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Show Conclusions The apparent increases in the rates of mass, momentum (i.e., mixing) and heat transfer within the RKIS, due to excitation of high amplitude acoustic pulsations, has a strong tendency to reduce the emissions of soot and/or semi-volatile and non-volatile hydrocarbons. It is not clear whether this is due to an inhibition of the soot formation process or due to an enhancement of the soot/condensable organic destruction process. The addition of pulsations appears to drive the unburned material in the transient puffs towards more oxidized and lower molecular weight species. This results in a net increase in emitted C O and T H C . Although from a mass emission standpoint this does not appear advantageous, from a health effects standpoint, there are significant advantages derived from a reduction in the amount of soot and semi-volatile organics. Many of the respirable carcinogens, such as benzo-a-pyrene, condense on soot particles and are inhaled into the lungs. Due to their small sizes, it is difficult to remove soot particles with commercially available air pollution control devices. Any reduction in soot emissions is advantageous from these perspectives. In addition, C O and T H C species are probably more easily destroyed in a properly designed afterburner system. Experiments performed using different surrogate wastes (toluene and polyethylene) indicate that, in situations where the surrogate waste compound bums extremely rapidly, such as is the case with toluene, the pulsations have less of an effect on total mass emissions than is the case with a slower burning waste such as polyethylene. It appears that the increase in mixing rate produced by the pulsations results in a more effective utilization of available oxygen, when it is available. In the absence of a significant amount of available oxygen, the pulsations serve to reduce soot, but not to reduce other emitted PIC surrogate species. Acknowledgment The research described in this paper was partially supported by an EPA SBIR Phase I grant to Sonotech. Most of the material presented in this paper was originally published in Reference 4, which was coauthored with Dr. P. M . Lemieux and Mr. C. R. Stewart from EPA. References 1. Rabhan, A. B., Daniel, B. R. and Zinn, B. T., "Industrial Pulse Combustor Development", GRI Report No. GRI-87/0350, June 1987. 2. Rabhan, A. B., Dubrov, E., Alvey, D. A., Daniel, B. R. and Zinn, B. T., "Industrial Pulse Combustor Development and Its Application in Spray Dryers and Cement Calciners", GRI- 90/0203, Final Rpt. M a y 1986-Sept. 1990, Gas Research Inst., July 1991. 3. Zinn, B. T., Dubrov, E., Rabhan, A. B. and Daniel, B. R., "Application of Resonant Driving to Increase the Productivity and Thermal Efficiency of Industrial Processes", Proceed, of Int'l. Symposium on Pulsating Combustion, Sponsored by Sandia National Laboratories and the Gas Research Institute, Monterey, California, August 1991. 4. Stewart, C. R., Lemieux, P. M . and Zinn, B. T., "Application of Pulse Combustion to Solid and Hazardous Waste Incineration", Proc. Int. Symp. on Pulse Combustion, Aug. 6-8, 1991, Monterey, California. 5. Plavnik, Z. and Zinn, B. T., "Application of Pulse Combustion in Solid and Hazardous Waste Incineration", Final Report Prepared by Sonotech, Inc. Under E P A Contract No. 68D10101, June 8 1993 6! Linak, W.P., Kilgroe, J.D., McSorley, J.A., Wendt, J.O.L. and Dunn, J.E., O n the Occurrence of Transient Puffs in a Rotary Kiln Incinerator Simulator I. Prototype Solid Plastic Wastes, J. Air Poll. Cont. Assoc, 37, 54. 9 V-28 |