关键词: 颗粒物料, 分离, 粉碎, 粒度分布

Abstract: In the process of producing expanded corn flour,the vibrating screening machine is often used to sift the expanded cereal powder after crushing to obtain powder with the demand granularity,but the process is complicated. The air classifier was used to classify the crushed puffed black rice powder to remove coarse powder more than 20 meshes.The variation effect of separating coarse powder more than 20 mesh of puffed black rice powder is studied by changing the speed,secondary air flow and the concentration of air and solid of the classifier is investigated. And the optimum value of the changing parameters is obtained. During the experiment,it is found that when the classifier grade puffed black rice powder,it also shows the grading function. In the process of experiment,the classifier has the effect of pulverizing at the same time of puffed black rice flour. And the crushing mechanism of the classifier on material is discussed. The experimental results show that the change of the rotational speed,gas concentration and secondary air flow of the classifier will significantly affect grading the extruded black rice. When the rotational speed of the classifier is 90r/min,the secondary air volume is 175.60m³/h and the solid concentration is 0.12kg/kg,the classification effect is good. The two grinding action of dispersing cone and classifier wheel expanded black rice flour were verified. Based on the previous work,an industrial production line which uses a classifier and the former crushing equipment was proposed,thus providing an efficient and integrated method for controlling the particle size of puffed grains.

Key words: granular materials, separation, crushing, size distribution