The effect of distributor configuration on the hydrodynamics of the teetered bed separator

Abstract

The teetered bed separator (TBS) is a gravity concentration device which operates on the principle of hindered settling. The hydrodynamics of the separator and fundamental particle interactions in the teeter bed were investigated for a two phase liquid–solid system with the coal particles of a wide size and density distribution considered as multiple solid phases. Seven distributor plates of varying aperture size and geometric arrangement were considered. The flow behaviour was predicted using the Multiphase Eulerian and Mixture Model in the commercial CFD package, Fluent 6.1. The simulations gave an indication of the dead zones, turbulent regions, wall effects and the specific flow pattern due to each plate. The model may be used to predict the most appropriate distributor configuration for the separation process based on the flow patterns and particle interactions in the unit. A laboratory scale TBS was constructed to investigate the separations achievable using the simulated designs. Coal particles sized between 2 and 0.038 mm with a specific gravity (SG) range of 1.2–2.0 were used as the material to separate. Partition curves were plotted for the separations carried out under modeled conditions and the Ecart probable ( E p) and cut point density ( D 50) obtained. The simulations and experimental testwork indicated that Plate 3 may be the most appropriate distributor configuration for the investigated conditions due to the even velocity profile with minimum flow disturbances experienced in the coal separation process.