Holdup, characteristic velocity and slip velocity between two phases in a multi-impeller column for high/medium/low interfacial tension systems

Abstract

In this research work, liquid–liquid extraction via three different systems has been investigated for determination of holdup, slip velocity and characteristic velocity in a multi-impeller column. The effects of the agitation speed, dispersed as well as continuous phase velocity, direction of mass transfer, and interfacial tension were studied. The findings revealed that an increase in agitation speed and continuous phase velocity led to the reduction of slip velocity while it increased with increasing dispersed phase velocity. More buoyancy and faster upward movement of larger drops accelerate the slip velocity in the dispersed to continuous phase mass transfer condition as compared with the case of no mass transfer. Empirical correlations for prediction of holdup, and slip and characteristic velocities are recommended. The results of the proposed correlations were compared with the experimental data obtained from the literature and the present investigation. Findings of this study demonstrated that the proposed correlations give accurate predictions for slip velocity, characteristic velocity and holdup.