氟钽酸钾钠还原搅拌釜中的搅拌流场数值模拟

Numerical Simulation of Stirring Flow Field in Stirred Tank for Potassium Fluotantalate Sodium Reduction

采用标准k-ε湍流模型、Eluer-Eluer双流体模型,结合滑移网格法,对氟钽酸钾钠还原搅拌釜中搅拌流场进行数值模拟,研究不同转速、搅拌桨叶类型对液钠-熔盐分散特性、流场的影响。结果表明,在两种桨叶模型下,液钠仅局部分布在混合熔盐表面;平直叶桨、折叶桨搅拌均在搅拌釜内形成四个循环流区域,且在搅拌轴附近区域存在搅拌死区;液钠在液面的分散面积均随着转速的增加而减小,沿搅拌轴进入熔盐的深度随转速的增加而增大;在折叶桨模型下,随着搅拌转速的增加,近液面处流场速度增大,速度沿X轴方向呈对称分布。

The stirring flow field in stirred tank for potassium fluotantalate sodium reduction was simulated by standard k-ε turbulent model, Eluer-Eluer model and sliding grid method based on FLUENT software.Effects of different rotational speeds and types of impeller on dispersion characteristics and flow field of liquid sodium-molten salt were studied.The simulation research shows that for the adopted two types of impeller, the liquid sodium is only locally distributed on surface of mixed molten salt.Both the straight-blade impeller and folded-blade impeller induce four circulating flow areas in stirring tank, and there is a stirring dead zone in the area near stirring shaft.The dispersion area of liquid sodium in liquid surface drops with the increase of rotation speed, and the depth of molten salt along stirring shaft rises with the increase of speed.Under the folding propeller model, with the increase of impeller rotation speed, the velocity of flow near liquid surface rises, and the velocity is symmetrically distributed along the X-axis direction when using the folded-blade impeller.