Modelling solid-liquid separation and particle size classification in decanter centrifuges

Abstract

Decanter centrifuges or solid bowl centrifuges (SBCs) are widely used in separation applications ranging from solid-liquid separation to the classification of ultrafine particles. Several models have been developed by others to describe the solid-liquid separation process in the SBC and to predict the separation efficiency (solids recovery). These models cannot, however, provide detailed information on particle size classification in the SBC, mainly resulting from the neglect of the liquid backflow (in the direction away from effluent discharge point) near the sediments within the SBC and the disregard for different drag regimes. The present work addresses these issues. A physical model without any adjustable parameters was developed to predict solid-liquid separation and particle size classification in the SBC. The model predictions are in good agreement with published experimental data.