The effect of some geometric factors, namely, draft tube diameter and entrainment height was investigated by the two-fluid model (TFM) applying the kinetic theory of granular flow. The model proposed was found to be in a good agreement with the experimental measurements in a wide range of gas velocities and different draft tube diameters as well as entrainment heights. The influence of particle-wall restitution coefficient in the small and large draft tube diameters was examined. Accordingly, different values of ew were evaluated in the draft tubes. It was observed that the model predictions for particle behaviour through the small draft tube are sensitive to the values of ew, while the sensitivity declines and disappears for large draft tube. The particle behaviour for various geometric factors was predicted by the model.
