Effect of fluidizing solids on wall-liquid mass transfer in a cylindrical cell with rotating central rod

Abstract

Limiting current density data were obtained at point electrodes fixed flush with inner surface of the outer cylinder of an electrochemical cell in which a coaxially placed cylindrical rod is rotated at different rotational velocities in the presence of fluidizing solids. The variables covered in the present study are rpm of inner annular rod, diameter of rod, solid fraction and flow rate of the electrolyte. Mass transfer coefficients, which were computed from limiting current density data, were found to increase with an increase in the velocity of the fluid electrolyte through the annular cell in the presence of fluidizing solids. No specific trend was observed with respect to the rpm of the central annular rod. The variation in mass transfer coefficient values due to change in the rod diameter was just marginal. The bed expansion data represented Richardson-Zaki equation with an exponent of 2.15. Colburn jD-factor format has been used to correlate the data on mass transfer coefficients.