HYDRODYNAMICS AND MASS-TRANSFER IN A COCURRENT PACKED-COLUMN - A THEORETICAL-STUDY

A realistic model has been developed for the hydrodynamics and mass tr ansfer in a cocurrent packed column. It postulates that the liquid pha se is divided into stagnant and dynamic regions. Unlike in other model s, the stagnant phase is not completely mixed and its concentration pr ofile is given by a Fickian-type model equation. The model considers a xial dispersion in the dynamic phase and mass transfer between the sta gnant and dynamic regions of the liquid phase. The resulting partial d ifferential equations are solved numerically by the method of orthogon al collocation. Simulation results highlighting the effects of various parameters for a step input and a step decrease in tracer concentrati on are also presented. The model predictions for both the downflow and upflow modes of operation are compared with available experimental da ta and are found to agree well.