介电式种子分选机理及其设备的研究
摘要
介电分选原理是种子分选中的重要组成部分之一，它具有结构简单、适应性强、分
选效果好、可接种子活力进行分级的特点。目前，国内外对其研究及应用的热度越来越高。
但是，由于对该原理及其机具的研究起步较晚，许多方面的研究尚不够深入，使介电分选
机在生产上未能得到大面积的应用。为此，本文通过理论分析与试验相结合的工艺路线，
围绕着为介电分选机的设计开发提供依据这个中心，对介电分选机理及其设备进行了多方
面的研究。
通过将种子简化为一种复合介质模型，探讨了种子的电特性，分析了影响种子介电
特性的各因素以及种子的介电特性与种子活力之间的关系。通过对种子在电场中的极化情
况分析，推导出了种子在电场中所受到的极化力方程。在此基础上，建立了种子在双绕线
圈滚筒上的分选模型。为合理地确定介电分选机的结构参数和工况参数提供了理论依据。
在利用前人将双绕线圈简化成两根无限长平行导线的做法的基础上，将相邻以至远邻
电极的影响考虑在内，建立了双绕线圈所产生的电磁场模型。将此模型与前人建立的模型
进行了对比分析，并利用它对影响电磁场的各个因素进行了分析，得出了电磁场随各参数
变化的规律，并提出了改进分选效果、提高分选机性能的措施。结果表明：新建的模型克
服了前人所建立的模型的缺点，更符合于实际情况，它对分析各因素对电磁场的影响规律
以及在介电式种子分选机的参数设计时更具有指导意义。
通过对分选电极材料和型式的研究，首创了以铝作为芯材并具有双绝缘层的电极型式。
该电极的内绝缘层为聚乙烯，主要起绝缘作用；外绝缘层为聚氯乙烯，主要起保护聚乙烯
的作用，同时兼顾绝缘作用。通过对电极尺寸的研究，得出了内、外绝缘层的最小厚度。
在此基础上，设计了三种不同尺寸的电极，并利用由它们绕制的滚筒对谷子和小麦种子进
行了分选试验，得出了“无论是分选大粒种子还是分选小粒种子，都以小直径的电极缠绕
的滚筒为佳”的结论。为分选电极的正确选用提供了依据。
在将分选滚筒简化成具有电阻的电容器模型的基础上，通过理论分析分别得到了绝缘
层为单层介质和双层介质的电极所组成的滚筒的电容计算公式，并通过理论计算研究了影
响电容的各因素。同时，对分选滚筒所产生的电磁场的能量转换及滚筒消耗的功率进行了
理论分析。在此基础上，进行了试验验证，得出了分选滚筒的电容、能量、消耗的功率随
分选电压和生产率等参数变化的规律，为变压器的选型设计及分选机的功率匹配提供了依
据。
通过理论分析与试验相结合，确定了双绕线圈滚筒式介电分选机的总体结构及参数，
并利用试验研究确定了多滚筒介电分选机应配备的滚筒数量。在此基础上，根据带绒棉种
的特点，研制了介电式带绒棉种分选机。在国内首次解决了带绒棉种的分选难题，通过利
用带绒棉种在不同含绒率水平下进行的分选电压的单因素试验，得出了其分选规律。通过
对不同带绒棉种的分选试验以及在生产中的实际应用证明：介电式带绒棉种分选机的研制
是成功的，选后种子的各项指标都达到或超过了国家标准要求。
Dielectric separation is one of the important methods to separate
seed. The
dielectric separator has the characteristics of simple structure,
good adaptability,
reliable separating effect, and classifying seeds according to
the vigor differences that
other separation methods can not match. Although much attention
is being paid on
theory and application both in China and abroad, the dielectric
separator has not been
widely used in seed production. This is because the principle of
seed separation using
the dielectric property is new and the researches in many aspects
have not been done
thoroughly. Therefore, the purpose of this study is to provide
scientific basis for
dielectric separator design and development through theoretical
analysis and
experimental researches.
Based on modeling the seed as a compound substance, the
dielectric property of
the seed was studied. Meanwhile, the factors affected the
dielectric property of seed
and the relationship between the dielectric property and seed
vigor were both
analyzed. By analyzing seed polarization in the electric field,
the polarization force
formula of the seed was developed. The seed separation model on
the bifilar-winding-
cylinder was developed, which provided scientific basis for
determining both
structural and operational parameters for the dielectric
separator.
The previous model for electric field intensity of the
bifilar-winding-cylinder was
developed by means of simplifying the bifilar winding into two
parallel infinitely long
wires, and was widely applied. We developed a new electric field
intensity model with
the similar method, but taking into account the electric field
intensity produced by
both the neighboring electrodes and the other electrodes.
Comparative analysis
between the new model and the previous model was made. The new
model was used
to examine the factors affecting the electric field intensity and
the relationship
between electric field intensity and the parameters of the
bifilar winding was
established, and measures to improve separating effect and to
increase separator
performance were presented. Since the model eliminates the
weaknesses of the
* previous model, it is more practical, more accurate in analyzing
the effect of
parameters on the intensity of electric field and in designing
the seed separator.
Based on studies on electrode material and electrode
construction, a new
electrode was designed, with aluminum as conductor and two layers
of insulation.
Polyethylene is used as inner insulation material to provide
insulation and polyvinyl
chloride is used as the outer insulation material to protect
polyethylene and provide
insulation as well. The minimum thickness for both the inner and
outer insulation
layers was decided. Cylinders made from three electrodes of
different sizes were used
to test the separation effect on wheat and millet seeds. "Whether
small seeds or large
II
2
seeds, the cylinder with the smallest size electrode shows the
best separation effect",
which provides the scientific basis for accurate application of
the electrode.
On the basis of simpli1~ying the separating cylinder as a
capacitor model with
resistance, the capacitance formula for cylinders with
single-insulation-layer electrode
and two-insulation-layer electrode were established respectively.
Factors affecting the
capacitance were studied, energy of the electric field and power
consumption of the
cylinder were analyzed. Laboratory experiments were conducted to
test and verify the
theory. The capacitance, energy, power consumption of the
cylinder as a function of
separating voltage and productivity were determined, which
provided scientific basis
for the design of the transformer and power matching of seed
separator.
Based on the theoretical analysis and experimental studies,
structural and
operationa
选效果好、可接种子活力进行分级的特点。目前，国内外对其研究及应用的热度越来越高。
但是，由于对该原理及其机具的研究起步较晚，许多方面的研究尚不够深入，使介电分选
机在生产上未能得到大面积的应用。为此，本文通过理论分析与试验相结合的工艺路线，
围绕着为介电分选机的设计开发提供依据这个中心，对介电分选机理及其设备进行了多方
面的研究。
通过将种子简化为一种复合介质模型，探讨了种子的电特性，分析了影响种子介电
特性的各因素以及种子的介电特性与种子活力之间的关系。通过对种子在电场中的极化情
况分析，推导出了种子在电场中所受到的极化力方程。在此基础上，建立了种子在双绕线
圈滚筒上的分选模型。为合理地确定介电分选机的结构参数和工况参数提供了理论依据。
在利用前人将双绕线圈简化成两根无限长平行导线的做法的基础上，将相邻以至远邻
电极的影响考虑在内，建立了双绕线圈所产生的电磁场模型。将此模型与前人建立的模型
进行了对比分析，并利用它对影响电磁场的各个因素进行了分析，得出了电磁场随各参数
变化的规律，并提出了改进分选效果、提高分选机性能的措施。结果表明：新建的模型克
服了前人所建立的模型的缺点，更符合于实际情况，它对分析各因素对电磁场的影响规律
以及在介电式种子分选机的参数设计时更具有指导意义。
通过对分选电极材料和型式的研究，首创了以铝作为芯材并具有双绝缘层的电极型式。
该电极的内绝缘层为聚乙烯，主要起绝缘作用；外绝缘层为聚氯乙烯，主要起保护聚乙烯
的作用，同时兼顾绝缘作用。通过对电极尺寸的研究，得出了内、外绝缘层的最小厚度。
在此基础上，设计了三种不同尺寸的电极，并利用由它们绕制的滚筒对谷子和小麦种子进
行了分选试验，得出了“无论是分选大粒种子还是分选小粒种子，都以小直径的电极缠绕
的滚筒为佳”的结论。为分选电极的正确选用提供了依据。
在将分选滚筒简化成具有电阻的电容器模型的基础上，通过理论分析分别得到了绝缘
层为单层介质和双层介质的电极所组成的滚筒的电容计算公式，并通过理论计算研究了影
响电容的各因素。同时，对分选滚筒所产生的电磁场的能量转换及滚筒消耗的功率进行了
理论分析。在此基础上，进行了试验验证，得出了分选滚筒的电容、能量、消耗的功率随
分选电压和生产率等参数变化的规律，为变压器的选型设计及分选机的功率匹配提供了依
据。
通过理论分析与试验相结合，确定了双绕线圈滚筒式介电分选机的总体结构及参数，
并利用试验研究确定了多滚筒介电分选机应配备的滚筒数量。在此基础上，根据带绒棉种
的特点，研制了介电式带绒棉种分选机。在国内首次解决了带绒棉种的分选难题，通过利
用带绒棉种在不同含绒率水平下进行的分选电压的单因素试验，得出了其分选规律。通过
对不同带绒棉种的分选试验以及在生产中的实际应用证明：介电式带绒棉种分选机的研制
是成功的，选后种子的各项指标都达到或超过了国家标准要求。
Dielectric separation is one of the important methods to separate
seed. The
dielectric separator has the characteristics of simple structure,
good adaptability,
reliable separating effect, and classifying seeds according to
the vigor differences that
other separation methods can not match. Although much attention
is being paid on
theory and application both in China and abroad, the dielectric
separator has not been
widely used in seed production. This is because the principle of
seed separation using
the dielectric property is new and the researches in many aspects
have not been done
thoroughly. Therefore, the purpose of this study is to provide
scientific basis for
dielectric separator design and development through theoretical
analysis and
experimental researches.
Based on modeling the seed as a compound substance, the
dielectric property of
the seed was studied. Meanwhile, the factors affected the
dielectric property of seed
and the relationship between the dielectric property and seed
vigor were both
analyzed. By analyzing seed polarization in the electric field,
the polarization force
formula of the seed was developed. The seed separation model on
the bifilar-winding-
cylinder was developed, which provided scientific basis for
determining both
structural and operational parameters for the dielectric
separator.
The previous model for electric field intensity of the
bifilar-winding-cylinder was
developed by means of simplifying the bifilar winding into two
parallel infinitely long
wires, and was widely applied. We developed a new electric field
intensity model with
the similar method, but taking into account the electric field
intensity produced by
both the neighboring electrodes and the other electrodes.
Comparative analysis
between the new model and the previous model was made. The new
model was used
to examine the factors affecting the electric field intensity and
the relationship
between electric field intensity and the parameters of the
bifilar winding was
established, and measures to improve separating effect and to
increase separator
performance were presented. Since the model eliminates the
weaknesses of the
* previous model, it is more practical, more accurate in analyzing
the effect of
parameters on the intensity of electric field and in designing
the seed separator.
Based on studies on electrode material and electrode
construction, a new
electrode was designed, with aluminum as conductor and two layers
of insulation.
Polyethylene is used as inner insulation material to provide
insulation and polyvinyl
chloride is used as the outer insulation material to protect
polyethylene and provide
insulation as well. The minimum thickness for both the inner and
outer insulation
layers was decided. Cylinders made from three electrodes of
different sizes were used
to test the separation effect on wheat and millet seeds. "Whether
small seeds or large
II
2
seeds, the cylinder with the smallest size electrode shows the
best separation effect",
which provides the scientific basis for accurate application of
the electrode.
On the basis of simpli1~ying the separating cylinder as a
capacitor model with
resistance, the capacitance formula for cylinders with
single-insulation-layer electrode
and two-insulation-layer electrode were established respectively.
Factors affecting the
capacitance were studied, energy of the electric field and power
consumption of the
cylinder were analyzed. Laboratory experiments were conducted to
test and verify the
theory. The capacitance, energy, power consumption of the
cylinder as a function of
separating voltage and productivity were determined, which
provided scientific basis
for the design of the transformer and power matching of seed
separator.
Based on the theoretical analysis and experimental studies,
structural and
operationa
引文
1． 姜春云，创建种子工程推动农业上新台阶，全国种子工程学术研讨会论文集，1996． 10， P1～6。
2． 黄其振，我国种子产业的现状、前景与对策，全国种子工程学术研讨会论文集，1996． 10， P64～67。
3． 刘江，积极推进种子产业化开创种子工作新局面，全国种子工程学术研讨会论文集， 1996． 10，P7～13。
4． 汪裕安，略论我国种子发展的几项措施，全国种子加工学术讨论会论文，1985． 9。
5． 陈公望 甘帮兴，种子加工产业化工程的推进及其作用，全国种子工程学术研讨会， 1996． 10，P229～232。
6． 汪裕安，郭佩玉，搞好种子加工发展种子工程，全国种子工程学术研讨会论文集， 1996 10． P233～236．
7． 刘成果，实施“种子工程”推动农业上新台阶，全国种子工程学术研讨会，1996． 10。P14～ 17。
8． 别传爽，介电式种子分选机理的研究，北京农业工程大学硕士学位论文，1986年。
9． 别传爽 汪裕安，在种子加工流水作业中引进新技术，种子加工成套技术讨论会，1985 年9月
10． 张敏华，许乃章，项士英，种子介电分选的主要参数与工作机理的研究，农业机械学报， 1989年第3期，P44～50。
11． 米双山，齐新，潘存治，介电式种子分选机理的研究，《河北省科学院学报》，1994年第 11卷，第3期，P400～406。
12． 米双山，滕德福，棉花种子加工技术及加工工艺发展预测，96’全国种子工程技术与加工 设备学术研讨会论文集，1996年。
13． 齐新，米双山等，带绒棉籽介电分选机理的研究，《河北农业大学学报》， 1998年第21 卷，第1期，P60～64。
14． 常立志，任桂君，介电式农业种子清选机的试验与研究，种子工程与农业发展，中国农 业出版社，1997年，P8_43～847。
15． 李法德,李修渠，新型介电式种子精选机及其配套系统的研究与设计，农机化研究，1996， (1) P16～20
16． 种子物理特性和加工工艺综合研究鉴定材料汇编，北京农业工程大学，1988． 12。
17． 尤田束，一个改进的农产品介电特性的测试系统，农业工程学报，1998年， Vol．14。No．2，P217～219。
33． 赵玉巧等，新编种子知识大全，中国农业科技出版社，1998年10月
34． 孙一源，余登苑，农业生物力学及农业生物电磁学，中国农业出版社，1996年5月
35． 陈季丹，刘子玉，电介质物理学，机械工业出版社，1982年11月
2． 黄其振，我国种子产业的现状、前景与对策，全国种子工程学术研讨会论文集，1996． 10， P64～67。
3． 刘江，积极推进种子产业化开创种子工作新局面，全国种子工程学术研讨会论文集， 1996． 10，P7～13。
4． 汪裕安，略论我国种子发展的几项措施，全国种子加工学术讨论会论文，1985． 9。
5． 陈公望 甘帮兴，种子加工产业化工程的推进及其作用，全国种子工程学术研讨会， 1996． 10，P229～232。
6． 汪裕安，郭佩玉，搞好种子加工发展种子工程，全国种子工程学术研讨会论文集， 1996 10． P233～236．
7． 刘成果，实施“种子工程”推动农业上新台阶，全国种子工程学术研讨会，1996． 10。P14～ 17。
8． 别传爽，介电式种子分选机理的研究，北京农业工程大学硕士学位论文，1986年。
9． 别传爽 汪裕安，在种子加工流水作业中引进新技术，种子加工成套技术讨论会，1985 年9月
10． 张敏华，许乃章，项士英，种子介电分选的主要参数与工作机理的研究，农业机械学报， 1989年第3期，P44～50。
11． 米双山，齐新，潘存治，介电式种子分选机理的研究，《河北省科学院学报》，1994年第 11卷，第3期，P400～406。
12． 米双山，滕德福，棉花种子加工技术及加工工艺发展预测，96’全国种子工程技术与加工 设备学术研讨会论文集，1996年。
13． 齐新，米双山等，带绒棉籽介电分选机理的研究，《河北农业大学学报》， 1998年第21 卷，第1期，P60～64。
14． 常立志，任桂君，介电式农业种子清选机的试验与研究，种子工程与农业发展，中国农 业出版社，1997年，P8_43～847。
15． 李法德,李修渠，新型介电式种子精选机及其配套系统的研究与设计，农机化研究，1996， (1) P16～20
16． 种子物理特性和加工工艺综合研究鉴定材料汇编，北京农业工程大学，1988． 12。
17． 尤田束，一个改进的农产品介电特性的测试系统，农业工程学报，1998年， Vol．14。No．2，P217～219。
33． 赵玉巧等，新编种子知识大全，中国农业科技出版社，1998年10月
34． 孙一源，余登苑，农业生物力学及农业生物电磁学，中国农业出版社，1996年5月
35． 陈季丹，刘子玉，电介质物理学，机械工业出版社，1982年11月
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