VariTarget – A New Nozzle with Variable Flow Rate and Droplet Optimization

A new nozzle with flow rate and droplet size control capability was developed and marketed. The design of the VariTarget nozzle is a combination of variable-area pre-orifice and variable-area spray orifice. Both areas of the pre-orifice and spray orifice vary during operation for various flow rates. This keeps droplet sizes optimized and sprays angle constant over the variation in flow rate. The nozzle comprises two main components, a spray tip with a variable-area spray orifice and a metering assembly with variable-area pre-orifices. The spray tip comprises two levers controlling the opening of the spray orifice. One end of the metering assembly is a wedge with two variable-depth grooves. The position of the wedge on the two levers determines the opening of the spray tip and the pre-orifice. One end of the metering assembly is attached to a diaphragm, which is used to control the movement of the metering assembly through the balance of liquid pressure and spring force. As pressure varies from 15 to 50 PSI, flow rate of the VariTarget nozzle varies from .15 to .80 GPM and the VMD of droplets varies from 425 to 325 microns for systemic pesticides; and from 240 to 200 microns for contact pesticides. The spray angle is 110o and spray distribution is consistent over the range of flow rate. The response time to rate changes is less than 0.25 seconds. The nozzle fits conventional nozzle bodies, adaptable to conventional spraying systems, and can be used with pressure regulators or automatic rate controllers.