Authors

Abstract

To improve the operating effect of buckwheat classifying equipment and meanwhile reduce the dependence on tests in the process of operating parameter optimization of the equipment, this paper designed a three-level classifying screen for buckwheat, confirmed the structure and parameters of upper and lower sieves, established a three-level screening discrete element model for buckwheat with the EDEM software, and conducted the numerical simulation for the sieving processes at an amplitude of 24 mm, 28 mm and 32 mm, respectively. The results indicated that when the inclination angle of screen surface was 3°, the vibrational direction angle was 30° and the vibrational frequency was 4.5 HZ, as the amplitude increased, the conveying capacity of the classifying screen increased and at the same time the seed loss rate also increased, of which at 16 s, the loss rate was 0.03%, 0.37% and 1.42%, respectively; the proportion of medium particles in the collecting box of screen overflow was 2.88%, 8.65% and 17.65%, respectively; and the proportion of small particles in the collecting box of screen residue was 0.58%, 6.06% and 19.14%, respectively. Through comprehensive analysis of conveying capacity, screening loss and classifying effect, when the amplitude of the classifying screen was 28 mm, the classifying operating effect was good. This study can provide reference for the design and operating parameter optimization of buckwheat classifying equipment.

Abstract in Chinese

为改善荞麦分级设备作业效果、同时减少设备工作参数优化过程中对试验的依赖。设计了荞麦三级分级筛，确定了上、下筛片的结构及参数，应用EDEM软件建立了荞麦三级筛分离散元模型，并对振幅分别为24 mm、28 mm、32 mm时的筛分过程进行了数值模拟。结果表明：在筛面倾角为3°、振动方向角为30°、振动频率为4.5 HZ时，随着振幅的增大，分级筛输送能力增加，同时籽粒损失率也增大，16 s时损失率分别为0.03%、0.37%、1.42%，筛上物收集箱内中颗粒占比分别为2.88%、8.65%、17.65%，筛中物收集箱内小颗粒占比分别为0.58%、6.06%、19.14%。综合分析输送能力、筛分损失、分级效果，分级筛振幅为28 mm时分级作业效果较好。本研究可为荞麦分级设备的设计及工作参数优化提供参考。