玉米种子仿生脱粒机性能试验与参数优化

玉米种子仿生脱粒机是依据鸡喙离散玉米籽粒过程和裸手脱粒玉米籽粒过程的先离散后脱粒原理设计的,其具有低损伤、低破碎率等特点。为了优化玉米种子仿生脱粒机脱粒系统的有关参数,进而降低玉米种子在脱粒过程中的损伤,该文采用二次回归正交旋转组合设计的方法,以籽粒破碎率和脱净率为主要性能指标,选取差速辊转速、离散辊转速、脱粒辊转速和离散辊间隙、脱粒辊间隙为试验因素,对玉米种子仿生脱粒机进行了性能试验。并依据试验结果分别对离散辊转速与脱粒辊转速对破碎率和脱净率的影响,以及离散辊间隙与脱粒辊间隙对破碎率和脱净率的影响进行分析。分析结果表明:当离散辊转速在150~180 r/min和310~350 r/min,脱粒辊转速在270~350 r/min时,破碎率取得较小值;当离散辊转速在230~300 r/min,脱粒辊转速在150~200 r/min范围内时,籽粒脱净率取得最大值100%。当离散辊间隙在0~4 mm,脱粒辊间隙在5~9.2 mm时,籽粒破碎率取得最小值。当脱粒辊间隙在0~2.2 mm时脱净率取得最大值100%。综合以上结论,在试验拟合曲线的基础上按综合评价法进行优化,得到最优参数组合为差速辊转速90 r/min,离散辊转速350 r/min,脱粒辊转速为350 r/min,离散辊间隙4.6 mm,脱粒辊间隙4.6 mm。测得此时破碎率为0.226%,脱净率为99.317%,玉米芯完整度为100%,达到国家标准要求。

Performance test and parameter optimization of corn seed bionic thresher

Abstract: Corn seed bionic thresher was designed based on the principle of first discretizing and then threshing, which imitated the process of chicken beak discretizing corn grain and bare hand threshing, and had the advantages of low damage, low broken rate, and so on. In order to optimize the parameter of corn seed bionic threshing system, and then reduce the damage in the course of threshing of corn seed, this paper adopted the method of the quadratic regression orthogonal rotation combination design. Grain broken rate and removal rate were taken as the main performance indicators, differential roller speed, discrete roller speed, threshing roller speed, discrete roller gap, and threshing roller gap were selected as experimental factors, and the performance test of the corn seed bionic thresher was carried out. According to the test results, the influence of discrete roller speed and threshing roller speed on the broken rate and removal rate was respectively analyzed, as well as the influence of discrete roller gap and threshing roller gap on the broken rate and removal rate. Analysis results showed that when the threshing roller speed was fixed at a certain level, and the discrete roller speed increased from 150 to 350 r/min, the broken rate first increased and then decreased; when the discrete roller speed was fixed at a certain level, with the increasing of the threshing roller speed from 150 to 350 r/min, the broken rate decreased gradually; when the discrete roller speed was in 150-180 and 310-350 r/min, and the threshing roller speed was in 270-350 r/min, the broken rate was 0, which reached the lowest. The threshing roller speed was fixed at a certain level, and the discrete roller speed changed in the range of 150-350 r/min, the removal rate first increased and then decreased; when the discrete roller speed was fixed at a certain level, with the increase of threshing roller speed, the removal rate decreased gradually; when the discrete roller speed was in 230-330 r/min, and the threshing roller speed was in 150-300 r/min, the removal rate reached 100%, which was the highest. When the discrete roller gap was in 0-4 mm, and the threshing roller gap was in 5-9.2 mm, the broken rate was 0, reaching the lowest. When the discrete roll gap was fixed at a certain level, and the threshing roller gap reduced from 9.2 to 0 mm, the removal rate continued to increase; when the threshing roller gap was in 0-2.2 mm, the removal rate was 100%, which was the highest. On the basis of the experimental curve, through the optimization with the comprehensive evaluation method, the optimal combination of parameters was obtained: the differential roller speed of 90 r/min, the discrete roller speed of 350 r/min, the threshing roller speed of 350 r/min, the discrete roller gap of 4.6 mm, and the threshing roller gap of 4.6 mm. The verification test was carried out on the basis of these optimal conditions. It was found that the breaking rate was 0.226%, the net removal rate was 99.317%, and the corncob integrity was 100%. All the results meet the requirements of the national standard.