| High efficient and low pollution pesticide application technology is the development trend of plant protection machinery.The operation of plant protection machinery is different from the other agricultural machinery and the application effect of plant protection machinery is correlated with the control effect and the safety of the operator and agricultural products.So,the detection and analysis after the pesticide application is one of judgment standards to evaluate whether the work parameter of plant protection machinery is reasonable,or its work effect is fit.The cold aerosol sprayer is a new and high efficient plant protection machinery. When it works,the diameter of droplet is about 20μm and the droplet can be suspended in the air for long time.So,the research of the distribution law of concentration field in the airtight space has important significance to evaluate the spray effect and the work parameter of the cold aerosol sprayer.This article proposed to use the improved container which collects the air samples after the pesticide application of cold aerosol sprayer in the awning room. First,the experiment was done in length,width and height to research the distribution law of concentration in a straight line.Then,35 air samplers were used in the level of 1.5m in the different location,and establishes curved surface of concentration of pesticide fog based on cubic spline interpolation through Matlab to research the distribution law of concentration in a horizontal level.Finally,the influence of wind speed to the fog distribution was researched.Through the experimental analysis,this article has drawn following conclusion:(1) In length:the pesticide concentration become maximum at about 12～14m in the front of the nozzle,and it has a wave trough at about 2m in the front of the nozzle. The effective regional of cold aerosol sprayer was about 42m,from about 10m in the back of the nozzle to 32m in the front of the nozzle,and when it exceeds this area,the concentration declines faster.(2) In width:the pesticide concentration was lower in the middle of airtight space than the sides of it.This phenomenon becomes more obvious when it is close to the nozzle.(3) In height:because of the deposition of the droplet,the concentration of pesticide fog becomes smaller with height increase,but this change is not obvious, and the distribution of pesticide fog is more uniform.(4) The influence of wind speed to the fog distribution:①The influence of wind speed to the pesticide concentration changed with time in single point:it had no obvious effect on the pesticide concentration changed with time at the spraying time;But after the spraying time,the pesticide concentration was larger in the higher speed wind in the same time.②The influence of wind speed to the fog distribution in multi-point:at the wind speed of 50Hz power frequency,the concentration of pesticide fog is higher than the other wind speed,and the distribution of pesticide fog is more uniform at the wind speed of 50Hz power frequency. |
