Sedimentation and Coalescence Profiles in Liquid-Liquid Batch Settling Experiments



A simple mathematical method for predicting the phase separation profiles of a batch liquid-liquid dispersion is developed based on the empirical description of drops resting at a liquid-liquid plane interface. The inflexion time, at which the sedimentation zone vanishes, can be obtained by analysis of the coalescence profile. Therefore, the sedimentation profile can be predicted and the size of drop and interfacial area can be estimated. The experiments were carried out with an O/W-type dispersion of kerosene-water system in a 154 mm I.D. mixing vessel. The experimental results agree well with the model prediction. Other experimental data in the literature were also adopted for testing the model.