Free convective mass transfer at corrugated surfaces in relation to catalytic and electrochemical reactor design

Abstract

The free convective mass transfer behavior of V-corrugated horizontal and vertical surfaces was studied by measuring the limiting current of the cathodic deposition of copper from acidified copper sulphate solution. Variables studied were peak-to-valley height and angle of the V-grooves, physical properties of the solution and vertical electrode height. For vertical corrugated surfaces, the data were correlated by the equation: S h = 0.78 ( S c ⋅ G r ) 0.26 while the data for the horizontal corrugated surfaces were found to fit the equation: S h = 1.64 ( S c ⋅ G r ) 0.23 A comparison with the free convection mass transfer behavior of flat plates shows that the mass transfer coefficient at vertical corrugated surface is higher than that at vertical flat plates. For horizontal surfaces the reverse is true. The importance of the present results to the design and operation of electrochemical reactors, membrane processes and catalytic reactors which employ corrugated surfaces to conduct diffusion-controlled processes is highlighted.