Oblon, Spivak, McClelland, Maier & Neustadt, P.C.
Direct reduction method and rotary hearth furnace
 In a rotary hearth furnace wherein objects including a mixture of a metal oxide, a reductant such as coal, and the like are fed onto the hearth, the fed objects are heated and reduced through the application of a flame of a burner provided on a ceiling portion or the upper portion of a side wall of the furnace, and the reduced objects are discharged from the furnace so as to be collected. The rotary hearth furnace has an air feeder for feeding air for secondary combustion at a position below the burner and in the vicinity of the hearth of the furnace for the purpose of burning a flammable gas generated from the objects. A flame of this secondary combustion accelerates the heating of the objects. Also, through a combined use of air for secondary combustion and excess air from the burner and an appropriate regulation of the ratio of therebetween, the objects are heated effectively. 
Kabushiki Kaisha Kobe Seiko Sho
F F Y C F F F
F27B F27D Y02P C21B F27B F27B F27B
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Tomio Makoto
Suzuki Nishimura