Minimum agitation speed for liquid–liquid–gas dispersion in mechanically agitated vessels

The present investigation deals with the determination of the minimum agitation speed, Ncdg, for complete liquid–liquid dispersion in mechanically agitated liquid–liquid mixtures sparged with a gas phase. The minimum impeller speed needed to completely disperse a liquid–liquid system was accurately predicted by the Skelland and Ramsay correlation [Skelland and Ramsey (Ind. Eng, Chem. Res., 1987; 26(1): 77–81)]. A new correlation is proposed for the prediction of minimum agitation speed, for three phase (liquid–liquid–gas) system as:A plot of (Fr)min predicted by the above equation and those obtained experimentally showed excellent agreement. This expression correlates experimental data of the present investigation with in a maximum error of ±15%.