Prediction of bed voidage in particulate and aggregative solid-liquid fluidization

Accurate prediction of bed voidage is essential for the calculation of liquid side transfer coefficients in solid-liquid fluidized bed systems. A hydrodynamic model is used to predict the onset of aggregation in the fluidized bed systems. The bed voidage in the particulate and in the transition zone from particulate to aggregate fluidization is a strong function of particle size and density, while in aggregative fluidization the bed voidage is almost independent of the solid phase physical properties. The Hirata and Bulos correlation for the prediction of the bed voidage is fitted for the cases of particulate and aggregative fluidization The modified model predicts the present data and previously published data by other investigators with excellent accuracy.