Low pressure spray tip configurations

Patent metadata

Field	Value
Publication number	US-2016303585-A1
Application number	US-201615132894-A
Country	US
Kind code	A1
Filing date	Apr 19, 2016
Priority date	Apr 20, 2015
Publication date	Oct 20, 2016
Grant date	—

Abstract

A spray tip configuration for a low pressure fluid sprayer is presented. The spray tip configuration comprises an inlet orifice configured to receive a fluid and to produce a turbulent flow at a known operating point. The spray tip configuration also comprises an outlet orifice configured to emit the fluid in a spray pattern at a turbulence intensity. The spray tip configuration also comprises a passageway fluidically coupling the inlet orifice to the outlet orifice, with a plurality of portions configured to produce the turbulence intensity at the outlet orifice. The passageway comprises a first portion comprising an expansion chamber configured to provide an expanding cross-section from a first portion first end to a first portion second end. The passageway also comprises a second portion comprising a first hydraulic diameter, wherein the second portion is fluidically coupled, on a second portion first end, to the first portion second end. The passageway also comprises a third portion comprising a second hydraulic diameter, wherein the third portion fluidically couples to the second portion at a third portion second end. The passageway also comprises a fourth portion comprising a spray tip, wherein the fourth portion is fluidically coupled, on a fourth portion first end, to a third portion second end, and, on a fourth portion second end, to the outlet orifice.

First claim

What is claimed is:

1 . A spray tip configuration for a low pressure fluid sprayer comprising:
an inlet orifice configured to receive a fluid and produce a turbulent flow at a known operating point; an outlet orifice configured to emit the fluid in a spray pattern at a turbulence intensity; and a passageway fluidically coupling the inlet orifice to the outlet orifice, the passageway comprising a plurality of portions configured to produce the turbulence intensity at the outlet orifice, the plurality of portions comprising:
a first portion comprising an expansion chamber configured to provide an expanding cross-section from a first portion first end to a first portion second end;
a second portion comprising a first hydraulic diameter, wherein the second portion is fluidically coupled, on a second portion first end, to the first portion second end;
a third portion comprising a second hydraulic diameter, wherein the third portion fluidically couples to the second portion at a third portion second end; and
a fourth portion comprising a spray tip, wherein the fourth portion is fluidically coupled, on a fourth portion first end, to a third portion second end, and, on a fourth portion second end, to the outlet orifice.

2 . The spray tip configuration of claim 1 , and further comprising:
a fifth portion comprising a convergent cross-section, wherein the third portion is fluidically coupled, on a fifth portion first end, to a second portion second end.

3 . The spray tip configuration of claim 1 , and further comprising:
a sixth portion comprising a third hydraulic diameter, wherein the sixth portion is fluidically coupled to the first portion first end.

4 . The spray tip configuration of claim 2 , and further comprising:
a seventh portion comprising a fourth hydraulic diameter, wherein the third hydraulic diameter is fluidically coupled between the second portion and the fifth portion, such that the third hydraulic diameter provides the fluidic coupling between the second portion, on a seventh portion first end, and the fifth portion, on a seventh portion second end.

5 . The spray tip configuration of claim 1 , wherein the spray pattern is substantially free of tailing effects.

6 . The spray tip configuration of claim 1 , wherein a length of the passageway is configured to provide a turbulent fluid flow with a maximum turbulence intensity that decays to the turbulence intensity at the outlet interface.

7 . The spray tip configuration of claim 6 , wherein the turbulence intensity of the turbulent fluid flow comprises an at least 5% turbulence intensity.

8 . The spray tip configuration of claim 6 , wherein the turbulence intensity of the turbulent fluid flow comprises a less than 15% turbulence intensity.

9 . The spray tip configuration of claim 6 , wherein an axial length, hydraulic diameter, and net angle of expansion of one of the plurality of portions is designed such that it is configured to induce a turbulent flow with designed turbulence intensity based on a known viscosity of the fluid.

10 . The spray tip configuration of claim 1 , wherein low pressure comprises fluid flow below 2,000 pounds per square inch (PSI).

11 . The spray tip configuration of claim 1 , wherein low pressure comprises fluid flow below 1,000 pounds per square inch (PSI).

12 . A method for spraying a fluid at low spray pressures, the method comprising the steps of:
receiving, at an inlet of a spray gun, the fluid pressurized at a low spraying pressure; actuating the spray gun such that fluid is discharged in an even spray pattern, substantially free of tailing effects; and wherein the spray gun comprises a pre-orifice spray tip configuration with a fluid flow channel, and wherein the fluid flow channel comprises a first portion with a first hydraulic diameter, coupled to a second portion with an expanding cross-section, coupled to a third portion with a second hydraulic diameter, coupled to a fourth portion with a contracting cross-section, coupled to a fifth portion with a third hydraulic diameter, coupled to a spheroid portion.

13 . The method of claim 12 , wherein a sixth portion with a fourth hydraulic diameter is coupled, on a first end, to the second portion and, on a second end, to the third portion.

14 . The method of claim 13 , and further comprising:
selecting the spray tip configuration based on a known viscosity of the fluid.

15 . The method of claim 14 , wherein selecting comprises selecting a spray tip configuration that will a turbulent fluid flow with an at least 5% turbulence intensity, at an outlet of the spray gun.

16 . The method of claim 15 , wherein low pressure comprises a pressure below 2000 PSI.

17 . The method of claim 16 , wherein low pressure comprises a pressure below 1000 PSI.

18 . A spray tip configuration comprising:
an inlet orifice configured to receive a fluid and generate a turbulent flow; an outlet orifice configured to emit the fluid in a spray pattern with a turbulence intensity less than a maximum turbulence intensity experienced by the fluid within a passageway fluidically coupling the inlet orifice to the outlet orifice; and wherein the passageway comprises a turbulence feature configured to tune the turbulence intensity to the turbulent intensity, wherein the passageway comprises:
a first portion comprising an expansion chamber with a first axial distance, a first effective radius and a second effective radius, wherein the first effective radius is shorter than the second effective radius, wherein the first portion is configured to receive the fluid to be sprayed from the inlet orifice;
a second portion comprising a first hydraulic diameter with a second axial distance and a third effective radius, wherein the second portion is fluidically connects to the first portion at a first interface;
a third portion comprising a second hydraulic diameter with a third axial distance and a fourth effective radius, wherein the second portion fluidically connects to the fourth portion at a second interface; and
a fourth portion comprising a spheroid with a spheroid radius, wherein the third portion fluidically couples, on a first end, to the fourth portion at a third interface, and wherein the fourth portion comprises the outlet orifice at a second end.

19 . The spray tip configuration of claim 18 , wherein the second interface comprises:
a fifth portion comprising a converging chamber, with a fourth effective radius, a fifth effective radius and a fourth axial distance, wherein the fifth radius is shorter than the fourth radius, wherein the second portion fluidically connects to the fifth portion at a fourth interface.

20 . The spray tip configuration of claim 18 , and further comprising:
a sixth portion comprising a third hydraulic diameter with a seventh effective radius and a fifth axial distance, wherein the sixth portion fluidically couples to the first portion at a fifth interface such that fluid received from the inlet orifice passes through the sixth portion before being received by the first portion.

21 . The spray tip configuration of claim 18 , wherein the first interface comprises a seventh portion, wherein the seventh portion comprises a fourth hydraulic diameter with an eighth effective radius and a sixth axial distance, such that fluid received from the second portion passes through the seventh portion before being flowing to the third portion.

22 . The spray tip configuration of claim 18 , whe

Assignees

• Wagner Spray Tech Corp

Inventors

• Wenzel Everett A
• Rossner Ross D
• Liu Wanjiao

Classifications

• B05B1/048

  having a flow conduit with, immediately behind the outlet orifice, an elongated cross section, e.g. of oval or elliptic form, of which the major axis is perpendicular to the plane of the jet · CPC title

• B05B1/34 Primary

  designed to influence the nature of flow of the liquid or other fluent material, e.g. to produce swirl (designed to control volume of flow B05B1/30) · CPC title

• B05B9/01

  Spray pistols, {discharge devices}(B05B9/03 takes precedence) · CPC title

• B05B1/262

  with fixed deflectors · CPC title