Longitudinal Mixing of Liquid in Batchwise Multi-Stage Bubble Columns

Longitudinal mixing of liquid in multi-stage bubble columns for batch operation without liquid flow through the column was measured by an impulse response method. The observed mixing characteristic of liquid for air-water system was well expressed by the dispersion/back-flow model, in which the dispersion in each stage and the back-flow between stages were taken into consideration. By assuming that the dispersion coefficient in a multistage column was identical to that in a single-stage column, back-flow rate of liquid was determined from the observed response curve. A correlation for back-flow rate is proposed.