Mass transfer characteristics of gas-sparged fixed-bed electrodes composed of stacks of vertical screens

Mass transfer rates at a gas-sparged fixed-bed electrode made of stacks of vertical screens were studied by measuring the limiting current for the cathodic reduction of potassium ferricyanide. Variables studied were air flow rate, physical properties of the solution and bed thickness. The mass transfer coefficient was found to increase with increasing air flow rate up to a certain point and then remain almost constant with further increase in air flow rate. Increasing bed thickness was found to decrease the mass transfer coefficient. Mass transfer data were correlated by the equation $$J = 0.2(ReFr)^{ - 0.28} ({L \mathord{\left/ {\vphantom {L d}} \right. \kern-\nulldelimiterspace} d})^{ - 0.28} $$ For a single vertical screen electrode the data were correlated by the equation $$J = 0.187(ReFr)^{ - 0.26} $$