Liquid-solid mass transfer from horizontal woven screen packing in bubble column reactors

The effect of gas sparging on the rate of mass transfer at horizontal singl e screen and stacks of closely packed horizontal screens was studied by an electrochemical technique which involved measuring the limiting current of the cathodic reduction of potassium ferricyanide. Variables studied were: d istance between the sparger and the screen, screen characteristics, e.g., m esh number and wire diameter, physical properties of the solution and super ficial gas velocity. Screen characteristics were found to have little effec t on the rate of mass transfer. The mass transfer measurement at beds of closely packed screens revealed th at the mass transfer coefficient decreased below the single screen value wi th increasing the number of screens per bed. Comparison of the present data with previous results showed that screens produce higher rates of mass tra nsfer than other geometries under otherwise the same conditions. The import ance of the present work to the design and operation of catalytic and elect rochemical reactors was highlighted.