CFD Analysis of Liquid-Liquid Extraction Pulsed Sieve-Plate Extraction Columns

Pulsed sieve-plate extraction columns (PSECs) are extraction equipment with a wide range of applications and are commonly used in nuclear fuel reprocessing. A computational fluid dynamic model of a PSEC has been developed and run with a two phase flow consisting of water and kerosene. The PSEC investigated consists of two perforated plate internals, operated under 1 Hz pulsing frequency and 20 mm amplitude, with a 39.6 mm column diameter and a plate spacing of 50 mm. The CFD used was based on unsteady flow calculations undertaken with a conventionally used unsteady Reynolds-averaged Navier-Stokes (URANS) approach, closed with the standard k-ε turbulence model, and a large eddy simulation (LES). Results are compared with empirical correlations, and the LES predictions of the turbulent flow in the column are found to be superior. The CFD analysis brings valuable insight into the hydrodynamics in PSECs and provides better understanding on the multi-phase flows in these devices.