不同组合桨搅拌器搅拌特性的数值研究

Numerical Study of Mixing Characteristics in Stirred Tanks with Different Impeller Combinations

采用Fluent软件的多重参考系(MRF)及标准k-ε湍流模型,针对双层平直桨叶、双层45°折叶涡轮桨和两者组合搅拌桨这3种搅拌桨,研究了不同桨叶类型搅拌槽内的流动混合特性和加料位置,结果表明:45°折叶涡轮桨和平直叶桨的上下组合桨可以增强搅拌器内流体的上下湍动,促进混合,其搅拌功率较双层平直叶桨下降37.91%,混合时间减少50.48%;选择上层桨叶尖端加料可以缩短搅拌器内液体的混合时间,提高搅拌效率.

In this paper,the multi-reference frame（MRF） and standard k-e turbulent model were used to simulate the flow pattern and mixing characteristics in the stirred tanks with double layer straight impeller, double 45° inclined impeller and double layer straight and inclined combined impeller. The results showed that double layer combined impeller can enhance the turbulence and mixing of the upper fluid and lower one in the stirred tank. Moreover, compared with the double layer straight impeller, double layer combined impeller can save 37.91% of stirring power and reduce 50.48% of mixing time. Furthermore, compared with the feed- ing patterns from the fluid surface and the lower blade, the feeding pattern from the upper blade can obviously save the mixing time and improve the efficiency of mixing.