锥角对水力旋流器流场及分离性能影响的数值试验研究

为了考察锥角对水力旋流器内部流场和分离性能的影响,针对实验室Φ50 mm水力旋流器,采用Fluent软件中RSM湍流模型、VOF和Mixture多相流模型进行了系统的数值试验研究。流场模拟结果表明,在相同操作条件下,增大锥角,空气柱直径增大,湍流强度增加,压强和压强梯度均明显增加,从而导致整体能耗增加;切向速度随锥角增大明显升高,轴向速度变化不大,但LZVV逐渐向器壁移动,分流比逐渐降低。颗粒分离模拟结果表明,增大锥角会导致分离粒度增加,各粒级分离效率降低;小锥角容易造成"底流夹细"现象,大锥角容易引起"溢流跑粗"现象。研究结果为水力旋流器锥体的结构选择和设计提供了参考。

Effects of Cone Angle on the Flow Field and Separation Performance of Hydrocyclones

In order to investigate the effects of cone angle on the flow field and separation performance of hydrocyclone,a systematical numerical study on a laboratory Φ50 mm hydrocyclone were conducted by using the RSM turbulence model,VOF and Mixture multiphase flow model by Fluent software. The flow field simulation results show that under the same operating conditions,with cone angle increasing,the air core diameter,turbulence intensity,pressure and pressure gradients are significantly increased,resulting in an increase in overall energy consumption. The tangential velocity also increases with the increase of cone angle,but the axial velocity does not change obviously. However,the LZVV gradually moves toward the wall,and the split ratio decreases subsequently. The simulation results of particle separation show that increasing the cone angle leads to an increase in the cut-size and a decrease in the separation efficiency for each size fraction.In addition,a small cone angle is likely to increase the misplacement of fine particles in underflow,while a large cone angle might enhance the entrainment of coarse particles in overflow. The results provide a reference for the selection and design of the conical structure of hydrocyclones.