Experimental investigation of mass transfer in high viscosity media

Abstract

An experimental study on mass transfer in high viscosity media was carried out in a sparged stirred vessel with a double helical ribbon impeller (HRI). The effects of stirring speed, superficial velocity of sweeping gas and media viscosity on volumetric mass transfer coefficient k L a were investigated under the conditions of viscosity from 10 to 300 Pas, superficial velocity of sweeping gas 0.00067 to 0.01 m/s and stirring speed 5 to 250 rpm. The results show that k j a increases with increasing stirring speed and superficial velocity of sweeping gas and decreases with increasing media viscosity in normal operating conditions. Too high stirring speed will deteriorate the flow of liquid thereby resulting in the passive effect on the mass transfer in the sparged stirred vessel dealing with very high viscosity media. For prediction of the mass transfer coefficient, an empirical correlation based on stirring speed, superficial velocity of sweeping gas and media viscosity has been proposed. It reproduced our experimental results with relative error within 20%.