How adjuvants influence spray formation with different hydraulic nozzles

Formation of sprays by five hydraulic nozzles (standard flat fan, pre-orifi ce, hollow cone, low-pressure and evenspray nozzles) were investigated in o rder to establish whether the proven effects of adjuvants on sprays from a standard flat fan nozzle are reproduced by other hydraulic nozzles. Measure ments were made of droplet size and velocities and spray volume distributio n patterns with seven spray liquids (water alone or water plus one of six a djuvants). All spray liquids had similar spray formation mechanisms through each of the nozzles and similar effects on liquid sheet length and spray v olume 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 pr edict the effects of adjuvants on droplet sizes and drift potential are dis cussed. (C) 1999 Elsevier Science Ltd. All rights reserved.