重选设备搅拌器优化设计中Fluent的应用

Application of Fluent Software to the Optimal Design of Agitator in Gravity Separator

针对铝土矿资源特点,设计了一种适合铝土矿预分选脱硅的重选设备。在确定了最佳的工艺参数基础上,对其中的关键部件搅拌器进行了优化设计。利用GAMBIT构造三维实体模型和网格划分。基于有限体积法和标准湍流模型,利用CFD数值模拟软件Fluent和多重参考系(MRF)法,通过求解雷诺时均化的Navier-Stokes方程,对不同搅拌器的流场进行数值模拟。结果表明,搅拌器叶臂倾角的增大,不能有效地改善铝、硅相分布的均匀性。平臂搅拌器随着齿高度的增加,壁面处的湍动强度变化梯度逐渐减小,设备中的湍动强度趋向于均匀,沉砂的铝硅比提高幅度较大,而其产率和氧化铝的回收率只有小幅度的下降。实际矿石分选试验验证了Fluent数值模拟指导搅拌器设计的可行性。

According to the properties of bauxite, a new gravity separator for silicates removal from bauxite has been designed for the pre-separation of bauxite. Based on the determination of optimal process parameters, the agitator, the key component of the gravity separator, was optimized. The software of GAMBIT was used to establish the three-dimensional entity model and grid generation. Based on standard turbulence model and FVM （Finite Volume Method）, combined with three-dimensional incompressible reynolds-averaged navier-stokes equations, MRF （Multiple Reference Frame）, the flow field inside the equipment were simulated with CFD（computational fluid dynamics） numerical software Fluent for different agitators. The results show that the increase of arm incline angle of agitator can not improve the distribution difference of alumina and silica. With the increase of horizontal agitator tooth depth, the turbulence intensity change gradient on the surface reduced gradually and the turbulence intensity tended to be even, and the ratio of Al/Si of underflow was improved greatly. but there was only a small decline of the yield ratio and Al2O3 recovery. Actual ore separation experiments verified the feasibility that Fluent numerical simulation can be used to design agitators.