A numerical study about the influence of a bubble wake flow on the removal of inclusions

Abstract

The inclusion removal mechanism due to a bubble wake flow was studied using a water model and a three dimensional numerical model. In the experiments, a high-speed camera was used to record the bubble movement and the inclusion behavior connected to the flow. In the numerical model, the bubble induced fluid dynamics in the liquid was simulated using the volume of fluid (VOF) method. Also, the individual particle motion was tracked by the discrete phase model (DPM). A two-way coupling approach was used to model the interaction between the continuous phase and the discrete particles. The calculated results were compared with the experimental observations in the air-water-particle system. Calculations were also extended to an argon-steel-inclusion steelmaking system. The predictions show that the removal percent per bubble is increased with an increased bubble size. However, the inclusion removal percent per unit bubble volume can be improved by decreasing the bubble size. Also, the inclusion rising zone was found to be 1.625 and 5 times of the bubble size in width and height, respectively. It is also shown that the bigger inclusions are more easily removed compared to the smaller ones.