Mixing effect for the bath with bottom regiment arrangements in the steelmaking converter

Abstract

The mixing efficiency of molten metal in a vessel is affected by the bottom blowing intensities and the positions of bottom nozzles. In this article, physical experiments and multiphase flow simulation models were used to investigate the effects that different distributions of bottom regiments have on the internal dynamic conditions of a molten bath. The results reveal that the configuration of the bottom regiments can overcome the drawback that a single blowing gas strand cannot effectively drive the rapid flow of liquid steel. When the outer regiments were kept on the circumference of a circle with a diameter ratio of 0.7 at the bottom of a furnace, the stirring force of blowing bubbles on molten steel was the strongest. Under a gas flowrate of 960 Nm3 · h−1, the minimum mixing time was 38 s, and the minimum proportion of inactive zone was 0.025. Also, from comparing the results of physical experiments and numerical simulations, it was found that the occurrence of coalescence in the bottom blowing gas streams is more beneficial for mixing the bath. Also, the range of the synergy of gas flow streams can be widened by increasing the distance between regiments and the bottom blowing flowrates.