U.S. patent application number 12/898903 was filed with the patent office on 2012-04-12 for apparatus and method for improved ignition of a gaseous fuel burner in an appliance.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Jose Hernandez Burgos, Gabriel Gonzalez, Eduardo Ludlow, Daniel Joseph Trice, John Adam Yantis.
Application Number | 20120088199 12/898903 |
Document ID | / |
Family ID | 45925413 |
Filed Date | 2012-04-12 |
United States Patent
Application |
20120088199 |
Kind Code |
A1 |
Yantis; John Adam ; et
al. |
April 12, 2012 |
APPARATUS AND METHOD FOR IMPROVED IGNITION OF A GASEOUS FUEL BURNER
IN AN APPLIANCE
Abstract
A method and apparatus for improved ignition of a gaseous fuel
in an appliance is provided. More particularly, the shielding of an
igniter and the use of thermal convection to direct a flow of
gaseous fuel and air across a hot surface of the igniter in order
to create proper conditions for the ignition of the gaseous fuel is
described.
Inventors: |
Yantis; John Adam;
(Louisville, KY) ; Trice; Daniel Joseph;
(Louisville, KY) ; Burgos; Jose Hernandez;
(Queretaro, MX) ; Ludlow; Eduardo; (Queretaro,
MX) ; Gonzalez; Gabriel; (Queretaro, MX) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
45925413 |
Appl. No.: |
12/898903 |
Filed: |
October 6, 2010 |
Current U.S.
Class: |
431/12 ;
431/255 |
Current CPC
Class: |
F23D 14/70 20130101;
F23D 2207/00 20130101; F23D 14/76 20130101; F23Q 7/10 20130101;
F23D 14/58 20130101; F23D 2203/1017 20130101 |
Class at
Publication: |
431/12 ;
431/255 |
International
Class: |
F23N 1/00 20060101
F23N001/00; F23Q 7/06 20060101 F23Q007/06 |
Claims
1. A shield for the igniter of a gaseous fuel burner, comprising: a
housing positioned around the igniter, said housing defining an
entrance opening for the flow of the gaseous fuel into said
housing, the entrance opening positioned lower than the igniter,
said housing also defining an exit opening for the flow of air and
gaseous fuel across the igniter and out of said housing, the exit
opening positioned higher than the igniter; and a gaseous fuel
receptacle configured with the housing at a position lower than the
igniter, said gaseous fuel receptacle positioned for gaseous
communication with the entrance opening of said housing wherein
gaseous fuel drawn into said gaseous fuel receptacle may travel
through the entrance opening of said housing.
2. A shield for the igniter of a gaseous fuel burner as in claim 1,
wherein said gaseous fuel receptacle is positioned directly below
said gaseous fuel burner.
3. A shield for the igniter of a gaseous fuel burner as in claim 1,
wherein said gaseous fuel receptacle is configured as a tray.
4. A shield for the igniter of a gaseous fuel burner as in claim 3,
wherein said tray is positioned at least partly below said gaseous
fuel burner.
5. A shield for the igniter of a gaseous fuel burner as in claim 1,
wherein said housing and said gaseous fuel receptacle are
integrally constructed.
6. A shield for the igniter of a gaseous fuel burner as in claim 1,
further comprising a protective grill connected with said housing
and positioned over said igniter.
7. A shield for the igniter of a gaseous fuel burner as in claim 1,
wherein said gaseous fuel receptacle is positioned for the receipt
of gaseous fuel flowing from said gaseous fuel burner.
8. A shield for the igniter of a gaseous fuel burner as in claim 1,
wherein said housing and said gaseous fuel receptacle are
positioned to create a flow of air and gaseous fuel across said
igniter from thermal convection caused by heating said igniter.
9. A shield for the igniter of a gaseous fuel burner as in claim 1,
wherein said housing and said gaseous fuel receptacle are
positioned to create an ignitable flow of air and gaseous fuel
across the igniter within four seconds of supplying gaseous fuel to
the gaseous fuel burner.
10. A method for igniting a gaseous fuel burner, comprising the
steps of: providing a shield about the gaseous fuel burner;
supplying a gaseous fuel to the gaseous fuel burner; raising the
temperature of a surface of an igniter to a temperature sufficient
to ignite a mixture comprising the gaseous fuel and air; heating
with the igniter so as to create a flow by thermal convection of
the mixture; using the shield to channel the flow upward and across
the surface of the igniter; and igniting the mixture of air and
gaseous fuel flowing across the igniter.
11. A method for igniting a gaseous fuel burner as in claim 10,
wherein said using step comprises moving gas from the gaseous fuel
burner downward to a position lower than the igniter and then
upward and across the surface of the igniter.
12. A method for igniting a gaseous fuel burner as in claim 10,
wherein said using step further comprises: providing a gaseous fuel
receptacle at a position lower than the gaseous fuel burner; and
receiving gaseous fuel into the gaseous fuel receptacle after said
step of heating with the igniter.
13. A method for igniting a gaseous fuel burner as in claim 12,
further comprising the step of positioning the gaseous fuel
receptacle at a position lower than the igniter.
14. A method for igniting a gaseous fuel burner as in claim 10,
wherein said igniting step occurs within about four seconds of said
supplying step.
15. A method for igniting a gaseous fuel burner as in claim 10,
further comprising the step of providing a control valve upstream
of the gaseous fuel burner, and wherein said supplying step
comprises opening the control valve.
16. A method for igniting a gaseous fuel burner as in claim 15,
wherein said igniting step occurs within about four second of
opening the control valve.
17. A method for igniting a gaseous fuel burner as in claim 10,
further comprising the step of minimizing the accumulation of
un-ignited, gaseous fuel near the gaseous fuel burner after said
step of supplying.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a method and apparatus for
improved ignition of a gaseous fuel in an appliance. More
particularly, the present invention provides for a method and
apparatus for shielding an igniter so as to create improved
conditions for the ignition of a gaseous fuel.
BACKGROUND OF THE INVENTION
[0002] For purposes of fuel ignition, gas burner control systems in
modern appliances such as a gas oven may use what is referred to as
glow bar or hot surface igniters (referred to herein as "igniter").
Typically, such igniters include resistive elements that are heated
by the application of an electrical current. The hot surface of the
igniter is generally positioned adjacent to a flow of a gaseous
fuel. The flow of gaseous fuel is controlled by a manual or
electrically operated gas control valve. To achieve ignition,
current is applied to the igniter until it reaches a temperature
high enough to cause ignition of the gaseous fuel. The gas control
valve is then opened and if the proper mixture of air and gaseous
fuel is present, ignition occurs and heat is created.
[0003] Once the flow of gas is initiated, it is desirable that
ignition take place relatively quickly so as to avoid a dangerous
build-up of gas in the appliance. Standards such as the National
Fuel Gas Code generally set forth limits on the amount of time a
gaseous fuel can be allowed to flow before ignition occurs. For
example, for certain appliances, a maximum interval of four seconds
is allowed for gas flow between the opening and shutting of the
gaseous fuel control valve if ignition has not occurred.
[0004] Accordingly, the igniter is typically placed close to the
gas burner to minimize the distance over which the gaseous fuel
must diffuse before reaching the igniter. Ignition of the gaseous
fuel requires both a surface at a high enough temperature and the
presence, at the heated igniter surface, of the proper mixture of
both gaseous fuel and air. The resulting flame is then fed by
gaseous fuel from the burner.
[0005] Simply placing the igniter adjacent to the burner may not
ensure a relatively quick ignition of the gaseous fuel and may not
be practical. For example, it may be desirable to shield the
igniter from damage such that placement directly adjacent the
gaseous fuel burner is not practical. In addition, air currents
within an appliance, delays in gas flow after opening the valve,
and other factors can contribute to unsatisfactory conditions for
ignition.
[0006] Accordingly, a method and apparatus for improved ignition of
gaseous fuel for an appliance burner would be useful. More
specifically, a method and apparatus for reducing the time required
for ignition while also eliminating the accumulation of gaseous
fuel would be particularly beneficial. Such an invention that can
also be used with a shield for the igniter would also provide
additional utility.
BRIEF DESCRIPTION OF THE INVENTION
[0007] Aspects and advantages of the invention will be set forth in
part in the following description, or may be obvious from the
description, or may be learned through practice of the
invention.
[0008] In an exemplary embodiment of the present invention, a
shield for the igniter of a gaseous fuel burner of an appliance is
provided. The shield includes a housing positioned around the
igniter. The housing defines an entrance opening for the flow of
the gaseous fuel into the housing. The entrance opening is
positioned lower than the igniter. The housing also defines an exit
opening for the flow of air and gaseous fuel across the igniter and
out of the housing. The exit opening is positioned higher than the
igniter. A gaseous fuel receptacle is configured with the housing
at a position lower than the igniter. The gaseous fuel receptacle
is positioned for gaseous communication with the entrance opening
of the housing so that gaseous fuel drawn into the gaseous fuel
receptacle may travel through the entrance opening of the
housing.
[0009] In another exemplary aspect of the present invention, a
method for igniting a gaseous fuel burner of an appliance is
provided. The method includes the steps of providing a shield about
the gaseous fuel burner; supplying a gaseous fuel to the gaseous
fuel burner; raising the temperature of a surface of an igniter to
a temperature sufficient to ignite a mixture comprising the gaseous
fuel and air; heating with the igniter so as to create a flow by
thermal convection of the mixture; using the shield to channel the
flow upward and across the surface of the igniter; and igniting the
mixture of air and gaseous fuel flowing across the igniter.
[0010] These and other features, aspects and advantages of the
present invention will become better understood with reference to
the following description and appended claims. The accompanying
drawings, which are incorporated in and constitute a part of this
specification, illustrate embodiments of the invention and,
together with the description, serve to explain the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] A full and enabling disclosure of the present invention,
including the best mode thereof, directed to one of ordinary skill
in the art, is set forth in the specification, which makes
reference to the appended figures, in which:
[0012] FIG. 1 provides a perspective view of an exemplary
embodiment of an igniter shield of the present invention.
[0013] FIG. 2 provides a cross-sectional view of the exemplary
embodiment of FIG. 1 installed with a gaseous fuel burner of an
appliance.
DETAILED DESCRIPTION OF THE INVENTION
[0014] The present invention provides a method and apparatus for
improved ignition of a gaseous fuel in an appliance. More
particularly, the present invention provides for shielding an
igniter and using thermal convection to direct a flow of gaseous
fuel and air across the hot surface of the igniter to create proper
conditions for the ignition of the gaseous fuel. By directing the
flow of gaseous fuel, unnecessary accumulation of gaseous fuel
within the appliance can be avoided. Reference now will be made in
detail to embodiments of the invention, one or more examples of
which are illustrated in the drawings. Each example is provided by
way of explanation of the invention, not limitation of the
invention. In fact, it will be apparent to those skilled in the art
that various modifications and variations can be made in the
present invention without departing from the scope or spirit of the
invention. For instance, features illustrated or described as part
of one embodiment can be used with another embodiment to yield a
still further embodiment. Thus, it is intended that the present
invention covers such modifications and variations as come within
the scope of the appended claims and their equivalents.
[0015] FIG. 1 provides a perspective view of an exemplary
embodiment of a shield 100 of the present invention. For additional
clarity, shield 100 is shown in isolation from a gas appliance.
FIG. 2 is a cross-sectional view of the shield 100 installed within
an appliance such as a gas oven appliance. A broil burner tube 10
along with a mesh screen or burner surface 20 is configured with
burner housing 30 and installed in the top of a cooking
compartment. It should be understood that the present invention may
be used in a variety of appliances that utilize a burner element
supplied by a gaseous fuel that must be ignited during use. Such
gaseous fuels as may be used with the present invention include,
for example, propane and natural gas.
[0016] Referring to both FIGS. 1 and 2, shield 100 includes a
housing 110 that is positioned around positioned around an igniter
105. Leads 115 attached to connector 120 and igniter 105 provide
electrical power to igniter 105. Upon activation, fingers 125 of
igniter 105 become heated and will eventually reach a temperature
sufficient to ignite a combustible mixture of air and a gaseous
fuel. Igniter 105 is of the hot surface or glow type. Other shapes
and configurations other than fingers 125 may be used.
[0017] Housing 110 defines an entrance opening 130 for the flow
gaseous fuel into housing 110 as illustrated by arrows A in FIG. 1.
Entrance opening 130 is positioned lower than the igniter to
facilitate the flow of gaseous fuel and air (including a mixture
thereof) into housing 110 by thermal convection as more fully
described below. Although shown as rectangular in shape, it should
be understood that other shapes for entrance opening 130 may be
used provided the opening is positioned to allow gaseous fuel and
air to be drawn into housing 110.
[0018] Housing 110 also defines an exit opening 135 for the flow of
gaseous fuel and air across igniter 105 and out of housing 110 as
illustrated by arrows B in FIG. 1. Exiting opening 135 is
positioned higher than igniter 105 so that gaseous fuel and air
rising from igniter 105 may exit housing 110 (higher being defined
relative to the flow of gas once heated by igniter 105). Again,
although shown with a rectangular shape, exit opening 135 may be
constructed with other shapes provided an opening is allowed for
the flow of gas from and across igniter 105. Housing 110 also
includes a protective grill 140 with apertures 145. Grill 140
serves to protect igniter 105 from contact damage while apertures
145 allow for the flow of gas and conduction of heat.
[0019] A gaseous fuel receptacle 150 is positioned adjacent to
housing 110. As shown in FIGS. 1 and 2, gaseous fuel receptacle 150
is constructed as a tray having walls 155 and bottom 160. As
illustrated by arrows A and their movement into entrance opening
130 of housing 110, gaseous fuel receptacle 150 is positioned for
gaseous communication with the entrance opening 130 of housing 110.
More specifically, gaseous fuel from burner tube 10 and air can be
drawn into the gaseous fuel receptacle 150 and pass into housing
110 for passage across igniter 105. Other shapes and configurations
for gaseous fuel receptacle 150 may used provided such allow for
the receipt and flow of fuel from burner tube 10 and air as
described. In addition, FIG. 2 depicts gaseous fuel receptacle 150
at a position directly below the surface of burner 20. However,
other positions may used as well provided receptacle 150 is
positioned for the receipt of gaseous fuel and air as stated.
[0020] For the exemplary embodiment of FIGS. 1 and 2, shield 100 is
shown as an integral or unitary construction of housing 110 and
gaseous fuel receptacle 150. For example, sheet metal may be
punched or stamped into the desired shaped for both housing 110 and
gaseous fuel receptacle 150. However, other constructions may be
used including the connection of separate components by fasteners,
tabs, or the like. Materials used must be compatible with the
temperatures created by burner tube 10 and igniter 105.
[0021] Accordingly, in operation, igniter 105 is activated so that
the temperature of the surface (such as fingers 125) of igniter 105
is raised to a temperature sufficient to ignite a combustible
mixture of gaseous fuel and air. A gaseous fuel such as propane or
natural gas is supplied to burner tube 10. For example, a control
valve (not shown) may be positioned upstream of burner tube 10 for
determining the flow to burner tube 10. Gaseous fuel exits tube 10
and diffuses through burner 20 while mixing with air in the
appliance.
[0022] As the temperature of igniter 105 increases, air and/or
gaseous fuel proximate to igniter 105 will be heated and thermal
convection will occur. More specifically, due to density
differences from heating the gas surrounding igniter 105, such gas
will begin to rise (as shown by arrows B) to create a flow across
the surface of igniter 105 and out of housing 110 through exit
opening 135. As a result, gaseous fuel and air will be drawn down
into gaseous fuel receptacle 150 to enter into housing 110 through
entrance opening 130. More specifically, due to the configuration
of housing 110 and receptacle 150, shield 100 will channel a flow
of gaseous fuel, air, or a mixture of both upward and across the
surface of the igniter. Once a combustible mixture of air and
gaseous fuel pass over igniter 105 when it is at a sufficiently
raised temperature, the mixture will be ignited. Flame will then
spread rapidly along burner 20 to ignite gaseous fuel and heat the
appliance.
[0023] By using gaseous fuel receptacle 150 to capture fuel as it
leaves burner 20 and channel the same across a properly heated
igniter 105, the unnecessary accumulation of un-ignited fuel within
the appliance can be avoided. Ignition of the gaseous fuel in a
relatively short period of time after supplying such fuel to burner
tube 10 can be accomplished. More specifically, and by way of
example, a four second interval or less between the beginning of a
flow of gaseous fuel to burner tube 10 and the ignition of such
fuel can be achieved.
[0024] This written description uses examples to disclose the
invention, including the best mode, and also to enable any person
skilled in the art to practice the invention, including making and
using any devices or systems and performing any incorporated
methods. The patentable scope of the invention is defined by the
claims, and may include other examples that occur to those skilled
in the art. Such other examples are intended to be within the scope
of the claims if they include structural elements that do not
differ from the literal language of the claims, or if they include
equivalent structural elements with insubstantial differences from
the literal languages of the claims.
* * * * *