The dynamic behaviour of liquid-liquid agitated dispersions—I. The hydrodynamics

Abstract This paper develops a new numerical algorithm for the hydrodynamics of liquid-liquid systems with simultaneous coalescence and break-up. The algorithm is precise and fast in the computation of the transient behaviour of single continuous or batch stirred vessels, requiring computing times compatible with its use in control applications. The Coulaloglou-Tavlarides drop interaction model is used, and the predictions obtained for the asymptotic steady state are compared with those obtained for the same conditions by Guimaraes, both by moment-generating functions and by a Monte-Carlo (Bastenaire's point) technique, with an agreement better than 0.2%; those two previous algorithms, however, are not applicable to dynamic conditions. Although in the two case studies discussed herein the Coulaloglou-Tavlarides interaction model is used, the new algorithm accommodates virtually any other models or equations describing drop interaction. The algorithm has also been extended to the simulation of mass transfer, thus being the first potentially able to predict the full trivariate behaviour of liquid-liquid dispersions in transient, dynamic, conditions, within reasonably short computation times.

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