涡状线进料体旋流器分离性能的数值分析

Numerical analysis of the separation performance of vortex feed hydrocyclone

合理的进料体结构是提高旋流器分离性能的重要途径,它不仅可以对颗粒起到引导和加速的作用,而且可以实现颗粒的预分离。但是,直到现在也没有确切的理想进料体控制方程。传统旋流器采用单一直线式结构,该结构虽然加工简单,但是能量损失大,短路流现象严重。为了克服传统进料体的缺点,本文提出一种涡状线进料体结构形式,能有效提高旋流器的分离性能。通过CFD数值分析得出数据,并与经典旋流器进行了数值比较,验证了数值模拟的准确性。主要有以下发现:涡状线进料体可以使得压力降和切向速度都增加,有效地减少了错位粒子的数量。涡状线进料体内旋流的轴向速度较小,这使得细颗粒停留时间更长,分离更彻底。涡状线进料体还可以有效地减少短路流量。涡状线进料体湍流黏度更小,减少涡流发生概率,使颗粒运动更加平稳。涡状线进料体可以使切割粒径从12.5μm减少到8.17μm,而且陡度指数从0.33增加到0.47,因此采用涡状线进料体可以获得更细和更高质量的产品。

Reasonable feed structure is an important way to improve the separation performance of hydrocyclone.t not only can guide and accelerate the particles,but also can achieve the pre-separation of particles.However,till now,here is no exact ideal feed body control equation.The traditional hydrocyclone adopts a single straight-line structure.Although the structure is simple to process,it has a large energy loss and a serious short-circuit flow in order to overcome the shortcomings of the traditional feed body,this paper proposes a vortex line feed body structure,which can effectively improve the separation performance of the hydrocyclone.Through the data obtained by CFD numerical analysis,and comparing the data with the classical hydrocyclone,he accuracy of the numerical simulation is verified.It is found that the vortex line feed body can increase both the pressure drop and tangential velocity,and effectively reduce the number of dislocated particles.The axial velocity of swirling flow in the vortex line feed body is smaller,which makes the retention time of fine particles longer and the separation more thorough.The vortex line feed body can also effectively reduce the short-circuit flow,making the turbulent viscosity smaller,educing the occurrence probability of vortex,and making the particle movement more stable.The vortex line feed body can reduce the cutting particle size from 12.5μm to 8.17μm,and the steepness index increases from 0.33 to 0.47.Therefore,using the vortex line feed body can obtain finer and higher quality products.