Alfred N. Montestruc

Rotary kiln incineration ― combustion chamber dynamics

Abstract A multifaceted experimental and theoretical program aimed at understanding rotary kiln performance is underway. The overall program involves university, industry, and government participation and is broken into distinct sub-programs. This paper discusses in some detail the research effort performed to date in two of the sub-programs: full-scale in situ sampling and kiln-simulator experimentation. Full-scale in situ measurements are obtained from the Louisiana Division rotary kiln facility of Dow Chemical USA, located in Plaquemine, Louisiana. Summary results obtained from controlled experiments that were performed during continuous processing of carbon tetrachloride and preliminary results obtained during batch mode processing of toluene-laden sorbent packs are presented. Kiln-simulator data are obtained by using the facilities of the Chemical Engineering Department at the University of Utah. Recent kiln-simulator work, conducted in support of the full-scale measurements sub-program, has aided in providing an understanding of the results that have been obtained at the full-scale. Modeling efforts, conducted at Louisiana State University and the University of Utah, have concentrated on the development of realistic, fluid-flow and heat-transfer models, near-term chlorinated kinetic models and bed mass-transfer models to be incorporated into a global three-dimensional kiln-simulator model. The paper concludes with an overview of these modeling efforts.

DYNAMICS OF ROTARY KILN INCINERATION OF TOLUENE/SORBENT PACKS

Abstract The dynamic response of an industrial incinerator to the batch loading of single plastic packs loaded with a toluene/sorbent mixture is reported. Specifically, stable species concentrations and temperature are reported as a function of time for the upper half of the exit region of a rotary kiln, and the exit of the afterburner. Volatile organic sampling train (VOST) samples and continuous measurements of O2, and CO at the stack are also reported. Inconjuction with video tape recordings of the phenomena occurring in the kiln during the processing of each pack, the data provide a much clearer picture than heretofore possible of the conditions that exist in an industrial incinerator. A number of observations are notable. The existence of intermittent releases of hydrocarbon from the processing of each pack has been confirmed. Attendant to these excursions is the production of large quantities of soot in the bottom half of the kiln and the formation of significant vertical gradients in temperature an...

Rotary Kiln Incineration III. An Indepth Study—Kiln Exit/Afterburner/Stack Train and Kiln Exit Pattern Factor Measurements During Liquid CCl4 Processing

Temperature and stable species concentration data are presented from various locations within a full-scale rotary kiln incinerator firing natural gas/carbon tetrachloride/air. The data are being collected as part of a cooperative program involving university, industry and government participation. The overall goal of the program is to develop a more sophisticated understanding of and a predictive capability for rotary kiln and afterburner performance as influenced by basic design and operational parameters. Non-uniformities in stable species and temperature exist for this particular kiln, at the kiln exit, under certain operating conditions. Flow perturbations from within the kiln were found to persist into the afterburner, but not into the stack. High destruction and removal efficiencies (DRE’s) were achieved under the operating conditions of these tests through adequate secondary combustion processing.

Rotary Kiln Incineration of Dichloromethane and Xylene: A Comparison of Incinerability Characteristics Under Various Operating Conditions

Comparisons are made, for the first time, between the combustion characteristics of dichloromethane and xylene in an industrial rotary kiln incinerator. The comparisons are made under different operating conditions, including variable kiln rotation rate and operation both with and without turbulence air. Continuous gas composition and temperature measurements and batch gas composition measurements were obtained from two vertical locations hear the exit region of the rotary kiln. The measurements show that there is significant vertical stratification at the exit of the kiln. Addition of turbulence air enhanced combustion conditions throughout the kiln during xylene processing. During dichloromethane processing, however, the addition of turbulence air had minimal effect and only promoted greater bulk mixing; chlorinated compounds transported from the lower kiln during operation with turbulence air were not efficiently processed in the upper kiln. Evolution of test liquids from the bed was not constant but r...

Field-scale rotary kiln incineration of batch loaded toluene/sorbent. I: Data analysis and bed motion considerations

Abstract In this study, a field-scale rotary kiln incinerator was used for experiments on the processing of toluene contaminated sorbent contained in plastic pa

Rotary Kiln Incineration IV. An Indepth Study— Kiln Exit, Transition and Afterburner Sampling During Liquid CCl4 Processing

Detailed temperature and stable species concentration data are presented from the kiln exit, transition section and afterburner of a full-scale incinerator facility firing natural gas/carbon tetrachloride/air. The data are collected as part of a cooperative program involving university, industry and government participation. The overall goal of the program is to develop an understanding and predictive capability for rotary kiln and afterburner performance as influenced by basic design and operational parameters. The data demonstrate that nonuniformities in stable species and temperature exist, under certain operating conditions, at the kiln exit in the vertical direction only. Measurements from the transition section indicate that non-uniformities may exist within this region under certain operating conditions. Flow perturbations from within the kiln can persist into the afterburner, although the degree of nonuniformity is substantially reduced compared to either the kiln or transition sections. High dest...

Estimating dichloromethane evolution rates from a sorbent bed in a field-scale rotary kiln incinerator

Estimates of dichloromethane evolution rates from the bed of a field-scale rotary kiln are provided during several modes of operation. The calculations of evolution rates are based on stoichiometry and combustion measurements; assumptions that are necessary due to practical limitations imposed on the experiments are discusscd in detail in the paper. A sensitivity analysis of the calculation procedure is also discussed. Mass closures have been shown to range from 65 to 110% depending on the operating condition. Given the uncertainties associated with field-scale testing, these closures are quite remarkable

Rotary Kiln Injection I. An Indepth Study—Liquid Injection

A multlfaceted experimental and theoretical program directed toward the understanding of rotary kiln performance is underway. University, Industry and government participation is involved. This paper, the first In a series, presents a general discussion of the overall programmatic goals, followed by a brief description of the sub-programs Including: in-situ measurements from an industrial-scale rotary kiln located at the Louisiana Division of Dow Chemical USA in Plaquemine, Louisiana; laboratory-scale desorption characterization and klln-slmulator studies; and incinerator modeling efforts. Water-cooled probes have been used to obtain gas samples from the kiln and the afterburner of an Industrial-scale facility. The samples were analyzed using GC and GC/MS techniques. We include in this communication a report on these preliminary measurements.

Fire-endurance tests of dual-wall fiberglass-resin composite pipe

A new method for characterizing fire resistance of composite dual-wall pipes is reported. The technique involves testing a bench-scale pipe sample by exposure to a flame. Detailed temperature profiles and history are obtained. By using this methodology, we have studied the fire resistance of several dual-wall pipe samples. In particular, we have examined the effects of insulation thickness and the use of an intumescent coating. Results show that both insulation thickness and intumescent coating are effective in improving fire resistance.

In Situ Velocity Measurements from an Industrial Rotary Kiln Incinerator

Abstract For the first time, velocities were measured inside a fieldscale rotary kiln incinerator. Combustion gas velocities and temperatures were measured at multiple points across a quadrant of the kiln near its exit using a bidirectional pressure probe and suction pyrometer. To accommodate the new bidirectional probe and gain access to the upper portion of the kiln, a lighter and stiffer positioning boom was designed. The kiln was directly fired using natural gas in a steady state mode. Results indicate strong vertical stratification of both velocity and temperature, with the highest values corresponding to the top of the kiln. Access restraints prevented the lower region of the kiln from being mapped. Horizontal variations in both temperature and velocity were insignificant. Operating conditions were varied by adjusting the amount of ambient air added to the front of the kiln. Increasing the flow of ambient air into the front of the kiln reduced the measured temperatures as expected, but did hot have ...