In order to study the mixing effect of flow and analyze the flow pattern as well as the velocity characteristics in high shear pulp pump, a geometrical hydraulic model of a high shear pulp pumps was established by Pro/E, and solidliquid twophase flow in it was simulated by using the CFD method based on the mixture model, standard k-ε turbulence model and SIMPLEC algorithm. The meshindependence check was conducted to reduce the influence of mesh size on the results.A series of CFD numerical simulations were carried out under different discharges and rotational speeds, respectively, and the results were compared among the cases to identify their influence on the flow field in the pump. The results show that the mixing uniformity of two phases was improved considerably after the solid phase was sheared in the shearing chamber, suggesting the shear pulp pump exhibited a better mixing and homogenizing effect for the solid phase in flow. The rate of two phases mixing becomes slow when the discharge is increased, and the mixing rate and uniformity of two phases are improved when the rotational speed increases.Note that the mixing rate and uniformity of two phases in the impeller but those in the inlet to the impeller are affected in a great deal by a change in the rotational speed.
YE Xiao-Yan,TIAN Ying-Ying,DING Ya-Na et al. Numerical simulation of twophase flow in high shear pulp pump[J]. Journal of Drainage and Irrigation Machinery Engin, 2012, 30(4): 407-411.
Chitu T M, Oulahna D, Hemati M. Wet granulation in laboratoryscale high shear mixers: Effect of chopper presence, design and impeller speed[J]. Powder Technology, 2011,206（1/2）: 34-43.Bukovec P, Kroselj V, Turk S,et al. Optimization of melt pelletization in a high shear mixer[J]. International Journal of Pharmaceutics, 2009,381（2）: 192-198.
Zhou Fuqiang, Zhou Leilei. Study on structure mechanism, flow field and power for continuous high shear homogenizer[J]. Food and Machinery, 2009, 25(1):97-100.(in Chinese)
Khopkar A R, Tanguy P A. CFD simulation of gasliquid flows in stirred vessel equipped with dual rushton turbines: Influence of paralle, imerging and diverging flow configurations[J]. Chemical Engineering Science, 2008,63 (14): 3810-3820.