Physical simulation of bottom powder injection in combined blown converter

A cold model of top and bottom blown converter with bottom powder injection was established to investigate the powder distribution and penetration ratio in melt bath. Water, salt-coated hollow alumina particles and vacuum-pump oil were used to simulate liquid steel, limestone powder and slag, respectively. The powder distribution under different bottom blowing arrangements was studied by using the image processing method to find out the optimum bottom tuyere arrangement. With the optimum bottom tuyere arrangement, the effects of solid/gas ratio and powder particle size on powder penetration ratio were studied. The results show that the powder penetration ratio increases with the increase of solid/gas ratio and powder particle size. Under the laboratory conditions, the solid/gas ratio of 30~40 and the powder particle size 0.212~0.380 mm are suggested.