Development of underground sprinkler irrigation device based on steel ball driving

Abstract: Sprinkler irrigation is a common method of supplying irrigation water and similar to natural rainfall. Sprinkler irrigation is used to assist the cultivation of agricultural crops, the maintenance of landscapes, and the revegetation of disturbed soils in dry areas during the period with inadequate rainfall. However, existing sprinkler irrigation devices can't be applied below the soil surface, and they must be equipped with protective devices buried in the soil. Therefore, crop pruning (especially high-frequency crop pruning), plowing and harvesting are significantly affected. In addition, little attention has been given to solve these problems. The objective of this study was to develop a good-performing sprinkler irrigation device situated below the soil surface. The existing sprinkling irrigation device, which consisted of an underground nozzle, a telescopic tube and a water tube, was improved. A thread was used to connect the telescopic tube and the underground nozzle. The water tube guided the water, and was part of the telescopic tube. The water tube could prevent dirt from entering the tube and ensure that the telescopic tube moved up and down smoothly. The telescopic tube was connected to the underground nozzle, and could supply water to the nozzle. The water tube was buried underground and connected with the water pipeline. The telescopic tube could move vertically along the water tube wall and extend to or retract from the ground. The top of the telescopic tube was connected to the underground nozzle. The underground nozzle device included sleeves, inner tube, hollow column, back plate, gear, rotary mechanism, connecting tube, joggle, filter element, elastic element and spray nozzle. The new sprinkling irrigation device was installed below the soil plow layer without a protection device. Therefore, the new sprinkler irrigation device had no effect on plowing. The function of drilling soil was connected with new sprinkling irrigation device, which could move from the soil plow layer to the height of irrigation. When the sprinkler irrigation device moved to the irrigation height, it could irrigate the soil. The rotation mechanism of new sprinkler irrigation device was equipped with a ball that hit and drove, which was a solution for clogged nozzles. After irrigation, the sprinklers could move back below the soil plow layer, allowing crop pruning and harvest. Compared with the existing mobile sprinkler irrigation system, the new device needed less work strength and had higher efficiency. The new device was in line with the national standards in GB/T22999, and suffered no damage under the maximum working pressure. The deviation of coverage diameter was within ±5% under 0.3 MPa. The variation of the sprinkler discharge rate was within ±5%. Rainfall distribution characteristics were in line with the national standards in GB/T19795.1. The new sprinklers underwent extensive quality testing in the laboratory. Moreover, device performance was also tested in the field to ensure uniform water distribution and higher efficiency.