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| DOI：10.13522/j.cnki.ggps.2020021 |
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| Experimental Study on the Hydraulic Performance of a Multi-stage Composite Mesh Filter |
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LI Shengbao, YUAN Zhihua, DU Siqi, LI Hui, HAN Qibiao, MENG Weixiao
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1. Farmland Irrigation Research Institute, Chinese Academy of Agricultural Sciences/Key Laboratory of Water Saving Agriculture of Henan Province/Key Laboratory of Water Saving Irrigation Project of Ministry of Agriculture, Xinxiang 453002, China;2. Mechanical and Electrical Engineering, Henan Agricultural University, Zhengzhou 450002, China;3. Jinfeng (China) Machinery Industry, Ningbo 315221, China
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| Abstract: |
| 【Objective】The multi-stage composite mesh filter is a new micro-irrigation filter we developed recently by integrating the meshes of 50, 80 and 120 in the same casting aimed to increase the filtering efficacy. The purpose of this paper is to present the results of an experimental study on its hydraulic performance.【Method】The experiment consisted of two parts. The first one used clean water in which we measured the water pressure drop across the filter. The second one was used muddy water to elucidate the combined impact of water flow rate and sediment content on hydraulic performance of the filter. We compared three flow rates: 18, 22 and 26 m3/h, combined with three sediment contents: 0.07, 0.10 and 0.13 g/L. In each treatment, we measured water pressure loss, change in flow rate, as well as turbidity of the water at the exit of the filter.【Result】Pressure drop of the clean water across the filter increased with water flow rate in a power-law with a R2 of 0.999 9. In the muddy water test, the flow rate was initially stable with the inflection point appearing about 18min-30min after inception of the experiment, after which it dropped sharply. Associated with such a flow rate change, the pressure loss across the filter was also stable at beginning, followed by a steady increase after the inflection point. It was found that the higher the flow rate and/or the sediment content was, the earlier the inflection point appeared for both flow rate and pressure loss, and that the clogging time was positively correlated to the duration of the filtration cycle. However, after the clogging, the turbidity of the effluent decreased, indicating an improved filtration effect.【Conclusion】The new multi-stage composite mesh filter we developed has a similar hydraulic performance as the single mesh filter, and it prolonged the filtration cycle thereby improving the filtration efficacy. It thus suits micro-irrigation systems. |
| Key words: micro irrigation; mesh filter; filtering efficacy; clean water test; muddy water test |
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