The present article discusses the thermal and energy performance of an aluminum electrolyzer with side current feed when different areas of the electrolyzer (bottom, side blocks, man-made crust) are insulated with aluminum nitride. To reduce horizontal currents in the metal the vertical side of the man-made crust should be coated with aluminum nitride. Insulation of the upper horizontal side of the man-made crust affects the distribution of the current when the insulation is clad in a metal layer. The coating does not provide any protection for the cathode blocks because of the increase in the horizontal currents in the metal. Insulation of the edges is accompanied by an increase in the working voltage and greater consumption of electricity. This effect will be greater at start-up (no lining slag) and at the end of a run (i.e., when the lining slag is saturated with the smelt and also conducts current). Insulation of the bottom is justified only when done to produce a winterizing bath and after a reduction in electricity. Measures recommended for rectifying the profile of the lining slag are as follows: (a) winterize the edge beneath the blooms; (b) winterize the border; (c) reduce in heat losses of blooms through insulation of the blooms.
展开▼
