Correlations for the prediction of NTU and mass transfer coefficient for a VPE

Abstract

Liquid-liquid extraction is the separation of the constituents of a liquid solution by contact with another insoluble. The reciprocating column (RPC) and vibrating plate column (VPE) are two types of mechanically aided columns. This paper aims at developing appropriate correlations for the prediction of NTU/HETS and the mass transfer coefficient, kox for the VPE based on the agitation level of the plates (af – the product of frequency and amplitude of the plate motion), the plate spacing and the flow rates which will allow for the simplification in the design of this type of column. The system chosen was the acetone-toluene-water system (standard test system – EFCE) with the acetone in toluene forming the feed that is dispersed in the column as it moved upward while the water moved as a continuous phase down the column. Experiments were conducted to evaluate the hydrodynamics of the droplets moving up the column and to evaluate the mass transfer that occurs (in order to evaluate NTU, HTU and kox) while varying the agitation levels and spacing of the plates in the column. Successful correlations were developed using some of the experimental data and these correlations were verified with additional data.