How adjuvants influence spray formation with different hydraulic nozzles

Abstract Formation of sprays by five hydraulic nozzles (standard flat fan, pre-orifice, hollow cone, low-pressure and evenspray nozzles) were investigated in order to establish whether the proven effects of adjuvants on sprays from a standard flat fan nozzle are reproduced by other hydraulic nozzles. Measurements were made of droplet size and velocities and spray volume distribution patterns with seven spray liquids (water alone or water plus one of six adjuvants). All spray liquids had similar spray formation mechanisms through each of the nozzles and similar effects on liquid sheet length and spray volume distribution patterns. However, changes in droplet size were not the same for all nozzles, with the hollow cone and pre-orifice nozzles showing substantial differences. The resulting problems in developing a model to predict the effects of adjuvants on droplet sizes and drift potential are discussed.