Authors

Abstract

To investigate the influence of airflow distribution stability above the screen surface on the cleaning performance of an air-sieve millet cleaning device, this study employed the lattice Boltzmann method (LBM) to construct simulation models of screen surface flow fields with different screen types. The effects of airflow angle and airflow velocity on the distribution characteristics of airflow near and above the screen apertures were analyzed. The results showed that the flat square-hole screen exhibited high flow-field stability under various airflow conditions, whereas the perforated and fisheye screens were more susceptible to turbulent interference and had poorer uniformity. A simulation validation experiment was carried out using a self-developed airflow velocity and volume monitoring system, and the simulated and measured results showed high consistency in both variation trends and magnitudes, confirming the model’s accuracy. Further bench-scale comparison tests indicated that the flat square-hole screen achieved the best cleaning performance, particularly when using the screen aperture combination of 10 mm (upper screen) and 8 mm (lower screen), resulting in the lowest loss rate and impurity rate. The findings of this study provide a theoretical basis and experimental reference for optimizing screen surface structures and improving the cleaning quality of millet cleaning devices.

Abstract in Chinese

为揭示风筛式谷子清选装置筛面气流分布稳定性对清选性能的影响规律，本研究采用格子玻尔兹曼方法（LBM）构建了不同筛型的筛面流场仿真模型，分析了气流角度与气流速度对筛孔附近及筛孔上方气流分布特性的作用机制。结果表明，平纹方孔筛在不同气流条件下均表现出较高的流场稳定性，而冲孔筛和鱼眼筛的流场分布易受湍流干扰且均匀性较差。基于自主设计的风速风量监测系统开展了仿真验证试验，仿真与实测结果在变化趋势及数量级上高度一致，验证了模型的准确性。进一步的台架对比试验表明，平纹方孔筛清选性能最优，尤其在上筛10 mm、下筛8 mm的筛孔组合下，损失率最低且含杂率最小。本研究结果为优化谷子清选装置筛面结构、提升清选作业质量提供了理论依据和试验参考。