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

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 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

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EPA/600/SR-94/060

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