Title: Liquid scanner nozzle and method
Abstract: A full coverage area spray device has an oscillation chamber. Chamber end plates have a diameter D and the distance between the inlet and outlet apertures is L and ratio L/D determines the spray pattern and is adapted to support a basic toroidal flow pattern that remains captive within the confines of the oscillation chamber. The toroid spins about its cross-sectional axis and being supplied energy from the jet of liquid issued into the oscillation chamber. The toroidal flow pattern has diametrically opposed cross-sections which alternate in size to cause the jet to move in radial paths and also in tangential direction and thereby choose a different radial path at each sweep, whereby there is a random sweeping of the jet issuing from the outlet aperture over the area.
Patent Number: 6,938,835 Issued on 09/06/2005 to Stouffer
| Inventors:
|
Stouffer; Ronald D. (Silver Spring, MD)
|
| Assignee:
|
Bowles Fluidics Corporation (Columbia, MD)
|
| Appl. No.:
|
021270 |
| Filed:
|
December 19, 2001 |
| Current U.S. Class: |
239/242; 239/589.1; 137/808 |
| Intern'l Class: |
B05B 003/16 |
| Field of Search: |
239/242,589,589.1
137/808,810,813,833
|
References Cited [Referenced By]
U.S. Patent Documents
| 4151955 | May., 1979 | Stouffer.
| |
| 4508267 | Apr., 1985 | Stouffer.
| |
| 4721251 | Jan., 1988 | Kondo et al.
| |
| 5060867 | Oct., 1991 | Luxton et al.
| |
| 5213269 | May., 1993 | Srinath et al.
| |
| 5213270 | May., 1993 | Stouffer et al.
| |
| 5769624 | Jun., 1998 | Luxton et al.
| |
| Foreign Patent Documents |
| WO 99/2602/1 | May., 1999 | WO.
| |
Primary Examiner: Nguyen; Dinh Q.
Attorney, Agent or Firm: Zegeer; Jim
Parent Case Text
REFERENCE TO RELATED APPLICATION
The present application is the subject of provisional application No. 60/256,471
filed Dec. 20, 2000 entitled SCANNER NOZZLE.
Claims
1. A full coverage area spray nozzle comprising an oscillation chamber having
an upstream end plate and a downstream end plate, an inlet aperture d
1
in said upstream end plate coupled to a source of pressurized liquid to be sprayed
on said area and issuing a jet of liquid into said oscillation chamber, an outlet
aperture d
2 at said downstream end for issuing a jet of said pressurized
liquid to ambient, the walls of said oscillation chamber being defined by a line
revolved about an axial line passing through said inlet aperture and said outlet
aperture d
2, said end plates have a diameter D and the distance between
said inlet and outlet apertures is L and ratio L/D determines the spray pattern
and is adapted to support a basic toroid flow pattern that remains captive within
the confines of said oscillation chamber, said toroid spinning about its cross-sectional
axis and being supplied energy from the jet of liquid issued into said oscillation
chamber, said toroidal flow pattern having diametrically opposed cross-sections
which alternate in size to cause the jet to move in radial paths and also in tangential
direction and thereby choose a different radial path at each sweep, whereby there
is a random sweeping of the jet issuing from said outlet aperture over said area.
2. The nozzle defined in claim 1 wherein said downstream end plate is dome shaped.
3. The nozzle defined in claim 1 wherein said downstream end plate is dimple shaped.
4. The nozzle defined in claim 1 wherein said downstream end plate is flat shaped.
5. The nozzle defined in claim 1 wherein said apertures d
1 and d
2
have sharp edges.
6. The nozzle defined in claim 1 wherein the ratio L/D is adjustable.
7. The nozzle defined in claim 1 wherein the distance L between said apertures
d
1 and d
2 is adjustable.
8. A full coverage area spray nozzle comprising an oscillation chamber having
an upstream end plate and a downstream end plate, an inlet aperture d
1
in said upstream end plate coupled to a source of pressurized liquid to be sprayed
on said area and issuing a jet of liquid into said oscillation chamber, an outlet
aperture d
2 in said downstream end plate for issuing a jet of said pressurized
liquid to ambient, the walls of said oscillation chamber being defined by a line
revolved about an axial line passing through said inlet aperture and said outlet
aperture d
2, said end plates having a diameter D and the distance between
said inlet and outlet apertures is L and ratio L/D determines the spray pattern,
said oscillation chamber causing a basic toroid flow pattern that remains captive
within the confines of said oscillation chamber, said toroid spinning about its
cross-sectional axis and being supplied energy from said jet of liquid issued into
said oscillation chamber, said toroidal flow pattern having diametrically opposed
cross-sections which rotate about said axial line and alternate in size to cause
said jet to move in a plurality of radial paths and thereby randomly traverse a
different radial path at each sweep, whereby there is a random sweeping of the
jet issuing from said outlet aperture over said area.
9. The nozzle defined in claim 8 wherein said downstream end plate is dome shaped.
10. The nozzle defined in claim 8 wherein said apertures d
1 and d
2
have sharp edges.
11. The nozzle defined in claim 8 wherein the ratio L/D is adjustable.
12. The nozzle defined in claim 8 wherein the distance L between said apertures
d
1 and d
2 is adjustable.
13. A full coverage area liquid spray device comprising oscillation chamber,
apertured end plates having a diameter D and the distance between the inlet and
outlet apertures is L and ratio L/D determines the spray pattern and is adapted
to support an oscillatory toroidal flow pattern that remains captive within the
confines of said oscillation chamber and spins about its cross-sectional axis and
being supplied energy from the jet of liquid issued into the oscillation chamber,
said toroidal flow pattern has diametrically opposed cross-sections which alternate
in size to cause the jet to sweep in a plurality of different radial paths and
also in tangential direction and thereby choose a different radial path at each
sweep, whereby there is a random sweeping of the jet issuing from the outlet aperture
over the area.
Description
BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION
The present invention relates to a three-dimensional (3-D) scanning nozzle operating
in the liquid-to-air mode, and more particularly, to a 3-D scanning nozzle in which
a single jet has long wavelengths so that slugs of fluid persist for greater distances
from the nozzle thereby providing superior cleaning for hard surfaces by impact
and abrasion.
In the past, full coverage sprays have been accomplished by fluidic oscillators
that sweep sheets (e.g. see Stouffer U.S. Pat. No. 4,151,955) or by mechanically
traversing a sweeping jet over the target surface (as is done in the case of some
headlamp washers). Most of the current cleaning jets distribute energy by spreading
the jet and rely on wand traversing to providing further distribution. Superior
cleaning has been shown by sweeping-jets issued from a fan nozzle of the type shown
in Stouffer U.S. Pat. No. 4,508,267 over that of a spread jet, with static (non-sweeping
nozzle on headlamp cleaning nozzles.
A single, concentrated jet that is time-shared over an area is superior to a
static,
multi-jet and should be better than nozzles that sweep just like a fan.
THE PRESENT INVENTION
In order to obtain a full-coverage spray pattern that is also more uniform in
both pattern distribution as well as droplet size, the present invention relies
on a type of fluidic oscillator that produces a random scan in both radial and
tangential directions.
The invention features:
A full coverage area spray nozzle having an oscillation chamber bounded by an
upstream
end plate and a downstream end plate. An inlet aperture d
1 in the upstream
end plate is coupled to a source of pressurized liquid to be sprayed on the area
and issuing a jet of liquid into the oscillation chamber and an outlet aperture
d
2 at the downstream end for issuing a jet of the pressurized liquid
to ambient. The walls of the oscillation chamber are defined by a line revolved
about an axial line passing through the inlet aperture d
1 and the outlet
aperture d
2. The end plates have a diameter D and the distance between
the inlet and outlet apertures is L and the ratio L/D determines the spray pattern.
The oscillation chamber is adapted to support a basic oscillatory toroidal flow
pattern which remains captive within the confines of the oscillation chamber. The
toroid spins about its cross-sectional axis and is supplied with energy from the
jet of liquid issued into the oscillation chamber. The toroidal flow pattern has
diametrically opposed cross-sections which alternate in size to cause the jet to
move in radial paths and also in tangential direction and thereby moves in a different
radial path at each sweep, whereby there is a random sweeping of the jet issuing
from the outlet aperture over the area.
In one preferred embodiment, the downstream end plate is dome shaped.
In another embodiment, the downstream end plate is dimple-shaped.
In another embodiment, the downstream end plate is flat-shaped.
Preferably, the apertures d
1 and d
2 have sharp edges.
In another embodiment, the distance L between inlet and outlet apertures is adjustable.
The object of the invention is to provide an improved 3-D scanner nozzle which
is robust in operation, easy to construct and has wide design flexibility and is
capable of adaptation to numerous uses.
DESCRIPTION OF THE DRAWINGS
The above and other objects, advantages and features of the invention will become
more apparent when considered with the following specification and accompanying
drawings wherein:
FIG. 1 is a schematic illustration of a preferred embodiment of the invention
in which the configuration is a figure of revolution, a cylinder with a dome-top
or end plate,
FIG. 2 is a diagrammatic illustration of a second embodiment of the invention
in which the output aperture is in a flat-topped member or end plate,
FIG. 3 is a diagrammatic illustration of a third embodiment of the invention
in which the outlet aperture is in a dimpled-top member or end plate,
FIG. 4 is a diagrammatic illustration of the preferred embodiment of FIG. 1
showing a functional aspect of the invention,
FIG. 5 is a diagrammatic illustration of the random sweeping of jet slugs produced
by the invention over an area, and
FIG. 6 is a diagrammatic illustration of a length adjustable oscillation chamber.
DETAILED DESCRIPTION OF THE INVENTION
The configuration shown in FIGS. 1 and 4 is a figure of revolution: a cylinder
10 with a domed-top endplate
11. The top end plate
11 and
bottom end plate
12 have round orifices or apertures d
2 and d
1,
respectively, which, preferably, are closely sharp edged or chamfered as shown
at Cd
1 and Cd
2. As shown in FIG. 4, the oscillating toroid
T is smallest on the left side T
L and largest on the right side T
R,
but this condition changes or alternates. The toroid flow pattern remains captive
within the confines of the oscillation chamber, spinning about its cross-sectional
axis and being supplied energy from the liquid jet issuing from orifice d
1.
The toroidal flow pattern (also shown in FIGS. 2 and 3) has diametrically opposed
cross-sections which alternate in size to cause the jet to move in radial paths
and also in tangential directions and thereby choose or traverse a different radial
path at each sweep. As a result, there is a random sweeping of the jet issuing
from the outlet area, as illustrated in FIG. 5.
Use of the domed top
11 has been found to double the output cone angle
over that of a flat top. It is believed that the reason for this is that the dome
shape gives the most unfavorable angle for recirculation on the weak side. All
of the outlets disclosed herein promote recirculation on the side to which the
jet is deflected, but the dome shape has the most unfavorable angle to promote
recirculation on the opposite side, thereby allowing a larger deflection of the jet.
Referring to FIG. 2, the downstream end plate F
T is flat, and
in FIG. 3 the downstream endplate D
T is dimpled with the outlet aperture
d
2" in the dimple D. The toroidal flow patterns are essentially the
same. In FIGS. 2 and 3, the left toroidal sectional views and right toroidal sectional
views are shown as at about the same size.
In FIG. 5, the randomly directed sweeping single jet quickly covers the area A
in a substantially uniform distribution and also substantially uniform slugs of
liquid. Thus, the scanning jet automatically and continually distributes the jet's
effects (cleaning, for example) over an area, even if the wand (not shown) in which
the nozzle is mounted were halted.
Various configurations of the scanner nozzle of this invention in the liquid-to-air
mode disclose potential advantages beyond the basic one of the 3-D scanning of
a single jet with long wavelengths.
Robustness
The nozzle of this invention has liberal tolerances to some large changes to
its basic geometry. Almost any inlet nozzle geometry may be used, from a straight
tube to a converging nozzle to a sharp edged orifice as shown in FIG. 1. Above
a certain absolute value of the chamber dimensions L and D, the performance changes
very little. And to defeat the oscillation takes large changes of certain dimensions
in specific combinations.
The axisymmetric chamber C works, but it is not necessary to be axisymmetric
for oscillation. The shape of the chamber can have asymmetry and still function
to support oscillation. For instance, the outlet plane can be askew relative the
chamber axis, or the chamber axis can be curved or the chamber cross-section may
be asymmetrical.
Ease of Construction
A preferred embodiment is simply a chamber C having an integral floor
12
with a sealed lid
11, wherein the floor has a liquid inlet opening d
1
to ingress fluid and the domed-lid or endplate
11 has a hole d
2 to
egress fluid to ambient. The ingress hole or aperture is connected to a source
15 of liquid under pressure via a valve not shown. The cross-section of
the chamber need not be round, but if it is selected, simple, reliable sealing
techniques may be practiced.
The chamber length can be varied to change the L/D ratio, as shown in FIG. 6.
The upper chamber portion UCF is telescoped over the lower chamber portion LCP.
A gear rack GR on upper chamber portion UCP is engaged by gear G, which, upon rotation
thereof by knob K adjusts the distance L between the input and output apertures
or orifices.
Design Flexibility
Several geometrical parameters appear to be relatively independent and correlate
with specific performance. The L/D of the chamber appears to determine whether
the spray pattern is planar or full coverage. For L/D>1, a three-dimensional
pattern results, whereas a planar spray is produced when L/D is near to 1.
If the design is approached from smaller chamber sizes proceeding to larger chamber
sizes with respect to the inlet size, performance changes rapidly until L and D
each approach about 10d
1 beyond which the L and D have little effect
on the performance except for the ratio L/D which appears to control the planar
vs 3-D mode.
Changing L and D but keeping L/D constant maintains the fan/cone angle constant.
Increase L beyond about L=10d
1 with other geometry held constant,
does not materially affect performance.
Uses
This configuration with its implied simple construction (can and lid) is geometrically
adaptive to many applications. As a spray device it covers an area (circular or
a line) by sweeping a single jet. Although the detailed shape of the spray pattern
is complex, the effective wavelength is long so that slugs of fluid persist for
greater distances from the nozzle exit. This slug-keeping characteristic has been
shown to be superior for cleaning of hard surfaces by impactive abrasion.
Some specific uses include (1) changing from planar to full coverage by adjusting
the chamber's length (L) and (2) permitting an adjustable spray pattern axis by
changing the axis of the output member (lid).
It is believed that a flattened version (elliptical chamber cross-section) will
operate to produce fans to various thickness depending on the cross-section's length-to-width ratio.
While the invention has been described in relation to preferred embodiments
of the invention, it will be appreciated that other embodiments, adaptations and
modifications of the invention will be apparent to those skilled in the art.
*
