关键词: 大双叶片搅拌器, 宽适应性, 功率消耗, 混合特性, 数值模拟

Abstract: Considering the complexity and variation of mixed system in many processes in industry,a novel large-double-blade impeller with wide adaptability was developed.A computational fluid dynamics model describing the flow and mixing process was built,and the power,flow field and mixing characteristics in a stirring tank equipped with the novel impeller were simulated and analyzed.The simulation results show that in the flow field produced by the novel impeller,there are local circulating flows in the upper and lower blade zone and overall circulating flow through the whole tank.As the viscosity of mixing system increases,the fluctuations of axial,radial and tangential velocities in the flow field decrease,and its power and mixing performance remain good,which indicate that the novel impeller has a wide adaptability to flow regimes and viscosities.For the novel large-double-blade impeller,it is not beneficial to the global mixing when the feeding point is located close to liquid surface,so the feeding between the upper and lower blades is recommended in order to shorten the mixing time.The novel impeller is more efficient than the FZ impeller with the same dimension under the same power consumption per unit volume,so it is more competitive in energy conservation.The simulation will contribute a lot to the improvement and optimization of the structure and operation of the novel large-double-blade impeller.

Key words: large-double-blade impeller, wide adaptability, power consumption, mixing characteristics, numerical simulation