Research on a centrifugal high-speed precision seed metering device for maize with airflow-assisted seed filling and cleaning

Abstract

In this study, in order to solve the problem of low seeding performance of the centrifugal high-speed precision seed metering device for maize during high-speed seeding, a method of airflow-assisted seed filling and cleaning to improve seeding performance is proposed. A trapezoidal opening is designed at the bottom of the hole insert and an airflow outlet is designed on the front shell to perform airflow-assisted seed filling and cleaning processes. By combining the discrete element method and computational fluid dynamics method for simulation, the optimal trapezoidal opening length is 14 mm, and the optimal number of holes for airflow outlet 2 is 11 holes. When the seeding speed was 12 km/h, 15 km/h, and 18 km/h, the optimal inlet air pressure was 800 Pa, 800 Pa, and 900 Pa respectively. The results of the bench experiment show that when the seeding speed was 12 km/h, the omission, repeated, and pass indexes were 2.75 %, 5.12 %, and 92.13 % respectively. When the seeding speed was 15 km/h, the omission, repeated, and pass indexes were 2.02 %, 4.17 %, and 93.81 % respectively. When the seeding speed was 18 km/h, the omission, repeated, and pass indexes were 3.16 %, 3.98 %, and 92.86 % respectively. The power of the air-suction seed metering device was 471.65 W when the seeding speed was 12 km/h. The centrifugal high-speed precision seed metering device for maize with airflow-assisted seed filling and cleaning has only a power of 45.84 W when seeding at a speed of 18 km/h. It not only has a faster seeding speed, but also consumes only 9.8 % of the energy compared to traditional pneumatic seed metering device, which can reduce environmental pollution.