Development of a CFD-PBE coupled model for the simulation of the drops behaviour in a pulsed column

The pulsed column is a widely used technology for liquid-liquid extraction processes in various industries. In this work, the use of this technology has been extended to perform continuous precipitation. An original process of continuous precipitation in emulsion in a pulsed column is thereby developed. A thorough understanding of the behaviour of the dispersed phase inside the column helped to achieve process optimisation and is the purpose of this paper. In this aim, a coupled computational fluid dynamics (CFD)-population balance equation (PBE) approach was developed for the simulation of this original process, and allows the determination of the mean droplet size, which is a key parameter. On one hand, breakup and coalescence kernels for the PBE were selected by performing homogenous type experiments in a stirred tank reactor. The parameters of those kernels were adjusted by fitting the models' parameters to the measured droplets size distribution (DSD) in the stirred tank. One another hand, the continuous phase flow inside the pulsed column was investigated by CFD and has been validated using particle image velocimetry (PIV) data. The latter helped us to choose the best turbulence model representing the flow inside the pulsed column. Finally, the coupled CFD-PBE model was implemented using the quadrature method of moments (QMOM) in the CFD code ANSYS-Fluent (R) to determine the mean droplet size inside the column.

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