Axially dispersed phase holdup and drop size distribution were investigated in a 65mm inside diameter by 3m(overall) high pulsed perforated-plate extraction column using 30%TBP+70%n-Dodecane and 0.1M $HNO_3$ system. Influences of pulse velocity, superficial velocity of each phase, phase flow ratio and axial position along the height of column on holdup and drop size distribution were determined.
All the data were obtained with solvent as the dispersed phase at steady state conditions as determined by the attainment of steady differential pressure across the plate section.
The results of axially dispersed phase holdup and Sauter-mean diameter profiles showed the presence of 'entrance' and 'exit' regions in the plate section. The presence of a local maximum in holdup was explained in terms of drop breakage-coalescence process, and find drop accumulation resulting from the continuous phase superficial velocity and over-sized bottom disengagement section.
A mixture of multi and uni-modal drop size distributions with long tails was found for low pulse velocity and bottom section of the column while the tails were considerably reduced in the case of high pulse velocity. The drop size distribution data could be represented by Gamma distribution.
Empirical correlations for holdup and Sauter-mean diameter, interfacial area and Gamma distribution parameters were obtained.
