Experimental Study On Ultrasonic Atomization

The droplet sprayed by ultrasonic atomization is characterized by less size, uniform distribution, satisfactory atomized effect, easy to control. ultrasonic atomization makes it possible that pesticide can be utilized effectively and rationally, thus reducing an unnecessary pesticide wastes, and reducing greatly the environment contamination pesticide, so as to meet the requirements of plant protection machinery splashing with low capacities. The study is a trial whether ultrasonic atomization can be applied in plant protection machinery. Ultrasonic atomization may possibly become a potential atomizing and novel way in spraying with low capacities field.3-D finite-element model of low frequency ultrasonic nozzle built, modal analyzing made, working frequency of ultrasonic atomizer chosen, atomization testing platform with low frequency bands have been developed(Two spraying ways: spurting and ejecting) .By adopting the comprehensive testing methods, PDA has been used to measure the size and distributions of ultrasonic spraying droplet. Analyses are made on the uniformity of droplet and the factors affecting the uniformity as well as distributions of single droplet. Distributing rule of droplet in entire spraying area is discovered. Four kinds of methods be delivering on size of droplet, it is found that the size of droplet can not be made clear by VMD but by NMD or average diameter. Analyses are made on the effect of power to the size of droplet, the regression equation being established between power and the size of spraying droplet. The mathematic statistical method be utilized to analyze the relationship between the size of spraying droplet and spraying ways as well as working frequency, it is found that the size of spraying droplet is not influenced by spraying ways but by working frequency. Finally, the magnitude of speed and the direction issue are analyzed.The result of examination indicated that, the amount of droplet that dimension smaller than 100 micron is about 80% of general droplet amount within 200 mms from the nozzle, and the proportion getting to 70% within 300 mms from the nozzle when the ultrasonic atomizer that the working frequency is 40kHz as well as the spraying method is point-blank is working at 47 watt. On the whole, the ultrasonic atomizer can meet the requirements of plant protection machinery splashing with precision chemical application and spraying with low capacities and it may possible be suitable for application to target spraying.