During pesticide spraying, some of the smallest or slowest droplets do not reach the target and may contribute to spray drift. Therefore, it is important to characterize droplet size and velocity close to the nozzle e...During pesticide spraying, some of the smallest or slowest droplets do not reach the target and may contribute to spray drift. Therefore, it is important to characterize droplet size and velocity close to the nozzle exit. The aim of this study was to contribute to the comprehension of spray formation. Surfactant influence on spray characteristics was studied by comparing water spray with sprays containing three different surfactants, Two nozzles including a classical hollow cone nozzle ATR （Albuz, France） and an air-induced hollow cone nozzle TVI which is a low-drift nozzle （Albuz, France） were chosen. Radial profiles of the axial velocity component and Sauter mean diameter at two axial distances from the nozzle exit were measured using a Phase Doppler Particle Analyzer （PDPA）. Results showed that sprays issued from ATR and TVI nozzles were very different, even when water was sprayed. Effect of adding surfactant depended on the nozzle type. Sheet thickness was reduced by adding Elton and Heliosol regardless of the nozzle type. They reduced spray angle of ATR nozzle spray but did not affect that of YVI nozzle. Break-Thru has a slight effect when sprayed through the ATR nozzle, but it has the most pronounced effect on the SMD when sprayed through the TVI nozzle.展开更多
文摘During pesticide spraying, some of the smallest or slowest droplets do not reach the target and may contribute to spray drift. Therefore, it is important to characterize droplet size and velocity close to the nozzle exit. The aim of this study was to contribute to the comprehension of spray formation. Surfactant influence on spray characteristics was studied by comparing water spray with sprays containing three different surfactants, Two nozzles including a classical hollow cone nozzle ATR （Albuz, France） and an air-induced hollow cone nozzle TVI which is a low-drift nozzle （Albuz, France） were chosen. Radial profiles of the axial velocity component and Sauter mean diameter at two axial distances from the nozzle exit were measured using a Phase Doppler Particle Analyzer （PDPA）. Results showed that sprays issued from ATR and TVI nozzles were very different, even when water was sprayed. Effect of adding surfactant depended on the nozzle type. Sheet thickness was reduced by adding Elton and Heliosol regardless of the nozzle type. They reduced spray angle of ATR nozzle spray but did not affect that of YVI nozzle. Break-Thru has a slight effect when sprayed through the ATR nozzle, but it has the most pronounced effect on the SMD when sprayed through the TVI nozzle.
