Study on the Design and Performance of Seed Discharger for Peanut Plot Breeding Based on CFD-DEM Method

A seed discharger for peanut plot breeding was designed and its seed supply, seed carrying, seed discharge and seed clearing processes were analysed. Two single stroke cylinders were used for seed replacement and to avoid confusion between different varieties of seeds. The working performance of the seed discharger was simulated by CFD-DEM mothed. The simulation results showed that the seed section hole could adsorb the seeds stably, the adsorption force at the seed suction hole was about 0.02N, and the seed clearing time was 0.31s, when the rotation speed of the seed discharge cylinder was set to be 25r/min, the diameter of the seed suction hole was set to be 6mm, and the working negative pressure was set to be 5.5kPa. The developed seed discharger was installed on the test bench to carry out the central composite design experiment, and the test results were analysed and optimized by Design-Expert software. The optimal parameters of the seed discharger were obtained as follows: rotational speed of the seed cylinder is 24.38 r/min, the diameter of the seed suction hole is 5.73 mm, and the working negative pressure is -6.15 kPa. Finally, the seed discharger was tested in the field, and the result shown that the seed spacing pass rate was more than 90%, the multiple seeds rate was less than 6%, the seed missing rate was less than 4.5%, and the seed clearing rate was always 100%, which met the requirements of peanut plot seeding.