In order to further study the abrasion mechanism of sand and soil particles on the mulching parts of the full-film double-row mulching device during the mulching operation process, numerical simulation was carried out of the device mulching operation process using the discrete unit method. For the sandy soil particles, in order to approximate the irregular shape of the particles, the standard sphere type was selected to model the irregular shape of the filled sphere particles, and the basic structure of the sand particles included three types: spherical, elongated, and prismatic. Particle modeling was based on particles with a size of 1 mm, scaled up by a factor of 3, 1/2 for spherical, 1/3 for elongated, and 1/6 for prismatic [
20]. The simulation time step was 1. 405 × 10
−5 s, which is 40% of the Rayleigh time step, and the simulation was carried out for 2 s in total. For the scraper lift belt lifter with 12 scrapers per side, the distance between the two scrapers was set to 100 mm, and the motion was controlled using dynamic coupling through the coupling server panel in EDEM. Based on the optimized values of the operating parameters of the mulching device, the forward speed was 0.7 m·s
−1, and the scraper lift belt lifter linear velocity was set at 0. 67 m·s
−1 [
18]. The particle plant was a 135 mm × 100 mm rectangular plane, and the particle plant generated sandy soil particles at a rate of 3.5 kg·s
−1.
When
t = 0 s, the lift belt lifter scraper started moving at a 0.67 m·s
−1 [
18] linear velocity, and a steady inclined lift line speed was reached within (0~0.8) s (
Figure 5a); when
t = 0.8 s, the particle plant started to generate spherical, elongated, and prismatic sand particles with an initial velocity of −1 m·s
−1 in the
y-axis direction at a generation rate of 3 kg·s
−1, where the ratio of particles was 1/2 for spherical, 1/3 for elongated, and 1/6 for prismatic [
20]. The sand and soil particles reached a velocity of 1.14 m·s
−1 under their own gravity and the action of the lifting shovel, to enter the lift belt lifter and then contact the scraper and fill (
Figure 5b). When simulating a time range of 1.09–1.25 s, the power shaft rotation of the lifting belt lifter drove the scraper conveyor. This process allowed for the inclined lifting and conveying of the sand and soil particles, which can be seen in
Figure 5c. The sand and soil particles were lifted and conveyed at an inclined angle for further processing. The sand particles filled into the scraper conveyor and stable inclined lift between the two scrapers and the filled sand particles, due to the scraper extrusion and friction under the action of the formation of a closed right-angle triangle, and this meant that the sand and soil particles above the scraper conveyor had filled to a sufficient quantity and begun to gradually enter the soil conveying shell at a speed of 1.94 m·s
−1. The sand and soil particles were impacted at the bottom surface of the shell of the soil transport housing by the lifting action of the scraper at a maximum speed of 5.68 m·s
−1. With impact, friction, crushing, and scraping of sand particles on the bottom and left side surfaces of the soil transport casing due to their own inertia and surface irregularities, with the maximum abrasion damage of particles on the soil transport casing. After the sand particles had passed through the soil transport casing, the velocity of the particles decreased to 2.9 m·s
−1 under the reverse interception force of the casing and its own gravity. At this point, a small, discontinuous stream of sand particles occurred at the skid chute of the overburden device (
Figure 5d). When the simulation time reached 1.47~1.84 s, the uplifted sand particles passed through the soil cover of the mulching device, the velocity of the sand particles increased to 4.89 m·s
−1 under the interaction of the sand particles with the soil transport hood and the gravity of the sand particles themselves, and the movement of sand and soil particles into the chute drop zone had a greater impact on this area. At this point, the normal contact accumulation energy reached its peak, and the wear damage to the skidding trough was the most severe (
Figure 5e). After passing through the drop zone of the chute, the sand particles were intercepted by the 75° overburden side channel angle side plate, and then the particle velocity decreased to 1.05 m·s
−1. At this stage, the sand particles were scratched and worn by their own gravity and the sharp corners and edges of the sand particles on the chute, and the sand particles in the chute gradually formed a coherent flow of sand particles. The flow of sand particles gradually increased and tended to stabilize the overburden transport state (
Figure 5f). The amount of mulch on mulched seed beds is a key factor influencing the functional stability of a full-film duopoly production system; too much or too little mulch can have an effect on the effectiveness of the seed bed construction. When the amount of mulch is too large, the effective light area of the mulched seed bed is reduced, with serious constraints on the production function of “ground temperature enhancement and rainwater harvesting on the membrane surface”. When the amount of mulch is too small, the mulched seed beds are less likely to settle close to the surface, making it difficult to withstand the natural winds of the outside world and removing the film, which results in the failure of the “cover and vapor suppression” function of the seed bed [
30]. Therefore, in order to ensure the consistency and stability of the mulching of mulched seedbeds during the operation of the soil transfer-bed mulching device of the operating machine, calculations need to be made of the amount of overburden. Combining the construction characteristics of full-membrane double-row ridged seed beds in Gansu Province, the horizontal belt mulching type full-film double-monopoly furrow mulching machine main technical parameters could be determined, as shown in
Table 1: laminator operating speed 2.80–3.60 km·h
−1, membrane edge mulch width 90~110 mm, and mulch thickness of 20~30 mm, and the theoretical soil cover at the membrane side of the chute was calculated to be 3~4 kg·s
−1. When the simulation time reached 1.84 s, the mulching device tended to stabilize the mulch delivery state. To clarify the operational performance of the mulching device, a sensor was installed at the outlet of the mulching device chute, for detection of the amount of mulch after the action of the mulching device and calculation of mulch results from sensor data. The soil cover at the outlet of the skidding chute was 3.46 kg·s
−1. Therefore, from the comparison of the theoretical mulching amount and the mulching amount obtained from the sensor detection, it can be seen that the mulching device mulched the soil better.