平面圆筛机的筛分过程研究和模型构建

Screen process of plane-surface round sifter and construction of the simulation model

针对圆筛机的筛分效率低的问题,对圆筛机筛分过程进行了研究。首先考虑单颗粒茶叶,研究了茶叶在筛面上的运动,求得了单颗粒茶叶的透筛概率;然后在单颗粒茶叶的基础上考虑茶叶层厚度的影响,在Matlab/Simulink中建立了圆筛机筛分流量模型。该模型能用于计算茶叶的输入/输出情况以及筛分效率。利用该流量模型对不同给料量和筛机转速下的筛分过程进行了仿真,得到了圆筛机的最佳转速和进料范围。研究结果表明,该模型能有效地模拟茶叶的筛分过程,为使筛分效率达到85%以上,筛机转速应控制在230 r/min^235 r/min的范围内,而筛机进料量应控制在300 kg/h^600 kg/h的范围内。

In order to solve the problems of low efficiency in tea plane-surface round sifter screening process , the motion path of the single- particle tea on the screen was analysed. By considering all positions where tea-leaves penetrate through the mesh, probability of tea-leaves going through the screen was obtained. Based on these and the influence of leaf layer＇s thickness, a sifter machine model was developed by solving the penetrating rate differential equation to simulate the screen process in assistance of Matlab/Simulink. The simulation result shows screen efficiency varies with running rate and feeding amount of the machine. To achieve high screen efficiency, screen rate should be kept in range of 230 r/min - 235 r/min and feed amount should be restricted between 300 kg/h and 600 kg/h.