Effect of Inlet Downcomer on the Hydrodynamic Parameters of Sieve Trays Using CFD Analysis

Nowadays distillation is recognized as one of the economical and the most trustable separation methods in chemical, petroleum, gas and petrochemical industries. It is almost used as a first and the most applicable choice in separation methods. In this article the effect of inlet downcomer on the hydrodynamics of industrial sieve tray has been elaborated. The study was carried out by using a 3-D Computational Fluid Dynamics (CFD) method and was confirmed with experimental data. Commercial Ansys CFX 11 package software was used for the CFD analysis. Liquid velocity distribution on the tray was in better agreement with experimental data in comparison with simulation results without including inlet downcomer effect. Hydrodynamic parameters of clear liquid height, froth height and average liquid volume fraction in froth were predicted and compared with two available correlations. It was concluded that for having a better simulation model and hence having a deeper insight into tray performance, the downcomer effect on the mass transfer and hydraulic should be considered with CFD analysis.