Energy-saving technology of mass transfer in tray columns with separate phase movement

Abstract

The comparison of formalized models, describing the operation of mass transfer column devices allows determining the type of equipment with the lowest power consumption in processes. For tray columns, the most widespread model is the model of theoretical contact phase, offered by McCabe-Thiele [1]. This model is based on the column material balance by distributed component and can be summarized in two postulates. 1. The concentration of volatile component in the contact phase is constant. 2. Vapor removing from the phase is in balance with liquid leaving the phase. In this case, the hydrodynamic indices of liquid and vapor flows are reduced to the perfect mixing models. The use of combinations of the other hydrodynamic models for liquid and vapor phases allowed Lewis to draw conclusions on significant enhancement of component separation. The greatest effect is achieved upon perfect displacement by vapor and liquid and single-direction movement of liquid in adjacent contact phases. All subsequent studies in this segment were aimed at industrial implementation of W.K. Lewis[2] conclusions. In particular, M.R. Cannon [3] suggested the following phase interaction mode. While the vapor passes through the column, the liquid doesn’t flow from tray to tray, and if the liquid overflows, it is not mixed on adjacent trays. The aim of the present paper is to determine the correlation between all offered models from the prospective of energy consumption during the separation process.