Simulation and test of corn seeds' dispersion and arraying transport in electromagnetic vibration hopper

Abstract: The electromagnetic vibration hopper can be used to disperse and transport corn seeds in order. However, presently, there are few studies on the mechanism of dispersion and arraying transport of corn seeds under circular electromagnetic vibration, and limited parameter optimization for electromagnetic vibration hopper, which result in unreliable effects and efficiency of stacked corn seeds' dispersion and arraying transport. In order to solve the problem, firstly, the theoretical study on the mechanism of stacked corn seeds' dispersion and arraying transport in electromagnetic vibration hopper was done, from which the regulations were summarized and the influential factors were concluded as inclination angle of bottom, orbit pitch and working voltage. Then a simulation model was established by EDEM (enhanced discrete element method), adopting 200 corn seeds and a hopper. Meanwhile 2 parameterized sinusoidal motion functions were respectively applied in vertical direction and circle direction for the hopper to enable its vibration effect consistent with the actual electromagnetic vibration hopper. In the simulation test, dispersion time and total time were test indices, while inclination angle of bottom, orbit pitch and working voltage were influence factors. By observing the motion state and motion trajectory of stacked corn seeds in the hopper and analyzing the relationship between influence factors and test indices, the theoretical study results were verified and supplemented. At the same time, the electromagnetic vibration hopper was optimized. Lastly, the orthogonal test was conducted based on actual corn seeds and electromagnetic vibration hopper to verify the rationality of simulation optimization results, and the total time was taken as test index, and the inclination angle of bottom, orbit pitch and working voltage as influence factors as previous simulation test. Consequently the following results were gained: 1) The dispersion motion of stacked corn seeds was a compound motion, including forward circular motion, centrifugal motion and sliding motion. In the heap of corn seeds, the higher position of one corn seed resulted in smaller movement speed; the larger radius resulted in faster movement. 2) When the hopper diameter and height were determined, there were 3 factors related to the motion state of stacked corn seeds' dispersion and arraying transport, namely inclination angle of bottom, orbit pitch and working voltage. Among them, the inclination angle of bottom mainly influenced the dispersion motion; the orbit pitch only affected the arraying transport motion; the working voltage had effect on both of the 2 motions. Specifically, with the inclination angle of bottom increasing, the efficiency of stacked corn seeds' dispersion was improved, whereas the total efficiency barely changed. If the orbit pitch was less than 35 mm, its increasing would improve the total efficiency, but further increasing would reduce the total efficiency. If the voltage was less than 220 V, its increasing would significantly enhance the total efficiency, but further increasing showed no benefit to the total efficiency, and on the other hand resulted in unstable motion state. 3) The optimized working voltage was 220 V, the inclination angle of bottom was 4°, and the orbit pitch was 35 mm. Under these conditions, the stacked corn seeds' dispersion and arraying transport were stable with a high total efficiency. Generally, this research enriches the mechanism of stacked corn seeds' dispersion and arraying transport under circular electromagnetic vibration, and also provides reference for directional packaging and directional sowing of corns.