Increasing the power modulation window of aluminium smelter pots with shell heat exchanger technology

Abstract

With power prices constantly rising, and varying aluminium prices requiring operating flexibility, the financial incentive for smelters to adopt a power modulation strategy is becoming larger. However, the power modulation window, in which a smelter can safely operate its reduction cells, is limited. The Light Metals Research Centre has developed the Shell Heat Exchanger (SHE) technology for controlling the heat dissipation from aluminium smelting pot shells. By varying the air flow through the SHE, the heat removal from the shell can be increased or decreased as desired, doubling the previous power modulation window or allowing power modulation with minimal disturbance to the pot thermal balance. This paper presents experimental results from LMRCs test facility, which show the shell temperature response when the SHE is operated in cooling or insulating mode. Steady state thermoelectric model results for these operating scenarios are also presented, outlining the impact on ledge thickness and other pot operating conditions.