Orchard Air Assisted Electrostatic Spray And Spray Characteristics Research

In recent years, the apple industry has become one of the most important channels for the farmers, and the planting area is increasing.So far,the apple orchards of our country are small, household management, aging, spacing of apple trees is small, resulting in the difficulties to plant for the orchard mechanization, and the low mechanization level. The development of modern new orchard cultivation mode, provides conditions for the realization of orchard mechanization. As one of the orchard management measures, spraying technology not only relates to the effectiveness of pest control and timeliness, but also directly affects the yield of fruit tress, the quality of fruits, and the efficiency of working and so on,however, the air assisted electrostatic spray technology is a combination of air assisted hydraulic spray and electrostatic spraying technology, it has the effects of two times of atomization, reducing the rate of spray drift, increasing the droplet deposition in a target, especially in the blade back and inside the crown, improved the rate of drug utilization and production efficiency, improved the pest control effect, and reduced the environmental pollution caused by pesticide and labor costs, so the spray technology research has become the focus of current spraying technology research. But the current studies mostly concentrated on the theory of electrostatic spraying, electrostatic spraying is mainly used in domestic greenhouse crops and small crop or long-range barrel type spray, but the researches about the effect of orchard environment application are very few.In this paper, on the basis of existing orchards wind send sprayer machine, introduces the electrostatic device, for the purpose of improving the modern three-excellent orchard planting patterns and the leaf solution adhesion rate(deposition rate) inside and outside of the tree crown, the front and back of the leaves, and reducing the target solution floating loss, the paper analyzes the theory of electrostatic spray, determines the main factors that affect the performance of spray, optimizes and determines the reasonable spraying parameters by the test which provides theory basis for the design of the orchard wind send electrostatic sprayer machine. In this paper the concrete work includes:1.Analyse the theory of air electrostatic spray technology, to design an air assisted electrostatic spraying device which is formed mainly by air hydraulic sprayer and electrostatic spray device.2.In order to work normally under the condition of meeting the needs of axial flow fan in line with the normal atomization and further blowing wind speed and wind pressure requirements, using Pro/E to establish 3-D model of axial fan impeller, blade, using ANSYS Workbench finite element analysis software to anylyse the static and dynamic of the leaves, and the analysis result shows that, the axial flow fan working in the rated operation condition of wind speed V=9m/s, wind load under the condition of P=32.4Pa, the design of axial fan blade will not occur resonance and bending failure with impeller and its components, compared with the design requirements.3.According to the operation quality of air assisted orchard sprayer machine named NY/T992-2006, and the method for plants protection of general test named JB/T9782-1999, conducts the air electrostatic spraying performance test which including indoor test and outdoor test, indoor tests include the droplet diameter, spray angle, spray volume level uniformity of the nozzle; outdoor tests include testing the wind speed of the fan outlet under the different rotating speed, and the wind speed, the spray painting, the deposition of spray droplet and the penetration between horizontal and vertical position of the fan of different distance.4.On the basis of above working, compared with the non electrostatic spray, and ultimately get the best parameter to spray of the air assisted electrostatic spraying device : the spray machine adopts an axial flow, The optimal speed of axial flow fan is 2000r/min, the electrostatic spray voltage is 10 KV, the spray pressure is 0.5MPa, the right horizontal distance of spray painting is 2.0m~3.0m, the vertical height is 1.8m~2.2m, the target crop height is less than 3m. Droplet deposition increased by more than 40%, the droplet drift rate decreased by 62.6%.