JP2003532858A - NOX emission reduction burner assembly and method for reducing NOX content in combustion furnace exhaust gas - Google Patents

Abstract

SUMMARY A burner assembly (20) for a furnace or similar device has a firebox that defines a combustion zone (24). A first annular tile (36) wherein a burner assembly (20) defines a centrally located path for the flow of combustion air, and a second annular tile (38) concentric with the first annular tile. And The second annular tile (38) has an inner diameter greater than the outer diameter of the first annular tile (36), and the second annular tile (38) is disposed surrounding at least a portion of the first annular tile (36). A ring-shaped conduit is defined between the first and second annular tiles. The arrangement of the first and second annular tiles includes a flow of flue gas wherein the flow of combustion air along the path passes through a conduit for entrainment by the flow of combustion air.

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to large burners for industrial use. Such burners may be used to burn either gaseous fuels, including natural gas, or liquid fuels, including heavy oil. In particular, the present invention relates to a burner assembly of a low noise at low NO _X, the burner assembly to provide a structure for recycling directly flue gas from the internal Hishitsu.

[0002] the prior art today environmental problem, pollution minimal like of the NO _X noise at the minimum at and flue gas, effectively and economically operated, and supports the continued research of the burner. Previously, it has been stated that NO _x pollution may be reduced by returning flue gas to the combustion zone for recirculation. Various methods have been contemplated and / or developed to achieve this recirculation, including motor driven fans and eductor devices.
Generally, conventional burners utilize only the motive power of the combustion fuel to entrain the flue gas of the furnace. This conventional method has the following limitations: the gas is fast but has a low mass resulting in a low entrainment rate.

Further conventional methods have included the use of burners having a conduit internal structure for feeding the recycled flue gas back to the location where it is reintroduced into the combustion zone. This structural requirement results in a significant cost increase for the entire device. Therefore, there has been a need for a structural configuration that facilitates the recirculation of combustion exhaust gas.

SUMMARY OF THE INVENTION The present invention provides a novel burner assembly that addresses the problems and drawbacks of the prior art. In particular, the present invention provides a burner assembly that is simple in construction and facilitates the use of simple and effective motive power for flue gas recirculation. In the concept and principle according to the present invention, the use of combustion air for entraining combustion exhaust gas is very efficient as compared with the use of fuel gas, because of the significant difference in mass. It was confirmed. The mass of combustion air is typically 10 to 12 times that of gaseous fuel for combustion. The present invention also contemplates the simultaneous use of both combustion air and fuel gas to provide a large motive force for recirculating combustion gas.

The burner assembly according to the present invention finds application for mounting on a wall or floor or roof that defines a combustion zone in a furnace or firebox or the like. In the concept and principle according to the present invention, the burner assembly comprises a tile structure having a protrusion beyond the wall and into the combustion zone. The tile structure is
An air passageway formed to direct combustion air to the combustion zone and a recirculating combustion gas that is in communication with the air passageway and the area near the combustion zone when the burner assembly is mounted on the wall. (RFG conduit). In the present invention,
The RFG conduit is preferably located at the protrusion of the tile structure, thereby eliminating the need for mounting the RFG conduit within the furnace structure.

In a preferred form of the invention, the tile structure may include first and second tiles for ease of assembly, the RFG conduit being the first and second tiles. It may be defined between and. In this preferred embodiment of the invention, the second tile may be attached to the mounting structure of the first tile. Each of the first tile and the second tile may have an annular body segment and may be arranged as follows, the annular segment of the first tile surrounding the combustion air passage. Are disposed and the annular segment of the second tile may be disposed surrounding at least a portion of the annular segment of the first tile. Preferably, in the concept and principle according to the invention, the annular body segment of the first tile may have an outer surface and the annular body segment of the second tile has an inner surface. Alternatively, these surfaces may be arranged such that the RFG conduit is defined between the outer surface and the inner surface. Ideally, the annular body segment may be concentrically disposed on the outer surface, spaced radially inward from the inner surface, and the RFG conduit is substantially annular in shape. .

In a particularly preferred embodiment according to the invention, the second tile may have an annular end which engages the mounting structure of the first tile. In this preferred embodiment, the mounting structure extends radially outward from the outer surface of the annular segment of the first tile, at least one and preferably two ideally. It may include four circumferentially spaced shoulder members. In the most preferred embodiment, each of the plurality of shoulder members includes a notch formed to receive and mount the annular end. Such a structure facilitates positioning of the first and second tiles relative to each other and ensures concentricity.

In a further preferred embodiment, the burner assembly may comprise a burner nozzle for fluid fuel located in the air passage. In this embodiment, the burner nozzle for fluid fuel may be used to discharge a gaseous fuel, preferably natural gas or a particularly formulated combustible gas mixture into the combustion zone.
In the present invention, burner nozzles for fluid combustion are preferably used to supply pressurized gaseous fuel to various pressures within a predetermined range. Alternatively, the fluid fuel nozzle may be used to discharge a liquid fuel, preferably heavy oil, into the combustion zone.

The burner assembly is configured to discharge the fluid fuel through the conduit to discharge the RF fuel.
It may comprise at least one fluid fuel burner nozzle located near the inlet of the G 2 conduit. Additionally or alternatively, the burner assembly of the present invention may include a fluid fuel burner nozzle disposed on the outer peripheral surface of the annular body segment of the second tile.

The concepts and principles of the present invention may be applied to the burner assembly for use in mounting on a furnace having a firebox defining a combustion zone. The burner assembly defines a first annular tile defining a path for combustion air flow;
A second annular tile that is concentric with the first annular tile may be included. The second annular tile may have an inner diameter that is greater than the outer diameter of the first annular tile, the second annular tile being disposed around at least a portion of the first annular tile,
A ring-shaped RFG conduit may be defined between the first and second annular tiles. In an embodiment of the invention, the first and second annular tiles may also be used to position in the combustion zone the RFG conduit in direct communication with the flue gas in the area surrounding the combustion zone. Good. The burner assembly may preferably be adapted to direct the flow of flue gas through the conduit for the combustion air flowing along the path to be entrained by the flow of combustion air. . Ideally, the burner assembly may include a gas jet located near the inlet of the conduit that provides a flow of gas for mixing with the flue gas stream.

Further in concept and principle according to the invention, the invention provides an RFG inductive burner assembly. An RFG inductive burner assembly comprises a fuel nozzle arrangement arranged to introduce a flow of fluid fuel along a flow path into a combustion zone within a furnace interior of a furnace. Includes nozzle. The RFG inductive burner assembly includes a first tile structure having a central opening, the first tile structure enclosing the central opening surrounding the fuel nozzle; And is arranged to introduce an annular flow of combustion air through the fuel nozzle surrounding the fluid fuel flow path. The first tile structure has an outer peripheral surface that surrounds the central opening and extends around the first tile structure.

The RFG inductive burner assembly includes a second tile structure having a central passage. The second tile structure is preferably arranged such that the central passage surrounds at least a portion of the first tile structure. The second tile structure may have an inner surface extending around the central passageway, the inner surface facing the outer peripheral surface of the first tile structure and being spaced apart. May be. An annular space is defined between the outer peripheral surface of the first tile structure and the inner surface of the second tile structure. Preferably the first and second tile structures are arranged such that the annular space is in direct communication with the interior region of the firebox near the combustion zone when the burner is operably mounted to the furnace. To be done. In the concept and principle of the invention, the arrangement of the first and second tile structures preferably passes from the inner region through the annular space.
The flow of RFG may be directed by combustion air flowing through the central opening of the first tile structure. In this regard, it should be noted that the RFG-induced burner assembly of the present invention has been used to increase flue gas recirculation in conventional applications employing forced circulation air construction. Good.

In another embodiment, the present invention provides a low NO _x furnace containing an RFG induction burner assembly and a firebox having a combustion zone. In this form of the invention, the RFG induction burner assembly is operably attached to the low NO _x furnace to provide combustion air and fluid fuel to the firebox. In the present invention, the RFG induction burner assembly preferably includes a fuel nozzle arrangement including a nozzle arranged to introduce a flow of fluid fuel along a flow path into a combustion zone within a firebox of a furnace. And a first tile structure having a central opening and a second tile structure having a central passage. The first tile structure is arranged such that the central opening surrounds the fuel nozzle and introduces an annular flow of combustion air through the fuel nozzle surrounding the fluid fuel flow path. Good. The first tile structure may have an outer peripheral surface that surrounds the central opening and extends around the first tile structure. The second tile structure may be arranged such that the central passage surrounds at least a portion of the first tile structure. The second tile structure may have an inner surface extending around the central passage.
Preferably, in the concept and principle according to the present invention, the inner surface of the second tile structure faces the outer peripheral surface of the first tile structure and is spaced apart from the outer peripheral surface and the inner peripheral surface. The faces are preferably arranged so as to define an annular space between them.

The first and second tile structures may be arranged such that, when the burner is operably mounted, the annular space is in direct communication with an interior region of the firebox near the combustion zone. . The arrangement of the first and second tile structures is preferably guided by combustion air in which the flow of RFG from the interior through the annular space is flowing through the central opening of the first tile structure. It may be done. Further, the RFG induction burner assembly of the present invention may be used to increase flue gas recirculation in conventional applications employing forced circulation air construction.

Further in accordance with the concepts and principles of the present invention, NO _X in the furnace flue gas produced by burning combustion air and fluid fuel in the combustion zone of the furnace.
An efficient and effective method of reducing the content is provided. In this form of the invention, the method of reducing includes using the burner assembly described above to introduce RFG into the combustion zone.

In a further embodiment of the present invention, there is provided an efficient and effective method of reducing the NO _X content in the furnace flue gas. The method of reducing includes providing a flow of fluid fuel to a combustion zone in a firebox of the furnace, providing a flow of combustion air to the combustion zone, the fluid fuel and the combustion air. Directing an RFG flow directly from an area within the firebox near the combustion zone, utilizing the steps of combustion in the combustion zone, thereby creating a flame, and the motive force of the combustion air flow, The method may further include interacting the RFG stream with the fluid fuel and the combustion air within the combustion zone. As a result, in the heating furnace
NO _X generation and emission is reduced. Preferably, in the concepts and principles of the present invention, the combustion air flows along the longitudinal axis of the elongated burner assembly.

The present invention also provides a burner operating method for a gas-fired heating furnace having a firebox. In this embodiment of the invention, the method of operating the burner preferably comprises providing a flow of combustion air, providing a flow of fuel, and mixing the combustion air with the fuel. Combusting the mixture of the combustion air and the fuel in the combustion zone of the firebox, and utilizing the motive force of the combustion air to directly flow the combustion exhaust gas near the combustion zone. From a region in the firebox to a mixture of combustion air and fluid fuel, and thus a flame. Preferably, the method described above may further comprise the step of utilizing a motive force in the flow of the combustion gas fuel to further direct the flow of flue gas from the region near the combustion zone. Preferably, in this embodiment of the invention, the combustion air flows along the longitudinal axis of the elongated burner assembly.

One important aspect of the present invention involves the use of main air flowing axially through the burner assembly to entrain the RFG from the area directly at the periphery of the combustion zone. The axial entanglement device according to the invention makes it possible to provide a more uniform and homogeneous combustible gas mixture than it passes past the burner, whereby the usual stratification problems and the resulting flame insecurity. Qualitative is reduced. Advantages in the present invention over prior art burner assemblies include, but are not limited to, (1) shorter flame lengths (about 45.7 cm to 61 cm (1.5-2 ft) per unit MMBtuh). Against the unit
Approximately 15.2 cm to 33.5 cm (0.5 to 1.1 ft) per MMBtuh); (2) Wider turndown ratio (10: 1 to 3: 1); (3) Emergency around burner Low noise; (4) tiles are not subject to hotspots generated by combustion jets penetrating the tiles; (5) reduced cocking if not completely eliminated; (6) quasi-theoretical conditions To provide easy operation with significantly improved stability; (7) easy flame anchoring in the oxidizing atmosphere zone; (8) to provide a homogeneous mixture leading to a constant flame pattern. With that; (
9) prompt and a possible thermal both of the NO _X is reduced; (10) and that both the air and the combustion exhaust gas is utilized to entrainment of flue gas; (11) entrainment of flue gas is very efficient (12) The axial flame pattern reduces burner-to-burner interaction; (13) the burner assembly of the present invention is an RFG in forced air applications.
(14) The burner of the present invention is more efficient when used with a forced air design.

Detailed Description of Embodiments Referenced in the Present Invention In FIG. 1, a burner assembly in an embodiment according to the concept and principle of the present invention is indicated by reference numeral 20 as a whole. The assembly 20 is used to mount to a firebox wall 22, such as a furnace, as shown in particular. Wall 2
2 defines a combustion zone 24, which is disposed about and about the upper end 26 of the assembly 20 as shown in FIG. However, as will be appreciated by those skilled in the art of burners, the orientation of the assembly 20 is not critical and may be used in any position as well, so that the flame is directed upwards, downwards, It may be emitted horizontally or at an angle to the horizontal. Therefore,
Defining the end 26 as the upper end is for reference only. Further, it will be appreciated that the principles and concepts of the present invention are not limited to use with circular burner tiles. In this regard, the principles and concepts of the present invention may be applied to burners having rectangular burner tiles, flat flame burners, and axisymmetric burners.

The burner assembly 20 includes conventional accessories required for operation, which include an air inlet 28 used to connect to a combustion air source, an air chamber 30, and a fuel source. And a manifold device 32 used to distribute fuel to the individual burner nozzles of the burner assembly. These devices are conventional and known to those skilled in the art of burners. As shown in FIGS. 1 and 7, the device 20 may include a mounting flange 33 on the wall 22. Flange 33 may be attached with conventional bolt (stud) and nut devices (FIG. 4).

The burner assembly 20 particularly directs flue gas flow from a region 34 proximate to the combustion zone 24 and further circulates the flue gas to lean the mixture of air and fuel that burns in the combustion zone 24. Used to These circulating flue gas is often expressed as RFG (or FGR), following it is a known phenomenon, RFG is the generation of mixed are the NO _X in the combustion zone and fuel in a combustion zone Decrease.

As shown in FIG. 1 in the present invention, the assembly 20 includes a tile structure 36 having a portion 38 that projects beyond the wall surface 22 and into the combustion zone 24.
That is, the portion 38 of the tile structure 36 projects into and is located substantially within the combustion zone 24. The tile structure 36 is a first lower upstream inner tile structure 40.
And a second upper downstream outer tile structure 42. In particular, as shown in FIG. 7, the tile 42 is attached to the mounting structure 44 of the tile 40.

In the preferred embodiment of the invention, best shown in FIGS. 7, 8 and 9, a tile 40 surrounds a central opening, a generally annular body segment 46, a base 50, and a plurality of bases 50. The shoulder members 52, which are preferably substantially identical, are evenly spaced about the outer circumference of the body segment 46. As shown, the assembly includes four shoulder members 52, but it will be understood by those skilled in the art that the assembly is adapted to use only three shoulder members 52. As shown, the shoulder member 52 extends radially outwardly from the outer peripheral surface 54 of the annular body segment 46 to provide the mounting structure 44 for the tile 42 described above. To this end, the shoulder member 52 includes a notch 56 formed to receive and mount the annular end 58 of the tile 42. That is, when the tiles 40 and 42 are assembled into the tile structure 36, the ends 58 of the tiles 42 are notched 5
6 engages with a generally horizontal ledge 60, which corresponds to 6. End 58
The notch 56 being received and installed is shown in FIG.

As will be appreciated, the surface 54 extends around the tile 40 and surrounds the opening 48. The tiles 40, 42 of the tile structure 36 may be connected together using known conventional mounting equipment. If the tile structure 36 is mounted to the bottom wall of the furnace, the tile may simply be placed on the mounting structure 44.
On the other hand, if the tile structure 36 is mounted elsewhere, the tile 42 may be connected to the tile 40 using elongated studs, which studs are cast into the tile 42 at locations corresponding to the locations of the notches 56. It is embedded. The stud receiving holes may be adapted to extend downwardly from the notch 56 to the flange 33 through the shoulder member 52, such that the nut may extend through the elongated stud to the tile 40,
It may be used to attach 42 to flange 33.

In the preferred embodiment of the invention shown in FIGS. 3, 7 and 10, the tile 4
2 has an annular body segment 62 surrounding a central opening 64.
The inner diameter of the tile 42 is larger than the outer diameter of the tile 40. Therefore, as shown in FIG.
When the tile 42 is attached to the tile 40, the annular body segment 62 of the tile 42 surrounds at least a portion of the annular body segment 46 of the tile 40. In particular, the lower end 58 of the annular body segment 62 surrounds the frustoconical upper portion 68 of the annular body segment 46. Therefore, it is understood that the annular body segments 46 and 62 define the frustoconical upper portion 6 of the tile 40 as follows.
8 are arranged concentrically with the annular outer surface 70 of the tile 4,
The second lower end portion 58 is spaced from the annular inner surface 72 toward the inner side in the radial direction.

When mounting the tile 42 to the tile 40 in the operating condition shown in FIGS. 3 and 7,
It is understood that the central opening 48 of the tile 40, together with the central opening 64 of the tile 42, defines a passageway 74 defining a path 76 for introducing combustion air from the air chamber 30 into the combustion zone 24. Has become. As can be seen in FIGS. 3 and 7, the passageways 74 define annular body segments 46 and 62 of the tiles 40 and 42, respectively.
And is surrounded by an annular surface 72 (not shown in FIG. 3) that also extends around the passage.

As mentioned above, the annular outer surface 70 of the frustoconical upper portion 68 of the tile 40 is radially inwardly spaced from the annular inner surface 72 of the lower end portion 58 of the tile 42. Thus, surfaces 70 and 72 are spaced apart and face each other. Face 70
An annular space 78 (see FIG. 3) between and 72 provides an annular or ring shaped RFG conduit 80 which communicates the air passage 74 with the region 34 adjacent the combustion zone 24. is doing. Accordingly, the RFG conduit 80 defined between the upper tile 40 and the lower tile 42 is in direct communication with the flue gas in the region 34 surrounding the combustion zone 24 and the combustion air flowing along the path 76. , for the entrainment by the combustion air to the combustion exhaust gas, induced through the conduit 80 from the area 34, further dilute the gas burned in the combustion zone 24 in order to reduce the generation of the NO _X and cooling be able to.

That is, the tiles 40 and 42 are arranged as follows, and the flow of the RFG from the region 34 through the annular space 78 is along the passage 74 and the openings 48 and 64.
It is induced by the action of combustion air flowing through. Combustion air flowing through the downstream end 81 of the conduit 80 produces a motive force that induces a flow of RFG through the conduit 80. Thus, the tile arrangement provides a very similar effect to an eductor or ejector. That is, the mass of the combustion air flowing in the direction of the arrow 76 is
The RFG wraps directly from region 34 into the interior of the firebox surrounding the tile assembly 20 according to the present invention. RFG is flowing from region 34, through ring conduit 80, through conduit end 81, in the direction of arrow 85, where end 81
At, the air is entrained by the combustion air flowing along the path 76. Therefore, the mass of the combustion air flowing in the direction of the arrow 76 provides the driving force, so that the combustion exhaust gas is entrained from the region 34 along the path of the arrow 85, and is further delivered to the outlet end portion 83 of the gas nozzle 82. In section 83, the combustion exhaust gas is diffused and mixed with the combustion mixture, thereby delaying the reaction rate of combustion and oxygen from the combustion air.

In the present invention, the downstream tiles 42 are arranged around the upstream tiles 40 to form a ring-shaped conduit 80 which is open to the furnace gas inside the heating furnace. ing. These furnace top gases pass through the center of tile 42
6 is capable of interacting with the air flowing along it, producing a confluent flow exiting the tile system about 118% of the inlet air volume (volume). This increased top gas is blown around the flame inside the combustion zone 24, reducing the uniform and even diffusion of air into the main flame.

It should be noted in this regard that the tile 40 has four shoulder members 52, but is actually desired and / or desired in a given application. Alternatively, the number required may vary based on, for example, the overall size of the tile, the orientation of the assembly, the weight of tile 42 and / or the flow passage area required for passageways 74 and conduits 80.

In the preferred embodiment of the present invention shown in FIGS. 1-10, burner assembly 20 may include burner nozzles for first, second and third fluid fuels.
The first nozzle 82, shown primarily in FIGS. 3 and 7, is surrounded by the tiles 40 and 42 and is also located approximately in the center of the passage 74 so that an annular flow of combustion air is provided in the central opening. It passes directly through the nozzle 82 at 64. Therefore, the combustion air initially flows in an enclosed state with respect to the fuel flow flowing out of the nozzle 82. Although the nozzle 82 as shown is specifically used to deliver gaseous fuel to the combustion zone, it should be understood that in the concept and principle of the invention, the nozzle 82 is a liquid. Either fuel, such as heavy oil or gaseous fuel, such as natural gas, is used to deliver along a path that is generally parallel to the path 76 to the combustion zone.

In a preferred embodiment of the invention, burner assembly 20 may include a plurality of, preferably four, second burner nozzles or gas jets 84. In particular, these nozzles 84 shown in FIGS.
Is located near the inlet 86 of the fuel cell to mix the fuel gas with the RFG. In addition, the gas emitted from nozzle 84 provides a driving force to further induce RFG flow from region 34. As will be appreciated by those skilled in the art of burners, the number of nozzles 84 is not critical and the number of nozzles may vary from zero to eight or more depending on the given application. However, if the assembly includes multiple second nozzles, the second nozzles should be evenly spaced around the outer perimeter of the annular tile segment 46 as shown.

Burner assembly 20 may include a plurality of, preferably four, third burners or gas jets 88. In particular, the nozzle 8 shown in FIGS.
8 may preferably be attached to respective channels 90 provided on the outer perimeter 92 of the annular tile segment 62. Preferably, the shoulder member 52 may include an end surface 94 that provides support for a tube 96 that supplies fuel to the nozzle 88. As will be appreciated by those skilled in the art of burners, the number of nozzles 88 is not critical and the number of nozzles may vary from zero to eight or more depending on the given application. However, if the assembly includes multiple third nozzles, the second nozzles should be evenly spaced around the outer perimeter 92 of the annular tile segment 62 as shown.

Detailed Example A detailed example of the operation of the heating furnace using the embodiment of the present invention shown in FIGS. 1 to 10 is as follows.

The burner burns at 8.0 MMBtuh. Excess air is 15%. Heating furnace humidity is about 8
15.6 ° C (1500 ° F). Burner differential pressure is about _{7.6mmH 2 O (0.3 in H 2} O)
. The damper for the burner is fully open. Combustion gas is 100% natural gas. Single central fuel nozzle type. The result is as follows: 3% oxygen, 0ppm CO and about 2
And NO _X of 0~35ppm was measured.

In the above description and detailed examples, the fuel has been described simply as fuel gas or natural gas. A noteworthy the following points in this respect, the burner according to the present invention, release of the NO _X even when burning conventional liquid fuel containing other fluid fuel for example oil or other gaseous fuel mixture Can be effectively used to reduce It should also be noted that current equipment can be modified to use the principles and concepts of the present invention.

As mentioned above, the burner assembly according to the present invention includes first, second and third burners. An alternative embodiment is shown schematically in Figures 11-16. In each case, the tile structure including the schematically illustrated concentric tiles may be the same as tiles 40 and 42 described above. The burner assembly shown in FIG. 11 may include only a single centrally located burner nozzle. The burner assembly shown in FIG. 12 may include two or more burner nozzles located near the outer perimeter surface of the upstream tile proximate the RFG induction conduit inlet. The burner assembly shown in FIG. 13 may include two or more burner nozzles located on the inner surface of the central opening in the upstream tile near the RFG induction conduit. The burner assembly shown in FIG. 14 may include a centrally located first nozzle and two or more burner nozzles located on the outer perimeter surface of the downstream tile. The burner assembly shown in FIG. 15 may include a single centrally located first burner nozzle with a premixer and a conventional swirler mechanism. The burner assembly shown in FIG. 16 may be arranged as described above with reference to FIGS. 1-10, but in this case the central burner nozzle is used specifically for delivering liquid fuel. In each case
RFG flow from region 34 through conduit 80 may be induced by combustion air flowing along path 76 through conduit end 81.

An alternative embodiment of the burner apparatus according to the concepts and principles of the present invention is shown in FIG.
21 and the device is generally designated by the numeral 120. The burner device 120 has the same arrangement as the burner device 20, except that the upper tile 142 is placed on the lower tile 140. This is tile 140 and 1
The arrangement of the annular space 178 defined between the inner space 42 and the inner space 42 is changed.

17-21, the lower tile 140 includes a plurality of shoulder members 152 that project radially outwardly from the outer peripheral surface 154 of the annular body segment 146. At the same time, the upper surface 153 of the member 152 is the mounting structure 1 for the tile 142.
44 are offered. For this purpose, the top tile 142 comprises a plurality of downwardly projecting legs 159. In the present invention, the leg 15 of the upper tile 142
The number of nine matches the number of members 152 of the lower tile 140 and the legs 159 are arranged to engage the upper surface 153 when the tile is assembled. In this arrangement, the lower end portion 158 of the upper tile 142 is aligned with the upper end portion 16 of the lower tile 140.
Vertically spaced from 1. Such space provides an arrangement for the annular space 178 that is different than the arrangement for the annular space 78 of the burner assembly 20. This space also changes the layout of the path 185 for the flow of flue gas from the interior of the furnace to the central passage 174 within the tiles 140, 142. Of course, such flow is induced by the combustion air flow along path 176, as well as by the combustion gas flow from nozzle 184. The tiles 142 may be extended by conventional means such as legs 159 through stand receiving holes that extend through the shoulder members 152.
The tiles 140 may be attached with studs extending downwardly from.

It can be seen in FIG. 19 that channel 190 is angularly offset with respect to shoulder member 152, but channel 90 in burner apparatus 20 is not angularly offset with respect to shoulder member 52. In the concept and principle according to the present invention, the channel 190 is preferably offset at an angle of 45 ° with respect to the shoulder member 152. This angular offset positions the nozzle 184 in a position that provides the minimum structure for producing fuel flow from the nozzle 184 to the annular space 178.

In an alternative embodiment of the burner apparatus according to the concepts and principles of the present invention shown in FIG. 22, the apparatus is generally designated by the numeral 220. Burner device 220 is substantially identical to burner device 120, except for the placement of burner nozzles 284 and the radial dimensions of shoulder members 252. The device in FIG. 22 facilitates the use of smaller diameter burners than the burner device 120.

The burner device of the present invention has low NO _X emission, low noise, RFG air entrainment, prompt NO _X mitigation, simple structure, short flame shape, and large turndown ratio. And achieves high stability and low CO emission. The flow of RFG is
It is guided without the use of mechanical means such as a blower, by using combustion air instead of fuel gas as the driving force for the RFG entrainment. In addition, the device has a second gas tip located behind the burner tile,
Jet noise is insulated from the outside of the burner. Further diffusion of direct RFG from internal heating furnace prior to combustion to the gas jet has brought a reduction in prompt NO _X. The device is simple, provides a reduction in manufacturing costs and provides easy operation.

An important aspect in the [0043] present invention, in order to reduce the NO _X release and to facilitate the homogeneity of the mixture, in order to encourage the mixing of the combustion gases and the RFG and the combustion air,
It is to provide a non-powered means of flue gas. The burner system is based, at least in part, on the important concept of using an axially flowing mass of combustion air, which involves entraining the RFG from the furnace and introducing a sufficient amount of fuel gas into the RFG. Mix and ensure that the mixture is combustible. As previously mentioned, the present invention contemplates using both the mass of combustion air flowing axially and the mass of fuel provided via a gas jet, involving the RFG from the furnace, And RFG is mixed with the incoming fuel.

The impedance of the combustion produced by the flue gas flowing into the nozzle device according to the invention lowers the flame temperature and thus prevents the formation and emission of NO _X. In previous designs of the invention, a small amount of flue gas was entrained by the individual gas jets that suck the flue gas into the tile block. The old design proved to be clearly ineffective against flue gas stratification that results in long flames and burner instability. In the present invention, the energy of a large amount of flowing combustion air is utilized, resulting in a large amount of flue gas entrainment, resulting in a more effective mixing of the gas jet and flame. There is. Here, the important points of interest are as follows, and the induction of the flue gas into the combustion exhaust gas air is performed in the heating furnace space, and the flue gas does not have to be returned to the burner body unlike the conventional burner device.

In the simplest configuration of the burner, the flame is to ignite and stabilize in the oxidizing atmosphere zone within the first tile. Flame follicle end surface spreads rapidly into sufficient second section of the flue gas, are avoided formation and release of the NO _X in the second section. The flame bladder end face is consistently stable, as well as being reliably stabilized and formed in the first (oxidizing atmosphere) zone of the first tile section, even when flowing into the second flue gas lean zone. There is no loss of sex. Rapid without instability, diffusion and quenching maintain short flame lengths and large turndown ratios. Flame length is usually about 3 per 1055 MJ (million BTU) burning rate (fuel dependent)
A turndown ratio of 3.5 cm (1.1 ft) or less and a normal natural ventilation low NO _X burner of the order of 10: 1 is easily achieved. CO emissions are generally zero, depending on the furnace temperature.

Burner arrangements other than those shown in the figures in the present invention utilize staged fuel utilizing gas guns or with a main riser inserted in a ring conduit for supplemental NO _x reduction. (Staged fuel) is included. If a first annular tile is used as shown, the riser is isolated from the exterior of the burner by the first tile,
Jet noise emitted to the outside by the burner is greatly reduced.
The main riser is fully lowered in the ring line and the gas jet has sufficient time to entrain pure flue gas before entering the oxidizing atmosphere zone. Premixing of the combustion gas and the combustion exhaust gas, lowering the reaction rate of the combustion gases, thereby reducing the formation of incidental the NO _X. Once the gas jet starts to burn, the combustion exhaust gas increases in the atmosphere, and the combustion exhaust gas is constantly entrained by the combustion air.
Since the prompt NO _x and the thermal NO _x are greatly reduced, the overall effect is that the NO _x is greatly reduced. The generally simple burner, which is stable in the oxidizing atmosphere zone, makes the burner device of the present invention a significant advance over the prior art.

[Brief description of drawings]

FIG. 1 is a side view of a burner assembly in an embodiment according to the concepts and principles of the present invention.

[Fig. 2]   FIG. 2 is a plan view of the lower end surface of the burner in FIG. 1 seen from below.

[Figure 3]   FIG. 3 is a plan view of the upper end surface of the burner in FIG. 1 seen from above.

FIG. 4 is an enlarged detail view showing the portion of the burner assembly in FIG. 2 enclosed by circle 4;

5 is an enlarged detail view showing a portion of the burner assembly in FIG. 3 surrounded by a circle 5;

FIG. 6 is an enlarged detail view showing a portion of the burner assembly in FIG. 3 surrounded by a circle 6;

7 is an enlarged view, partially in section, showing the tile structure of the burner assembly in FIG.

FIG. 8 is a plan view of a lower (upstream of the flow) tile of the tile structure in FIG.

[Figure 9]   9 is a side view of the lower tile in FIG.

10 is a side view, partially in section, showing the top (downstream of the flow) tile of the tile structure in FIG. 7.

FIG. 11 is a schematic side view showing an alternative first embodiment of a burner assembly according to the present invention.

FIG. 12 is a schematic side view showing an alternative second embodiment of a burner assembly according to the present invention.

FIG. 13 is a schematic side view showing an alternative third embodiment of a burner assembly according to the present invention.

FIG. 14 is a schematic side view showing an alternative fourth embodiment of a burner assembly according to the present invention.

FIG. 15 is a schematic side view showing an alternative fifth embodiment of a burner assembly according to the present invention.

FIG. 16 is a schematic side view showing an alternative sixth embodiment of a burner assembly according to the present invention.

FIG. 17 is a side view, partially in section, showing an alternative configuration of the burner assembly in embodiments according to the concepts and principles of the present invention.

FIG. 18   FIG. 18 is a plan view of the burner in FIG.

FIG. 19   19 is a cross-sectional view taken along the line 19-19 in FIG.

FIG. 20   20 is a cross-sectional view taken along the line 20-20 in FIG.

FIG. 21   21 is a cross-sectional view taken along line 21-21 in FIG.

FIG. 22 is a side view, partially in section, showing another alternative form of burner assembly in an embodiment in accordance with the concepts and principles of the present invention.

[Procedure amendment]

[Submission Date] March 12, 2002 (2002.3.12)

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Contents of correction]

[Claims]

3. The first tile and the second tile each have an annular body segment, the annular segment of the first tile being disposed around the air passage. The annular body segment has an outer surface and the annular body segment of the second tile has an inner surface, the RFG conduit being defined between the outer surface and the inner surface. The burner assembly according to claim 2, wherein:

4. The burner assembly of claim 3 , wherein the annular body segment is concentrically disposed on the outer surface radially inwardly spaced from the inner surface.

Wherein where the RFG conduit is substantially annular in shape, the burner assembly according to any one of claims 1-4.

6. at which said second tile is attached to said first tile, a burner assembly according to any one of claims 1 to 5.

7. wherein the second tile, as having an annular end portion which engages the structural member for mounting said first tile this, the burner assembly according to any one of claims 3-5 .

8. The at least one shoulder member having a generally annular arrangement with the outer surface and the inner surface, the mounting structure extending radially outward from the outer surface. The burner assembly of claim 7 , wherein:

9. The mounting structure for the, from the outer surface are extended radially outward, where containing a shoulder member spaced at least two circumferentially claim 7 or 8 Burner assembly described in.

10. The mounting structure of any of claims 7-9, wherein the mounting structure includes four circumferentially spaced, radially extending shoulder members. Burner assembly.

11. shoulder member or each of the shoulder member, where that contains the notch formed to attach to receiving the annular end, according to any one of claims 8-10 burner assembly.

12. The burner assembly of claim 6 wherein the second tile has a plurality of spaced legs that engage the mounting structure of the first tile.

13. constitute a plurality of shoulder members the mounting structure for the angularly spaced, at which each of the leg is engaged with the respective shoulder member, the burner assembly of claim 12 .

14. air is provided with a burner nozzle for a fluid fuel disposed in the path, a burner assembly according to any one of claims 1 to 13.

15. burner nozzle fluid fuel, where that is used to eject the gaseous fuel to the combustion zone, the burner assembly of claim 14.

16. The burner assembly of claim 15 , wherein the gaseous fuel is natural gas.

17. The burner assembly of claim 14 , wherein the fluid fuel burner nozzle is used to deliver fluid fuel to the combustion zone.

18. where the liquid fuel is heavy fuel oil, the burner assembly of claim 17.

19. A fluid fuel to discharge through the RFG conduit, the RFG
19. A burner assembly as claimed in any one of the preceding claims, comprising at least one fluid fuel burner nozzle located near the inlet of the conduit.

The 20. fluid fuel to discharge through the RFG conduit, the RFG disposed near the inlet of the conduit, have ingredients Bei at least one fluid fuel burner nozzle, further fluid fuel use the burner nozzle, where that angles to offset for each of the shoulder member, bar toner assembly according to any one of claims 8-10.

21. The burner assembly includes a plurality of burner nozzle, where each of said burner nozzles are angularly offset with respect to each of the shoulder member, according to claim 20 burner assembly .

22. said second tile of the annular body segments burner assembly according to any one of claims 3 to 21 which comprises a burner nozzle for a fluid fuel disposed on the outer peripheral surface of the.

To pivot the combustion air and fluid fuel 23. The inside air passage and comprises a swirler attached to the air passage, wherein one item of claims 1 to 22 Neu deviation Burner assembly.

24. A burner assembly according to any one of claims 2 to 23, wherein the first and second tile structures are substantially circular and are concentrically mounted.

25. The burner assembly of any one of claims 2-24, wherein the first and second tile structures are substantially rectangular.

26. A burner assembly for a furnace having a firebox which defines a combustion zone, the heating furnace burners assembly have provided a first annular tile and a second annular tile: Part No. An annular tile defining a path for combustion air flow; the second annular tile being concentric with the first annular tile and the second annular tile having an inner diameter greater than the outer diameter of the first annular tile. The second annular tile is disposed around the track and a ring-shaped conduit is defined between the first and second annular tiles, the first and second annular tiles comprising: The arrangement of the first and second annular tiles is used to position in the combustion zone the conduit that is in direct communication with the flue gas surrounding the combustion zone, the arrangement of the first and second annular tiles being the combustion air flowing along the path. Is entrained by the flow of the combustion air Directing the flow of the flue gas through the conduit for a furnace burner assembly.

27. to provide a flow of gas for mixing with the flue gas flow, where that contains the arrangement gas jet near the entrance of the conduit, the furnace burner according to claim 2 6 assembly.

28. An RFG inductive burner assembly comprising a fuel nozzle arrangement, a first tile structure and a second tile structure, the fuel nozzle arrangement comprising a flow of fluid fuel along a flow path. A first tile structure having a central opening, the first tile structure having a central opening, the nozzle being arranged for introducing into a combustion zone within a fire chamber of a heating furnace; Are arranged to surround the fuel nozzle and to introduce combustion air passing through the fuel nozzle surrounding the flow passage, the first tile structure surrounding the central opening An outer peripheral surface extending around the tile structure; the second tile structure having a central passageway such that the central passageway surrounds the flow passage. And the second tile structure is located in the central passage. Having an inner surface extending around a circumference of the first tile structure, the inner surface facing the outer peripheral surface of the first tile structure and spaced apart, the outer peripheral surface and the inner surface defining an annular space therebetween. And the first and second tile structures are such that when the burner is operably mounted to the furnace, the annular space is in direct communication with an interior region of the firebox near the combustion zone. The arrangement of the first and second tile structures is such that the flow of RFG from the interior region through the annular space is flowing through the central opening of the first tile structure. RFG induction burner assembly.

29. The low NO _X furnace comprising a firebox to provide RFG induction burner assembly and the combustion zone, the RFG induction burner assembly, supplying the combustion air and fluid fuel該火chamber An RFG induction burner assembly operably attached to the low NO _x furnace for providing a fuel nozzle device, a first tile structure and a second tile structure. The fuel nozzle arrangement includes a nozzle arranged to introduce a flow of fluid fuel along a flow path into a combustion zone within a fire chamber of a furnace; the first tile structure having a central opening. A portion of the first tile structure is arranged to introduce combustion air through the fuel nozzle, the central opening surrounding the fuel nozzle and surrounding the flow passage, The first tile structure is Having an outer peripheral surface surrounding the central opening and extending around the first tile structure; the second tile structure having a central passage, the second tile structure having the central A passage is disposed to surround the outer peripheral surface of the first tile structure, the second tile structure having an inner surface extending around the central passage, the inner surface being the first tile structure. Facing the outer peripheral surface of and spaced apart, the outer peripheral surface and the inner surface being arranged to define an annular space therebetween, and the first and second tile structures include the annular space. Are arranged so as to be in direct communication with the interior region of the firebox near the combustion zone, and the arrangement of the first and second tile structures is such that the flow of RFG from the interior through the annular space is the first To be guided by combustion air flowing through the central opening of the tile structure RFG induction burner assembly.

30. Efficient and effective reduction method of the NO _X content in the furnace flue gas: stage and providing a flow of fluid fuel into the combustion zone in the firebox of the heating furnace; flow of combustion air To the combustion zone; burning the fluid fuel and the combustion air in the combustion zone, thereby creating a flame; utilizing the motive force of the flow of the combustion air to Directing a flow of RFG directly from a region within the firebox near the combustion zone, and further interacting the flow of RFG with the fluid fuel and the combustion air within the combustion zone. And a NO _x reduction method by which the generation and release of NO _x in the heating furnace is reduced.

31. A burner operating method for a gas-combustion heating furnace having a firebox:; and providing a flow of fuel; step and providing a flow of combustion air and combustion air and fuel Mixing; combusting a mixture of the combustion air and the fuel in a combustion zone of the firebox; utilizing the motive force of the combustion air to directly flow the flue gas. Directing a flame of the mixture from an area in the firebox near a combustion zone;

32. The method of operating a burner of claim 30 or 31 , wherein the combustion air flows along the longitudinal axis of the elongated burner assembly.

33. A step of inducing the flow of flue gas from the region is, where utilizing driving force in the flow of combustion gas fuel burner operating method of claim 30 or 31.

34. An efficient and effective method for reducing the NO _X content in a heating furnace combustion exhaust gas generated by burning combustion air and a fluid fuel in a combustion zone of a heating furnace is a method for burning RFG. to introduce the area, NO _X reduction method includes the step of using the burner assembly of claim 1 to 29, whichever is one wherein.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0018

[Correction method] Change

[Contents of correction]

One important aspect of the present invention involves the use of main air flowing axially through the burner assembly to entrain the RFG from the area directly at the periphery of the combustion zone. The axial entanglement device according to the invention makes it possible to provide a more uniform and homogeneous combustible gas mixture than it passes past the burner, whereby the usual stratification problems and the resulting flame insecurity. Qualitative is reduced. The advantages of the present invention over prior art burner assemblies include, but are not limited to, (1) shorter flame lengths ( about 45.7 cm to 61 cm (1 ) per flame length of about 1055 MJh (10 ⁶ Btuh). .5-
2ft) for about 1055MJh (10 ⁶ Btuh) per about 15.2cm~33.5cm (0.
5 to 1.1 ft)); and (2) a wider turndown ratio (3: 1 to 10:10).
(1) and; (3) very low noise around the burner; (4) the tile is not subject to hotspots created by the burning jets penetrating the tile; (
5) a tendency to reduce cocking even if it does not disappear completely; (6) easy operation with significantly improved stability in the quasi-theoretical state; (7) flame anchoring in an oxidizing atmosphere area. it is easy; constant (8) guiding the flame pattern and to provide a homogeneous mixture; (9) prompt and a possible thermal both of the NO _X is reduced; (10) air and combustion exhaust gas Both of them are used for entrainment of flue gas; (11) Entrainment of flue gas is very efficient; (1
2) The axial flame pattern is to reduce burner-to-burner interaction; (13) The burner assembly in the present invention is an RFG in forced air applications.
(14) The burner of the present invention is more efficient when used with a forced air design.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0035

[Correction method] Change

[Contents of correction]

The burner is burned at about 8440 MJh (8.0 × 10 ⁶ Btuh) . 1 for excess air
5%. Heating furnace humidity is about 815.6 ° C (1500 ° F). Burner differential pressure is about 7.6
mmH ₂ O (0.3 in H ₂ O). The damper for the burner is fully open. Combustion gas is 100% natural gas. Single central fuel nozzle type. The results were as follows, and 3% oxygen, 0 ppm CO, and about 20 to 35 ppm NO _X were measured in the combustion exhaust gas.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0045

[Correction method] Change

[Contents of correction]

In the simplest configuration of the burner, the flame is to ignite and stabilize in the oxidizing atmosphere zone within the first tile. Flame follicle end surface spreads rapidly into sufficient second section of the flue gas, are avoided formation and release of the NO _X in the second section. The flame bladder end face is consistently stable, as well as being reliably stabilized and formed in the first (oxidizing atmosphere) zone of the first tile section, even when flowing into the second flue gas lean zone. There is no loss of sex. Rapid without instability, diffusion and quenching maintain short flame lengths and large turndown ratios. The flame length is usually about 33.5 cm (1.1 ft) or less per burning rate (depending on the fuel) about 1055 MJ (10 ⁶ BTU) , and normal natural ventilation low NO _x.
Turndown ratios on the burner on the order of 10: 1 are easily achieved.
CO emissions are generally zero, depending on the furnace temperature.

─────────────────────────────────────────────────── ─── Continued front page    (81) Designated countries EP (AT, BE, CH, CY, DE, DK, ES, FI, FR, GB, GR, IE, I T, LU, MC, NL, PT, SE, TR), OA (BF , BJ, CF, CG, CI, CM, GA, GN, GW, ML, MR, NE, SN, TD, TG), AP (GH, G M, KE, LS, MW, MZ, SD, SL, SZ, TZ , UG, ZW), EA (AM, AZ, BY, KG, KZ, MD, RU, TJ, TM), AE, AG, AL, AM, AT, AU, AZ, BA, BB, BG, BR, BY, B Z, CA, CH, CN, CR, CU, CZ, DE, DK , DM, DZ, EE, ES, FI, GB, GD, GE, GH, GM, HR, HU, ID, IL, IN, IS, J P, KE, KG, KP, KR, KZ, LC, LK, LR , LS, LT, LU, LV, MA, MD, MG, MK, MN, MW, MX, MZ, NO, NZ, PL, PT, R O, RU, SD, SE, SG, SI, SK, SL, TJ , TM, TR, TT, TZ, UA, UG, UZ, VN, YU, ZA, ZW (72) Inventor Schnapper, Carroll A.             74105, Oklahoma, United States             Ursa, East 35th             Treat 1634 F-term (reference) 3K019 AA06 BA03 BA06 BD06                 3K065 TA01 TC03 TD04 TD05 TH01                       TJ06 TL04 TP02

Claims (45)

[Claims] 1. A burner assembly used to mount a combustion zone to a wall defining a combustion zone, the burner assembly comprising a tile structure having a protrusion beyond the wall and into the combustion zone. The tile structure has an air passage formed to guide combustion air to the combustion zone, and the burner assembly is attached to the wall surface, the air passage and the combustion zone vicinity area. A burner assembly, wherein the burner assembly is an RFG conduit in communication with the RFG conduit, the RFG conduit being located at the protrusion of the tile structure. 2. The tile structure includes a first tile and a second tile,
The burner assembly of claim 1, wherein the RFG conduit is defined between the first tile and the second tile. 3. The burner assembly of claim 2, wherein the second tile is attached to the mounting structure of the first tile. 4. The first tile and the second tile each have an annular body segment, the annular segment of the first tile being disposed around the air passage. The annular body segment has an outer surface and the annular body segment of the second tile has an inner surface, the RFG conduit being defined between the outer surface and the inner surface. The burner assembly according to claim 2, wherein: 5. The burner assembly of claim 4, wherein the annular body segment is concentrically disposed on the outer surface radially inwardly spaced from the inner surface. 6. The burner assembly of claim 5, wherein the RFG conduit is substantially annular in shape. 7. The burner assembly of claim 5, wherein the second tile is attached to the first tile. 8. The burner assembly of claim 7, wherein the second tile has an annular end that engages the mounting structure of the first tile. 9. The at least one shoulder member having a generally annular arrangement with the outer surface and the inner surface, the mounting structure extending radially outward from the outer surface. The burner assembly of claim 8, wherein the burner assembly is present. 10. The mounting structure of claim 9, wherein the mounting structure includes at least two circumferentially spaced shoulder members extending radially outward from the outer surface. Burner assembly. 11. The burner assembly of claim 9, wherein the mounting structure includes four circumferentially spaced, radially extending shoulder members. 12. The burner assembly of claim 9, wherein the at least one shoulder member includes a notch formed to receive and mount the annular end. 13. The burner assembly of claim 10, wherein each of the plurality of shoulder members includes a notch formed to receive and mount the annular end. 14. The burner assembly of claim 11, wherein each of the plurality of shoulder members includes a notch formed to receive and mount the annular end. 15. The burner assembly of claim 5, comprising a burner nozzle for fluid fuel located in the air passage. 16. The burner assembly of claim 15 wherein said fluid fuel burner nozzle is used to deliver gaseous fuel to said combustion zone. 17. The burner assembly of claim 16 wherein the gaseous fuel is natural gas. 18. The burner assembly of claim 15, wherein the fluid fuel burner nozzle is used to deliver fluid fuel to the combustion zone. 19. The burner assembly of claim 18, wherein the liquid fuel is heavy oil. 20. The RFG for discharging the fluid fuel through the RFG conduit.
The burner assembly of claim 5, comprising at least one fluid fuel burner nozzle located near the inlet of the conduit. 21. The burner assembly of claim 5 including a fluid fuel burner nozzle disposed on an outer peripheral surface of the annular body segment of the second tile. 22. A burner assembly for a furnace having a firebox defining a combustion zone, the burner assembly comprising a first annular tile and a second annular tile: An annular tile defining a path for combustion air flow; the second annular tile being concentric with the first annular tile and the second annular tile having an inner diameter greater than the outer diameter of the first annular tile. The second annular tile is disposed around the track and a ring-shaped conduit is defined between the first and second annular tiles, the first and second annular tiles comprising: The arrangement of the first and second annular tiles is used to position in the combustion zone the conduit that is in direct communication with the flue gas surrounding the combustion zone, the arrangement of the first and second annular tiles being the combustion air flowing along the path. Is entrained by the flow of the combustion air To direct the flow of flue gas through the conduit of; at the furnace burner assembly. 23. The method of claim 2 including a gas jet disposed near the inlet of the conduit for providing a flow of gas for mixing with the flue gas stream.
2. The burner assembly for a heating furnace according to 2. 24. An RFG inductive burner assembly comprising a fuel nozzle device, a first tile structure and a second tile structure, the fuel nozzle device comprising a flow of fluid fuel along a flow path. A first tile structure having a central opening, the first tile structure having a central opening, the nozzle being arranged for introducing into a combustion zone within a fire chamber of a heating furnace; Are arranged to surround the fuel nozzle and to introduce combustion air passing through the fuel nozzle surrounding the flow passage, the first tile structure surrounding the central opening An outer peripheral surface extending around the tile structure; the second tile structure having a central passageway such that the central passageway surrounds the flow passage. And the second tile structure is located in the central passage. Having an inner surface extending around a circumference of the first tile structure, the inner surface facing the outer peripheral surface of the first tile structure and spaced apart, the outer peripheral surface and the inner surface defining an annular space therebetween. And the first and second tile structures are such that when the burner is operably mounted to the furnace, the annular space is in direct communication with an interior region of the firebox near the combustion zone. The arrangement of the first and second tile structures is such that the flow of RFG from the interior region through the annular space is flowing through the central opening of the first tile structure. RFG induction burner assembly. 25. In a low NO _x furnace containing an RFG induction burner assembly and a firebox providing a combustion zone, the RFG induction burner assembly providing combustion air and fluid fuel to the firebox. An RFG induction burner assembly operably attached to the low NO _x furnace for providing a fuel nozzle device, a first tile structure and a second tile structure. The fuel nozzle arrangement includes a nozzle arranged to introduce a flow of fluid fuel along a flow path into a combustion zone within a fire chamber of a furnace; the first tile structure having a central opening. A portion of the first tile structure is arranged to introduce combustion air through the fuel nozzle, the central opening surrounding the fuel nozzle and surrounding the flow passage, The first tile structure is Having an outer peripheral surface surrounding the central opening and extending around the first tile structure; the second tile structure having a central passage, the second tile structure having the central A passage is disposed to surround the outer peripheral surface of the first tile structure, the second tile structure having an inner surface extending around the central passage, the inner surface being the first tile structure. Facing the outer peripheral surface of and spaced apart, the outer peripheral surface and the inner surface being arranged to define an annular space therebetween, and the first and second tile structures include the annular space. Are arranged in direct communication with the interior region of the firebox near the combustion zone, the first and second tile structures being arranged such that the flow of RFG from the interior through the annular space is the first To be guided by combustion air flowing through the central opening of the tile structure That; RFG induction burner assembly place. 26. Efficient and effective reduction method of the NO _X content in the furnace flue gas: stage and providing a flow of fluid fuel into the combustion zone in the firebox of the heating furnace; flow of combustion air To the combustion zone; burning the fluid fuel and the combustion air in the combustion zone, thereby creating a flame; utilizing the motive force of the flow of the combustion air to Directing a flow of RFG directly from a region within the firebox near the combustion zone, and further interacting the flow of RFG with the fluid fuel and the combustion air within the combustion zone. And a NO _x reduction method by which the generation and release of NO _x in the heating furnace is reduced. 27. where flowing for combustion air along the longitudinal axis of the elongated burner assemblies, NO _X reduction method according to claim 26. 28. A method of operating a burner for a gas-fired heating furnace having a firebox comprises: providing a flow of combustion air; providing a flow of fuel; Mixing; combusting a mixture of the combustion air and the fuel in a combustion zone of the firebox; utilizing the motive force of the combustion air to directly flow the flue gas. Directing a flame of the mixture from an area in the firebox near a combustion zone; 29. The method of operating a burner of claim 28, wherein the combustion air flows along a longitudinal axis of the elongated burner assembly. 30. The burner operating method of claim 28, wherein the step of directing a flow of flue gas from the region utilizes a motive force in the flow of gaseous fuel for combustion. 31. An efficient and effective method for reducing the NO _X content in a combustion furnace combustion exhaust gas generated by combusting combustion air and fluid fuel in a combustion zone of a heating furnace, comprises burning the RFG. A NO _x reduction method comprising using the burner assembly of claim 1 for introduction into an area. 32. An efficient and effective method for reducing the NO _X content in a heating furnace combustion exhaust gas generated by burning combustion air and a fluid fuel in a combustion zone of a heating furnace is a method of burning RFG. A NO _x reduction method comprising using the burner assembly of claim 5 for introduction into an area. 33. The burner assembly of claim 15, comprising at least one burner nozzle for the fluid fuel located near the inlet of the conduit for supplying the fluid fuel through the conduit. . 34. The burner assembly of claim 15 including a fluid fuel burner nozzle disposed on an outer peripheral surface of the annular body segment of the second tile structure. 35. The burner assembly of claim 33, comprising a fluid fuel burner nozzle disposed on an outer peripheral surface of the annular body segment of the second tile structure. 36. The burner assembly of claim 15 including a swirler mounted within the air passage for swirling combustion air and fluid fuel within the air passage. 37. The burner assembly of claim 2 wherein the first and second tile structures are substantially circular and are concentrically mounted. 38. The burner assembly according to claim 2, wherein the first and second tile structures are substantially rectangular. 39. The burner assembly of claim 7, wherein the second tile structure has a plurality of spaced legs that engage mounting structures of the first tile structure. . 40. The burner assembly of claim 39, wherein the mounting structure comprises a plurality of angularly spaced shoulder members, each leg engaging a respective shoulder member. . 41. The burner assembly of claim 7, comprising at least one burner nozzle for the fluid fuel located near the inlet of the conduit for supplying fluid fuel through the conduit. . 42. The burner assembly of claim 41, wherein the second tile structure has a plurality of spaced legs that engage mounting structures of the first tile structure. . 43. The burner assembly of claim 42, wherein the mounting structure comprises a plurality of angularly spaced shoulder members, each leg engaging a respective shoulder member. . 44. The burner assembly according to claim 43, wherein the fluid fuel burner nozzle is angularly offset relative to each of the shoulder members. 45. The burner assembly of claim 43, wherein the burner assembly includes a plurality of burner nozzles, each burner nozzle being angularly offset with respect to each shoulder member. .