Patent ID: 9458545
Filing Date: 2016-10-04
CPC Classification: C25C

Claim Text:
1. A method of ventilating an aluminium production electrolytic cell comprising a bath with contents, at least one cathode electrode in contact with said contents, at least one anode electrode in contact with said contents, and a hood, defining an interior area covering at least a portion of said bath, the method comprising: drawing vent gases from said interior area through a cover interior area defined by a double-walled cover of an aluminium oxide feeder with each a crust breaker and a feeder pipe arranged within the cover interior area of the aluminium oxide feeder; cooling a full flow of vent gases drawn from the interior area using a first heat exchanger to produce cooled vent gases; drawing a portion of the cooled vent gases; circulating the drawn portion of the cooled vent gases to a second heat exchanger for further cooling to produce further cooled vent gases; and circulating at least a portion of the further cooled vent gases to the interior area via a passage formed between double walls of the double-walled cover, for a flow of at least a portion of said further cooled vent gases from between the double walls and into the interior area to form a curtain of further cooled vent gases around the feeder pipe from where aluminium oxide powder is supplied to the bath.