Intensification of mass transfer in a pulsed bubble column

Abstract

The application of liquid pulsations to a classic bubble column substantially changes the hydrodynamics of bubble flow and the process of mass transfer. The paper presents a wide range of experimental results concerning the intensification of mass transfer in a pulsed bubble column of square cross section with side D=0.135m and slenderness ratio Hp/D ranging from 3 to 14.5. Experimental measurements were carried out at a frequency ranging from 1 to 70Hz and the amplitude of a disk vibration exciter from 0.25 to 2mm.The effect of liquid pulsation and volumetric gas flow rate on gas hold-up εG, mass transfer coefficient kLa and free liquid surface deflection Yi was investigated. It was shown that the application of pulsations to a bubble column caused a significant increase of gas hold-up and mass transfer coefficients. Based on the experimental results correlation equations for gas hold-up and mass transfer coefficient in a bubble column (with and without pulsations) were proposed and confirmed experimentally with an accuracy of ±15% and ±25%, respectively. A simple method in the form of a diagram has been proposed to determine optimal operating conditions of a pulsed bubble column.