On-line Mixing Pesticide Technology And Device Based On Pipeline Spraying

Using pipeline spraying can greatly improve efficiency in mountainous orchard,but after spraying there were still remain pesticides in pipeline.Currently,people mainly clean pipeline by water to deal with residual pesticides,but this way is easy to cause pesticide waste and environmental pollution.Although on-line mixing pesticide technology can be used to reduce pesticide waste and environmental pollution,it is still vacancy in pipeline spraying.For this reason,this paper put forward to take on-line mixing pesticide technology in pipeline spraying and designed a device to achieve on-line mixing of pesticides and water at the outlet of pipeline.Using this device can safely,reliably and efficiently utilize pesticides and eliminate pesticides effects on environmental pollution.The main research includes:(1)The design of the mixer and parameter optimization:This paper designed basic structure of the mixer referred to mixing principle of jet-mixer and combined with actual situation of pipeline spraying.The analytic method based on CFD orthogonal test was adopted to research the influence on the mixer of pesticide absorbing and mixing performance by changing converging angle,diffusion angle,throaty diameter and throaty length 4 key structural parameters.Finally,this paper found the comprehensive optimal structure parameters which are converging angle is 22°,diffusion angle is 9°,throaty diameter is 2mm and throaty length is 6mm to realize optimization of structural parameters.(2)The hardware and software design of the on-line mixing pesticide device:According to hardware structural diagram of the on-line mixing pesticide device,this paper made the selection of water flow sensor,pesticide flow sensor,peristaltic pump and so on and also designed the hardware circuit.Based on this,finished the design of water and pesticide flow detection program,mixing ratio PID control program and human-computer interaction interface.The PID parameters are K_p=2.4,K_I=0.6 and K_D=0.2.(3)The mixing uniformity experiment:In order to evaluate the mixing effect by the uniformity of spatial distribution of on-line mixing pesticide device,this paper did the mixing uniformity experiment and used cofficient of spatial variation to evaluate it.In the mixing uniformity experiment,using using 20 meters high-pressure hose connected with spray gun to pipeline spraying,in the different condition of flow pressure of pipeline(2MPa,1.8MPa,1.6MPa)and mixing ratio(1:100,1:150,1:200)to measure mixing solution concentration variation in the spatial distribution and calculate cofficient of spatial variation.The experiment results shows that the maximum cofficient of spatial variation are 2.05%,which less than 5%,to meet the requirements of agricultural spraying.(4)The mixing stability experiment:In order to evaluate the mixing effect by the stability in time of on-line mixing pesticide device,this paper did the mixing stability experiment and used cofficient of time variation to evaluate it.In the mixing stability experiment,respectively using 20 meters,50 meters and 70 meters high-pressure hose connected with spray gun to pipeline spraying,with the same condition as the mixing uniformity experiment to measure mixing solution concentration variation in time and calculate cofficient of time variation.The experiment results shows that the maximum cofficient of time variation are 4.63%,which less than 5%,to meet the requirements of agricultural spraying.At the same time,it is also found that the minimum cofficient of time variation appears on using 20 meters high-pressure hose connected with spray gun to pipeline spraying.With the number of length increases of high-pressure hose,the cofficient of time variation has a tendency to increase gradually.Therefore,it is suggested that when utilizing on-line mixing pesticide device,using 20 meters high-pressure hose connected with spray gun to pipeline spraying to achieve better mixing effect with stability of time.The design of on-line mixing pesticide device based on pipeline spraying can realize on-line mixing work at the outlet of pipeline,which mixing uniformity and stability meet the requirements of agricultural spraying.This paper also can provide a reference for the application of on-line mixing pesticide technology in pipeline spraying.