Hydrodynamics Analysis of a Folding Sieve Tray by Computational Fluid Dynamics Simulation

Abstract

In this reported work, a new type of tray, a folding sieve tray (FST), consisting of duplicated perforated oblique planes folding at a specific angle was designed. A three-dimensional two-fluid CFD model was employed to predict the hydrodynamics performance of a 0.6 m FST at different folding angles (48° and 90°) and opening ratios (10.2%, 12.5%, and 15.0%), compared with a 0° unfolding-structure sieve tray (ST). The models used in this study were within the two-phase Eulerian framework to ensure that the gas and liquid phases were an interpenetrating continuum. To verify the reliability of the models, the simulation results were compared with experimental results and were found to be in good agreement, and the relative error was less than 10%. The backmixing, pressure drop, clear liquid height, froth height, entrainment and the details of the gas–liquid distributions on the tray were investigated. Better operational stability was found in FST that resulted from the better liquid distribution, a lower pressure drop across the tray, and a relatively smaller clear liquid height. It was shown that gas in the FST had a higher horizontal velocity near the holes to guide the liquid phase. About 90% of backmixing, 50% of clear liquid height, and 30%of wet tray pressure drop were reduced in the FST.