Gas‐solid flow in vertical tubes

A computational study of fully‐developed flow of gas‐particle suspensions in vertical pipes was carried out, using the model proposed recently by Sinclair and Jackson (1989), to understand the predicted scale‐up characteristics. It was shown that the model can capture the existence of steady‐state multiplicity wherein different pressure gradients can be obtained for the same gas and solids fluxes. A pronounced and nonmonotonic variation of the pressure gradient required to achieve desired fluxes of solid and gas with tube diameter was predicted by the model, and this is explained on a physical basis. The computed results were compared with the experimental data. The model manifests an unsatisfactory degree of sensitivity to the inelasticity of the particle‐particle collisions and the damping of particle‐phase fluctuating motion by the gas.