水保所知识产出(1956---)知识库

为探明泥沙粒径与含沙量对内镶片式斜齿形迷宫流道滴头的堵塞过程和原因，采用筛分法，分选出6 个
小于0.1 mm 的粒径段，配制成不同含沙量的浑水，在恒压条件下，采用周期性间歇灌水试验观测流量变化，通过
电镜扫描法观测堵塞泥沙结构。试验结果表明：粒径为0.075≤D<0.1 mm 和0.03≤D<0.038 mm 的泥沙易引起滴
头堵塞；粒径为0.038≤D<0.05 和D<0.02 mm 的泥沙较难引起堵塞，且含沙量变化对堵塞的影响较小；粒径
0.02≤D<0.03 mm 和0.05≤D<0.075 mm 的堵塞情况介于上述两者之间。当含沙量为>1.2~1.3 g/L 时，是最易引起
堵塞的临界含沙量。当0.038≤D<0.1 mm 时，泥沙在流道内不易形成团聚体，造成滴头堵塞的原因是泥沙沉降、
堆积；当D<0.038 mm 时，泥沙易在流道中凝结成大的团聚体，是造成滴头堵塞的主要原因。

Drip irrigation technology is widely used due to its advantages including high efficiency water saving,
ability to adapt to the terrain and so on, but the problem of emitter clogging has been always a baffled to
researchers. Emitter clogging basically has three classes, respectively is physical clogging, chemical clogging and
biological clogging, of which the most common is physical clogging and it is represented by sediment clogging.
Studies show that even if the irrigation water after precipitation filtration, there is still have particle size of
sediment particles which are less than 0.1mm get into the emitters causing emitter clogging. However, previous
studies on this problem multi-use of computer simulation method to research the influence of emitter
anti-clogging by emitter structures, test verification is relatively rare and most studies only from a macro
perspective to observe emitters clogging, no in-depth study on the clogging mechanism. In addition, the previous
researches presents the sediment particle size range which are easily lead to cause emitters clogging need further
verification, sediment concentration corresponding in different size which are easily to cause emitters clogging
needs to be studied in-depth. So in order to investigate the influence of sediment particle size and sediment
concentration on the clogging processes of labyrinth channels emitters, periodic intermittent drip irrigation
experiments were carried out using muddy water containing particles with 6 different particle ranges (all less than
0.1 mm) which were screened by means of sieving method, each particle size range of sediment are formulated to
0.5,1.0,1.5 g/L of muddy water. Each irrigation time is 30min as same as the test interval, emitters flow collect
real-time and replace new pipes after the end of each group of treatment. In these experiments, the changes of
flow discharges were measured under a constant pressure and after the end of the trial clogging emitters are cut to
dried in the natural state, then collect the sediment which depositing in the labyrinth channel, at least the locations
of sediment clogging were observed using electron microscopy and take picture to compare the difference
between the status quo sediment and the clogging sediment to proven mechanisms that cause clogging of sediment
particle size in different range, it also provide a theoretical basis for how to select the appropriate filter. The
results show that, the sensitive sediment particle range that cause easy clogging is depending on the sediment
concentration. When the sediment concentration is less than 1.3 g/L, particle size is considered as the main cause
of clogging. The most easily cause clogging particle ranges are between 0.075-0.1 mm and 0.03-0.038 mm;
particle ranges from 0.05-0.075 mm and 0.02-0.03 mm are lesser; while the ranges that most difficult to cause
clogging are 0.038-0.05 mm and less than 0.02 mm. When the sediment concentration is greater than the critical
value that between 1.2-1.3 g/L, the effect of sediment particle size on clogging is weaker and sediment
concentration becomes the main factor to cause clogging. The results also appeal that sediments can easily
condense into aggregates to get drippers clogged when the sediment particle size range is less than 0.038 mm.