Mass Transfer under Combined Gas Evolution and Forced Convection

Abstract

The combined effect of forced convection and bubble‐induced convection on mass transfer in an electrochemical cell with vertical planar electrodes is investigated experimentally. The results indicate that a minimum is established in the mass‐transfer coefficient due to the opposing effects of the two convections. A linear correlation exists between the rate of gas evolution and the rate of liquid flow at the minimum points. The effect of the cell gap is nonlinear, and it appears that a power dependence exists. Beyond the point of minimum, the mass‐transfer coefficient is dominated by the bubble‐induced convection and a universal correlation exists between the rate of gas evolution and the increase in mass‐transfer coefficient beyond the minimum value.