The effect of top lance level and bottom blowing flowrate on mixed time in bath

mouth spraying

penetration depth in steel and liquid surface fluctuation have been studied by 1:8 water modelling of a 85 t top-bottom combined blown converter at Chongqing Steel. The test results showed that maximum stirring energy was obtained as the top lance level was at 50～100 mm and the spraying amount caused by top lance jet penetration was up to maximum as the top lance level was at 90~110 mm.The top-bottom blown parameters for the 85 t converter at Chongqing Steel has been established that in primary phase of melting the top lance level is 1600~1760 mm and the bottom blowing flowrate is 240~350 m³/h; in second phase both parameters are 1100~1300 mm and 160~200 m³/h respectively; and in later phase both are 1040 ~ 1120 mm and 200～350 m³/h.