三层搅拌桨排列方式对流场影响的数值研究

Numerical Study of Effect of Marshalling Styles of Three - Layer Impellers on Flow Field

为了对在役聚苯乙烯反应装置的反应器进行优化设计和结构改进,利用计算流体力学方法(CFD)分析了在役反应器内物料的非稳态流动情况,计算了反应器内物料流动的宏观速度场和分析线的速度分布,研究了三层搅拌桨3种排列角对物料流动特性的影响。结果表明,在役聚苯乙烯反应器(三层搅拌桨排列角为0°)内物料的流动以周向流动为主,下层搅拌桨附近物料的径向混合效果好于上层搅拌桨附近的物料。由于受到上下桨叶的干扰,三层搅拌桨之间形成的循环涡流区受到抑制,涡流区面积较小。综合比较发现:排列角为120°的三层搅拌桨混合效果最好,其次是排列角为90°的三层搅拌桨,而搅拌桨排列角为0°的反应器的混合效果最差。

In order to optimize device and improve structure of in service polystyrene reactor, non - steady flow field of material was analyzed by means of CFD method. Material flow＇ s macroscopic velocity field and analytic lines＇ velocity distributing in the reactor were calculated. Effect of three kinds of marshalling angles of three - layer impellers on flow characteristics of materiel was studied. The results show that materiel flows mainly along periphery direction in in - service polystyrene reactor （marshalling angle with three - layer impellers is zero degree） and the material mixed effect of lower layer along radial direction is better than upper one. Due to the interference of up and down blades, the circular vortex area in three- layer impellers is restrained and the area of vortex is small. By synthetic comparison, the mixed effect of three- layer impellers with marshalling angle of 120 degree is the best in three models, the marshalling angle of 90 degree is second and the mixed effect of in - service polystyrene reactor with marshalling angle of zero degree is the least of all.