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Show EXPERIMENTAL STUDY OF AN ENHANCED INFRA-RED METAL FIBER BURNER David W . Lu and David W . Collier Eclipse Combustion 1665 Elmwood Rd. Rockford, IL 61103 A B S T R A CT A natural gas/air premixed metal fiber burner has been developed and studied experimentally. This work is directly related to designing an enhanced infra-red thermal radiant burner with high radiant heat flux, low N O x and C O emissions, and which will overcome the difficulties encountered by the porous ceramic infra-red burner. Since the burner is of metallic construction, it offers greater durability than the existing ceramic fiber burner, while at the same time offering the good thermal characteristics of the ceramic infra-red burner, i.e., uniform surface temperature, intensive radiation emissivity, and high cool-down/heat-up rate, etc. In addition, the burner provided a stable radiation output over a wide range of firing rates. A radiant efficiency of as much as 5 5 % has been achieved. The major emission pollutants, N O x and C O , are below 20 ppm at a wide range of the desired operating conditions. All of these results predict a technique breakthrough in gas firing technology. The burner will be on the market shortly. INTRODUCTION Infra-red gas fired burners with premixed combustion embedded in a permeable mat made of woven or sintered fine metal fiber have received a lot of attention in the past few years. Mechanism and characteristics of premixed combustion have been theoretically and experimentally analyzed by several investigators to achieve a burner with intense radiation capabilities over a wide operating range. To the author's knowledge, a small amount of technical breakthrough has been identified. The existing infra-red burner made of metal fiber is considered to have a relatively narrow operating range, low thermal output and high C O emission. Performance of this burner is limited by the flame position. From this data base, Eclipse started to evaluate an enhanced infra-red metal fiber burner to overcome these difficulties. A successful result has been obtained. The experimental date indicates that the present Eclipse infra-red burner has distinct technical advantages over the existing technology. It has great potential to retrofit the existing gas fired radiant burner because of its l IV-25 |