涡流分级机流场特性分析及分级过程

AIR FLOW FIELD CHARACTERISTICS ANALYZING AND CLASSIFICATIONPROCESS OF THE TURBO CLASSIFIER

利用流体运动方程和平面强旋转流的流动特性分析了涡流分级机内空气流动特性和气固两相流运动特性。指出涡流分级机内主气流作二维运动 ,主气流速度场就时均值而言是一个点汇和一个Rankine涡的叠加 ,这将引起Tailer柱效应 ,形成均匀力场 ,有利于分级效率和精度提高。分析了涡流分级机的分级过程 ,并用“空气动力筛”概念说明分级原理。提出了改散物料分散性、改进流场均匀性的措施。

The characteristics of air flow and the air-solid two phase movement in a turbo classifier are analyzed by the dynamic equation of fluid motion combined with the features of intense circulating flow. It is pointed out that in the annular region the air motion in the turbo classifier is a plane motion and the superposition of a quasi free vortex and a point sink, in the sense of time average flow. This flow pattern may lead to the Tailer column effect and form a uniform force field in the turbo classifier, resulting in an improvement in the classifying efficiency and precision. The classification process of the turbo classifier is analyzed. The outer cylindrical periphery of the rotor cage is described as functioning an aerodynamic screen to clarify the operating principle of the vortex classifier. The measures to improve the dispersion of powder material and the uniformity of air flow field are put forward, which will be an instruction to understand and improve the function of the turbo classifier.