Compact Waste Incinerator Based on Vortex Combustion

• Published in: Combustion science and technology 1996-12, Vol.121 (1-6), p.333-349
• Main Authors: GUTMARK, E. J., PARR, T. P., WILSON, K. J., YU, K. H., SMITH, R. A., HANSON-PARR, D. M., SCHADOW, K. C.
• Format: Article
• Language: English
• Subjects: Applied sciences; Combustion of heterogeneous mixtures. Incineration; Combustion. Flame; DRE; Energy; Energy. Thermal use of fuels; Exact sciences and technology; liquid benzene; Theoretical studies. Data and constants. Metering; Vortex; waste surrogate
• ISSN: 0010-2202; 1563-521X
• DOI: 10.1080/00102209608935602

Active control of fluid dynamics has been used to enhance mixing in incinerator afterburner experiments in order to increase the DRE of a waste surrogate. Experiments were conducted in two stages: a detailed study of the concept of utilizing vortex combustion for incineration in a small scale flame burning gaseous fuel and an extension to a more practical system using liquid fuel with significantly higher heat release. The open loop active control system is based on the concept of combustion in periodic axisymmetric vortices. Acoustic excitation is used to stabilize coherent vortices in the air flow. Acoustic excitation and automotive fuel injectors, were used to control gaseous or liquid fuel injection, respectively, such that the fuel is introduced into the air vortices at the right time during their formation. It is shown that this control methodology leads lo improved waste destruction. A gaseous fueled actively controlled 4.5 kW incinerator was able to surpass 99.997% DRE (destruction and removal efficiency) even when the waste surrogate (gaseous benzene) constituted 66% of the total fuel content. Parameters found critical to maintenance of high DRE in the gaseous fuel/waste tests were the fraction of circumferentially entrained air and the phasing angle of fuel injection with respect to the air vortex roll-up. The control methodologies studied using gaseous fuel and waste were extended to liquid afterburner/incinerator of 56 kW energy release. The DRE for liquid benzene exceeded 99.999% in this system when combustible to air ratio was kept below 0.91. Again, the use of synchronous fuel injection into coherent air vortices was found to be critical to maintaining high DRE. Even more crucial was good atomization of the liquid fuel/waste mixture.