农田塑料暗管排水设滤冲淤技术

STUDIES ON TECHNIQUES OF DRAINING WATER AND WASHING SLUDGE FROM UNDERGROUND PLASTIC PIPE AND ITS FILTRATION CONTROL

塑料暗管在农田使用中易于淤塞失效。为了延长其使用寿命和提高经济效益,合理设滤与有效的冲淤是非常重要的。经研究,塑料暗管的淤积与土壤、管子、滤层等因素有关。其中主要是回填土不密实或土壤质地轻,稳定性差,土粒易随水渗流入管造成淤积。试验说明塑料暗管的孔宽<1.1mm亦能较好防淤;稻谷壳比稻草防淤效果高83.3％。因此,稻谷壳可作为水稻产区的主要滤料。我们将塑料暗管从灌渠旁引出地面,用泵引渠水冲淤,15分钟可冲出管中淤泥的一半(约4.8—11.3kg),相当于开塞自流放水冲淤效果的十倍。

The major problem in the application of underground plastic pipe on farm land is that the pipe would be filled up with sludge easily. Both siltation control and technique of washing sludge were good methods to prolong the service life of pipe and improve its efficiency. The data from our field experiments showed that the pipe siltation was related to certain factors such soil texture, pipe size and filtration layer. When backfill wasn't sufficiently close to the pipe wall, soll particle could flow into the pipe with rain or irrigation water. In addition, the lighter soil texture was, the more severe the pipe siltation would be. The pipe siltation also was related to the hole size of pipe, it was no problem if the hole size of pipe used was less than 1. 1mm.Being a filter material, rice chaff was much more effective than rice straw. Rice chaff could be used as main filter material in rice belt.The authors have initiateda technique of pumping water into the top of underground plastic pipe, which was led out over surface, to wash away sludge in the pipe. It only takes 15 minutes to wash away half amount of sludge in the pipe, this efficiency is 10 times higher than that of self-flow washing method.