Research On Key Technology Of Wheat Seed Metering System With Pneumatic Conveying

The traditional wheat seeder of our country is mainly based on the “one device and one line” type.There exist problems that the structure is complex and production cost is high.Moreover,there are problems such as high seed broken rate and poor consistency of each row when high-speed operations are performed.Due to its large working width,high work efficiency,low seed damage rate,good consistency of all rows of displacement and seed adaptability,"one device,multiple lines" type seeding method is adopted in the pneumatic transportation type wheat seeder.In the new device,high-speed air flow is adopted as a power carrier for seed input.Moreover,this device can reduce the number of metering and production costs.The seeding system test stand is one of the important means used in the research and development of the pneumatic conveying seeder.It can not be limited by location,environment,and season.It improves the repeatability and economy of the test and shortens the research and development cycle.Based on the existing researches at home and abroad,this paper studied the key technologies of the pneumatic conveying wheat seeding system,completed the construction of the test bed for the pneumatic conveying wheat seeding system,and conducted relevant performance tests to obtain the excellent scheduling performance operating parameters.The specific research content is as follows:(1)By studying relevant research data of pneumatic conveying seeders at home and abroad,the research status and working principle of pneumatic conveying seeders are clearly defined.Based on the agronomic requirements for wheat cultivation,the overall structure of the pneumatic conveying wheat seeding system is determined.Quantitative seeding devices,conveying devices,air distribution devices,wind sources and other key parts of the main operating parameters are also determined.The key components of the device were newly designed based on the simulation results.(2)Through establishing the pneumatic conveying wheat seeding system,the relevant indexes of the pneumatic conveying wheat seedling under different conditions are measured: the coefficient of the total displacement stability was in the range of 0.59%<1.3%,and each row of displacement is measured.The consistency coefficient of was in the range of 3.06% <3.9%,and the seed fragmentation rate was in the range of 0.169%<0.5%.All the indicators met the national standards and industry standards.(3)Through the regression analysis of the test data,the mathematical model of the coefficient of variation and the influencing factors of the consistency of each row were obtained.The significance test of each factor was performed by the regression equation and the response surface curve of the coefficient of each influence factor for each row was obtained.The mutual influence rules and reasons of each factor were analyzed.(4)According to the optimization analysis of test data,the optimal combination of the parameters of the pneumatic conveying wheat seeding system test bed were obtained.The value of wind pressure is 2.9k Pa.The value of sheave speed is 40r/min.The value of cone angle is 89.6o.The coefficient of variation of sexuality is 1.686%.In this paper,the results will provide reference and reference for the further study of pneumatic conveying wheat seedling system;it will practically influence the development and popularization of pneumatic conveying wheat seeder;it will improve the efficiency of wheat seeder operation,increase crop yield,and improve the economic benefits and the promotion of the sowing mechanization development play an important role.