US 12,698,567 B2Granted

System and process for starting up an electrolytic cell

AssigneeElysis Limited Partnership

InventorsBenoit Bardet, Sebastien Becasse, Leroy D'Astolfo, John Fors, Alain Noizet, Bruno Petitjean

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Abstract

It is disclosed a system and process for starting up an electrolytic cell. The system and process are particularly adapted for preheating an electrolytic cell or pot having cathodes before installing preheated anodes in the cell, for the production of a metal (e.g. aluminum). The system comprises one or more electrical heaters installed in the cell in place of the anode assemblies and can be used with a dry bath or a liquid melted bath (e.g. cryolite). The cell is preferably preheated by as many cell preheaters as there are anode assemblies. The cell preheater is preferably powered by current available in the pot's busbar. The invention is environmentally friendly as being preferably adapted for preheating a cell working with inert or oxygen-evolving anodes. Furthermore, the starting up process allows optimizing/reducing the time necessary for starting up the electrolytic cell, while securing the materials located inside the cell.

A preheating system for preheating an electrolytic cell and for maintaining the preheated electrolytic cell in temperature, wherein the electrolytic cell comprises at least one cathode assembly located at a bottom section of the electrolytic cell and having a plurality of vertical cathodes, and wherein the electrolytic cell is configured for receiving at least one anode assembly, each of said at least one anode assembly comprising a plurality of vertical anodes extending downwardly towards the vertical cathodes once the anode assembly is installed in the electrolytic cell, the vertical anodes being inert or oxygen-evolving anodes extending from a top section of the electrolytic cell toward the cathodes, the at least one anode assembly configured for being preheated outside the electrolytic cell before being moved and placed in the electrolytic cell, the electrolytic cell being further configured to receive an electrolytic bath for the electrolytic production of a metal, wherein the preheating system comprises:

at least one electrical heater, each of the at least one electrical heater being configured to be installed in the electrolytic cell in place of one of the at least one anode assembly and configured for preheating the electrolytic cell before installing said one of the at least one anode assembly into the electrolytic cell;
wherein the electrolytic cell is configured for receiving a number NAA of the at least one anode assembly, with NAA≥1, the preheating system further comprising:
a number NCH of the at least one electrical heater, with NCH≥1, each of the at least one electrical heater being configured to be installed in the electrolytic cell in place of the at least one anode assembly, with NCH=NAA;
and
a power module operatively connected to each of the at least one electrical heater and configured for powering the at least one electrical heater with a current for preheating the electrolytic cell,
wherein the power module is configured to connect a main busbar of the electrolytic cell to each of the at least one electrical heater for providing the current available in the main busbar;
and
wherein the preheating system is configured to impose a power P by the current amperage A and the resistance RCH of the number NCH of the at least one electrical heater, with P=(RCH/NCH)*A2, and with the power P being then higher than a power required to heat up the electrolytic cell and configured to create a surplus of energy, the electrolytic cell being then configured to evacuate the surplus of energy.

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Abstract

Claims8