MHD of aluminium cells with the effect of channels and cathode perturbation elements

Abstract

The industry oriented MHD software for aluminium electrolysis cells is updated to take into account the variation of bottom and top surfaces of the cell cavity. The extended model capabilities include the presence of connected channels, height non-uniformities of the cell bottom affecting the liquid metal hydrodynamics and the electric current passage to the cathode with ridges and variable bottom ledge. The numerical results for 500 kA test cell are used to analyze the cell stability under combination of the effects. Perturbations created by the horizontal current density above the carbon elevations lead to the metal/electrolyte interface wave growth, which is opposed by the increased turbulent damping over the bottom with ridges. Optimization of the cell design permits to improve the cell stability and efficiency.