Natural Convective Mass-Transfer Behavior of Horizontal and Vertical Perforated Surfaces

Abstract

Rates of free convective mass transfer at horizontal and vertical perforated plates containing circular holes were measured by determining the limiting current of the cathodic deposition of copper from acidified copper sulfate solutions. Variables studied were the vertical plate height or horizontal disk diameter, the hole diameter, and the physical properties of solution. The data at the vertical perforated plate were correlated by the equation Sh = 0.1(Sc × Gr)0.33, while the data at the horizontal perforated plate were correlated by the equation Sh = 0.062(Sc × Gr)0.349. A comparison of the rate of mass transfer at perforated surfaces with that at unperforated surfaces shows that the rate of mass transfer at vertical perforated surfaces is almost equal to that at unperforated vertical surfaces, while for horizontal perforated surfaces the rate of mass transfer at horizontal perforated surfaces is lower than that at unperforated surfaces. Industrial implication of the present results for the electronic industry where perforated metallic casings are used to house electronic equipments is highlighted.