3D Modeling Study of Bubble-Driven Flow and Its Interaction with Cell Operation.

A detailed three-dimensional model of carbon dioxide generation and movement beneath the anode in an aluminum electrolysis cell has been developed. By incorporation of localized current density and multiple nucleation sites, the model captures the transient behavior of the anode-cathode distance (ACD) and the deformation of the bath-metal interface (BMI) caused by bubble dynamics. It also evaluates the pot's response in terms of turbulent kinetic energy, providing insights into alumina dissolution efficiency and heat transfer mechanisms. The model further investigates how the MHD-induced flow direction and evacuation channel geometries impact bubble behavior, voltage fluctuations, and thermal distribution. The results not only align with existing experimental data but also shed light on subtle interplays within the cell environment. Notably, the orientation of the MHD flow emerges as a decisive factor in the local bubble overvoltage and the heterogeneity of alumina mixing. This study provides industry with actionable insights into optimizing cell design parameters by taking into consideration the impact caused by their operational ACD range, the evacuation channel width, and the relative MHD flow direction.