Research on high-speed and clean production with a high-speed centrifugal maize precision seed metering device featuring variable hole insert numbers

Traditional pneumatic seed metering devices rely on air pressure for seed filling and carrying, resulting in high energy consumption and limited seeding speed. While centrifugal seed metering devices can achieve high-speed seeding, they have a narrow optimal seeding speed range, making low-speed seeding difficult. In this study, the number of hole inserts in a high-speed centrifugal precision seed metering device for maize was set to 2, 4, 6, and 8, enabling precision seeding at higher speeds and across a broader speed range. Different agitator wheel structures were designed based on the number of hole inserts. The motion characteristics of the gas and seeds were analyzed using a combination of Discrete Element Method and Computational Fluid Dynamics to determine the optimal agitator wheel structure. Bench test results indicated that the optimal seeding speed ranges for 2, 4, 6, and 8 hole inserts were 6-9 km/h, 12-18 km/h, 18-27 km/h, and 24-36 km/h, respectively. With 8 hole inserts, the maximum seeding speed reached 36 km/h, achieving a miss rate of 2.75 %, a repeat rate of 3.76 %, and a qualification rate of 93.49 %. The energy consumption of the high-speed centrifugal maize precision seed metering device during seeding was less than 411.71 kJ/ha, which is less than 9 % of the energy consumed per hectare by pneumatic seed metering devices. Additionally, the higher the seeding speed, the lower the energy consumption per hectare. At a seeding speed of 36 km/h, the energy consumption was 90.08 kJ/ha. Compared to pneumatic seed metering devices, the high-speed centrifugal maize precision seed metering device offers higher seeding speeds and lower energy consumption, enabling high-speed and clean production.