Study On The Seed Suction Performance Of Sorghum Seedling Tray Seede

Artificial sowing of sorghum seedlings has high labor intensity,low efficiency,and high cost,which restricts the development of the sorghum industry.Realizing the mechanized production of the entire sorghum industry chain is the only way for the development of the sorghum industry.Due to the characteristics of small particle size,irregular shape,and light weight of sorghum seeds,existing hole tray seedling and sowing machines for vegetables,rice,and other crops cannot meet the requirements of precise sorghum planting.Therefore,the research and development of sorghum hole tray seedling and sowing machines,as well as the structural design of their key component,the sorghum special suction tray,is of great significance for improving the development of agricultural machinery equipment for sorghum production.This article combines the technical requirements of sorghum planting and adopts a combination of theoretical analysis,Fluent simulation,and experimental research to study the seed suction performance of sorghum hole tray seedling seeder.We tested the physical characteristics of sorghum seeds,designed the structure of an air suction sorghum seeder,analyzed the force process of sorghum suction,carrying,and metering,simulated the flow field distribution of the negative pressure chamber of the sorghum suction disc,and conducted a sorghum suction performance seeder bench test to verify the correctness of the suction process theory and simulation analysis.The main research content is as follows:(1)Taking the high-quality sorghum variety "Hongyingzi" for liquor use in Guizhou Province as the research object,the three axis dimensions of sorghum seeds were measured and analyzed.The average seed length was 4.07 mm,the average width was 3.54 mm,and the average thickness was 2.33 mm.The average thousand seed weight is 17.72 g,and the average density is 1192 kg/m ~3,The average moisture content is 9.53%.(2)Based on the mechanical and physical characteristics of sorghum seeds,the overall structure of the air suction hole tray seedling and sowing machine was designed,with a focus on key parameters such as the suction hole,diameter of the suction hole,and size of the suction plate;A force analysis was conducted on the process of sorghum seed suction,carrying,and metering,and the main factors affecting the seed suction performance were analyzed.Providing a theoretical basis for optimizing the negative pressure chamber structure and designing the pneumatic system.(3)Based on Ansys Fluent simulation analysis software,the flow field distribution state of the corresponding negative pressure chamber structural parameters was simulated.Through Fluent fluid simulation,the influence of negative pressure chamber thickness and outlet diameter on the flow field at the suction hole was analyzed,and the optimal negative pressure chamber thickness was determined to be 25 mm and the optimal outlet diameter to be 40 mm.Under the optimal negative pressure chamber structural parameters,the effects of suction hole diameter,suction hole type,and outlet negative pressure value on the flow field at the suction hole were studied.When the suction hole diameter was 2 mm,the turbulent kinetic energy at the suction hole was the smallest and the flow field distribution was the most uniform;When the suction hole type is a straight hole,the flow field distribution uniformity is optimal.A single factor simulation was conducted on the outlet pressure of the negative pressure chamber of the seed suction tray,and the results showed that the outlet negative pressure was 4 kPa,and the flow field distribution at the suction hole was relatively uniform.(4)A performance test bench for sorghum hole tray seedling and seeder was built,with qualification rate,replanting rate,and missed sowing rate as evaluation indicators.Single factor experiments were used to test the seed suction performance of the suction tray.When the suction height,negative pressure value of the negative pressure chamber,and suction hole diameter were 0～3mm,4 kPa,and 2 mm,respectively,the suction qualification rate was better.A three factor and three level regression orthogonal experiment was conducted using suction height,suction diameter,and suction negative pressure value as experimental factors.A mathematical regression model was established between the experimental indicators and experimental factors.It was found that when the suction negative pressure value,suction height,and suction hole diameter were 3.82 kPa,1.03 mm,and 1.98 mm,respectively,the theoretical suction disc suction qualification rate was 92.7%,and the re suction rate was 4.56%.Experimental verification was conducted under the optimal parameter combination of seed suction performance,and the results showed that the qualified rate of seed suction was 91.6%,the re suction rate was 4.32%,and the leakage rate was 4.08%.At the same time,the negative pressure value for stable seed carrying during the seed carrying stage was determined to be 2.5 kPa,and the positive pressure value for rapid seed feeding during the seed metering stage was determined to be 2 kPa,which can provide experimental basis for other types of seed metering devices.