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AssigneeAluminium de Grece
InventorSpyridon Casdas
Estimating the term…
A process and an apparatus is disclosed for controlling the supply of alumina of a cell for the production of aluminum by electrolysis using the Hall-Heroult process wherein each alumina supply orifice of the cell comprises a movable plunger which is electrically insulated from the superstructure of the cell and of which at least the end is electrically conducting and a means for measuring the potential between the end of the movable plunger and a point of the cell which is taken as reference potential. The plunger is moved with an alternating, substantially vertical, upward and downward movement and in each downward movement means detects whether the plunger has come into contact with molten electrolyte or with solidified electrolyte. In the first case, when molten electrolyte is detected the plunger is raised while in the second case when solidified electrolyte is detected the electrical power supplied to the cell is increased in order to remelt the solidified electrolyte.
In a process for controlling the supply of alumina to a cell for the production of aluminum by electrolysis of alumina dissolved in molten cryolite electrolyte, including providing storage, measurement and transfer of alumina to at least one alumina supply orifice which is held open in the crust which is formed at the surface of the electrolyte and into which a movable plunger can penetrate, and wherein the plunger is moved with a substantially vertical alternating upward and downward movement, the improvement comprising in each downward movement the detecting whether the plunger has come into contact with molten electrolyte or with solidified electrolyte, said detection being effected by measuring the electrical voltage between the plunger and a point of the cell which is taken as reference potential.
Dependencies are inferred from the claim text.