Abstract：To allow an impact sprinkler to work in a low working pressure, an air admission structure can be installed coaxially in the water tube of sprinkler to form a water-air two-phase jet. The admitted air can make an impact sprinkler have a more uniform water distribution of irrigation. Further, the air admission pipe can convey liquid fertilizer or pesticide during irrigation, making the impact sprinkler multifunctional. In this paper, a series of experiments were carried out to investigate the capacity of an air admission structure for sucking both air and water into an impact sprinkler. The suction capacity is measured by water mass flow rate and vacuum degree. The structural parameters include inner diameter d, suction pipe engaging length L and nozzle convergent angle θ. All experimental work was conducted by employing 30PY impact sprinkler. When the nozzle convergent angle θ is increased from 30° to 65° under the same working pressure, the water flow rate reduced, and affected the two fluid mixing ratio in the sprinkler. The reference engaging length is zero, where the air admission pipe outlet jut meets the sprinkler nozzle outlet. When the suction pipe engaging length was varied in the range of -4 to 6 mm, the suction capability increased to the maximum from zero gradually and L=2 mm is recommend because the suction capability was close to the maximum at this length. The sucked water flow rate increased with increasing sprinkler working pressure and inner diameter. Results of this study have formed a base for air admission impact sprinkler application in engineering.
向清江, 许正典, 陈超. 30PY摇臂式喷头掺气与掺液的抽吸性能试验[J]. 排灌机械工程学报, 2018, 36(1): 82-87.
XIANG Qingjiang, XU Zhengdian, CHEN Chao. Experiments on air and water suction capability of 30PY impact sprinkler. Journal of Drainage and Irrigation Machinery Engin, 2018, 36(1): 82-87.
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