PHYSICAL MODELING STUDIES OF ELECTROLYTE FLOW DUE TO GAS EVOLUTION AND SOME ASPECTS OF BUBBLE BEHAVIOR IN ADVANCED HALL CELLS .3. PREDICTING THE PERFORMANCE OF ADVANCED HALL CELLS

For the effective removal of bubbles from the anode-to-cathode gap (AC G), an earlier study had suggested that advanced Hall-Heroult cells be operated with a ''grooved'' anode in the near-horizontal electrode co nfiguration. However, it was observed that a large number of bubbles d id not enter the grooves readily; the avoidance of this phenomenon cou ld further lower the interpolar resistance. To circumvent this problem , an ''improved'' anode design which would promote the entry of gas bu bbles into the grooves was conceived. A further objective was to analy ze the performance of advanced Hall cells equipped with this improved anode. For this purpose, measurements of (simulated) electrolyte veloc ities, interpolar resistance, and mass transfer coefficient at the cat hode were carried out in a ''water'' model. An important suggestion em erges from this work: energy savings of 2 to 2.5 kWh/kg aluminum may r esult when a conventional Hall cell is replaced by an advanced Hall ce ll equipped with this improved anode.