Расчет магнитогидродинамических параметров работы электролизеров с различным типом катодного кожуха

Abstract

The aim of the research was to analyse the influence of cathode casing design on electrolytic cells with self-baking anodes taking the following magnetohydrodynamic characteristics into account: magnetic field, speed and circulation direction of cathode metal, margin of magnetohydrodynamic stability. The most common type of electrolysers having a Söderberg anode and S-8BM top current lead, for which both counterforce and cradle cathode shell types were used, was taken as an object of study. To simulate the magnetohydrodynamic phenomena occurring in the electrolyser, we used the specialised Blums v5.07 computer program. The following settings were identical for both versions of the models: type of bus, anode assembly parameters, cathode material properties, formation features of the anode mass sintering cone and form of the working space. The calculation of the magnetic field of the electrolyser was carried out using an analytical research method based on the integration of the Poisson (for regions occupied by current) and Laplace (for regions not occupied by current) equations. According to calculations of the speeds and directions of movement of the cathode metal, both types of cathode casing of the electrolyser were shown to be characterised by a four-circuit circulation system, determined by the corresponding location of the anode risers at the inlet and outlet ends of the electrolyser. The results of mathematical modelling show that for electrolysers with a cathode shell of the cradle type, the transverse and vertical components of the magnetic field are less compensated than for cells having a counterforce shell, which affects the average speeds of the cathode metal: circulation speeds will be 0.02 cm / s below. However, the margin of magnetohydrodynamic stability is almost identical for both cathode shell designs. With the same shape of the working space, as well as interpolar distance (41 mm) and metal level (34 cm), the calculated margin of magneto-hydrodynamic stability was 360-380 mV.