Modelling sieve tray hydraulics using computational fluid dynamics

We develop a computational fluid dynamics (CFD) model for describing the hy drodynamics of sieve frays. The gas and liquid phases are modelled in the E ulerian framework as two interpenetrating phases. The interphase momentum e xchange (drag) coefficient is estimated using the Bennett et al. (1983) cor relation as basis. Several three-dimensional transient simulations were car ried out for a 0.3 m diameter sieve tray with varying superfical gas veloci ty, weir height and liquid weir loads. The simulations were carried out usi ng a commercial code CFX 4.2 of AEA Technology, Harwell, UK and run on a Si licon Graphics Power Challenge workstation with six R10000 200 MHz processo rs used in parallel. The CFD simulations reflect chaotic tray hydrodynamics and reveal several liquid circulation patterns, which have true three-dime nsional character. The clear liquid height determined from these simulation s is in good agreement with the Bennett correlation. It is concluded that CFD can be a powerful tool for modelling and design of sieve trays. (C) 2000 Elsevier Science S.A. All rights reserved.