PASSIVE AND ACTIVE CONTROL OF NOX IN INDUSTRIAL BURNERS

Citation
O. Delabroy et al., PASSIVE AND ACTIVE CONTROL OF NOX IN INDUSTRIAL BURNERS, Experimental thermal and fluid science, 16(1-2), 1998, pp. 64-75
Citations number
39
Categorie Soggetti
Engineering, Mechanical","Phsycs, Fluid & Plasmas",Thermodynamics
ISSN journal
08941777
Volume
16
Issue
1-2
Year of publication
1998
Pages
64 - 75
Database
ISI
SICI code
0894-1777(1998)16:1-2<64:PAACON>2.0.ZU;2-H
Abstract
Industrial burners that use either fuel oil or natural gas are conside red as candidates for implementing strategies for control of NOx. Two burners, at 20 and 800 kW burning fuel oil are installed in a tunnel f urnace and subjected to active control by way of introducing pulses in to the air supply. Using optical diagnostics to identify the CH radica l, the imaging reveals the evolution of the vortical structures within flames: a non-premixed diffusion flame appearing in the braids of the vortex and a premixed core region. Prompt NOx mechanisms are explored , noting that thermal NOx in this case is not the predominant contribu tor in the fuel burner. III the case of natural gas burners, thermal N Ox control is achieved passively. The burners achieve significant redu ctions in NOx by radically altering the fuel-air jet distribution from the normal air-surrounding Fuel ports approach: the air and fuel jets are arranged on a base circle, each low momentum fuel port alternatin g with high momentum air port and each type pointing away from the bur ner axis at a different, but constant, angle. The NOx reduction mechan ism is speculated to be due to flue gas recirculation with concomitant reduction in flame temperature. The burner has been tested in both si ngle and multiple modes in a unique multi-burner furnace. Results obta ined using both active and passive control and manipulation indicate t hat significant enhancement of combustion can be achieved by applying modern tools and new ideas. (C) 1998 Elsevier Science Inc. All rights reserved.