Design And Test Of Spiral Air Spray Device In Vineyard

Vineyard spray is an effective method for the prevention and control of grape diseases and insect pests.With the development of the grape industry to a moderate scale,conventional air-assisted spray has insufficient shortcomings such as penetration of grape leaf curtains,uneven droplet distribution,and waste of liquid medicine.The spiral air feed spray device was designed,simulated and optimized for key structural parameters such as spiral structure parameters and their functions,outlet configuration and speed.Through the performance test,the spray effect was improved and enhanced,providing a new technology for high quality spray spraying in modern vineyards.According to the modern vineyard planting mode and sprayer plant protection operation requirements,the initial structure of the spiral air blower spray device is designed,and the three-dimensional assembly model of the air duct,spiral baffle,and wind box is established using SolidWorks software.The air outlet radius is 80 mm,the outer radius of the air duct is 100 mm,and the height is 70 mm.The fluid simulation analysis of the installation angle of the spiral baffle using Fluent software shows that when the installation angle of the spiral baffle is 30°,the wind speed distribution is reasonable and the spiral state is the best.For the optimization of the wind box parameters,we used the Design-expert software to design the L13(33)orthogonal test on the wind box air inlet wind speed,fillet radius and air inlet position.According to the test results,we selected the wind box parameter combination as wind speed 30 m/s and fillet radius.When it is 5 mm and the position of the air inlet is at the geometric center position,the minimum wind speed variation coefficient is 0.095403.The simulation test shows that the spiral air conveying device can enhance the gathering effect of the airflow and improve the uniformity of the wind speed at the air outlet.The simulation result and the measured value have a degree of fit of 0.9135,and the simulation model is correct.Based on the simulation model,the L13(33)orthogonal test scheme was designed for spray pressure,nozzle aperture,with or without spiral air delivery,and the linear regression equation of nozzle aperture,spray pressure and with or without spiral air delivery was determined.Through the interaction analysis of the orthogonal test results,it is concluded that the most significant factor affecting the uniformity of the droplets is the spiral wind tube.The nozzle aperture and spray pressure are the main factors affecting the droplet diffusion ratio,and the optimal combination of spray uniformity parameters is determined:with the aid of a spiral air cylinder,the nozzle diameter is 1.0 mm,and the spray pressure is 0.3 MPa,the droplet uniformity Diffusion ratio(DR)is 0.784,which is higher than the standard value of 0.65 for conventional air-blast spray.The indoor spray test results show that the spiral air duct helps the second impact atomization of the droplets and improves the uniformity of the droplets.According to the results of simulation calculations and indoor tests,the final structural parameters of the spiral air spray device were determined,and the prototype of the device was trial-produced for field testing.The results show that the droplet deposition density of the spiral air spray is increased by 8.47%and 24.03%respectively on the front and back sides of the blade compared with the conventional air-driven spray.The spiral wind increases the adhesion rate of the front and back of the grape leaves and the droplet deposition density,especially for the leaves.The backside adhesion and droplet deposition density have a significant impact.Under the condition of installing a spiral air duct,the difference in the adhesion rate between the front and back of the blade is less than 7%,and the adhesion rate on the back is more than 70%.The number of droplets per unit area on the front and back of the blade is greater than 70 particles/cm2,which meets the requirements of the "Air blower operation Quality" and "Pesticide Sprayer(Apparatus)Field Operation Regulations and Spraying Quality Assessment" operation requirements.