The Design Of Drip-irrigation, Filter And Backwash Control System Based On PLC

The research focused on the first filtering device,the important equipment of filteringsystem of drip irrigation, considering the large sediment and serious contamination in waterby the trickle irrigation and the great waste of water resource by the agricultural floodirrigation in Xinjiang farmlands. This research designed an automatic backwash filterdevice(sand+net type) combining the actual production, use condition and the economicpurchasing power of the drop irrigation in Xinjiang cotton fields. The device can use generalrivers and meet the irrigation demands (flow velocity at80-150m3/h and irrigation load of800-1000mus).Technic of the traditional filtering equipment was improved in this study by rationalallocations and varietal combinations of filters for increasing filtering contents and achievingrealtime filtering and automatic backwash control online of control system based on the filtertechnique at home and broad. The research matched filters to achieve pressure and timecontrol and selected types of components, such as PLC(Programmable Logic Controller),thehardware of control system, pressure transducer, magnet valve and hydraulic drive valve andso on based on the analysis on the principle of automatic wash filters.The study simply designed the verification,debugging and run of the test by drawing theflowchart of reset,start,backwash under the pressure and time control and stop and compilingthe control ladder diagram of the control system after the analysis on the task flow of PLC.