Prediction of axial mixing coefficients in rotating disc and asymmetric rotating disc extraction columns

Abstract

The correlation of axial mixing in the continuous and dispersed phases of rotating disc and asymmetric rotating disc columns is presented. Published experimental results on continuous‐phase axial mixing for both single‐ and two‐phase flows, obtained with tracer injection methods and by solute concentration profiles, are considered. The correlation developed is based on 1055 data points for 32 liquid systems obtained by 19 different investigators. The axial mixing in rotating disc columns is found to be up to 20% larger than in asymmetric rotating disc columns. Data for the dispersed phase are harder to correlate than those for the continuous phase. Since the available results are often contradictory, the correlation for the dispersed‐phase coefficient is thus less accurate than that for the continuousphase coefficient.

Continuous Extraction of Europium(III) by Ionic Liquid in the Rotating Disk Column with an Asymmetrical Structure Aimed at the Evaluation of Reactive Mass Transfer

“…The axial dispersion coefficient for the dispersed phase was assumed to be negligible in the selected equations, and this coefficient for the continuous phase was replaced by Kumar and Hartland. 38 The results of the numerical solution of the equations are shown in Figure 4 for the volumetric overall mass-transfer coefficient. The variation of the concentration distribution inside the column for both selective systems is shown in Figures 5 – 7 .…”

Use of axial dispersion model for determination of Sherwood number and mass transfer coefficients in a perforated rotating disc contactor

“…According to the axial diffusion model and material balance inthe extraction column, over the differential elements of the extraction column witha total effective height, H, the equation set for steady state process is established using following equation, under the constant superficialvelocities V c and V d at any given agitation rate [16]:…”

Spray and packed liquid–liquid extraction columns: drop size and dispersed phase mass transfer

“…The correlations of Kumar and Seibert (Eqns , , and ) were utilized to investigate the correctness of our correlations for predicting the mass transfer coefficient (Eqns and ) . A comparison between Eqns and revealed that % AARD was about 60.2%.…”

“…One of the most important parameters in liquid–liquid extraction columns is the dispersed phase droplet behavior, because of its effect on mass transfer coefficient . A large amount of work exists in the literature concerning the prediction of drop size distribution in liquid–liquid dispersions in extraction columns, and most of them are only applicable for particular conditions of those processes …”

“…Kumar et al . have derived a correlation for the dispersed phase mass transfer coefficient of spray extraction columns: where K d is the dispersed phase mass transfer coefficient, D M is the diffusion coefficient, Re c is the continuous phase Reynolds number, Sc d is the dispersed phase Schmidt number, and ρ c is the continuous phase density.…”