Design And Experiment Of High Clearance Boom Sprayer With Air-assisted System

Pest control is one of the most important field management operations in corn production in China.The late growth period of corn is a high incidence of pests and diseases,during this period,the corn plants are tall and the corn foliage intersects,on one hand,conventional motorized plant protection machines exist smaller models and lower chassis clearance can not enter the fields,on the other hand,the existing mechanical technology performance behind,the droplets in the corn canopy penetration is poor,spray volume,droplet drift spread caused by environmental pollution,serious waste of pesticides and corn canopy deposition is not uniform and other issues.Therefore,it is imminent to study the large-scale and high-efficiency plant protection equipment which can be suitable for the prevention and control of pests and weeds in the late stage of corn growth in China.Based on the investigation and analysis,this paper designs a high clearance boom sprayer with air-assisted system.The machine adopts full hydraulic four wheel drive,four wheel steering,diesel engine as the driving force,driving three sets of hydraulic pump work,respectively,providing power for the wheel motor and steering cylinder of the walking steering system,spray system main pump and stirring pump motor,the fan motor of the air-assisted system,the cab lift cylinder,the lift cylinder of the spray bar assembly,the fold and unfold cylinder of the spray bar assembly,and leveling cylinder,et al.The main pump extract the liquid from the main liquid tank,creates high pressure liquid,one part of which pass through the spray pressure control valve and spray switch solenoid valve group in turn,and sent to the spray nozzle of five boom for spraying,the other part return to the main liquid tank for backwater mixing.Two mixing pumps pump water from one side of the liquid tank and then piped into the other side of the liquid tank,for the two sides of the liquid tank liquid mixing.The fan motor of air-assisted system drive fan to produce high-speed airflow,through the hairdryer and the wind box below the air blown out to form a wind curtain,so as to isolate or weaken the impact of natural winds,reduce droplets drift,high-speed air flow can also be pushed to accelerate to the target,increasing the penetration of droplets on the canopy of the plant.The main research contents include: determining the overall program of high clearance boom sprayer with air-assisted system,which includes the planer type frame,chassis walking hydraulic drive system,spray bar assembly,spraying system and air-assisted system.Using Solidworks build the three-dimensional model of each component and virtual assembly according to design.Drawing 2D Drawings with AutoCAD.The velocity field of the air curtain system is simulated by ANSYS Fluent,and the structure of the air curtain system is improved.On the basis of the theoretical analysis and design,the prototype and the performance test of high clearance boom sprayer with air-assisted system are completed.The experimental results showed that spray nozzle consistency and wind speed uniformity are better;Compared with no air-assisted system,average droplet coverage rate of corn canopy was increased by 57.37%,at a height of 30,60,90,120 cm above the base level and at the top level,spray drift decreased by 61.5%?82.2%?83.0%?75.5% and 42.8%,respectively.The effects by the air-assisted system on increasing droplet deposition in the corn canopy and reducing spray drift were obvious.The machine has high clearance and reduces drift droplet deposition performance,meeting the requirements of corn protection at the middle and later growing stages.