Applicability of the power model to mixed slurries with non-spherical particles and networking effect


CHEMICAL ENGINEERING RESEARCH & DESIGN, vol.138, pp.314-330, 2018 (SCI-Expanded) identifier identifier


Industrial applications of solids suspension generally consist of mixed slurries that contain many solid phases with irregularly shaped particles at high concentrations. Since solid-liquid mixing is a power intensive operation it is critical to predict the just suspended speed, N-j(s), accurately. There is only one model available for mixed slurry N-js predictions: the power model. This model was developed for spherical particles. In this study, suspension behaviour of mixed slurries with non-spherical particles was investigated. It was seen that the presence of non-spherical particles decreases N-j(s), but the power model is still applicable. The original limits of applicability of the power model is for spherical particles and up to 27 wt% solids concentration, without networking mechanism. The networking mechanism is seen when the small and less dense particles significantly ease the suspension of larger and denser particles in the slurry. In this study, a correction factor to the power model was recommended to account for the networking mechanism. The power model can now be applied to mixed slurries of any shape of particles up to 55 wt% solids, with or without networking mechanism. The effect of shape was also investigated for unimodal slurries, but no significant deviation was found in the predictions. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.