Design and Experimental Analysis of A Stirring Device for A Pneumatic Precision Rice Seed Metering Device

To achieve a goal of precision seeding with 1 to 3 seeds per hill and to solve problems in a pneumatic rice seed metering device, including high resistance to seed sucking, poor stability of seed suction, and low seeding precision, a cylindrical seed stirring device was designed. The design was based on the characteristics of the rice seed flow in the seed suction area. A mechanical model of the rice seed in the seed stirring device was established. The relationships between the seed fluidity and the parameters of the seed stirring device were simulated with EDEM software. The effects of seed fluidity on the seed suction area were analyzed under different seed stirring device parameters. To analyze the influences of different parameters of the seed stirring device on seed stirring and to observe the relationships between different parameters and rice seeds, high-speed photography was used to observe the seed sucking and stirring processes. The super hybrid rice Y-2 You 900 was selected as the test material. The seeding precision was tested at different rotating speeds, negative pressures, and parameters of the seed stirring device. The test results showed that an increase in the diameter and thickness of the seed stirring device was beneficial for increasing the seed absorption rate and reducing the missed seed rate but also increased the rate of multiple-seed sucking and reduced the seeding precision. The optimal parameters of the seed stirring device were a cylinder thickness of 2 mm and a diameter of 5 mm. This study provides a certain reference basis for the seed suction process of a pneumatic seed metering device. © 2020 American Society of Agricultural and Biological Engineers. All rights reserved.