United States Environmental Protection Agency Air and Energy Engineering Research Laboratory Research Triangle Park, NC 27711 Research and Development EPA/600/SR-94/060 May 1994 EPA Project Summary Application of Pulse Combustion to Incineration of Liquid Hazardous Waste Carin DeBenedictis The report gives results of a study to determine the effect of acoustic pulsa- tions on the steady-state operation of a pulse combustor burning liquid hazard- ous waste. A horizontal tunnel furnace was retrofitted with a liquid injection pulse combustor. The pulse combustor burned No. 2 fuel oil that was doped with principal organic hazardous con- stituents (POHCs). The POHCs that were used were carbon tetrachloride and chlc- robenzene. This Project Summary was developed by EPA's Air and Energy Engineering Research Laboratory, Research Tri- angle Park, NC, to announce key find- Ings of the research project that Is fully documented in a separate report of the same title (see Project Report ordering information at back). Introduction The purpose of this study was to deter- mine the effect of acoustic pulsations on the steady-state operation of a pulse com- bustor burning liquid hazardous waste. A pilot scale horizontal tunnel furnace was retrofitted with a liquid injection pulse com- bustor supplied by Sonotech, Inc. (Atlanta, GA). The pulse combustor burned No. 2 fuel oil that was doped with principal or- ganic hazardous constituents (POHCs). The POHCs that were used were carbon tetrachloride and chlorobenzene Pulse combustion refers to a combus- tion process that varies periodically. Pulse combustion is a relatively old technology. It was first discovered in 1777 when it was noted that a flame placed in a long vertical tube produced the "singing flame" phenomenon. One of the first applications of a pulse combustor was for the engine that propelled the World War II "buzz bomb." Pulsating combustion occurs when the heat released by a combustion pro- cess spontaneously excites a pressure wave within the combustion chamber. When this pressure wave is in phase with periodic heat release, pressure and gas velocity oscillations occur. In order to ex- cite large amplitude pulsations from a pulse combustor, the frequency at which it oper- ates must equal one of the natural acous- tic modes of the combustion chamber. When these frequencies are matched, resonant pulsations are excited in both the combustion section and the tailpipe portion of the pulse burner. An important benefit of a pulse combustor for hazard- ous waste incineration is the improved mixing of combustion gases. The reso- nant pulsations cause significant gas tur- bulence within the combustion zone. Baseline conditions were tested as well as hazardous waste operations. For each test condition, the burner was operated in both a pulsing and nonpulsing mode. Large amplitude acoustic pulsations were gen- erated by adjusting the burner frequency to match the natural frequency of the com- bustion chamber. Detailed chemical analy- ses of the stack gases were performed, including destruction and removal effi- ciency (ORE) computations, volatile and semivolatile screening analyses, particu- late loading determinations, and a particle size distribution analysis. The results show that steady-state operation of the pulse combustor was not successful in isolating the effect of acoustic pulsations on com- bustion emissions. ORE values were found to be greater than six nines (99.9999%) for both pulsing and nonpulsing opera- tions. The pulse combustor for this study was equipped with a fuel vaporization unit that may have enhanced the destruction capabilities of the burner. It is not known if operating without a vaporizer under non- ideal combustion conditions would degrade burner performance. Printed on Recycled Paper ------- The EPA author, Carin DeBenedlctis (also the EPA Project Officer, see below), is with the Air and Energy Engineering Research Laboratory, Research Triangle Park, NC 27711. The complete report, entitled "Application of Pulse Combustion to Incineration of Uquld Hazardous Waste," (Order No. PB94-161262; Cost: $27.00, subject to change) will be available only from: National Technical Information Service 5285 Port Royal Road Springfield, VA 22161 Telephone: 703-487-4650 The EPA Project Officer can be contacted at: Air and Energy Engineering Research Laboratory U.S. Environmental Protection Agency Research Triangle Park, NC 27711 'U.S. Government Printing Office: 1994 — 550-067/80253 United States Environmental Protection Agency Center for Environmental Research Information Cincinnati, OH 45268 Official Business Penalty for Private Use $300 BULK RATE POSTAGE & FEES PAID EPA PERMIT No. G-35 EPA/600/SR-94/060 ------- |