Dense solid-liquid off-bottom suspension dynamics: Simulation and experiment

Dense solid-liquid off-bottom suspension inside a baffled mechanically stirred tank equipped with a standard Rushton turbine is investigated. Dynamic evolution of the suspension from start-up to steady-state conditions has been determined by both visual experiments and computational fluid dynamics (CFDs). A classical Eulerian-Eulerian multifluid model (MFM) along with the “homogeneous” k-ɛ turbulence model is adopted to simulate suspension dynamics. In these systems the drag inter-phase force affects both solids suspension and distribution. Therefore, different computational approaches are tested in order to compute this term. Simulation results are compared with images obtained from the real system and a good agreement is found. The soundness of the proposed approach is further validated by comparing predicted concentration profiles with literature data for the case of a similar geometry.