PILOT BURNER ASSEMBLY

Abstract

A pilot burner assembly includes a grounded conduit defining one or more first fluid inlets for receiving a first fluid, and a main outlet. The assembly further includes a conductive conduit extending within the grounded conduit such that an annular chamber is formed therebetween, the conductive conduit defining a second fluid inlet for receiving a second fluid, and one or more second fluid outlets for discharging the second fluid into the annular chamber such that the first and second fluids mix in the annular chamber to form a combustible mixture. Moreover, the assembly includes an igniter tip electrically connected to the conductive conduit and arranged adjacent to the one or more second fluid outlets, wherein the igniter tip is spaced from the grounded conduit such that an electrical current applied to the igniter tip generates a spark between the igniter tip and the grounded conduit for igniting the combustible mixture.

Claims

1. A pilot burner assembly comprising: a grounded conduit electrically connected to a ground, the grounded conduit defining one or more first fluid inlets for receiving a first fluid, and a main outlet; a conductive conduit comprising an electrically conductive material and extending at least partially within the grounded conduit such that an annular chamber is formed therebetween, the conductive conduit defining a second fluid inlet for receiving a second fluid, and one or more second fluid outlets for discharging the second fluid into the annular chamber such that the second fluid mixes with the first fluid in the annular chamber to form a combustible mixture; and an igniter tip electrically connected to the conductive conduit and arranged adjacent to the one or more second fluid outlets of the conductive conduit, wherein the igniter tip is spaced from the grounded conduit such that an electrical current applied to the igniter tip via the conductive conduit generates a spark between the igniter tip and the grounded conduit for igniting the combustible mixture to produce a pilot flame at the main outlet of the grounded conduit.

2. The pilot burner assembly according to claim 1, further comprising a housing defining a chamber that at least partially receives the conductive conduit.

3. The pilot burner assembly according to claim 2, wherein the housing defines a housing inlet, and the chamber of the housing is fluidly coupled to the one or more first fluid inlets of the grounded conduit such that the first fluid can be conveyed through the housing inlet into the chamber of the housing, and then through the chamber into the one or more first fluid inlets of the grounded conduit.

4. The pilot burner assembly according to claim 3, wherein the housing defines a housing outlet, and the one or more first fluid inlets of the grounded conduit comprises a first fluid inlet arranged at the housing inlet such that the first fluid can be conveyed through the housing inlet into the chamber of the housing, and then through the chamber into the first fluid inlet via the housing outlet.

5. The pilot burner assembly according to claim 3, further comprising a fan that is operable to convey the first fluid through the housing inlet into the chamber of the housing, and then through the chamber into the one or more first fluid inlets of the grounded conduit.

6. The pilot burner assembly according to claim 3, wherein the grounded conduit is received at least partially within the chamber of the housing such that the one or more first fluid inlets of the grounded conduit are arranged within the chamber.

7. The pilot burner assembly according to claim 2, wherein the housing defines a housing opening for receiving the second fluid therethrough, and the pilot burner assembly comprises a fluid coupling configured to convey the second fluid received through the housing opening to the second fluid inlet of the conductive conduit, wherein the fluid coupling comprises an electrically insulating material.

8. The pilot burner assembly according to claim 2, wherein: the conductive conduit defines one or more venturi outlets for discharging a portion of the second fluid upstream of the one or more second fluid outlets, and the pilot burner assembly comprises a deflector body configured to deflect the portion of the second fluid exiting the one or more venturi outlets toward the one or more second fluid outlets.

9. The pilot burner assembly according to claim 8, wherein the deflector body comprises an annular body that surrounds the conductive conduit to define an annular venturi chamber therebetween.

10. The pilot burner assembly according to claim 2, wherein the housing defines a cable opening, and the pilot burner assembly further comprises an ignition cable that extends through the cable opening and is electrically connected to the conductive conduit.

11. The pilot burner assembly according to claim 1, further comprising a flame rectification rod electrically coupled to the igniter tip and arranged adjacent to the main outlet of the grounded conduit.

12. A method of operating the pilot burner assembly according to claim 1, wherein: the first fluid flows into the grounded conduit via the one or more first fluid inlets and through the annular chamber between the grounded conduit and conductive conduit, the second fluid flows into the conductive conduit via the second fluid inlet and is discharged into the annular chamber via the one or more second fluid outlets, thereby mixing with the first fluid in the annular chamber to form the combustible mixture, and the electrical current is applied to the igniter tip via the conductive conduit, such that the spark is generated between the igniter tip and the grounded conduit, which ignites the combustible mixture to produce the pilot flame at the main outlet of the grounded conduit.

13. The method according to claim 12, wherein: the pilot burner assembly comprises a housing defining a housing inlet and a chamber that at least partially receives the conductive conduit, and the first fluid flows through the housing inlet into the chamber of the housing, and then through the chamber into the one or more first fluid inlets of the grounded conduit.

14. The method according to claim 13, wherein: the housing defines a housing outlet, the one or more first fluid inlets of the grounded conduit comprises a first fluid inlet arranged at the housing inlet, and the first fluid flows through the housing inlet into the chamber of the housing, and then through the chamber into the first fluid inlet via the housing outlet.

15. The method according to claim 13, wherein the pilot burner assembly comprises a fan that is operated to convey the first fluid through the housing inlet into the chamber of the housing, and then through the chamber into the one or more first fluid inlets of the grounded conduit.

16. The method according to claim 13, wherein the grounded conduit is received at least partially within the chamber of the housing such that the one or more first fluid inlets of the grounded conduit are arranged within the chamber.

17. The method according to claim 13, wherein: the housing defines a housing opening that receives the second fluid therethrough, and the pilot burner assembly comprises a fluid coupling that conveys the second fluid received through the housing opening to the second fluid inlet of the conductive conduit, wherein the fluid coupling comprises an electrically insulating material.

18. The method according to claim 2, wherein: the conductive conduit defines one or more venturi outlets that discharge a portion of the second fluid upstream of the one or more second fluid outlets, and the pilot burner assembly comprises a deflector body that deflects the portion of the second fluid exiting the one or more venturi outlets toward the one or more second fluid outlets.

19. The method according to claim 18, wherein the deflector body comprises an annular body that surrounds the conductive conduit to define an annular venturi chamber therebetween.

20. The method according to claim 12, wherein the first fluid comprises combustion air and the second fluid comprises a gaseous fuel.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The above and other features, examples and advantages of aspects or examples of the present disclosure are better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0007] FIG. 1 is a perspective view of a first embodiment of a pilot burner assembly;

[0008] FIG. 2 is a schematic cross-section view of the first embodiment of the pilot burner assembly;

[0009] FIG. 3 is a schematic cross-section view of a second embodiment of the pilot burner assembly;

[0010] FIG. 4 is a schematic cross-section view of a third embodiment of the pilot burner assembly; and

[0011] FIG. 5 is a schematic cross-section view of a fourth embodiment of the pilot burner assembly.

DETAILED DESCRIPTION

[0012] With reference to FIGS. 1 and 2, a first example embodiment of a pilot burner assembly 10 is shown, which comprises a housing 14 having a main body 16, an upper lid 18, and a base 20 that collectively define a chamber 26 therein. The lid 18 of the housing 14 defines a housing inlet 30 for delivering a first fluid 32 into the chamber 26, which in the present example corresponds to combustible air. Moreover, the pilot burner assembly 10 comprises a grounded conduit 34 electrically connected to ground 38, wherein the grounded conduit 34 has a main outlet 42 and a first fluid inlet 44 fluidly connected at a housing outlet 46 defined by the main body 16 of the housing 14. As such, the first fluid 32 (e.g., combustible air) can flow through the housing inlet 30 into the chamber 26, and then into the grounded conduit 34 via the housing outlet 46 and first fluid inlet 44 of the grounded conduit 34.

[0013] The pilot burner assembly 10 further includes a conduit assembly 52 comprising an inlet body 56, a conductive conduit 58, and a series of fluid couplings 60a-d fluidly coupling the inlet body 56 to the conductive conduit 58. The inlet body 56 can be fluidly coupled to a fluid source for receiving a pressurized second fluid 66, which in the present example corresponds to a gaseous fuel (e.g., natural gas). Moreover, the conductive conduit 58 defines a fluid inlet 68 at a proximal end thereof, a distal outlet 70 at a distal end thereof, and a plurality of main fluid outlets 72 slightly upstream from the distal outlet 70. As such, the second fluid 66 received by the inlet body 56 can flow into the fluid inlet 68 of the conductive conduit 58 via the fluid couplings 60a-d, and then flow through the conductive conduit 58 until it is discharged through the distal and main fluid outlets 70, 72 of the conductive conduit 58.

[0014] Notably, the conductive conduit 58 in the present example is a single tube- or pipe-like body comprising an electrically conductive material (e.g., copper, silver, etc.), such that the conductive conduit 58 is conductive from its proximal end to its distal end. However, for the purposes of this disclosure, a conduit can comprise any configuration having a single fluid element (e.g., pipe, tube) or a plurality of fluid elements (e.g., pipes, tubes, fluid couplings etc.) that are fluidly coupled together, such that the fluid element(s) can convey a fluid therethrough from one or more fluid inlets to one or more fluid outlets.

[0015] The conduit assembly 52 in the present example is arranged such that the inlet body 56 is located outside of the housing 14 and the fluid coupling 60a extends through a housing opening 80 defined by the main body 16 of the housing 14. The remaining fluid couplings 60b-c are arranged within the chamber 26 of the housing 14, while the conductive conduit 58 extends from within the chamber 26 of the housing 14 into the grounded conduit 34. As arranged, an annular chamber 84 will be defined between the conductive conduit 58 and the grounded conduit 34. Moreover, the first and second fluid couplings 60a, 60b can be threadably coupled together such that the first fluid coupling 60b applies pressure against a sealing plate 86 that seals the housing opening 80. This threaded attachment and pressure against the sealing plate 86 will also serve to fix the conduit assembly 52 in its position relative to the housing 14.

[0016] The pilot burner assembly 10 further includes an ignitor tip 90 that is electrically connected to the conductive conduit 58 and comprises an electrically conductive material (e.g., copper, silver, etc.). In particular, the ignitor tip 90 comprises a conduit portion 90a that is at least partially inserted (e.g., threadably inserted) through the distal outlet 70 of the conductive conduit 58, and an annular flange portion 90b that extends radially from the conduit portion 90a, such that the flange portion 90b is adjacent and downstream to the main fluid outlets 72. Moreover, the ignitor tip 90 is slightly spaced from the grounded conduit 34, such that an annular gap is provided between the flange portion 90b of the ignitor tip 90 and the grounded conduit 34.

[0017] Lastly, the pilot burner assembly 10 includes an ignition cable 92 that extends through a cable opening 94 defined by the lid 18 of the housing 14, and a conductive member 96 that is arranged within the housing chamber 26 and electrically connects the ignition cable 92 to the fluid coupling 60c of the conduit assembly 52. Moreover, a grommet 98 can be arranged within the cable opening 94 to provide a seal between the ignition cable 92 and cable opening 94.

[0018] Notably, the fluid couplings 60c, 60d of the conduit assembly 52 each comprise a conductive material (e.g., copper, silver, etc.). Moreover, as discussed above, the conductive conduit 58 is likewise conductive and electrically connected to the ignitor tip 90. In this manner, the ignition cable 92 will be electrically connected to the ignitor tip 90 via the fluid couplings 60c, 60d and conductive conduit 58. Meanwhile, the fluid coupling 60b preferably comprises an electrically insulating material (e.g., polyvinyl chloride), such that the conductive conduit 58, fluid couplings 60c, 60d, and ignitor tip 90 will be electrically isolated from the fluid coupling 60a and inlet body 56 of the conduit assembly 52.

[0019] As configured, the first fluid 32 (e.g., combustion air) can be conveyed through the housing inlet 30 into the housing chamber 26, and then into the annular chamber 84 defined between the conductive conduit 58 and grounded conduit 34. Meanwhile, the second fluid 66 (e.g., natural gas) can be conveyed through the inlet body 56 and fluid couplings 60a-d into the conductive conduit 58, and then through the conductive conduit 58 until it is discharged at least partially through the main fluid outlets 72 of the conductive conduit 58 into the annular chamber 84. The first fluid 32 and second fluid 66 can then mix within the annular chamber 84 in the vicinity of the ignitor tip 90 to form a combustible mixture. Moreover, an external power source electrically connected to the ignition cable 92 can be operated to apply an electrical current to the ignition cable 92, which in turn will be applied to the ignitor tip 90 via the conductive member 96, fluid couplings 60c, 60d, and conductive conduit 58. This electrical current will generate a spark extending from the flange portion 90b of the igniter tip 90 to the grounded conduit 34 that ignites the combustible mixture and produces a pilot flame at the main outlet 42 of the grounded conduit 34. Moreover, in some examples, a portion of the second fluid 66 conveying through the conduit assembly 52 can be discharged through the distal outlet 70 of the conductive conduit 58 and conduit portion 90a of the igniter tip 90 to supplement the pilot flame.

[0020] It is to be appreciated that various modifications can be made to the pilot burner assembly 10 without departing from the scope of the disclosure. For example, FIGS. 3-5 show three other example embodiments of the pilot burner assembly 10, wherein like reference numerals are used designate identical or similar elements to those described above with respect to the first embodiment.

[0021] In the embodiments shown in FIGS. 3 and 4, the pilot burner assembly 10 comprises a fan 106 that is operable to convey the first fluid 32 through the housing inlet 30 into the chamber 26 of the housing 14, and then through the chamber 26 into the grounded conduit 34. In particular, the grounded conduit 34 in FIG. 3 has a plurality of first fluid inlets 44 that can receive the first fluid 32 conveying through the housing chamber 26. Meanwhile, the pilot burner assembly 10 in FIG. 4 comprises an air conduit 110 that fluidly couples the fan 106 to the housing inlet 30, such that the first fluid 32 is conveyer from the fan 106 through the air conduit 110 and into the housing chamber 26. Moreover, in both the embodiments shown in FIGS. 3 and 4, the pilot burner assembly 10 comprises a flame rectification rod 112 that is electrically coupled to and threadably inserted within the conduit portion 90a of the igniter tip 90, such that the flame rectification rod 112 is arranged adjacent to the main outlet 42 of the grounded conduit 34 where the flame is produced. Notably, the ignition cable 92, cable opening 94, conductive member 96, and grommet 98 are not shown in FIGS. 3 and 4 for clarity.

[0022] In the embodiment shown in FIG. 5, the conductive conduit 58 defines a plurality of venturi outlets 114 for discharging a portion of the second fluid 66 upstream of the conductive conduits distal and main outlets 70, 72. Moreover, the fluid coupling 60d of the conduit assembly 52 defines an annular deflector body 118 that surrounds the conductive conduit 58 in the vicinity of the venturi outlets 114 to define an annular venturi chamber 124 therebetween. As such, the second fluid 66 will enter the annular venturi chamber 124 and be deflected by the deflector body 118 toward the conductive conduits distal and main outlets 70, 72. Moreover, this flow of the second fluid 66 will produce a venturi effect that draws the first fluid 32 with the second fluid 66 toward the conductive conduits distal and main outlets 70, 72.

[0023] Embodiments of the invention have been described for illustrative and not restrictive purposes, and alternative embodiments will become apparent to readers of this patent. Accordingly, the present invention is not limited to the embodiments described above or depicted in the drawings, and various embodiments and modifications may be made without departing from the scope of the claims below.