U.S. patent application number 13/437153 was filed with the patent office on 2013-10-03 for hybrid gas surface burner.
The applicant listed for this patent is Paul Bryan Cadima, Bai Han. Invention is credited to Paul Bryan Cadima, Bai Han.
Application Number | 20130255663 13/437153 |
Document ID | / |
Family ID | 49233197 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130255663 |
Kind Code |
A1 |
Cadima; Paul Bryan ; et
al. |
October 3, 2013 |
HYBRID GAS SURFACE BURNER
Abstract
A gas burner assembly is provided for a cooking appliance. The
gas burner assembly comprises an outer gas burner configured to
provide an outer cooking flame; and an inner infrared burner
configured to provide an inner cooking flame. A gas cooking
appliance is also provided that comprises a cooktop surface; and a
gas burner assembly that comprises an outer gas burner configured
to provide an outer cooking flame; and an inner infrared burner
configured to provide an inner cooking flame.
Inventors: |
Cadima; Paul Bryan;
(Prospect, KY) ; Han; Bai; (Louisville,
KY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Cadima; Paul Bryan
Han; Bai |
Prospect
Louisville |
KY
KY |
US
US |
|
|
Family ID: |
49233197 |
Appl. No.: |
13/437153 |
Filed: |
April 2, 2012 |
Current U.S.
Class: |
126/39E |
Current CPC
Class: |
F23D 14/06 20130101;
F24C 3/085 20130101; F23D 14/14 20130101 |
Class at
Publication: |
126/39.E |
International
Class: |
F24C 3/08 20060101
F24C003/08 |
Claims
1. A gas burner assembly for a cooking appliance, said gas burner
assembly comprising: an outer gas burner configured to provide an
outer cooking flame; and an inner infrared burner configured to
provide an inner cooking flame.
2. The gas burner assembly of claim 1, wherein said inner infrared
burner comprises an infrared ring and a reflector.
3. The gas burner assembly of claim 2, wherein said infrared ring
comprises an annular ring that emits infrared energy inward toward
said reflector.
4. The gas burner assembly of claim 2, wherein said infrared ring
comprises an annular ring that emits infrared energy outward toward
said reflector.
5. The gas burner assembly of claim 2, wherein said infrared ring
comprises a stainless steel mesh material.
6. The gas burner assembly of claim 2, wherein said infrared ring
is substantially vertical.
7. The gas burner assembly of claim 2, wherein said reflector
comprises one or more of a ceramic material, stainless steel, and a
high temperature alloy.
8. The gas burner assembly of claim 1, wherein said inner infrared
burner comprises an infrared surface which extends over a central
region of the assembly.
9. The gas burner assembly of claim 8, wherein said inner infrared
surface comprises a substantially dome shaped surface.
10. The gas burner assembly of claim 1, further comprising a glass
cover over said inner infrared burner.
11. The gas burner assembly of claim 1, wherein said outer gas
burner and said inner infrared burner are substantially
concentric.
12. A gas cooking appliance comprising: a cooktop surface; and a
gas burner assembly comprising: an outer gas burner configured to
provide an outer cooking flame; and an inner infrared burner
configured to provide an inner cooking flame.
13. The gas cooking appliance of claim 12, wherein said inner
infrared burner comprises a reflector and an infrared ring that
emits infrared energy toward said reflector.
14. The gas cooking appliance of claim 13, wherein said infrared
ring comprises an annular ring disposed outwardly of said
reflector.
15. The gas cooking appliance of claim 13, wherein said infrared
ring comprises an annular ring disposed inwardly of said
reflector.
16. The gas cooking appliance of claim 13, wherein said infrared
ring is substantially vertical.
17. The gas cooking appliance of claim 13, wherein said reflector
comprises one or more of a ceramic material, stainless steel, and a
high temperature alloy.
18. The gas cooking appliance of claim 12, wherein said inner
infrared burner comprises a substantially dome-shaped infrared
surface.
19. The gas cooking appliance of claim 12, further comprising a
glass cover over said inner infrared burner.
20. The gas cooking appliance of claim 12, wherein said outer gas
burner and said inner infrared burner are substantially concentric.
Description
BACKGROUND OF THE INVENTION
[0001] The subject matter disclosed herein relates to gas
appliances, such as gas ranges, and more particularly, to
multi-stage surface burners for use in such gas appliances.
[0002] For gas burners that are used as surface heating units in
cooking appliances, such as ranges and cooktops, a high turndown
ratio is generally desirable. A turndown ratio is a ratio of
maximum output to minimum output. For a given burner, the maximum
output typically signifies the "power" or "speed" of the burner and
the minimum output is related to the simmer capability of a burner.
The maximum output is limited by system gas flow handling
capabilities and safety considerations. The minimum output is
limited by the ability of the burner to maintain a stable flame
under transient pressure fluctuations caused, for example, by air
currents in the room, or sudden opening or closing of nearby
cabinet doors or, if applicable, the oven door.
[0003] A number of techniques exist for improving the turndown
ratio of gas burners. For example, multi-ring gas burner assemblies
typically include at least an inner gas burner and an outer gas
burner for collectively producing a plurality of rings of flame to
heat a utensil supported thereon. Most multi-ring burners have
multiple stages that can support flames on all rings simultaneously
for a maximum output or can support flames on less-than-all rings
for a lower output.
[0004] Typically, the smaller inner gas burner must be scaled down
in size to support low output rates. Although the total output of
the smaller inner burner may be relatively low, the heat is focused
on a small area and thus the cookware directly above the inner
burner may be heated too much locally above the inner burner while
the average food load temperature is low (i.e., a gradient is
present in the food load). The use of a diffuser over the inner
burner has been proposed as a technique to help spread the heat, as
well as spacing the inner burner further away from the cookware to
increase diffusion of the heat with air. These techniques, however,
impact the efficiency and performance of the burners when turned up
to a high rate for a maximum output.
[0005] In addition, the center burner of existing multi-ring
burners is a partially pre-mixed blue flame burner. Thus, secondary
air must be supplied to the center burner in order for the center
burner to burn the fuel completely. Thus, air gaps are required
around the center burner to supply the air. These gaps are
generally considered unsightly and make clean-up more
difficult.
[0006] Infrared (IR) burners are generally more efficient than
conventional gas burners and can heat more uniformly over a larger
area. IR burners mix all of the needed air into the gas before the
mixture exits the burner. The mixture exiting the IR burner burns
quickly due to the high amount of air contained therein.
Accordingly, IR burners include small holes from which the gas
escapes quickly in order to keep the mixture from burning back into
the burner.
[0007] As such, a primary difference between normal blue flame
burners and IR burners is that the flame length of an IR burner is
shorter than that of a normal blue flame burner, and much of the
heat released during combustion is absorbed into the burner,
causing the burner to glow hot and re-release the absorbed heat in
the form of radiation instead of purely convective heat.
[0008] IR burners, however, suffer from a poor appearance, a lack
of protection from spills, and they have a substantially lower
turn-down ratio. The typical turn-down ratio for an infrared burner
is on the order of 3-to-1 versus a typical turn-down ratio of
approximately 12-to-1 for a conventional single ring atmospheric
burner. For this reason, IR burners are rarely used for cooktop
surface burners.
[0009] Thus, a need remains for a cooktop burner that can evenly
heat food loads when at the minimum setting while maintaining high
rate performance. A need also remains for a top burner that is
substantially sealed to the cooktop surface without the need for
unsightly gaps to supply secondary air to the center burner.
BRIEF DESCRIPTION OF THE INVENTION
[0010] As described herein, the exemplary embodiments of the
present invention overcome one or more disadvantages known in the
art.
[0011] One aspect of the present invention relates to a gas burner
assembly for a cooking appliance, the gas burner assembly
comprising an outer gas burner configured to provide an outer
cooking flame; and an inner infrared burner configured to provide
an inner cooking flame.
[0012] Another aspect of the present invention relates to a gas
cooking appliance, comprising: a cooktop surface; and a gas burner
assembly. The gas burner assembly further comprises an outer gas
burner configured to provide an outer cooking flame; and an inner
infrared burner configured to provide an inner cooking flame.
[0013] Advantageously, illustrative embodiments of the present
invention provide improved multi-stage burners. The disclosed
multi-stage burners can heat food more evenly when at substantially
minimum settings while maintaining high rate performance.
Additionally, because IR burners mix the air in the fuel before the
fuel burns, use of an IR burner for the center burner eliminates
the need for gaps or spacing around the burner to supply air to the
center, resulting in an improved appearance.
[0014] These and other aspects and advantages of the present
invention will become apparent from the following detailed
description considered in conjunction with the accompanying
drawings. It is to be understood, however, that the drawings are
designed solely for purposes of illustration and not as a
definition of the limits of the invention, for which reference
should be made to the appended claims. Moreover, the drawings are
not necessarily drawn to scale and, unless otherwise indicated,
they are merely intended to conceptually illustrate the structures
and procedures described herein.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] In the drawings:
[0016] FIG. 1 illustrates an embodiment of an exemplary
free-standing gas range;
[0017] FIG. 2 is an exemplary burner assembly applicable to the gas
range shown in FIG. 1; and
[0018] FIGS. 3 through 6 illustrate various exemplary embodiments
of the burner assembly of FIG. 2 in accordance with the present
invention.
DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS OF THE
INVENTION
[0019] One or more illustrative embodiments of the invention will
be described below in the context of a gas cooking appliance in the
form of a gas range. However, it is to be understood that
embodiments of the invention are not intended to be limited to use
with any particular gas appliance. Rather, one or more embodiments
of the invention may be applied to and deployed in any other
suitable environment in which it would be desirable to operate a
gas fueled surface heating unit.
[0020] As illustratively used herein, the term "appliance" is
intended to refer to a device or equipment designed to perform one
or more specific functions. This may include, but is not limited
to, equipment for consumer use, e.g., a gas range or a gas cooktop.
This may include, but is not limited to, any equipment that is
useable in household or commercial environments.
[0021] While the methods and apparatus are herein described in the
context of a gas range, as set forth more fully below, it is
contemplated that the herein described methods and apparatus may
find utility in other applications, including, but not limited to
gas cooktops, gas heater devices, gas ovens, gas kilns, gas-fired
meat smoker devices, and gas barbecues. In addition, the principles
and teachings set forth herein may find equal applicability to
combustion burners for a variety of combustible fuels. The
description below is therefore set forth only by way of
illustration rather than limitation, and any intention to limit
practice of the herein described methods and apparatus to any
particular application is expressly disavowed.
[0022] FIG. 1 illustrates an exemplary free-standing gas range 10
in which the herein described apparatus and methods may be
practiced. Range 10 includes an outer body or cabinet 12 that
incorporates a generally rectangular cooktop 14. An oven, not
shown, is positioned below cooktop 14 and has a front-opening
access door 16. A range backsplash 18 extends upward from a rear
edge 20 of cooktop 14 and contains various control selectors (not
shown) for selecting operative features of heating elements for
cooktop 14 and the oven.
[0023] Cooktop 14 includes four gas fueled burner assemblies 22
which are positioned in spaced apart pairs positioned adjacent each
side of cooktop 14. Each burner assembly 22 extends upward through
an opening in cooktop 14, and a grate 28 is positioned over each
burner assembly 22. Each grate 28 includes a horizontally extending
support structure thereon for supporting cooking vessels.
[0024] Cooktop 14 also includes control devices, such as, knobs 32,
34, 36, and 38 that are manipulated by a user to adjust the setting
of a corresponding gas valve (not shown) to control the amount of
heat output from the corresponding one of burner assemblies 22. For
example, rotating knob 32 in one direction switches the valve from
off to the full on position. Continued rotation gradually moves the
valve from the full open position to the minimum setting position.
Accordingly, the user may adjust the heat output of the
corresponding burner to the desired level.
[0025] It is contemplated that the herein described apparatus and
methods are applicable, not only to cooktops which form the upper
portion of a range, such as range 10, but to other forms of
cooktops as well, such as, but not limited to, cooktops that are
mounted to a kitchen counter. Therefore, range 10 is provided by
way of illustration rather than limitation, and accordingly there
is no intention to limit application of the herein described
apparatus and methods to any particular appliance or cooktop, such
as range 10 or cooktop 14. It is also to be understood that there
can be any other number of burner assemblies or any combination of
burner assemblies and other type of cooking surfaces, such as
grills and hot plates, included in cooktop 14.
[0026] FIG. 2 is an exemplary burner assembly 50 applicable to gas
range 10 shown in FIG. 1. Burner assembly 50 is mounted on a
cooktop surface 52 of a cooktop 54, and includes an inner IR burner
60, and an outer gas burner 62 concentric with inner IR burner 60.
A number of alternate embodiments of the inner IR burner 60 are
discussed further below in conjunction with FIGS. 3 through 6. The
particular embodiment of the burner assembly 50 shown in FIG. 2
corresponds to a first embodiment, the details of which are
discussed further below in conjunction with FIG. 3. In the
exemplary embodiment, cooktop 54 is fabricated from one of steel or
glass. Alternatively, cooktop 54 is made of other suitable
materials.
[0027] The exemplary gas surface burner 50 of FIG. 2 employs a
hybrid approach to surface burners that seeks to take advantage of
the benefits of both premixed and atmospheric partially premixed
burners. As discussed further below, according to one aspect of the
invention, the inner burner 60 is embodied as an IR burner (such as
described herein). In the exemplary gas surface burner 50 of FIG.
2, the outer gas burner 62 is embodied as a burner which supports a
partially premixed air/fuel flame on the outer ring of ports and
the inner burner 60 is embodied as a burner which supports a fully
premixed air/fuel IR flame. Among other benefits, the exemplary gas
surface burner 50 of FIG. 2 realizes uniform heating at low firing
rates. It is noted that at lower firing rates, the outer burner 62
is turned off and only the inner IR burner 60 remains on.
[0028] The present invention recognizes that radiant or IR burners,
such as the inner burners 60, radiate a significant portion of
their energy output in the infrared spectrum rather than heating by
convection. Thus, a number of exemplary reflectors and/or radiators
can optionally be employed to direct the heat uniformly to a broad
area.
[0029] FIG. 3 illustrates a first exemplary embodiment 300 of the
multi-ring burner assembly 50 of FIG. 2. In the exemplary burner
assembly 300 of FIG. 3, the central simmer burner 360 is embodied
as an annular IR ring 310 that emits IR energy inward towards a
centrally located parabolic reflector 320. The exemplary annular IR
ring 310 is substantially vertical, that is, it extends axially in
a substantially vertical direction relative to the plane of the
supporting surface, and can be fabricated, for example, using a
stainless steel mesh. The parabolic reflector 320 can be
fabricated, for example, using a ceramic material, stainless steel,
or another high temperature alloy, such as Inconel.TM.. The shape
of the reflector 320 may be manipulated to control the heat flux to
the cookware, as would be apparent to a person of ordinary skill in
the art. The outer gas burner 362 includes a plurality of ports 370
to support traditional blue flames.
[0030] Among other benefits, an overhang 315 of the burner cap of
the exemplary multi-ring burner assembly 300 of FIG. 3
substantially hides the unattractive IR porous medium of the
annular IR ring 310 from sight.
[0031] FIG. 4 illustrates another exemplary embodiment 400 of the
burner assembly 50 of FIG. 2. In the exemplary multi-ring burner
assembly 400 of FIG. 4, the central simmer burner 460 is embodied
as an annular IR ring 410 that emits IR energy (for example, heat)
outward towards an outer, concentrically located reflector 420. The
exemplary annular IR ring 410 is substantially vertical and can be
fabricated, for example, using a stainless steel mesh. The
reflector 420 can be fabricated, for example, using a ceramic
material, stainless steel, or another high temperature alloy, such
as Inconel.TM.. The shape of the reflector 420 may be manipulated
to control the heat flux to the cookware, as would be apparent to a
person of ordinary skill in the art. The outer gas burner 462
includes a plurality of ports 470 to support traditional blue
flames.
[0032] Among other benefits, the exemplary multi-ring burner
assembly 400 of FIG. 4 substantially hides the unattractive IR
porous medium of the annular IR ring 410 from sight by using an
optional cap 430.
[0033] FIG. 5 illustrates another exemplary embodiment 500 of a
burner assembly 50 of FIG. 2. In the exemplary burner assembly 500
of FIG. 5, the inner burner 560 is embodied as a centrally
positioned IR burner surface 510 that extends over the central
region of the burner assembly in a configuration that realizes a
substantially improved high rate performance. The IR surface 510
can be fabricated, for example, using a stainless steel mesh. An
annular reflector 520 which is disposed outwardly of the central
region covered by surface 510 can optionally be included to direct
the heat, as discussed above. The reflector 520 can be fabricated,
for example, using a ceramic material, stainless steel, or another
high temperature alloy, such as Inconel.TM.. The shape of the
reflector 520 may be manipulated to control the heat flux to the
cookware, as would be apparent to a person of ordinary skill in the
art. The outer gas burner 562 includes a plurality of ports 570 to
support traditional blue flames.
[0034] In one particular implementation of the exemplary embodiment
500 of FIG. 5, the centrally positioned firing IR surface 510 has a
substantial dome shape to increase diffusion of the heat to the
cooking utensil. In this manner, the heat is better distributed. In
this manner, the cookware directly above the inner burner 560 is
heated more uniformly and the food load temperature gradient is
improved.
[0035] FIG. 6 illustrates a fourth exemplary embodiment 600 of the
burner assembly 50 of FIG. 2. The fourth exemplary embodiment 600
of FIG. 6 recognizes that the heat in the embodiment of FIG. 5
would tend to be more focused at simmer rates. Thus, the fourth
exemplary embodiment 600 of FIG. 6 adds a ceramic piece of glass
610 to the other elements of the embodiment of FIG. 5 to diffuse
the heat. This glass piece 610 transmits much of the IR spectrum
and diffuses the convective portion of the heat output while
providing full protection from spills.
[0036] It is noted that the glass piece 610 of FIG. 6 may be added
in a similar manner to each of the embodiments of the burner
assembly 300, 400, 500. The glass piece 610 can be fixedly or
removably mounted to the burner assembly 300, 400, 500.
[0037] For a more detailed discussion of a gas burner (for example,
multi-ring gas burner) assembly employing blue flame burners for
both the inner and outer burner, see, for example, United States
Publication No. 2007/0154858, entitled "Gas Burner Assembly
Including Inner and Outer Burners and Methods for Implementing
Same," assigned to the assignee of the present invention and
incorporated by reference herein.
[0038] Thus, while there have been shown and described and pointed
out fundamental novel features of the invention as applied to
exemplary embodiments thereof, it will be understood that various
omissions and substitutions and changes in the form and details of
the devices illustrated, and in their operation, may be made by
those skilled in the art without departing from the spirit of the
invention. Moreover, it is expressly intended that all combinations
of those elements and/or method steps which perform substantially
the same function in substantially the same way to achieve the same
results are within the scope of the invention. Furthermore, it
should be recognized that structures and/or elements and/or method
steps shown and/or described in connection with any disclosed form
or embodiment of the invention may be incorporated in any other
disclosed or described or suggested form or embodiment as a general
matter of design choice. It is the intention, therefore, to be
limited only as indicated by the scope of the claims appended
hereto.
* * * * *