关键词: 粉体技术, 卧轮式分级机, 进风方式, 入口气速, 分级性能

Abstract:

The traditional horizontal turbo air classifier normally has a tangential air inlet, which causes non-uniform flow flied distribution and low classification efficiency. Based on the previous research on the airflow path in the classifier, the traditional tangential air inlet was modified and two types of radial air inlet including a louvered one and porous one were designed in view of the whole flow field organization. Effects of the three air inlets on the classification performance were investigated experimentally. The result shows that the classifier equipped with the radial air inlets has the high coarse powder yield as well as the low fine particles mixing, indicating a deep separation degree of coarse and fine particles and high classification efficiency. The multi-layered structure of louvered air inlet helps to fully wash the coarse fraction, which reduces the probability of fine particles reporting to the coarse powder. Therefore, the classifier with louvered air inlet obtains the best classification performance, and its Newton classifying efficiency averagely increases 6% compared with the traditional classifier. Moreover, in case of the constant air volume, the inlet air velocity also affects the coarse powder yield, Newton classifying efficiency and classification accuracy index except for the cut size, and there exists a critical inlet air velocity for the better classification performance. The above results could provide new strategy to improve the performance of the turbo air classifier.

Key words: powder technology, horizontal turbo air classifier, air inlet type, inlet air velocity, classification performance