A CFD-PBM Coupled Model Predicting Anodic Bubble Size Distribution in Aluminum Reduction Cells

Abstract

In order to understand more details of anodic bubble formation, coalescence and movement mechanism under the horizontal anode bottom, a population balance model (PBM) was used to calculate the anodic bubble size distribution (BSD) in aluminum reduction cells. The proposed PBM was numerically solved with a class method (CM) which has been provided in ANSYS FLUENT. A CFD-PBM coupled model that combines the PBM and CFD model was used to simulate more complex flow behavior with proper coalescence and breakage mechanism of anodic bubble. A modified k-e turbulence model was used to describe liquid phase turbulence in the simulation. The effects of current density, anode width and the presence of slots on the BSD have been investigated. In addition, the relative influence of the bath flow induced by the cell magneto-hydrodynamic (MHD) on the BSD is also discussed. The predicted BSD is in accordance with a series of literature experimental results.