Fluid Separation Modelling in the Columns Equipped with Structured Packings using the Hydrodynamic Analogy

A new modelling approach to the description of mass and heat transfer in columns equipped with structured packings is developed based on rigorous equations of continuum mechanics. This approach rests on the analogy between the flow patterns in real structured packings and film flow. The physical model is based on a simplified geometrical representation of the packing. It consists of a bundle of channels with identical cross section. The channel inner surface is wetted by a liquid, whereas the rest of the volume is occupied by a counter-current vapour flow. Both phases are assumed to be laminar and ideally mixed at regular intervals. The mathematical model comprises a set of partial differential equations describing hydrodynamics, heat and mass transfer phenomena. A numerical solution of the whole problem yields velocity profiles as well as concentration and temperature fields throughout the column. The model is verified using experimental data for a binary and a ternary distillation, in a column equipped with Montz-Pak A3-500.