Prediction of drop sizes for liquid–liquid systems in stirred slim reactors—Part I: Single stage impellers

Abstract

Although investigations in the field of stirred liquid/liquid dispersions have a long history, new questions are still emerging in dealing with the different aspects of industrial applications, such as suspension polymerizations. In this study the influence of physical parameters on drop size and power consumption, like liquid level, stirrer speed, stirrer height and baffle length, were experimentally analyzed. The results were used to determine modeling approaches which are capable of displaying the influence of the named parameters. It was shown that the energy law ( d p ∼ ɛ −0.4; Shinnar, 1961 [1]) using the average energy dissipation only roughly predicts the Sauter mean diameter. The population balance equation (PBE) used with a one-zone modeling approach is slightly better in its prediction of results. Very satisfying predictions were obtained by using the PBE with a two-zone model. The overall deviations between calculated and predicted Sauter mean diameter was less than 10% using this approach. Only the successful prediction of the influence of the baffle length remained unattainable, even with the PBE two-zone model.