Effect of Instability of Cavity Induced by Top Blowing Gas Jet on Spitting Behavior

Abstract

　　　In steelmaking process, oxygen gas supplied into molten iron could induce spitting phenomena which raise problems such as low yield ratio and deposition inside the vessel. However, the effect of operating condition on spitting is not clarified. In the present paper, channel-type recirculating water bath and top blowing of compressed air are used to clarify the effect of cavity shape on spitting rate. Primary cavity size including depth and width changes periodically. and secondary cavity is observed inside the primary cavity. The formation rate of secondary cavity decreases at upstream side and increases at downstream side with the increase of recirculating rate. Time-average cavity shape could not explain the spitting rate. However, the formation rate of secondary cavity correlates well with spitting rate.