Numerical investigation of sinusoidal pulsating gas intake to intensify gas-slag momentum transfer in the top-blown smelting furnace

The variation characteristics of bubble morphology and the thermal-physical properties of bubble boundary in the top-blown smelting furnace are explored by means of the computational fluid dynamics method. The essential aspects of the fluid phase (e.g. splashing volume, dead zone of copper slag, and gas penetration depth) are explored, together with the effect of sinusoidal pulsating gas intake on the momentum transfer performance between phases. The results illustrate that two relatively larger vortices and two smaller vortices appear in the bubble waist and below the lance, respectively. The larger ones expand and the smaller ones shrink, leading to the contraction of the bubble waist. Compared to the constant velocity condition, the splashing volume and dead zone volume of the slag under the V_g=58+10sin(2πt) condition are reduced by 24.9% and 23.5%, respectively. Gas penetration depth and slag velocity of the latter are 1.03 and 1.31 times higher than those of the former, respectively.