Abstract: A mathematical model of the metallurgical reactor with swirling flow driven by gravitational potential energy was established to analyze the flow field and gas volume fraction. The results showed that the modeling results are basically consistent with the experimental results, thereby the reliability of the proposed model and the relevant computation program are verified. The reactor driven by gravitational potential energy can attain better swirling flow effect, and the swirling effect is the best when the vane has the form of forward bending. The gas volume fraction in the mixing tube increases greatly with increasing the curvature radius. When the curvature radius is 150 mm, some bigger bubbles appear in the vane reactor.