U.S. patent application number 12/784864 was filed with the patent office on 2011-06-02 for radial jet air impingement nozzle, oven and method.
This patent application is currently assigned to Merrychef Limited. Invention is credited to Martin Behle, Douglas S. Jones.
Application Number | 20110126818 12/784864 |
Document ID | / |
Family ID | 43126533 |
Filed Date | 2011-06-02 |
United States Patent
Application |
20110126818 |
Kind Code |
A1 |
Behle; Martin ; et
al. |
June 2, 2011 |
RADIAL JET AIR IMPINGEMENT NOZZLE, OVEN AND METHOD
Abstract
An oven that generates impingement air with a jet nozzle that
includes a nozzle insert that provides a slot-shaped orifice
through which the air flows toward a product to be heated or
cooled. In particular, an oven for cooking a food product is
disclosed in which a plurality of the jet nozzles produces an
overall turbulence and a homogeneous heat transfer at a surface of
the food product.
Inventors: |
Behle; Martin; (Remscheid,
DE) ; Jones; Douglas S.; (New Port Richey,
FL) |
Assignee: |
Merrychef Limited
|
Family ID: |
43126533 |
Appl. No.: |
12/784864 |
Filed: |
May 21, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61180575 |
May 22, 2009 |
|
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|
Current U.S.
Class: |
126/21A ;
222/566 |
Current CPC
Class: |
A21B 1/245 20130101 |
Class at
Publication: |
126/21.A ;
222/566 |
International
Class: |
F24C 15/32 20060101
F24C015/32 |
Claims
1. An oven comprising: an oven chamber and a blower that is
disposed to circulate air through said oven chamber; an air
impingement plate that is disposed in said circulating air and that
is located to provide impingement air toward a product in said oven
chamber, and at least one jet nozzle that is disposed in said
impingement plate and a nozzle insert disposed in relation to said
jet nozzle to form about said nozzle insert a slot-shaped orifice
through which said impingement air flows.
2. The oven of claim 1, wherein a shape of said slot-shaped orifice
is selected from the group consisting of: curvilinear, ring,
annular, polygonal, square, rectangular, elliptical, multi-point,
jack and cruciform.
3. The oven of claim 1, wherein a shape of said nozzle insert is
selected from the group consisting of: bell, goblet, cone,
margarita glass, upside down filled wine glass, pedestal, maraca,
mirrored pedestal, and filled wide bell.
4. The oven of claim 1, wherein said slot-shaped orifice has a
thickness that produces an overall flow pattern at the surface of
said product that enhances heat transfer to said product and a
homogeneous heat transfer at a surface of said product.
5. The oven of claim 1, wherein said nozzle insert is selected from
the group consisting of: solid and hollow.
6. The oven of claim 1, wherein a shape of said jet nozzle is
selected from the group consisting of: a match with a shape of said
nozzle insert and a non-match of a shape of said nozzle insert.
7. The oven of claim 1, wherein said jet nozzle is one of a
plurality of jet nozzles that each have an associated nozzle insert
in relation to said jet nozzle to form about said nozzle insert a
slot-shaped orifice through which said impingement air flows, and
wherein said plurality of jet nozzles collectively provide a
homogeneous and high heat transfer distribution at said
product.
8. The oven of claim 1, wherein a temperature of said air is
controlled by a unit selected from the group consisting of: heating
and cooling.
9. The oven of claim 1, further comprising a fastener that fastens
said nozzle insert to said impingement plate to vary an axial
position of said nozzle insert relative to said impingement
plate.
10. The oven of claim 1, further comprising a heater disposed to
heat said circulating air, and wherein said product is a food
product.
11. A method of operating an oven comprising: circulating air in an
oven chamber; providing an impingement plate in said circulating
air to provide impingement air toward a product in said oven
chamber; and shaping said impingement air with a slot-shaped
orifice through which said impingement air flows.
12. The method of claim 11, wherein a shape of said slot-shaped
orifice is selected from the group consisting of: curvilinear,
ring, annular, polygonal, square, rectangular, elliptical,
multi-point, jack and cruciform.
13. The method of claim 11, wherein a temperature of said air is
controlled by a unit selected from the group consisting of: heating
and cooling.
14. The method of claim 11, further comprising a heater disposed to
heat said circulating air, and wherein said product is a food
product.
15. The method of claim 11, wherein at least one jet nozzle is
disposed in said impingement plate and a nozzle insert is disposed
in relation to said jet nozzle to form about said nozzle insert
said slot-shaped orifice through which said impingement air
flows.
16. The method of claim 15, wherein a shape of said nozzle insert
is selected from the group consisting of: bell, goblet, cone,
margarita glass, upside down filled wine glass, pedestal, maraca,
mirrored pedestal, and filled wide bell.
17. The method of claim 15, wherein said slot-shaped orifice has a
thickness that produces an overall flow pattern at the surface of
said product that enhances heat transfer to said product and a
homogeneous heat transfer at a surface of said product.
18. The method of claim 15, wherein said insert is selected from
the group consisting of: solid and hollow.
19. The method of claim 15, wherein a shape of said jet nozzle is
selected from the group consisting of: a match with a shape of said
nozzle insert and a non-match of a shape of said nozzle insert.
20. The method of claim 15, wherein said jet nozzle is one of a
plurality of jet nozzles that each have an associated nozzle insert
in relation to said jet nozzle to form about said nozzle insert a
slot-shaped orifice through which said impingement air flows, and
wherein said plurality of jet nozzles collectively provide a
homogeneous and high heat transfer distribution at said
product.
21. The method of claim 15, further comprising a fastener that
fastens said nozzle insert to said impingement plate to vary an
axial position of said nozzle insert relative to said impingement
plate.
22. A jet nozzle that is disposed in an air impingement plate and
at least one nozzle insert disposed in relation to said jet nozzle
to form about said nozzle insert a slot-shaped orifice through
which impingement air flows.
23. The jet nozzle of claim 22, wherein a shape of said slot-shaped
orifice is selected from the group consisting of: curvilinear,
ring, annular, polygonal, square, rectangular, elliptical,
multi-point, jack and cruciform.
24. The jet nozzle of claim 23, wherein a shape of said nozzle
insert is selected from the group consisting of: bell, goblet,
cone, margarita glass, upside down filled wine glass, pedestal,
maraca, mirrored pedestal, and filled wide bell.
25. The jet nozzle of claim 24, wherein a shape of said jet nozzle
is selected from the group consisting of: a match with a shape of
said nozzle insert and a non-match of a shape of said nozzle
insert.
26. The jet nozzle of claim 22, wherein said nozzle insert is
selected from the group consisting of: solid and hollow.
27. The jet nozzle of claim 22, further comprising a fastener that
fastens said nozzle insert to said impingement plate to vary an
axial position of said nozzle insert relative to said impingement
plate.
Description
RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/180,575, filed on May 22, 2009, the entire
contents of which are incorporated herein.
FIELD OF THE INVENTION
[0002] This disclosure relates to new and improved air impingement
nozzles, methods and ovens that use the nozzles for heating or
cooling a product within the air streams coming out of the air
impingement nozzles. For example, the improved impingement nozzles
can be used in an oven for cooking food products.
BACKGROUND OF THE DISCLOSURE
[0003] Jet nozzles are used to provide impingement air to heat or
cool a product in a variety of ovens, including countertop ovens,
conveyor ovens, and the like. Several known jet nozzles are shown
in U.S. Pat. No. 6,817,283, which discloses an oven for cooking
food products. In some applications, the jet nozzles are shaped and
spaced to provide non-overlapping columns of hot impingement air
that impinge directly on the surface of the food product. A
disadvantage of these nozzles is that the columns of hot
impingement air develop hot spots that result in a pattern of
overcooked and undercooked areas of the food product. In other
applications, the jet nozzles are shaped and spaced to provide a
plume or blanket of hot air at the surface of the food product.
[0004] There is a need for an improved jet nozzle.
[0005] There is also a need for a method and an oven with the
improved jet nozzles.
SUMMARY OF THE DISCLOSURE
[0006] The present disclosure describes a jet nozzle that provides
hot air acceleration and a nozzle insert or member in the flow path
beneath the jet nozzle that transforms the air flow to create a
relatively thin thermal boundary layer of hot air at the surface of
the food, utensil or any other material placed within the air
stream that is characterized by an overall flow pattern at the
surface of the food product that enhances the heat transfer to the
product. In a preferred embodiment, the member has a cone like or
goblet like shape that causes the airflow to form a relatively thin
bell-shaped flow ring after separating from the nozzle insert,
which leads to a more homogeneous and high heat distribution
cooking of food products.
[0007] One embodiment of an oven of the present disclosure
comprises an oven chamber and a blower that is disposed to
circulate air through the oven chamber. An air impingement plate is
disposed in the circulating air and is located to provide
impingement air toward a product in the oven chamber. At least one
jet nozzle is disposed in the impingement plate. A nozzle insert is
disposed in relation to the jet nozzle to form about the nozzle
insert a slot-shaped orifice through which the impingement air
flows.
[0008] In another embodiment of the oven of the present disclosure,
a shape of the slot-shaped orifice is selected from the group
consisting of: curvilinear, ring, annular, polygonal, square,
rectangular, elliptical, multi-point, jack and cruciform.
[0009] In another embodiment of the oven of the present disclosure,
a shape of the nozzle insert is selected from the group consisting
of: bell, goblet, cone, margarita glass, upside down filled wine
glass, pedestal, maraca, mirrored pedestal, and filled wide
bell.
[0010] In another embodiment of the oven of the present disclosure,
the slot-shaped orifice has a thickness that produces an overall
flow pattern at the surface of the product that enhances heat
transfer to the product and a homogeneous heat transfer at a
surface of the product.
[0011] In another embodiment of the oven of the present disclosure,
the nozzle insert is selected from the group consisting of: solid
and hollow.
[0012] In another embodiment of the oven of the present disclosure,
a shape of the jet nozzle is selected from the group consisting of:
a match with a shape of the nozzle insert and a non-match of a
shape of the nozzle insert.
[0013] In another embodiment of the oven of the present disclosure,
the jet nozzle is one of a plurality of jet nozzles that each have
an associated nozzle insert in relation to the jet nozzle to form
about the nozzle insert a slot-shaped orifice through which the
impingement air flows. The plurality of jet nozzles collectively
provide a homogeneous and high heat transfer distribution at the
product.
[0014] In another embodiment of the oven of the present disclosure,
a temperature of the air is controlled by a unit selected from the
group consisting of: heating and cooling.
[0015] In another embodiment of the oven of the present disclosure,
a fastener fastens the nozzle insert to the impingement plate to
vary an axial position of the nozzle insert relative to the
impingement plate.
[0016] In another embodiment of the oven of the present disclosure,
a heater is disposed to heat the circulating air, and wherein the
product is a food product.
[0017] In one embodiment of the method of the present disclosure,
the oven is operated by steps comprising:
[0018] circulating air in an oven chamber;
[0019] providing an impingement plate in the circulating air to
provide impingement air toward a product in the oven chamber;
and
[0020] shaping the impingement air with a slot-shaped orifice
through which the impingement air flows.
[0021] In another embodiment of the method of the present
disclosure, a shape of the slot-shaped orifice is selected from the
group consisting of: curvilinear, ring, annular, polygonal, square,
rectangular, elliptical, multi-point, jack and cruciform.
[0022] In another embodiment of the method of the present
disclosure, a temperature of the air is controlled by a unit
selected from the group consisting of: heating and cooling.
[0023] In another embodiment of the method of the present
disclosure, a heater is disposed to heat the circulating air, and
the product is a food product.
[0024] In another embodiment of the method of the present
disclosure, at least one jet nozzle is disposed in the impingement
plate. A nozzle insert is disposed in relation to the jet nozzle to
form about the nozzle insert the slot-shaped orifice through which
the impingement air flows.
[0025] In another embodiment of the method of the present
disclosure, a shape of the nozzle insert is selected from the group
consisting of: bell, goblet, cone, margarita glass, upside down
filled wine glass, pedestal, maraca, mirrored pedestal, and filled
wide bell.
[0026] In another embodiment of the method of the present
disclosure, the slot-shaped orifice has a thickness that produces
an overall flow pattern at the surface of the product that enhances
heat transfer to the product and a homogeneous heat transfer at a
surface of the product.
[0027] In another embodiment of the method of the present
disclosure, the insert is selected from the group consisting of:
solid and hollow.
[0028] In another embodiment of the method of the present
disclosure, a shape of the jet nozzle is selected from the group
consisting of: a match with a shape of the nozzle insert and a
non-match of a shape of the nozzle insert.
[0029] In another embodiment of the method of the present
disclosure, the jet nozzle is one of a plurality of jet nozzles
that each have an associated nozzle insert in relation to the jet
nozzle to form about the nozzle insert a slot-shaped orifice
through which the impingement air flows. The plurality of jet
nozzles collectively provides a homogeneous and high heat transfer
distribution at the product.
[0030] In another embodiment of the method of the present
disclosure, a fastener fastens the nozzle insert to the impingement
plate to vary an axial position of the nozzle insert relative to
the impingement plate.
[0031] In one embodiment of the jet nozzle of the present
disclosure, a jet nozzle is disposed in an air impingement plate
and at least one nozzle insert is disposed in relation to the jet
nozzle to form about the nozzle insert a slot-shaped orifice
through which impingement air flows.
[0032] In another embodiment of the jet nozzle of the present
disclosure, a shape of the slot-shaped orifice is selected from the
group consisting of:
[0033] curvilinear, ring, annular, polygonal, square, rectangular,
elliptical, multi-point, jack and cruciform.
[0034] In another embodiment of the jet nozzle of the present
disclosure, a shape of the nozzle insert is selected from the group
consisting of: bell, goblet, cone, margarita glass, upside down
filled wine glass, pedestal, maraca, mirrored pedestal, and filled
wide bell.
[0035] In another embodiment of the jet nozzle of the present
disclosure, a shape of the jet nozzle is selected from the group
consisting of: a match with a shape of the nozzle insert and a
non-match of a shape of the nozzle insert.
[0036] In another embodiment of the jet nozzle of the present
disclosure, the nozzle insert is selected from the group consisting
of: solid and hollow.
[0037] In another embodiment of the jet nozzle of the present
disclosure, a fastener fastens the nozzle insert to the impingement
plate to vary an axial position of the nozzle insert relative to
the impingement plate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Other and further objects, advantages and features of the
present invention will be understood by reference to the following
specification in conjunction with the accompanying drawings, in
which like reference characters denote like elements of structure
and:
[0039] FIG. 1 is a perspective view of the oven of the present
disclosure;
[0040] FIG. 2 is a cross-sectional view along line 2 of the oven of
FIG. 1;
[0041] FIG. 3 is a block diagram of the electrical control of the
oven of FIG. 1;
[0042] FIG. 4 is a perspective view of the jet plate of the oven of
FIG. 1;
[0043] FIG. 5 is a profile view of a nozzle with nozzle insert of
the jet plate of FIG. 3;
[0044] FIG. 6 is a perspective view of the nozzle of FIG. 5
attached to a section of the jet plate of FIG. 4; and
[0045] FIGS. 7-12 are perspective views of alternate embodiments of
the nozzle insert for the jet plate of FIG. 4.
DESCRIPTION OF THE PREFERRED EMBODIMENT
[0046] It is contemplated that the jet nozzles of the present
disclosure can be used in any type of oven that uses impingement
air. By way of example and completeness of description, the nozzles
are described herein for use with a countertop oven.
[0047] Referring to FIGS. 1 and 2, an oven 30 of the present
disclosure comprises a pair of side walls 32 and 34, a back wall
36, a top wall 38, a bottom wall 40 and a front wall 42. Front wall
42 comprises a door 44 and a control panel 50 (shown in FIG. 3),
which, for example, may be located above, below or beside door 44.
A handle (not shown) is disposed on door 42 for opening the door in
a pull down manner or a side rotatable manner.
[0048] Oven 30 comprises an oven chamber 70 defined by side walls
32 and 34, back wall 36, bottom wall 40 and a jet plate 72. Jet
plate 72 is disposed below top wall 38. Oven 30 further comprises a
fan box 74 defined by side walls 32 and 34, back wall 36, top wall
38 and a wall 76. A fan 80 is disposed in fan box 74 and a heater
52 (shown in FIG. 3) is disposed on the high pressure side of fan
80. In alternate embodiments, heater 52 may be located on the
suction side of fan 80. For example, heater 52 may be located in
front of an opening 86 in back wall 36 that is at least partly in
alignment with fan 80. Fan 80 may be any fan suitable for
circulating air in an oven. A fan motor 82 is axially connected to
drive fan 80. Fan motor 82 may be a single speed or a variable
speed motor that rotates in a single direction or in both
directions. In one embodiment, fan motor 82 is a three phase cage
induction motor suitable for inverter drive, preferably L7FWDS-638
manufactured by Hanning. Heater 52 may be any heater (gas,
induction, microwave, electric and the like) suitable for heating
circulating air in a convection and/or impingement air oven.
Preferably, heater 52 is an electrical heater having one or more
heating elements disposed in a peripheral location of the blades of
fan 80.
[0049] An oven rack 84 is supported within oven chamber 70 by any
suitable means that allows for proper location in oven chamber 70
(e.g., mounted to side walls 32 and 34, bottom wall 40, back wall
36, front wall 42, door 44 and the like). Oven rack 84 may be a
standard food rack, i.e., available off-shelf. In an alternate
embodiment a plurality of oven racks 84 may be disposed in oven
chamber 70.
[0050] Referring to FIGS. 1, 2 and 4, back wall 36 comprises a
plurality of openings to provide a path for air to circulate
between oven chamber 70 and fan box 74. Opening 86 is located above
the bottom of back wall 36. A grease filter (not shown) may be
mounted to back wall 36 to cover opening 86, which is preferably at
least partially in registration with fan 80. An opening 88 is
located at or near the top of back wall 36.
[0051] A catalyst structure (not shown) may be disposed in fan box
74 between fan 80 and back wall 36. For example, the catalyst may
be disposed adjacent back wall 36 in at least partial registration
with opening 88 of back wall 36 and fan 80. Opening 86 may be
configured to block microwave energy penetration in microwave
embodiments. In an alternate embodiment, the catalyst structure may
be located in front of opening 86.
[0052] Referring to FIG. 3, a controller 54 is connected in circuit
with control panel 50, fan motor 82, heater 52 and a temperature
sensor 56. Controller 54 is operative in response to operator
commands entered via control panel 50 to control fan motor 82 to
drive fan 80 to circulate air from the high pressure side of fan 80
in a path that includes fan box 74, opening 88, jet plate 72 oven
chamber 70 and opening 86 to the low pressure side of fan 80 as
shown by the arrows in FIG. 2. Temperature sensor 56 may be
disposed in oven chamber 70 to sense the oven chamber temperature.
Controller 54 is also operative in response to operator commands
entered via control panel 50 and to temperature sensor 56 to
control heater 52 to heat the circulating air to a desired
temperature.
[0053] Referring to FIGS. 1, 2, 4 and 5, jet plate 72 comprises a
plurality of jet nozzles 100 arranged in staggered rows and
columns. It is contemplated that other patterns and shapes of jet
nozzles 100 and insert 102 may be used. Jet nozzles 100 are shaped
to provide high velocity shapes of hot or cold impingement air
toward oven rack 84. Disposed in each jet nozzle 100 is a nozzle
insert 102 that is shaped to provide a predetermined air flow
pattern 104. Nozzle insert 102 preferably has a shape that
generates a bell shaped flow pattern, which is relatively thin or
has a thickness so as to generate overall flow pattern at the
surface of the food product that enhances the heat transfer to the
product. In consequence, the heat transfer pattern is more
homogeneous at the food product and/or bottom wall 40. This leads
to a more homogeneous and high heat transfer distribution, which
leads to accelerated but homogeneous cooking of food products in
oven 30 as well as other types of ovens (e.g., conveyor ovens,
industrial ovens, laboratory ovens, residential ovens and the like)
where guided hot or cold airflow is used for convection heating and
cooling. Nozzle insert 102 is preferably cone shaped to produce the
bell-shaped airflow pattern 104. Nozzle insert 102 may be either
solid or hollow. Nozzle insert 102 is disposed within jet nozzle
100 to form about nozzle insert 102 a slot-shaped orifice 126
through which the impingement air flows.
[0054] Compared to traditional jet nozzles, the bell shaped flow
pattern is a function of the "contact" surface between the fluid or
air in motion and the air not in motion and is much greater.
Therefore, shear stresses show stronger effects, which means that
vortices occur and the point of transition from laminar air to
turbulent air moves further up-stream. towards the nozzle which
results in a stronger turbulence level down-stream of the jet
nozzle toward the food product. The nozzle insert of the present
disclosure advantageously leads to wider nozzle spacing and reduced
distance between impingement plate 72 and the surface of the food
product to achieve a more homogeneous air flow pattern. In some
embodiments, the jet nozzles and jet inserts can be larger so that
fewer are needed, which may allow the space between jet plate 72
and the food product to be greater. The present disclosure
contemplates that many embodiments are possible based on the size
and shape of jet nozzle 100 and nozzle insert 102 and spacing may
be increased as well.
[0055] Referring to FIG. 6, a portion of jet plate 72 is shown with
a bracket assembly 110 for attaching nozzle insert 102 to jet plate
72. Bracket assembly 110 comprises a bridge like structure
comprising base portions 112 and 114 that are connected to ramp
sections 116 and 118, respectively, which are connected to a top
portion 120. Base portions 112 and 114 are attached to a top side
of jet plate 72 by any suitable fastener, such as a weld, an
adhesive, screw, bolt and the like. A stem 122 is attached at one
end to nozzle insert 102 and at a distal end to top portion 120 of
bracket assembly 110 by a bolt 122 or other fastener, such as a
weld, adhesive and the like. In one embodiment, stem 122 and nozzle
insert 102 are formed as an integral or unitary part. In one
embodiment, the distal end may carry screw threads that screw into
mating screw threads in a properly aligned hole in top portion 120,
thereby allowing for vertical adjustment of nozzle insert 102 to
vary the vertical position of nozzle insert 102 with respect to jet
nozzle 100. Nozzle 100 reduces pressure losses at the leading edge
and guides the airflow smoothly.
[0056] The present disclosure contemplates that the nozzle insert
may have different shapes to provide different airflow patterns
such as those shown in FIGS. 7-12. Nozzle insert 130 in FIG. 7 has
filled margarita glass shape. Nozzle insert 140 in FIG. 8 has an
upside down filled wine glass shape. Nozzle insert 150 in FIG. 9
has a pedestal shape. Nozzle insert 160 in FIG. 10 has a Maraca
shape. Nozzle insert 170 in FIG. 11 has a mirrored pedestal shape.
Nozzle insert 180 in FIG. 12 has a filled wide bell shape. These
are examples of nozzle and insert shapes and this disclosure is not
limited to circular and conical shapes.
[0057] A shape of the slot-shaped orifice is selected from the
group consisting of: curvilinear, ring, annular, polygonal, square,
rectangular, elliptical, multi-point, jack and cruciform.
[0058] A shape of the nozzle insert is selected from the group
consisting of: bell, goblet, cone, margarita glass, upside down
filled wine glass, pedestal, maraca, mirrored pedestal, and filled
wide bell.
[0059] It is contemplated that the convective airflow of the
present disclosure may also be used in cooling applications as well
as in heating applications. The present disclosure having been thus
described with particular reference to the preferred forms thereof,
it will be obvious that various changes and modifications may be
made therein without departing from the spirit and scope of the
present disclosure and appended claims.
* * * * *