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
Official Business
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EPA
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EPA/600/SR-94/060
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