Multi-phase Flow Simulations in Direct Iron Ore Smelting Reduction Process

摘要

A mathematical model for the simulation of multi-phase flows in direct iron ore smelting reduction furnaces has been developed in this study. This model was used to investigate the effects of gas flow rate and the number of bottom-blown gas tuyere on the flow patterns in the smelting vessel. With an increase in gas flow rate, the flow field becomes larger, the agitation of the liquid surface and the slag becomes more violent, and the depth to which the slag is drawn increases. The flow field and the slag of the centre section are distributed asymmetrically in the 3 tuyere case. In the 4 tuyere case, some slag is contained in a low-velocity region in the center of the liquid. In the 5 tuyere case, the flow field and the agitation of the slag is more violent than in the 3 and 4 tuyere cases. Under the same gas flow rate, as the number of tuyere increases, the flow field becomes bigger. The agitation of the liquid surface also becomes greater and the motion of gas marker particles becomes more violent. The agitation of the slag becomes more violent and the slag reaches greater depths as the number of bottom-blown gas tuyere increases. By using numerical simulation, the mixing of the slag and the liquid steel under different bottom-blown conditions can be predicted. It is very useful to evaluate the effects of designs and operating conditions on the reduction efficiency of iron oxide in slag.