Effect of Gas Bottom Blowing Conditions on Fluid Flow Phenomena and Mixing Time of Molten Iron inside an Ironmaking Smelter

Abstract

This study uses a water model experiment to investigate the effects of gas bottom blowing conditions on fluid flow phenomena and the mixing time of molten iron within an ironmaking smelter. Our experimental setup adopted four tuyeres in a square-corner placement. The parameters for trials include bottom-blowing tuyere size (7.5∼15.0 mm) and the bottom blowing gas flow rate (320∼480 NL/min). Experimental results show that the bubble size decreased and the invading depth became deeper as the tuyere size decreased and the total gas flow rate increased. Consequently, the spout height of the liquid surface became higher. The results of the mixing experiment indicate that under any bottom blowing gas flow rates, the 10.0 mm tuyere has the shortest mixing time. Except for the 7.5 mm tuyere, the 10.0 mm, 12.5 mm, and 15.0 mm tuyeres had shorter mixing times and better mixing effects as the gas flow rate increased. Therefore, the best combination for mixing iron phase in a smelter is to use a 10.0 mm tuyere and a gas flow rate of 480 NL/min, which has the appropriate intensity of the total blown energy and the degree of stirred liquid bath.