An effective voidage model for sedimentation of bidisperse solid suspension

An effective voidage model of a liquid-fluidized bed that takes into account particle–particle interaction has been used to predict the slip and interface velocities of sedimenting zones for bidisperse solid–liquid systems. The model visualizes that a ‘test particle’ in the bed is surrounded by particles of ‘average size’ but enjoys an effective voidage different from the average voidage. The model was successfully used before to interpret and predict phase inversion as well as mixing and segregation in a liquid-fluidized bed. A little modification of the original model was done to make it suitable for interpreting batch sedimentation data. The model does not necessarily need the experimental values of the relevant parameters. Predictions of the model over a range of particle sizes and liquid properties are more accurate than those of the previous models.