Hydrodynamic characteristics of a horizontal pulsed solvent extraction column

A horizontal configuration for a pulsed solvent extraction contactor has been recognized as having a great potential in replacing standard vertical pulsed columns (VPC) in the separation of heavy elements in the reprocessing of spent nuclear fuel.;Hydrodynamic behaviour was characterized in terms of throughput capacity, dispersed phase holdup, axial mixing of both phases and power dissipation. Emphasis in this study was given to the effects of the major operating variables: aqueous and organic flowrates, and pulse amplitude and frequency, on the key hydrodynamic factors. The effects of physical properties for liquid-liquid systems and plate geometry were also examined for selected hydrodynamic factors.;The variation of throughput capacity with the operating variables was found to be similar to that reported for the VPC when presented on standard flooding diagrams. The flooding behaviour of the HPC was strongly dependent on both pulse amplitude and frequency, as well as on the coupled pulse effect represented by pulse velocity.;A detailed analysis of the dispersed (aqueous) phase holdup was made. The aqueous holdup did not vary significantly along the column, however, local radial variations are reported.;Axial mixing, as determined by a two-point tracer method of measurement, was well represented by a backflow model. Axial mixing of the dispersed (aqueous) phase was found to be insignificant. The effects of the major operating variables on the organic phase axial mixing in the HPC were consistent with similar data reported for the VPC.;Power dissipation studies, by the force-displacement method, revealed a pronounced dependency on the pulse amplitude-frequency product. Individual phase flowrates were found to have a minimal effect on the time-averaged power dissipation. Experimental results were in good agreement with a quasi-steady state model commonly used for the VPC.;A comparison of the major hydrodynamic factors for the HPC with the VPC suggested that the HPC can be a viable alternative where space and portability factors are critical. (Abstract shortened with permission of author.)...