U.S. patent application number 10/837362 was filed with the patent office on 2004-12-16 for ware wash machine with fluidic oscillator nozzles.
Invention is credited to Gosis, Anatoly, Kobetsky, Robert G., Kwok, Kui-Chiu, Straughn, James M., Watson, Michael.
Application Number | 20040250837 10/837362 |
Document ID | / |
Family ID | 33303342 |
Filed Date | 2004-12-16 |
United States Patent
Application |
20040250837 |
Kind Code |
A1 |
Watson, Michael ; et
al. |
December 16, 2004 |
Ware wash machine with fluidic oscillator nozzles
Abstract
A ware wash machine includes one or more fluidic oscillator
nozzles (or other variable stream orientation nozzles) used in
connection with the dispensing of wash liquid, rinse liquid,
sanitizing liquid and/or gaseous fluids onto wares being cleaned
and/or dried and/or heated within the machine.
Inventors: |
Watson, Michael;
(Beavercreek, OH) ; Kwok, Kui-Chiu; (Gurnee,
IL) ; Gosis, Anatoly; (Palatine, IL) ;
Kobetsky, Robert G.; (Chicago, IL) ; Straughn, James
M.; (Troy, OH) |
Correspondence
Address: |
THOMPSON HINE LLP
2000 COURTHOUSE PLAZA N.E.
10 WEST SECOND STREET
DAYTON
OH
45402-1758
US
|
Family ID: |
33303342 |
Appl. No.: |
10/837362 |
Filed: |
May 1, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60478380 |
Jun 13, 2003 |
|
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Current U.S.
Class: |
134/25.2 ;
134/122R; 134/198; 134/26; 134/32; 134/64R; 134/94.1 |
Current CPC
Class: |
A47L 15/16 20130101;
A47L 15/4219 20130101; B05B 1/08 20130101; A47L 15/4278 20130101;
B05B 15/658 20180201; A47L 15/247 20130101 |
Class at
Publication: |
134/025.2 ;
134/032; 134/026; 134/094.1; 134/064.00R; 134/198; 134/122.00R |
International
Class: |
B08B 003/02 |
Claims
What is claimed is:
1. A ware wash machine, comprising: a housing including an area for
receiving wares to be washed; at least one variable stream
orientation nozzle positioned within the housing and arranged for
outputting a stream of fluid with an instantaneous direction that
varies over time relative to a nozzle axis, the stream at least
sometimes directed towards the area for contacting wares.
2. The ware wash machine of claim 1 wherein the variable stream
orientation nozzle is a fluidic oscillator nozzle connected with a
source of liquid.
3. The ware wash machine of claim 2, further comprising: at least
one liquid manifold located within the housing and acting as the
source of liquid and having a plurality of fluidic oscillator
nozzles associated therewith, each one of the fluidic oscillator
nozzles arranged for outputting an oscillating stream of liquid
towards the area for contacting wares.
4. The machine of claim 3 wherein the at least one liquid manifold
comprises at least one rinse arm supplied by a rinse liquid.
5. The machine of claim 4 wherein the rinse arm is stationary.
6. The machine of claim 5 wherein the rinse arm extends in a
direction across a conveying direction of a ware conveyor that
extends through the housing, the fluidic oscillator nozzles are
located to assure that rinse liquid covers an entire lateral area
of the conveyor, and each of the plurality of fluidic oscillator
nozzles is oriented to prevent its output oscillating stream from
interfering with oscillating streams output by adjacent fluidic
oscillator nozzles.
7. The machine of claim 5 wherein each of the fluidic oscillator
nozzles is oriented to output its oscillating stream such that
oscillating movement of ejected liquid occurs at an angle offset
from a longitudinal axis of the rinse arm.
8. The machine of claim 4 wherein the at least one rinse arm
includes a first rinse arm located below a ware conveyor that
extends through the housing and a second rinse arm located above
the ware conveyor.
9. The machine of claim 4 wherein the rinse arm is connected for
movement within the housing.
10. The machine of claim 4 wherein when the rinse arm is supplied
by rinse liquid at 20 psi, rinse liquid is collectively output by
the plurality of fluidic oscillators associated with the rinse arm
at no more than about 3 gallons/min.
11. The machine of claim 10 wherein each of the plurality of
fluidic oscillator nozzles outputs rinse liquid at no more than
about 0.3 gallons/min.
12. The machine of claim 11 wherein each of the plurality of
fluidic oscillators outputs rinse liquid with an average drop size
at least twenty-five percent greater than that output by a fanjet
nozzle having the same flow rate.
13. The machine of claim 3 wherein the manifold comprises at least
one wash arm supplied by a wash liquid.
14. The machine of claim 3 wherein the at least one liquid manifold
comprises a tubular member with a plurality of openings therein and
a multiplicity of the fluidic oscillators are each positioned in a
respective one of the openings.
15. The machine of claim 14 wherein the tubular member includes at
least one substantially flat side and the openings are located in
the substantially flat side.
16. The machine of claim 14 wherein each of the multiplicity of the
fluidic oscillator nozzles is constructed entirely of plastic.
17. The machine of claim 14 wherein each of the multiplicity of the
fluidic oscillator nozzles includes a first portion internal of the
tubular member and a second portion extending from the tubular
member, each second portion extending no more than about 0.4 inches
from the tubular member.
18. The machine of claim 14 wherein each of the multiplicity of the
fluidic oscillator nozzles is formed by first and second pieces
that are pressed together.
19. The machine of claim 18 wherein the first and second pieces are
identical to each other.
20. The machine of claim 19 wherein the first and second pieces are
press-fit together.
21. The machine of claim 20 wherein the first and second pieces are
further welded together.
22. The machine of claim 14 wherein each of the multiplicity of the
fluidic oscillator nozzles includes a portion extending from the
tubular member, and such portion includes a removal notch for
receiving a tool to facilitate prying the fluidic oscillator nozzle
from its opening.
23. The machine of claim 14 wherein each of the multiplicity of the
fluidic oscillators is snap-fit into its respective one of the
openings.
24. The machine of claim 14 wherein each of the multiplicity of the
fluidic oscillators is held in its respective one of the openings
by a fastener.
25. The machine of claim 24 wherein each of the multiplicity of the
fluidic oscillator nozzles includes a mounting flange and a gasket
is positioned between the mounting flange and tubular member.
26. The machine of claim 1, further comprising: a ware rack within
the housing to locate the wares in the area.
27. The machine of claim 2 wherein each fluidic oscillator nozzle
includes at least one nozzle port guard adjacent its output
port.
28. The machine of claim 27 wherein each fluidic oscillator nozzle
includes a raised nozzle head surrounded by a mounting flange, with
a plurality of spaced apart support ribs extending from the
mounting flange to the raised nozzle head.
29. The machine of claim 1, further comprising: at least one of:
(i) a ware conveyor extending through the housing for carrying
wares through the housing, and (ii) a ware holding rack movable
between a position within the housing for cleaning wares and a
position exterior from the housing for loading and unloading
wares.
30. The machine of claim 1 wherein the nozzle is positioned in a
stationary arm within the housing.
31. The machine of claim 1 wherein the nozzle is positioned in a
moving arm within the housing.
32. The machine of claim 1 wherein the source of fluid is a source
of a liquid.
33. The machine of claim 32 wherein the liquid is one of a wash
liquid and a rinse liquid.
34. The machine of claim 1 wherein the source of fluid is a source
of a drying gas.
35. The machine of claim 1 wherein the source of fluid is a
steam.
36. The machine of claim 1 wherein the instantaneous direction of
the stream of fluid varies in an oscillatory manner.
37. The machine of claim 1 wherein the instantaneous direction of
the stream of fluid varies in three dimensions.
38. The ware wash machine of claim 1 wherein: at least one wash
liquid variable stream orientation nozzle is located within the
housing and arranged for outputting a stream of wash liquid that is
at least sometimes directed towards wares within the housing; and
at least one rinse liquid variable stream orientation nozzle is
located within the housing and arranged for outputting a stream of
rinse liquid that is at least sometimes directed towards wares
within the housing.
39. The machine of claim 38 wherein the at least one wash liquid
variable stream orientation nozzle is located in a mobile wash arm
within the housing and the at least one rinse liquid variable
stream orientation nozzle is located in a mobile rinse arm within
the housing.
40. The machine of claim 38 wherein the at least one wash liquid
variable stream orientation nozzle is located in a stationary wash
arm within the housing and the at least one rinse liquid variable
stream orientation nozzle is located in a stationary rinse arm
within the housing.
41. The machine of claim 1 wherein the nozzle axis passes through a
center of an output port of the variable stream orientation
nozzle.
42. A variable stream orientation nozzle, comprising: a first
nozzle side part; a second nozzle side part connected to the first
nozzle side part to form a functional variable stream orientation
nozzle; wherein the first nozzle side part and second nozzle side
part are identical in shape and configuration.
43. The nozzle of claim 42 wherein both the first nozzle side part
and second nozzle side part are of unitary construction.
44. The nozzle of claim 43 wherein both the first nozzle side part
and the second nozzle side part are of molded plastic
construction.
45. The nozzle of claim 44 wherein both the first nozzle side part
and the second nozzle side part are formed of a PVDF polymer.
46. The nozzle of claim 42 wherein both the first nozzle side part
and the second nozzle side part include internal sides having
identical protrusions and recesses, the first nozzle side part is
arranged in mirror image orientation relative to and adjacent the
second nozzle side part such that the protrusions of the first
nozzle side part frictionally engage into the recesses of the
second nozzle side part and the protrusions of the second nozzle
side part frictionally engage into the recesses of the first nozzle
side part.
47. The nozzle of claim 42 wherein both the first nozzle side part
and the second nozzle side part include at least one exterior
mating finger and at least one exterior mating opening, the first
nozzle side part is arranged in mirror image orientation relative
to and adjacent the second nozzle side part such that the exterior
mating finger of the first nozzle side part engages the exterior
mating opening of the second nozzle side part and the exterior
mating finger of the second nozzle side part engages the exterior
mating opening of the first nozzle side part.
48. The nozzle of claim 42 wherein the nozzle includes at least two
flexible fingers to facilitate snap-fit insertion of the nozzle
into an appropriately sized and shaped opening.
49. The nozzle of claim 42 wherein the nozzle includes at least two
fastener receiving bosses.
50. The nozzle of claim 42 wherein the first nozzle side part and
second nozzle side part are connected by one of an adhesive, one or
more fasteners, a welding operation or a brazing operation.
51. The nozzle of claim 42 wherein the nozzle comprises a fluidic
oscillator nozzle.
52. The nozzle of claim 42 wherein the nozzle includes a nozzle
outlet port and at least one nozzle port guard adjacent to the
nozzle port.
53. The nozzle of claim 42 wherein the second nozzle side part is
initially formed separate from the first nozzle side part prior to
being connected thereto to form the nozzle.
54. The nozzle of claim 42 wherein the first nozzle side part and
second nozzle side part are constructed together.
55. The nozzle of claim 54 wherein the first nozzle side part and
the second nozzle side part are initially constructed together in a
clam-shell configuration.
56. The nozzle of claim 55 wherein a hinge is provided between the
first nozzle side part and the second nozzle side part, the first
nozzle side part is folded adjacent the second nozzle side part to
form the functional variable stream orientation nozzle.
57. A fluid dispensing arm for a ware wash machine, the arm
including a plurality of variable stream orientation nozzles
positioned therein, the variable stream orientation nozzles being
of the type defined by claim 42.
58. A method for cleaning one or more wares such as dishes,
glasses, pots and pans, comprising the steps of: directing at least
one of a wash liquid, a rinse liquid, a sanitizing liquid, a drying
gas and a heating gas toward the ware through a variable stream
orientation nozzle.
59. The method of claim 58 wherein the variable stream orientation
nozzle is a fluidic oscillator nozzle.
60. The method of claim 58 wherein at least both wash liquid and
rinse liquid are directed toward the wares through respective
variable stream orientation nozzles.
61. The method of claim 58 wherein steam is directed toward the
wares through the variable stream orientation nozzle.
62. The method of claim wherein rinse liquid is directed toward the
wares through the variable stream orientation nozzle at a flow rate
of no more than about 0.3 gallons/min.
63. The method of claim 62 wherein the rinse liquid is output from
the variable stream orientation nozzle with an average drop size at
least twenty-five percent greater than that output by a fanjet
nozzle having the same flow rate.
64. The method of claim 63 wherein the variable stream orientation
nozzle is a fluidic oscillator nozzle.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. provisional
application Ser. No. 60/478,380, filed Jun. 3, 2003, the entirety
of which is incorporated herein by reference.
TECHNICAL FIELD
[0002] The present application relates generally to machines used
to wash kitchen wares such as dishes, glasses, utensils and pots
and pans, and more particularly to a ware wash machine that makes
effective use of one or more fluidic oscillator nozzles (or other
variable stream orientation nozzles as defined below) in one or
more areas of the machine.
BACKGROUND
[0003] It is known to provide varying types of ware wash machines.
Two of the most common types of commercial machines are the single
rack-type box unit and the conveyor-type unit. The former may
include a single chamber into which a rack of soiled ware can be
placed. Within the chamber, the entire cleaning process, typically
including washing, rinsing and drying is performed on the rack.
Multiple racks must be washed sequentially, with each rack being
completely cleaned before the next can be operated upon. A
conveyor-type machine, on the other hand, includes a conveyor for
carrying individual items or entire racks of ware through multiple
stations within the machine housing. A different operation may be
carried out at each station, such as washing, rinsing, or drying.
Thus, multiple items or racks of ware can be placed on the conveyor
and moved continuously through the machine so that, for example,
while one item or rack is being rinsed, a preceding item or rack
can be dried. One difficulty encountered in the construction of
such machines, regardless of type, is balancing effective washing
and rinsing with the goal of limiting the amount of liquid,
detergents, rinse agents and sanitizers used for such washing and
rinsing.
SUMMARY
[0004] In a ware wash machine one or more fluidic oscillator
nozzles or other variable stream orientation nozzles (defined
below) are used for outputting one or more of a rinse liquid, a
wash liquid, and a drying or heating gas such as air (heated or
unheated) or steam.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 is a perspective view of one embodiment of a
conveyor-type unit;
[0006] FIG. 2 is a side elevation of the unit of FIG. 1;
[0007] FIGS. 3 and 4 shows one embodiment of a rinse arm;
[0008] FIG. 5 depicts an oscillating output stream of a fluidic
oscillator nozzle;
[0009] FIG. 6-10 illustrate one embodiment of a fluidic oscillator
nozzle;
[0010] FIGS. 11-12 illustrate one embodiment of an undercounter
ware wash box-type unit; and
[0011] FIGS. 13-17 illustrate another embodiment of a fluidic
oscillator nozzle.
DETAILED DESCRIPTION
[0012] Referring to FIGS. 1 and 2, a conveyor-type unit 10 includes
a housing 12 with a conveyor 14 extending therethrough. The
conveyor 14 may be formed by spaced apart belts or a dog-type
system as described in U.S. Pat. No. 6,559,607. Other types of
conveyor systems could also be used, including conveyors pre-formed
with structures for receiving and supporting individual wares.
Whatever the construction of the conveyor, the region generally
above the conveyor represents a ware receiving area within the
housing 12.
[0013] The unit 10 includes an entry side 16 and an exit side 18. A
wash section 20 within the housing includes one or more wash arms
22 for directing wash liquid or other wash media onto wares
traveling along the conveyor 14. The wash liquid may be
recirculated by a suitable pump through a wash liquid tank 24
located beneath the wash section to receive the wash liquid as it
falls from the wares. The tank 24 may typically include an overflow
drain as well as a manual or automatic drain mechanism to enable
draining of the entire tank 24. In the illustrated embodiment the
wash arms 22 are located beneath the conveyor 14 to direct wash
liquid upward onto the wares. Other locations for the wash arms 22
are possible, including toward the top of the housing and on the
sides of the housing. A rinse section 26 located downstream of the
wash section 20 includes rinse arms 28 that direct rinse liquid
onto wares traveling along the conveyor 14. In the illustrated
embodiment, an upper rinse arm directs rinse liquid downward onto
the wares and a lower rinse arm directs rinse liquid upward onto
the wares. Other locations for the rinse arms are possible, such as
toward the sides of the housing.
[0014] Referring now to the exemplary rinse arm 28 shown in FIG. 3,
the arm includes a plurality of fluidic oscillator nozzles 30
positioned thereon for outputting respective streams of rinse
liquid. A fluidic oscillator nozzle is generally any nozzle that
outputs an oscillating stream of fluid, meaning that the direction
of the output stream of fluid varies in an oscillatory manner as
will be described in greater detail below. In the case of liquids,
the stream of liquid is typically made up of a series of drops of
the liquid being output. The resulting fan-shape 32 covered by the
sweep of the output stream of each nozzle is best seen in FIG. 4,
with the output stream 34 at a given moment in time reflected in
FIG. 5. Arrows A1-A5 reflect the instantaneous direction of
different points or drops (P1-P5) of the stream output by the port
at respectively different times, A1 representing instantaneous
direction for point or drop P1 of the stream output at an earliest
point in time, A2 representing instantaneous direction for point or
drop P2 output at a later time and so on. The illustrated arm 28
includes five nozzles 30, but the number could vary considerably.
In one example the lower rinse arm 28 includes six nozzles 30 and
the upper rinse arm includes five nozzles. The illustrated rinse
arm has an axis that extends substantially perpendicular to the
direction of the conveyor, but it is recognized that variations on
this orientation are possible.
[0015] In the illustrated embodiment, the rinse arm 28 in a
direction across a conveying direction (arrows 31 of FIG. 3 and
into or out of the page in FIG. 4) of the ware conveyor 14 and the
fluidic oscillator nozzles 30 are located to assure that rinse
liquid covers an entire lateral area of the conveyor. In
particular, where the rinse arm is a lower rinse arm, the
fan-shaped lateral coverage of the streams overlaps at a
location/height 36 that is just below the level of the conveyor 14.
Further, in the illustrated embodiment each of the plurality of
fluidic oscillator nozzles 30 is oriented to prevent its output
oscillating stream from interfering with oscillating streams output
by adjacent fluidic oscillator nozzles. In one example this result
is achieved by orienting each nozzle 30 to output its oscillating
stream such that oscillating movement of ejected liquid occurs at
an angle .theta. relative to a longitudinal axis 38 of the rinse
arm 28. In other words, the sweep of the nozzles is skewed to
prevent the interference while still assuring complete coverage
across the width of the conveyor. In one example, the angle .theta.
may be in the range of about two to ten degrees, but variations are
possible, including angles from zero to ninety degrees. Further, it
is recognized that constructions in which adjacent fluid streams
interfere with each other are possible.
[0016] Fanjet nozzles output water in a spread pattern, with drops
simultaneously output in multiple directions within the spread,
rather than outputting a stream of drops with changing
instantaneous direction as fluidic oscillator nozzles do. Fluidic
oscillator nozzles can provide an advantage of larger output drop
size (in the case of liquids) for a given flow rate than commonly
used fanjet nozzles having the same flow rate, providing better
washing or rinsing and also reducing heat loss to the air. In one
example, fluidic oscillators outputs rinse liquid with an average
drop size at least twenty-five percent greater than that output by
a typical fanjet nozzle having the same flow rate. It is
contemplated that the nozzles will typically be fed by a relatively
constant pressure fluid, but a pulsing output from the nozzles
could be produced, as by using a liquid manifold having an
associated variable pressure mechanism to vary the pressure within
the liquid manifold in a pulsed manner.
[0017] One embodiment of a fluidic oscillator nozzle 30 of the
rinse arm 28 is shown in FIGS. 6-10. The nozzle 30 includes a first
nozzle side part 50A, a second nozzle side part 50B constructed
separate from the first nozzle side part 50A and connected to the
first nozzle side part to form a functioning, complete fluidic
oscillator nozzle 30, wherein the first nozzle side part 50A and
second nozzle side part 50B are identical in shape and
configuration. Each nozzle side part may be of unitary, molded
plastic construction, with a Polyvinylidene Fluoride (PVDF)
homopolymer representing one acceptable material. It is also
recognized that other plastics could be used, or the nozzle could
be constructed of other materials including, by way of example,
metallic materials or ceramics. Further, rather than being molded,
other construction techniques for the nozzle side parts could be
used including, by way of example, machining, etching, forming and
EDM.
[0018] The nozzle side parts 50A and 50B have respective internal
sides 52A and 52B and respective external sides 54A and 54B. The
internal sides have identical protrusions (e.g., curved ridge 56,
curved ridge 58 and post 60) and identical recesses (e.g., curved
recess 62, curved recess 64 and post receiving aperture 66). In
final construction, the first nozzle side part 50 is arranged in
mirror image orientation relative to and adjacent the second nozzle
side part 52 such that the protrusions of the first nozzle side
part frictionally engage into the recesses of the second nozzle
side part and the protrusions of the second nozzle side part
frictionally engage into the recesses of the first nozzle side
part. Such engagement aids in holding the side parts together and
also performs a sealing function for the cavity formed internal of
the nozzle 30.
[0019] Both the first nozzle side part 50 and the second nozzle
side part 52 include at least one exterior mating finger (e.g.,
flexible fingers 70A, 70B and rigid fingers 72A, 72B) and at least
one exterior mating opening (e.g., fixed openings 74A, 74B and
movable openings 76A, 76B). In final construction the first nozzle
side part 50 is arranged in mirror image orientation relative to
and adjacent the second nozzle side part 52 such that the exterior
mating finger(s) of the first nozzle side part engage the exterior
mating opening(s) of the second nozzle side part and the exterior
mating finger(s) of the second nozzle side part engages the
exterior mating opening(s) of the first nozzle side part.
[0020] The nozzle may also include at least two flexible fingers
80A and 80B to facilitate snap-fit insertion of the nozzle into an
appropriately sized and shaped opening 29 of the rinse arm, such
fingers including respective surfaces 82A, 82B ramped to engage an
opening during insertion to flex the fingers to an insertion
position (e.g., inward toward the nozzle body), and the fingers
returning to a holding position (FIG. 10) after insertion. The
protruding part of the nozzle 30 includes a notch 85 to receive a
tool (such as a screwdriver) to enable removal of the nozzle from
the opening as by a prying operation. In one example, the
protruding part of the nozzle may protrude no more than about 0.4
inches in order to reduce the potential for nozzle breakage, but
variations on this distance are possible. In alternative
embodiments, the nozzle may include exterior threads to facilitated
engagement with the opening in the opening 29. In the case of metal
nozzles, they could be welded to the rinse arm or other manifold.
The use of fasteners is also contemplated.
[0021] While the foregoing nozzle description primarily
contemplates a nozzle in which the identical side parts are
snap-fit together, it is recognized that other connection
techniques could be used. For example, connection by one of an
adhesive, one or more fasteners, a welding operation, such as
ultrasonic welding for plastics, or a brazing operation (for
metals) might be used. Further, while the foregoing nozzle
description primarily contemplates first and second nozzle side
parts constructed separately, they could be constructed together
(e.g., as in a clamshell-type configuration including a connecting
hinge could be provided between a single molded plastic piece
including the two side parts, enabling the side parts to be folded
against each other and connected together, as by any suitable
technique previously mentioned, to form the internal cavity of the
nozzle). Still further, a one piece nozzle construction could also
be used. For example, an investment cast one-piece nozzle could be
used.
[0022] Referring again to FIG. 10, a description of the internal
cavity of the illustrated nozzle is provided. The nozzle includes
openings 86 on opposite sides (e.g., each side part is formed with
an opening that will lead to the internal cavity when the side
parts are connected). In particular, the openings lead to an
orifice 90. The size of the orifice 90 in combination with the
pressure of the fluid delivered thereto controls the flow rate of
the nozzle 30. The fluid stream exiting the orifice 90 is directed
towards a throat 92 that opens to a body portion 94 having an
associated exit port 96 through which the fluid stream is output
from the nozzle 30. A feedback loop 98 located adjacent the orifice
90 provides a changing pressure differential to vary the direction
of the output fluid stream in an oscillating manner. In particular,
the fluid stream output from the orifice 90 tends to attach to one
sidewall of the throat 92 and as a result of the "Coanda Effect"
follows that wall through the body portion 94. When the fluid
stream attaches to one sidewall it tends to create a low pressure
condition on the same side of the feedback loop 98 due to the high
speed flow near that side of the feedback loop 98. As a result,
fluid is drawn around the feedback loop toward the low pressure
region and toggles the fluid stream exiting the orifice 90 toward
the opposite sidewall of the throat 92. These conditions repeat and
the fluid stream exiting the orifice 90 repeatedly moves back and
forth attaching to the two opposed sidewalls and thus oscillating
its direction when output from the port 96 as best seen in FIG. 5.
The angular orientation or instantaneous direction of the output
stream with respect to an axis 201 of the nozzle varies over time.
In particular, in the illustrated embodiment the output stream
oscillates back and forth relative to a plane extending in and out
of the page in FIG. 10, where the illustrated nozzle axis 201 lies
in the plane. The two extremes of oscillation are represented at
202 and 204. For ease of reference the illustrated nozzle axis 201
is defined by a line passing though the center point of the nozzle
port 96 and the center point of the orifice 90. However, the
angular orientation or instantaneous direction of the output stream
can be said to vary relative to any nozzle axis defined by a line
passing through any two spaced apart points on the nozzle, where
the relative position between the two spaced apart points does not
change.
[0023] Varying degrees of oscillation can be achieved by modifying
the nozzle configuration. Oscillating frequency is also affected by
fluid pressure and medium (e.g., gas or liquid). Further, the shape
and orientation of the feedback loop provided within the nozzle
could vary significantly.
[0024] It is recognized that the foregoing nozzle construction is
one of many possible fluidic oscillator nozzle constructions that
could be used. Further, while the typical fluidic oscillator nozzle
construction provides an output stream that, more or less, moves
back and forth in two-dimensions along a plane, it is contemplated
that other fluidic oscillator nozzle constructions could be used
where the oscillation occurs in three dimensions. Further, it is
also recognized that nozzle constructions in which the output
stream technically does not "oscillate" are possible, such as an
output stream that moves in one direction to produce a helical or
cylindrical output, an expanding helical or cone-shaped output or
an output stream having an orientation that varies
randomly/chaotically relative to the axis of the nozzle. As used
herein the terminology "variable stream orientation nozzle" is
intended to encompass any and all such nozzle constructions that
output a stream of fluid with an instantaneous direction that
varies over time relative to a nozzle axis, regardless of whether
the variance is regular, random, oscillating or
non-oscillating.
[0025] The wash arms 22 could also include fluidic oscillator
nozzles or other variable stream orientation nozzles positioned
therein to direct wash fluid onto the wares. It is generally
contemplated that the wash arm nozzles would be constructed to
produce a higher flow rate than the rinse arm nozzles, but
variations are possible, including the use of identical nozzles for
both rinse and wash.
[0026] While the foregoing embodiment of the conveyor-type ware
wash machine contemplates a single wash section 20 and a single
rinse section 26, it is recognized that conveyor-type machines
having multiple wash sections and/or multiple rinse sections could
be provided. It is further contemplated that other sections could
be provided within the machine, such as an upstream pre-wash
section using one or more variable stream orientation nozzles to
output a pre-wash liquid to remove larger food materials from wares
or to output steam, a downstream sanitizing section using one or
more variable stream orientation nozzles to output a sanitizing
liquid, a downstream drying section using one or more variable
stream orientation nozzles to output air (heated or unheated) or
some other gas for drying, or a downstream heating section in which
heated air or steam is output by one or more variable stream
orientation nozzles to heat the wares for sanitizing purposes.
[0027] Moreover, use of fluidic oscillator nozzles in undercounter
and other box units is also contemplated. For example, referring to
FIGS. 11 and 12, an exemplary undercounter unit is shown and
includes a washing/rinsing chamber 100 that is defined by a
cabinet, housing usually formed of stainless steel panels and
components, and including a top wall 110, side walls 120 and rear
wall 140, and a front facing door 150, hinged at its lower end, as
indicated at 160. The chamber 100 is vented to ambient pressure
through labyrinth seals (not shown) near the top wall. The cabinet
is supported upon legs 170 which provide the clearance for the
underside of the machine to permit cleaning beneath it as may be
required by various-local sanitation codes. At the bottom of the
chamber, as part of the sloping bottom wall 200 of the cabinet, is
a relatively small sump 220 that may have a removable strainer
cover 230.
[0028] Above the bottom wall, rails 240 provide support for
standard ware racks 250, loaded with ware to be washed and
sanitized, which are loaded and unloaded through the front door.
The rack 250 may be a rolling rack intended to remain with the unit
or may be a mobile rack intended to be removed entirely when the
wares are removed. A coaxial fitting 270 is supported on the lower
wall 200, centrally of the chamber, and this fitting in turn
provides support for a lower wash arm 300 and lower rinse arm 320,
each being rotational as is common. An upper wash arm 340 and upper
rinse spray heads 360 are supported from the top wall of the
chamber. The wash arms 300 and 340 may include suitable fluidic
oscillator nozzles 302 (or other variable stream orientation
nozzles) incorporated therein (e.g., as in the manner previously
described with respect to FIG. 9 or any other suitable manner).
Likewise rinse arm 320 may include suitable fluidic oscillator
nozzles 322 (or other variable stream orientation nozzles), and the
spray heads 360 may include suitable fluidic oscillator nozzles (or
other variable stream orientation nozzles).
[0029] The fresh hot rinse water supply line 400 extends from a
source of hot water and is connected to the rinse arm 320 and rinse
spray heads 360. The wash water supply line 420 is connected to the
upper and lower wash arms 340 and 300, and receives wash water from
a pump 450 mounted to one side of and exterior of the cabinet. The
pump in turn is supplied from an outlet pipe 470 that extends from
sump 220 and returns or recirculates the wash water sprayed over
the ware in the rack during the wash segment of the machine cycle.
Thus, during the wash portion of an operating cycle, pump 450
functions as a recirculating pump means.
[0030] A solenoid operated drain valve 480 is connected by a branch
or drain pipe 490 to the wash water supply line 420 immediately
downstream of the outlet of pump 450, and this valve when open
allows flow of the pump discharge to a drain line 500 that may be
connected into a suitable kitchen drain system 520, according to
the applicable code regulations. In many kitchens in newer fast
food restaurants the drain system may be considerably above the
floor, thus the pumped discharge from the dishwasher is a desired
feature in those installations. Also, when the drain valve is open,
the path of least resistance to the pump output is through drain
valve 480, and flow through the recirculating wash plumbing quickly
diminishes due to back pressure created at the nozzles of the wash
arms. At this time the pump 450 functions as a drain pump means.
During the normal cycle of operations of this machine, drain valve
480 is opened once each cycle of operation, after the wash segment
and before the rinse segment of the cycle.
[0031] A solenoid-operated fill valve 550 is connected, in the
embodiment shown, to control the supply of fresh water to a booster
heater tank 580, which is a displacement type heater tank having
its inlet connected to receive water through fill valve 550, and
its outlet connected to the fresh rinse water supply line 400. The
booster heater has a heating element 700 and has the usual pressure
relief valve 590 which will divert hot water through an overflow
pipe in the event the tank pressure exceeds a predetermined value.
While the illustrated booster heater tank 580 and pump 450 are
shown alongside the main dishwasher housing, it is recognized that
embodiments in which the pump 450 and booster are provided internal
to the main housing, such as beneath the wash chamber, are within
the contemplated scope of the various inventions described
herein.
[0032] Also, a low capacity (e.g. 500 W) heater 720 may be located
in or on the sump 220. Such a heater may be, for example, a wire or
similar heating strip embodied in an elastomeric pad that can be
adhered to the exterior of the sump to heat water in the machine by
conduction, if necessary. The heater 720 may alternatively be
provided internally.
[0033] The undercounter unit of FIGS. 11 and 12 could also
incorporate one or more variable stream orientation nozzles that
output a gaseous fluid, such as air (heated or unheated) or steam,
and it is recognized that numerous variations on undercounter units
or other box units are possible.
[0034] Referring now to FIGS. 13-17, an alternative embodiment of a
fluidic oscillator nozzle and its installation in a rinse or wash
arm is shown. FIGS. 13 and 14 represent identical nozzle halves 800
oriented on the page in a manner that permits them to be fitted
together to form a functional nozzle. The internal side of each
nozzle half 800 includes protrusions (e.g., curved protrusions 802,
804 and 806, and posts 808 and 810) that mate with corresponding
recesses (e.g., curved recesses 812, 814 and 816 and cylindrical
openings 818 and 820) on the other nozzle half in a friction fit
manner to aid in holding the two nozzle halves together in
assembled form. An ultrasonic welding process, solvent welding
process or heat and pressure welding process may also be used to
more permanently connect the nozzle halves together. Screws or
other fasteners could also be used in addition to or in place of
the welding and/or friction fit. Each nozzle half 800 also includes
a boss 822, which can be used for connecting the nozzle in a wash
or rinse arm as described in further detail below. Notably, the
orifice, throat, body portion, output port and feedback loop of the
nozzle created by combined nozzle halves 800 are all primarily
defined by the curved protrusions 802, 804 and 806.
[0035] As shown in FIG. 15, nozzle halves 800 combine to form a
functional nozzle 824. A gasket/seal 826 may be provided for
location against surface 828 of the nozzle, with gasket housing 830
provided to limit the outward movement of the gasket 826.
Protrusions 832 of the nozzle 824 are sized for frictionally
fitting in recesses 834 of the gasket housing 830 to hold the
components together in the nozzle assembly form 836 shown in FIG.
16.
[0036] Nozzle assembly 836 is shown mounted in exemplary wash or
rinse arm 840 in FIG. 17, with portion 842 of the assembly
protruding from the arm 840 and with portion 844 internal to the
arm 840. A screw 846 is positioned through an opening in the bottom
of the arm and threaded into boss 822 to secure the nozzle assembly
836, with the screw tightened sufficiently to cause the gasket 826
to form a seal against the top of the arm 840. Fluid under pressure
within the arm 840 flows into inlet opening 848 of the nozzle and
is ejected from exit port or orifice 850 in an oscillating manner
as previously described. Notably, exit port 850 is located near the
top of an upwardly projecting nozzle head 852 of the nozzle
assembly, where nozzle head 852 is surrounded by a mounting flange
854 having an underside adjacent the top surface of arm 840. Ribs
856, which may be molded with the nozzle, are disposed at multiple
locations around the nozzle head 852 and provide increased
stiffness to aid in keeping the nozzle head from breaking or
bending if impacted by wares or anything else within the ware wash
machine. The ribs can also aid in keeping the nozzle part flat
during molding and when the nozzle halves 800 are welded together.
Nozzle port guards 858, illustrated in the form of projecting
bumps, are disposed on opposite sides of the nozzle port 850. The
port guards 858 project above the nozzle port 850 so that the port
guards 858 are in position to be impacted before the nozzle port
850. In the event the arm 840 is removed from a warewash machine
for cleaning, it is possible that the arm 840 could be subjected to
impacts, such as an operator banging the arm against a sink or
other structure. In such cases the nozzle guards 858 should take
the brunt of any impact instead of the nozzle port 850, thereby
preventing or limiting damage/deformation of the nozzle port 850,
which could adversely affect the spray pattern of the nozzle.
[0037] It is to be clearly understood that the above description is
intended by way of illustration and example only and is not
intended to be taken by way of limitation. For example, while the
nozzles are primarily described in association with manifolds in
the form of stationary or rotating wash arms and/or rinse arms, it
is recognized that other manifold types could be used, such as an
oscillating arm or the wall of a wash chamber housing where the
area behind the wall constitutes a manifold and nozzles are fixed
in openings of the wall. Further, a manifold is not required, as
each nozzle could be supplied with its fluid (liquid or gas) by an
individual line not associated with any manifold. While it is
contemplated that the delivery of any one fluid (e.g., any one of a
rinse liquid, wash liquid or drying gas) will most often utilize
multiple nozzles, it is possible that a machine could use a single
nozzle to deliver a given fluid, or that the same nozzle or nozzles
could be used to deliver multiple different fluids during different
stages of a ware wash operation. Further, while the primary
embodiments and examples described above contemplate nozzles that
are fixed relative to some type of manifold, it is recognized that
the nozzles could move relative to the structure to which they are
mounted. Further, the terms "rinse liquid" and "wash liquid" are to
be construed broadly, as each could be comprised of heated or
unheated water, any heated or unheated water solution (e.g., water
plus detergent as a wash liquid or water plus a rinse agent
or/sanitizing agent as a rinse liquid), or in some cases
non-aqueous liquids. Other changes and modifications could be
made.
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