Effect of Suspension Pattern of Sedimentary Particles on Solid/Liquid Mass Transfer in a Mechanically Stirred Vessel

The solid/liquid mass transfer rate of particles stagnation on vessel bottom and partial suspension in liquid was insufficiently known compared with that of completely suspended condition. In this study, the effect of suspension regime of sedimentary particles on the solid/liquid mass transfer rate in a mechanically stirred vessel without baffles was investigated. The solid/liquid mass transfer rate increased slightly with the increasing rotation speed at the stagnation regime; its rapid enhancement was found at the partially suspended regime, and the increasing rate became slow again at the complete suspension. Nondimensional equations for solid/liquid mass transfer rate of stagnation and completely suspended conditions were obtained with a good correlation. On the other hand, the suspended particle ratio under the partial suspension condition was estimated by the mass transfer rate of stagnation and completely suspended regimes and followed an S curve against the normalized rotation speed.