基于CFD的卧式螺带混合机的混合过程分析

Mixing Process Analysis of Horizontal Ribbon Mixer Based on CFD

针对目前粉体混合研究中试验方法在三维流场的局限性,利用流体动力学软件FLUENT模拟了卧式螺带混合机的三维流场。通过简化建立了混合机三维模型,选择标准k-ε湍流模型及混合多相流模型对混合机内部流动进行仿真,选择输运模型计算示踪剂浓度。同时,重点分析了速度分布云图和体积分布云图,验证了物料在内外螺带区域的轴向和径向速度方向均相反,且物料在外螺带区域速度>内螺带区域速度,通过体积分布云图可方便监测物料瞬态分布状态。通过分析示踪剂的质量分数变化,得出了经过55s物料即可混合均匀,验证了该混合机的高效率,该研究结果为进一步改进混合机性能提供了理论依据。

In the current study of powder mixing , there are some limitations of test method in three-dimensional flow field.This paper uses fluid dynamics software FLUENT to simulate the flow field of horizontal ribbon mixer .Through sim-plified the three-dimensional mixer model ,select the standard k -ε turbulence model and mixture model to simulate the internal flow of the mixer , select transport model to calculate the tracer concentration .From the velocity contours and vol-ume distribution cloud , it verifies that the material axial and radial velocity in the outer and inner ribbon regions are op-posite , and the speed in the outer spiral band area region is faster than inner ribbon reigon .By volume distribution it is easy to monitor the transient distribution of the material .Through analyzing the change of the mass fraction of tracer , it can be obtained in about 55 s to mix evenly which verify the high efficiency of the mixer .The research provides a theoreti-cal basis to improve the performance mixer in the further study .