Influences Of Sediment Characteristics And Water Temperature Of Muddy Water On Anti-Clogging Performance Of Labyrinth Channel Emitter

Physical clogging caused by solid particles are considered as the most commonplugging form of emitter, and also the direct reason that leads to emitter clogging. Underspecial emitter channel structure, sediment characteristics and water temperature is a majorfactor affecting the anti-clogging performance of emitters. The objective of this study wasto investigate the influence of small sediment particles containing in muddy water onanti-clogging performance of oblique dental labyrinth channel drip emitters. A total of8types of muddy water with different particle size distribution (all less than0.1mm) weretested by short-term clogging tests, and determine the sensitive ranges of particle diametersand sediment concentrations that cause different clogging levels. According to the relativedischarge of emitters and the deposition sites of sediment particles in the labyrinth channel,these8kinds of particle sizes were classified into3clogging levels: difficultly clogged(DC), easily clogged (EC), and very easily clogged. Afterward, the intermittent dripirrigation method were adopted to investigate the effects of sediment concentration,sediment particle size and water temperature on the genesis and processes of labyrinth-pathemitter clogging, and conducted to further prove the results obtained from the short-termclogging tests Finally. the clogging level of drip irrigation systems was evaluated on thebasis of relative average flow volume (qr) and irrigation uniformity coefficient (Cu) ofemitter flow. The results aim to help in improving drip irrigation methods using water withhigh sediment concentration. By the above mentioned analysis and studies, this paper getsthe main results as follows:First, fine particles caused labyrinth emitter clogging at similar locations as largeparticles, which generally occurs at the inlet and corners of the vortex and low velocity of the flow channel. The sediment particles in labyrinth emitter had random characteristics forthe deposition cell and regularity for the sedimentation position.Second, the inlet pressure is a main factor affecting the clogging level, and the impactof the inlet pressure on clogging is neither monotonically increased nor decreased.Sediment concentration and particle sizes are also primary factors affecting emitterclogging. When the sediment particle sizes are less than0.1mm, the less the sedimentparticle size, the easier the emitter will be clogged. In addition, the degree of emitterclogging rises sharply with the increase of sediment concentrations. There is a couplingrelationship between the sediment characteristics and water temperature of muddy water. Ifparticle diameters ranges between0.03mm and0.1mm and the sediment concentrationless than1.25g/L do not significantly affect the clogging of emitters. When the sedimentparticle sizes less than0.031mm, the possibility of clogging rapidly increases at sedimentconcentrations of1.25-1.5g/L.Third, The degree of emitter clogging was also impacted by water temperature.Emitters were less likely clogged by muddy water with higher temperature. Theanti-clogging property of emitters improves with increasing water temperature. The reasonis that the possibility of collision, adhesion, cohesion and separation interaction among thesediment particles will be higher. The finer the sediment particle sizes, the more prominentare the influences of the water temperature on anti-clogging performance of emitters. Itwas found that in the summer when water temperature was relatively high labyrinth-pathemitters were prone to clogging by sediment with particle sizes less than0.031mm.Four and last, it is very difficult to evaluate the clogging level of the drip irrigationsystem by only using the relative emitter discharge. The article proposes a emittersclogging comprehensive evolution method and generalized model on the basis of relativeaverage flow volume (qr) and irrigation uniformity coefficient (Cu) of emitter flow.However, owing to the errors of the parametric hypothesis, the generalized model formulaexist big errors, the comprehensive evolution method of emitters clogging needs furtherstudy.