Study On Mechanism And Machines Of Cottonseed Dielectric Separation

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, which have attracted a lot of domestic and international scholars to carry on research and make a large number of valuable research results to this. However, research of separating cottonseed according to dielectric characteristic is less. Unfortunately, the dielectric separator has not been widely used in seed production 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.By analyzing the forces that cottonseed received on the bifilar-winding-cylinder, the myth model of dielectric separation was developed.By analyzing a 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 structure and operational parameters for the dielectric separator.By making comparative experiments among different electrode construction, the disciplinarian of electrode affecting electric field.Based on the theoretical analysis and experimental studies, structural and operational parameters for the dielectric separator were determined.The factors affecting the separating quality were analyzed, and the result show that separating voltage and the roller rotate speed are main factors affecting the separating quality except for system factors. Based on indoor germination experiment to cottonseed obtained under different combination conditions, and regression analysis the experiment data, the regression equation of taking sorting voltage and sorting cylinder speed as variable was obtained. The results of the experiment of vigor measurement of cottonseed, the experiment of indoor germination, the experiment of germination in farm and the experiment of parameters measurement of cotton seedling show the dielectric separator is successful. In addition, based on the theoretical analysis and experimental studies, the relationship between dielectric constant and cottonseed vigor was developed: seeds with the same breed and mass have high electric constant but low vigor. However the seed with low electric constant has high vigor. So, if excluded high electricity constant seeds, we can obtain high quality seeds. It offered the theory base, which use the dielectric separation can accomplish separation according to the seed vigor.