Mass transfer at the confining wall of an electrochemical cell in annular flow with a rotating central rod

An electrochemical method (limiting current technique) was used to obtain mass transfer coefficient (k(L)) in a flow reactor in which the coaxial inner cylindrical rod was rotated at different revolutions per minute (rpm). The effect of liquid velocity, rpm and rod diameter on the liquid-wall mass transfer coefficient was investigated. It was observed that at any given rpm, thek(L)increased with the liquid velocity. Rotation of the central rod was found to further augment the coefficient. Augmentations were found to be more significant at small liquid velocities. The effect of central (annular) rod diameter was also studied and thek(L)data were correlated using Colburnj-factor format. [GRAPHICS] .