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Show The University of Dayton Research Institute (UDRI) has investigated the destruction of hazardous materials in combustion environments3 • Based on their data, a minimum afterburner temperature of 1650°F and a gas residence time of 1 second would be required to maximize the destruction of the organic compounds leaving the kiln. These values assume that the afterburner has a uniform temperature and is perfectly mixed. Since a practical afterburner may have temperature variations and will not be perfectly mixed, Higher temperatures and longer residence times may actually be required to ensure that these minimum conditions are achieved by all of the material leaving an actual incinerator. As predicted in the pre-test modeling, metals enrichment in the exhaust increased with temperature. The volatility of the metal plays a key role in determining its behavior. The fraction of the input metal found in the exhaust gas stream in the treatability tests can be calculated. These numbers can be used directly to estimate the partitioning which will occur in the full-scale kiln. The data can then be used in the design and selection of appropriate flue gas cleaning equipment. SUMMARY The factors which influence the emission of toxic compounds from a rotary kiln incinerator were examined. An approach combining theoretical modeling and bench-scale treatability studies was used. The kiln temperature was found to be of primary importance. Increased temperatures increased the rate of destruction of organic compounds and increased the quantity of metals leaving the kiln. The tests indicated that kiln temperatures as low as l0000P would be sufficient to remove all the organic compound from the solids in 1 hour. The behavior of most metals was strongly influenced by kiln temperature. REFERENCES 1. Barton, R.G., Clark, W. D., and Seeker, W. R. Fate of Metals in Waste Combustion Systems. First Congress on Toxic By-Products o/Combustion, Los Angeles, CA. Accepted for Publication: Combustion Science and Technology. 2. Quann, R. J., and Sarofim, A. F. (1982). Vaporization of Refractory Oxides during Pulverized Coal Combustion. 19th Symposium (International) on Combustion. The Combustion Institute, 1429. 3. Dellinger, B., Jorres, 1. L., Rubey, W. A., Hall, D. L., Graham, 1. L., and Carnes, R. A. (1988). Incinerating Hazardous Wastes. ed. H. M. Freeman, Technomic Publishing Co., Lancaster. -19- |