The use of vortex method in the analysis of multiphase flow in aluminum reduction cells

Abstract

As the principal character of flow pattern, the vortex distribution plays a dominant role in the flow behavior of aluminum reduction cells, thereby affecting the cell performance. Based on the commercial CFD software CFX12, the method of vorticity and swirling strength was introduced to analyze vortex structures of the bath and metal phases quantificationally in a 300 kA cell, in which both the influences of electromagnetic forces (EMFs) and gas bubbles were included. Research results prove that, compared with velocity vector distribution and streamline picture, it can provide more flow field information with the above method, which may help to the optimization of alumina feeding points configuration. Vortexes usually occur as reverse symmetrical pairs. The single factor comparative study shows that the EMFs tend to trigger large vortexes near the upstream side, while gas bubbles mainly stir the bath and generate small ones around anodes.