Theoretical Investigation of the Inclined Sidewall Design on Magnetohydrodynamic (MHD) Forces in an Aluminum Electrolytic Cell

This study presents a mathematical model investigating the effects of magnetohydrodynamics (MHD) in an aluminum reduction cell, utilizing numerical approximation via finite element methods. The model incorporates the magnetic fields generated from the cell cathode bus as well as from adjacent cells. Key objectives include the three-dimensional simulation of the Lorentz force distribution resulting from current variations in both the cathode bus and the cell linings, particularly in relation to an inclined sidewall design that alters current direction. The significance of this work lies in two main features: developing a numerical method for predicting the Lorentz field distribution and assessing how sidewall design influences current distribution and MHD forces. Findings indicate that the Lorentz force magnitude peaks near the sidewall, with its radial component instigating a concentric rotational flow field, contributing to the phenomenon known as metal 'heave.' The results vary with different inclination angles (50 to 64 degrees) of sidewall insulation and varying pot-line currents (140 to 180 kA), demonstrating that the slope of the sidewall substantially affects the resultant Lorentz force, thereby impacting the convective flow of metal and bath in the electrolytic cell.