Experimental investigation on regime transition and characteristic velocity in a horizontal-vertical pulsed sieve-plate column

Abstract

In this study, we attempted to evaluate the flow regime transitions in a novel type of extractor, called a horizontal-vertical pulsed sieve-plate column, for three liquid-liquid systems: toluene-water, butyl acetate-water, and n-butanol-water, with a 3% volumetric fraction of acetone in the dispersed phase as a mass transfer agent. Moreover, due to the importance of the characteristic velocity, the effects of operating parameters, such as the pulsation intensity and flow rate of the phases, have been investigated in each section of the column. The characteristic velocity shows different behaviors with the variation of the operating parameters in each section, which has been thoroughly discussed in this study. New correlations for the transitions from the mixer-settler regime to the dispersion regime in the vertical section and from the dispersion regime to the emulsion regime in the horizontal section have been proposed, which indicate the lower and upper limits of the proper pulsation intensity to identify the operational range of the dispersion regime. Furthermore, new correlations have been proposed for the prediction of the characteristic velocity in each section of the column, with average absolute relative errors (AAREs) ranging from 9.81% to 11.15%, which represent a satisfactory agreement between the experimental and calculated data.