Fluid Dynamics Analysis of Gas Jet with Particles

We conducted a three-dimensional fluid dynamics analysis of the solid-gas mixed-phase flow from a top blowing lance by considering the application of powder top blowing to hot metal dephosphorization in the steelmaking process. When a mixed-phase flow of gas and powder passed through a single-nozzle lance, the powder particles passed unevenly near the central axis of the nozzle and the gas flowed around the powder particles in a circular pattern. Thus, the maximum gas velocity shifted in the radial direction from the central axis of the nozzle. After the outlet of the single-nozzle lance, the gas velocity on the central axis increased and the maximum gas velocity shifted to the central axis. The velocity of the powder immediately after being discharged from the nozzle outlet was lower than the gas velocity but then gradually increased, while the gas velocity decreased. The position where the velocity of the powder, which has a greater inertial force, started to decrease was farther from the nozzle outlet than that for the gas velocity. When a multiple-nozzle lance with an angle of inclination is used, the powder particles may impinge on the nozzle inner wall. Thus, it is necessary to consider the wear of the nozzle inner wall and the dispersion region of the powder particles.