Prediction of dispersed phase holdup in pulsed disc and doughnut solvent extraction columns under different mass transfer conditions

Using experimental data from a number of pulsed disc and doughnut solvent extraction columns, a unified correla-tion for the prediction of dispersed phase holdup that considers the effects of mass transfer is presented. Pulsed disc and doughnut solvent extraction columns (PDDC) have been used for a range of important applications such as ura-nium extraction and nuclear fuel recycling. Although the dispersed phase holdup in a PDDC has been presented by some researchers, there is stil the need to develop a robust correlation that can predict the experimental dispersed phase holdup over a range of operating conditions including the effects of mass transfer direction. In this study, dis-persed phase holdup data from different literature sources for a PDDC were used to refit constants for the correlation presented by Kumar and Hartland [Ind. Eng. Chem. Res.,27 (1988),131–138] which did not consider the effect of col-umn geometry. In order to incorporate the characteristic length of the PDDC (i.e. the plate spacing), the unified cor-relation for holdup proposed by Kumar and Hartland based on data from eight different types of columns [Ind. Eng. Chem. Res.,34 (1995) 3925–3940] was refitted to the PDDC data. New constants have been presented for each hold-up correlation for a PDDC based on regression analysis using published holdup data from PDDCs that cover a range of operating conditions and physical properties and consider the direction of mass transfer.