| 微灌砂石过滤器滤层泥沙的沉积与迁移特征 |
| |
| 引用本文： | 宋蕾, 蔡九茂, 翟国亮, 冯俊杰, 张文正. 微灌砂石过滤器滤层泥沙的沉积与迁移特征[J]. 农业工程学报, 2023, 39(4): 76-83. DOI: 10.11975/j.issn.1002-6819.202208021 |
| |
| 作者姓名： | 宋蕾 蔡九茂 翟国亮 冯俊杰 张文正 |
| |
| 作者单位： | 1.中国农业科学院农田灌溉研究所/河南省节水农业重点实验室，新乡 453002;2.中国农业科学院研究生院，北京 100081 |
| |
| 基金项目： | 河南省重大科技专项（221100110700）；中国农业科学院基本科研业务费院统筹项目（Y2022XC05）；新乡市重大科技专项（ZD2020009-03） |
| |
| 摘 要： | 为探明泥沙颗粒在砂石过滤器滤层中沉积与迁移的规律，选用3种粒径（>0.90～1.25、>1.25～1.60、>1.60～2.00 mm）的石英砂作为滤料，通过滤柱模型开展0.4‰的浑水过滤试验，分析滤层沉积与迁移的泥沙质量、泥沙粒度分布以及过滤时的水力性能。结果表明：过滤过程3种滤柱泥沙截留率分别为 97.08%、94.53%、90.50%，滤后水均满足微灌水质要求，但构成砂滤柱的滤料粒径越大，泥沙在滤层中分布越均匀。各砂滤层截留泥沙的粒径分布宽度自上向下分别为1.86、3.37、4.12、4.21，随滤层深度增加，截留泥沙颗粒粒径减小；在>0.90～2.00 mm 范围内，随滤料粒径增大，更多的细颗粒泥沙可以随水流排出过滤器，但中砂与粗砂全部截留在滤层中。综上，3种砂滤柱过滤效率的差异主要体现在小粒径泥沙截留量上，而在满足微灌水质标准的情况下，该部分小颗粒泥沙并不会使灌水器流道产生物理堵塞。同时，根据流速与压强分析得，大粒径的砂滤柱不仅流速稳定，压强升高较慢，而且纳污能力强。因此，在滤后水满足微灌水质的情况下，应当优先采用大粒径滤料，这样不仅可以提升过滤效率，而且节能省材。研究结果对砂石过滤器滤料粒径及滤层高度的优化具有重要意义。
|
| 关 键 词： | 泥沙 压强 流速 微灌 砂石过滤器 粒度分布 沉积 |
| 收稿时间： | 2022-08-21 |
| 修稿时间： | 2023-01-17 |
Sediment deposition and migration feature in the filter layer of micro-irrigation sand filter |
| |
| SONG Lei, CAI Jiumao, ZHAI Guoliang, FENG Junjie, ZHANG Wenzheng. Sediment deposition and migration feature in the filter layer of micro-irrigation sand filter[J]. Transactions of the Chinese Society of Agricultural Engineering (Transactions of the CSAE), 2023, 39(4): 76-83. DOI: 10.11975/j.issn.1002-6819.202208021 |
| |
| Authors: | SONG Lei CAI Jiumao ZHAI Guoliang FENG Junjie ZHANG Wenzheng |
| |
| Affiliation: | 1.Institute of Farmland Irrigation of CAAS, Chinese Academy of Agricultural Sciences/ Key Laboratory of Water-Saving Agriculture of Henan Province, Xinxiang 453002, China;2.Graduate School of Chinese Academy of Agricultural Sciences, Beijing 100081, China |
| |
| Abstract: | Abstract: The purpose of this study is to investigate the temporal and spatial migration of sediment in the sand filter column. Three kinds of sand filter columns (0.90-1.25, >1.25-1.60, and>1.60-2.0mm) were selected as the research object, and the sand filter layer was used as the fractal resistance model. The maximum pore diameters of the sand filter layers were 0.99, 1.14, and 1.41, and the average pore diameters were 0.41, 0.68, and 0.83. The Yellow River sediment of the People's Victory Canal was used as the raw water sediment impurity particles, where 0.4‰ muddy water was configured. The filtration rate was 2m3/h. After that, the filter column was removed to separate from the sediment during filtration. The quality of the sediment was calculated by the trapped filter layer of the three sand filter columns at different depths. The particle size distribution of sediment and sediment trapped by the filter column was measured by laser diffraction instrument. The results showed that the ratio of sediment intercepted by three filter columns was 97.08%, 94.53%, and 90.5%, respectively. The sediment intercepted by the surface filter layer accounted for 97.88%, 96.36%, and 81.48% of the total sediment intercepted by the filter column. Therefore, the smaller the particle size range of the filter column was, the larger the sediment retention ratio was, and the better the filtration effect was, but the more serious the surface filtration phenomenon was. An analysis was also made on the particle size distribution of the three filter layers at different depths. The D3 of the 0.90-1.25 sand filter column from the upper layer to the lower layer was 4.47, 1.00, 0.90, and 0.91μm. D98 was 476.30, 111.40, 98.31, and 97.79 μm. Span was 1.82, 5.13, 5.47, and 5.56; From the upper layer to the lower layer, D3 of ＞1.25-1.60 sand filter column was 3.77, 1.54, 0.97, and 0.99μm. D98 was 460.20, 344.20, 107.60, and 298.20μm. The Span was 1.95, 3.13, 4.50, and 4.47, and the D3 of ＞1.60-2.0 mm sand filter column from the upper layer to lower layer was 4.33, 3.50, 2.43, and 1.45 μm. D98 was 463.90, 456.00, 415.40, and 215.20 μm. The Span was 1.82, 1.86, 2.38, and 2.59. Consequently, the larger the filter column toward the lower layer was, the smaller the sediment particle size was, where the particle size tended to be concentrated. Each filter column was in the same depth of the filter layer, the larger the filter particle size was, the larger the particle size was, and the larger the particle size span was. Finally, the loss of sediment mass and particle size distribution were calculated using the sediment mass and particle size distribution intercepted by the sand filter column. Specifically, about 50% of the clay and silt particles of the original soil flew away in the process of the three sand filter columns, whereas, only 3% of the fine, medium and coarse sand of the original soil was lost. According to the hydraulic test, the smaller the particle size of the sand filter material composing the filter column was, the larger the reduction of the filter speed was, the larger the particle size of the filter material was, the gentler the flow rate was, the lighter the degree of blockage inside the filter column was, and the more stable the flow field of the water flow in the filter layer was. The larger the particle size of the sand filter layer was, the larger the pore diameter was, the slower the pressure rise was, and the stronger the anti-clogging ability of the filter layer was. This finding can provide a strong reference to optimize the layer thickness and particle size of the sand filter. |
| |
| Keywords: | sediments pressure flow velocity micro-irrigation sand filter particle size distribution deposition |
|
| 点击此处可从《农业工程学报》浏览原始摘要信息 |
|
点击此处可从《农业工程学报》下载全文 |
|
