Hold-up and characteristic velocity in a novel pulsed extraction column

The performance of the conical cross flow plate was tested in a pulsed extraction column of 75mm inner diameter, and the effects of pulsed intensity and superficial velocity of both liquid phases on hold-up and characteristic velocity were investigated under no-mass transfer using two systems: kerosene-water and 10% tributyl phosphate in kerosene-water. The results show that the hold-up is approximately proportional to the dispersed phase velocity, while the effects of continuous phase velocity have little impact under experiment operating range. With the increase of pulsed intensity, the hold-up first reduces and when the pulsed intensity reaches the critical value (Af)t, the hold-up increases rapidly. Compared with the critical value of pulsed sieve plate column, and the two systems decrease about 9.7% and 41.4%, respectively. Moreover, the characteristic velocities decrease with increasing pulsed intensity and the characteristic velocity of the system with lower interfacial tension decreases faster. Based on the analysis of the experimental results, empirical correlations of hold-up and characteristic velocity are proposed by dimensional analysis method, and a good agreement between the experimental values and the predicted values from empirical correlations is proved with the maximum relative errors less than 20%, which can be used for the design calculations of pulsed extraction column. © 2021, Chemical Industry Press Co., Ltd. All right reserved.