| Using chemical pesticide is a main and high-efficiency measure in curing the pests and diseases. We spray 1 million tons of agrochemicals and Pesticides and 100 million ton of liquid medicine to farm each year in China. Only 20%~30% liquid medicine injected out can reach the target. Low volume spraying technology was researched by the way to improve the efficiency of small size droplets and control spray drift. We researched the current situation on Pharmaceutical Machinery and anti-drift technique. Based on this, we think it is very necessary to study the technology of spraying with the air assistance-sleeve boom sprayer and the corresponding machine .The machine consists of air-bag boom systems, hydraulic transmission gear and speed regulation device.Use the 3D design software SolidWorks drew each parts and the whole body of the machine in three-dimensional entity, and it can be seen more intuitionisticly. Use the Computational Fluid Dynamics software FLUENT to simulate inner air flow field of the air-bag, first, use the prefix processor GAMBIT founded models,plotted out gridding and created gridding files for the two parts; then transmitted files the prefix processor created into FLUENT, enacted boundary condition and chose appropriate mathematics model, simulated the velocity contour line,velocity vectors and flown line track of the inner air flow field, analyzed the results and improved the structure of the irrationality part, and once again numerical simulate the inner air flow field of this newly improved part. The finally improved structure, simulated result indicate that the flow field and the speed distribution are all reasonable. Decided the power transition style: tractor oil pump-oil hydraulic motor-axial flow fan, then supply air to the air-bag. In order to accommodate the environmental conditions, we control hydraulic oil flow rate to Geared Motor.Use AutoCAD drew the drawing of each parts and entire assembly drawing,and manufactured the fan and air-bag. Then fit them to the air-assisted boom sprayer machine. By doing some laboratory experiments we tested the analog simulation, and also verified the theory correctness. Tested the rationality of chooseing different air-assisted velocity according to different environmental conditions. From the experiments we can see, using the air-assisted technology play an important part in working. By using distance to the centre of mass (Dc), we well evaluate the systems anti-drift function. The air curtain do well effect to both general nozzle and anti-drift nozzle. Test results show that the air-assisted system is effective in reducing the drift rate and enhance the use rate of pesticide and reduce the environment pollution caused by pesticide. We can control the axial fan,surrogate and protrude, and fold the boom at a high rate of speed. The air speed can be set up at 20 m/s, 25 m/s and 30 m/s. The air curtain do well effect to both general nozzle and anti-drift nozzle. Moreover, the Dc was greater in higher air pressure and lower air speed than in lower air pressure and higher air speed, which indicated that the pressure have more effect on Dc through the change of droplet size than wind speed. Therefore, the air-assisted sprayer was better for the droplet intimidation sedimentation than other shields. Because of using the twin fluid air–blast nozzle and the twice-atomizing, the droplet has a better deposition and distribution in the spray width. Therefore, the air-assisted sprayer was better for the droplet intimidation sedimentation than other shields. From the secondary-atomization result and reduced drift rate we can see,we get a good effect. The system played its prospective rule. |
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