关键词: 分离, 模型, 两相流, 转轮式分离器, 切割粒径

Abstract: It is important to establish the prediction model of the cut size with different structural and operational parameters for the design and operation of the turbo air classifiers. Based on similarity theory and analysis of the separation process, a new semi-theoretical model considering the effect of the classifier structure parameters was proposed. The model parameters were acquired according to experimental results. The model was validated by both the experimental work and the data reported in literatures. The model is applicable for the classifiers with different structures. The cut size increases first and then decreases with the increasing impeller rotating speed. The model in this paper can reproduce this non-monotonic relation, while the previous semi-theoretical model cannot. The results indicated that a larger inlet area and a smaller inlet angle is necessary to generate a strong swirl flow, which ensures that the cut size is sensitive to a low impeller rotating speed. When the inlet area is smaller or the inlet velocity is larger, the separation efficiency of the fine particles will be improved. The cut size will decrease with the increase of the particle feed rate. Adjusting the impeller rotating speed can change the cut size to meet different demands.

Key words: separation, model, two-phase flow, turbo air classifier, cut size