Spray system pressure and ratio control

Patent metadata

Field	Value
Publication number	US-2016167066-A1
Application number	US-201414905197-A
Country	US
Kind code	A1
Filing date	Jul 18, 2014
Priority date	Jul 19, 2013
Publication date	Jun 16, 2016
Grant date	—

Abstract

A control method for a two-component spray system having first and second pumps for separate fluid components includes registering a target spray pressure, registering a target primary-to-secondary spray component flow ratio, sensing an output pressure of the first pump, controlling the first pump to a first speed set via a proportional-integral-derivative loop using the sensed output pressure and the target spray pressure, and controlling the second pump to a second speed equal to the first speed multiplied by the target primary-to-secondary spray component flow ratio.

First claim

1 . A spray system comprising:
a first fluid source configured to provide a first fluid; a second fluid source configured to provide a second fluid; a sprayer configured to combine and spray the first and second fluids; a first pump configured to pump the first fluid at a variable first pumping speed from the first fluid source to the sprayer; a second pump configured to pump the second fluid at a variable second pumping speed from the second fluid source to the sprayer; a first pressure sensor disposed to sense a first output pressure of the first pump; and a controller configured to control the first pumping speed via a proportional-integral-derivative loop using the sensed first output pressure and a target spray pressure, and configured to command the second pumping speed to the first pumping speed times a target primary-to-secondary spray component flow ratio.

2 . The spray system of claim 1 , wherein the first and second fluid sources are pre-pressurized.

3 . The spray system of claim 2 , wherein the first and second fluid sources are pre-pressurized to at least 50% of the target pressure.

4 . The spray system of claim 1 , further comprising a local operator interface configured to receive the target spray pressure and the target primary-to-secondary spray component flow ratio from a user.

5 . The spray system of claim 1 , wherein the first fluid comprises a paint.

6 . The spray system of claim 1 , wherein the second fluid comprises a paint catalyst.

7 . The spray system of claim 1 , wherein the first fluid source is connected to the first pump via a pump manifold disposed to accept multiple source lines.

8 . The spray system of claim 1 , wherein the first and second pumps are positive displacement pumps.

9 . The spray system of claim 8 , wherein the first and second pumps are balanced proportioning pumps.

10 . A control method for a two-component spray system having first and second pumps for separate fluid components, the method comprising:
registering a target spray pressure; registering a material-specific target primary-to-secondary spray component flow ratio; sensing an output pressure of the first pump; instructing the first pump to deliver a first fluid at a first speed set via a proportional-integral-derivative loop using the sensed output pressure and the target spray pressure; and instructing the second pump to deliver a second fluid at a second speed equal to the first speed multiplied by the target primary-to-secondary spray component flow ratio.

11 . The control method of claim 10 , wherein registering the target pressure comprises receiving a user input.

12 . The control method of claim 11 , wherein registering the target pressure comprises receiving a user selection from among a plurality of preset pressure options.

13 . The control method of claim 11 , wherein the user input specifies the fluid components.

14 . The control method of claim 10 , further comprising identifying a failure condition in response to a persistent difference greater than a threshold value between the sensed output pressure and the target spray pressure.

Assignees

• Graco Minnesota Inc

Inventors

• Fehr David L
• Ingebrand John R
• Shaffer Jeffrey U

Classifications

• B05B7/1254 Primary

  the controlling means being fluid actuated · CPC title

• B05B7/2497

  several liquids from different sources being supplied to the discharge device · CPC title

• F04B15/02

  the fluids being viscous or non-homogeneous · CPC title

• F04B13/00

  Pumps specially modified to deliver fixed or variable measured quantities · CPC title

• B05B15/55

  using cleaning fluids · CPC title