Back-attack Action of Gas Jets with Submerged Horizontally Blowing and Its Effects on Erosion and Wear of Refractory Lining

摘要

There is all a serious trouble in the metallurgical processes with the submerged gas blowing, that is the excessive erosion and wear of the tuyere (lance with constant cross-sectional area) and the refractory lining near its outlet, no matter what the upward bottom- or horizontally side - blowing is used. The most distinct shortage of the Argon-Oxygen Decarburization (AOD) side - blowing process just is the short life of its refractory lining, and the erosion and wear of the lining demonstrates a very obvious non - uniformity. The "back-attack" aciton of the gas jets is referred to as an important reason to cause the kind of situation like that. Many studies on these had been conducted under the different blowing conditions, in order to attempt to alleviate or suppress and eliminate the back-attack phenomena of the gas jets. The results available now showed that raising the blowing pressure, using the flat-, micro-hole assembling - or spiral - type tuyere, reducing the width of the annular slit (the sub-tuyere) of an annular-tube tuyere and others are all able to decrease the back-attack frequency, to the different extents. Based upon the results of the water modeling study on the horizontally gas side-blowing process, Aoki et al. suggested that the occurrence of the back-attack phenomenon would be brought about from the bubble blowing backward and attacking on the front surface of the tuyere.