超细分级机进料管内颗粒分散的数值模拟

Numerical Simulation of Particle Dispersion in Feeding Pipe of a Superfine Classifier

采用欧拉-拉格朗日模型对超细分级机进料管内的气固两相流进行了数值模拟。通过引入颗粒浓度分布不均匀度,建立了颗粒分散性的评价方法,对比分析了导流片数量、尺寸、间距分布形式、入口风速、入口固体浓度、粒径对颗粒分散性的影响。结果表明:导流片的添加能提高颗粒的分散性;随着入口风速的提高,颗粒分散性逐渐提高,当风速大于13.6m/s时,分散性变化不大;随着入口固体浓度的增加,颗粒分散性降低;随着粒径的增加,颗粒浓度分布不均匀度增加,颗粒的分散性变差,当粒径大于50μm时,颗粒分散性基本不变。

The feeding pipe in the superfine classifier is a key factor affecting the particle dispersion performance.Euler-Lagrange model was used to simulate the gas-solid two-phase flow field in the feeding pipe.An evaluation method of particle dispersion was established by introducing the non-uniformity of particle concentration distribution.The effects of the number,size and spacing assignment of the guide vanes,the gas inlet velocity,the inlet solid concentration,and particle diameter on the particle dispersion were comparatively analyzed.The numerical results show that the guide vanes can improve the particle dispersion.The particle dispersion increases with the increase of the inlet velocity,and it changes smaller with the inlet velocity above 13.6 m/s.With the increase of the particle size and the inlet solid concentration,the non-uniformity of particle concentration distribution increases,and the particle dispersion becomes worse.When the particle size is bigger than 50 μm,the particle dispersion is basically unchanged.