AN IMPROVED METHOD FOR PREDICTING SOLIDS CONCENTRATION PROFILES IN SLURRY FLOW THROUGH PIPELINE, RECTANGULAR DUCT AND OPEN CHANNEL

摘要

The experimental data reported in literature were compared with the predictions by Karabelas (9) model for solids concentration profiles in the slurry flow of a variety of materials through a pipe, a rectangular duct and an open channel with wide range of flow velocities and efflux concentrations of solids. The Karabelas model was found to be able to predict reasonably accurately at lower efflux concentrations, however it failed to predict the solids concentration profiles accurately at higher levels of efflux concentrations. Modifications were proposed in the Karabelas model to remove the deficiencies by alleviating some of its restrictive assumptions. In particular, the effects of local concentration on the particle settling was considered, and particle diffusivity was taken as variable with local concentration and particle size. The modified model predicted the solids concentration profiles with reasonable accuracy in all the three geometries for the entire range of efflux concentration and flow velocity considered in the present study.