ALCORUS ENGINEERING LTD

S. N. Akhmedov, Chairman of the Board

V. A. Kozlov, Chief Engineer, e-mail: office@alcorus.ru

Department of Theoretical Mechanics, Saint-Petersburg State Polytechnic University

V. V. Tikhomirov, Assistant Professor
V. A. Vostrikov, Lecturer

Based on the computer simulation the stressed state of cathode blocks in aluminium reduction cells, designed for the amperage from 180 to 500 kA was assessed. At the first stage the stressed-deformed state of the bottom was studied using 3D model under steady-state operation mode of cathode. The numerical modeling was done based on finite element meshes with similar typical dimensions of finite elements for each of cathodes. At the second stage of the study 2D tasks of plane strain deformation for the sections of longitudinal bottom symmetry were under consideration in order to investigate in details the stressed state of the blocks. With amperage increase in the center of cell bottom the increase of maximum values of the Mises intensity and compressing stresses takes place, while respective dependencies for extreme blocks have a dropdown nature, i.e. forces, acting onto the bottom periphery diminish. Thus, when increasing the cell amperage the operation conditions for central cathode blocks become stronger and, consequently, their damage and destruction probability increases. Determining factors for the bottom destruction are cracks, coming out from the corners of cathode block slots. With amperage increase at the corners of the slots in central blocks the increase of maximum principal stresses, which are of compressive nature, and the increase of principal tangent stresses take place. In similar corners of end blocks the situation is opposite – the steady decrease of the values of above mentioned stresses occurs. Design values of maximum Mises intensity for the stresses and maximum values for the compressive forces modulus in central blocks correlate with actual data on average service life of the cells. With amperage increase from 180 kA to 500 kA the average service life of the cells decreases.

1. Kvande H. Light Metals. 2008. pp. 375.
2. Benkahia B., Caratini Y., Mezin H., Renaudier S., Fardeau S. Light Metals. 2008. pp. 451
3. Pisarenko G. S., Lebedev A. A. Deformirovanie i prochnost materialov pri slozhnom napryazhennom sostoyanii (Deformation and Strength of materials under combined tension). Kiev, 1976. 416 p.
4. Tikhomirov V. V., Akhmedov S. N., Kozlov V. K. Tsvetnye Metally — Non-ferrous Metals. 2002. No. 6. pp. 47–51.