Simulation of the population balances for liquid-liquid systems in a nonideal stirred tank. Part 1 Description and qualitative validation of the model

A simulation model has been developed to model drop populations in a stirre d tank. A multiblock stirred tank model has been used with the drop populat ion balance equations developed in the literature. The stirred tank is mode led separately so that local turbulent energy dissipation values and fluid flows are used in the drop breakage and coalescence functions. This model h as several attractive features, e.g. it can predict the inhomogenity of dis persions and some scale-up phenomena. Because local conditions can be used in the drop rate functions needed in the population balances, it is possibl e to take these fundamental processes into closer examination. It seems tha t the parameter values in the drop breakage and coalescence models depend o n flow and turbulence averaging for the vessel. This proposes that for "int rinsic" drop breakage and coalescence rates, a multiblock model for the sti rred tank is needed in parameter estimation as well. The stirred tank flow model may be obtained from measurements or from computational fluid dynamic s simulations in a straightforward manner. (C) 1999 Elsevier Science Ltd. A ll rights reserved.