导叶式旋风管内短路流颗粒夹带的研究

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。

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

Based on the numerical simulation, the experimental and com-putational 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 carried 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.