Abstract
The force generated by cathodic swelling, due to sodium penetration in the carbon blocks on the sides of a cathode shell of an aluminum reduction cell, is not only a function of the size of the cathode blocks but also of the structural strength of the shell. To analyze this effect and demonstrate its impact on the mechanical shell design, a numerical method was developed to calculate the maximum value of the internal forces in an Al reduction cell. The method considers the C blocks fully saturated with Na and, through an interactive technique, calculates the magnitude of the force between the cathode shell and the cathode C blocks as well as the deformation and stress distribution of the cathode shell. This method is capable of calculating the plastic deformation of the shell structure. This new interactive method was used successfully to examine a quarter of a cathode shell and gives one the possibility of calculating the internal pressure and deformation of complete cathode shells. This analysis is performed by means of the finite element method and specifically the commercially available software ANSYS is employed. The advanced computation techniques can present the shell deformation and stress development in an animated form.