(457a) Augmentation of the Rate of Mass transfer Limited Liquid–Solid Heterogeneous Reactions by Turbulence Promoters

Intensifications of the rate of mass transfer limited electrochemical and catalytic reactions taking place at the external surface of a helical coil imbedded in an inert fixed bed of cylinders acting as turbulence promotors was studied by the electrochemical technique where the rate of mass transfer was obtained from the limiting current of the cathodic reduction of K₃Fe (CN) ₆ in presence of NaOH as a supporting electrolyte.

Variables studied were velocity of the solution, packing cylinder diameter, helical coil tube diameter and the solution physical properties. Results revealed that the mass transfer coefficient at the outer surface of the helical coil increases with increasing solution velocity and decreasing packing cylinder diameter, helical coil tube diameter was found to have a slight effect on the mass transfer rate. The following dimensionless equation was found to fit the data

Sh = 7.14*10^-4 * Sc^0.33 * Re^0.52 * (d_p/d)^-2.32

The importance of this equation in the scale up and operation of the present reactor was pointed out. The possible use of the coil inner surface as a builtin heat transfer facility for conducting exothermic electrochemical and catalytic reactions which need rapid cooling was highlighted. The possibility of using multi imbedded coaxial helical coils of different coil diameter in practical catalytic reactors to increase their rate of production was noted.