玉米收获机清选曲面筛设计与试验
|
摘要
为提高玉米收获机风筛式清选装置的清选效果,通过筛上颗粒受力分析,确定筛上颗粒运动状态与筛面方程f(x)存在函数关系。以编织筛为研究对象,利用CFD-DEM耦合技术,通过对比清选装置内平面、凸面、凹面3种编织筛的气流场及不同区域筛分特点,提出一种正弦曲线编织筛,并与去除尾筛的正弦曲线筛进行性能对比,确定保留尾筛筛分性能更好。以正弦曲线筛筛形系数、入口气流速度、气流方向角为试验因素,以籽粒清洁率和籽粒损失率为评价指标,设计二次正交旋转组合试验,建立了各因素与指标间回归数学模型,运用Design-Expert软件的多目标优化算法进行参数优化。获得参数最优组合为:筛形系数32. 35 mm,入口气流速度13. 73 m/s,气流方向角23. 86°。当玉米脱出物喂入量为5 kg/s,筛面振动频率为5. 15 Hz时,利用高速摄像及室内台架进行了正弦曲线筛工作机理试验和性能对比试验。试验结果表明,正弦曲线筛可实现对杂余的快速推移,并提高籽粒透筛概率。正弦曲线筛清选装置的籽粒清洁率为98. 07%,籽粒损失率为1. 16%,相较平面编织筛清洁率提高2. 45个百分点、损失率降低0. 79个百分点,满足国家筛分质量评价技术规范要求。
In order to improve the screening performance of the air-screen cleaning device of maize grain harvester,the relationship between the motion of grain on the screen and the function f( x) of screenshape was determined through the mechanics analysis of particle. In order to propose a type of sinusoidalshape screen,the woven screen was studied. Computational fluid dynamics and discrete element method( CFD-DEM) were coupled to compare and analyze the airflow in the cleaning device and the characteristics of flat,convex and concave screening. The screening performance of the sinusoidal-shape screen,compared with this one with tail screen was removed,was better. The quadratic orthogonal rotational-combinational simulation tests were designed. The coefficient of screen-shape and the inlet velocity of airflow and the direction angle of airflow were taken as factors,and the loss and cleanliness of maize grains collected were taken as indexes. The regression mathematical models between factors and indexes were multi-objective optimized by using Design-Expert software. The best combination of parameters was obtained,including the coefficient of screen-shape of 32. 35 mm,the inlet velocity of airflow of 13. 73 m/s,the direction angle of airflow of 23. 86°. The best combination of parameters was set in the bench test. The flat weave screen was compared with that of the screening performance of sinusoidal-shape screen. The experimental results showed that the sinusoidal-shape screen can realize the fast passage of maize debris,and increase the possibility of maize grains passing the screen when the total feeding quantity was 5 kg/s and the vibration frequency of the screen was 5. 15 Hz. The working mechanism and screening performance of the sinusoidal-shape screen were tested by high-speed camera and indoor bench. The experimental results showed that the state of movement of maize mixture on different screens was more favorable to the performance of the cleaning device. The cleaning rate of maize grains collected was 98. 07% and the rate of maize loss was 1. 16% after screening. Compared with the flat weave screen,the cleaning rate of maize grains was increased by 2. 45 percentage points and the rate of maize loss was reduced by 0. 79 percentage points, which met the requirements of technical specification for quality evaluation of screening in China.
In order to improve the screening performance of the air-screen cleaning device of maize grain harvester,the relationship between the motion of grain on the screen and the function f( x) of screenshape was determined through the mechanics analysis of particle. In order to propose a type of sinusoidalshape screen,the woven screen was studied. Computational fluid dynamics and discrete element method( CFD-DEM) were coupled to compare and analyze the airflow in the cleaning device and the characteristics of flat,convex and concave screening. The screening performance of the sinusoidal-shape screen,compared with this one with tail screen was removed,was better. The quadratic orthogonal rotational-combinational simulation tests were designed. The coefficient of screen-shape and the inlet velocity of airflow and the direction angle of airflow were taken as factors,and the loss and cleanliness of maize grains collected were taken as indexes. The regression mathematical models between factors and indexes were multi-objective optimized by using Design-Expert software. The best combination of parameters was obtained,including the coefficient of screen-shape of 32. 35 mm,the inlet velocity of airflow of 13. 73 m/s,the direction angle of airflow of 23. 86°. The best combination of parameters was set in the bench test. The flat weave screen was compared with that of the screening performance of sinusoidal-shape screen. The experimental results showed that the sinusoidal-shape screen can realize the fast passage of maize debris,and increase the possibility of maize grains passing the screen when the total feeding quantity was 5 kg/s and the vibration frequency of the screen was 5. 15 Hz. The working mechanism and screening performance of the sinusoidal-shape screen were tested by high-speed camera and indoor bench. The experimental results showed that the state of movement of maize mixture on different screens was more favorable to the performance of the cleaning device. The cleaning rate of maize grains collected was 98. 07% and the rate of maize loss was 1. 16% after screening. Compared with the flat weave screen,the cleaning rate of maize grains was increased by 2. 45 percentage points and the rate of maize loss was reduced by 0. 79 percentage points, which met the requirements of technical specification for quality evaluation of screening in China.
引文
[1]苏天生,韩增德,崔俊伟,等.谷物联合收割机清选装置研究现状及发展趋势[J].农机化研究,2016,38(2):6-11.SU Tiansheng,HAN Zengde,CUI Junwei,et al.Research status and development trend of cleaning unit of cereal combine harvesters[J].Journal of Agicultural Mechanization Research,2016,38(2):6-11.(in Chinese)
[2]郝俊发,韩增德,刘贵明,等.玉米脱粒机清选装置的研究现状及发展趋势[J].安徽农业科学,2016,44(5):322-324,330.HAO Junfa,HAN Zengde,LIU Guiming,et al.Research status and development trend of cleaning device of corn thresher[J].Journal of Anhui Agricultural Sciences,2016,44(5):322-324,330.(in Chinese)
[3]孙国建,李耀明,徐立章.风筛式清选装置中离心风机的研究现状及趋势[J].农机化研究,2014,36(1):242-246.SUN Guojian,LI Yaoming,XU Lizhang.Applications and researches of the centrifugal fan in the air-and-screen cleaning device[J].Journal of Agricultural Mechanization Research,2014,36(1):242-246.(in Chinese)
[4]李洪昌,李耀明,唐忠.风筛式清选装置清选性能试验研究[J].中国农机化,2010(6):54-57.LI Hongchang,LI Yaoming,TANG Zhong.Test study on cleaning performance of air-and-screen cleaning mechanism[J].Chinese Agricultural Mechanization,2010(6):54-57.(in Chinese)
[5]CLEARY P W,SINNOTT M D,MORRISON R D.Separation performance of double deck banana screens-part 2:quantitative predictions[J].Minerals Engineering,2009,22(14):1230-1244.
[6]FERNANDEZ J W,CLEARY P W,SINNOTT M D,et al.Using SPH one-way coupled to DEM to model wet industrial banana screens[J].Minerals Engineering,2011,24(8):741-753.
[7]杨忠高.弧形筛分级理论与参数研究[J].北京钢铁学院学报,1981(3):9-17.YANG Zhonggao.Research on classification theory and parameters of curved sieve[J].Journal of Beijing Iron and Steel University,1981(3):9-17.(in Chinese)
[8]张正,王清印,王印庚,等.弧形筛及生物净化池净化陆基工厂化海水养殖废水的效果[J].农业工程学报,2011,27(增刊2):176-181.ZHANG Zheng,WANG Qingyin,WANG Yingeng,et al.Effluent purification effect of system in sieve bend combined with four grade biological cleansing ponds in industrialized mariculture[J].Transactions of the CSAE,2011,27(Supp.2):176-181.(in Chinese)
[9]曹丽英,张跃鹏,张玉宝,等.筛片参数优化对饲料粉碎机筛分效率的影响[J].农业工程学报,2016,32(22):284-288.CAO Liying,ZHANG Yuepeng,ZHANG Yubao,et al.Influence of screen parameters optimization on screening efficiency of feed hammer mill[J].Transactions of the CSAE,2016,32(22):284-288.(in Chinese)
[10]李菊,王增彪,沈惠平,等.凸柱筛面并联振动筛的谷物筛分试验与分析[J].机械设计与研究,2016,32(1):150-154,158.LI Ju,WANG Zengbiao,SHEN Huiping,et al.Experiment and analysis of parallel vibrating sieve with convex column screen surface on grain screen[J].Machine Design and Research,2016,32(1):150-154,158.(in Chinese)
[11]邓嘉鸣,沈惠平,李菊,等.三维并联振动筛设计与实验[J/OL].农业机械学报,2013,44(11):342-346,328.DENG Jiaming,SHEN Huiping,LI Ju,et al.Design and experiment for three-dimensional parallel kinematics vibration sieve[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2013,44(11):342-346,328.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20131157&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2013.11.057.(in Chinese)
[12]张传根.玉米籽粒收获机清选筛体结构的优化研究[D].哈尔滨:东北农业大学,2016.ZHANG Chuangen.Structural optimization of the cleaning screen for maize grain harvester[D].Harbin:Northeast Agricultural University,2016.(in Chinese)
[13]WANG Lijun,DING Zhenjun,MENG Shuang,et al.Kinematics and dynamics of a particle on a non-simple harmonic vibrating screen[J].Particuology,2017,32:167-177.
[14]李洪昌,李耀明,唐忠,等.风筛式清选装置振动筛上物料运动CFD-DEM数值模拟[J/OL].农业机械学报,2012,43(2):79-84.LI Hongchang,LI Yaoming,TANG Zhong,et al.Numerical simulation of material motion on vibrating screen of air-andscreen cleaning device based on CFD-DEM[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2012,43(2):79-84.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20120217&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2012.02.017.(in Chinese)
[15]周文秀.玉米籽粒的物理力学特性研究[D].哈尔滨:东北农业大学,2015.ZHOU Wenxiu.The physical and mechanical properties research of corn grain[D].Harbin:Northeast Agricultural University,2015.(in Chinese)
[16]CO爦KUN M B,YALIN I,ZARSLAN C.Physical properties of sweet corn seed(Zea mays saccharata Sturt)[J].Journal of Food Engineering,2006,74(4):523-528.
[17]WANG Lijun,LI Rui,WU Baoxin,et al.Determination of the coefficient of rolling friction of an irregularly shaped maize particle group using physical experiment and simulations[J].Particuology,2018,38(6):185-195.
[18]WANG Lijun,ZHOU Wenxiu,DING Zhenjun,et al.Experimental determination of parameter effects on the coefficient of restitution of differently shaped maize in three-dimensions[J].Powder Technology,2015,284:187-194.
[19]王立军,张传根,丁振军.玉米收获机清选筛体结构优化[J/OL].农业机械学报,2016,47(9):108-114.WANG Lijun,ZHANG Chuangen,DING Zhenjun.Structure optimization of cleaning screen for maize harvester[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2016,47(9):108-114.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20160916&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2016.09.016.(in Chinese)
[20]杜小强,肖梦华,胡小钦,等.贯流式谷物清选装置气固两相流数值模拟与试验[J].农业工程学报,2014,30(3):27-34.DU Xiaoqiang,XIAO Menghua,HU Xiaoqin,et al.Numerical simulation and experiment of gas-solid two-phase flow in crossflow grain cleaning devic[J].Transactions of the CSAE,2014,30(3):27-34.(in Chinese)
[2]郝俊发,韩增德,刘贵明,等.玉米脱粒机清选装置的研究现状及发展趋势[J].安徽农业科学,2016,44(5):322-324,330.HAO Junfa,HAN Zengde,LIU Guiming,et al.Research status and development trend of cleaning device of corn thresher[J].Journal of Anhui Agricultural Sciences,2016,44(5):322-324,330.(in Chinese)
[3]孙国建,李耀明,徐立章.风筛式清选装置中离心风机的研究现状及趋势[J].农机化研究,2014,36(1):242-246.SUN Guojian,LI Yaoming,XU Lizhang.Applications and researches of the centrifugal fan in the air-and-screen cleaning device[J].Journal of Agricultural Mechanization Research,2014,36(1):242-246.(in Chinese)
[4]李洪昌,李耀明,唐忠.风筛式清选装置清选性能试验研究[J].中国农机化,2010(6):54-57.LI Hongchang,LI Yaoming,TANG Zhong.Test study on cleaning performance of air-and-screen cleaning mechanism[J].Chinese Agricultural Mechanization,2010(6):54-57.(in Chinese)
[5]CLEARY P W,SINNOTT M D,MORRISON R D.Separation performance of double deck banana screens-part 2:quantitative predictions[J].Minerals Engineering,2009,22(14):1230-1244.
[6]FERNANDEZ J W,CLEARY P W,SINNOTT M D,et al.Using SPH one-way coupled to DEM to model wet industrial banana screens[J].Minerals Engineering,2011,24(8):741-753.
[7]杨忠高.弧形筛分级理论与参数研究[J].北京钢铁学院学报,1981(3):9-17.YANG Zhonggao.Research on classification theory and parameters of curved sieve[J].Journal of Beijing Iron and Steel University,1981(3):9-17.(in Chinese)
[8]张正,王清印,王印庚,等.弧形筛及生物净化池净化陆基工厂化海水养殖废水的效果[J].农业工程学报,2011,27(增刊2):176-181.ZHANG Zheng,WANG Qingyin,WANG Yingeng,et al.Effluent purification effect of system in sieve bend combined with four grade biological cleansing ponds in industrialized mariculture[J].Transactions of the CSAE,2011,27(Supp.2):176-181.(in Chinese)
[9]曹丽英,张跃鹏,张玉宝,等.筛片参数优化对饲料粉碎机筛分效率的影响[J].农业工程学报,2016,32(22):284-288.CAO Liying,ZHANG Yuepeng,ZHANG Yubao,et al.Influence of screen parameters optimization on screening efficiency of feed hammer mill[J].Transactions of the CSAE,2016,32(22):284-288.(in Chinese)
[10]李菊,王增彪,沈惠平,等.凸柱筛面并联振动筛的谷物筛分试验与分析[J].机械设计与研究,2016,32(1):150-154,158.LI Ju,WANG Zengbiao,SHEN Huiping,et al.Experiment and analysis of parallel vibrating sieve with convex column screen surface on grain screen[J].Machine Design and Research,2016,32(1):150-154,158.(in Chinese)
[11]邓嘉鸣,沈惠平,李菊,等.三维并联振动筛设计与实验[J/OL].农业机械学报,2013,44(11):342-346,328.DENG Jiaming,SHEN Huiping,LI Ju,et al.Design and experiment for three-dimensional parallel kinematics vibration sieve[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2013,44(11):342-346,328.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20131157&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2013.11.057.(in Chinese)
[12]张传根.玉米籽粒收获机清选筛体结构的优化研究[D].哈尔滨:东北农业大学,2016.ZHANG Chuangen.Structural optimization of the cleaning screen for maize grain harvester[D].Harbin:Northeast Agricultural University,2016.(in Chinese)
[13]WANG Lijun,DING Zhenjun,MENG Shuang,et al.Kinematics and dynamics of a particle on a non-simple harmonic vibrating screen[J].Particuology,2017,32:167-177.
[14]李洪昌,李耀明,唐忠,等.风筛式清选装置振动筛上物料运动CFD-DEM数值模拟[J/OL].农业机械学报,2012,43(2):79-84.LI Hongchang,LI Yaoming,TANG Zhong,et al.Numerical simulation of material motion on vibrating screen of air-andscreen cleaning device based on CFD-DEM[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2012,43(2):79-84.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20120217&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2012.02.017.(in Chinese)
[15]周文秀.玉米籽粒的物理力学特性研究[D].哈尔滨:东北农业大学,2015.ZHOU Wenxiu.The physical and mechanical properties research of corn grain[D].Harbin:Northeast Agricultural University,2015.(in Chinese)
[16]CO爦KUN M B,YALIN I,ZARSLAN C.Physical properties of sweet corn seed(Zea mays saccharata Sturt)[J].Journal of Food Engineering,2006,74(4):523-528.
[17]WANG Lijun,LI Rui,WU Baoxin,et al.Determination of the coefficient of rolling friction of an irregularly shaped maize particle group using physical experiment and simulations[J].Particuology,2018,38(6):185-195.
[18]WANG Lijun,ZHOU Wenxiu,DING Zhenjun,et al.Experimental determination of parameter effects on the coefficient of restitution of differently shaped maize in three-dimensions[J].Powder Technology,2015,284:187-194.
[19]王立军,张传根,丁振军.玉米收获机清选筛体结构优化[J/OL].农业机械学报,2016,47(9):108-114.WANG Lijun,ZHANG Chuangen,DING Zhenjun.Structure optimization of cleaning screen for maize harvester[J/OL].Transactions of the Chinese Society for Agricultural Machinery,2016,47(9):108-114.http:∥www.j-csam.org/jcsam/ch/reader/view_abstract.aspx?flag=1&file_no=20160916&journal_id=jcsam.DOI:10.6041/j.issn.1000-1298.2016.09.016.(in Chinese)
[20]杜小强,肖梦华,胡小钦,等.贯流式谷物清选装置气固两相流数值模拟与试验[J].农业工程学报,2014,30(3):27-34.DU Xiaoqiang,XIAO Menghua,HU Xiaoqin,et al.Numerical simulation and experiment of gas-solid two-phase flow in crossflow grain cleaning devic[J].Transactions of the CSAE,2014,30(3):27-34.(in Chinese)