Effect of Phase Dispersion and Coalescing Material On Sieve Tray Capacity

The capacity of a sieve tray liquid-liquid extractor is often limited by inadequate drop coalescence. Previous studies carried out by the Separations Research Program in the 1990s demonstrated the effectiveness of open Teflon structured packing for minimizing entrainment of the continuous aqueous phase and increasing the extractor capacity by as much as 60%. However, the effects of dispersing the aqueous phase and using a sheet metal structured packing were not incorporated within these coalescence studies.

New sieve tray flooding experiments were performed to investigate the effect of phase dispersion and the application of Teflon or stainless steel structured packings as a coalescer. The experiments were performed using a 4-inch diameter (i.d.) glass extractor and the methyl isobutyl ketone/water test system. The dispersed to continuous phase volumetric flow ratio was varied from 0.1-10. The experimental results are compared with the SRP sieve tray flooding prediction.