Hydrodynamics in spray and packed liquid-liquid extraction columns: A review

Abstract

This work provides a review of hydrodynamic characteristics such as the slip velocity, the dispersed-phase holdup, mean drop size, and axial dispersion of non-mechanically agitated liquid-liquid (L-L) extractors, with special reference to spray and packed bed columns. The complexity and importance of hydrodynamic behavior in designing and scaling up L-L extractors was a driving force to analyze, compare and discuss some important experimental findings available in the literature. The effects of phase velocities and the dispersed-phase holdup on the slip velocity, the mean drop size and the axial dispersion coefficient were studied and presented. Empirical correlations for slip velocity, the Sauter mean drop diameter and the axial dispersion coefficient, which were taken from the literature, were commented in terms of their applicability.