Residence time distribution of droplets within discs and doughnuts pulsed extraction columns via Lagrangian experiments and simulations

This paper is devoted to the study of the transport of single droplets in discs and doughnuts extraction pulsed columns. Video experiments are carried out on a pilot plant of industrial size (D = 300 mm) in order to extract the values of the plug flow with axial dispersion transport model parameters (i.e. mean residence time and axial dispersion coefficient). The same kind of results are established thanks to Lagrangian simulations carried out with the industrial computational fluid dynamics (CFD) code ESTET (EDF, SIMULOG). A detailed study of the influence of the simulation conditions (expressions of the forces, turbulent dispersion and rebound modelling) is led in order to set the limits of such an approach. The agreement between experiments and simulations is around 20%. This study leads to the conclusion that the quality of the results seems to depend strongly on the prediction of the continuous phase flow turbulence. (C) 2003 Elsevier Science B.V. All rights reserved.