Study of Mixing of Phases inside the Sieve Tray Using Computational Fluid Dynamics

In the present study a three-dimensional Eulerian-Eulerian Computational Fluid Dynamics (CFD) model was developed to predict the hydrodynamics behavior of industrial scale sieve trays, for study of phase mixing inside the tray. The dispersed gas and the continuous liquid phases are as two interpenetrating phases. Three parameters consisting distribution of density of mixture, volume fraction distribution and interfacial area density were evaluated as characteristics of mixing. Four regions consisting near wall region, the area between adjacent holes, behind the entrance and exit weirs are distinguished as regions with poor mixing. Plug flow with almost uniform phase mixing was seen at central region of tray. The extent of mixing is depended on the gas and liquid flow rates, and the response of central region and above mentioned 4 poor mixing areas to change of gas and liquid flow rates are different. The results showed that proposed model can well predict some details of phase mixing characteristics, while known methods have not ability to show them.