Transport Potentials Of Sediment And Anti-Clogging Properties Experimental Research In New-Type Drip Irrigation System With Return Flow Pipe

Traditional drip irrigation system has many defects In the process of operation,such as the emitter were clogged seriously in the end of the lateral and the sediment was mostly deposited in the end of lateral,otherwise,uniform coefficient was also bad while drip irrigation system has been running several cycles.In view of the above defects of traditional branch drip systems,the author puts forward a new-type drip irrigation system, which was alter from traditional irrigation system by added a return flow pipe. In the first place,studying the movement properties of sediment and the flow of the turbulent state in the drip irrigation system with different mainstream velocity by computer simulation to explore the theoretical basis of the new-type drip irrigation system with a return pipe. Meanwhile,according to the movement properties of sediment invented a anti-clogging emitter.Then,through the laboratory experiment and the outdoor medium experiment to explore the actual maneuverability of the new-type drip irrigation system. Finally, according to the study theory to develop a new-type drip irrigation system.1. The number of sand entering the emitter was decline gradually with the increase of velocity in lateral,and the turbulent flow region and the turbulent intensity present a decrease trend with the increase of mainstream velocity of lateral.When the velocity of mainstream in lateral was between 0.03~0.1m/s, the number of sand entering the new-type emitter was reduced by twenty percent or more, and the new-type emitter was altered from traditional emitter by adding a wedge baffle. Otherwise, the modification of the emitter in structure type had no obvious influence on the state of water in the lateral.2. The laboratory experiment showed that the number of sand which diameter was0~15um flow from the emitter in the new of new-type drip irrigation was less than traditional drip irrigation system. And the running time of the emitter was increase in turn with the increase of the rated flow, meanwhile, the running time of the new-type drip irrigation were longer than traditional drip irrigation system.3. The outdoor experiment showed that the sand concentration of water flow from emitter and the return pipe were greater with the increase of the velocity in the return pipe. The sand concentration in the water flow from the emitter were greater than traditional drip irrigation system. The sand deposited in the new-type irrigation system was more than traditional drip irrigation system.The outdoor experiment showed that d50 and d90 of sand diameter were greater with the increase of velocity of mainstream in the return pipe. The d50 and d90 of the sand which flow from the new-type irrigation system were bigger than traditional drip irrigation system.4. The uniformity coefficient of the new-type drip irrigation system was bigger than traditional drip irrigation system. Meanwhile, the uniformity coefficient were greater with the increase of velocity of return pipe.