Kamath, M.S.Subba, Rau, M.G.2020-03-312020-03-311985The Canadian Journal of Chemical Engineering, 1985, Vol.63, 4, pp.578-584https://idr.nitk.ac.in/handle/123456789/12614This paper reports on the optimum range of rotor speeds for the operation of Rotating Disc Contactors (RDC). New information based on experimental investigations is presented regarding the existence of a second critical rotor speed which divides the varying characteristic velocity region into rapidly varying and gradually varying characteristic velocity regions of the dispersed phase droplets. New modifications to the reported generalised correlations for the prediction of characteristic velocity at all rotor speeds under conditions of no solute transfer as well as solute transfer between dispersed and continuous phases are suggested. Copyright 1985 Canadian Society for Chemical EngineeringArticle