关键词: 荞麦籽粒, 振动筛, 振动频率, 离散元, 数值模拟

Abstract: In view of the various problems in designing buckwheat vibratory screening equipment, including high dependence on tests in determining operation parameters, high cost for evaluating screening effects at different vibration frequencies, and long development cycle, a multisphere buckwheat grain model was established through manual filling based on EDEM according to the morphological characteristics of buckwheat grains. Additionally, according to the buckwheat grain screening requirements, the whole structure of the singledeck vibration screen and parameters of screen meshes were designed to establish a discrete element model. Meanwhile, numerical simulation of the screening process was separately carried out at 3.5 Hz, 4.5 Hz, and 5.5 Hz. The results showed that, in the same leaning angle of the screen, vibrating direction angle, and amplitude, the conveying capacity of the vibration screen was strengthened with the increase of vibration frequency. More grains that failed to pass the sieve were found in the oversize grain collecting box, where the proportion of grains was 0%, 0.86%, and 4.63% for 15 s, respectively. However, screening loss occurred at 5.5 Hz. Based on the above analysis, the vibration screen would achieve a better effect at 4.5 Hz. Therefore, this study could provide not only a model for discrete element simulation in designing buckwheat production and processing devices, but also a reference for optimizing the operation parameters of buckwheat vibratory screening equipment.

Key words: buckwheat grains, vibration screening, vibration frequency, discrete element, numerical simulation