Study on the Multiphase Flow During Top‐Bottom Combined Blowing BOF Steelmaking Process

To investigate the multiphase flow (oxygen–steel–slag–argon) and splashing phenomena within a 210‐ton converter operated under top–bottom combined blowing conditions, a three‐dimensional numerical simulation model was established. This simulation integrated the Realizable k ‐ ε model, the volume of fluid model, and the discrete phase model. The molten steel was not exposed to the oxygen when the top‐blown oxygen flow rate was 40 000 m 3 /h, and the oxygen jet directly contacted the molten steel at top‐blown gas flow rates of 44 000 and 48 000 m 3 /h. The maximum jet speed increased from 17.21 to 163.04 m/s as the top‐blown gas flow rate increased from 40 000 to 48 000 m 3 /h. Meanwhile, the deflection angle of the oxygen jet first increased and then decreased. A positive correlation was observed between the jet speed and the blowing number. The maximum blowing number increased from 0.52 to 19.82 as the oxygen jet flow rate increased from 40 000 to 48 000 m 3 /h. The empirical formula for cavity depth containing two layers of fluid was obtained.