Mean Drop Size and Drop Size Distribution in a Hanson Mixer-Settler Extraction Column

Drop size distribution and Sauter-mean drop diameters have been measured in a pilot scale Hanson mixer-settler extraction column for two different liquid-liquid systems. The experiments were carried out for both mass transfer directions. The effects of agitation speed and dispersed phase and continuous phase flow rates have been investigated under a variety of operating conditions. Mean drop diameter axial profiles show a strong nonuniformity, while drop size distribution does not change significantly with the column height. Sauter mean diameter and drop size distribution are strongly affected by agitation speed and interfacial tension. Significant, but weaker are the effects of continuous phase and dispersed phase flow rates. An empirical correlation for mean drop size as a function of Weber number, dispersed phase holdup, and viscosities ratio is suggested. In a further correlation, the dispersed phase holdup is replaced by flow rates which will certainly be known in a practical case.