US20170009982A1

US20170009982A1 - Ultra low nox insulating burner without collar

Info

Publication number: US20170009982A1
Application number: US15/204,651
Authority: US
Inventors: Duane D. Garloch; Robert Shaw; Nicholas Kamm
Original assignee: Carrier Corp
Current assignee: Carrier Corp
Priority date: 2015-07-09
Filing date: 2016-07-07
Publication date: 2017-01-12

Abstract

A burner comprising is provided including a burner tube formed at least partially from a first material having a plurality of openings. The plurality of openings are sized to allow a fluid but not particles of debris contained within the fluid to flow there through. A flange extends outwardly from a portion of the burner tube and is receivable within an embossment formed in an adjacent component. The flange is formed from a second material having a plurality of openings such that heat transfer between the flange and the adjacent component is limited.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. provisional patent application Ser. No. 62/190,576 filed Jul. 9, 2015, the entire contents of which are incorporated herein by reference.

BACKGROUND

The subject matter disclosed herein relates to heating systems. More specifically, the subject disclosure relates to burners for residential and commercial heating systems.
Heating systems, in particular furnaces, include one or more burners for combusting a fuel such as natural gas. Hot flue gas from the combustion of the fuel proceeds from the burner and through a heat exchanger. The hot flue gas transfers thermal energy to the heat exchanger, from which the thermal energy is then dissipated by a flow of air driven across the heat exchanger by, for example, a blower.
A typical prior art construction is shown in FIG. 1. A burner 100 is located external to a heat exchanger 102. The burner 100, often referred to as an inshot burner 100, receives a flow of fuel from a fuel source 104. An ignition source 106 combusts the flow of fuel to create a combustion flame 110.
Another type of burner is a premix burner in which fuel and air are mixed in a burner inlet tube prior to injection into a combustion zone 112 where the ignition source 106 ignites the mixture. Premix burners, compared to inshot burners, typically emit much lower levels of NO_N, the emissions of which are tightly regulated and restricted by many jurisdictions. Because of this advantage of premix burners, it may be desirable to utilize premix burners in furnaces.
In multi-burner applications such as furnaces, each heat exchanger is supplied with hot combustion products by individual burners. Typically, each burner is mounted to a partition plate of the burner assembly with a metallic flange to direct the flow of hot combustion products towards the heat exchanger. As the flame exits each burner, the flame flows across each burner flange causing the flange to become hot. Due to the highly conductive nature of the flange, the heat of the flame is transferred to the partition plate via the flanges, resulting in damage and/or deformation of the partition plate.

BRIEF DESCRIPTION

According to one embodiment, a burner is provided including a burner tube formed at least partially from a first material having a plurality of openings. The plurality of openings are sized to allow a fluid but not particles of debris contained within the fluid to flow there through. A flange extends outwardly from a portion of the burner tube and is receivable within an embossment formed in an adjacent component. The flange is formed from a second material having a plurality of openings such that heat transfer between the flange and the adjacent component is limited.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is positioned at an outlet end of the burner tube.
In addition to one or more of the features described above, or as an alternative, in further embodiments the first material having a plurality of openings and the second material having a plurality of openings are substantially identical.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is integrally formed with a portion of the burner tube.
In addition to one or more of the features described above, or as an alternative, in further embodiments the first material having a plurality of openings and the second material having a plurality of openings are different.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is removably or fixedly coupled to a portion of the burner tube.
In addition to one or more of the features described above, or as an alternative, in further embodiments when the flange is received within the embossment, the flange does not extend beyond a plane defined by the a surface of the adjacent component.
A burner assembly is provided including a plurality of burners. Each burner includes a burner tube defining a burner axis. The burner tubes have an inlet, an outlet, and a flange extending outwardly from a portion of the burner tube. A partition plate is arranged generally perpendicular to a horizontal plane containing the plurality of burner axes. The partition plate includes a plurality of partition openings complementary to and arranged coaxially with the plurality of burners. The flange of each burner is configured to mount to the partition plate, the flange being configured to limit heat transfer between the burner and the partition plate.
In addition to one or more of the features described above, or as an alternative, in further embodiments a lock plate mounted positioned adjacent a surface of the partition plate. The lock plate being configured to engage a portion of at least one of the plurality of flanges to restrict movement of a burner away from the partition plate.
In addition to one or more of the features described above, or as an alternative, in further embodiments the partition plate includes a plurality of embossments. Each of the plurality of flanges being receivable within one of the plurality of embossments.
In addition to one or more of the features described above, or as an alternative, in further embodiments a thickness of the flanges is less than a depth of the embossments.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is arranged at an outlet end of each of the plurality of burner tubes.
In addition to one or more of the features described above, or as an alternative, in further embodiments the burner tube is formed from a first material having a plurality of openings. The plurality of openings being sized to allow a fluid, but not particles of debris contained within the fluid to flow there through.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is formed from a second material having a plurality of openings.
In addition to one or more of the features described above, or as an alternative, in further embodiments the first material having a plurality of openings and the second material having a plurality of openings are substantially identical.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is integrally formed with a portion of the burner tube.
In addition to one or more of the features described above, or as an alternative, in further embodiments the first material having a plurality of openings and the second material having a plurality of openings are different.
In addition to one or more of the features described above, or as an alternative, in further embodiments the flange is removably or fixedly coupled to a portion of the burner tube.
These and other advantages and features will become more apparent from the following description taken in conjunction with the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The subject matter, which is regarded as the present disclosure, is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The foregoing and other features, and advantages of the present disclosure are apparent from the following detailed description taken in conjunction with the accompanying drawings in which:

FIG. 1 is a cross-sectional view of an example of a typical prior art burner arrangement;

FIG. 2 is a schematic view of an embodiment of a furnace; and

FIG. 3 is a fully exploded view of a burner box according to an embodiment of the present disclosure;

FIG. 4 is a perspective view of a burner tube according to an embodiment of the present disclosure; and

FIG. 5 is a cross-sectional view of the burner tube of FIG. 4 mounted to a partition plate according to an embodiment of the present disclosure.

The detailed description explains embodiments of the present disclosure, together with advantages and features, by way of example with reference to the drawings.

DETAILED DESCRIPTION

Referring now to FIG. 2, an improved furnace 20 is illustrated. The furnace 20 may include a heat exchanger 22 having a plurality of individual heat exchanger coils 24. The heat exchanger coils 24, which may be metallic conduits, may be provided in a serpentine fashion to provide a large surface area in a small overall volume of space. Each heat exchanger coil 24 includes an inlet 26 and outlet 28. A burner assembly 29 includes a burner 30 operatively associated with each inlet 26, and a vent 32 operatively associated with each outlet 28. The burner assembly 29 introduces a flame and combustion gases (not shown) into the heat exchanger coil 24, while vent 32 releases the combustion gases to atmosphere (through a flue or the like) after the heat of the flame and combustion gases is extracted by the heat exchanger 22.
In order to extract the heat, a blower motor 36 may be provided to create a significant air flow across the heat exchanger coils 24. As the air circulates across the coils 24, it is heated and can then be directed to a space to be heated such as a home or commercial building for example, by way of appropriate ductwork as indicated by arrow 37. The furnace 20 may also include a return 38 to enable air from the space to be heated to be recirculated and/or fresh air to be introduced for flow across the heat exchanger coils 24.
Referring to FIG. 3, to generate the flame and hot combustion gases, the burners 30 pre-mix fuel and air and then ignite the same. The fuel may be natural gas or propane and may be introduced by a fuel orifice or jet 42 (FIG. 3) positioned at an inlet of a burner inlet tube 61. A portion or substantially all of the air and fuel for combustion is introduced into the burners 30 through inlet 60. Alternatively, air and fuel for combustion may be directly introduced to each burner 30. Referring back to FIG. 2, air may be introduced by inducing an airflow using a motorized induction fan 50 downstream of a burner outlet 48. More specifically, a motor 52 having the fan 50 associated therewith may be operatively associated with the outlets 28 of the heat exchanger coils 24. When energized, the fan 50 may rotate and induce an air flow through the heat exchanger coils 24 and burners 30. Control of the motor 52, may be controlled by a processor 54 such as an integrated furnace control (IFC).
Referring now to FIGS. 3-6, the burner assembly 29 is illustrated in more detail. As indicated above, each burner 30 includes a burner tube 61 having an inlet 60, an outlet 48, and a burner axis X. The burner tube 61 may be provided in a plurality of configurations. For example, while depicted as a cylindrical tube of constant diameter, the burner tube 61 may be provided as a restricted diameter section or a venturi, among other variations.
At least a portion, or all, of the plurality of burners 30 may be arranged within an interior mixing chamber (not shown) of an outer box 62. Fuel supplied by the fuel jet 42 and air drawn by inducer fan 50 are premixed and supplied to the mixing chamber prior to ignition. The burners 30 may additionally include a mixer (not shown) which is used to decrease lean blow-off and increase the stability of the flame. To light the burners 30, at least one igniter 56 is located near the burners 30, generally between the burner outlet 48 and the heat exchanger 22 to ignite the fuel/air mixture. A flame sensor 58 may be mounted adjacent one or more of the burners 30 to detect whether the fuel/air mixture therein has been ignited.
The burners 30 are positioned within the mixing chamber such that the outlet 48 of the burner 30 is adjacent an open end 66 of the box 62. Connected to the open end 66 of the box 62 and the outlet end 48 of each of the plurality of burners 30 is a partition plate 68. A gasket 67 may be arranged between a portion of the open end 66 of box 62 and an outer flange 69 of the partition plate 68 to provide a seal there between. The partition plate 68 has a plurality of openings 70 formed therein, each of which is substantially aligned with and fluidly coupled to the outlet 48 of a corresponding burner 30. In another embodiment, a portion of the burner tubes 61 may extend through the openings 70 formed in the partition plate 68.
An inner box 72 is coupled to the partition plate 68, opposite the outer box 62. A gasket 71 may similarly be arranged between a portion partition plate 68 and the inner box 72 to form a seal there between. In an embodiment, the inner box 72 may be integrated with the partition plate 68. The inner box 72 also includes a plurality of openings 74, each of which is substantially aligned with and fluidly coupled to an opening 70 formed in the partition plate 68 and the outlet 48 of a corresponding burner 30. The individual heat exchanger coils 24 are positioned adjacent an exterior surface 76 of the inner box 72, in line with the plurality of openings 74, such that a fluid flow path extends along a burner axis X from the burner outlet 48 through the partition plate 68 and inner box 72 into the heat exchanger coils 24. In the illustrated, non-limiting embodiment of FIG. 3, a refractory panel 78 is arranged between a portion of the partition plate 68 and the inner box 72. The refractory panel 78 is configured to protect not only the adjacent surface of the inner box 72, but also the interface between the inner box 72 and the heat exchanger coils 24, from overheating. As shown in the exploded view of FIG. 3, the refractory panel 78 includes a plurality of openings 79, each of which is substantially aligned with and fluidly coupled to an opening 70, 74 of the partition plate 68 and inner box 72, respectively.
Referring now to FIG. 4, an example of a burner tube 61 is illustrated in more detail. As shown, at least a portion of the burner tube 61 is formed from a metal mesh or screen-like material including a plurality of small openings. The mesh material may be used to define the burner inlet 60, such as extending generally about the circumference of the burner tube 61. The openings (not shown) in the material are sized such that a fluid flow, but not debris or other particles contained therein, may pass through the material into the interior of the burner tube 61.
A flange 80 extending outwardly from an exterior surface of the burner tube 61 is used to mount the burner tube 61 to the partition plate 68. In the illustrated, non-limiting embodiment, the flange 80 is formed at the outlet end 48 of the burner tube 61. However, burners 30 where the flange 80 is arranged at a position along the burner tube 61, spaced away from the outlet end 48 by a distance, are also within the scope of the disclosure. The flange 80 is additionally formed from a mesh or screen-like material and is configured to withstand temperatures up to and exceeding 2300° F. The material of the flange 80 may, but need not be formed from the same material as the burner tube 61. In addition, the flange 80 may be integrally formed with the burner tube 61, or alternatively, may be a separate component removably or fixedly coupled to the burner tube 61.
Referring now to FIG. 5, the size and shape of the flange 80 may be similar to the shape and size of an embossment 73 formed in the partition plate 68. As a result, when the burner tube 61 is mounted to the partition plate 68, at least a portion of the flange 80 is received within the embossment 73. In one embodiment, as illustrated in FIG. 5, a thickness of the flange 80 is less than the depth of the embossment 73 such that when the flange 80 is positioned within the embossment 73, the flange 80 does not protrude beyond a plane B defined by an adjacent surface 77 of the partition plate 68.
A lock plate 90 may be configured to mount to the surface 77 of the partition plate 68 to couple the burner tubes 61 thereto. The lock plate 90 engages at least a portion of a first surface 82 of the flange 80 and the embossment 73 contacts at least a portion of a second surface 84. By positioning the lock plate 90 and an embossment 73 of the partition plate 68 adjacent opposing sides of the flange 80 of a burner tube 61, translational movement of the burner tube 61 along the burner axis X, away from the partition plate 68, is restricted. In the illustrated, non-limiting embodiment, the lock plate 90 includes at least one opening 92 having a diameter equal to or greater than a diameter of a burner tube 61 such that the burner tube 61 may be received therein. However, a lock plate 90 having another configuration is also within the scope of the disclosure.
A burner tube 61 as described herein allows premixed fuel and air to flow through the completer length of the burner 30. This allows the area where the burner 30 mounts to the partition plate 68 to be cooler than in existing systems. In addition, by forming the flange 80 out of a mesh material, a limited amount of movement of the burner 30 may occur before permanently deforming.
While the present disclosure has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the present disclosure is not limited to such disclosed embodiments. Rather, the present disclosure can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the present disclosure. Additionally, while various embodiments of the present disclosure have been described, it is to be understood that aspects of the present disclosure may include only some of the described embodiments. Accordingly, the present disclosure is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.

Claims

1. A burner comprising:

a burner tube formed at least partially from a first material having a plurality of openings, the plurality of openings being sized to allow a fluid, but not particles of debris contained within the fluid to flow there through; and

a flange extending outwardly from a portion of the burner tube and being receivable within an embossment formed in an adjacent component, wherein the flange is formed from a second material having a plurality of openings such that heat transfer between the flange and the adjacent component is limited.

2. The burner according to claim 1, wherein the flange is positioned at an outlet end of the burner tube.

3. The burner according to claim 1, wherein the first material having a plurality of openings and the second material having a plurality of openings are substantially identical.

4. The burner according to claim 3, wherein the flange is integrally formed with a portion of the burner tube.

5. The burner according to claim 1, wherein the first material having a plurality of openings and the second material having a plurality of openings are different.

6. The burner according to claim 5, wherein the flange is removably or fixedly coupled to a portion of the burner tube.

7. The burner according to claim 1, wherein when the flange is received within the embossment, the flange does not extend beyond a plane defined by the a surface of the adjacent component.

8. A burner assembly, comprising

a plurality of burners, each burner including a burner tube defining a burner axis, the burner tubes having an inlet, an outlet, and a flange extending outwardly from a portion of the burner tube; and

a partition plate arranged generally perpendicular to a horizontal plane containing the plurality of burner axes, the partition plate including a plurality of partition openings complementary to and arranged coaxially with the plurality of burners, wherein the flange of each burner is configured to mount to the partition plate, the flange being configured to limit heat transfer between the burner and the partition plate.

9. The burner assembly according to claim 8, further comprising a lock plate mounted positioned adjacent a surface of the partition plate, the lock plate being configured to engage a portion of at least one of the plurality of flanges to restrict movement of a burner away from the partition plate.

10. The burner assembly according to claim 8, wherein the partition plate includes a plurality of embossments, each of the plurality of flanges being receivable within one of the plurality of embossments.

11. The burner assembly according to claim 10, wherein a thickness of the flanges is less than a depth of the embossments.

12. The burner assembly according to claim 8, wherein the flange is arranged at an outlet end of each of the plurality of burner tubes.

13. The burner assembly according to claim 8, wherein the burner tube is formed from a first material having a plurality of openings, the plurality of openings being sized to allow a fluid, but not particles of debris contained within the fluid to flow there through.

14. The burner according to claim 13, wherein the flange is formed from a second material having a plurality of openings.

15. The burner according to claim 14, wherein the first material having a plurality of openings and the second material having a plurality of openings are substantially identical.

16. The burner according to claim 15, wherein the flange is integrally formed with a portion of the burner tube.

17. The burner according to claim 14, wherein the first material having a plurality of openings and the second material having a plurality of openings are different.

18. The burner according to claim 5, wherein the flange is removably or fixedly coupled to a portion of the burner tube.