Diffusion and Back-Flow Models for Two-Phase Axial Dispersion

Abstract

S>Two-phase flow operations are described by a generalized model that assumes back flow, superimposed on the net flows through a column, with perfectly mixed stages in cascade. The diffusion model, which is used extensively to describe longitudinal dispersion, is derived as an extreme case of the back-flow model. The perfectly mixed stage (or cell) model is derived as another extreme. It is shown that the dispersed phase for these models may be treated as a second continuous phase. The nature of the longitudinal dispersion coefficient was also examined. (auth)