平底结构对水力旋流器流场特性及分离性能影响

基于数值模拟对比了渐缩平底旋流器与复合锥角旋流器流场特性以探究平底结构对水力旋流器流场的影响。数值试验结果表明：两种水力旋流器压强分布和切向速度分布基本一致,而空气柱附近压强梯度存在差异；渐缩平底旋流器溢流管下方湍流强度较低而底流口附近则相反；渐缩平底旋流器柱-锥交界面的空气柱附近轴向速度较高,导致其分流比较低。实验室旋流分离试验表明：平底结构能有有效抑制溢流跑粗和底流夹细现象,显著提高分级效率,改善水力旋流器分离性能。

Effect of flat bottom structure on flow field characteristics and separation performance of hydrocyclone

Based on numerical simulation, the flow field characteristics of the contract gradual flat bottom hydrocyclone and the multi cone hydrocyclone were compared to explore the effect of flat bottom structure on the flow field of hydrocyclones. Numerical results show that the pressure distribution and tangential velocity distribution of the two hydrocyclones are basically the same, but the pressure gradient in the vicinity of the air core is different. The turbulence intensity under the vortex finder of the contract gradual flat bottom hydrocyclone is relatively low, while the turbulence intensity near the spigot is the opposite. The axial velocity near the air core at the cylindrical - cone interface of the contract gradual flat bottom is higher, resulting in a low split ratio of hydrocyclone. The laboratory cyclone separation test shows that the flat bottom structure can effectively suppress the phenomenon of coarse particles misplaced in the overflow and fine particles misplaced in the underflow, and significantly improve the classification efficiency, thereby improving the separation performance of the hydrocyclone.