  15. Design of Refractory Linings for Balanced Energy Efficiency, Uptime, and Capacity in Lime Kilns

    SciTech Connect

    Gorog, John Peter; Hemrick, James Gordon; Walker, Harold; Leary, William R; Ellis, Murray

    2014-01-01

    The rotary kilns used by the pulp and paper industry to regenerate lime in the Kraft process are very energy intensive. Throughout the 90 s, in response to increasing fuel prices, the industry used back up insulation in conjunction with the high alumina brick used to line the burning zones of their kilns. While this improved energy efficiency, the practice of installing insulating brick behind the working lining increased the inner wall temperatures. In the worst case, due to the increased temperatures, rapid brick failures occurred causing unscheduled outages and expensive repairs. Despite these issues, for the most part, the industry continued to use insulating refractory linings in that the energy savings were large enough to offset any increase in the cost of maintaining the refractory lining. Due to the dramatic decline in the price of natural gas in some areas combined with mounting pressures to increasing production of existing assets, over the last decade, many mills are focusing more on increasing the uptime of their kilns as opposed to energy savings. To this end, a growing number of mills are using basic (magnesia based) brick instead of high alumina brick to line the burning zone of the kiln since the lime mud does not react with these bricks at the operating temperatures of the burning zone of the kiln. In the extreme case, a few mills have chosen to install basic brick in the front end of the kiln running a length equivalent to 10 diameters. While the use of basic brick can increase the uptime of the kiln and reduce the cost to maintain the refractory lining, it does dramatically increase the heat losses resulting from the increased operating temperatures of the shell. Also, over long periods of time operating at these high temperatures, damage can occur in the shell. There are tradeoffs between energy efficiency, capacity and uptime. When fuel prices are very high, it makes sense to insulate the lining. When fuel prices are lower, trading some

  16. Full-vector archeomagnetic and rock-magnetic results from Portuguese kilns

    NASA Astrophysics Data System (ADS)

    Gomez-Paccard, Miriam; Tema, Evdokia; McIntosh, Gregg; Letaio, Manuela; Calado, Marco; Botelho, Paulo

    2014-05-01

    Despite the increase in archeomagnetic studies in the past few years, the number of reliable archeointensity data is still limited. At present Europe is the most widely covered region, although the variation in geomagnetic field intensity is not completely known for the last millennia and the occurrence and behaviour of various rapid geomagnetic field changes is under discussion. In this context, new high-reliable full-geomagnetic field vector determinations from unexplored regions are crucial in order to improve our knowledge of past geomagnetic field changes at regional scales. In Portugal, despite the rich cultural heritage and the abundance of archaeological excavations, archaeomagnetic research is still in its infancy. To our knowledge, up to now the only available directional data obtained from more or less well-dated materials come from the study of a Late Bronze Age vitrified wall close to the city of Serpa, southern Portugal, while only two more studies have been published including archaeointesity results from Portuguese pottery. We present here the first full-vector archeomagnetic results (declination, inclination and intensity) from two kilns excavated at two archaeological sites at Lisboa (Portugal). The first structure corresponds to the Largo das Alcaçarias Islamic pottery production workshop located in the eastern suburb Luxbona (current Alfama) and its abandonment has been dated as the 12th century AD. The second kiln was excavated in the Encosta Santana archeological medieval site and was abandoned during the 12th or 13th centuries AD according to archeological evidence. Detailed archaeomagnetic and rock magnetic studies have been carried out in order to determine the magnetic mineralogy and investigate the thermal stability of the phases carrying the archaeomagnetic signal. Both kilns exhibited thermally stability magnetic phases. The magnetic properties of the Largo kiln are dominated by a mixture of magnetite/cation-substituted magnetite and

  17. [Chemical composition and chromaticity characteristic of purple-gold glaze of Jingdezhen imperial kiln].

    PubMed

    Wu, Jun-Ming; Li, Qi-Jiang; Zhang, Mao-Lin; Ding, Yin-Zhong; Cao, Jian-Wen; Liu, Xiao-Jing

    2014-03-01

    Color glaze is one of the four famous traditional ceramics of Jingdezhen, especially for the products from Ming and Qing Dynasties' official kilns which have rich connotation of technology and culture. The chemical composition and chromaticity characteristic of glaze and body of purple-gold glaze samples from Jingdezhen Ming and Qing Dynasties' official kilns were analyzed by energy dispersive X ray fluorescence (EDXRF) and colorimeter. Preliminary study on the composition, formula and chromaticity characteristic of glaze of purple-gold glaze samples of different period was carried out and the intrinsic causes of ifferences were discussed. The result shows that the concentration of magnesium and calcium in purple-gold glaze is different from the other glazes in Jingdezhen in the same time, probably due to the addition of auburn or brown limestone which is rich in magnesium. The purple-gold glaze sample of Ming Dynasty is darker chiefly because the concentration of magnesium and calcium is higher than the sample of Ming Dynasty which led to iron crystal separated, reducing the brightness and glossiness of glaze. In addition, the body of purple-gold glaze samples from Jingdezhen Ming and Qing Dynasties' official kilns has the characteristics of high silicon and low aluminum and the molar ratio of silicon to aluminum of samples from Ming Dynasty to Qing Dynasty declined, showing that the concentration of kaolin of sample's body of Ming dynasty was increased. The result of this experiment fill deficiency in the ceramic science and technology research in our country about purple-gold glaze from Ming and Qing Dynasties' official kilns and provides scientific material for comprehensive understanding of porcelain marking technology and intrinsic value of Jingdezhen official kiln.

  18. Characterization, stability, and plant effects of kiln-produced wheat straw biochar.

    PubMed

    O'Toole, A; Knoth de Zarruk, K; Steffens, M; Rasse, D P

    2013-01-01

    Biochar is a promising technology for improving soil quality and sequestering C in the long term. Although modern pyrolysis technologies are being developed, kiln technologies often remain the most accessible method for biochar production. The objective of the present study was to assess biochar characteristics, stability in soil, and agronomic effects of a kiln-produced biochar. Wheat-straw biochar was produced in a double-barrel kiln and analyzed by solid-state C nuclear magneticresonance spectroscopy. Two experiments were conducted with biochar mixed into an Ap-horizon sandy loam. In the first experiment, CO efflux was monitored for 3 mo in plant-free soil columns across four treatments (0, 10, 50, and 100 Mg biochar ha). In the second experiment, ryegrass was grown in pots having received 17 and 54 Mg biochar ha combined with four N rates from 144 to 288 kg N ha. Our kiln method generated a wheat-straw biochar with carbon content composed of 92% of aromatic structures. Our results suggest that the biochar lost <0.16% C as CO over the 90-d incubation period. Biomass yields were not significantly modified by biochar treatments, except for a slight decrease at the 144 kg N ha rate. Foliar N concentrations were significantly reduced by biochar application. Biochar significantly increased soil water content; however, this increase did not result in increased biomass yield. In conclusion, our kiln-produced biochar was highly aromatic and appeared quite recalcitrant in soil but had no overall significant impact on ryegrass yields.

  19. Effects of bypass system on PCDD/F emission and chlorine circulation in cement kilns.

    PubMed

    Zhan, Ming-Xiu; Fu, Jianying; Chen, Tong; Li, Yeqing; Zhang, Jiang; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-10-01

    A bypass at the kiln inlet allows the effective reduction of alkali chloride cycles and thus perhaps affects the emission of PCDD/Fs. Effects of bypass system on PCDD/F emission and chlorine circulation were studied in two typical dry cement kilns with 5000 ton/day clinker capacity in China and named CK1 and CK2, respectively. Firstly, the emission level of PCDD/Fs with the operation of bypass system was estimated in CK1, to certify that bypass system has a perfect adaption to the cement kiln regarding the PCDD/F emission even with the refuse derived fuel (RDF) as the replacement of fuel. On the other hand, the operating conditions in the CK2 were scrutinised by monitoring the concentrations of SO2, NH3 and HCl. In addition, the characteristics of raw meal, clinker, bag filter ash and bypass ash were also investigated by Energy Dispersive Spectrometer (EDS), metal and chlorine analysis. The balance of chlorine showed that 18 % of the possible accumulated chlorine could be ejected from the cement kiln system when 2 % of kiln exhaust gas was extracted. Furthermore, the emission level of PCDD/Fs in the main flue gas also decreased from 0.037 ± 0.035 ng I-TEQ/Nm(3) to 0.019 ± 0.007 ng I-TEQ/Nm(3) with a reduction efficiency of 48.2 %. Most importantly, PCDD/F emission from the bypass system was proven to have rather minor effect on the total emission factor. The congener distributions of PCDD/Fs were also analysed in the flue gas and fly ash, before and after application of bypass system, to find cues to the formation mechanism.

  20. Quantitative analysis of anthropogenic relief features: automated mapping of charcoal kiln sites from high-resolution ALS data

    NASA Astrophysics Data System (ADS)

    Schneider, Anna; Takla, Melanie; Nicolay, Alexander; Raab, Alexandra; Raab, Thomas

    2014-05-01

    High-resolution digital elevation data from airborne laser scanning (ALS) allow for identification and mapping of so far unknown small-scale relief features that are hidden by forest cover. Especially as a result of historic land use, small anthropogenic landforms can occur, e.g., remains of charcoal kilns on sites that were used for charcoal production or ridge and furrow systems in former farmland areas. Mapping such relief features and analyzing their spatial distribution patterns can help to understand past land-use systems and their effects on landscapes. To efficiently detect and quantify small-scale relief features from high-resolution DEMs for larger areas, (semi-) automated mapping routines are required. In order to describe the number and spatial distribution of historic charcoal kiln sites in the area around Cottbus, Germany, we developed a GIS-based routine for the detection and mapping of kiln remnants from ALS elevation models with a resolution of 1 or 2 meters. The method is based on a template matching algorithm, using a combination of morphometric parameters, and is implemented within ArcGIS. The mapping results could be validated against a comprehensive database of kiln sites and diameters recorded from archaeological excavations in the forefield of the opencast mine Jänschwalde and from manual digitization of kiln remnants from Shaded Relief maps for the Jänschwalder Heide and the Tauersche Forst, north of Cottbus. A considerably high number of charcoal kiln sites could be detected in ALS data, and the diameters of the identified charcoal kilns are remarkable large in the area. For the Jänschwalder Heide, more than 5000 kiln sites in an area of 32 km2 were detected by manual digitization, with 1355 kiln sites that are wider than 12 m. These relatively large kiln sites could be mapped with detection rates that are close to those of manual digitization using the automated mapping routine. Detection quality was improved by the combination of

  1. PAH exposure biomarkers are associated with clinico-chemical changes in the brick kiln workers in Pakistan.

    PubMed

    Kamal, Atif; Malik, Riffat Naseem; Martellini, Tania; Cincinelli, Alessandra

    2014-08-15

    In this study we investigated the clinico-chemical parameters and the level of exposure of brick kiln workers to polycyclic aromatic hydrocarbons (PAHs) in Punjab (Pakistan). The brick kiln workers and a non-occupationally exposed group were recruited for comparative analysis of urinary biomarkers of PAH exposure (i.e. 1-hydroxypyrene (1-OHPyr), α-naphthol and β-naphthol) and blood level of superoxide dismutase (SOD), as a biomarker of oxidative stress and other hematologic parameters. Questionnaires were used to document information on socio-demographic characteristics of all the subjects. The analysis of urinary biomarkers showed higher median concentrations of 1-OHPyr, and α- and β-naphthols in brick kiln workers (1.53, 3.65 and 1.53 μmol/mol-Cr, respectively) than non-occupationally exposed group (0.62, 0.64 and 0.66 μmol/mol-Cr, respectively). The 1-OHPyr in brick kiln workers was above the occupational exposure level. Among the clinical parameters of brick kiln workers, hemoglobin (Hb) and red blood cells (RBCs) were very low and closely associate with 1-OHPyr and β-naphthol. Additionally, the white blood cells (WBCs) and superoxide dismutase (SOD) were also elevated in brick kiln workers, which suggested inflammatory symptoms and high oxidative stress. The results show that regardless of possibly being affected by the poor nutrition, the anemic state and hematological changes observed in brick kiln workers may be associated with their exposure to smoke present in the environment of brick kilns.

  2. Trace-metal fate in a rotary-kiln incinerator with an ionizing wet scrubber (journal article)

    SciTech Connect

    Waterland, L.R.; Fournier, D.J.; Lee, J.W.; Carroll, G.J.

    1991-01-01

    A series of pilot-scale incineration tests was performed at EPA's Incineration Research Facility (IRF) in Jefferson, Arkansas, to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with an ionizing wet scrubber (IWS) for particulate and acid gas control. Test variables were kiln temperature, ranging from 816 to 927 C (1500 to 1700 F); afterburner temperature, ranging from 982 to 1204 C (1800 to 2200 F); and feed chlorine content, ranging from 0 to 8 percent. The test program evaluated the fate of five hazardous constituent trace metals (arsenic, barium, cadmium, chromium, and lead) and four nonhazardous constituent trace metals (bismuth, copper, magnesium, and strontium). The test results indicate that cadmium and bismuth were relatively volatile, with an average of less than 40 percent discharged with the kiln ash. Arsenic, barium, chromium, copper, lead, magnesium, and strontium were relatively nonvolatile, with an average of greater than 80 percent discharged with the kiln ash. Observed relative metal volatilities generally agreed with the volatilities predicted based on vapor pressure/temperature relationships, with the exception of arsenic which was much less volatile than predicted. The volatility of cadmium, bismuth, and lead increased as kiln temperature was increased; the discharge distributions of the remaining metals were not significantly affected by changes in kiln temperature. Apparent scrubber collection efficiencies for the metals averaged 22 to 71 percent, and were generally higher for the less volatile metals. The overall average metal collection efficiency was 43 percent.

  3. Occupational Employment

    ERIC Educational Resources Information Center

    Occupational Outlook Quarterly, 2012

    2012-01-01

    When choosing a career, jobseekers often want to know which occupations offer the best prospects. Generally, occupations that have rapid job growth, many new jobs, or many job openings--and good wages--promise better opportunities. This paper shows how employment in particular occupations is projected to change from 2010 to 2020. It presents…

  4. Lime kiln dust as a potential raw material in portland cement manufacturing

    USGS Publications Warehouse

    Miller, M. Michael; Callaghan, Robert M.

    2004-01-01

    In the United States, the manufacture of portland cement involves burning in a rotary kiln a finely ground proportional mix of raw materials. The raw material mix provides the required chemical combination of calcium, silicon, aluminum, iron, and small amounts of other ingredients. The majority of calcium is supplied in the form of calcium carbonate usually from limestone. Other sources including waste materials or byproducts from other industries can be used to supply calcium (or lime, CaO), provided they have sufficiently high CaO content, have low magnesia content (less than 5 percent), and are competitive with limestone in terms of cost and adequacy of supply. In the United States, the lime industry produces large amounts of lime kiln dust (LKD), which is collected by dust control systems. This LKD may be a supplemental source of calcium for cement plants, if the lime and cement plants are located near enough to each other to make the arrangement economical.

  5. The production of synthetic aggregate from a quarry waste using an innovative style rotary kiln.

    PubMed

    Wainwright, R J; Cresswell, D J F; van der Sloot, H A

    2002-06-01

    The large volumes of wastes generated by industrialised society has led to efforts to find practical uses for these wastes, whilst also offsetting the consumption of natural resources. This paper describes the use of an innovative rotary kiln to produce synthetic aggregates from a variety of waste streams. The main waste used was a quarry fines which was blended with either paper sludge, clay, or a dredged harbour sediment. The different combinations were extruded and fired in the kiln to produce a material suitable for natural aggregate replacement. Two of the synthetic aggregates produced were tested by incorporation in to concrete as coarse aggregate replacement. The concrete 28-day compressive strengths achieved were above 40 N mm(-2) and compared favourably with control concretes made with natural aggregates and a commercially available lightweight aggregate (Lytag). Leaching tests have also been carried out to assess the potential environmental impact of utilisation. Although not finalised, these tests have also given favourable results.

  6. Impact of ancient charcoal kilns on chemical properties of several forest soils after 2 centuries

    NASA Astrophysics Data System (ADS)

    Dufey, Joseph; Hardy, Brieuc; Cornelis, Jean-Thomas

    2014-05-01

    Pyrogenic carbon plays a major role in soil biogeochemical processes and carbon budgets. Until the early 19th century, charcoal was the unique combustible used for iron metallurgy in Wallonia (Belgium). Traditional charcoal kilns were built directly in the forest: wood logs were piled into a mound and isolated from air oxygen with a covering of vegetation residues and soil before setting fire, inducing wood pyrolysis. Nowadays, ancient wood-charring platforms are still easy to identify on the forest floor as heightened domes of 10 meters in diameter characterized by a very dark topsoil horizon containing charcoal dust and fragments. Our goal is to assess the effects of wood charring at mound kiln sites on the properties of various forest soil types in Wallonia (Belgium), after two centuries. We sampled soil by horizon in 18 ancient kiln sites to 1.20 meter depth. The adjacent charcoal-unaffected soils were sampled the same way. We also collected recent charcoal fragments and topsoil samples from a still active charcoal kiln located close to Dole (France) to apprehend the evolution of soil properties over time. The pH, total carbon (C) and nitrogen (N) content, available phosphorus (Pav), cation exchange capacity at pH 7 (CEC), exchangeable cations (Ca++, Mg++, K+, Na+) and loss on ignition at 550°C (LI550) were measured on each soil sample. We separated the soil profiles in 5 groups based on the nature of soil substrate and pedogenesis for interpretation of the results. We show that the total carbon stock is significantly increased at kiln sites due to higher C concentrations and greater depth of the organo-mineral horizon. The C/N ratio in charcoal-enriched soil horizons is significantly higher than in the neighboring reference soils but clearly attenuated compared to pure wood-charcoal fragments. The CEC is higher in the charcoal-enriched soil horizons, not only due to higher C concentrations but also to increased CEC by carbon unit at kiln sites. The high

  7. Selenium recovery from kiln powder of cement manufacturing by chemical leaching and bioreduction.

    PubMed

    Soda, S; Hasegawa, A; Kuroda, M; Hanada, A; Yamashita, M; Ike, M

    2015-01-01

    A novel process by using chemical leaching followed by bacterial reductive precipitation was proposed for selenium recovery from kiln powder as a byproduct of cement manufacturing. The kiln powder at a slurry concentration of 10 w/v% with 0.25 M Na2CO3 at 28°C produced wastewater containing about 30 mg-Se/L selenium. The wastewater was diluted four-fold and adjusted to pH 8.0 as preconditioning for bioreduction. A bacterial strain Pseudomonas stutzeri NT-I, capable of reducing selenate and selenite into insoluble elemental selenium, could recover about 90% selenium from the preconditioned wastewater containing selenium of 5 mg-Se/L when supplemented with lactate or glycerol. The selenium concentrations in the treated wastewater were low around the regulated effluent concentration of 0.1 mg-Se/L in Japan.

  8. Destruction of DDT wastes in two preheater/precalciner cement kilns in China.

    PubMed

    Yan, Dahai; Peng, Zheng; Karstensen, Kåre Helge; Ding, Qiong; Wang, Kaixiang; Wang, Zuguang

    2014-04-01

    The destruction of DDT formulations and DDT contaminated soil was conducted by feeding wastes into the flue gas chamber at the kiln inlet of two different preheater/precalciner cement kilns in China. The concentration of DDT, PCDD/PCDFs and HCB were measured in the flue gas of the main stack, in the solid material under baseline conditions and when feeding DDT-wastes. The destruction efficiency and the destruction and removal efficiency for DDT were in the range of 99.9335%-99.9998% and 99.9984%-99.9999%, respectively. The emissions of PCDD/PCDFs and HCB in the flue gas varied in the range of 0.0019-0.0171 ng I-TEQ/Nm(3) and 0.0064-0.0404 μg/Nm(3), respectively. The emission factor for PCDD/PCDF and HCB varied from 0.0137 to 0.0281 μg/ton and from 17.32 to 109.34 μg/ton of clinker, respectively. The concentration of PCDD/PCDFs and HCB in solid samples decreased as follows: cement kiln dust, 4.1-5 ng I-TEQ/kg and 0.70-0.71 μg/kg, respectively; >raw meal, 0.82-0.97 ng I-TEQ/kg and 0.18 μg/kg, respectively; >cement clinker, 0.09-0.22 ng I-TEQ/kg and 0.14-0.18 μg/kg, respectively. This study indicates that the feeding of DDT and POPs-wastes to the lower temperature part of a cement kiln system possibly to create a buildup of trace not-destroyed compounds in the system and might cause emissions; the technical feasibility and the environmental acceptability of this practice need to be investigated thoroughly.

  9. Air pollution tolerance index of plants around brick kilns in Rawalpindi, Pakistan.

    PubMed

    Achakzai, Khanoranga; Khalid, Sofia; Adrees, Muhammad; Bibi, Aasma; Ali, Shafaqat; Nawaz, Rab; Rizwan, Muhammad

    2017-04-01

    In any contaminated environment, the sensitive plant species can serve as bio-indicator of air pollution while tolerant plant species can act as a sink for air pollutants. Air pollution tolerance index (APTI) is an important tool to screen out plants based on their tolerance or sensitivity level to different air pollutants. The present study was aimed to identify the sensitive and tolerant plant species in the vicinity of brick kilns in the Rawalpindi city. To determine the susceptibility level of the selected plant species, four biochemical parameters, ascorbic acid, total chlorophyll content, relative water content and pH of leaf extract, were assessed and APTI was calculated. Plant sampling was carried out with increasing distance of 100, 300 and 500 m around three brick kiln sites and APTI values were calculated by following the standard methods. The results of the study revealed that among nine studied plant species, Calotropis procera (APTI = 20.05) and Althernanthera pungens (APTI = 17.13) were found to be the most tolerant species, whereas Malva neglecta (APTI = 8.83) was found to be the most sensitive species. Inconsistent trend of variations was seen in the APTI values at each site. The present study suggested that the most tolerant species, C. procera and A. pungens, could be grown in the vicinity of such pollution sources as a remedial measure of brick kiln pollution.

  10. Leaching from waste incineration bottom ashes treated in a rotary kiln.

    PubMed

    Hyks, Jiri; Nesterov, Igor; Mogensen, Erhardt; Jensen, Peter A; Astrup, Thomas

    2011-10-01

    Leaching from municipal solid waste incineration bottom ash treated in a rotary kiln was quantified using a combination of lab-scale leaching experiments and geochemical modelling. Thermal treatment in the rotary kiln had no significant effect on the leaching of Al, Ba, Ca, Mg, Si, Sr, Zn, sulfate and inorganic carbon. Leaching of these elements from the treated residues remained unchanged and was, in general, controlled by solubility of the same minerals as in the untreated residues. Leaching of Cd, Co, Ni, Ti, Be, Bi, and Sn from both untreated and treated residues was found to be close to or below their detection limits; no effects of the thermal treatment on leachability of these metals were observed. The leaching of Cl, dissolved organic carbon (DOC), Cu and Pb decreased by at least one order of magnitude after the thermal treatment. This could be explained by evaporation (Cl) and by a better burnout of organic matter which then limited metal-DOC complexation and mobility. At the same time, leaching of Mo and Cr appeared to increase by a factor of 4 and more than two orders of magnitude, respectively. The large changes in Cr leaching may be explained by decreases in Al reduction capacity after the thermal treatment. Overall, rotary kiln thermal treatment of bottom ashes can be recommended to reduce the leaching of Cu, Pb, Cl and DOC; however, increased leaching of Cr and Mo should be expected.

  11. Organic and inorganic pollutants from cement kiln stack feeding alternative fuels.

    PubMed

    Conesa, Juan A; Gálvez, Araceli; Mateos, Fernán; Martín-Gullón, Ignacio; Font, Rafael

    2008-10-30

    In this work, an analysis of the emission of different pollutants when replacing partially the fuel type used in a cement kiln is done. The wastes used to feed the kiln were tyres and two types of sewage sludge. The increasing mass flow of sludge is between 700 kg h(-1) and 5,500 kg h(-1)1, for a total production of clinker of 150th(-1), whereas the fed tyres were in the flow range of 500-1,500 kg h(-1). Dioxins and furans, polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons, heavy metals, HCl and HF, CO, CO(2), NO(x) and other parameters of the stack were analyzed, according to the standard methods of sampling and determination, through more than 1 year in six series: one blank (no sewage sludge) and five more with increasing amount of sludge and/or tyres. The emission of PAHs and dioxins seems to increase with the amount of tyres fed to the kiln, probably due to the fed point used for this waste.

  12. Treatability testing of KILnGAS and Texaco coal gasification wastewaters: Final report

    SciTech Connect

    Peterson, D.L.; Eis, B.J.; Zeien, C.T.; Moe, T.A.; Turner, C.D.; Mayer, G.G.; Stephan, D.J.

    1988-07-01

    This report presents the results of treatability testing of wastewater from two coal gasification plants: the 600-tpd KILnGAS rotary-kiln gasifier in East Alton, Illinois, and the 1000-tyd Texaco entrained-flow gasifier at the Cool Water facility in Daggett, California. The wastewater was collected during steady-state operation of the gasifiers and shipped in barrels to the testing laboratory for characterization and treatment. Solvent extraction, steam stripping, biological treatment, granular activated carbon adsorption, ozonation, ion exchange, chemical precipitation, cooling tower evaporation, and wet air oxidation were evaluated in terms of their ability to meet the project's effluent quality targets. Preliminary process design criteria were also developed. Two sets of effluent discharge targets as well as a zero effluent discharge condition were established as goals for the testing. All of the effluent targets were met by the combination of processes used in the treatability testing program, with the exception of cyanide and COD for the KILnGAS wastewater and cyanide under one of the discharge conditions for the Texaco wastewater. These targets could likely be met by additional process steps or by further treatment with the processes tested. This test program confirmed that the principal containmants in these coal gasification wastewaters can be reduced to low concentrations by use of commercially proven treatment processes. 15 refs., 50 figs., 93 tabs.

  13. Thermal co-treatment of combustible hazardous waste and waste incineration fly ash in a rotary kiln.

    PubMed

    Huber, Florian; Blasenbauer, Dominik; Mallow, Ole; Lederer, Jakob; Winter, Franz; Fellner, Johann

    2016-12-01

    As current disposal practices for municipal solid waste incineration (MSWI) fly ash are either associated with significant costs or negative environmental impacts, an alternative treatment was investigated in a field scale experiment. Thereto, two rotary kilns were fed with hazardous waste, and moistened MSWI fly ash (water content of 23%) was added to the fuel of one kiln with a ratio of 169kg/Mg hazardous waste for 54h and 300kg/Mg hazardous waste for 48h while the other kiln was used as a reference. It was shown that the vast majority (>90%) of the inserted MSWI fly ash was transferred to the bottom ash of the rotary kiln. This bottom ash complied with the legal limits for non-hazardous waste landfills, thereby demonstrating the potential of the investigated method to transfer hazardous waste (MSWI fly ash) into non-hazardous waste (bottom ash). The results of a simple mixing test (MSWI fly ash and rotary kiln bottom ash have been mixed accordingly without thermal treatment) revealed that the observed transformation of hazardous MSWI fly ash into non-hazardous bottom ash during thermal co-treatment cannot be referred to dilution, as the mixture did not comply with legal limits for non-hazardous waste landfills. For the newly generated fly ash of the kiln, an increase in the concentration of Cd, K and Pb by 54%, 57% and 22%, respectively, was observed. In general, the operation of the rotary kiln was not impaired by the MSWI fly ash addition.

  14. Concentrations and patterns of polychlorinated biphenyls at different process stages of cement kilns co-processing waste incinerator fly ash.

    PubMed

    Liu, Guorui; Yang, Lili; Zhan, Jiayu; Zheng, Minghui; Li, Li; Jin, Rong; Zhao, Yuyang; Wang, Mei

    2016-12-01

    Cement kilns can be used to co-process fly ash from municipal solid waste incinerators. However, this might increase emission of organic pollutants like polychlorinated biphenyls (PCBs). Knowledge of PCB concentrations and homolog and congener patterns at different stages in this process could be used to assess the possibility of simultaneously controlling emissions of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) and "dioxin-like" compounds. To date, emissions from cement kilns co-processing fly ash from municipal solid waste incinerators have not been analyzed for PCBs. In this study, stack gas and particulate samples from two cement kilns co-processing waste incinerator fly ash were analyzed for PCBs. The average total tri- to deca-chlorinated biphenyl (∑3-10PCB) concentration in the stack gas samples was 10.15ngm(-3). The ∑3-10PCB concentration ranges in particulate samples from different stages were 0.83-41.79ngg(-1) for cement kiln 1and0.13-1.69ngg(-1) for cement kiln 2. The ∑3-10PCB concentrations were much higher in particulate samples from the suspension pre-heater boiler, humidifier tower, and kiln back-end bag filters than in particulate samples from other stages. For these three stages, PCBs contributed to 15-18% of the total PCB, PCDD/F, and polychlorinated naphthalene toxic equivalents in stack gases and particulate matter. The PCB distributions were similar to those found in other studies for PCDD/Fs and polychlorinated naphthalenes, which suggest that it may be possible to simultaneously control emissions of multiple organic pollutants from cement kilns. Homolog patterns in the particulate samples were dominated by the pentachlorobiphenyls. CB-105, CB-118, and CB-123 were the dominant dioxin-like PCB congeners that formed at the back-end of the cement kiln. A mass balance of PCBs in the cement kilns indicated that the total mass of PCBs in the stack gases and clinker was about half the mass of PCBs in the raw materials.

  15. Model and simulation of heat transfer, magnetite oxidation and NOx formation in a grate-kiln taconite pellet induration furnace

    SciTech Connect

    Davis, R.A.

    1996-12-31

    A numerical model was developed to simulate the combined effects of heat transfer, magnetite oxidation, and NO{sub x} formation in a grate-kiln furnace for taconite pellet induration. Heat transfer from the flame in the kiln was described by the net radiation method. The shrinking core model was used to account for magnetite oxidation on the grate. A novel approach to oxidation of tumbling pellets in a kiln was derived. The Zeldovich mechanism was used to predict thermal NO generation. Temperature fluctuations in the gas streams were estimated with a clipped Gaussian probability density function. The thermal energy balances and mass balances resulted in coupled systems of first-order differential equations, which were solved numerically. The model is capable of predicting NO production and magnetite oxidation in agreement with observation of plant performance. Although the design of the grate-kiln system is for efficient heat and mass transfer, it may not be the optimal design for minimizing the formation of NOx. When natural gas is used to fuel the kiln burner in the presence of excess air, the principal mechanism of NOx formation is the thermally induced combination of oxygen and nitrogen in the air in the post combustion zone after the burner.

  16. 40 CFR Table 8 to Subpart Dddd of... - Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Model Rule-Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 8 Table 8 to Subpart DDDD of Part 60 Protection of...—Emission Limitations That Apply to Waste-Burning Kilns After May 20, 2011 For the air pollutant You...

  17. [Line scanning analysis of white porcelain from Gong Kiln in early Tang dynasty by energy disperse X-ray fluorescence].

    PubMed

    Ling, Xue; Mao, Zhen-wei; Feng, Min; Hu, Yao-wu; Wang, Chang-sui; Liu, Hong-miao

    2005-07-01

    Gong kiln, for its long porcelain-firing history, was one of three representative white porcelain kilns in northern China. In order to improve the quality and whiteness of white porcelain, a decorating layer or cosmetic earth was laid on the body surface in Gong kiln during early Tang dynasty, which was able to blot out rough surface and weaken the influence of fuscous body upon surface color. In this paper the main chemical composition of the white porcelain's profile was analyzed by using energy disperse X-Ray fluorescence. The result showed that different materials were used as cosmetic earth during early Tang dynasty, in accordance with the phenomenon under optical microscope. In addition, the glaze belongs to calcium glaze in which plant ash was added.

  18. Increasing Energy Efficiency and Reducing Emissions from China's Cement Kilns. Audit Report of Two Cement Plants in Shandong Province, China

    SciTech Connect

    Price, Lynn; Hasanbeigi, Ali; Zhou, Nan; Thekdi, Arvind; Lan, Wang

    2011-07-01

    The study documented in this report was initiated in order to conduct an energy assessment and to identify the relationship between combustion issues and emissions from cement kilns. A new suspension preheater/precalciner (NSP) rotary cement kiln at one cement manufacturing facility (referred to as Shui Ni 1 in this report) and a vertical shaft kiln (VSK) at another cement manufacturing facility (referred to as Shui Ni 2 in this report), which are both in Shandong Province, were selected to conduct the energy and emission assessments through collection of data. Based on analysis of the data collected during this assessment, several actions are suggested that could lead to reduction in coal use and reduction in emission of gaseous pollutants from the system.

  19. Ultra high temperature gasification of municipal wastewater primary biosolids in a rotary kiln reactor for the production of synthesis gas.

    PubMed

    Gikas, Petros

    2016-03-03

    Primary Fine-Sieved Solids (PFSS) are produced from wastewater by the use of micro-sieves, in place of primary clarification. Biosolids is considered as a nuisance product, however, it contains significant amounts of energy, which can be utilized by biological (anaerobic digestion) or thermal (combustion or gasification) processes. In the present study, an semi-industrial scale UHT rotary kiln gasifier, operating with electric energy, was employed for the gasification of PFSS (at 17% moisture content), collected from a municipal wastewater treatment plant. Two gasification temperatures (950 and 1050 °C) had been tested, with minimal differences, with respect to syngas yield. The system appears to reach steady state after about 30-40 min from start up. The composition of the syngas at near steady state was measured approximately as 62.4% H2, 30.0% CO, 2.4% CH4 and 3.4% CO2, plus 1.8% unidentified gases. The potential for electric energy production from the syngas produced is theoretically greater than the electric energy required for gasification. Theoretically, approximately 3.8 MJ/kg PFSS of net electric energy may be produced. However, based on the measured electric energy consumption, and assuming that all the syngas produced is used for electric energy production, addition of excess electric energy (about 0.43 MJ/kg PFSS) is required to break even. The latter is probably due to heat losses to the environment, during the heating process. With the improvement of energy efficiency, the process can be self sustained, form the energy point of view.

  20. Evaluation of the release of dioxins and PCBs during kiln-firing of ball clay.

    PubMed

    Broadwater, Kendra; Meeker, John D; Luksemburg, William; Maier, Martha; Garabrant, David; Demond, Avery; Franzblau, Alfred

    2014-01-01

    Ball clay is known to be naturally contaminated with high levels of polychlorinated di-benzo-p-dioxins (PCDDs). This study evaluated the potential for PCDD, polychlorinated dibenzofuran (PCDF) and polychlorinated biphenyl (PCB) release during the kiln firing of ball clay in an art studio. Toxic equivalence (TEQ) were calculated using World Health Organization (WHO) 2005 toxic equivalence factors (TEF) and congener concentrations. Ten bags of commercial ball clay were found to have an average TEQ of 1,370 nanograms/kilogram (ng kg(-1)) dry weight (dw), almost exclusively due to PCDDs (99.98% of TEQ). After firing, none of the 29 dioxin-like analytes was measured above the limits of detection (LOD) in the clay samples. Air samples were taken during firings using both low-flow and high-flow air samplers. Few low-flow air samples contained measurable levels of dioxin congeners above the LOD. The mean TEQ in the high volume air samples ranged from 0.07 pg m(-3) to 0.21 pg m(-3) when firing ball clay, and was 0.11 pg m(-3) when no clay was fired. These concentrations are within the range measured in typical residences and well-controlled industrial settings. The congener profiles in the high-flow air samples differed from the unfired clay; the air samples had a considerable contribution to the TEQ from PCDFs and PCBs. Given that the TEQs of all air samples were very low and the profiles differed from the unfired clay, it is likely that the PCDDs in dry ball clay were destroyed during kiln firing. These results suggest that inhalation of volatilized dioxins during kiln firing of dry ball clay is an unlikely source of exposure for vocational and art ceramicists.

  1. Validity of archaeomagnetic field recording: an experimental pottery kiln at Coppengrave, Germany.

    PubMed

    Schnepp, Elisabeth; Leonhardt, Roman; Korte, Monika; Klett-Drechsel, Johannes

    2016-04-01

    Palaeomagnetic data obtained from archaeological materials are used for reconstructions of the Earth's magnetic field of the past millennia. While many studies tested the reliability of this recorder for palaeointensity only a few studies did this for direction. The study presents an archaeomagnetic and rock magnetic investigation applied to an experimental pottery kiln, which was operated in 2003 to produce stone ware. This kind of high-quality pottery needs a temperature of at least 1160 °C. Shortly before heating of the kiln direct absolute measurements of the absolute geomagnetic field vector have been carried out close to it. After cooling of the kiln 24 oriented palaeomagnetic samples have been taken. Although Curie temperatures are about 580 °C, that is the typical temperature for magnetite, thermal as well as alternating field demagnetisations reveal also a considerable amount of hematite as magnetic carrier. This mixture of magnetite and hematite is dominated by pseudo-single domain grains. Demagnetisation removed in some cases weak secondary components, but in most cases the specimens carried a single component thermoremanent magnetisation. The mean characteristic remanent magnetisation direction agrees on 95 per cent confidence level with the directly measured field direction. Archaeointensity was obtained from five specimens with the Thellier-Coe method and with the multiple-specimen palaeointensity domain-state corrected method. Six of these specimens also provided a result of the Dekkers-Böhnel method, which overestimated the archaeointensity by about 9 per cent compared to the direct value, while after correction for fraction the value agrees very well. For the multiple-specimen palaeointensity domain-state corrected method only fractions between 25 and 75 per cent have been used and specimens showing alteration have been excluded. Above 450 °C many specimens showed alteration of the magnetic grains. Because median destructive

  2. Airborne Particulate Matter and Health Condition in Brick Kiln Workers in Kathmandu Valley, Nepal.

    PubMed

    Sanjel, S; Khanal, S N; Thygerson, S M; Khanal, K; Pun, Z; Tamang, S; Joshi, S K

    2016-01-01

    Background Air quality monitoring in brick kilns indicates very high concentrations of airborne particulate matter. Air pollution from brick kilns poses an enhanced threat to the environment and to human health. Objective To evaluate airborne particulate matter concentration and health status of brick kiln workers. Method A cross-sectional comparative study was conducted in the Kathmandu valley targeting all brick industries and their workers during January - March 2015 and March - April 2016. A total of 16 brick kilns and 800 participants (400 brick workers as exposed and 400 grocery workers as referent) were selected for study. A direct-reading, Dusttrak model 8533 was used for air sampling. Nepali version questionnaire was applied to obtain epidemiological data. SPSS version 16 was used to perform statistical analysis. Median, mean, range and proportion were calculated and Mann-Whitney U test, Kruskal-Wallis test and chi square (c2) test were applied to test significance. Result Mean values of particulate matter concentrations for brickfields were as follows: Total Suspended Particulate Matter (TSPM): 5.179 mg/m3, PM10: 4.958 mg/m3, respirable suspended particulate matter (RSPM): 4.140 mg/m3, PM2.5: 3.965 mg/m3, and PM1: 3.954 mg/m3. The mean concentrations for grocery workers were; TSPM: 0.089 mg/ m3, PM10: 0.089 mg/m3, RSPM: 0.085 mg/m3, PM2.5: 0.082 mg/m3 and PM1: 0.082 mg/m3. Among brickfield workers, red and green brick loading zones had results that exceeded the ACGIH Threshold Limit Values for TSPM and RSPM. Workers complaints of injury were 52% and 44.2%, and illnesses were 88.5% and 82.2%, respectively among exposed and referent. The occurrence of injuries/illnesses during work showed significant association between exposed and the referent groups at 0.05 level. Conclusion The high level of airborne particulate matter in the brick fields requires action for the protection of workers. The availability of health services within brick industries needs to

  3. Validity of archaeomagnetic field recording: an experimental pottery kiln at Coppengrave, Germany

    NASA Astrophysics Data System (ADS)

    Schnepp, Elisabeth; Leonhardt, Roman; Korte, Monika; Klett-Drechsel, Johannes

    2016-04-01

    Palaeomagnetic data obtained from archaeological materials are used for reconstructions of the Earth's magnetic field of the past millennia. While many studies tested the reliability of this recorder for palaeointensity only a few studies did this for direction. The study presents an archaeomagnetic and rock magnetic investigation applied to an experimental pottery kiln, which was operated in 2003 to produce stone ware. This kind of high-quality pottery needs a temperature of at least 1160 °C. Shortly before heating of the kiln direct absolute measurements of the absolute geomagnetic field vector have been carried out close to it. After cooling of the kiln 24 oriented palaeomagnetic samples have been taken. Although Curie temperatures are about 580 °C, that is the typical temperature for magnetite, thermal as well as alternating field demagnetisations reveal also a considerable amount of hematite as magnetic carrier. This mixture of magnetite and hematite is dominated by pseudo-single domain grains. Demagnetisation removed in some cases weak secondary components, but in most cases the specimens carried a single component thermoremanent magnetisation. The mean characteristic remanent magnetisation direction agrees on 95 per cent confidence level with the directly measured field direction. Archaeointensity was obtained from five specimens with the Thellier-Coe method and with the multiple-specimen palaeointensity domain-state corrected method. Six of these specimens also provided a result of the Dekkers-Böhnel method, which overestimated the archaeointensity by about 9 per cent compared to the direct value, while after correction for fraction the value agrees very well. For the multiple-specimen palaeointensity domain-state corrected method only fractions between 25 and 75 per cent have been used and specimens showing alteration have been excluded. Above 450 °C many specimens showed alteration of the magnetic grains. Because median destructive temperatures were

  4. Emissions and Char Quality of Flame-Curtain "Kon Tiki" Kilns for Farmer-Scale Charcoal/Biochar Production

    PubMed Central

    Cornelissen, Gerard; Pandit, Naba Raj; Taylor, Paul; Pandit, Bishnu Hari; Sparrevik, Magnus; Schmidt, Hans Peter

    2016-01-01

    Flame Curtain Biochar Kilns Pyrolysis of organic waste or woody materials yields charcoal, a stable carbonaceous product that can be used for cooking or mixed into soil, in the latter case often termed "biochar". Traditional kiln technologies for charcoal production are slow and without treatment of the pyrolysis gases, resulting in emissions of gases (mainly methane and carbon monoxide) and aerosols that are both toxic and contribute to greenhouse gas emissions. In retort kilns pyrolysis gases are led back to a combustion chamber. This can reduce emissions substantially, but is costly and consumes a considerable amount of valuable ignition material such as wood during start-up. To overcome these problems, a novel type of technology, the Kon-Tiki flame curtain pyrolysis, is proposed. This technology combines the simplicity of the traditional kiln with the combustion of pyrolysis gases in the flame curtain (similar to retort kilns), also avoiding use of external fuel for start-up. Biochar Characteristics A field study in Nepal using various feedstocks showed char yields of 22 ± 5% on a dry weight basis and 40 ± 11% on a C basis. Biochars with high C contents (76 ± 9%; n = 57), average surface areas (11 to 215 m2 g-1), low EPA16—PAHs (2.3 to 6.6 mg kg-1) and high CECs (43 to 217 cmolc/kg)(average for all feedstocks, mainly woody shrubs) were obtained, in compliance with the European Biochar Certificate (EBC). Gas Emission Factors Mean emission factors for the flame curtain kilns were (g kg-1 biochar for all feedstocks); CO2 = 4300 ± 1700, CO = 54 ± 35, non-methane volatile organic compounds (NMVOC) = 6 ± 3, CH4 = 30 ± 60, aerosols (PM10) = 11 ± 15, total products of incomplete combustion (PIC) = 100 ± 83 and NOx = 0.4 ± 0.3. The flame curtain kilns emitted statistically significantly (p<0.05) lower amounts of CO, PIC and NOx than retort and traditional kilns, and higher amounts of CO2. Implications With benefits such as high quality biochar, low emission

  5. Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1

    PubMed Central

    Kunal; Rajor, Anita; Siddique, Rafat

    2016-01-01

    This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 6–12, temperatures of 28–50 °C, and NaCl concentrations of 0–16% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications. PMID:26887220

  6. Feasibility of disposing waste glyphosate neutralization liquor with cement rotary kiln.

    PubMed

    Bai, Y; Bao, Y B; Cai, X L; Chen, C H; Ye, X C

    2014-08-15

    The waste neutralization liquor generated during the glyphosate production using glycine-dimethylphosphit process is a severe pollution problem due to its high salinity and organic components. The cement rotary kiln was proposed as a zero discharge strategy of disposal. In this work, the waste liquor was calcinated and the mineralogical phases of residue were characterized by scanning electron microscope (SEM) and X-ray diffraction (XRD). The mineralogical phases and the strength of cement clinker were characterized to evaluate the influence to the products. The burnability of cement raw meal added with waste liquor and the calorific value of waste liquor were tested to evaluate the influence to the thermal state of the kiln system. The results showed that after the addition of this liquor, the differences of the main phases and the strength of cement clinker were negligible, the burnability of raw meal was improved; and the calorific value of this liquor was 6140 J/g, which made it could be considered as an alternative fuel during the actual production.

  7. Bacterial treatment of alkaline cement kiln dust using Bacillus halodurans strain KG1.

    PubMed

    Kunal; Rajor, Anita; Siddique, Rafat

    2016-01-01

    This study was conducted to isolate an acid-producing, alkaliphilic bacterium to reduce the alkalinity of cement industry waste (cement kiln dust). Gram-positive isolate KG1 grew well at pH values of 6-12, temperatures of 28-50°C, and NaCl concentrations of 0-16% and thus was further screened for its potential to reduce the pH of an alkaline medium. Phenotypic characteristics of the KG1 isolate were consistent with those of the genus Bacillus, and the highest level of 16S rRNA gene sequence similarity was found with Bacillus halodurans strain DSM 497 (94.7%). On the basis of its phenotypic characteristics and genotypic distinctiveness from other phylogenetic neighbors belonging to alkaliphilic Bacillus species, the isolated strain was designated B. halodurans strain KG1, with GenBank accession number JQ307184 (= NCIM 5439). Isolate KG1 reduced the alkalinity (by 83.64%) and the chloride content (by 86.96%) of cement kiln dust and showed a potential to be used in the cement industry for a variety of applications.

  8. Coal pyrolysis in a rotary kiln: Part 2. Overall model of the furnace

    SciTech Connect

    Patisson, F.; Lebas, E.; Hanrot, F.; Ablitzer, D.; Houzelot, J.L.

    2000-04-01

    In order to simulate coal pyrolysis in a rotary kiln in the steady-state regime, a mathematical model has been developed which calculates the temperature profiles in the charge, the gas, and the furnace walls, together with the gas composition and the degree of removal of volatile species. The model takes into account the principal physiochemical and thermal phenomena involved, including the complex movements of the charge; the gas flow; heat transfer between the charge, the gas phase, and the furnace walls; drying and pyrolysis of the coal; the cracking of tars; the combustion of volatile species; and the combustion and extinction of the coke. The data necessary for the model were obtained by specific experiments or from the literature. The model has been validated by comparing its predictions to measurements performed to an industrial rotary kiln. The model has been used to study the influence of operating parameters such as the furnace rotation speed, in order to optimize the process. It is shown how a modification to the extinction zone leads to an increase in coke yield of 0.75 pct.

  9. Metal Ion Removal from Wastewaters by Sorption on Activated Carbon, Cement Kiln Dust, and Sawdust.

    PubMed

    Shaheen, Sabry M; Eissa, Fawzy I; Ghanem, Khaled M; El-Din, Hala M Gamal; Al Anany, Fathia S

    2015-06-01

    This study assessed the efficiency of activated carbon, cement kiln dust (CKD), and sawdust for the removal of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) from aqueous solutions under mono-metal and competitive sorption systems and the removal of Cd, Cu, and Zn from different industrial wastewaters. Batch equilibrium experiments were conducted in a mono-metal and competitive sorption system. The efficiency of the sorbents in the removal of Cd, Cu, and Zn from industrial wastewaters was also investigated. Cement kiln dust expressed the highest affinity for the metals followed by activated carbon and sawdust. Competition among the metals changed their distribution coefficient (Kd) with the sorbents. Sorption of Pb and Cu was higher than Cd and Zn. The average metal removal from the wastewaters varied from 74, 61, and 60% for Cd, Cu, and Zn, respectively, to nearly 100%. The efficiencies of CKD and activated carbon in removing metals were higher than sawdust, suggesting their potential as low-cost sorbents for the removal of toxic metals from wastewaters.

  10. Modeling the combustion behavior of hazardous waste in a rotary kiln incinerator.

    PubMed

    Yang, Yongxiang; Pijnenborg, Marc J A; Reuter, Markus A; Verwoerd, Joep

    2005-01-01

    Hazardous wastes have complex physical forms and chemical compositions and are normally incinerated in rotary kilns for safe disposal and energy recovery. In the rotary kiln, the multifeed stream and wide variation of thermal, physical, and chemical properties of the wastes cause the incineration system to be highly heterogeneous, with severe temperature fluctuations and unsteady combustion chemistry. Incomplete combustion is often the consequence, and the process is difficult to control. In this article, modeling of the waste combustion is described by using computational fluid dynamics (CFD). Through CFD simulation, gas flow and mixing, turbulent combustion, and heat transfer inside the incinerator were predicted and visualized. As the first step, the waste in various forms was modeled to a hydrocarbon-based virtual fuel mixture. The combustion of the simplified waste was then simulated with a seven-gas combustion model within a CFD framework. Comparison was made with previous global three-gas combustion model with which no chemical behavior can be derived. The distribution of temperature and chemical species has been investigated. The waste combustion model was validated with temperature measurements. Various operating conditions and the influence on the incineration performance were then simulated. Through this research, a better process understanding and potential optimization of the design were attained.

  11. Stack emissions tests in a brick manufacturing Hoffmann kiln: firing of municipal solid waste.

    PubMed

    Ubaque, C A García; Hässig, A Gonzales; Mendoza, C Acosta

    2010-07-01

    This article reviews the results obtained from stack emissions analysis during the co-firing process of municipal solid waste (MSW) from the municipality of Tabio, Colombia, in a Hoffmann-type brick kiln. MSW (2 tonne) was incinerated and about 18.5 tonnes of clay were processed into brick using one and four kiln chambers, respectively. During the process, the following emissions were investigated: particulate emissions, emissions of SO(2), SO(3), NO( X), metals (Sb, As, Cd, Co, Sn, Cr, Cu, Mn, Ni, Hg), hydrofluoric and hydrochloric acid, hydrocarbons (such as methane) and emission of polychlorinated dioxins and furans. Also, CO emissions were monitored during each test to evaluate the influence of MSW co-firing on that parameter. The observed emissions concentrations proved to be below the threshold values issued by MAVDT, the environmental authority in Colombia, indicating that the emissions were under control during the proposed process. In addition, statistical analysis showed that the emissions were 10-40% below the regulation limit with a confidence of 95%.

  12. [Release amount of heavy metals in cement product from co-processing waste in cement kiln].

    PubMed

    Yang, Yu-Fei; Huang, Qi-Fei; Zhang, Xia; Yang, Yu; Wang, Qi

    2009-05-15

    Clinker was produced by Simulating cement calcination test, and concrete samples were also prepared according to national standard GB/T 17671-1999. Long-term cumulative release amount of heavy metals in cement product from co-processing waste in cement kiln was researched through leaching test which refers to EA NEN 7371 and EA NEN 7375, and one-dimensional diffusion model which is on the base of Fick diffusion law. The results show that availabilities of heavy metals are lower than the total amounts in concrete. The diffusion coefficients of heavy metals are different (Cr > As > Ni > Cd). During 30 years service, the cumulative release amounts of Cr, As, Ni and Cd are 4.43 mg/kg, 0.46 mg/kg, 1.50 mg/kg and 0.02 mg/kg, respectively, and the ratios of release which is the division of cumulative release amount and availability are 27.0%, 18.0%, 3.0% and 0.2%, respectively. The most important influence factor of cumulative release amount of heavy metal is the diffusion coefficient, and it is correlative to cumulative release amount. The diffusion coefficient of Cr and As should be controlled exactly in the processing of input the cement-kiln.

  13. Influence of the composition of cement kiln dust on its interaction with fly ash and slag

    SciTech Connect

    Chaunsali, Piyush; Peethamparan, Sulapha

    2013-12-15

    Cement kiln dust (CKD), a by-product of the cement industry, contains significant amounts of alkali, free lime, chloride and sulfate. Wide variation reported in the chemical composition of CKDs limits their potential application as a sustainable binder component in concrete. In the current study, the performance of two different CKDs as components in a novel binder is evaluated. Several binders are developed by blending CKDs with fly ash or slag. Binders with 70% CKD were prepared at a water-to-binder ratio of 0.4, and heat-cured at 75 °C to accelerate the strength development. The hydration progress was monitored using X-ray diffraction, and morphological examination was performed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Ettringite and calcium aluminosilicate hydrate (C-A-S-H) were identified as the main hydration products in the hardened binder system. Strength development of CKD-based binder was found to be significantly influenced by its free lime and sulfate contents. -- Highlights: •Interaction of cement kiln dust with fly ash and slag was explored. •CKD with higher free lime and sulfate content increased the strength of binder. •C-S-H like reaction gel with fibrillar morphology is observed in CKD-based binders.

  14. Investigation into the use of cement kiln dust in high density sludge (HDS) treatment of acid mine water.

    PubMed

    Mackie, Allison L; Walsh, Margaret E

    2015-11-15

    The purpose of this study was to investigate the potential to replace lime with cement kiln dust (CKD) in high density sludge (HDS) treatment of acid mine drainage (AMD). The bench-scale study used two water samples: AMD sampled from a lead-zinc mine with high concentrations of iron (Fe), zinc (Zn), and arsenic (As) (Fe/Zn-AMD) and a synthetic AMD solution (Syn-AMD) spiked with ferric sulfate (Fe2(SO4)3). Arsenic was found to be significantly reduced with CKD-HDS treatment of Fe/Zn-AMD compared to lime-HDS treatment, to concentrations below the stringent mine effluent discharge regulation of 0.10 mg As/L (i.e., 0.04 ± 0.02 mg/L). Both CKD- and lime-HDS treatment of the two AMD samples resulted in settled water Fe concentrations above the stringent discharge guideline of 0.3 mg Fe/L. CKD addition in the HDS process also resulted in high settled water turbidity, above typical discharge guidelines of 15 mg TSS/L. CKD-HDS treatment was found to result in significantly improved settled solids (i.e., sludge) quality compared to that generated in the lime-HDS process. HDS treatment with CKD resulted in 25-88% lower sludge volume indices, 2 to 9 times higher % wet solids, and 10 to 20 times higher % dry solids compared to lime addition. XRD and XPS testing indicated that CKD-HDS sludge consisted of mainly CaCO3 and SiO2 with Fe(3+) precipitates attached at particle surfaces. XRD and XPS testing of the lime-HDS generated sludge showed that it consisted of non-crystalline Fe oxides typical of sludge formed from precipitates with a high water concentration. Increased sedimentation rates were also found for CKD (1.3 cm/s) compared to lime (0.3 cm/s). The increased solids loading with CKD addition compared to lime addition in the HDS process was suggested to both promote surface complexation of metal precipitates with insoluble CKD particles and increase compression effects during Type IV sedimentation. These mechanisms collectively contributed to the reduced water content of

  15. Coal desulfurization in a rotary kiln combustor. Quarterly report No. 1, April 16, 1990--July 15, 1990

    SciTech Connect

    Cobb, J.T. Jr.

    1990-08-15

    BCR National Laboratory (BCRNL) has initiated a project aimed at evaluating the technical and economic feasibility of using a rotary kiln, suitably modified, to burn Pennsylvania anthracite wastes, co-fired with high-sulfur bituminous coal. Limestone will be injected into the kiln for sulfur control, to determine whether high sulfur capture levels can be achieved with high sorbent utilization. The principal objectives of this work are: (1) to prove the feasibility of burning anthracite refuse, with co-firing of high-sulfur bituminous coal and with limestone injection for sulfur emissions control, in a rotary kiln fitted with a Universal Energy International (UEI) air injector system; (2) to determine the emissions levels of SO{sub x} and NO{sub x} and specifically to identify the Ca/S ratios that are required to meet New Source Performance Standards; (3) to evaluate the technical and economic merits of a commercial rotary kiln combustor in comparison to fluidized bed combustors; and, (4) to ascertain the need for further work, including additional combustion tests, prior to commercial application, and to recommend accordingly a detailed program towards this end.

  16. Effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions.

    PubMed

    Lv, Dong; Zhu, Tianle; Liu, Runwei; Lv, Qingzhi; Sun, Ye; Wang, Hongmei; Liu, Yu; Zhang, Fan

    2016-09-01

    The effects of co-processing sewage sludge in cement kiln on NOx, NH3 and PAHs emissions were systematically investigated in a cement production line in Beijing. The results show that co-processing the sewage sludge was helpful to reduce NOx emission, which primarily depends on the NH3 amount released from the sewage sludge. Meanwhile, NOx and NH3 concentrations in the flue gas have a negative correlation, and the contribution of feeding the sewage sludge to NOx removal decreased with the increase of injection amount of ammonia water in the SNCR system. Therefore, it is suggested that the injection amount of ammonia water in SNCR system may reduce to cut down the operating costs during co-processing the sewage sludge in cement kiln. In addition, the emission of total PAHs seems to increase with the increased amount of the sewage sludge feeding to the cement kiln. However, the distributions of PAHs were barely changed, and lower molecular weight PAHs were mainly distributed in gaseous phase, accounted for the major portion of PAHs when co-processing sewage sludge in cement kiln.

  17. 40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...; and (7) Particulate matter in excess of 57 mg/dscm corrected to 7 percent oxygen. (b) Emission limits... Combustors Interim Emissions Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight... that are effective until compliance with the standards under § 63.1221? (a) Emission limits...

  18. 40 CFR 63.1221 - What are the replacement standards for hazardous waste burning lightweight aggregate kilns?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., corrected to 7 percent oxygen. (b) Emission and hazardous waste feed limits for new sources. You must not... Pollutants from Hazardous Waste Combustors Replacement Emissions Standards and Operating Limits for... hazardous waste burning lightweight aggregate kilns? (a) Emission and hazardous waste feed limits...

  19. 40 CFR 63.1205 - What are the standards for hazardous waste burning lightweight aggregate kilns that are effective...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...; and (7) Particulate matter in excess of 57 mg/dscm corrected to 7 percent oxygen. (b) Emission limits... Combustors Interim Emissions Standards and Operating Limits for Incinerators, Cement Kilns, and Lightweight... that are effective until compliance with the standards under § 63.1221? (a) Emission limits...

  20. 40 CFR 63.1343 - What standards apply to my kilns, clinker coolers, raw material dryers, and open clinker piles?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., clinker cooler, and raw material dryer. All dioxin D/F, HCl, and total hydrocarbon (THC) emission limits are on a dry basis. The D/F, HCl and THC limits for kilns are corrected to 7 percent oxygen except during periods of startup and shutdown. The raw material dryer THC limits are corrected to 19...

  1. 40 CFR 63.1343 - What standards apply to my kilns, clinker coolers, raw material dryers, and open clinker piles?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., clinker cooler, and raw material dryer. All dioxin D/F, HCl, and total hydrocarbon (THC) emission limits are on a dry basis. The D/F, HCl and THC limits for kilns are corrected to 7 percent oxygen except during periods of startup and shutdown. The raw material dryer THC limits are corrected to 19...

  2. Gaseous pollutants from brick kiln industry decreased the growth, photosynthesis, and yield of wheat (Triticum aestivum L.).

    PubMed

    Adrees, Muhammad; Ibrahim, Muhammad; Shah, Aamir Mehmood; Abbas, Farhat; Saleem, Farhan; Rizwan, Muhammad; Hina, Saadia; Jabeen, Fariha; Ali, Shafaqat

    2016-05-01

    Gaseous pollutant emissions from brick kiln industries deteriorate the current state of ambient air quality in Pakistan and worldwide. These gaseous pollutants affect the health of plants and may decrease plant growth and yield. A field experiment that was conducted to monitor the concentration of gaseous pollutants emitted mainly from brick kilns in the ambient air and associated impacts on the growth and physiological attributes of the two wheat (Triticum spp.) cultivars. Plants were grown at three sites, including control (Ayub Agriculture Research Institute, AARI), low pollution (LP) site (Small Estate Industry), and high pollution (HP) site (Sidar Bypass), of Faisalabad, Pakistan. Monitoring of ambient air pollution at experimental sites was carried out using the state-of-art ambient air analyzers. Plants were harvested after 120 days of germination and were analyzed for different growth attributes. Results showed that the hourly average concentration of gaseous air pollutants CO, NO2, SO2, and PM10 at HP site were significantly higher than the LP and control sites. Similarly, gaseous pollutants decreased plant height, straw and grain yield, photosynthesis and increased physical injury, and metal concentrations in the grains. However, wheat response toward gaseous pollutants did not differ between cultivars (Galaxy and 8173) studied. Overall, the results indicated that brick kiln emissions could reduce the performance of wheat grown in the soils around kilns and confirm the adverse impacts of pollutants on the growth, yield, and quality of the wheat.

  3. Modeling of Process Parameters and Analysis of Effect of Variables in the Dead Burning of Magnesite in Rotary Kiln

    NASA Astrophysics Data System (ADS)

    Chakrabarti, B. K.

    The challenges of improving sintered MgO raw materials with special high temperature properties demand higher temperature calcination. In the process of dead burning of magnesite (DBM) in rotary kiln, the heat expenditures were found to be mainly due to dead burning of magnesite, loss through exhaust gases, loss through kiln shell by radiation & convection, clinker exit etc. The calcination process is highly energy intensive and involves various interdependent variable factors. An attempt was made to build a model and a screening design of experiment was performed with few process variables to identify the greatest effect of variables on the response quality. The design variables chosen were raw magnesite (RM) feed rate, kiln rotation (RPM), fuel consumption and burning zone temperature (BZT). The response variables were exit gas temperature and density of dead burnt magnesite (DBM). A fractional factorial design was used to keep the number of experimental runs to a minimum. ANOVA and normal plots were used to evaluate the effects of different variable factors on the sensory/response properties. The Experimental Design, ANNOVA, Response surface etc. given an insight of dead burning of magnesite in rotary kiln. This work had enabled us to correlate the BZT, RPM, RM feed with the exit gas temp and density of magnesite produced. The result opens up an avenue to look into the optimum region of operations within the ranges of variables considered in order to minimize the exhaust gas temp. and to maximize the density of the DBM produced.

  4. H.R. 4984: A Bill to amend the Solid Waste Disposal Act to regulate the use of hazardous waste as fuel for energy recovery, the operation of cement kilns that burn hazardous waste as fuel, the disposal of cement kiln dust waste, and related activities. Introduced in the House of Representatives, One Hundred Third Congress, Second Session, August 18, 1994

    SciTech Connect

    1994-12-31

    The report H.R. 4984 is a bill to amend the Solid Waste Disposal Act to regulate the use of hazardous waste as fuel for energy recovery, the operation of cement kilns that burn hazardous waste as fuel, the disposal of cement kiln dust waste. The proposed legislative text is provided.

  5. Evaluating Employability Skills: Employer and Student Perceptions

    ERIC Educational Resources Information Center

    Saunders, Venetia; Zuzel, Katherine

    2010-01-01

    Graduate employability is a key issue for Higher Education. In this two-part study student employability skills have been evaluated from the perspective of sandwich students and graduates in biomolecular science, and their employers. A strong correlation was found between employer and sandwich student/graduate perceptions of the relative…

  6. Kiln control

    NASA Astrophysics Data System (ADS)

    Adams, Bob

    2016-03-01

    In reply to the feature article “Bubble signatures revealed in antique artefacts” by Stephen C Wallace and Geraldine Kenney-Wallace (January pp34-38) about how physics can help to tell a real antique porcelain object from a fake.

  7. Particle capture device

    DOEpatents

    Jayne, John T.; Worsnop, Douglas R.

    2016-02-23

    In example embodiments, particle collection efficiency in aerosol analyzers and other particle measuring instruments is improved by a particle capture device that employs multiple collisions to decrease momentum of particles until the particles are collected (e.g., vaporized or come to rest). The particle collection device includes an aperture through which a focused particle beam enters. A collection enclosure is coupled to the aperture and has one or more internal surfaces against which particles of the focused beam collide. One or more features are employed in the collection enclosure to promote particles to collide multiple times within the enclosure, and thereby be vaporized or come to rest, rather than escape through the aperture.

  8. Analysis of metals in cement kiln dust using the lithium fusion method

    SciTech Connect

    Schoenberger, R.J.; Buchanan, C.E. Jr.

    1994-12-31

    The analysis of metals using hot plate, microwave and lithium borate fusion digestion has been investigated for four samples cement kiln dust. Results of analysis show that the standard hot plate digestion yields the lowest results or recovery of metals. Microwave digestion generally shows a slightly higher recovery of metals, but the significance of the difference can not be calculated until more samples are analyzed. Because of the presence of silica and alumina, the fusion method shows significantly higher recovery for chromium, nickel, zinc, potassium, calcium, and iron. The fusion vaporizes some constituents; lead, sulfur, vanadium and therefore the method is not usable for those constituents. The impact on cadmium is unclear and more investigation is needed.

  9. Steelworks residues and the Waelz kiln treatment of electric arc furnace dust

    SciTech Connect

    Strohmeier, G.; Bonestell, J.E.

    1996-04-01

    Electric arc furnace dust with a combined zinc and lead content in excess of 20% renders the dumping of this material impossible in many countries, for both statutory and financial reasons. In the Waelz process, dust is treated in a rotary kiln where it is heated to approximately 1,200 C. lead and zinc are volatilized under reducing conditions and collected as fine dust in the off-gas dust collection system. The oxide recovered in the off-gas filters contains approximately 55% Zn and up to 10% Pb, and is ideal feedstock for the Imperial Smelting furnace for lead/zinc recovery. The remaining slag is inert and unleachable so that it can be used as a building aggregate.

  10. Comparison between drying of timber in a solar dryer and in an electrically-heated kiln

    SciTech Connect

    Ong, K.S.

    1997-03-01

    Solar dryers have been considered for timber drying in a number of countries because of the expected savings in drying costs. From a review of past works on solar, natural, and conventional drying it was observed that while solar dryers were able to dry timber faster compared to natural drying, the difference was only marginal in some instances. The drying rates are expected to be dependent upon ambient conditions in which the dryers are operated. Solar dryers would operate more efficiently in countries with low humidity than in tropical regions. Thus the thermal performance and also the economics of solar dryers is country dependent. In the present paper, a comparison of the drying rates obtained with a solar dryer is made with that obtained with an electrically operated drying kiln.

  11. Case study of grate-chain degradation in a Grate-Kiln process

    NASA Astrophysics Data System (ADS)

    Nilsson, Erik A. A.; Pettersson, L.; Antti, M.-L.

    2013-12-01

    Austenitic stainless steels are often used in high temperature applications due to their resistance to corrosion. Grate-Kiln processes that sinter iron ore pellets use grate-chains which are made of austenitic stainless steel to withstand the severe environment. It has been shown, however, that the grate-chain is affected by several degrading mechanisms in the harsh environment of the sintering process. A grate-chain that has been in service for 8 months was investigated in order to find the mechanisms of degradation. Results show that slag products are accumulated on the grate-chain and interact with the steel as hot corrosion. The stainless steel is believed to be sensitized against inter-granular attack by carburization followed by inter-granular attack. The resistance towards degradation seems to decrease with time which is suggested to be caused by depletion of chromium.

  12. [Assessment on PCBs wastes treatment technologies including incineration, cement kiln and secure landfill].

    PubMed

    Xing, Ying; Lü, Yong-Long; Shi, Ya-Juan; Wang, Tie-Yu; Luo, Wei; Wang, Guang; Ma, Hu; Sun, Ya-Mei

    2007-03-01

    Analytic hierarchy process and a specialist investigation were applied to value the three PCBs treatment technologies qualitatively and quantitatively, in which the environmental, technological, social and economic factors were considered. The most important factor is thought to be environmental impact. Incineration is proved to be the most suitable technology in this period according to the research. For the high concentration of PCBs pollutants, or the low concentration of PCBs pollutants with good economic performance and large quantity of waste, incineration is considered the best. For the low concentration of PCBs pollutants in the area with bad economic performance and with little quantity of waste, cement kiln and landfill are thought to be suitable. It is also suggested that pollutants be treated at the nearest place. What's more, the measures to improve the three technologies are discussed and the policy comments on PCBs treatment are presented.

  13. Physicochemical and microbiological characterization of cement kiln dust for potential reuse in wastewater treatment.

    PubMed

    Salem, W M; Sayed, W F; Halawy, S A; Elamary, R B

    2015-09-01

    Cement kiln dust (CKD), a byproduct of cement manufacturing process, was collected from Misr Cement Co. at Qena, Egypt. CKD was characterized by X-ray diffraction and FTIR analysis. This byproduct was investigated for its physical-chemical characters, antibacterial activities on sewage water and the presence of nematode, parasites and algae in the treated water. The efficiency of CKD-treated water was also examined on Hibiscus sabdarriffa seed germination. Total bacteria, total and fecal coliform, as well as fecal streptococci were completely inhibited by CKD. Interestingly, zinc, manganese, iron, nickel and lead were completely absent from sewage water as these metals precipitated after treatment with 10gl(-1) CKD. On the other hand, among all the tested plant criteria, only root length was significantly reduced by 55% and 15% after zero and 3 days of CKD addition respectively compared to control. Furthermore, plant lipid peroxidation showed no significant differences between treated sewage water and control after zero and 3 days time addition of CKD. Catalase enzyme activity showed significant decrease by 56% and 64%, while peroxidase activity significantly increased up to 49% and 63% compared to untreated sewage after zero and 3 days of treatment, respectively. The absorption of lead, iron and copper by treated and untreated plants showed no significant differences. Chromium ions were highly absorbed (0.075mgl(-1)) by plants irrigated only with treated sewage water at zero time, and decreased gradually to 0.018mgl(-1) after 3 days of CKD addition. This study highlighted the efficiency of cement kiln dust as an antibacterial agent and its ability of scavenging heavy metals leading to the use of treated sewage water in activities such as crop irrigation.

  14. Screening of brick-kiln area soil for determination of heavy metal Pb using LIBS.

    PubMed

    Pandhija, Shiwani; Rai, A K

    2009-01-01

    Rapid measurement of heavy metals in soil is an important factor in modeling the effect of industrial pollution on agricultural soil. Conventional methods of heavy metal analysis are relatively slow in terms of measurement/analysis time and sample preparation time with the requirement of skilled manpower. Our results highlight the quantitative analysis of toxic metal lead (Pb), for the first time, in an Indian agricultural soil, in the vicinity of brick-kiln area, Phaphamau, near Allahabad, India, by using a novel technique named as Laser-induced breakdown spectroscopy (LIBS). LIBS spectra of soil has been recorded in the wavelength range from ultraviolet (UV) to infrared region (200-1,100 nm). The suitability of Pb lines for drawing the calibration curve is checked and realized, for the first time, that 220.3 nm, which is observed in the UV region of LIBS spectra, is completely interference free and best suited for the quantification of trace amount of Pb in soil instead of any other Pb lines, because it has best linear regression coefficient and smallest standard deviation of the background signal. In the present work the detection limit for Pb in soil is found to be 45 ppm. Based on the present work the concentration of Pb in agricultural soil of brick-kiln area in Phaphamau is found to be congruent with 570 ppm, which is more than the regulatory standards imposed by US Environmental Protection Agency (400 ppm) for the presence of lead in soil, therefore, it is of great concern to us.

  15. The primary evaluation and characterization of obsolete DDT pesticide from a precalciner of a cement kiln.

    PubMed

    Li, Yang; Wang, Qi; Huang, Qifei; He, Jie

    2014-01-01

    1,1,1-Trichloro-2,2-bi(4-chlorophenyl)ethane (DDT) pesticide that has been extensively used in agriculture in China in the last century, and even now, has been banned from all purposes. The disposal of obsolete DDT pesticide has been an urgent task for the Chinese government. In order to evaluate the feasibility of co-processing DDT in the current new style dry-process rotary kiln with a precalciner as the feeding point, the destruction efficiency (DE) of DDTs (including p,p(')-DDT, o,p(')-DDT, p,p(')-DDE and p,p(')-DDD), proportion of DDTs in the combustion residue and exhaust gas, and the release of chlorine were studied under different operating conditions of temperature, oxygen content and gas retention time in the laboratory. The DE of DDTs exceeded 99% when the temperature was over 800 °C with enough oxygen. As the temperature increased from 600 °C to 1200 °C, the proportion of p,p(')-DDD increased and p,p(')-DDT decreased but still the main effective component remained in the combustion residue. In the exhaust gas, the most dominant phenomenon was the rapid increase in p,p(')-DDE concentration as the temperature increased. The release of chlorine reached a peak between 800 °C and 900 °C. It was found that the oxygen content had a positive correlation with the process of dechlorination. The proportion of p,p(')-DDE increased as the oxygen content was increased in the exhaust gas. The gas retention time had almost no influenced on the DE of DDTs, but affected the degradation extent of DDTs in the gas phase. These experiments showed that co-processing of obsolete DDT pesticide in cement kiln precalciners is feasible.

  16. Draft Whole-Genome Sequence of the Alkaliphilic Alishewanella aestuarii Strain HH-ZS, Isolated from Historical Lime Kiln Waste-Contaminated Soil.

    PubMed

    Salah, Zohier B; Rout, Simon P; Humphreys, Paul N

    2016-12-29

    Here, we present the whole-genome sequence of an environmental Gram-negative Alishewanella aestuarii strain (HH-ZS), isolated from the hyperalkaline contaminated soil of a historical lime kiln in Buxton, United Kingdom.

  17. Novel method of reducing transient emissions from rotary-kiln incinerators through modified waste packaging. Rept. for Mar 90-May 92

    SciTech Connect

    Lemieux, P.M.; Linak, W.P.; Wendt, J.O.L.

    1992-01-01

    The paper gives results of tests on a 73 kW pilot-scale rotary kiln incinerator simulator to examine the effect of modified waste packaging on the ability of the incineration system to respond to transients imposed due to batch charging of volatile liquid surrogate hazardous wastes bound on corncob sorbents. Normally, the waste container ruptures soon after its introduction into the kiln, rapidly releasing any contained volatile materials. This rapid release of combustibles has the potential to locally deplete available oxygen supplied by the main burner. This can lead to a transient puff of unburned material that must be dealt with by downstream equipment, such as an afterburner. Innovative waste packaging methods were used to delay the time required for waste vaporization, which significantly decreased the measured amount of unburned material exiting the kiln. This concept has advantageous implications for rotary kiln incinerators as a way to both reduce transient emissions and increase the feed rate of containerized liquids.

  18. Draft Whole-Genome Sequence of the Alkaliphilic Alishewanella aestuarii Strain HH-ZS, Isolated from Historical Lime Kiln Waste-Contaminated Soil

    PubMed Central

    Salah, Zohier B.; Rout, Simon P.

    2016-01-01

    Here, we present the whole-genome sequence of an environmental Gram-negative Alishewanella aestuarii strain (HH-ZS), isolated from the hyperalkaline contaminated soil of a historical lime kiln in Buxton, United Kingdom. PMID:28034857

  19. 40 CFR Table Aa-2 to Subpart Aa of... - Kraft Lime Kiln and Calciner Emissions Factors for Fossil Fuel-Based CH4 and N2O

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Kraft Lime Kiln and Calciner Emissions... and Calciner Emissions Factors for Fossil Fuel-Based CH4 and N2O Fuel Fossil fuel-based emissions factors (kg/mmBtu HHV) Kraft lime kilns CH4 N2O Kraft calciners CH4 N2O Residual Oil 0.0003 Distillate...

  20. 40 CFR Table Aa-2 to Subpart Aa of... - Kraft Lime Kiln and Calciner Emissions Factors for Fossil Fuel-Based CH4 and N2O

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Kraft Lime Kiln and Calciner Emissions... and Calciner Emissions Factors for Fossil Fuel-Based CH4 and N2O Fuel Fossil fuel-based emissions factors (kg/mmBtu HHV) Kraft lime kilns CH4 N2O Kraft calciners CH4 N2O Residual Oil 0.0003 Distillate...

  1. 40 CFR Table Aa-2 to Subpart Aa of... - Kraft Lime Kiln and Calciner Emissions Factors for Fossil Fuel-Based CH4 and N2O

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Kraft Lime Kiln and Calciner Emissions... and Calciner Emissions Factors for Fossil Fuel-Based CH4 and N2O Fuel Fossil fuel-based emissions factors (kg/mmBtu HHV) Kraft lime kilns CH4 N2O Kraft calciners CH4 N2O Residual Oil 0.0003 Distillate...

  2. 40 CFR Table Aa-2 to Subpart Aa of... - Kraft Lime Kiln and Calciner Emissions Factors for CH4 and N2O

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Kraft Lime Kiln and Calciner Emissions... Manufacturing Pt. 98, Subpt. AA, Table AA -2 Table AA-2 to Subpart AA of Part 98—Kraft Lime Kiln and Calciner... CH4 N2O Kraft calciners CH4 N2O Residual Oil (any type) 0.0027 0 0.0027 0.0003 Distillate Oil...

  3. Evaluation of primary air vitiation for nitric oxide reduction in a rotary cement kiln. Volume 1. Technical report. Final report, June 1983-September 1985

    SciTech Connect

    Benson, R.C.; Hunter, S.C.

    1986-10-01

    The report gives results of tests to evaluate combustion modifications for nitric oxide (NO) reduction and cement-product quality in a pilot-scale long-dry-process cement kiln firing pulverized coal. The kiln is rated at 11.35 kg/s (1080 tons/day) of cement with a thermal input rate of 70.3 MW (240 million Btu/hr). Of the combustion modifications evaluated in previous studies, vitiation of the primary air with inert gas (nitrogen) was considered the best alternative for NO reduction on a pilot-scale kiln. The percent reduction was established from a reference baseline of 1050 ppm (corrected to 3% O/sub 2/) and a kiln exit oxygen of 1.82%. The NO volumetric emissions were lowered to 880 ppm (corrected to 3% O/sub 2/) with a kiln exit oxygen of 0.7%. NOx reductions during the short-term nitrogen injection tests were about 25-30% with no adverse effects on product quality. Because of the interacting feed chemistry/kiln operations, it was not possible to clearly isolate the effect of nitrogen injection.

  4. Evaluation of primary air vitiation for nitric oxide reduction in a rotary cement kiln. Volume 2. Data supplement A. Final report, June 1983-September 1985

    SciTech Connect

    Benson, R.C.; Frohoff, R.A.; Parker, N.R.

    1986-10-01

    The report gives results of tests to evaluate combustion modifications for nitric oxide (NO) reduction and cement-product quality in a pilot-scale long-dry-process cement kiln firing pulverized coal. The kiln is rated at 11.35 kg/s (1080 tons/day) of cement with a thermal input rate of 70.3 MW (240 million Btu/hr). Of the combustion modifications evaluated in previous studies, vitiation of the primary air with inert gas (nitrogen) was considered the best alternative for NO reduction on a pilot-scale kiln. The percent reduction was established from a reference baseline of 1050 ppm (corrected to 3% O/sub 2/) and a kiln exit oxygen of 1.82%. The NO volumetric emissions were lowered to 880 ppm (corrected to 3% O/sub 2/) with a kiln exit oxygen of 0.7%. NOx reductions during the short-term nitrogen injection tests were about 25-30% with no adverse effects on product quality. Because of the interacting feed chemistry/kiln operations, it was not possible to clearly isolate the effect of nitrogen injection.

  5. Fate of trace metals in a rotary-kiln incinerator with a single-stage ionizing wet scrubber. Volume 1. Technical results

    SciTech Connect

    Fournier, D.J.; Waterland, L.R.

    1991-07-01

    A series of pilot-scale incineration tests was performed at EPA's Incineration Research Facility (IRF) in Jefferson, Arkansas, to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with an ionizing wet scrubber (IWS) for particulate and acid gas control. Test variables were kiln temperature, ranging from 816 to 927 C (1500 to 1700 F); afterburner temperature, ranging from 982 to 1204 C (1800 to 2200 F); and feed chlorine content, ranging from 0 to 8 percent. The test program evaluated the fate of five hazardous constituent trace metals (arsenic, barium, cadmium, chromium, and lead) and four nonhazardous constituent trace metals (bismuth, copper, magnesium, and strontium). The test results indicate that cadmium and bismuth were relatively volatile, with an average of less than 40 percent discharged with the kiln ash. Arsenic, barium, chromium, copper, lead, magnesium, and strontium were relatively nonvolatile, with an average of greater than 80 percent discharged with the kiln ash. Observed relative metal volatilities generally agreed with the volatilities predicted based on vapor pressure/temperature relationships, with the exception of arsenic which was much less volatile than predicted. The volatility of cadmium, bismuth, and lead increased as kiln temperature was increased; the discharge distributions of the remaining metals were not significantly affected by changes in kiln temperature. Apparent scrubber collection efficiencies for the metals averaged 22 to 71 percent, and were generally higher for the less volatile metals. The overall average metal collection efficiency was 43 percent.

  6. Reducing firing of an early pottery making kiln at Batán Grande, Peru: A Mössbauer study

    NASA Astrophysics Data System (ADS)

    Wagner, U.; Gebhard, R.; Häusler, W.; Hutzelmann, T.; Riederer, J.; Shimada, I.; Sosa, J.; Wagner, F. E.

    1999-11-01

    Material from field firing experiments using a 2,700-year old Formative kiln at Batán Grande, Peru, was studied by X-ray diffraction and Mössbauer spectroscopy. The experiments explore the technology involved in producing the gray and black reduced ware for which Cupisnique and other Formative ceramics are justly known. During firing, the iron-bearing compounds in clays undergo characteristic changes which depend on kiln temperature and atmosphere. These changes can be observed in the Mössbauer spectra. By comparing spectra of an appropriate clay fired in field experiments and in the laboratory with the spectra of ancient ceramics, a description of Formative firing techniques in a reducing environment is attempted.

  7. Comparison of experimental results with analytical solutions and two dimensional model of oak drying in an evacuated kiln

    SciTech Connect

    Audebert, P.; Temmar, A.

    1997-05-01

    In continuation of a series of tests, the original results of oak drying in an evacuated kiln are presented here for different plate temperatures and for various pressures in the kiln. These results include more particularly the drying curves, the evolution of temperature, of moisture and of pressure in and on the wood. They evidence the pressure and the levels of temperature occurring in the wood during the drying period. These results also allow the development of two types of drying models: a simple monodimensional model of drying curves from the analytical solutions of the equations of water diffusion in the wood and, moreover, a model, in two dimensions, of temperature, moisture and pressure fields in the wood by applying the finite element method. The boundary conditions of the second model can be fixed with precision thanks to the results of the first model. In both cases, the proposed solutions are justified by experimental results.

  8. Pollutant formation and emissions from cement kiln stack using a solid recovered fuel from municipal solid waste.

    PubMed

    Conesa, Juan A; Rey, Lorena; Egea, Silvia; Rey, Maria D

    2011-07-01

    The thermal decomposition of a solid recovered fuel (SRF) has been studied by two techniques. First, laboratory-scale experiments were performed in a horizontal furnace in which different atmospheres were studied to analyze the dioxins and furans (PCDD/Fs) evolved from the decomposition of the material. Sulfur presence was revealed to be important in PCDD/Fs formation. In the second technique, the emissions of various pollutants (PAHs, PCDD/Fs, metals, acid gases, etc.) were determined in a cement kiln fed on different proportions of SRF material, and where a maximum feed rate of 15000 kg SRF/h was achieved. In the laboratory furnace the dioxin toxicity revealed a maximum when the amount of oxygen in the atmosphere increased until approximately stoichiometric conditions. In the cement kiln, all emitted pollutants were under the legal limits. No correlation between SRF input and metal emission was observed.

  9. Industrial hazardous waste treatment featuring a rotary kiln and grate furnace incinerator: a case study in China.

    PubMed

    Ma, Pan; Ma, Zengyi; Yan, Jianhua; Chi, Yong; Ni, Mingjiang; Cen, Kefa

    2011-10-01

    As one of the fastest developing countries, China is facing severe problems concerning hazardous waste treatment and disposal. This paper presents a new incineration technology and demonstration project in eastern China. The incineration system includes a rotary kiln, a grate furnace for burning out the kiln residue and a flue gas post-combustion chamber. Flue gas treatment and emission control is based on: a quench tower, followed by dry hydrated lime and activated carbon injection, a dual bag filter system, and a wet scrubber. It demonstrated that this incineration technology can effectively dispose of industrial hazardous waste with variable and complex characteristics. Gas emissions meet the demands of the Chinese Environmental Protection Association standard.

  10. Secular variation between 5 and 10c CE in Japan: remeasurements of 2000 samples collected between 1960-70's from Sueki earthenware kilns in Osaka.

    NASA Astrophysics Data System (ADS)

    Shibuya, H.; Mochizuki, N.; Hatakeyama, T.

    2015-12-01

    In Japan, archeomagnetic measurements are vigorously developed for years, though it is not well known to paleomagnetism community in english. One of the works is massive archeomagnetic study of Suemura kiln group carried out in Osaka University in 1960's to early 70's. More than 500 kilns were excavated in Sakai city and vicinities, Osaka Prefecture, Japan. The kiln group is called as Suemura Kilns, and are for Sueki earthenware of 5c to 10c CE. About 300 kilns were sampled and most of the samples were measured at the time, and the results are reported in e.g. Hirooka (1971) and Shibuya (1980). However, the results have significant scatter in direction, which may be due to the limitation of old astatic magnetometer measurements and handwriting graphic determination of magnetic direction, and/or the lack of demagnetization. We recently inherited many of those samples and remeasured them with spinner magnetometer applying alternation field demagnetization (afd). The magnetizations are generally very stable, as usual as other archeomagnetic samples, and afd does not change the magnetic direction mostly. However, significant number of sites show large scatter in magnetic directions, which might be due to the wrong identification of kiln floor or disturbance at the time of collapsing or excavation. Taking kilns of α95<4o, we recovered 131 paleomagnetic directions. Although third of them are dated by pottery shape chronology, the range of each pottery style is not precisely known and the relation of the baked floor and the potteries excavated around kilns are not always clear. The carbon dating of those kilns are very scares. Thus we first try to draw secular variation curve in declination-inclination plot. With the rough ages of those kilns, it is pretty easy to draw the SVC. It is also numerically determined taking the distance of each direction from nearest point in SVC and the velocity change of the SVC as penalty function, within a couple of degrees in the error

  11. Heavy metals in brick kiln located area using atomic absorption spectrophotometer: a case study from the city of Peshawar, Pakistan.

    PubMed

    Ishaq, M; Khan, Murad Ali; Jan, F Akbar; Ahmad, I

    2010-07-01

    Environmental pollution is one of the burning issues of the world. In developed countries, there are lot of awareness about the environment and the impact of various industries on their life and surroundings. A little has been done in this direction in developing countries. In Pakistan, a big problem is the rapid conglomeration of the brick kilns in the outskirts of nearly all the urban centers to cope with the rapid construction work in big cities. A huge amount of low-grade coal or rubber tires is used as fuel in a very non-scientific manner. The purpose of the present study was to look into the impact of the brick kilns on the different aspects of environmental pollution caused by these kilns. Concentration of metals Cu, Co, Zn, Pb, Cr, Ni, Cd, and Mn were measured on 36 soil samples collected from the area and the same number of plant samples in order to establish the distribution of heavy metals in the area and to determine the effect of this distribution on the surrounding atmosphere and the possible effects on human life.

  12. An engineering assessment of the burning of the combustible fraction of construction and demolition wastes in a redundant brick kiln.

    PubMed

    Chang, N B; Lin, K S; Sun, Y P; Wang, H P

    2001-12-01

    This paper confirms both technical feasibility and economic potential via the use of redundant brick kilns as an alternative option for disposal of the combustible fractions of construction and demolition wastes by a three-stage analysis. To assess such an idea, one brick kiln was selected for performing an engineering feasibility study. First of all, field sampling and lab-analyses were carried out to gain a deeper understanding of the physical, chemical, and thermodynamic properties of the combustible fractions of construction and demolition wastes. Kinetic parameters for the oxidation of the combustible fractions of construction and demolition wastes were therefore numerically calculated from the weight loss data obtained through a practice of thermogravimetric analyzer (TGA). Secondly, an engineering assessment for retrofitting the redundant brick kiln was performed based on integrating several new and existing unit operations, consisting of waste storage, shredding, feeding, combustion, flue gas cleaning, and ash removal. Such changes were subject to the operational condition in accordance with the estimated mass and energy balances. Finally, addressing the economic value of energy recovery motivated a renewed interest to convert the combustible fractions of construction and demolition wastes into useful hot water for secondary uses.

  13. New directional results and determination of absolute archaeointensity using both the classical Thellier and the multi-specimen procedures for two kilns excavated at Osterietta, Italy

    NASA Astrophysics Data System (ADS)

    Tema, Evdokia; Camps, Pierre; Ferrara, Enzo

    2014-05-01

    A detailed rock-magnetic and archaeomagnetic study has been carried out on two rescue excavation kilns discovered during the works to expand a highway at the location of Osterietta, in Northen Italy. Systematic archaeomagnetic sampling was carried out collecting 15 samples from the first kiln (OSA) and 8 samples from the second kiln (OSB), all of them oriented in situ with a magnetic compass and an inclinometer. Magnetic mineralogy measurements have been carried out in order to determine the main magnetic carrier of the samples and to check their thermal stability. Standard thermal demagnetization procedures have been used to determine the archaeomagnetic direction registered by the bricks during their last firing. Demagnetization results show a very stable characteristic remanent magnetization (ChRM). We averaged the directions for each kiln separately and calculated the statistical parameters assuming a Fisherian distribution. The archaeointensity of both kilns has also been recovered with both the classical Thellier-Thellier method and the multi-specimen procedure (MSP-DSC). During the Thellier experiments, regular partial thermoremanent magnetization checks have been performed and the effect of the anisotropy of the thermoremanent magnetization (TRM) and cooling rate upon TRM intensity acquisition have been investigated in all samples. The multi-specimen procedure was performed with a very fast-heating oven developed at Montpellier (France). The intensity results obtained from both methods have been compared and the full geomagnetic field vector determined for each kiln has been used for archaeomagnetic dating. The obtained results show that the kilns were almost contemporaneous and their last use occurred in the 1750-1850 AD time interval.

  14. Rapid coastal subsidence in the central Ganges-Brahmaputra Delta (Bangladesh) since the 17th century deduced from submerged salt-producing kilns

    NASA Astrophysics Data System (ADS)

    Hanebuth, T. J.; Kudrass, H.; Linstädter, J.; Islam, B.; Zander, A. M.

    2013-12-01

    The densely populated low lying Ganges-Brahmaputra Delta is highly vulnerable to the global sea-level rise. In order to estimate the subsidence of the delta over historical time scales, we examined submerged salt-producing kiln sites in the coastal Sundarbans. These kilns were built just above the previous winterly spring high-tide level, but are currently located ~155 × 15 cm below the corresponding modern level. According to optically stimulated luminescence (OSL) dating, the kilns were ultimately fired ~300 years ago (1705 × 35 AD) and salt production was terminated abruptly by a catastrophic event (major cyclone), which affected the kiln sites at different levels and locations. Two particular buried mangrove root horizons 80 cm below this kiln level also indicate catastrophic scenarios (probably subsidence events related to a regional earthquake). AMS-14C ages measured on the charcoal layers at the kiln's bases and on these associated mangrove stump horizons support the OSL dates. Based on the respective elevations of these kiln and mangrove palaeo-horizons and on the ages, the 300-year-average rate of sinking of the outer delta is 5.2 × 1.2 mm/a, which includes 0.8 mm/a of eustatic sea-level rise over this historical period. Expecting further acceleration of the eustatic sea-level rise of up to 7 mm/a, we calculate a rise in relative sea level of up to 8.9 × 3.3 mm/a for the next few decased, which will dramatically aggravate the already present problematic situation. Only a prudently-managed control of sediment accretion will keep southern Bangladesh above the sea level. (Hanebuth et al., Geology, Sept 2013, doi: 10.1130/G34646.1.)

  15. Employers' Views on Youth Literacy and Employability

    ERIC Educational Resources Information Center

    Macey, Emma

    2013-01-01

    This report looks at whether employers think schools are equipping young people with the literacy skills required for the workplace. It is primarily based on secondary literature sources and introductory conversations with a small sample of key employers and agencies. A complementary report presents evidence on young people's views on literacy and…

  16. Employing Discourse: Universities and Graduate "Employability"

    ERIC Educational Resources Information Center

    Boden, Rebecca; Nedeva, Maria

    2010-01-01

    What constitutes graduate employability is discursively framed. In this paper we argue that whilst universities in the UK have long had an involvement in producing useful and productive citizens, the ongoing neoliberalisation of higher education has engendered a discursive shift in definitions of employability. Traditionally, universities regarded…

  17. Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

    PubMed Central

    Yang, Yufei; Xue, Jingchuan; Huang, Qifei

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H) was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF) of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V) and mainly existed as Mg3(AsO4)2, Ca3(AsO4)2, and Na2HAsO4. PMID:24223030

  18. Characterization and utilization of cement kiln dusts (CKDs) as partial replacements of Portland cement

    NASA Astrophysics Data System (ADS)

    Khanna, Om Shervan

    The characteristics of cement kiln dusts (CKDs) and their effects as partial replacement of Portland Cement (PC) were studied in this research program. The cement industry is currently under pressure to reduce greenhouse gas (GHG) emissions and solid by-products in the form of CKDs. The use of CKDs in concrete has the potential to substantially reduce the environmental impact of their disposal and create significant cost and energy savings to the cement industry. Studies have shown that CKDs can be used as a partial substitute of PC in a range of 5--15%, by mass. Although the use of CKDs is promising, there is very little understanding of their effects in CKD-PC blends. Previous studies provide variable and often conflicting results. The reasons for the inconsistent results are not obvious due to a lack of material characterization data. The characteristics of a CKD must be well-defined in order to understand its potential impact in concrete. The materials used in this study were two different types of PC (normal and moderate sulfate resistant) and seven CKDs. The CKDs used in this study were selected to provide a representation of those available in North America from the three major types of cement manufacturing processes: wet, long-dry, and preheater/precalciner. The CKDs have a wide range of chemical and physical composition based on different raw material sources and technologies. Two fillers (limestone powder and quartz powder) were also used to compare their effects to that of CKDs at an equivalent replacement of PC. The first objective of this study was to conduct a comprehensive composition analysis of CKDs and compare their characteristics to PC. CKDs are unique materials that must be analyzed differently from PC for accurate chemical and physical analysis. The present study identifies the chemical and physical analytical methods that should be used for CKDs. The study also introduced a method to quantify the relative abundance of the different

  19. Re-cycling of sugar-ash: a raw feed material for rotary kilns.

    PubMed

    Kantiranis, Nikolaos

    2004-01-01

    Large amounts of sugar-ash, a material rich in calcium carbonate, are produced as a by-product in the Greek Sugar Industry. This work explores the possibility of re-cycling sugar-ash for use in the lime industry. A representative sample of sugar-ash from the Plati Imathias sugar plant was studied by PXRD, TG/DTG, calcination experiments at temperatures between 650 and 1150 degrees C and experiments to determine the quality of the quicklime produced at temperatures between 850 and 1150 degrees C following methods described in ASTM C110 standard. The sugar-ash was found to consist of 90 wt% calcium rich minerals (calcite and monohydrocalcite) and 10 wt% amorphous material. Traces of quartz were also detected. The quicklime of highest quality was produced at 950 degrees C. It is concluded that this "useless" material (sugar-ash) can be re-cycled for use in rotary kilns in the lime industry at calcination temperatures up to 950-1000 degrees C.

  20. Influence of cement kiln dust substitution on the mechanical properties of concrete

    SciTech Connect

    Shoaib, M.M.; Balaha, M.M.; Abdel-Rahman, A.G.

    2000-03-01

    Large quantities of cement kiln dust (CKD) are produced during the manufacture of cement clinker by the dry process. The technical and economical problems that arise for the semi-manufacture of raw materials used, energy and transportation of dust from the plant to outside, as well as the severe pollution to the surrounding atmosphere show the necessity of utilizing cement dust as one of the main objectives of the investigation. The cement dust contains a mixture of raw feed as well as calcined materials with some volatile salts. The aim of the present work is to study the effect of cement dust substitution instead of ordinary Portland cement (OPC), blast furnace slag cement (BFSC), and sulfate resistance cement (SRC) on the mechanical properties of some concrete mixes containing them, and also, to determine the optimum quantity of CKD which could be recycled in the manufacture of these types of cements. Useful conclusions and recommendations concerning the use of different amounts of CKD in the production of some blended cements as a partial substitution from different types of cements were obtained.

  1. Comparative performance of cement kiln dust and activated carbon in removal of cadmium from aqueous solutions.

    PubMed

    El-Refaey, Ahmed A

    2016-01-01

    This study compared the performance of cement kiln dust (CKD) as industrial byproduct and commercially activated carbon (AC) as adsorbent derived from agricultural waste for the removal of cadmium (Cd(2+)) from aqueous solutions. CKD and AC were characterized by Fourier transform infrared (FTIR) and scanning electron microscopy (SEM) and surface areas demonstrate the differences of physicochemical properties. Batch equilibrium experiments were conducted for various intervals extended to 96 h at 20, 25 and 30°C to investigate the efficiency of the sorbents in the removal of Cd(2+). CKD expressed high affinity for removal of Cd(2+) and was not affected by temperature, while AC was significantly affected, which reflects dissimilarity in the retention mechanisms defendant in CKD and those pursued by AC. The results were explained by changes of FTIR and SEM images before and after sorption experiments. The suggestion is that electrostatic ion exchange and complex reactions are the main mechanisms for Cd(2+) removal. The kinetic data were evaluated by fractional power, Elovich, pseudo-first order and pseudo-second-order kinetic models. The pseudo-second-order kinetic model was found to correlate with the experimental data well. These results revealed that CKD can be used as a cost-effective and efficient sorbent for Cd(2+) removal in comparison with AC.

  2. Equilibrium analysis for heavy metal cation removal using cement kiln dust.

    PubMed

    El Zayat, Mohamed; Elagroudy, Sherien; El Haggar, Salah

    2014-01-01

    Ion exchange, reverse osmosis, and chemical precipitation have been investigated extensively for heavy metal uptake. However, they are deemed too expensive to meet stringent effluent characteristics. In this study, cement kiln dust (CKD) was examined for the removal of target heavy metals. Adsorption studies in completely mixed batch reactors were used to generate equilibrium pH adsorption edges. Studies showed the ability of CKD to remove the target heavy metals in a pH range below that of precipitation after an equilibrium reaction time of 24 h. A surface titration experiment indicated negative surface charge of the CKD at pH below 10, meaning that electrostatic attraction of the divalent metals can occur below the pH required for precipitation. However, surface complexation was also important due to the substantive metal removal. Accordingly, a surface complexation model approach that utilizes an electrostatic term in the double-layer description was used to estimate equilibrium constants for the protolysis interactions of the CKD surface as well as equilibria between background ions and the sorbent surface. It was concluded that the removal strength of adsorption is in the order: Pb > Cu > Cd. The experiments were also supported by Fourier transform infrared spectroscopy (FTIR).

  3. Full scale treatment of ASR wastes in a modified rotary kiln.

    PubMed

    Mancini, G; Viotti, P; Luciano, A; Raboni, M; Fino, D

    2014-11-01

    A plant, designed for the thermo-valorisation of tyres, was specifically modified in order to treat Automobile Shredder Residue (ASR). Results from two full-scale combustion experiments, carried out on large ASR feeding lots (thousands of tons) indicate the proposed technology as a potential route to help the fulfilling of impending 95% reuse and recovery target set by the End of life Vehicle (ELV) Directive (January 2015). The paper describes the main operational troubleshot occurred during the first experiment (emissions at the stack out of regulatory limits and problems of clogging on the conveyer belt) and the consequent upgrading solutions (pre-treatment, introduction of waste double low-flow screw feeder and a cyclone prior to the main fan, modification of rotatory kiln inlet) adopted to allow, during the second long-term experiment, a continuous basis operation of the plant in full compliance with the discharge limit to the atmosphere. Characterization of both ASR and combustion residues allowed to quantify a 18% of combustion residues as not dangerous waste while only the 2% as hazardous one. A pre-treatment for the reduction of fines in the ASR was recommended in order to achieve the required energy recovery efficiency.

  4. Determination of the optimal area of waste incineration in a rotary kiln using a simulation model.

    PubMed

    Bujak, J

    2015-08-01

    The article presents a mathematical model to determine the flux of incinerated waste in terms of its calorific values. The model is applicable in waste incineration systems equipped with rotary kilns. It is based on the known and proven energy flux balances and equations that describe the specific losses of energy flux while considering the specificity of waste incineration systems. The model is universal as it can be used both for the analysis and testing of systems burning different types of waste (municipal, medical, animal, etc.) and for allowing the use of any kind of additional fuel. Types of waste incinerated and additional fuel are identified by a determination of their elemental composition. The computational model has been verified in three existing industrial-scale plants. Each system incinerated a different type of waste. Each waste type was selected in terms of a different calorific value. This allowed the full verification of the model. Therefore the model can be used to optimize the operation of waste incineration system both at the design stage and during its lifetime.

  5. Microscale investigation of arsenic distribution and species in cement product from cement kiln coprocessing wastes.

    PubMed

    Yang, Yufei; Xue, Jingchuan; Huang, Qifei

    2013-01-01

    To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As) in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA) and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O) were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H) was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF) of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V) and mainly existed as Mg3(AsO4)2, Ca3(AsO4)2, and Na2HAsO4.

  6. Thermal treatment of the fly ash from municipal solid waste incinerator with rotary kiln.

    PubMed

    Wey, Ming-Yen; Liu, Kuang-Yu; Tsai, Tsung-Hsun; Chou, Jing-Tong

    2006-09-21

    Reuse of the fly ash from the municipal solid waste incinerator (MSWI) is a policy of Taiwan EPA. However, the fly ash is often classified as a hazardous waste and cannot be reused directly because the concentrations of heavy metals exceed the TCLP regulations. The main objective of this study is to investigate the continuous sintering behavior of fly ash with a rotary kiln and seek a solution to reduce the concentrations of heavy metal to an acceptable value. The partitions of the heavy metals in the process are also considered. The results of TCLP showed that among the metals of Cr, Cd, Cu and Pb, only the concentrations of Pb in raw fly ash exceeded the regulation. At sintering temperatures of 700, 800 and 900 degrees C, the concentration of Pb decreased in sintering products, however, the concentration of Pb still exceeded the limitation at 700 and 800 degrees C. Additionally, the water-washing was used to pre-treat the fly ash before sintering process. The washing treatment effectively reduced the leaching concentrations of Pb to agree the regulations. Therefore, water-washing followed by a sintering treatment is an available process for detoxifying the fly ash of MSWI.

  7. Real-time O2 measurement in a cement kiln with a TDLAS analyzer

    NASA Astrophysics Data System (ADS)

    Gao, Yanwei; Zhang, Yujun; Chen, Dong; He, Ying; You, Ku; Chen, Chen; Liu, Wenqing

    2016-10-01

    Cement kilns are the main source of atmospheric pollutants, and will consume large amounts of fuel. In order to reduce the emissions of gas pollutants and saving fuel, the combustion process inside the furnace is needed to monitor in real time. Oxygen is the main combustion-supporting gas, monitoring the oxygen concentration inside the furnace can be implemented to combustion control and optimize combustion efficiency. We developed a TDLAS analyzer for real-time oxygen concentration measurement to achieve fuel saving and gas pollutant emission reduction. We realized temperature correction algorithm using the relationship between high-temperature oxygen line strength and measurement temperature, improving the measurement accuracy of the oxygen concentration at different temperatures. We tested the analyzer and the test results show that detection limit was 0.1%, analyzer can be achieved accurate measurement of oxygen concentration, the measured oxygen concentration was 5-8%. Results were true and reliable indicated that the oxygen measuring system can be developed to achieve long-term stability operation in high-temperature environments oxygen concentration measurement.

  8. FTIR spectroscopic features of γ-ray influence on new cement kiln dust based glasses

    NASA Astrophysics Data System (ADS)

    Saddeek, Yasser B.; Mohamed, Gehan Y.; Shokry Hassan, H.; Mostafa, A. M. A.; Abd elfadeel, G.

    2015-08-01

    A harmful environmental problem such as cement kiln dust (CKD) was considered as a source of CaO and SiO2, which are useful oxides for the glass industry. So, Na2O, B2O3, Bi2O3, PbO and CKD were used to fabricate new borate based glasses. The structure of the prepared glasses was studied by FTIR before and after gamma irradiation at doses up to 120 kGy. Analysis of FTIR before irradiation revealed that CKD split the characteristic broad band of the vibrations of BO3 structural units into two bands and created two effective ranges of concentrations which were confirmed by N4 calculations. After gamma irradiation, the intensity of the FTIR bands decreased and the structure of glass was weakened when 0 ≤ CKD ≤ 23.5 mol% as a result of energy transferred by gamma rays. Increasing CKD beyond this limit created bridging oxygens, more covalent bonds and interlinked the structural groups of the glass network which may resist the irradiation effects. The glass containing 32 mol% of CKD showed higher resistance for radiation effects which was attributed to its strong covalent bonds and to [BiO6] and [PbO6] structural units.

  9. Mineral carbonation for carbon sequestration in cement kiln dust from waste piles.

    PubMed

    Huntzinger, Deborah N; Gierke, John S; Sutter, Lawrence L; Kawatra, S Komar; Eisele, Timothy C

    2009-08-30

    Alkaline earth metals, such as calcium and magnesium oxides, readily react with carbon dioxide (CO(2)) to produce stable carbonate minerals. Carbon sequestration through the formation of carbonate minerals is a potential means to reduce CO(2) emissions. Calcium-rich, industrial solid wastes and residues provide a potential source of highly reactive oxides, without the need for pre-processing. This paper presents the first study examining the feasibility of carbon sequestration in cement kiln dust (CKD), a byproduct generated during the manufacturing of cement. A series of column experiments were conducted on segments of intact core taken from landfilled CKD. Based on stoichiometry and measured consumption of CO(2) during the experiments, degrees of carbonation greater than 70% of the material's potential theoretical extent were achieved under ambient temperature and pressure conditions. The overall extent of carbonation/sequestration was greater in columns with lower water contents. The major sequestration product appears to be calcite; however, more detailed material characterization is need on pre- and post-carbonated samples to better elucidate carbonation pathways and products.

  10. Learning, Labour and Employability

    ERIC Educational Resources Information Center

    Ball, Malcolm J.

    2009-01-01

    Public policy in the UK has adopted employability to define the relationship of globalisation, work and learning. This article claims that employability serves the interests of capital. It helps capital to exercise its domination/hegemony over labour and employs a redefined vision of learning as its principal vehicle. Employability is a term that…

  11. Becoming Self-Employed.

    ERIC Educational Resources Information Center

    Lee, Grant; Cochran, Larry

    1997-01-01

    Explored how persons become self-employed. In critical incident interviews with five self-employed persons the critical events that assisted or hindered progress toward self-employment were listed in chronological order. In general, becoming self-employed involved establishing conditions of action that enhanced a sense of agency, thus enabling…

  12. Effects of alternate fuels report No. 8: analysis of degradiation of magnesia-based refractory bricks from a residual oil-fired rotary cement kiln

    SciTech Connect

    Federer, J.I.; Tennery, V.J.

    1980-05-01

    Residual oil was used as an alternate fuel to natural gas to supply heat in a rotary cement kiln. Principal impurities in the residual oil were Ca, Fe, Mg, Na, Ni, P.S. and V. the kiln operators were concerned about the effects of these oil impurities on observed degradation of the magnesia-based bricks used as a liner in the burning zone of the kiln. Two degraded bricks, which had been in service for six to nine months, were analyzed to determine the role of fuel impurities on the observed degradation. The maximum hot-face temperature of the refractory during service was about 1500/sup 0/C. One brick had decreased in thickness about 45%, the about 15%. Various analytical measurements on these samples failed to reveal the presence of fuel impurities at or near the hot face of the bricks, and therefore it is concluded that the relatively short service life of these refractories was not due to use of residual oil as the fuel in the kiln. The observed degradation, therefore, was attributed to other reactions and to thermal mechanical conditions in the kiln, which inevitably resulted in extensive erosion of the bricks.

  13. Fluidized bed charcoal particle production system

    SciTech Connect

    Sowards, N.K.

    1985-04-09

    A fluidized bed charcoal particle production system, including apparatus and method, wherein pieces of combustible waste, such as sawdust, fragments of wood, etc., are continuously disposed within a fluidized bed of a pyrolytic vessel. Preferably, the fluidized bed is caused to reach operating temperatures by use of an external pre-heater. The fluidized bed is situated above an air delivery system at the bottom of the vessel, which supports pyrolysis within the fluidized bed. Charcoal particles are thus formed within the bed from the combustible waste and are lifted from the bed and placed in suspension above the bed by forced air passing upwardly through the bed. The suspended charcoal particles and the gaseous medium in which the particles are suspended are displaced from the vessel into a cyclone mechanism where the charcoal particles are separated. The separated charcoal particles are quenched with water to terminate all further charcoal oxidation. The remaining off-gas is burned and, preferably, the heat therefrom used to generate steam, kiln dry lumber, etc. Preferably, the bed material is continuously recirculated and purified by removing tramp material.

  14. Stabilization/solidification of selenium-impacted soils using Portland cement and cement kiln dust.

    PubMed

    Moon, Deok Hyun; Grubb, Dennis G; Reilly, Trevor L

    2009-09-15

    Stabilization/solidification (S/S) processes were utilized to immobilize selenium (Se) as selenite (SeO(3)(2-)) and selenate (SeO(4)(2-)). Artificially contaminated soils were prepared by individually spiking kaolinite, montmorillonite and dredged material (DM; an organic silt) with 1000 mg/kg of each selenium compound. After mellowing for 7 days, the Se-impacted soils were each stabilized with 5, 10 and 15% Type I/II Portland cement (P) and cement kiln dust (C) and then were cured for 7 and 28 days. The toxicity characteristic leaching procedure (TCLP) was used to evaluate the effectiveness of the S/S treatments. At 28 days curing, P doses of 10 and 15% produced five out of six TCLP-Se(IV) concentrations below 10mg/L, whereas only the 15% C in DM had a TCLP-Se(IV) concentration <10mg/L. Several treatments satisfied the USEPA TCLP best demonstrated available technology (BDAT) limits (5.7 mg/L) for selenium at pozzolan doses up to 10 times less than the treatments that established the BDAT. Neither pozzolan was capable of reducing the TCLP-Se(VI) concentrations below 25mg/L. Se-soil-cement slurries aged for 30 days enabled the identification of Se precipitates by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX). XRD and SEM-EDX analyses of the Se(IV)- and Se(VI)-soil-cement slurries revealed that the key selenium bearing phases for all three soil-cement slurries were calcium selenite hydrate (CaSeO(3).H(2)O) and selenate substituted ettringite (Ca(6)Al(2)(SeO(4))(3)(OH)(12).26H(2)O), respectively.

  15. Phytoextraction of chloride from a cement kiln dust (CKD) contaminated landfill with Phragmites australis.

    PubMed

    McSorley, Kaitlin; Rutter, Allison; Cumming, Robert; Zeeb, Barbara A

    2016-05-01

    Cement kiln dust (CKD) is a globally produced by-product from cement manufacturing that is stockpiled or landfilled. Elevated concentrations of chloride pose toxic threats to plants and aquatic communities, as the anion is highly mobile in water and can leach into surrounding water sources. Re-vegetation and in situ phytoextraction of chloride from a CKD landfill in Bath, ON, Canada, was investigated with the resident invasive species Phragmites australis (haplotype M). Existing stands of P. australis were transplanted from the perimeter of the site into the highest areas of contamination (5.9×10(3)μg/g). Accumulation in the shoots of P. australis was quantified over one growing season by collecting samples from the site on a bi-weekly basis and analyzing for chloride. Concentrations decreased significantly from early May (24±2.2×10(3)μg/g) until mid-June (15±2.5×10(3)μg/g), and then remained stable from June to August. Shoot chloride accumulation was not significantly affected by water level fluctuations at the site, however elevated potassium concentrations in the soil may have contributed to uptake. Based on shoot chloride accumulation and total biomass, it was determined that phytoextraction from the CKD landfill can remove 65±4kg/km(2) of chloride per season. Based on this extraction rate, removal of chloride present in the highly contaminated top 10cm of soil can be achieved in 3-9years. This is the first study to apply phytotechnologies at a CKD landfill, and to successfully demonstrate in situ phytoextraction of chloride.

  16. Soil stratigraphy of charcoal kiln remains (CKR) in the Litchfield Hills, CT, USA

    NASA Astrophysics Data System (ADS)

    Raab, Thomas; Hirsch, Florian; Ouimet, Will; Dethier, David

    2016-04-01

    Charcoal kiln relicts (CKRs) are small anthropogenic landforms that are often found in historic mining areas. CKRs have not been a big research topic yet but mainly were studied as by-products of archaeological excavations. In the last years newly available and very accurate Digital Elevation Models (DEMs) based on high-resolution Airborne Laser Scanning (ALS) data have been used to identify these archaeological remains. In addition, findings of several thousands CKRs in the North German Lowland have increased the awareness that historical charcoal production may significantly contribute to Late Holocene landscape change. Besides the archaeological aspect of CKRs, potential impacts of charcoal burning on the ecology of modern soil landscapes and ecosystem processes must be considered. A relatively high density of CKRs is found in the Litchfield Hills nearby the town of West Cornwall, Litchfield County, CT, USA. The CKRs are especially well preserved on slopes of the tributary valleys of the Housatonic River and form little, circular ramparts with diameters normally less than ten meters. First, rough field surveys in Litchfield County in spring 2015 have suggested differences between soils inside and outside the CKR. Soils on the CKR seem to have relatively deep humus-rich and charcoal containing topsoils whereas the topsoils outside the CKR appear typically thinner and less rich in humus. More thorough investigations have been started in autumn 2015 to prove the hypothesis that properties, distribution and development of soils are controlled by archaeological remains of historical charcoal burning. We present preliminary results from our field studies conducted in October 2015. The stratigraphy and the extent of the 26 CKRs were studied using a sedimentological-pedological approach by coring and trenching. Our results indicate that in Litchfield County the CKRs were used twice and in quick succession. Before the second reuse, the rim of the platform was stabilized

  17. Youth Employment. Policy Statement.

    ERIC Educational Resources Information Center

    National Collaboration for Youth, Washington, DC.

    This paper presents the policy statement on youth employment from the National Collaboration for Youth (NCY). An introduction briefly explains the role of the NCY with regard to youth employment and describes the types of programs and services supported by NCY. A section on background provides statistics on teenagers and employment from the Bureau…

  18. The New Employment Contract?

    ERIC Educational Resources Information Center

    Levine, David I.

    2002-01-01

    In the classic employment contract, especially at large companies, wages were not strongly responsive to the labor market. Instead, individual companies had distinctive company wage levels and patterns. An exhaustive study of employers and employees in the United States and Japan examined whether the "old employment contract" has been…

  19. Employers Roundtable: Employer Supported Child Care.

    ERIC Educational Resources Information Center

    Delaware Valley Child Care Council, Philadelphia, PA.

    This booklet outlines a number of options available to employers to enable them to better cope with child care issues that they and their employees face. Major options include: (1) flexible work policies, such as flexible scheduling, alternate work places, shorter work weeks, and the consolidating of sick leave, holidays, and vacation time into…

  20. Trace gas and particle emissions from domestic and industrial biofuel use and garbage burning in central Mexico

    NASA Astrophysics Data System (ADS)

    Christian, T. J.; Yokelson, R. J.; Cárdenas, B.; Molina, L. T.; Engling, G.; Hsu, S.-C.

    2009-04-01

    In central Mexico during the spring of 2007 we measured the initial emissions of 12 gases and the aerosol speciation for elemental and organic carbon (EC, OC), anhydrosugars, Cl-, NO3-, and 20 metals from 10 cooking fires, four garbage fires, three brick making kilns, three charcoal making kilns, and two crop residue fires. Biofuel use has been estimated at over 2600 Tg/y. With several simple case studies we show that cooking fires can be a major, or the major, source of several gases and fine particles in developing countries. Insulated cook stoves with chimneys were earlier shown to reduce indoor air pollution and the fuel use per cooking task. We confirm that they also reduce the emissions of VOC pollutants per mass of fuel burned by about half. We did not detect HCN emissions from cooking fires in Mexico or Africa. Thus, if regional source attribution is based on HCN emissions typical for other types of biomass burning (BB), then biofuel use and total BB will be underestimated in much of the developing world. This is also significant because cooking fires are not detected from space. We estimate that 2000 Tg/y of garbage are generated and about half may be burned, making this a commonly overlooked major global source of emissions. We estimate a fine particle emission factor (EFPM2.5 for garbage burning of ~10±5 g/kg, which is in reasonable agreement with very limited previous work. We observe large HCl emission factors in the range 2-10 g/kg. Consideration of the Cl content of the global waste stream suggests that garbage burning may generate as much as 6-9 Tg/yr of HCl, which would make it a major source of this compound. HCl generated by garbage burning in dry environments may have a relatively greater atmospheric impact than HCl generated in humid areas. Garbage burning PM2.5 was found to contain levoglucosan and K in concentrations similar to those for biomass burning, so it could be a source of interference in some areas when using these tracers to

  1. Adhesive particle shielding

    DOEpatents

    Klebanoff, Leonard Elliott; Rader, Daniel John; Walton, Christopher; Folta, James

    2009-01-06

    An efficient device for capturing fast moving particles has an adhesive particle shield that includes (i) a mounting panel and (ii) a film that is attached to the mounting panel wherein the outer surface of the film has an adhesive coating disposed thereon to capture particles contacting the outer surface. The shield can be employed to maintain a substantially particle free environment such as in photolithographic systems having critical surfaces, such as wafers, masks, and optics and in the tools used to make these components, that are sensitive to particle contamination. The shield can be portable to be positioned in hard-to-reach areas of a photolithography machine. The adhesive particle shield can incorporate cooling means to attract particles via the thermophoresis effect.

  2. Combustion of high-sulfur coal and anthracite wastes in a rotary kiln combustor with an advanced internal air distributor

    SciTech Connect

    Cobb, J.T. Jr. ); Ahn, Y.K. ); Angelo, J.F. )

    1990-01-01

    Fluid bed combustors have received extensive testing with both high-sulfur coal and anthracite wastes. Rotary kilns are effective and popular devices for waste combustion. The Angelo Rotary Furnace{trademark} has been developed to improve the operation of rotary pyrolyzer/combustor systems through enhanced air distribution, which in this process is defined as staged, swirled combustion air injection. Fourteen of these new furnaces have been installed worldwide. Two units in Thailand, designed for rice hull feed with occasional lignite feed, have been recently started up. An older unit in Pennsylvania is being upgraded with a new, more advanced air distribution system for a series of tests this fall in which inexpensive high-sulfur coal and anthracite wastes will be fired with limestone. The purposes of these tests are to determine the burning characteristics of these two fuels in this system, to discover the Ca/S ratios necessary for operation of a rotary kiln combusting these fuels, and to observe the gas-borne emissions from the furnace. An extensive preliminary design study will be performed on a commercial installation for combustion of anthracite wastes. 14 refs., 5 figs., 1 tab.

  3. Removal of lead by using Raschig rings manufactured with mixture of cement kiln dust, zeolite and bentonite.

    PubMed

    Salem, A; Afshin, H; Behsaz, H

    2012-07-15

    The present investigation is a follow-up of study on manufacturing Raschig ring for removal of lead from aqueous solution. The mixtures were formulated using cement kiln dust, zeolite, and bentonite, normally used as natural adsorbents in the industrial scale, according to mixture design algorithm and response surface method. The pastes were prepared by addition of 28.0wt.% de-ionized water, containing 0.1wt.% carboxymethyl cellulose, with mixed powders. The adsorbents were fabricated by extrusion of the pastes in Raschig ring form and calcination at 500°C after drying in oven. The effects of starting materials on the mechanical behavior of rings were studied from view point of mixture design algorithm to optimize the adsorbent composition. This method demonstrated to yield valuable information on the effects of used materials on mechanical characteristics. The study concluded that the strength, reliability and sorption capacity of ring can be simultaneously optimized by the addition of 47.5wt.% cement kiln dust, 32.5wt.% zeolite, and 20.0wt.% bentonite. In the next part of work, the sorption kinetics was investigated. The kinetic study indicated that the modified model can successfully correlate the sorption data. The equilibrium result showed the possibility of lead immobilization by fabricated rings.

  4. Effect of fuel and kiln type on the polycyclic aromatic hydrocarbon (PAH) levels in smoked shrimp, a Beninese food condiment.

    PubMed

    Kpoclou, Euloge Yénoukounmè; Anihouvi, Victor Bienvenu; Azokpota, Paulin; Soumanou, Mohamed Mansourou; Douny, Caroline; Brose, François; Hounhouigan, Djidjoho Joseph; Scippo, Marie-Louise

    2014-01-01

    Smoked shrimp is a food condiment widely used in Beninese local cooking practices. A previous study revealed that this product is highly contaminated with polycyclic aromatic hydrocarbons (PAH). The present study explored possibilities to reduce PAH levels in shrimp smoked using cottage industry smoking techniques with barrel and chorkor kilns, by replacing wood by charcoal from Acacia auriculiformis and Mangifera indica, as fuels. Results showed that only shrimp smoked using acacia charcoal in a chorkor kiln had PAH levels (benzo[a]pyrene = 5 µg kg(-1) and sum of benzo[a]pyrene, chrysene, benzo[a]anthracene and benzo[b]fluoranthene = 28 µg kg(-1)) in accordance with a European standard of 5 and 30 µg kg(-1), respectively, and suitable physicochemical characteristics for good storage (moisture content = 11.9% ± 1.5%; water activity = 0.46 ± 0.03). However, further investigations still needs to be done to reduce the duration of product contact with combustion gasses in order to reduce the PAH content of smoked shrimp to safer levels, largely below standards.

  5. Employment specialist competencies as predictors of employment outcomes.

    PubMed

    Taylor, Amanda C; Bond, Gary R

    2014-01-01

    Employment specialist competencies were examined as predictors of employment outcomes for consumers with serious mental illness participating in supported employment. Self-report and supervisor-rated performance measures from 57 employment specialists were correlated with three consumer employment outcomes (i.e., competitive employment rate, 90-day employment rate, and dropout rate). Employment specialists varied from 0 to 80 % in the competitive employment rates for their caseloads. Supervisor ratings of job performance and employment specialist efficacy, percentage of time in the community, and frequency of contacts with consumers were associated with employment outcomes. Employment specialist self-report measures were unrelated to employment outcomes. Surprisingly, employment specialists with larger caseload sizes had higher employment rates. Employment specialists vary widely in their effectiveness. Behavioral measures and supervisory ratings of employment specialists were most predictive of employment outcomes. Direct observation of employment specialist job performance appears to be the most promising method for identifying competencies predictive of employment outcome.

  6. Former charcoal kiln sites where forest was cleared for cultivation: a case study of old biochar in cropland

    NASA Astrophysics Data System (ADS)

    Hardy, Brieuc; Dufey, Joseph E.; Cornelis, Jean-Thomas

    2014-05-01

    The use of biochar as a soil amendment is being increasingly investigated as a win-win solution for mitigating the anthropic CO2 emissions and improving soil fertility. However, data on the long term impact of chars on soil properties are scarce, although they are crucial for better understanding the implications of large scale application of highly persistent biochars to soil. In Wallonia (Belgium), old charcoal kilns are found in most of the area that was forested in the late 18th century. Since then, a non-negligible part of the forest has been cleared for cultivation. Today, old charcoal-making platforms can be seen on bare soils as circular or elliptic black spots due to charcoal enrichment. In order to assess the long-term (>200 years) effects of biochar on soil chemical properties, seventeen kiln sites were chosen in several cropland areas of Wallonia on loessic luvisols (14) and loamy cambisols (3). Composite samples were taken in the ploughing layer (0 - 25 cm) and the underlying horizon (35 - 50 cm) in and out the kiln sites. The pH, total carbon (C) and nitrogen (N) contents, oxidizable carbon (CW&B), available phosphorus (Pav), cation exchange capacity at pH 7 (CEC), exchangeable cations content (Ca++, Mg++, K+, Na+) and loss on ignition at 550°C (LI550) were measured. In order to assess the impact of cultivation on charcoal aging, we also sampled four kiln sites on loessic luvisols under forest. Here, we show that charcoal, diluted laterally by successive tillage, acts as a carbon surplus in the topsoil layer of the black spots. The charcoal-enriched horizon is characterized by higher CEC, C/N and C/LI550 ratio compared to the reference soil. Cultivation of former forest soils accelerates charcoal aging, likely due to a combined effect of mechanical (tillage splits charcoal fragments in smaller pieces and increases soil aeration) and biological actions (promoted by improved trophic conditions due to application of amendments and fertilizers over many

  7. [Chemical composition analysis of bluish-white porcelain unearthed from Fanchang kiln, Anhui province by wave disperse X-ray fluorescence].

    PubMed

    Yang, Yu-zhang; Zhang, Ju-zhong; Zan, Yi

    2010-08-01

    Fanchang kiln was the earliest Chinese bluish-white porcelain kiln which first fired this special porcelain class as early as in Five Dynasties (AD 907-960). However, this important kiln declined rapidly in the middle North Song dynasty (AD 1023-1085). As to the decline reason, it is still not clearly identified till now. In order to find the truth, wavelength-dispersive X-ray fluorescence (WDXRF) was used to determine the elemental abundance patterns of its porcelain bodies in Five Dynasties, the early North Song dynasty and the middle North Song dynasty. The analytical results indicate that the chemical compositions of major, minor and trace elements in porcelain bodies changed greatly in the middle North Song dynasty. Combined with the results of INAA and glaze study, this change in elemental composition should be caused by the change in porcelain raw materials or body-making crafts. Meanwhile, it was just this change that led to the quality decline of raw material and rapid collapse of Fan-chang kiln in the middle North Song dynasty shortly after its establishment.

  8. Field pilot study on emissions, formations and distributions of PCDD/Fs from cement kiln co-processing fly ash from municipal solid waste incinerations.

    PubMed

    Liu, Guorui; Zhan, Jiayu; Zheng, Minghui; Li, Li; Li, Chunping; Jiang, Xiaoxu; Wang, Mei; Zhao, Yuyang; Jin, Rong

    2015-12-15

    A pilot study was performed to evaluate formation, distribution and emission of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from cement kilns that co-process fly ash from municipal solid waste incineration (MSWI). Stack gas and particulate samples from multiple stages in the process were collected and analyzed for PCDD/Fs. Stack emissions of PCDD/Fs were below the European Union limit for cement kilns (0.1 ng TEQ m(-3)). PCDD/F concentrations in particulates from the cyclone preheater outlet, suspension preheater boiler, humidifier tower, and back-end bag filter were much higher than in other samples, which suggests that these areas are the major sites of PCDD/F formation. Comparison of PCDD/F homolog and congener profiles from different stages suggested that tetra- and penta-chlorinated furans were mainly formed during cement kiln co-processing of MSWI fly ash. Three lower chlorinated furan congeners, including 2,3,7,8-tetrachlorodibenzofuran, 1,2,3,7,8-pentachlorodibenzo-p-dioxin and 2,3,4,7,8-pentachlorodibenzofuran, were identified as dominant contributors to the toxic equivalents (TEQ) of the PCDD/Fs. The concentration of PCDD/Fs in particulates was correlated with chloride content, which is consistent with its positive effect on PCDD/F formation. This could be mitigated by pretreating the feedstock to remove chloride and metals. Mass balance indicated that cement kilns eliminated about 94% of the PCDD/F TEQ input from the feedstock.

  9. THE FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A SINGLE-STAGE IONIZING WET SCRUBBER - VOLUME II: APPENDICES

    EPA Science Inventory

    A series of pilot-scale incineration tests was performed at EPA's Incineration Research Facility (IRF) in Jefferson, Arkansas, to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with an ionizing wet scrubber (IWS) for particulate and acid gas control. ...

  10. THE FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A VENTURI/PACKED COLUMN SCRUBBER - VOLUME I: TECHNICAL RESULTS

    EPA Science Inventory

    A five week series of pilot-scale incineration tests, using a synthetic waste feed, was performed at the Environmental Protection Agency's Incineration Research Facility to evaluate the fate of trace metals fed to a rotary kiln incinerator. Eight tests studied the fate of five ha...

  11. FATE OF TRACE METALS IN A ROTARY KILN INCINERATOR WITH A SINGLE-STAGE IONIZING WET SCRUBBER. VOLUME 1. TECHNICAL RESULTS.

    EPA Science Inventory

    A series of pilot-scale incineration tests was performed at EPA's Incineration Research Facility (IRF) in Jefferson, Arkansas, to evaluate the fate of trace metals fed to a rotary kiln incinerator equipped with an ionizing wet scrubber (IWS) for particulate and acid gas control. ...

  12. SUPERFUND TREATABILITY CLEARINGHOUSE: FULL SCALE ROTARY KILN INCINERATOR FIELD TRIAL: PHASE I, VERIFICATION TRIAL BURN ON DIOXIN/HERBICIDE ORANGE CONTAMINATED SOIL

    EPA Science Inventory

    This treatability study reports on the results of one of a series of field trials using various remedial action technologies that may be capable of restoring Herbicide Orange (HO)XDioxin contaminated sites. A full-scale field trial using a rotary kiln incinerator capable of pro...

  13. Field study and theoretical evidence for the profiles and underlying mechanisms of PCDD/F formation in cement kilns co-incinerating municipal solid waste and sewage sludge.

    PubMed

    Zhao, Yuyang; Zhan, Jiayu; Liu, Guorui; Ren, Zhiyuan; Zheng, Minghui; Jin, Rong; Yang, Lili; Wang, Mei; Jiang, Xiaoxu; Zhang, Xian

    2017-03-01

    A field study and theoretical calculations on the profile and formation mechanism of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) from two cement kilns co-incinerating municipal solid waste and sewage sludge were performed, and the PCDFs were mainly focused. The back-end areas of the cement kilns were identified to be the major sites of PCDD/F formation according to their distributions in particulate samples from different process stages. The proportions of tetra- to hexa-chlorinated dibenzofurans (∑Cl4-6CDFs) at the kiln back-end areas were in the range of 50-80% of the total PCDD/Fs in mass concentrations and 62-87% in toxic equivalent concentrations. These results indicated that ∑Cl4-6CDFs are the dominant homologs that should be the focus for reducing PCDD/F emissions in cement kilns that co-incinerate municipal solid waste and sewage sludge. It is speculated that the low contents of oxygen and copper compounds, as well as the alkaline conditions, may contribute to the dominance of ∑Cl4-6CDFs in the PCDD/Fs formed. Chlorination was assumed to be the mechanism of formation of PCDFs. The results from model predictions and thermodynamic calculations used to test this assumption were consistent with the PCDF profiles observed from the field study.

  14. Youth-Education-Employment.

    ERIC Educational Resources Information Center

    Wirtz, Willard; And Others

    The document presents the proceedings of an international symposium analyzing the relationship among youth, education, and employment, with emphasis on youth employment trends and the need to find solutions for unemployment problems. The objectives are to evaluate the existing relationship in the light of changing values and expectations of young…

  15. Addressing Employer Services.

    ERIC Educational Resources Information Center

    Perspective: Essays and Reviews of Issues in Employment Security and Employment and Training Programs, 1986

    1986-01-01

    This volume of an annual journal contains 21 articles focusing on the many services that state Employment Security (ES) agencies are providing to improve outreach to employers who pay for the programs through the dedicated revenues of the Federal Unemployment Tax Act and state benefit taxes and to improve their own staff ability to deliver…

  16. Employment and Training Programs.

    ERIC Educational Resources Information Center

    Minnesota State Office of the Legislative Auditor, St. Paul. Program Evaluation Div.

    This report examines the effectiveness of employment and training programs in Minnesota and discusses the impact of the 1985 Jobs Bill state legislation. Chapter 1 provides an introduction to Minnesota's programs and to studies of employment and training programs conducted nationwide. Chapter 2 studies the use of Job Training Partnership Act funds…

  17. Maine's Employability Skills Program

    ERIC Educational Resources Information Center

    McMahon, John M.; Wolffe, Karen E.; Wolfe, Judy; Brooker, Carrie

    2013-01-01

    This Practice Report describes the development and implementation of the "Maine Employability Skills Program," a model employment program developed by the Maine Division for the Blind and Visually Impaired (DBVI). The program was designed to support the efforts of the chronically unemployed or underemployed. These consumers were either…

  18. Employment and Unemployment.

    ERIC Educational Resources Information Center

    Simler, N. J.

    Three sections of information are presented in this report on employment and unemployment. Section 1 discusses how the concepts of employment, unemployment, and the labor force are defined and measured. Included in the discussion is an explanation of the current population survey. Section 2 examines the principal trends and cyclical movements of…

  19. Employment Policy and Territories.

    ERIC Educational Resources Information Center

    Berthet, Thierry; Cuntigh, Philippe; Guitton, Christophe

    2002-01-01

    France's employment policy has historically been governed by a strategy of interventions aimed at specific categories of individuals, including victims of industrial restructuring, entry workers, the long-term unemployed, and the disabled. Since the 1980s, France has had the following main lines of employment policy: (1) assistance to victims of…

  20. Energy and employment

    SciTech Connect

    Nordlund, W.J.; Robson, R.T.

    1980-01-01

    The relationship of energy and employment is an essential ingredient of the current energy-policy debate. Energy, in its various forms, is an almost universal input to the production and consumption of goods and services in modern society, yet little attention is paid to its employment impacts. Far too little attention is being paid to the impact that changes in the sources, uses, and prices of energy will have on the level, location, and structure of employment in the U.S. economy. Unless their consequences are foreseen, energy solutions may have profound and sometimes devastating effects upon regions, industries, and jobs. This study addresses eight areas of this relationship: labor supply and demand in the energy sector; socio-economic impacts of energy development; coal, electricity, and employment; energy as a factor in the production/consumption process; alternative technologies and employment; developing an energy/employment modeling capability; research priorities; and policy recommendations related to energy/employment relationships. 40 references, 7 figures, 22 tables.

  1. Farm Employment Trends

    ERIC Educational Resources Information Center

    Rural Manpower Developments, 1973

    1973-01-01

    The heavy spring rains of 1973 led to delays and reduced acreage in planting, resulting in a sharp decline in vegetable and cotton employment. Seasonal farmworker job levels are reported by state and activity. (MS)

  2. Placement: The Employer's View.

    ERIC Educational Resources Information Center

    Teff, Donald R.

    1979-01-01

    A bank vice president reviews three barriers to the employment of handicapped persons: misunderstanding and lack of knowledge concerning the handicapped, the traditional lag between recognition of a problem and its solution, and apathy and disinterest. (CL)

  3. High vacuum indirectly-heated rotary kiln for the removal and recovery of mercury from air pollution control scrubber waste

    SciTech Connect

    Hawk, G.G.; Aulbaugh, R.A.

    1998-12-31

    SepraDyne corporation (Denton, TX, US) has conducted pilot-scale treatability studies of dewatered acid plant blowdown sludge generated by a copper smelter using its recently patented high temperature and high vacuum indirectly-heated rotary retort technology. This unique rotary kiln is capable of operating at internal temperatures up to 850 C with an internal pressure of 50 torr and eliminates the use of sweep gas to transport volatile substances out of the retort. By removing non-condensables such as oxygen and nitrogen at relatively low temperatures and coupling the process with a temperature ramp-up program and low temperature condensation, virtually all of the retort off-gases produced during processing can be condensed for recovery. The combination of rotation, heat and vacuum produce the ideal environment for the rapid volatilization of virtually all organic compounds, water and low-to-moderate boiling point metals such as arsenic, cadmium and mercury.

  4. Recovery of aluminum oxide by the Ames lime-soda sinter process: scale-up using a rotary kiln

    SciTech Connect

    Murtha, M.J.; Burnet, G.; Harnby, N.

    1985-01-01

    The Ames Lime-Soda Sinter Process provides a means for recovering aluminum oxide from power plant fly ash while producing a residue that can be used in the manufacture of sulfate resistant (Type V) portland cement. The process has been fully researched and its feasibility is now being demonstrated through pilot plant scale investigation. This paper reports results of the pelletized feed preparation by agglomeration in a rotary pan granulator, continuous feed sintering in an electrically heated rotary kiln, and product recovery from the clinker by aqueous extraction, desilication of the filtrate, and precipitation of a hydrated aluminum oxide. Results from earlier bench-scale research have been found to apply consistently to the pilot plant scale work.

  5. Effect of incorporating hydrothermal, kilned and defatted oats on antioxidant and chapatti making properties of wheat flour.

    PubMed

    Gujral, Hardeep Singh; Sharma, Paras; Gill, Balmeet Singh; Kaur, Sumandeep

    2013-06-01

    Oats were subjected to treatments like defatting, hydrothermal cooking and kilning, milled into flour and then the control and treated flours were incorporated into wheat flour at 25% and 50% levels and chapatti making behaviour and antioxidant properties were studied. The treatments significantly affected the antioxidant properties of oats. Incorporating oat flours to wheat increased total phenolic content but lowered the antioxidant activity however both were decreased significantly upon baking. The reducing power of the oat blended flour was higher than the wheat flours and ranged from 8.0 to 15.5 μmol AAE/g and was further increased upon baking. The metal chelating activity of flour blends varied from 62.0% to 73.8% and further increased upon baking. After baking the total flavonoid content was lowered and ranged from 308 to 389 μg CE/g. The non-enzymatic browning index significantly increased up to 27.6% upon baking.

  6. Determination of cross-grain properties of clearwood samples under kiln-drying conditions at temperature up to 140 C

    SciTech Connect

    Keep, L.B.; Keey, R.B.

    2000-07-01

    Small specimens of Pinus radiata have been tested to determine the creep strain that occurs during the kiln drying of boards. The samples have been tested over a range of temperatures from 20 C to 140 C. The samples, measuring 150 x 50 x 5 mm, were conditioned at various relative humidities in a pilot-plant kiln, in which the experiments at constant moisture content (MC) in the range of 5--20% MC were undertaken to eliminate mechano-sorptive strains. To determine the creep strain, the samples were brought to their equilibrium moisture content (EMC), then mechanically loaded under tension in the direction perpendicular to the grain. The strain was measured using small linear position sensors (LPS) which detect any elongation or shrinkage in the sample. The instantaneous compliance was measured within 60 sec of the application of the load (stress). The subsequent creep was monitored by the continued logging of strain data from the LPS units. The results of these experiments are consistent with previous studies of Wu and Milota (1995) on Douglas-fir (Pseudotsuga Menziesii). An increase in temperature or moisture content causes a rise in the creep strain while the sample is under tension. Values for the instantaneous compliance range from 1.7 x 10{sup {minus}3} to 1.28 x 10{sup {minus}2} M/Pa at temperatures between 20 C and 140 C and moisture content in the range of 5--20%. The rates of change of the creep strains are in the order of magnitude 10{sup {minus}7} to 10{sup {minus}8 s{sup {minus}1}} for these temperatures and moisture contents. The experimental data have been fitted to the constitutive equations of Wu and Milota (1996) for Douglas-fir to give material parameters for the instantaneous and creep strain components for Pinus radiata.

  7. Evaluation of near-infrared tunable diode lasers for detection of transient emissions from a rotary kiln.

    SciTech Connect

    Shaddix, Christopher R.; Ottesen, David K.; Allendorf, Sarah W.; Miller, C. Andy; Lemieux, Paul M.

    2003-12-01

    Near-infrared tunable diode lasers (TDLs) were evaluated for their suitability as fast-response combustion performance indicators during tests at the U.S. Environmental Protection Agency's pilot-scale Rotary Kiln Incinerator Simulator (RKIS) facility. Transient emissions (i.e., 'puffs') of various magnitudes and duration were generated by injecting a mixture of toluene and methylene chloride into the rotary kiln, through use of a computer-controlled liquid gun or by ram-loading containers of the waste surrogate adsorbed onto corncob. Two wavelength-modulated TDLs that span carbon monoxide (CO) and methane absorption lines at 1.57 and 1.65 pm, respectively, provided information on these species as well as total laser transmittance (an indicator of soot loading). Fiber-optic cables transmitted the laser light from the remotely situated TDLs to two line-of-sight measurement locations. In addition, the TDLs were used with a multi-pass optical cell to perform more sensitive extractive measurements. Over the optical pathlength available in this facility, in situ measurements of methane down to a concentration of {approx} 100 ppm were demonstrated during non-sooty conditions. CO could not be reliably quantified in situ, even at concentrations as high as 0.7%, due to the combination of weak absorption line strength and interfering water and carbon-dioxide hot-bands. The soot produced during the toluene/methylene chloride puffs typically attenuated over 90% of the TDL laser beam, preventing effective in situ TDL measurements during the puffs. In contrast, the extractive TDL measurements demonstrated good accuracy and sensitivity for both methane and CO under all reactor conditions. Furthermore, the in situ laser transmittance profiles during the puffs provided new insights into the composition of the puffs as a function of puff magnitude and residence time.

  8. Long-term sampling of dioxin-like substances from a clinker kiln stack using alternative fuels.

    PubMed

    Rivera-Austrui, J; Martinez, K; Marco-Almagro, L; Abalos, M; Abad, E

    2014-07-01

    The aim of this work is to characterize atmospheric emissions of polychlorinated dibenzo-p-dioxins (PCDDs)/polychlorinated dibenzofurans (PCDFs) and dioxin-like polychlorinated biphenyls (dl-PCBs) from a cement production plant where the existing clinker production line was completely replaced by a new state-of-the-art installation. The project started in April 2008 with the installation of a long-term sampling system in the stack of the clinker kiln that used petroleum coke as fuel; PCDD/PCDF and dl-PCB emissions were then evaluated for a two year period. To carry out the second part of the study, in 2010 the sampling system was moved to the new installation in which, apart from conventional fuel, recovered derived fuel (RDF) and WWTP sludge were used as alternative fuels. For both the old and new clinker kilns, PCDD/PCDF emission values were well below the limit established by the European Waste Incineration Directive 2000/76/CE (EWID) of 100 pg I-TEQ/Nm(3); values ranged from 0.43 to 2.02 and from 0.07 to 3.31 pg I-TEQ/Nm(3), respectively. dl-PCBs accounted for approximately 25% of the WHO-TEQ toxicity. These results prove that the installation is capable of reducing PCDD/PCDF and dl-PCB emissions when alternative fuels are integrated into the process. In the case of PCDDs/PCDFs, the major contributions to total TEQ were usually from 2,3,7,8-TCDD (owing to its relative abundance) and 2,3,4,7,8-PeCDF (due to its high I-TEF of 0.5); while for dl-PCBs, the major contribution was from PCB-126. The slight shift in the congener profile between the old and new installations was characterized and a regression model was proposed for dl-PCB emissions depending on the RDF flow rate in the clinker.

  9. Technology and employment

    SciTech Connect

    Cooper, M.H.

    1983-07-22

    The influence of technology on today's high unemployment picture is discussed. Employment in the high-technology sector is seen by some to be a panacea for workers who have lost their jobs due to irreversible structural causes. Some federal, regional, state, and local efforts being made to ease structural adjustment are included. 28 references, 2 figures, 3 tables.

  10. Employer Engagement in Education

    ERIC Educational Resources Information Center

    Mann, Anthony; Dawkins, James

    2014-01-01

    The subject of this paper is employer engagement in education as it supports the learning and progression of young people through activities including work experience, job shadowing, workplace visits, career talks, mock interviews, CV workshops, business mentoring, enterprise competitions and the provision of learning resources. Interest has grown…

  11. Westchester County Employers Survey.

    ERIC Educational Resources Information Center

    Lee, Marcia M.

    The Westchester County Employers Survey was done in May 2003 in order learn more about employee training needs, how they accomplished these needs, and how it would be possible for the Westchester Community College to fulfill these needs. Out of the 639 surveys sent, 145 were returned in a satisfactory format, which produces a 22.6% return rate.…

  12. Employer Satisfaction Survey.

    ERIC Educational Resources Information Center

    Broadbent, William A.

    A three-part, state-wide survey was conducted in Spring 1979, to determine employer satisfaction with the vocational programs offered at Hawaii's high schools and community colleges. Three populations were involved in the survey: (1) the personnel directors of 29 firms representing approximately 25% of the businesses in Hawaii with 250 or more…

  13. Employers, Families and Education.

    ERIC Educational Resources Information Center

    Partnership for Family Involvement in Education (ED), Washington, DC.

    Family involvement in education is good for business, critical to children's school achievement, and important in creating strong and vibrant communities. This report discusses the role of businesses and employers in helping partners and family members be more involved in children's learning. Throughout the report, programs at specific companies…

  14. Should Universities Promote Employability?

    ERIC Educational Resources Information Center

    McCowan, Tristan

    2015-01-01

    Employability is becoming increasingly central to the mission and functioning of universities, spurred on by national and supranational agencies, and the demands of marketisation. This article provides a response to the normative dimensions of the question, progressing through four stages: first, there is a brief consideration of the meaning and…

  15. The Employment Mismatch

    ERIC Educational Resources Information Center

    Fischer, Karin

    2013-01-01

    Employers value a four-year college degree, many of them more than ever. Yet half of those surveyed recently by "The Chronicle" and American Public Media's "Marketplace" said they had trouble finding recent graduates qualified to fill positions at their company or organization. Nearly a third gave colleges just fair to poor marks for producing…

  16. Disability Employment 101

    ERIC Educational Resources Information Center

    US Department of Education, 2007

    2007-01-01

    Business is about productivity and maintaining a competitive advantage. To do this, business needs qualified workers. Hiring people with disabilities adds value to a business and will attract new customers. Disability is not inability. Employers can make sound business decisions and gain a competitive advantage by using this guide to increase the…

  17. A Stochastic Employment Problem

    ERIC Educational Resources Information Center

    Wu, Teng

    2013-01-01

    The Stochastic Employment Problem(SEP) is a variation of the Stochastic Assignment Problem which analyzes the scenario that one assigns balls into boxes. Balls arrive sequentially with each one having a binary vector X = (X[subscript 1], X[subscript 2],...,X[subscript n]) attached, with the interpretation being that if X[subscript i] = 1 the ball…

  18. Employer Needs Assessment.

    ERIC Educational Resources Information Center

    Shaffer, Richard A.

    In 1990, Cuesta College (CC) conducted a needs assessment of local employers to determine the type of work done by their employees, number of employees, hiring plans, the current level of employee training, and training needs. The mailed survey had 266 usable responses for a 40.9% return rate. Study findings included the following: (1) 31% of the…

  19. Employment Prospects for Biologists.

    ERIC Educational Resources Information Center

    Korschgen, Ann J.; Davis, Jerry D.

    1983-01-01

    Assesses the results of a survey of organizations which hire individuals with a biological background, focusing on future hiring plans, level of education, employment selection factors, typical positions, and where jobs are listed. Recommends developing communication skills, maintaining high grades, and relevant work experience as keys to…

  20. Declining Black Employment.

    ERIC Educational Resources Information Center

    Vedder, Richard; Gallaway, Lowell

    1993-01-01

    Explores income inequality during declining African-American employment, examines current welfare systems, and suggests ways to improve the economic disadvantages of minority groups. Letting markets work can improve the economic status of African Americans. The present dual African-American economy, a market economy and an entitlement economy, is…

  1. Engaging Employers in Assessment

    ERIC Educational Resources Information Center

    Brown, Gary; DesRosier, Theron; Peterson, Nils; Chida, Meriem; Lagier, Randy

    2009-01-01

    In this article, the authors describe a pilot project in which formative feedback from industry professionals creates a genuine learning experience for students. Industry is giving feedback to higher education that many graduates are not employable or that they need substantial postcollegiate on-the-job training. Higher education is struggling to…

  2. Vietnamese Students Employability Skills

    ERIC Educational Resources Information Center

    Tuan, Nguyen Minh

    2011-01-01

    This paper attempts to investigate if the International University (IU) students' core competencies can meet the requirements set by employers, what are the differences in core competencies in final year students (or undergraduates), and how they view themselves compared with ex-students after one or two years in working environment, how…

  3. Industrialisation, Exports and Employment.

    ERIC Educational Resources Information Center

    Sabolo, Yves

    1980-01-01

    After reviewing trends in industrial production, exports, and employment in the Third World since 1960, the author discusses industrialization strategies based on the local processing of raw materials for export. Such processing has proved to be a major factor in job creation. (Author/SK)

  4. The Employability Skills Portfolio.

    ERIC Educational Resources Information Center

    Stemmer, Paul; And Others

    1992-01-01

    During 1990-91, Michigan schools piloted an innovative portfolio approach enabling students to discover, document, and develop employability skills in academics, personal management, and teamwork. Not an improved sorting system, the project encourages students to recognize successes, seek opportunities to improve skills, and gain confidence in…

  5. Equal Opportunity in Employment

    ERIC Educational Resources Information Center

    Bullock, Paul

    This book focuses on discrimination in employment, defined as the denial of equal opportunity in the labor market to qualified persons on the basis of race, color, religion, national origin, age, sex, or any other factor not related to their individual qualifications for work. The average nonwhite college graduate can expect to earn less during…

  6. FACTORS AFFECTING THE DEPOSITION OF INHALED POROUS DRUG PARTICLES

    EPA Science Inventory

    Abstract
    Recent findings indicate that the inhalation of large manufactured porous particles may be particularly effective for drug delivery. In this study, a mathematical model was employed to systematically investigate the effects of particle size, particle density, aerosol ...

  7. Archeointensity study on baked clay samples taken from the reconstructed ancient kiln: implication for validity of the Tsunakawa-Shaw paleointensity method

    NASA Astrophysics Data System (ADS)

    Yamamoto, Yuhji; Torii, Masayuki; Natsuhara, Nobuyoshi

    2015-05-01

    In 1972, a reconstruction experiment of a kiln had been done to reproduce an excavated kiln of the seventh century in Japan. Baked clay samples were taken from the floor surface and -20 cm level, and they have been stored after determinations of the paleomagnetic directions by partial alternating field demagnetizations. We recently applied the Tsunakawa-Shaw method to the samples to assess how reliable archeointensity results are obtained from the samples. A suite of the rock magnetic experiments and the scanning electron microscope observations elucidate that dominant magnetic carriers of the floor surface samples are Ti-poor titanomagnetite grains in approximately 10 nm size with single-domain and/or super-paramagnetic states, whereas contributions of multi-domain grains seem to be relatively large for the -20-cm level samples. From the floor surface samples, six out of the eight successful results were obtained and they give an average of 47.3 μT with a standard deviation of 2.2 μT. This is fairly consistent with the in situ geomagnetic field of 46.4 μT at the time of the reconstruction. They are obtained with a built-in anisotropy correction using anhysteretic remanent magnetization and without any cooling rate corrections. In contrast, only one out of four was successful from the -20-cm level samples. It yields an archeointensity of 31.6 μT, which is inconsistent with the in situ geomagnetic field. Considering from the in situ temperature record during the firing of the kiln and the unblocking temperature spectra of the samples, the floor surface samples acquired full thermoremanent magnetizations (TRMs) as their natural remanent magnetizations whereas the -20-cm level samples only acquired partial TRMs, and these differences probably cause the difference in the archeointensity results between the two sample groups. For archeointensity researches, baked clay samples from a kiln floor are considered to be ideal materials.

  8. Deca-brominated diphenyl ether destruction and PBDD/F and PCDD/F emissions from coprocessing deca-BDE mixture-contaminated soils in cement kilns.

    PubMed

    Yang, Yufei; Huang, Qifei; Tang, Zhenwu; Wang, Qi; Zhu, Xiaohua; Liu, Wenbin

    2012-12-18

    The disposal of soil contaminated with polybrominated diphenyl ether (PBDE) was studied using an industrial coprocessing cement kiln. Two tests, Test 1 and Test 2, studied the destruction, removal, and emissions of PBDE in soils with PBDE concentrations of 4160 and 25,000 mg/kg, respectively. Emissions of polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) were also quantified. The PBDE destruction and removal efficiencies for Tests 1 and 2 were 99.9997% and 99.9998%, respectively. PBDE stack gas concentrations were 39.1 and 85.9 ng/Nm³ for Tests 1 and 2, respectively. The mean PBDD/F TEQ stack gas concentrations related to Tests 1 and 2 were 11.0 and 11.4 pg/Nm³, and PBDFs contributed 60.0-64.2% of the total PBDD/F concentrations. 2,3,7,8-TeBDD made the greatest contribution to the total PBDD/Fs, 40%, of all the homologues. The mean PCDD/F TEQ stack gas concentrations in Tests 1 and 2 were 0.74 and 0.65 pg/Nm³. The total PBDE, PBDD/F, and PCDD/F TEQ at the kiln outlet was 0.006% and 0.001% of the feed material TEQ. Therefore, coprocessing heavily PBDE-contaminated soils in a cement kiln is a highly efficient and environmentally sound treatment technology.

  9. Microscopic analysis of "iron spot" on blue-and-white porcelain from Jingdezhen imperial kiln in early Ming dynasty (14th-15th century).

    PubMed

    Wang, Wenxuan; Zhu, Jian; Jiang, Jianxin; Xu, Changqing; Wu, Shurong; Guan, Li; Zhang, Zhaoxia; Wu, Menglei; Du, Jingnan

    2016-11-01

    "Sumali," as an imported cobalt ore from overseas, was a sort of precious and valuable pigment used for imperial kilns only, which produces characteristic "iron spot" to blue-and-white porcelain in early Ming Dynasty (A.D. 14th-15th century). Although there were some old studies on it, the morphology and formation of iron spot has not been fully investigated and understood. Therefore, five selected samples with typical spot from Jingdezhen imperial kiln in Ming Yongle periods (A.D. 1403-1424) were analyzed by various microscopic analysis including 3D digital microscope, SEM-EDS and EPMA. According to SEM images, samples can be divided into three groups: un-reflected "iron spot" without crystals, un-reflected "iron spot" with crystals and reflected "iron spot" with crystals. Furthermore, 3D micro-images revealed that "iron spots" separate out dendritic or snow-shaped crystals of iron only on and parallel to the surface of glaze for which "iron spot" show strong metallic luster. Combining with microscopic observation and microanalysis on crystallization and non-crystallization areas, it indicates that firing oxygen concentration is the ultimate causation of forming reflective iron spot which has a shallower distribution below the surface and limits crystals growing down. More details about characters of "iron spot" used "Sumali" were found and provided new clues to coloration, formation mechanism and porcelain producing technology of imperial kiln from 14th to 15th centuries of China.

  10. Cement kiln dust (CKD)-filter sand permeable reactive barrier for the removal of Cu(II) and Zn(II) from simulated acidic groundwater.

    PubMed

    Sulaymon, Abbas H; Faisal, Ayad A H; Khaliefa, Qusey M

    2015-10-30

    The hydraulic conductivity and breakthrough curves of copper and zinc contaminants were measured in a set of continuous column experiments for 99 days using cement kiln dust (CKD)-filter sand as the permeable reactive barrier. The results of these experiments proved that the weight ratios of the cement kiln dust-filter sand (10:90 and 20:80) are adequate in preventing the loss of reactivity and hydraulic conductivity and, in turn, avoiding reduction in the groundwater flow. These results reveal a decrease in the hydraulic conductivity, which can be attributed to an accumulation of most of the quantity of the contaminant masses in the first sections of the column bed. Breakthrough curves for the description of the temporal contaminant transport within the barrier were found to be more representative by the Belter-Cussler-Hu and Yan models based on the coefficient of determination and Nash-Sutcliffe efficiency. The longevity of the barrier was simulated for the field scale, based on the laboratory column tests and the values verified that cement kiln dust can be effectively used in the future, as the reactive material in permeable reactive barrier technology. These results signify that the longevity of the barrier is directly proportional to its thickness and inversely to the percentage of the CKD used.

  11. Case study of an MBT plant producing SRF for cement kiln co-combustion, coupled with a bioreactor landfill for process residues.

    PubMed

    Grosso, Mario; Dellavedova, Stefano; Rigamonti, Lucia; Scotti, Sergio

    2016-01-01

    The paper describes the performances of the energy recovery pathway from the residual waste based on the production of a Solid Recovered Fuel (SRF) to be exploited via co-combustion in a cement kiln. The SRF is produced in a single stream Mechanical-Biological Treatment plant, where bio-drying of the waste is followed by mechanical refining in order to fulfil the quality requirements by the cement kilns. Peculiar of this MBT is the fact that sorting residues are disposed in a nearby landfill, managed according to a bioreactor approach, where landfill gas is collected for electric energy recovery. A detailed mass and energy balance of the system is presented based on one year operational data, followed by its Life Cycle Assessment. Results show that the system is energetically and environmentally effective, with most of the impacts being more than compensated by the savings of materials and energy. Major role in determining such outcome is the displacement of petcoke in the cement kiln, both in terms of its fossil CO2 emissions and of its life cycle impacts, including the trans-oceanic transport. To check the robustness of the results, two sensitivity analyses are performed on the landfill gas collection efficiency and on the avoided electric energy mix.

  12. Particle cloud mixing in microgravity

    NASA Technical Reports Server (NTRS)

    Ross, H.; Facca, L.; Tangirala, V.; Berlad, A. L.

    1989-01-01

    Quasi-steady flame propagation through clouds of combustible particles requires quasi-steady transport properties and quasi-steady particle number density. Microgravity conditions may be employed to help achieve the conditions of quiescent, uniform clouds needed for such combustion studies. Joint experimental and theoretical NASA-UCSD studies were concerned with the use of acoustic, electrostatic, and other methods of dispersion of fuel particulates. Results of these studies are presented for particle clouds in long cylindrical tubes.

  13. Particle separation

    DOEpatents

    Moosmuller, Hans [Reno, NV; Chakrabarty, Rajan K [Reno, NV; Arnott, W Patrick [Reno, NV

    2011-04-26

    Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

  14. Particle separation

    NASA Technical Reports Server (NTRS)

    Moosmuller, Hans (Inventor); Chakrabarty, Rajan K. (Inventor); Arnott, W. Patrick (Inventor)

    2011-01-01

    Embodiments of a method for selecting particles, such as based on their morphology, is disclosed. In a particular example, the particles are charged and acquire different amounts of charge, or have different charge distributions, based on their morphology. The particles are then sorted based on their flow properties. In a specific example, the particles are sorted using a differential mobility analyzer, which sorts particles, at least in part, based on their electrical mobility. Given a population of particles with similar electrical mobilities, the disclosed process can be used to sort particles based on the net charge carried by the particle, and thus, given the relationship between charge and morphology, separate the particles based on their morphology.

  15. Full Employment in Industrialized Countries.

    ERIC Educational Resources Information Center

    Britton, Andrew

    1997-01-01

    Argues that full employment must be acceptable on both social and economic grounds. Examines profound changes in industrialized economies since the 1970s and the diversity of employment contracts. Suggests that difficult policy decisions surround full employment. (SK)

  16. Utilizing TEMPO surface estimates to determine changes in emissions, community exposure and environmental impacts from cement kilns across North America using alternative fuels

    NASA Astrophysics Data System (ADS)

    Pegg, M. J.; Gibson, M. D.; Asamany, E.

    2015-12-01

    A major problem faced by all North American (NA) Governments is managing solid waste from residential and non-residential sources. One way to mitigate the need to expand landfill sites across NA is waste diversion for use as alternative fuel in industries such as cement manufacture. Currently, waste plastic, tires, waste shingles and other high carbon content waste destined for landfill are being explored, or currently used, as an alternative supplemental fuels for use in cement kilns across NA. While this is an attractive, environmentally sustainable solution, significant knowledge gaps remain in our fundamental understanding of whether these alternative fuels may lead to increased air pollution emissions from cement kilns across NA. The long-term objective of using TEMPO is to advance fundamental understanding of uncharacterized air pollution emissions and to assess the actual or potential environmental and health impacts of these emissions from cement kilns across NA. TEMPO measurements will be made in concert with in-situ observations augmented by air dispersion, land-use regression and receptor modelling. This application of TEMPO follows on from current research on a series of bench scale and pilot studies for Lafarge Canada Inc., that investigated the change in combustion emissions from various mixtures of coal (C), petroleum coke (PC) and non-recyclable alternative fuels. From our work we demonstrated that using an alternative fuel mixture in a cement kiln has potential to reduce emissions of CO2 by 34%; reduce NOx by 80%, and reduce fuel SO2 emissions by 98%. We also provided evidence that there would be a significant reduction in the formation of secondary ground-level ozone (O3) and secondary PM2.5 in downwind stack plumes if alternative waste derived fuels are used. The application of air dispersion, source apportionment, land use regression; together with remote sensing offers a powerful set of tools with the potential to improve air pollution

  17. Employment security and health

    PubMed Central

    Virtanen, P; Vahtera, J; Kivimaki, M; Pentti, J; Ferrie, J

    2002-01-01

    Design: Cross sectional survey. Setting: Municipal sector employees in eight Finnish towns. Participants: 5981 employees with a permanent contract and 2786 employees with a non-permanent contract (2194 fixed term contract, 682 government subsidised contract). Outcome measures: Poor self rated health, chronic disease, and psychological distress. Results: Compared with permanent employees, fixed term men and women had better self rated health (men odds ratio 0.70; 95% confidence intervals 0.50 to 0.98, women 0.70 (0.60 to 0.82) and less chronic disease (men 0.69; 0.52 to 0.91; women 0.89; 0.79 to 1.02), but women had more psychological distress (1.26; 1.09 to 1.45). The only difference between subsidised employees and permanent employees was the high level of psychological distress in women (1.35; 1.09 to 1.68). Low perceived employment security was associated with poor health across all three indicators. The association of low perceived security with psychological distress was significantly stronger in permanent employees than among fixed term and subsidised employees, indicating that perceived security is more important for mental health among employees with a permanent contract. Conclusions: Contractual security and perceived security of employment are differently associated with health. It is therefore important to distinguish between these aspects of employment security in studies of labour market status and health. Such studies will also need to control for health selection, which is unlikely to operate in the same way among permanent and non-permanent employees. PMID:12118045

  18. Graduate Employability: A Conceptual Framework for Understanding Employers' Perceptions

    ERIC Educational Resources Information Center

    Cai, Yuzhuo

    2013-01-01

    This study provides a conceptual framework for understanding what employers think about the value of graduates with similar educational credentials in the workplace (their employability), using insights from the new institutionalism. In this framework, the development of employers' beliefs about graduates' employability is broken into a number of…

  19. Characteristics of ammonia emission during thermal drying of lime sludge for co-combustion in cement kilns.

    PubMed

    Liu, Wei; Xu, Jingcheng; Liu, Jia; Cao, Haihua; Huang, Xiang-Feng; Li, Guangming

    2015-01-01

    Thermal drying was used to reduce sludge moisture content before co-combustion in cement kilns. The characteristics of ammonia (NH3) emission during thermal drying of lime sludge (LS) were investigated in a laboratory-scale tubular dry furnace under different temperature and time conditions. As the temperature increased, the NH3 concentration increased in the temperature range 100-130°C, decreased in the temperature range 130-220°C and increased rapidly at >220°C. Emission of NH3 also increased as the lime dosage increased and stabilized at lime dosages>5%. In the first 60 min of drying experiments, 55% of the NH3 was released. NH3 accounted for about 67-72% of the change in total nitrogen caused by the release of nitrogen-containing volatile compounds (VCs) from the sludge. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the main forms of nitrogen in sludge were amides and amines. The addition of lime (CaO) could cause conversion of N-H, N-O or C-N containing compounds to NH3 during the drying process.

  20. Evaluation of sulfidic mine tailings solidified/stabilized with cement kiln dust and fly ash to control acid mine drainage

    SciTech Connect

    Nehdi, M.; Tariq, A.

    2008-11-15

    In the present research, industrial byproducts, namely, cement kiln dust (CKD) and Class C fly ash (FAC) have been used as candidate materials along with the partial addition of sulfate-resistant cement (SRC) in the Stabilization/solidification of polymetallic sulfidic mine tailings (MT). The effectiveness of S/S was assessed by comparing laboratory experimental values obtained from unconfined compressive strength, hydraulic conductivity and leaching propensity tests of S/S samples with regulatory standards for safe surface disposal of such wastes. Despite general regulatory compliance of compressive strength and hydraulic conductivity, some solidified/stabilized-cured matrices were found unable to provide the required immobilization of pollutants. Solidified/stabilized and 90-day cured mine tailings specimens made with composite binders containing (10% CKD + 10% FAC), (5% SRC + 15% FAC) and (5% SRC + 5% CKD + 10% FAC) significantly impaired the solubility of all contaminants investigated and proved successful in fixing metals within the matrix, in addition to achieving adequate unconfined compressive strength and hydraulic conductivity values, thus satisfying USEPA regulations. Laboratory investigations revealed that, for polymetallic mining waste, leachate concentrations are the most critical factor in assessing the effectiveness of S/S technology.

  1. Evaluation of hazardous waste incineration in cement kilns at San Juan Cement Company. Final report August 1981-March 1982

    SciTech Connect

    Peters, J.A.; Hughes, T.W.; McKendree, J.R.; Cox, L.A.; Hughes, B.M.

    1984-08-01

    Cement kiln incineration of chlorinated liquid organic wastes was investigated in a 5-month demonstration program at San Juan Cement Company in Puerto Rico. Chlorinated monocarbon compounds (POHC's) were monitored in the waste and emissions, and the fate of added chlorine in cement production was determined. Seven levels of percent chlorine in the waste were burned at ten different waste feed rates. Extensive sampling and analysis was conducted to look for the potential presence of polychlorinated dibenzodioxins (PCDD's) and polychlorinated dibenzofurans (PCDF's). The destruction and removal efficiencies (DRE) of the POHC's ranged from 91.043 percent to 99.997 percent, with only 6 percent of the DRE's greater than 99.99 percent. Poor DRE results were attributed to the absence of waste atomization and the difficult incinerability of chlorinated monocarbon compounds. It was found that about 82 percent of the input chlorine appeared in the cement clinker. The amount of chlorine appearing in the baghouse dust varied from 5 percent to 26 percent of total chlorine input. The total absorption of the HCl formed averaged 99.7 percent in seven tests. PCDD's and PCDF's were not produced at detectable levels when the cement plant was operating normally.

  2. Bench-scale study of active mine water treatment using cement kiln dust (CKD) as a neutralization agent.

    PubMed

    Mackie, Allison L; Walsh, Margaret E

    2012-02-01

    The overall objective of this study was to investigate the potential impact on settled water quality of using cement kiln dust (CKD), a waste by-product, to replace quicklime in the active treatment of acidic mine water. Bench-scale experiments were conducted to evaluate the treatment performance of calcium hydroxide (Ca(OH)(2)) slurries generated using four different CKD samples compared to a control treatment with quicklime (CaO) in terms of reducing acidity and metals concentrations in acid mine drainage (AMD) samples taken from the effluent of a lead/zinc mine in Atlantic Canada. Results of the study showed that all of the CKD samples evaluated were capable of achieving greater than 97% removal of total zinc and iron. The amount of solid alkaline material required to achieve pH targets required for neutralization of the AMD was found to be higher for treatment with the CKD slurries compared to the quicklime slurry control experiments, and varied linearly with the free lime content of the CKD. The results of this study also showed that a potential benefit of treating mine water with CKD could be reduced settled sludge volumes generated in the active treatment process, and further research into the characteristics of the sludge generated from the use of CKD-generated calcium hydroxide slurries is recommended.

  3. Particle generator

    DOEpatents

    Hess, Wayne P.; Joly, Alan G.; Gerrity, Daniel P.; Beck, Kenneth M.; Sushko, Peter V.; Shlyuger, Alexander L.

    2005-06-28

    Energy tunable solid state sources of neutral particles are described. In a disclosed embodiment, a halogen particle source includes a solid halide sample, a photon source positioned to deliver photons to a surface of the halide, and a collimating means positioned to accept a spatially defined plume of hyperthermal halogen particles emitted from the sample surface.

  4. Undergraduates' Perceptions of Employer Expectations

    ERIC Educational Resources Information Center

    DuPre, Carrie; Williams, Kate

    2011-01-01

    Research conducted by the National Association of Colleges and Employers (NACE) indicates that employers across industries seek similar skills in job applicants; yet employers often report finding these desired skills lacking in new hires. This study closes the gap in understanding between employer expectations and student perceptions regarding…

  5. Employability Skills Assessment Tool Development

    ERIC Educational Resources Information Center

    Rasul, Mohamad Sattar; Rauf, Rose Amnah Abd; Mansor, Azlin Norhaini; Puvanasvaran, A. P.

    2012-01-01

    Research nationally and internationally found that technical graduates are lacking in employability skills. As employability skills are crucial in outcome-based education, the main goal of this research is to develop an Employability Skill Assessment Tool to help students and lecturers produce competent graduates in employability skills needed by…

  6. Employability. NIACE Briefing Sheet 88

    ERIC Educational Resources Information Center

    National Institute of Adult Continuing Education, 2009

    2009-01-01

    Employability skills are central to gaining and keeping employment (e.g. whether paid or unpaid, as an employee or self employed) as well as career progression. The lack of such skills is regularly referred to as one reason for the United Kingdom's often cited long tail of underachievement. Employability skills are at the forefront of government…

  7. Employment Trajectories Beyond Retirement.

    PubMed

    Burkert, Carola; Hochfellner, Daniela

    2017-01-01

    Within the political and academic debate on working longer, post-retirement employment is discussed as an alternative to maintain older workers in the labor market. Our article enhances this discussion by studying determinants of transitions into post-retirement jobs within differing work environments of birth cohorts 1940-1942. We estimate proportional subhazard models accounting for competing risks using unique German social security data linked to pension accounts. Our findings suggest that individuals' preferences to take up post-retirement jobs are not mutually exclusive. Our study provides evidence that taking up post-retirement jobs is related to seeking financial security, continuity, and work ability, suggesting that public policy has to develop target-oriented support through a public policy mix of different measures aligned to the different peer groups in the labor market.

  8. Towards pollution prevention in batch charcoal kilns: A rigorous description of wood pyrolysis

    SciTech Connect

    Bhatia, G.; Turner, J.R.

    1999-07-01

    In this paper, the process of charcoal manufacture is addressed primarily from a fundamental perspective. A particle scale model to describe wood pyrolysis has been developed to describe the physicochemical dynamics taking place when a single piece of wood is exposed to a heat flux in an inert atmosphere. The model uses lumped kinetics to handle the complexity of reactions taking place in the process. The kinetics are coupled with a description of the physical processes such as heat and mass transfer occurring inside the wood. Spatial and temporal profiles for the yields of char, tar and gases as well as temperature profiles are obtained from numerical simulations. Kinetic constants and physical properties reported in the literature are used in the computations. Modeling results for the overall yield of char show reasonably good agreement with values obtained from a bench-scale experimental set-up.

  9. Competitive Employment and Autism Spectrum Disorder: Employer Perspectives

    ERIC Educational Resources Information Center

    Stuckey, Wanietta C.

    2016-01-01

    Competitive employment for individuals with Autism Spectrum Disorder (ASD) is important because this group is described as the most employable, yet least employed. Historically, females have been more likely to hire/work with individuals with disabilities than males but the gap between the sexes has been closing. A survey focusing on work…

  10. Consumer and Employer Strategies for Overcoming Employment Barriers. Technical Report.

    ERIC Educational Resources Information Center

    Crudden, Adele; Williams, Wendy; McBroom, Lynn W.; Moore, J. Elton

    This report on strategies for overcoming employment barriers for persons with visual impairments summarizes comments and suggestions of 7 focus groups comprised of either consumers (n=49) or employers (n=19). The report first reviews the literature concerning employment barriers and how consumers in previous studies suggested these barriers be…

  11. Barriers to Employment: Personality and Cognitive Predictors of Employment Status

    ERIC Educational Resources Information Center

    McTurk, Carolyn; Shakespeare-Finch, Jane

    2006-01-01

    Barriers to employment are linked to individual factors such as thinking styles and personality traits. Personality and cognitive differences between employed (n = 55) and unemployed (n = 57) cohorts were analysed to quantify the association between these variables and employment status. Using the Myers-Briggs Type Indicator (MBTI) and the…

  12. Disability and Supported Employment: Impact on Employment, Income, and Allowances

    ERIC Educational Resources Information Center

    Germundsson, Per; Gustafsson, Johanna; Lind, Martin; Danermark, Berth

    2012-01-01

    In this article, we examine supported employment and its impact on the level of employment, disposable income, and sum of allowances, targeting a group of individuals with disabilities. We have particularly focused on individuals with psychiatric disabilities. Supported employment is a vocational rehabilitation service with an empowerment approach…

  13. A Conceptual Understanding of Employability: The Employers' View in Rwanda

    ERIC Educational Resources Information Center

    Bamwesiga, Penelope Mbabazi

    2013-01-01

    Many governments believe that investing in human capital should increase citizens' employability, which is why it is often presented as a solution to the problems of knowledge-based economies and societies, rising unemployment rates and economic competiveness. The aim of this study is to understand employers' views regarding the employability of…

  14. Particle astrophysics

    NASA Technical Reports Server (NTRS)

    Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

    1991-01-01

    The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

  15. Particle astrophysics

    NASA Astrophysics Data System (ADS)

    Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

    The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

  16. Particle separator

    DOEpatents

    Hendricks, Charles D.

    1990-01-01

    Method and apparatus (10) are provided for separating and classifying particles (48,50,56) by dispersing the particles within a fluid (52) that is upwardly flowing within a cone-shaped pipe (12) that has its large end (20) above its small end (18). Particles of similar size and shape (48,50) migrate to individual levels (A,B) within the flowing fluid. As the fluid is deflected by a plate (42) at the top end of the pipe (12), the smallest particles are collected on a shelf-like flange (40). Ever larger particles are collected as the flow rate of the fluid is increased. To prevent particle sticking on the walls (14) of the pipe (12), additional fluid is caused to flow into the pipe (12) through holes (68) that are specifically provided for that purpose. Sticking is further prevented by high frequency vibrators (70) that are positioned on the apparatus (10).

  17. Particle therapy

    SciTech Connect

    Raju, M.R.

    1993-09-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics.

  18. Integral equation study of particle confinement effects in a polymer/particle mixture

    SciTech Connect

    Henderson, D; Trokhymchuk, A; Kalyuzhnyi, Y; Gee, R; Lacevic, N

    2007-05-09

    Integral equation theory techniques are applied to evaluate the structuring of the polymer when large solid particles are embedded into a bulk polymer melt. The formalism presented here is applied to obtain an insight into the filler particle aggregation tendency. We find that with the employed polymer-particle interaction model it is very unlikely that the particles will aggregate. We believe that in such a system aggregation and clustering can occur when the filler particles are dressed by tightly bound polymer layers.

  19. Magnetic particles

    NASA Technical Reports Server (NTRS)

    Chang, Manchium (Inventor); Colvin, Michael S. (Inventor)

    1989-01-01

    Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.

  20. On particle track detectors

    NASA Technical Reports Server (NTRS)

    Benton, E. V.; Gruhn, T. A.; Andrus, C. H.

    1973-01-01

    Aqueous sodium hydroxide is widely used to develop charged particle tracks in polycarbonate film, particularly Lexan. The chemical nature of the etching process for this system has been determined. A method employing ultra-violet absorbance was developed for monitoring the concentration of the etch products in solution. Using this method it was possible to study the formation of the etching solution saturated in etch products. It was found that the system super-saturates to a significant extent before precipitation occurs. It was also learned that the system approaches its equilibrium state rather slowly. It is felt that both these phenomena may be due to the presence of surfactant in the solution. In light of these findings, suggestions are given regarding the preparation and maintenance of the saturated etch solution. Two additional research projects, involving automated techniques for particle track analysis and particle identification using AgCl crystals, are briefly summarized.

  1. Biological particle identification apparatus

    DOEpatents

    Salzman, Gary C.; Gregg, Charles T.; Grace, W. Kevin; Hiebert, Richard D.

    1989-01-01

    An apparatus and method for making multiparameter light scattering measurements from suspensions of biological particles is described. Fourteen of the sixteen Mueller matrix elements describing the particles under investigation can be substantially individually determined as a function of scattering angle and probing radiations wavelength, eight elements simultaneously for each of two apparatus configurations using an apparatus which incluees, in its simplest form, two polarization modulators each operating at a chosen frequency, one polarizer, a source of monochromatic electromagnetic radiation, a detector sensitive to the wavelength of radiation employed, eight phase-sensitive detectors, and appropriate electronics. A database of known biological particle suspensions can be assembled, and unknown samples can be quickly identified once measurements are performed on it according to the teachings of the subject invention, and a comparison is made with the database.

  2. Assessment of cement kiln dust (CKD) for stabilization/solidification (S/S) of arsenic contaminated soils.

    PubMed

    Moon, Deok Hyun; Wazne, Mahmoud; Yoon, In-Ho; Grubb, Dennis G

    2008-11-30

    A stabilization/solidification (S/S) process for arsenic (As) contaminated soils was evaluated using cement kiln dust (CKD). Laboratory-prepared slurries, made of either kaolinite or montmorillonite, and field soils spiked with either As(3+) or As(5+) were prepared and treated with CKD ranging from 10 to 25 wt%. Sodium arsenite and sodium arsenate at 0.1 wt% were used to simulate arsenite (As(3+)) and arsenate (As(5+)) source contamination in soils, respectively. The effectiveness of treatment was evaluated at curing periods of 1- and 7-days based on the toxicity characteristic leaching procedure (TCLP). As-CKD and As-clay-CKD slurries were also spiked at 10 wt% to evaluate As immobilization mechanism using X-ray powder diffraction (XRPD) analyses. Overall, the TCLP results showed that only the As(5+) concentrations in kaolinite amended with 25 wt% CKD after 1 day of curing were less than the TCLP regulatory limit of 5mg/L. Moreover, at 7 days of curing, all As(3+) and As(5+) concentrations obtained from kaolinite soils were less than the TCLP criteria. However, none of the CKD-amended montmorillonite samples satisfied the TCLP-As criteria at 7 days. Only field soil samples amended with 20 wt% CKD complied with the TCLP criteria within 1 day of curing, where the source contamination was As(5+). XRPD and scanning electron microscopy (SEM)-energy dispersive X-ray spectroscopy (EDX) results showed that Ca-As-O and NaCaAsO(4).7.5H(2)O were the primary phases responsible for As(3+) and As(5+) immobilization in the soils, respectively.

  3. Failure to phytosanitize ash firewood infested with emerald ash borer in a small dry kiln using ISPM-15 standards.

    PubMed

    Goebel, P Charles; Bumgardner, Matthew S; Herms, Daniel A; Sabula, Andrew

    2010-06-01

    Although current USDA-APHIS standards suggest that a core temperature of 71.1 degrees C (160 degrees F) for 75 min is needed to adequately sanitize emerald ash borer, Agrilus planipennis Fairmaire-infested firewood, it is unclear whether more moderate (and economical) treatment regimes will adequately eradicate emerald ash borer larvae and prepupae from ash firewood. We constructed a small dry kiln in an effort to emulate the type of technology a small- to medium-sized firewood producer might use to examine whether treatments with lower temperature and time regimes successfully eliminate emerald ash borer from both spilt and roundwood firewood. Using white ash (Fraxinus americana L.) firewood collected from a stand with a heavy infestation of emerald ash borer in Delaware, OH, we treated the firewood using the following temperature and time regime: 46 degrees C (114.8 degrees F) for 30 min, 46 degrees C (114.8 degrees F) for 60 min, 56 degrees C (132.8 degrees F) for 30 min, and 56 degrees C (132.8 degrees F) for 60 min. Temperatures were recorded for the outer 2.54-cm (1-in.) of firewood. After treatment, all firewood was placed under mesh netting and emerald ash borer were allowed to develop and emerge under natural conditions. No treatments seemed to be successful at eliminating emerald ash borer larvae and perpupae as all treatments (including two nontreated controls) experienced some emerald ash borer emergence. However, the 56 degrees C (132.8 degrees F) treatments did result in considerably less emerald ash borer emergence than the 46 degrees C (114.8 degrees F) treatments. Further investigation is needed to determine whether longer exposure to the higher temperature (56 degrees C) will successfully sanitize emerald ash borer-infested firewood.

  4. Mechanism for the stabilization/solidification of arsenic-contaminated soils with Portland cement and cement kiln dust.

    PubMed

    Yoon, In-Ho; Moon, Deok Hyun; Kim, Kyoung-Woong; Lee, Keun-Young; Lee, Ji-Hoon; Kim, Min Gyu

    2010-11-01

    In this study, the mechanism for the stabilization/solidification (S/S) of arsenic (As)-contaminated soils with Portland cement (PC), and cement kiln dust (CKD) using 1 N HCl extraction fluid, X-ray powder diffraction (XRPD), X-ray absorption near edge structure (XANES) and Extended X-ray absorption fine structure (EXAFS) spectroscopy was investigated. The degree of As immobilization after stabilization was assessed using a 1 N HCl extraction on the basis of the Korean Standard Test (KST). After 1 day of curing with 30 wt% PC and 7 days of curing with 50 wt% CKD, the concentration of As leached from the amended soils was less than the Korean countermeasure standard (3 mg L(-1)). The As concentrations in the leachate treated with PC and CKD were significantly decreased at pH > 3, indicating that pH had a prevailing influence on As mobility. XRPD results indicated that calcium arsenite (Ca-As-O) and sodium calcium arsenate hydrate (NaCaAsO(4).7.5H(2)O) were present in the PC- and CKD-treated slurries as the key phases responsible for As(III) and As(V) immobilization, respectively. The XANES spectroscopy confirmed that the As(III) and As(V) oxidation states of the PC and CKD slurry samples were consistent with the speciated forms in the crystals identified by XRPD. EXAFS spectroscopy showed As-Ca bonding in the As(III)-PC and As(III)-CKD slurries. The main mechanism for the immobilization of As-contaminated soils with PC and CKD was strongly associated with the bonding between As(III) or As(V) and Ca.

  5. Interaction of Burning Metal Particles

    NASA Technical Reports Server (NTRS)

    Dreizin, Edward L.; Berman, Charles H.; Hoffmann, Vern K.

    1999-01-01

    Physical characteristics of the combustion of metal particle groups have been addressed in this research. The combustion behavior and interaction effects of multiple metal particles has been studied using a microgravity environment, which presents a unique opportunity to create an "aerosol" consisting of relatively large particles, i.e., 50-300 m diameter. Combustion behavior of such an aerosol could be examined using methods adopted from well-developed single particle combustion research. The experiment included fluidizing relatively large (order of 100 m diameter) uniform metal particles under microgravity and igniting such an "aerosol" using a hot wire igniter. The flame propagation and details of individual particle combustion and particle interaction have been studied using a high speed movie and video-imaging with cameras coupled with microscope lenses to resolve individual particles. Interference filters were used to separate characteristic metal and metal oxide radiation bands from the thermal black body radiation. Recorded flame images were digitized and various image processing techniques including flame position tracking, color separation, and pixel by pixel image comparison were employed to understand the processes occurring in the burning aerosol. The development of individual particle flames, merging or separation, and extinguishment as well as induced particle motion have been analyzed to identify the mechanisms governing these processes. Size distribution, morphology, and elemental compositions of combustion products were characterized and used to link the observed in this project aerosol combustion phenomena with the recently expanded mechanism of single metal particle combustion.

  6. Interaction of Burning Metal Particles

    NASA Technical Reports Server (NTRS)

    Dreizin, Edward L.; Berman, Charles H.; Hoffmann, Vern K.

    1999-01-01

    Physical characteristics of the combustion of metal particle groups have been addressed in this research. The combustion behavior and interaction effects of multiple metal particles has been studied using a microgravity environment, which presents a unique opportunity to create an "aerosol" consisting of relatively large particles, i.e., 50-300 micrometer diameter. Combustion behavior of such an aerosol could be examined using methods adopted from well-developed single particle combustion research. The experiment included fluidizing relatively large (order of 100 micrometer diameter) uniform metal particles under microgravity and igniting such an "aerosol" using a hot wire igniter. The flame propagation and details of individual particle combustion and particle interaction have been studied using a high speed movie and video-imaging with cameras coupled with microscope lenses to resolve individual particles. Interference filters were used to separate characteristic metal and metal oxide radiation bands form the thermal black body radiation. Recorded flame images were digitized and employed to understand the processes occurring in the burning aerosol. The development of individual particle flames, merging or separation, and extinguishing as well as induced particle motion have been analyzed to identify the mechanisms governing these processes. Size distribution, morphology, and elemental compositions of combustion products were characterized and used to link the observed in this project aerosol combustion phenomena with the recently expanded mechanism of single metal particle combustion.

  7. Third Annual Employer Satisfaction Survey.

    ERIC Educational Resources Information Center

    Broadbent, William A.

    A study was conducted in 1980 to ascertain employer attitudes toward and satisfaction with the performance of graduates of vocational education programs in Hawaii. Interviews with 41 employers, who employed an average of 132 workers, sought general perceptions of the knowledge, quality of work, written and oral skills, dependability, adaptability,…

  8. Employment Impact of Electronic Business.

    ERIC Educational Resources Information Center

    Hecker, Daniel E.

    2001-01-01

    Electronic business is stimulating employment in some sectors across industries, such as computer-related and customer service occupations, and diminishing employment in others, such as administrative support and marketing/sales. Similarly, employment impacts will vary by industry. (Contains 56 notes and references.) (SK)

  9. Particle preconcentrator

    DOEpatents

    Linker, Kevin L.; Conrad, Frank J.; Custer, Chad A.; Rhykerd, Jr., Charles L.

    2000-01-01

    An apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  10. Particle preconcentrator

    SciTech Connect

    Linker, K.L.; Conrad, F.J.; Custer, C.A.; Rhykerd, C.L. Jr.

    1998-12-29

    An apparatus and method are disclosed for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents. 3 figs.

  11. Particle preconcentrator

    SciTech Connect

    Linker, Kevin L.; Conrad, Frank J.; Custer, Chad A.; Rhykerd, Jr., Charles L.

    1998-01-01

    An apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  12. Particle preconcentrator

    SciTech Connect

    Linker, Kevin L.; Conrad, Frank J.; Custer, Chad A.; Rhykerd, Jr., Charles L.

    2005-09-20

    An apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  13. Particle preconcentrator

    SciTech Connect

    Linker, K.L.; Conrad, F.J.; Custer, C.A.; Rhykerd, C.L. Jr

    2000-07-11

    An apparatus and method are disclosed for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a previous screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  14. Particle detection systems and methods

    DOEpatents

    Morris, Christopher L.; Makela, Mark F.

    2010-05-11

    Techniques, apparatus and systems for detecting particles such as muons and neutrons. In one implementation, a particle detection system employs a plurality of drift cells, which can be for example sealed gas-filled drift tubes, arranged on sides of a volume to be scanned to track incoming and outgoing charged particles, such as cosmic ray-produced muons. The drift cells can include a neutron sensitive medium to enable concurrent counting of neutrons. The system can selectively detect devices or materials, such as iron, lead, gold, uranium, plutonium, and/or tungsten, occupying the volume from multiple scattering of the charged particles passing through the volume and can concurrently detect any unshielded neutron sources occupying the volume from neutrons emitted therefrom. If necessary, the drift cells can be used to also detect gamma rays. The system can be employed to inspect occupied vehicles at border crossings for nuclear threat objects.

  15. Correlation studies on surface particle detection methods

    NASA Technical Reports Server (NTRS)

    Peterson, Ronald V.; White, James C.

    1988-01-01

    The accurate determination of dust levels on optical surfaces is necessary to assess sensor system performance. A comparison study was made on several particle measurement methods including those based on direct imaging and light scattering. The effectiveness of removing the particles from the surface prior to determining particle size distributions was also assessed. These studies revealed that some methods, especially those requiring particle removal before analysis, are subject to large systematic errors affecting particle size distributions. Thus, an understanding of the particle measurement methods employed is necessary before any surface cleanliness or obstruction value assignments are accepted as true representations of an optical surface contamination condition.

  16. Lorentz force particle analyzer

    NASA Astrophysics Data System (ADS)

    Wang, Xiaodong; Thess, André; Moreau, René; Tan, Yanqing; Dai, Shangjun; Tao, Zhen; Yang, Wenzhi; Wang, Bo

    2016-07-01

    A new contactless technique is presented for the detection of micron-sized insulating particles in the flow of an electrically conducting fluid. A transverse magnetic field brakes this flow and tends to become entrained in the flow direction by a Lorentz force, whose reaction force on the magnetic-field-generating system can be measured. The presence of insulating particles suspended in the fluid produce changes in this Lorentz force, generating pulses in it; these pulses enable the particles to be counted and sized. A two-dimensional numerical model that employs a moving mesh method demonstrates the measurement principle when such a particle is present. Two prototypes and a three-dimensional numerical model are used to demonstrate the feasibility of a Lorentz force particle analyzer (LFPA). The findings of this study conclude that such an LFPA, which offers contactless and on-line quantitative measurements, can be applied to an extensive range of applications. These applications include measurements of the cleanliness of high-temperature and aggressive molten metal, such as aluminum and steel alloys, and the clean manufacturing of semiconductors.

  17. Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): Emissions of particulate matter from wood and dung cooking fires, brick kilns, generators, trash and crop residue burning

    NASA Astrophysics Data System (ADS)

    Stone, Elizabeth; Jayarathne, Thilina; Stockwell, Chelsea; Christian, Ted; Bhave, Prakash; Siva Praveen, Puppala; Panday, Arnico; Adhikari, Sagar; Maharjan, Rashmi; Goetz, Doug; DeCarlo, Peter; Saikawa, Eri; Yokelson, Robert

    2016-04-01

    The Nepal Ambient Monitoring and Source Testing Experiment (NAMASTE) field campaign targeted the in situ characterization of widespread and under-sampled combustion sources. In Kathmandu and the Terai, southern Nepal's flat plains, samples of fine particulate matter (PM2.5) were collected from wood and dung cooking fires (n = 22), generators (n = 2), groundwater pumps (n = 2), clamp kilns (n = 3), zig-zag kilns (n = 3), trash burning (n = 4), one heating fire, and one crop residue fire. Co-located measurements of carbon dioxide, carbon monoxide, and volatile organic compounds allowed for the application of the carbon mass balance approach to estimate emission factors for PM2.5, elemental carbon, organic carbon, and water-soluble inorganic ions. Organic matter was chemically speciated using gas chromatography - mass spectrometry for polycyclic aromatic hydrocarbons, sterols, n-alkanes, hopanes, steranes, and levoglucosan, which accounted for 2-8% of the measured organic carbon. These data were used to develop molecular-marker based profiles for use in source apportionment modeling. This study provides quantitative emission factors for particulate matter and its constituents for many important combustion sources in Nepal and South Asia.

  18. Magnetic particles

    NASA Technical Reports Server (NTRS)

    Chang, Manchium (Inventor); Colvin, Michael S. (Inventor); Rembaum, Alan (Inventor); Richards, Gil F. (Inventor)

    1987-01-01

    Metal oxide containing polymers and particularly styrene, acrylic or protein polymers containing fine, magnetic iron oxide particles are formed by combining a NO.sub.2 -substituted polymer with an acid such as hydrochloric acid in the presence of metal, particularly iron particles. The iron is oxidized to fine, black Fe.sub.3 O.sub.4 particles which deposit selectively on the polymer particles. Nitrated polymers are formed by reacting functionally substituted, nitrated organic compounds such as trinitrobenzene sulfonate or dinitrofluoro benzene with a functionally coreactive polymer such as an amine modified acrylic polymer or a protein. Other transition metals such as cobalt can also be incorporated into polymers using this method.

  19. Young People and Employment (1): Employers' Use of Educational Qualifications.

    ERIC Educational Resources Information Center

    Reed, Eileen

    1980-01-01

    A survey of recruitment officers in England and Wales concerning the entry to employment of young people who leave school with no formal qualifications or with qualifications below the GCE A level is discussed. Findings suggest that employers are not dissatisfied with their recruits. (Author/MLW)

  20. 29 CFR 1607.10 - Employment agencies and employment services.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... these guidelines. An employment agency is not relieved of its obligation herein because the user did not... other user of its responsibilities under Federal law to provide equal employment opportunity or its obligations as a user under these guidelines. B. Where selection procedures are devised elsewhere. Where...

  1. Conceptualizing Learning and Employability "Learning and Employability Framework"

    ERIC Educational Resources Information Center

    Sumanasiri, Erabaddage Gishan Tharanga; Yajid, Mohd Shukri Ab; Khatibi, Ali

    2015-01-01

    Extensive studies have been done on employability and the factors that lead to employability. Previous studies have focused on career development programs, internships, work experience programs, soft-skill development programs, and even university admission criteria which can be considered external factors to university student learning…

  2. Graduates' Employment and the Discourse of Employability: A Critical Analysis

    ERIC Educational Resources Information Center

    Moreau, Marie-Pierre; Leathwood, Carole

    2006-01-01

    In a context of considerable changes in the labour market and higher education sector in the UK, a discourse of employability has become increasingly dominant. Universities are urged to ensure that they produce "employable" graduates, and graduates themselves are exhorted to continually develop their personal skills, qualities and…

  3. Linking with Employment: Training from the Perspective of Employers.

    ERIC Educational Resources Information Center

    Herschbach, Dennis R.

    Employers need training, want it, and are willing to pay for it providing it is relevant to their requirements, results in improved product quality, and fosters increased productivity. Firm characteristics make a difference not only with regard to the kinds of skills wanted by employers but also with regard to how training can best be delivered.…

  4. Spatial analysis of charcoal kiln remains in the former royal forest district Tauer (Lower Lusatia, North German Lowlands)

    NASA Astrophysics Data System (ADS)

    Raab, Alexandra; Schneider, Anna; Bonhage, Alexander; Takla, Melanie; Hirsch, Florian; Müller, Frank; Rösler, Horst; Heußner, Karl-Uwe

    2016-04-01

    Archaeological excavations have revealed more than thousand charcoal kiln remains (CKRs) in the prefield of the active opencast lignite mine Jänschwalde, situated about 150 km SE of Berlin (SE Brandenburg, Germany). The charcoal was mainly produced for the ironwork Peitz nearby, which operated from the 16th to the mid-19th centuries. In a first approach, to estimate the dimension of the charcoal production, CKRs were mapped on shaded-relief maps (SRMs) derived from high-resolution LiDAR data (Raab et al. 2015). Subsequently, for a selected test area, identified CKRs on the SRMs were compared with archaeologically excavated CKRs in the field. This survey showed a considerably number of falsely detected sites. Therefore, the data was critically re-evaluated using additional relief visualisations. Further, we extended the CKR mapping to areas which are not archaeologically investigated. The study area, the former royal forest district Tauer, consists of two separate areas: the Tauersche Heide (c. 96 km2 area) N of Peitz and the area Jänschwalde (c. 32 km2 area) NE of Peitz. The study area is characterized by a flat topography. Different former and current anthropogenic uses (e.g., military training, solar power plant, forestry measures) have affected the study area, resulting in extensive disturbances of the terrain surface. The revised CKR abundance in the study area Jänschwalde was considerably smaller than the numbers produced by our first approach. Further, the CKR mapping revealed, that a total record of the CKRs is not possible for various reasons. Despite these limitations, a solid database can be provided for a much larger area than before. Basic statistic parameters of the CKR diameters and all comparative statistical tests were calculated using SPSS. To detect underlying spatial relationships in the CKR site distribution, we applied the Getis-Ord Gi* statistic, a method to test for local spatial autocorrelation between neighbouring sites. The test is

  5. Auroral particles

    NASA Astrophysics Data System (ADS)

    Evans, David S.

    1987-06-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries.

  6. Auroral particles

    NASA Technical Reports Server (NTRS)

    Evans, David S.

    1987-01-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries.

  7. Office of Disability Employment Policy

    MedlinePlus

    ... First Policy & Data Platform "Who I Am” Public Service Announcement Advisory Committee on Increasing Competitive Integrated Employment for Individuals with Disabilities Policy Development & Technical ...

  8. Particle displacement tracking for PIV

    NASA Technical Reports Server (NTRS)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

  9. Vocational Rehabilitation and Employment program--self-employment. Final rule.

    PubMed

    2010-01-20

    This document amends the vocational rehabilitation and employment regulations of the Department of Veterans Affairs (VA) concerning self-employment for individuals with qualifying disabilities. We are making changes to conform VA's regulations for self-employment programs for veterans, and for servicemembers awaiting discharge, to statutory provisions, including provisions limiting eligibility for certain supplies, equipment, stock, and license fees to individuals with the most severe service-connected disabilities. We are also making related changes in VA's regulations affecting eligibility for such assistance for certain veterans' children with birth defects in self-employment programs. In addition, we are amending our regulations regarding the approval authority for self-employment plans to make certain requirements less restrictive and less burdensome, to remove a vague and overly broad requirement, to make changes to reflect longstanding VA policy, and to make nonsubstantive clarifying changes.

  10. Breastfeeding and employment: an assessment of employer attitudes.

    PubMed

    Libbus, M Kay; Bullock, Linda F C

    2002-08-01

    Both research and anecdotal reports suggest that maternal employment is associated with failure to initiate breastfeeding and early breastfeeding attrition. The objective of this study was to describe the experience with and attitudes toward breastfeeding of a sample of employers in a small Midwestern city in the United States. Based on an analysis of 85 mail-out questionnaires, we found that less than half of the employers had personal experience with breastfeeding. A large percentage of the sample, however, indicated that they would be willing to facilitate women who wished to breastfeed or express milk in the workplace. However, these employers also stated that they saw little value to their business of supporting breastfeeding in the work environment. Thus, enhancement of breastfeeding opportunity in the work environment may come as a result of public and employer education but, more likely, will require some type of directive from official sources.

  11. Emissions of metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs) from Portland cement manufacturing plants: inter-kiln variability and dependence on fuel-types.

    PubMed

    Zemba, Stephen; Ames, Michael; Green, Laura; Botelho, Maria João; Gossman, David; Linkov, Igor; Palma-Oliveira, José

    2011-09-15

    Emissions from Portland cement manufacturing facilities may increase health risks in nearby populations and are thus subject to stringent regulations. Direct testing of pollutant concentrations in exhaust gases provides the best basis for assessing the extent of these risks. However, these tests (i) are often conducted under stressed, rather than typical, operating conditions, (ii) may be limited in number and duration, and (iii) may be influenced by specific fuel-types and attributes of individual kilns. We report here on the results of more than 150 emissions-tests conducted of two kilns at a Portland cement manufacturing plant in Portugal. The tests measured various regulated metals and polychlorinated dibenzo(p)dioxins and furans (PCDD/Fs). Stack-gas concentrations of pollutants were found to be highly variable, with standard deviations on the order of mean values. Emission rates of many pollutants were higher when coal was used as the main kiln fuel (instead of petroleum coke). Use of various supplemental fuels, however, had little effect on stack emissions, and few statistically significant differences were observed when hazardous waste was included in the fuel mix. Significant differences in emissions for some pollutants were observed between the two kilns despite their similar designs and uses of similar fuels. All measured values were found to be within applicable regulatory limits.

  12. Selective encapsulation by Janus particles

    SciTech Connect

    Li, Wei; Ruth, Donovan; Gunton, James D.; Rickman, Jeffrey M.

    2015-06-28

    We employ Monte Carlo simulation to examine encapsulation in a system comprising Janus oblate spheroids and isotropic spheres. More specifically, the impact of variations in temperature, particle size, inter-particle interaction range, and strength is examined for a system in which the spheroids act as the encapsulating agents and the spheres as the encapsulated guests. In this picture, particle interactions are described by a quasi-square-well patch model. This study highlights the environmental adaptation and selectivity of the encapsulation system to changes in temperature and guest particle size, respectively. Moreover, we identify an important range in parameter space where encapsulation is favored, as summarized by an encapsulation map. Finally, we discuss the generalization of our results to systems having a wide range of particle geometries.

  13. Preselection: How Students Prescreen Employers.

    ERIC Educational Resources Information Center

    Reardon, Thomas

    1979-01-01

    College relations personnel can no longer afford to ignore the factors which attract college grads to employers. Top-notch college students may be less impressed by traditional recruiting incentives as they research and prescreen employers. The article reviews the current incentives for average and above-average students. (Author/CMG)

  14. Leading Gainful Employment Metric Reporting

    ERIC Educational Resources Information Center

    Powers, Kristina; MacPherson, Derek

    2016-01-01

    This chapter will address the importance of intercampus involvement in reporting of gainful employment student-level data that will be used in the calculation of gainful employment metrics by the U.S. Department of Education. The authors will discuss why building relationships within the institution is critical for effective gainful employment…

  15. Employer Demands from Business Graduates

    ERIC Educational Resources Information Center

    McMurray, Stephen; Dutton, Matthew; McQuaid, Ronald; Richard, Alec

    2016-01-01

    Purpose: The purpose of this paper is to report on research carried out with employers to determine demand for business and management skills in the Scottish workforce. Design/methodology/approach: The research used a questionnaire in which employers were interviewed (either telephone or face to face), completed themselves and returned by e-mail,…

  16. Survey of Auto Mechanic Employers.

    ERIC Educational Resources Information Center

    Page, Charles; Scott, David C.

    In order to build auto mechanics curricula and instructional programs responsive to the needs of employers, Bakersfield College (BC) sent a questionnaire to all employers listed under "Automobile Repairing and Services" in the yellow pages of the local telephone book. Only 43 (20 percent) of the 215 questionnaires sent out were returned;…

  17. Employment Survey 1976. AIP Report.

    ERIC Educational Resources Information Center

    Ellis, Susanne D.

    This document presents the summary results of the 1976 employment survey of physics and astronomy graduates of the class of 1975-76 as conducted by the American Institute of Physics (AIP). Data presented include employment status 6-18 months after graduation; background characteristics of doctoral, master's and bachelor's level physicists; time…

  18. Employment Survey 1980. AIP Report.

    ERIC Educational Resources Information Center

    Ellis, Susanne D.

    The employment status of 1980 degree recipients in physics and astronomy was surveyed. For physics degree recipients, the majority of bachelors and masters required two months or less to accept suitable employment, while the majority of doctoral graduates required three months or longer. Information is presented on changes in occupational status…

  19. Employability: Review and Research Prospects

    ERIC Educational Resources Information Center

    Guilbert, Laure; Bernaud, Jean-Luc; Gouvernet, Brice; Rossier, Jérôme

    2016-01-01

    Professional transition, employment, and reemployment are major concerns for nations facing adverse economic situations. The employability construct represents a scientific challenge in order to better understand the relationship between the job seekers' issues and the expectations of the world of work. This paper presents a review of the concept…

  20. Employability Skills. At a Glance

    ERIC Educational Resources Information Center

    Wibrow, Bridget

    2011-01-01

    In a competitive workforce it is not just having the right qualification or technical skills that will land an individual a job; it could very well be their interpersonal skills. How someone communicates is often the first impression an employer has of a possible worker. Yet, it is precisely communication skills that employers feel applicants are…

  1. Employability and Finnish University Graduates

    ERIC Educational Resources Information Center

    Puhakka, Antero; Rautopuro, Juhani; Tuominen, Visa

    2010-01-01

    In this article the authors concentrate on the change in the concept of employability during the Bologna process. They show that employability has gradually moved from a peripheral to a core presence in the most recent Bologna process documents. Using a Finnish university merger (University of Eastern Finland) as an example, the authors…

  2. Employment and People with Disabilities.

    ERIC Educational Resources Information Center

    Nathanson, Jeanne H., Ed.

    1990-01-01

    This newsletter issue offers six articles on employment of people with disabilities. "Employment and People with Disabilities: Challenges for the Nineties" (Frank Bowe) discusses the Americans with Disabilities Act, issues in unemployment and under-education, earnings, and implications for the Office of Special Education and Rehabilitative…

  3. Employer Evaluation of Occupational Programs.

    ERIC Educational Resources Information Center

    Willett, Lynn H.; Piland, William E.

    In an effort to meet the need for a more comprehensive program evaluation, staff at Moraine Valley Community College developed a questionnaire and interview schedule to obtain feedback from employers concerning career programs. Questionnaires were sent to all employers who hired graduates of occupational programs between 1969-71; over 80% returned…

  4. Preferential Remedies for Employment Discrimination

    ERIC Educational Resources Information Center

    Edwards, Harry T.; Zaretsky, Barry L.

    1975-01-01

    An overview of the problem of preferential remedies to achieve equal employment opportunities for women and minority groups. Contends that "color blindness" will not end discrimination but that some form of "color conscious" affirmative action program must be employed. Temporary preferential treatment is justified, according to…

  5. Employment Obtaining and Business Starting

    ERIC Educational Resources Information Center

    Lan, Jian

    2009-01-01

    The implementation of business starting education in higher vocational colleges is of important and realistic meanings for cultivating advanced technology application-type talents and for releasing the employment obtaining pressure of higher vocational students. Based on the analysis on the employment situation of higher vocational graduates, this…

  6. Employment Discrimination in Higher Education.

    ERIC Educational Resources Information Center

    Hustoles, Thomas P.; Griffin, Oren R.

    2000-01-01

    Reviews court decisions related to employment discrimination in higher education. The most significant development was a series of cases affirming that Eleventh Amendment immunity from private money damage claims brought pursuant to various federal employment discrimination statutes applied to state colleges and universities. (SLD)

  7. Maternal Employment and Adolescent Development.

    ERIC Educational Resources Information Center

    Montemayor, Raymond; Clayton, Mark D.

    1983-01-01

    The relationship between maternal employment and adolescent development is enormously complex, and no simple generalizations are possible. Many intervening variables alter the impact that maternal employment has on adolescent development. There is an urgent need to discover what impact this arrangement has on adolescent development. (CJ)

  8. Consumer Leadership in Supported Employment.

    ERIC Educational Resources Information Center

    Inge, Katherine J., Ed.

    1992-01-01

    This newsletter issue provides rehabilitation professionals with various information pieces concerning consumer leadership in supported employment of people with disabilities. First, a chart lists five questions concerning self advocacy and supported employment, and provides consumer responses to the questions. A second item describes…

  9. Employment Survey 1984. AIP Report.

    ERIC Educational Resources Information Center

    Ellis, Susanne D.

    The employment status of 1984-1985 degree recipients in physics and astronomy was surveyed. Information is presented on changes in occupational status of physics and astronomy degree recipients between summer of 1984 and the following winter. The characteristics of graduates of both fields who were employed full-time or undertaking postdoctoral…

  10. Special Issue on Casual Employment.

    ERIC Educational Resources Information Center

    Australian Bulletin of Labour, 2001

    2001-01-01

    Includes "Editor's Introduction" (Cully); "A New Estimate of Casual Employment?" (Campbell, Burgess); "A New Estimate of Casual Employment?: Reply" (Murtough, Waite); "The 'Long-term or Permanent Casual'--An Oxymoron or 'A Well Enough Understood Australianism' in the Law?" (Owens); and "The ACTU's…

  11. Narrowband magnetic particle imaging.

    PubMed

    Goodwill, Patrick W; Scott, Greig C; Stang, Pascal P; Conolly, Steven M

    2009-08-01

    The magnetic particle imaging (MPI) method directly images the magnetization of super-paramagnetic iron oxide (SPIO) nanoparticles, which are contrast agents commonly used in magnetic resonance imaging (MRI). MPI, as originally envisioned, requires a high-bandwidth receiver coil and preamplifier, which are difficult to optimally noise match. This paper introduces Narrowband MPI, which dramatically reduces bandwidth requirements and increases the signal-to-noise ratio for a fixed specific absorption rate. We employ a two-tone excitation (called intermodulation) that can be tailored for a high-Q, narrowband receiver coil. We then demonstrate a new MPI instrument capable of full 3-D tomographic imaging of SPIO particles by imaging acrylic and tissue phantoms.

  12. Particle Sizer

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Microspheres are tiny plastic beads that represent the first commercial products manufactured in orbit. An example of how they are used is a new aerodynamic particle sizer designated APS 33B produced by TSI Incorporated. TSI purchased the microspheres from the National Bureau of Standards which certified their exact size and the company uses them in calibration of the APS 33B* instrument, latest in a line of TSI systems for generating counting and weighing minute particles of submicron size. Instruments are used for evaluating air pollution control devices, quantifying environments, meteorological research, testing filters, inhalation, toxicology and other areas where generation or analysis of small airborne particles is required. * The APS 33B is no longer being manufactured. An improved version, APS 3320, is now being manufactured. 2/28/97

  13. Carbon particles

    DOEpatents

    Hunt, Arlon J.

    1984-01-01

    A method and apparatus whereby small carbon particles are made by pyrolysis of a mixture of acetylene carried in argon. The mixture is injected through a nozzle into a heated tube. A small amount of air is added to the mixture. In order to prevent carbon build-up at the nozzle, the nozzle tip is externally cooled. The tube is also elongated sufficiently to assure efficient pyrolysis at the desired flow rates. A key feature of the method is that the acetylene and argon, for example, are premixed in a dilute ratio, and such mixture is injected while cool to minimize the agglomeration of the particles, which produces carbon particles with desired optical properties for use as a solar radiant heat absorber.

  14. Employment.

    ERIC Educational Resources Information Center

    Witter, William D.; And Others

    1986-01-01

    Beginning with a conceptual introduction which covers the topics of work in the United States, why people work, the labor force, labor markets, unemployment, and work and the young, this document goes on to offer four instructional units for preschool through sixth grade students. The preschool and kindergarten unit called "Earning More than…

  15. Equal Employment Law and the Employer--An Overview.

    ERIC Educational Resources Information Center

    Levins, Will

    1979-01-01

    Sets forth in simple terms some of the requirements of the Equal Employment Opportunities Act of 1972. Available from the New York State Bar Association, One Elk Street, Albany, N.Y. 12207; sc $2.00. (Author/IRT)

  16. Particle Geophysics

    NASA Astrophysics Data System (ADS)

    Tanaka, Hiroyuki K. M.

    2014-05-01

    Geophysics research has long been dominated by classical mechanics, largely disregarding the potential of particle physics to augment existing techniques. The purpose of this article is to review recent progress in probing Earth's interior with muons and neutrinos. Existing results for various volcanological targets are reviewed. Geoneutrinos are also highlighted as examples in which the neutrino probes elucidate the composition of Earth's deep interior. Particle geophysics has the potential to serve as a useful paradigm to transform our understanding of Earth as dramatically as the X-ray transformed our understanding of medicine and the body.

  17. Toward the Employability-Link Model: Current Employment Transition to Future Employment Perspectives

    ERIC Educational Resources Information Center

    Thijssen, Johannes G. L.; Van der Heijden, Beatrice I. J. M.; Rocco, Tonette S.

    2008-01-01

    This article goes into a critical analysis of the concept of employability, its development across historical periods, its components, and different strategic approaches to enhance workers' employability throughout their career. Given the need for a systematic analysis and more empirical research in the field, the authors come up with the…

  18. Particle blender

    DOEpatents

    Willey, Melvin G.

    1981-01-01

    An infinite blender that achieves a homogeneous mixture of fuel microspheres is provided. Blending is accomplished by directing respective groups of desired particles onto the apex of a stationary coaxial cone. The particles progress downward over the cone surface and deposit in a space at the base of the cone that is described by a flexible band provided with a wide portion traversing and in continuous contact with the circumference of the cone base and extending upwardly therefrom. The band, being attached to the cone at a narrow inner end thereof, causes the cone to rotate on its arbor when the band is subsequently pulled onto a take-up spool. As a point at the end of the wide portion of the band passes the point where it is tangent to the cone, the blended particles are released into a delivery tube leading directly into a mold, and a plate mounted on the lower portion of the cone and positioned between the end of the wide portion of the band and the cone assures release of the particles only at the tangent point.

  19. Airborne Particles.

    ERIC Educational Resources Information Center

    Ojala, Carl F.; Ojala, Eric J.

    1987-01-01

    Describes an activity in which students collect airborne particles using a common vacuum cleaner. Suggests ways for the students to convert their data into information related to air pollution and human health. Urges consideration of weather patterns when analyzing the results of the investigation. (TW)

  20. PARTICLE ACCELERATOR

    DOEpatents

    Teng, L.C.

    1960-01-19

    ABS>A combination of two accelerators, a cyclotron and a ring-shaped accelerator which has a portion disposed tangentially to the cyclotron, is described. Means are provided to transfer particles from the cyclotron to the ring accelerator including a magnetic deflector within the cyclotron, a magnetic shield between the ring accelerator and the cyclotron, and a magnetic inflector within the ring accelerator.