稳涡内构件对旋风分离器内流场和性能的影响

Effect of Installation of Apex Cone on Flow Field and Performance in Cyclone Separator

旋进涡核现象会削弱旋风分离器对细颗粒的捕集效率。利用数值模拟方法研究了在排尘口处安放圆锥型稳涡部件对旋风分离器内流场及性能的影响。首先分析了圆锥对旋风分离器内的速度分布、短路流量、涡核旋转特性的影响,在此基础上统计了分离器对1μm颗粒的捕集效率,随短路流逃逸和因气流夹带而返混逃逸的颗粒比例。结果表明:圆锥的加入既能够降低旋进涡核的频率,又能抑制涡核偏离分离器几何中心的程度,从而减弱了因涡核尾端在排尘口附近的扫壁现象而造成的颗粒返混逃逸。因此,圆锥这一稳涡内构件能够有效提升分离器捕集效率。另外,它对旋风分离器主要分离空间内气流的切向速度、轴向速度和短路流等的影响不大,因而压降没有明显增加。

The precession vortex core weakens the trapping efficiency of cyclone to fine particles.In this paper,numerical simulation method was used to investigate the influence of apex cone placed at the dust outlet on the flow field and performance of cyclone.First,the influence of apex cone on the velocity distribution,shortcircuit flow and vortex cone procession characteristics in cyclone separator was analyzed.On this basis,the trapping efficiency for 1μm particles and the proportion of particles that escaped with shortcircuit flow and back-mixing due to air entrainment were measured.The results show that the installation of apex cone can reduce the procession frequency and deviation of vortex core,thus weakening the particles escape caused by the end of the vortex core sweeping wall of cyclone.Therefore,the installation of apex cone can effectively improve the separation efficiency of cyclone separator.In addition,the installation of apex cone has little effect on the tangential velocity,axial velocity and shortcircuit flow of the airflow in the main separation space of cyclone,and thus the pressure drop is not significantly increased.