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Show Development of RH-Multi-Function-Burner K. Fukuda, [Shima, Y.Hoshijima,H. Yamamoto, K.Onuki Nippon Steel Corporation, Hirohata Works Fuji-cho 1 ban, Hirohata-ku, Himeji-city, Hyogo-pre, Japan Abstract In order to achieve the ideal RH process with high decarburization, accurate temperature control of molten steel and non-skull operation, we developed the "RH-Multi-Function-Burner" {RH-MFB for short). By RH-MFB, (l)the free oxygen in molten steel can be easily controlled to the desirable level so that high decarburization is obtained for even high carbon content at the initial state of the treatment, (2)the temperature of molten steel can be heated with aluminum reheating, (3)the surface temperature of the refractory can be kept high enough so that splashed steel during treatment is not attached to the wall, and also the temperature drop of molten steel during treatment can be restrained. · RH-MFB is a water-cooled lance with one outlet through which both oxygen and fuel flow out from the top of the vessel. And it can be set at any desirable height in the RH snorkel for the purpose of using it by moving it from top to botto~ bot tom to toP. - RH-MFB has stable flame under atomospheric pressure and vacuu~ high efficiency in heating both molten steel and refractory and also high efficiency in adding oxygen to molten steel. RH-MFB provides a skull-less operation free from contamination so that we can produce various steels of different chemical compositions with even one vessel at a high rate of production. Lis t E Hat Href Hin V. Vo X d of symbols effective heat efficiency heat input to molten steel heat input to refractory · total heat input by burner burning gas blowing index{estimated gas velocity on the center of stream at the distance of X from nozzle outlet) average gas velocity at nozzle outlet distance from nozzle outlet diameter of nozzle outlet kc decarburization rate constant [Clt final composition of [C] in molten steel [C]i initial composition of [C] in molten steel t treatment time 1 |