入口形状对旋风分离器性能的影响

为了研究入口形状对旋风分离器性能的影响,采用计算流体力学(CFD)软件对旋风分离器的压力场和颗粒的分离情况进行考察。研究结果表明:入口形状会显著影响旋风分离器的压降,在圆形、矩形、三角形和等腰梯形几种不同的入口形式中,长宽比为2的矩形入口压降最大,长宽比为1.5的矩形入口的压降最低;对于矩形入口,随着长宽比的增大,压降是先降低再升高;入口形状对粒径大于2.5μm粒子的分级效率影响不大,当粒径小于2.5μm时,圆形入口的分离效率最差,梯形入口的分离效率最好;梯形入口会改善旋风分离器顶部流场和灰斗附近流场,使颗粒运行平稳,分离效率较高。

Effects of Inlet Shape on the Performance of Cyclone

In order to study the effects of inlet shapes on the performance of cyclone,computational fluid dynamics(CFD) code was used to analysis the pressure field and the separation performance of different size particles in the cyclone.The results show that:(1) Inlet shapes will significantly affect the cyclone pressure drop.In the six cases of different inlet shapes,the rectangular inlet with aspect ratio of 2 has the greatest pressure drop and the one with aspect ratio of 1.5 has the lowest.(2) For the rectangular inlet,with the aspect ratio increases,the drop will decrease at the beginning and then increase.(3) Inlet shapes can’t significantly affect the grade efficiency of particles larger than 2.5 μm.While the particles’ size is smaller than 2.5 μm,the cyclone with circular inlet has the worst performance and the trapezoidal one has the best performance.(4) The trapezoidal inlet will significantly improve the flow field at the top of cyclone and around the ash bucket,which can make the particles run more smoothly and get higher separation efficiency.