Injected gas distribution in oxygen blast furnaces with shaft gas injection

The gas distribution behaviors of oxygen blast furnaces with shaft gas injection were experimentally studied using a two-directional cold model. The effects of total gas flow rate in the shaft, auxiliary tuyere diameter and location, and the ratio of injected gas flow rate to total gas flow rate in the shaft on the injected gas distribution were investigated in detail. The results show that the injected gas distribution in the shaft is almost dominated by the ratio of injected gas flow rate to total gas flow rate in the shaft, while the influences of total flow rate and auxiliary tuyere diameter are little. Meanwhile, the influence of radial eddy diffusion is also little in the process of gas rise in the shaft. According to isoconcentration distribution curves from experimental data, the injected gas distribution in the shaft is divided to two dissimilar zones, a main flow region of injected gas and a main flow region of upward gas. Furthermore, the penetration equation of injected gas at the injection level is deduced through the regression analysis method. In addition, the auxiliary tuyere installed in the lower part of the shaft is advantageous for iron ore indirect reduction in the shaft.