导叶式旋风管内短路流颗粒夹带的研究

Study on Particles Entrainment by Short-circuit Flow in Guide Vane Cyclone Tube

采用数值模拟方法,结合试验与理论分析,研究Shell型导叶式旋风管内短路流颗粒夹带问题。结果表明:Shell型旋风管直筒芯管下口存在短路流现象,计算得知短路流量占进口总流量的39.3%。理论分析发现,短路流主要夹带粒径小于9μm的颗粒,短路流夹带颗粒临界粒径为9μm。另外,数值模拟跟踪颗粒逃逸的轨迹证明,Shell型旋风管能将粒径大于9μm的颗粒全部除尽;粒径小于9μm的颗粒既有经排尘口返混逃逸,又有短路流夹带逃逸,其中短路流夹带逃逸占主要部分,且随着粒径的增加,经芯管下口短路夹带逃逸的数目减小。

Based on the numerical simulation, the experimental and computational fluid dynamics was used to predict the entrainment under the inlet of vortex finder of the Shell type guide vane cyclone tube. The results showed that there was a short circuit flow in the Shell type cyclone tube, it occupied 39.3% of the total inlet flow rate. The force analysis of particles near the vortex finder inlet showed that the short circuit flow carded the particles with diameter smaller than 9 μm out of the separator. Tracking of the trace of particles escaping form the cyclone tube by numerical simulation, it was found that the particles with diameter greater than 9 μm were all trapped by Shell type cyclone tube, and the particles with diameter smaller than 9 μm escaped from separator tube through vortex finder inlet by short circuit flow or the dust exit by back-mixing. The former accounted for the main part of escape particles. The smaller the particle size was, the more particles escaped through vortex finder inlet.