Inert anode has been a hot issue in the aluminum industry for many decades. With the help of FEA(finite element analysis) software ANSYS,a model was developed to simulate the thermal stress distribution working condition of an inert anode. To reduce its thermal stress,the effect of some parameters on the thermal stress distribution was investigated,including the anode height,the anode radius,the hole depth,the hole radius,and the radius of inner chamfer and outer chamfer. The results showed that in the actual working condition of an inert anode,there existed a large axial tensile stress near the tangent interface between the anode and bath,which was the major cause of anode breaking. Increasing the anode height and reducing the hole depth properly seemed to be beneficial for the stress distribution. With the increase of anode radius,the stress distribution became better first and then deteriorated,the reasonable value was between 0.045 to 0.06m. The hole radius had a significant effect on the stress and a smaller radius would reduce the thermal stress. The effect of the radius of the inner chamfer and the outer chamfer was less than other parameters.
Two finite element(FE) models were built up for analysis of stress field in the lining of aluminum electrolysis cells.Distribution of sodium concentration in cathode carbon blocks was calculated by one FE model of a cathode block.Thermal stress field was calculated by the other slice model of the cell at the end of the heating-up.Then stresses coupling thermal and sodium expansion were considered after 30 d start-up.The results indicate that sodium penetrates to the bottom of the cathode block after 30 d start-up.The semi-graphitic carbon block has the largest stress at the thermal stage.After 30 d start-up the anthracitic carbon has the greatest sodium expansion stress and the graphitized carbon has the lowest sodium expansion stress.Sodium penetration can cause larger deformation and stress in the cathode carbon block than thermal expansion.
