Research On The Holdup In Pulsed Sieve-plate Extraction Column

This paper is designed to study the dispersed phase holdup in pulsed sieve plate columnusing experimental measurements and computational fluid dynamics simulations. Theexperiments and CFD simulations were conducted on38mm diameter pulsed sieve platecolumn that has standard geometry:50mm plate spacing,3mm hole diameter and23%fractional free area. Water was used as dispersed phase with30%tributyl phosphate-keroseneas the continuous phase.The total holdup of the dispersed phase was measured through volume displacementmethod. And the effects of pulsed velocity, phase flow rates on the dispersed phase holdupwere studied. From the systems studied the dispersed phase holdup can be predicted from twoempirical correlations:φ=4.0639（Af）^0.4435（u_d+u_c）^0.2145u_d^0.2601u_c^0.0539and φ=3.9483（Af）^0.4436（u_d+u_c）^0.3634u_d^0.1625A very good agreement between the calculated values from these two empiricalcorrelations and the experimental data was observed, in the experiment condition.Simulations were carried out using CFD software, with standard k-ε model and Eulermultiphase flow model. The simulation results were in agreements with the experimentsresults. The results show that:2d model simulation can give the axial distribution of holdupin the pulsed sieve plate column. And3d model simulation could get the information of theflow field in the pulsed sieve plate column. The value of2d simulation result was smallerthan experiment date and the relative error was about15%. The value of3d simulationresult was better agree with experiment date than the result of2d simulation, and therelative error of that was about10%.