改进Intermig桨种分槽搅拌性能的数值模拟

Numerical Simulation of Mixing Performance in Seed Precipitation Tank with an Improved Intermig Impeller

利用商业CFD软件Fluent12.0和并行计算系统图形工作站,对改进的Intermig桨种分槽内部流场进行了三维数值解析.采用Realizablekε湍流模型和欧拉欧拉多相流模型对槽内不同桨叶离底距离C、桨叶直径D下的氢氧化铝颗粒悬浮规律以及搅拌桨功率消耗进行了模拟.结果显示,搅拌转速一定的条件下,桨叶直径越大,越有利于颗粒悬浮,搅拌功率越大;相对最佳桨径与槽径比为0.6;过高和过低的桨叶离底距离都不利于氢氧化铝颗粒悬浮,桨叶离底距离对功率影响较小,相对最佳离底距离与桨径比为0.55.

Seed precipitation tank with a new-style improved Intermig impeller was numerically simulated by using the commercial software Fluent 12.0 on parallel computing graphic workstation.The suspension of Al（OH）3 particles and power consumption in the alumina seed precipitator under different conditions of the impeller off-bottom clearance height （C） and blade diameter （D） were numerically simulated by using realizable k-ε turbulence,Eulerian Eulerian multiphase and multi-reference frame rotating models.The numerical simulation results showed that at a constant rotate speed,enlarging D was good for suspension of Al（OH）3 particles,but bigger D resulted in more power consumption.The optimal value of D/T was 0.6,T was the tank diameter.Too big or too small C was not conducive to the suspension of Al（OH）3 particles,and C had little effect on the stirring power.The optimal value of C/D was 0.55.