Independent flow rate and droplet size control system and method for sprayer
First Claim
1. A flow rate and droplet size control system for a spray system including a spray liquid source, discharge pressure means associated with said spray liquid source and a nozzle assembly connected to said spray liquid source and having a nozzle tip and a nozzle valve movable between open and closed positions, which comprises:
- (a) variable duty cycle setpoint control means for opening and closing said nozzle valve and for varying the timing of the opening and closing duty cycles thereof;
(b) variable discharge pressure setpoint control means for varying the discharge pressure of said spray liquid; and
(c) an application controller including;
(1) means for receiving a flow rate setpoint;
(2) means for receiving a volume median droplet size setpoint; and
(3) a setpoint conversion subroutine for receiving said flow rate and volume median droplet size setpoints as inputs and independently controlling said variable duty cycle setpoint control means and said variable discharge pressure setpoint control means for providing independent flow rate and droplet size control.
2 Assignments
0 Petitions
Accused Products
Abstract
A flow rate and droplet size control system for a spray system including a spray liquid source, a pump, a spray liquid line and a nozzle assembly. The control system includes a setpoint conversion subroutine for independently controlling the flow rate and volume median droplet size setpoints. The control system also includes performance envelopes for various nozzle tips. An independent flow rate and droplet size control method is provided for use with the control system. A position-responsive control system receives information pertaining to the boundaries of spray zones and spray conditions, such as application rates and volume median droplet diameters associated with the spray zones. The position-responsive control system monitors the position of a spray vehicle, which can comprise a ground vehicle or an aircraft. The position-based control system changes the spray system operating conditions in response to the sprayer vehicle position. A position-based method of controlling the spray system utilizes the position-based control system.
-
Citations
56 Claims
-
1. A flow rate and droplet size control system for a spray system including a spray liquid source, discharge pressure means associated with said spray liquid source and a nozzle assembly connected to said spray liquid source and having a nozzle tip and a nozzle valve movable between open and closed positions, which comprises:
-
(a) variable duty cycle setpoint control means for opening and closing said nozzle valve and for varying the timing of the opening and closing duty cycles thereof; (b) variable discharge pressure setpoint control means for varying the discharge pressure of said spray liquid; and (c) an application controller including; (1) means for receiving a flow rate setpoint; (2) means for receiving a volume median droplet size setpoint; and (3) a setpoint conversion subroutine for receiving said flow rate and volume median droplet size setpoints as inputs and independently controlling said variable duty cycle setpoint control means and said variable discharge pressure setpoint control means for providing independent flow rate and droplet size control. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27)
-
-
28. A flow rate and droplet size control system for a spray system including a spray liquid tank, a pump fluidically connected to the tank, a spray liquid line fluidically connected to the pump and a plurality of nozzle assemblies fluidically connected to the spray liquid line and each having a nozzle valve movable between open and closed positions and a nozzle tip, which independent flow rate and droplet size control system comprises:
-
(a) a setpoint conversion subroutine receiving as inputs a flow rate setpoint and a volume median droplet size setpoint and providing as outputs a duty cycle setpoint and a liquid pressure setpoint, said setpoint conversion subroutine including means for independently controlling the flow rate and droplet size; (b) an application rate control subsystem receiving said duty cycle setpoint from said setpoint conversion subroutine and including a flow controller with function generation means for generating control signals for said nozzle valves corresponding to duty cycles thereof and a flow meter fluidically connected to said spray liquid line; (c) said flow controller, nozzle valves and flow meter forming a closed-loop feedback subsystem for maintaining a relatively constant flow rate; (d) a droplet size control subsystem receiving said liquid pressure setpoint from said setpoint conversion subroutine and including a pressure controller, pressure control means in said spray liquid line for controlling pressure therein and receiving a pressure control signal from said pressure controller and a liquid pressure transducer in said spray liquid line providing a signal corresponding to a liquid pressure therein to said pressure controller; and (e) said pressure controller, said pressure control means and said liquid pressure transducer forming a closed-loop feedback subsystem for maintaining a relatively constant liquid pressure in said spray liquid line.
-
-
29. A flow rate and droplet size control method for a spray system including a spray liquid source, variable discharge pressure control means associated with said spray liquid source and a nozzle assembly with a nozzle tip for discharging said spray liquid and a nozzle valve movable between open and closed positions, which comprises the steps of:
-
(a) inputting flow rate and volume median droplet size setpoints; (b) outputting a liquid pressure setpoint; (c) adjusting said pressure control means in response to said liquid pressure setpoint; (d) outputting a duty cycle setpoint for said nozzle valve; (e) adjusting the duty cycle of said nozzle valve assembly corresponding to the timing of cycles thereof between open and closed positions in response to said flow rate setpoint; (f) providing a setpoint conversion subroutine for receiving said flow rate and volume median droplet size setpoints as inputs; and (g) independently controlling said duty cycle setpoint and said liquid pressure setpoint for providing independent flow rate and droplet size control. - View Dependent Claims (30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56)
-
Specification