入口结构对旋风分离器性能的影响

Impact of the inlet structure on the performance of the cyclone separator

为探究入口结构对旋风分离器分离效率的影响,选用Fluent模拟软件中雷诺应力模型和离散相模型对3种不同入口结构旋风分离器两相流流场进行数值模拟研究。结果表明:对称双入口结构三维速度分布和静压分布具有较好的对称性,可有效抑制涡旋尾端摆尾而引起的壁面颗粒卷吸,有利于颗粒分离;引入新风的同侧双入口结构内清洁空气对颗粒具有挤压作用,趋使颗粒向壁面运动,可有效改善排气管底部短路流。2种改进入口结构与切向单入口结构相比总分离效率分别增加8.44%和10.88%。

The given paper is inclined to explore the impact of the inlet structure on the separation performance of the cyclone separator,while it intends to adopt the Reynolds Stress Model and the Discrete Phase Model in the Fluent software to simulate numerically the two-phase flow field of the cyclone separator with the 3 different inlet structures. And,for the given purpose,we have managed to take into account the dual-phase coupling between the gas and the solid phases in the numerical simulation,with the random trajectory model taken in the particle motion solution process. And,in the above said particle motion solution process,the accuracy of the numerical simulation model can be verified by the experimental data in the existing literature. Thus,it can be seen from the numerical simulation results of the cyclones with different inlet structures that the tangential velocity is a Rankine combined vortex distribution. And,in the cyclones with the different inlet structures,the symmetrical double inlet structure is supposed to have a largest tangential velocity component,whereas the same side double inlet structure is the second with a tangential single inlet structure being smaller. On the other hand,the axial velocity distribution of the three may have merely little difference,with no obvious change in the upstream and downstream distribution areas. On the other hand,the single-inlet structure ought to have the largest radial velocity component,a double entrance structure on the same side followed,with its symmetrical double-inlet structure tending to have a flat radial velocity. Thus,the smaller the radial velocity,the less the drag force on the particles,which can be conducive to the movement of the particles to the wall. And,then,since the flow field and the pressure field in the symmetrical double inlet structure are to be structurally in nice symmetry,it can effectively suppress the wall particle entrainment cause by the tail end of the vortex,which can also be conducive to the particle separation.And,in such a particular manner,the clean air in the double-inlet structure on the same side can introduce the fresh moving air into a squeezing effect on the particles,which tend to move along in the wall direction so as to improve effectively the short-circuit flow at the bottom of the exhaust pipe. And,in such a manner,as compared with the tangential single inlet structure,the total separation efficiency can be made to increase by 8. 44% and 10. 88%,respectively and correspondingly.