Design and Test of a Crawler-Type On-Film Precision Cotton Seeding Device on DEM-CFD

To solve the limitation of speed in the operation of air-suction cotton precision seeding devices, a new crawler-type precision on-film seeding device was designed using an extended duckbill hole-forming device to produce hole-forming belts and lateral seed collection. Coupling simulation of seeding, and analysis of drag force and movement speed of cotton seeds were conducted on EDEM-CFD. A mechanical model of the operation was established, and the effects of the suction hole diameter, pressure relief block length, and wind pressure on seeding performance were analyzed. Regression models between influencing factors and seeding performance indices were established using response surface methodology. The test data were analyzed using Design Expert 10.0.3. The influence rules for each factor on seeding performance were established. The factors affecting the seeding qualified index exhibited the following order: air pressure > pressure relief block length > suction hole diameter. The optimization goals included defining the maximum value of a qualified single-seed index and the minimum value of the missing index, and the best parameter combination was obtained based on a suction hole diameter of 3.624 mm, pressure relief block length of 63.369 mm, and wind pressure of 3.797 kPa. According to the actual test conditions, the parameters were revised to include a suction hole diameter of 3.6 mm, a relief block length of 63.4 mm, and wind (air) pressure of 3.8 kPa for verification tests. The actual qualified single-seed index is 94.87% ± 0.98 %, the missing index is 1.45% ± 0.32%, and the multiple index is 3.68% ± 0.62%. The difference from the predicted value is within 5%, indicating that this study can provide a reference for the structural design and optimization of crawler-type on-film precision cotton seeding devices.