Research On Key Components Selecting Machine Of Soybean Seeds Based On EDEM

Soybean has been cultivated in China for a long history and is a major source of oil and a major source of vegetarian protein.In order to improve the survival rate and yield of soybean,it is necessary to conduct dust removal and sorting before planting to obtain high purity seeds.At present,the dust removal and sorting of soybean seeds are still carried out by traditional artificial methods,which greatly restricts the development of soybean industry.Therefore,it is of great importance to develop select machines with strong adaptability,high clutter rate and low loss rate suitable for agricultural modernization and increasing famers’ income.This thesis takes soybean seed sorting machine as the research object,the research content is as follows :(1)Taking soybean seed as the research object,the material characteristics of soybean contaminated by dust and insect-infested beans in soybean mixture were studied,and the idea of classification and sorting was put forward;the dust removal system includes the design of blowing fan and dust removal box;the separation system includes the calculation of the friction separation belt and the upper roller from the inlet hopper outlet and the selection of the friction separation belt.Based on CATIA software,the overall model of the selection machine was constructed.(2)The dust removal system was simulated by using CFD-EDEM two-phase flow coupling,and the dust removal rate and soybean loss rate were used as performance indexes.According to the maximum influence interval of the previous single-factor analysis,the three factors of wind speed,wind inclination angle and tuyere opening were selected and Box-Behnken design principle was adopted,the regression fitting analysis was carried out by Design-Expert10 software.The optimal parameter combination was obtained as follows: the wind speed was 5.3m/s,the wind inclination angle was 23.4°,and the tuyere opening was 45.6mm.At this time the model predicted that the dust removal rate was 100% and the soybean loss rate was 0%.(3)The contact coefficients of high-quality bean and insect-infested bean,insect-infested bean and insect-infested bean were calibrated by cylinder lifting method,and the accumulation angle was used as the indicator.Three factors of collision recovery coefficient,static friction coefficient and rolling friction coefficient were selected by central combination experiment design,and the regression fitting analysis was carried out.The optimal parameter combination was as follows: the collision recovery coefficient of insect-infested bean and insect-infested bean was 0.29,the static friction coefficient was0.70 and the rolling friction coefficient was 0.21.The collision recovery coefficient of high-quality bean and insect-infested bean was 0.36,the static friction coefficient was 0.60 and the rolling friction coefficient was 0.25.The contact coefficients of high-quality bean and cotton canvas tape,insect-infested bean and cotton canvas tape were calibrated by the inclined plane method,and the rolling friction angle was used as the indicator.Three factors of collision recovery coefficient,static friction coefficient and rolling friction coefficient were selected by central combination experiment design,and the regression fitting analysis was carried out.The optimal parameter combination was as follows: the collision recovery coefficient of high-quality bean and cotton canvas tape was 0.2,the static friction coefficient was 0.43 and the rolling friction coefficient the 0.065.The collision recovery coefficient of insect-infested bean and cotton canvas tape was 0.15,the static friction coefficient was 0.62 and the rolling friction coefficient the 0.18.(4)Discrete element EDEM software was used to simulate and analyze the belt sorting device with the upper and lower separation rate as the performance indicator.According to the maximum influence interval of the previous single-factor analysis,the three factors of belt speed,longitudinal dip angle and outlet height were selected and Box-Behnken design principle was adopted for regression fitting analysis.The optimal parameter combination was obtained as follows: the belt speed is 0.44m/s,the longitudinal dip angle is 9.6°and the outlet height is 100 mm.At this time the model predicts that the maximum lower separation rate is 87.24% and the maximum upper separation rate is 96.5%.