Drawdown of Floating Solid in Mixing Vessel with Inside Baffle

Abstract

An inside baffle which was placed inside a vessel with a clearance between the baffle and the vessel wall has been developed to draw down the floating solids into the liquid effectively. The drawdown performance of floating solids into the liquid was investigated under four baffle conditions: no baffle condition, standard baffle condition, surface baffle on the wall condition, and inside surface baffle condition. The minimum impeller rotational speed for the complete suspension of floating solid N_JD was measured visually under all the baffle conditions. Particle image velocimetry (PIV) was conducted to measure the velocity field. The volumetric power consumption P_{V, JD} at N_JD, was measured. As a result, N_JD under the inside surface baffle condition was the lowest at an impeller position near the vessel bottom. Moreover, P_{V, JD} under the inside surface baffle condition was the lowest among all the baffle conditions at all impeller positions.