Hall cell
AssigneeAlumax Inc.
InventorJohn J. Miller
Life of this patent
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Abstract
An improved aluminum reduction cell which includes an insulated container for the molten electrolyte, a cover over the open mouth of the container, and a heat exchanger positioned above the molten bath, within the container and below the cover for recovering heat from the molten bath and further including, in one embodiment, means for converting the recovered heat into electricity which can be recycled back to the reduction cell. By heavily insulating the reduction cell against heat loss and by appropriately controlling the amount of heat which is recovered the cell can be operated over a wide range of electrical power inputs.
Claims7
Improved apparatus for the production of aluminum, the apparatus being of the reduction cell type having a molten electrolyte bath containing dissolved alumina, an open mouthed container for the electrolyte bath, an anode and a cathode immersed in the bath, and means for applying an electric current between the anode and the cathode whereby aluminum is produced and resistance heat is generated, and wherein the improvement comprises
- thermal insulation surrounding the walls of the container,
- a refractory cover over the open mouth of the container,
- a heat exchanger positioned above the molten bath, within the container and beneath the cover for recovering heat from the molten bath,
- and means, including a temperature sensor for monitoring the electrolyte bath temperature, for selectively controlling the rate of heat recovery by the heat exchanger to maintain the electrolyte bath within a predetermined temperature range, irrespective of limited variations in the supply of electric current to the cell.
Dependencies are inferred from the claim text.