FACTORS AFFECTING THE DECAY OF BATCH LIQUID LIQUID DISPERSIONS

A model which predicts the shape of the time dependent sedimentation and coalescence profiles during batch decay, allowing for binary coalescence and increasing hold-up in the sedimentation zone, and the effect of the height of the dense-packed zone on the interfacial coalescence rate, is presented. The model is verified using the experimentally observed increase in drop size with time. Analysis of twenty five liquid-liquid systems covering a wide range of physical properties, operating conditions and settler geometry indicates that sigmoidal or exponential sedimentation profiles are obtained depending on whether the initial Reynolds number is less or greater than unity, respectively.