Numerical simulation of gas and liquid flow in steelmaking converter with top and bottom combined blowing

By combining a volume of fluid (VOF) and discrete phase model (DPM) multiphase flow models, a mathematical model is established to describe the gas and liquid two phase flow in a steelmaking converter with top and bottom combined blowing. The effect of the numbers and location of the bottom tuyeres and top lance height on the gas and liquid two phase flow are investigated and the prediction is validated by the reported actual measured results. The results show that the stirring energy of the combined blowing converter is mainly from buoyancy driven bottom blowing bubbles and the bottom tuyere arrangements have a significant impact on the bubbly plume of combined converter. The mixing efficiency using three bottom tuyeres is higher than the cases with two or four bottom tuyeres and the optimum placement for the bottom tuyeres is away from the centre of the bottom on 0.3D-0.4D (D is the diameter of converter bottom). The mixing time increases with the angle theta decreasing, which is between bottom tuyeres and trunnion, and 45 degrees is suggested for the angle theta. The top lance height has little influence on the mixing efficiency for the combined blowing converter.