Computational Investigation on Effect of Impeller Dimension on Fluid Flow and Interface Behavior for Kanbara Reactor Hot Metal Treatment

Kanbara Reactor (KR) is widely used for hot metal desulfurization pretreatment in the steelmaking industry. The configuration of its impeller plays a crucial role in the reactor performance, but its function is not fully understood. Herein, a 3D volume of fluid (VOF) model coupled with the sliding mesh technique is developed, and the performance of five impellers with different dimensions is investigated. After the test of grid dependency, the calibration of turbulent models, and the validation via experiments, the numerical model is applied to study the typical developing phenomena and the effect of impeller dimension on the fluid flow characteristics, mixing time, interface profile, and vortex core depth. The results show that the centrifugal discharging flow extruded by the rotating impeller creates a double‐recirculation flow pattern in the axial direction. When the aspect ratio χ of the impeller increases, the upper recirculating region is successively strengthened and enlarged. Furthermore, the mixing time as a function of impeller configuration exists a minimum value. Impeller III is the optimal configuration in the current study. In addition, the relationship between vortex core depth and χ is obtained, and the velocity of the gas–liquid interface increases with the increase in χ.