Generalized Design Equations for Backmixed Liquid Extraction Columns with Nonlinear Equilibria

Abstract

Two methods are described, in terms of the backflow model, for calculating explicitly the number of nonideal stages required in a backmixed multicompartment extraction column with nonlinear equilibria to achieve a given performance. These are analogous to methods described previously for differential extractors in terms of the diffusion model. In both cases the equilibrium curve is represented by two or three straight line segments, and the resulting equations are expressed in generalized form to cover both models. Worked examples indicate that the methods are of adequate accuracy for both design and scale-up of extraction equipment. One of the methods is also of particular value for the com..