| 摘要: |
| 【目的】设计适合谷子清选的风筛式清选装置，为提高我国谷子的机械化收获水平提供支持。【方法】以编织筛和冲孔筛为研究对象，测定“龙谷31号”谷子脱出物的主要物料特性，采用Fluent仿真分析对上、下筛网分别为编织筛+编织筛、冲孔筛+冲孔筛、编织筛+冲孔筛的清选装置进行流场仿真模拟，利用自制谷子风筛式清选试验台测定上、下筛均为编织筛的振动筛面的风速，以籽粒含杂率和清选损失率为评价指标，对曲柄转速、风机转速、风机倾角进行三因素五水平正交试验并建立回归模型，再采用多目标变量优化方法，运用Design-Expert 8.0.6对回归模型进行优化求解，确定最优结构参数组合，然后以圆整后的最优曲柄转速、风机转速、风机倾角进行台架验证试验。【结果】Fluent仿真分析表明，当上、下筛网均为编织筛时，气流的透筛率较好，气流能够贯穿筛网且无涡流，后段气流被有效导出清选装置并维持较高流速。台架试验表明，筛面高度90 mm处风速低于60 mm处，有利于脱出物分散；筛面高度60 mm处风速高于30 mm处，对脱出物分离起催化作用；筛面风速最高为4.22 m/s，大于杂余悬浮速度，足够分离谷子籽粒中的轻杂余，上、下筛均为编织筛合理可靠。多因素正交试验表明，风筛式清选装置的最优作业参数为：曲柄转速239.8 r/min，风机转速920.23 r/min，风机倾角25.98°，理论籽粒含杂率为2.89%，清选损失率为1.78%。利用圆整值（曲柄转速240 r/min、风机转速920 r/min、风机倾角26°）进行台架验证试验，实际籽粒含杂率为2.95%，清选损失率为1.81%。【结论】台架验证试验的籽粒含杂率和清选损失率与理论优化结果的相对误差分别为2.08% 和1.69%，均小于5%，表明所设计的风筛式谷子清选装置结构可靠，满足谷子清选作业的工作需求。 |
| 关键词: 谷子 清选装置 风筛式清选 Fluent仿真 |
| DOI：10.13207/j.jnwafu.2026.03.018 |
| 分类号: |
| 基金项目:黑龙江省自然科学基金联合引导项目（LH2024E103） |
|
| Flow field simulation and performance test of millet air-screen cleaning device |
|
MAO Xin1, LI Shuaifei1, ZHANG Weiguo2, ZHANG Dongming1, ZHANG Ziheng1, WANG Zeming1
|
|
1.College of Engineering，Heilongjiang Bayi Agricultural University，Daqing,Heilongjiang 163319，China;2.College of Mechanical and Electronic Engineering,Northwest A&F University，Yangling，Shaanxi 712100，China
|
| Abstract: |
| 【Objective】The study aims to design an air-screen cleaning device for millet cleaning,enhancing the mechanization level of millet harvesting in China.【Method】Taking the woven sieve and perforated sieve as the research objects,the main material characteristics of threshed materials from‘Longgu 31’millet were determined.Fluent simulation analysis was used to simulate the flow field of the cleaning device with upper and lower sieves as woven sieve+woven sieve,perforated sieve+perforated sieve and woven sieve+perforated sieve,respectively.Wind speed on the vibrating screen surface with upper and lower sieves being woven sieves was measured using the self-made millet air-screen cleaning test bench.Taking the impurity rate of grains and the cleaning loss rate as the evaluation indices,a three-factor,five-level orthogonal test was conducted on the crank speed,fan speed and fan inclination angle,and a regression model was established.Subsequently,the multi-objective variable optimization method was utilized to optimize the regression model by Design-Expert 8.0.6,and the optimal structural parameter combination was determined.Finally,a bench verification test was carried out with the rounded optimal values of crank speed,fan speed and fan inclination angle.【Result】Fluent simulation analysis showed that when woven sieves were used for both upper and lower screens, airflow exhibited optimal penetration through the screens without vortex formation.The rear section airflow maintained high velocity while being efficiently exhausted from the cleaning device.Bench test revealed that wind speed at a sieve-surface height of 90 mm was lower than that at 60 mm,which was conducive to the dispersion of the threshed materials.The wind speed at a sieve surface height of 60 mm was higher than that of 30 mm,promoting the separation of the threshed materials.The maximum wind speed on the screen surface was 4.22 m/s,which exceeded the residue suspension speed,making it sufficient to separate the light impurities from the millet grains.This validates the reliability of using weaving sieves for both the upper and lower screens.The multi-factor test demonstrated that the optimal operating parameters for the air-screen cleaning device were as follows:crank speed of 239.8 r/min,fan speed of 920.23 r/min,fan inclination angle of 25.98°,theoretical grain impurity rate of 2.89%,and cleaning loss rate of 1.78%.A bench verification test was carried out using the round values (crank speed 240 r/min,fan speed 920 r/min,and fan inclination angle 26°).The actual grain impurity rate was found to be 2.95%,and the cleaning loss rate was 1.81%.【Conclusion】 The relative errors of grain impurity rate and cleaning loss rate between the bench verification test and the theoretical optimization results were 2.08% and 1.69%,respectively.Both errors were less than 5%,indicating that the designed air-sieve millet cleaning device had a reliable structure and met the operational requirements of millet cleaning operation. |
| Key words: millet cleaning device air-screen cleaning Fluent simulation |
