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The effects of baffle configuration, impeller type, impeller diameter ratio, and immersion depth on the critical drawdown speed and power of floating particles were investigated by experiment, and the advantageous stirred vessel was determined on the basis of the low energy consumption principle. Furthermore, the effects of system viscosity, mean solid concentration, and particle size on the dispersing characteristic of floating particles were also researched with the advantageous stirred vessel. The results show that, (1) when the stirred vessel is equipped with a single baffle, the critical drawdown speed and power of floating particles are lower than those of others. (2) Among the propeller, six flat‐blade disc turbine (Rushton), and six 45° pitched‐blade turbine (PBT‐6), the Rushton turbine has the lowest critical drawdown speed, and the down‐pumping propeller (TXL) has the lowest critical drawdown power. (3) The critical drawdown speed and power are lower with a larger impeller diameter and a smaller immersion depth. (4) The critical drawdown speed and power increase with increasing system viscosity, mean solid concentration, and particle size. The experimental results provide useful guidelines for the advantageous design of the stirred vessel used for the dispersing of floating particles in a viscous system.

Based on the Gidaspow model, the distributions of velocity, turbulence intensity, and solid concentration in stirred vessels equipped with a down-pumping propeller (TXL), a six flat-blade disc turbine (Rushton), or a downpumping six 45° pitched-blade turbine (PBTD-6) in a viscous system were simulated. The power curve of the TXL propeller and the dimensionless solid concentrations of one sampling point in the vessel at different agitation speeds were obtained by simulation and experiment, which were in good agreement with each other. The results showed that: (1) both the tangential velocity and turbulence intensity on the liquid surface caused by a Rushton turbine were the highest of the three conditions at the same agitation speed; (2) the turbulence intensity on the azimuth of 90° behind the baffle near the shaft on the liquid surface was relatively larger than that in other regions; (3) the uniformity of solid concentration distribution in the stirred vessel equipped with a Rushton or PBTD-6 turbine was better than that with a TXL impeller at the same agitation speed.