CFD modeling of sieve and pulsed-sieve plate extraction columns

Present work deals with the development of a computational fluid dynamics (CFD) model for understanding the hydrodynamics in sieve and pulsed-sieve plate extraction columns. The model is based on Eulerian-Eulerian approach along with standard k-ɛ model for turbulence. The CFD model has been validated by comparing (i) the height of the accumulated layer of the dispersed phase under the plate, and (ii) hold-up of the dispersed phase on the sieve plates with the corresponding values calculated by the correlations reported by Laddha and Degaleesan [Laddha, G.S., Degaleesan, T.E., 1976. Transport Phenomena in Liquid Extraction. Tata McGraw Hills Publishing Co. Ltd., pp. 305-330]. Model predictions were found to be within ±10%. The validated model has been extended to study the regime transition in pulsed-sieve plate columns. Overall, the developed CFD model is found to be able to predict the hydrodynamic aspects of plate extraction columns: like variation in hold-up above and below the plate, movement of continuous phase across the plate and through the downcomer, different operating regimes at different pulsing velocities, etc.