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Show AFRC90 Paper #9 DEVELOPMENT OF A SLUDGE SLAGGING COMBUSTOR S~~( Takeo Yoshigae, Tomio Suzuki KOBE STEEL, LTD. 3- 18, Wakinohamacho I-chome, Chuo -ku, Kobe Japan ABSTRACT Kobe Steel has developed a sludge slagging combustor (I) • The main features of this combustor are the use of swirling flow combustion and two-stage air injection. Swirling flow combustion increases the combustion intensity, dust collection and retention time. Two-stage air injection produces a desirable flow pattern and temperature distribution. Additional fuel is added in order to keep the wall temperature of the slagging combustor uniform at above one hundred degrees higher than the ash fusion temperature. The sewage ash melts quickly after entering the slagging combustor. The slag capture for ash is over 95%, and the NOx emission is less than 100 ppm corrected to 12% Oz. A heavy metal water-miscible test indicates no problem with slag disposal and a strength test indicates that the slag can be used as a construction material. The sludge slagging combustor has been applied to a 40 ton-cake per day Melting After Carbonizing Slud~e system commercial plant. The expected performance of the slagging combustor is comfirmed by the commercial plant operation. INTRODUCTION The amount of sewage sludge produced increases every year. However, as sewage disposal area is limited, sewage disposal is becoming a serious problem. As a solution to this problem, the sludge slagging combustor has attracted our attention, by which the volume of sewage sludge ash can be decreased to 15% of its original volume, the heavy metal in the ash can be enclosed in the slag, and the slag produced by this method can be used as construction material or for similar applications. In order to investigate this technology, Kobe Steel has developed the sludge slagging combustor. This sladge slagging combustor has been applied to a 40 ton cake per day Melting After Carbonizing Sludge system commercial plant. -1- |