AU2016202300A1 - Pilot Protection and Cross Lighting System - Google Patents

Abstract

A pilot light protection system including a housing to substantially enclose a pilot burner, said housing including a substantial portion thereof being constructed of a wall portion which includes apertures therethrough, wherein said housing includes a lower wall portion which has no apertures therethrough. Figure to be published: 1 CY)) CD) ,1/9

Description

Pilot protection and cross lighting system Field of the invention [001] The present invention relates to pilot light protection systems and those that assist in the cross lighting of a burner.

Background of the invention [002] Natural draught gas water heaters generally consist of a permanent pilot which lights a main burner as required. That can be either by manual operation of the gas control or automatically as the temperature of the water in the tank changes.

[003] The requirements of the permanent pilot are to light the main burner under any environmental conditions like temperature and humidity and low or high gas pressures.

[004] US patent 3122195 provides a walled enclosure made from a mesh or aperture plate structure, but provides an inadequate solution to the problem.

[005] Any reference herein to known prior art does not, unless the contrary indication appears, constitute an admission that such prior art is commonly known by those skilled in the art to which the invention relates, at the priority date of this application.

Summary of the invention [006] The present invention provides a pilot light protection system including a housing to substantially enclose a pilot burner, the housing including a substantial portion thereof being constructed of a wall portion which includes apertures therethrough; said housing having a lower wall portion which has no apertures therethrough.

[007] The present invention provides a pilot light protection system including a housing to substantially enclose a pilot burner, the housing including a substantial portion thereof being constructed of a wall portion which includes apertures therethrough, said housing being closed an upper region thereof by a roof structure.

[008] The housing can include an opening in a wall portion closest to a burner, the opening permitting a pilot flame to travel towards the burner.

[009] An upper roof structure can be provided to cooperate with the housing.

[010] The roof structure can include a chimney aperture in an upper surface thereof.

[011] The chimney aperture can include a raised rim around the chimney aperture.

[012] The roof structure can be supported by a wall formation so as to be in a close to, or small, spaced relationship to the top of the housing.

[013] The wall formation can be spaced from a closest wall of the housing, so that an air gap exists between the wall formation and the housing.

[014] The roof structure can have an under surface thereof which is at an angle to a plane which contains the base of the housing.

[015] The roof structure can terminate between the housing and the burner.

[016] The pilot protection system can be utilised with a lighter than air gas burner system, such as natural gas.

[017] The system can include a channel member below the roof structure which will deliver heavier than air gas from the burner toward a pilot flame of the pilot light.

[018] The channel member can be one of: an open channel, a base surface and two side walls; a base surface and a single side wall; a closed channel; a duct.

[019] The channel member can be supported from one of: the roof structure, a support member independent of the roof structure.

[020] The heavier than air gas can be LPG.

[021] The housing can be supported by the same bolt or screw used to support the pilot light.

[022] The roof structure and the housing can be supported by the same bolt or screw used to support the pilot light.

[023] The present invention also provides a cross lighting system for a pilot light and gas burner system wherein said system includes a channel member, bridging at least a part of the distance between said pilot light and said gas burner, said channel member adapted to deliver heavier than air gas from said burner toward said pilot flame.

[024] The channel member can be one of: an open channel, a base surface and two side walls; a base surface and a single side wall; a closed channel; a duct.

[025] The channel member can be supported from one of: a support of said pilot light; a support of said burner; a support member independent of a support of said pilot light and or said burner.

[026] The heavier than air gas can be LPG.

[027] The present invention further provides a pilot light protection system including a roof structure said pilot light said roof structure including a chimney aperture in an upper surface thereof.

[028] The chimney aperture can include a raised rim around said chimney aperture.

[029] The roof structure can be supported by a wall formation so as to be close to or adjacent to the flame location of said pilot light.

[030] The roof structure can have an under surface thereof which is at an angle to a plane which contains the base of said pilot light or the direction of emission of a flame from said pilot light or at an angle to the plane in which the burner is located.

[031 ] The roof structure can terminate close to or over said burner.

[032] The roof structure can be utilised with a lighter than air gas burner system, such as natural gas.

[033] The pilot light can include a pilot burner, an ignition means and a flame detector.

[034] The present invention also provides a burner system including a burner and a pilot protection system as described above.

[035] The present invention further provides a water heater having a burner system including a burner and pilot light having a pilot protection system as described above.

Brief description of the drawings [036] A detailed description of a preferred embodiment will follow, by way of example only, with reference to the accompanying figures of the drawings, in which: [037] Fig. 1 illustrates a perspective view of a pilot protection system installed on a burner of a water heater; [038] Fig.2 illustrates a rear view of a housing of the pilot protection system of Fig. 1; [039] Fig.3 illustrates a front perspective view of the housing of Fig.2; [040] Fig.4 illustrates a plan view of the housing of Fig.3; [041] Fig.5 illustrates a left side view of the housing of Fig.3; [042] Fig.6 illustrates a front view of the housing of Fig.3; [043] Fig.7 illustrates a rear perspective view of a roof member of the protection system of Fig. 1; [044] Fig.8 illustrates a plan view of the roof member of Fig.7; [045] Fig.9 illustrates a side elevation of the roof member of Fig.7; [046] Fig.10 illustrates a front elevation of the roof member of Fig.7; [047] Fig.11 illustrates a rear perspective view of an assembly of the housing of

Fig.2 and the roof member of Fig.7 of the protection system of Fig.1; [048] Fig.12 illustrates a plan view of the assembly of Fig.11; [049] Fig.13 illustrates a side elevation of the assembly of Fig.11; [050] Fig.14 illustrates a front elevation of the assembly of Fig.11; [051] Fig.15 illustrates a rear perspective view of an channel member for use with the protection system of Fig.1; [052] Fig.16 illustrates a plan view of the channel member of Fig.15; [053] Fig.17 illustrates a front elevation of the channel member of Fig.15; [054] Fig.18 illustrates a side elevation of the channel member of Fig.15; [055] Fig.19 illustrates a rear perspective view of a water heater burner with pilot light system and the channel member of Fig.15 installed; [056] Fig.20 illustrates a plan view of the system of Fig.19; [057] Fig.21 illustrates a side view of the system of Fig.19; [058] Fig.22 illustrates a cross section through the housing and roof member of the system of Fig.1 but pilot light is not sectioned; [059] Fig.23 illustrates a cross section through the housing, roof member and pilot light of the system of Fig.1; [060] Fig.24 illustrates plan view of the system of Fig.1; [061] Fig.25 illustrates a side view of the assembly of Fig. 1; [062] Fig.26 illustrates a gas water heater having the protection system described herein; [063] Fig.27 illustrates a detailed view of a lower portion of the gas water heater shown in Fig.26; and [064] Fig.28 is a perspective view sectional view of the gas water heater shown in Fig.27.

Detailed description of the embodiment or embodiments [065] Illustrated in Figs 1 to 25 a pilot light protection system 10 having a housing 20 to substantially enclose a pilot burner 6, the housing 20 including a substantial portion thereof being constructed of an upper wall portion 22 which includes apertures 22.1 there through, with housing 20 having a lower wall portion 21 which has no apertures there through. Depending upon the height of the pilot tube 6 above its mounting plate, the height of the walls of the housing 20 are such that the upper portion, 22 which has apertures 22.1, is approximately two thirds of the wall height, while the lower wall portion 21 is the lower third of the wall height. The upper region 22 preferably has apertures 22.1 of a size of approximately 2mm in diameter, with a centre spacing of approximately 2.85mm, and an angular spacing of about 60 degrees, between adjacent apertures.

[066] The pilot light protection system 10 can also be considered to include only the housing 20 to substantially enclose a pilot burner 6, whereby the housing 20 includes a substantial portion thereof being constructed of an upper wall portion 22 which includes apertures 22.1 through it, with the housing being closed at an upper region thereof by a roof structure 30.

[067] The housing 20 include an opening 23 in a forward wall portion, which is closest to a burner 9, whereby the opening 23 permits a pilot flame (not illustrated) to travel from the pilot tube 6 towards the burner 9, when in use. The opening 23 is in the upper portion 22 and is three sided- that is open at the top and is approximately two thirds the height of the wall The housing 20 is formed from a stainless steel plate or sheet metal in which a multitude of apertures 22.1 are punched through the plate thereof before bending the plate into the required shape, which is best illustrated in Figs 2 to 6. It will be noted the shape of the housing 20 has a vertically extending opening 21.1 through it, and two bevel wall sections 22.1 at the front thereof, on either side of the front upper openings 23.

[068] The housing 20 is preferably formed from a single piece of plate or sheet metal and folded to the required housing shape, which includes a supporting flange 26 which extends perpendicularly and or horizontally away from the periphery of a side wall 20.1 of the housing 20, while a mounting flange 25, which includes a mounting aperture 27 therein, which extends downwardly from the supporting flange 26. It will be particularly noted from Fig.6 that the supporting flange 26 will space or offset the side wall 20.1 of the housing 20, so as to form a gap 24 above the supporting flange 26, the purpose of which will be explained in more detail below in regard to the assembly.

[069] The upper edge of the housing 20 has a spacer section 24.1 which ensures when the housing is assembled to its roof structure 30, that the gap 24 will remain present between the supporting wall 33 of the roof structure 30 as seen in Fig.7 and Fig. 14. The spacer section 24.1 projects away from the wall 20.1 by a distance of approximately 5 mm, and because of the way it is formed, namely by the bending away of a side section 24.2, provides an entrance guarding or protection formation, which can assist to trap dust and particles which may be floating or flowing past the vertical section 24.2.

[070] The upper roof structure 30, as best illustrated in Figs 7 to 10 is provided so as to cooperate with the housing 20. The roof structure 30 has an upper surface 31 which includes a chimney aperture 32 through it, whereby the chimney aperture 32 is located at one end, being a forward end of the system 10, and is so located, that when assembled with the housing 20, is located above and forward of the opening 23 in the housing 20. The chimney aperture 32 has a raised rim 32.1 around the chimney aperture 32. The roof structure 30 is preferably made of pressed stainless steel, with the rim 32.1 being pressed into formation around the chimney aperture 32.

[071] The roof structure 30 has its upper surface 31 bounded on one side by a downwardly extending flange 35, of the order of 4 to 5 mm in height, while on the other side it is supported by a wall formation 33 which has an offset vertical portion 34 provided by a step section 37, with the vertical offset portion 34 finishes with a horizontal flange 36. The roof structure 30 is positioned by means of its support portions and sections, so as to be close to or in contact with the upper edge or rim of the upper wall portion 22 of the housing 20. In being assembled in this way the roof structure 30 has the flange 35 terminating below the upper rim 20.11 or edge of the upper portion 22 on one side, while on the other side 20.1, the wall 20.1 will be spaced by the gap 24 from the portion 33 of the roof structure 30.

[072] The height of the vertical offset portion 34 is of a height so as to receive the height of the support 25 on the housing 20, as well as the mounting bracket 6.1 of the pilot tube 6 mounting, so that all three components, when assembled by a bolt or screw through respective holes 27, 34.1 and 6.2, will be in correct location and alignment with respect to each other. The support 25 on the housing 20 and the vertical offset portion 34 of the roof structure 30 are spot welded together to secure the assembly.

[073] The wall 20.1 of the housing 20 is spaced by the gap 24 from the support portion 33, so that an air passage or gap exists between them allowing air to enter the housing through all sides thereof. This ensures that there is plenty of oxygen available or the burning of the gas ejected from the pilot tube 6.

[074] It will be noted from Figs 22, 23 and 25 that the lower surface of the portion 31 of the roof structure 30 is at an angle of the order of 4 to 5 degrees to a plane which contains the base of the housing 20 and also the upper rim 20.11 of the upper portion 22. In use, the base would generally be located in a horizontal plane. The lower or under surface of the portion 31 of the roof structure 30 is, between the opening 23 to the chimney aperture 32, generally planar to assist with passage of lighter than air gases.

[075] The roof structure 30 has its upper portion 31 and its outer most edge 31.1 terminating over the burner 9 to thereby provide a conduit mechanism between the housing 20 and the rim of the burner 9, as is best illustrated in Figs 24 and 25.

[076] The pilot protection system 10, can be utilised with a lighter than air gas burner 9, such as one which burns natural gas. In this scenario, any gas emitted from the burner 9, whether under high pressure or very low pressure, will deliver lighter than air gas to the chimney aperture 32 of the roof structure 30. At this location, the pilot flame which is travelling out through the opening 23 and directed to the chimney aperture 32, whereby the natural gas, the buoyancy of which has moved it to the region of the chimney aperture 32, will be ignited or cross-lighted by the pilot flame.

[077] The housing 20 with its roof structure 30 ensures that downward drafts will have no effect on the pilot flame, when the parts are assembled. Additionally the side wall 33 of the structure 30 ensures that cross draughts will have a much more diminished effect in one direction and little to no effect in the other direction, while front draughts will be deflected by the bevelled portions 21.2, with only a relatively small opening 23 being available for a front directed draft to act upon the pilot flame, but as the front of the housing is somewhat protected by being in the shadow of the burner 9 in that direction, a front draft will cause very little problem to the system. A rear draft will only be able to access the pilot flame through the apertures 22.1, and thus will have very little deleterious effect on the pilot flame.

[078] The system 10, for heavier than air gas burners, includes a channel member 40, which is best illustrated in Figs 15 to 18, and is visible in Fig. 1 and 19 to 21. It is designed to be positioned below the roof structure 30, so as to deliver heavier than air gas from the burner 9 toward a pilot flame of the pilot light.

[079] The channel member 40 is of an open channel design in the figures, but can provided as a base surface and two side walls, or a base surface and a single side wall as illustrated in Fig 15. As an alternative it could also be provided as a closed channel or a duct.

[080] The channel member 40 as illustrated in Figures 15 to 18 has a vertical flange 45 which extends upwardly from a horizontal surface portion 44. Extending downwardly on the other side is a vertical support portion 41 which terminates in a turned up portion 42 so as to clip the channel member 40 to lower edge of the upper burner support 7, as best illustrated in Figs 1, and 19 to 21. The vertical support portion has a punch and folded side projecting formation or tab 43 which will engage the upper horizontal surface of the support 7, to clamp the member 40 in place onto the side edge of the support 7.

[081] While the channel member 40 illustrated as being supported from the burner support 7, it will be understood that a shaped duct or channel formation could be formed as part of the roof structure 30, or it could be attached to the burner or from another component of the water heater.

[082] The pilot light system will usually include a pilot burner being via pilot tube 6, an ignition means such as a spark igniter 6.3 and a flame detector such as a thermocouple 6.5 all visible in Figs 22 and 23. It will be noted that the housing 20 surrounds the pilot burner 6 and the igniter 6.3 but the thermocouple or flame sensor 6.5 is located outside the front of the housing 20 between the pilot burner 6 and the chimney aperture 32.

[083] Illustrated in Figs 26 to 28 is a gas fired water heater 50 which has the pilot system and protection system 10 as described above therein. Figs 27 and 28 show a detailed view of the lower portion of the water heater of Fig 26. The depicted water heater 50 includes an outer wall or jacket 52 in which is contained a generally cylindrical water tank 54.1 with a domed or plus end 54.11. The outer jacket 52 also surrounds a lower housing 53 which houses the burner components. The water tank 54.1 is situated above, and is supported by, the lower housing 53 so that water is heated by the combustion products of the burner.

[084] The water tank 54.1 includes a central flue 56 in which air heated by the burner 9 will rise. A casing 54.2 also has a cylindrical sidewall and a domed top 54.21 which overlies the water tank 54.1. The casing 54.2 and the water tank 54.1 are spaced from each other to provide an annular space 54.3 into which air rising up and out from the flue 56 can be directed downwardly around the outside of the tank 54.1. A spacer formation 54.31 assists in maintaining the annular space 54.3. An outer gap 58.1 is also provided between the outboard side of the casing 54.2 and an inboard side of an outer casing 58 to provide passage for upwardly moving combustion gasses to move to an exit passage 52.1 for the exhaust of combustion products from thewater heater 50.

[085] As best seen in Fig 28, the walls of the water tank 54.1 are further closed by a flange 59, which is a projecting flange of the minus end 55. The flange 59 and the minus end 55 are provided to close the annular wall of the water tank 54.1, and to seal the bottom of the passages external of the tank 54.1 to separate the combustion chamber defined by the lower housing 53 from the circulation path of the exhaust gases or combustion products, and to define a convoluted combustion products exhaust passage.

[086] The flange 59 is shaped and dimensioned to have an inner perimeter 59.1 that is sized to accommodate or receive the water tank 54.1, the inner perimeter 59.1 and the water tank 54.1 being attached. A spacer portion 59.2 which is at an angle to the inner perimeter 59.1 is provided adjacent the inner perimeter 59.1. When the water heater 50 is assembled, the spacer portion 59.2 will be generally located beneath and spaced from the lower rim of the casing 54.2. The spacer portion 59.2 is located between the inner perimeter 59.1 and a corner or a channel 59.3, and the corner or channel 59.3 extends into an outer collar 59.4 which projects upwardly.

[087] The corner, groove, or channel 59.3 provided in the flange 59 is adapted to accommodate or receive the outer casing 58, which will be located external to and spaced from the casing 54.2. The outer casing 58 is provided around a lower portion of the water tank 54.1. Therefore, the combustion products rising from the flue 56 will travel into the gap 54.3 between the water tank 54.1 and the casing 54.2. From the aforementioned gap 54.3, the combustion products will then descend and will pass through the space between the casing 54.2 and the spacer portion 59.2 and then ascend again into the gap 58.1 between the casing 54.2 and the outer casing 58.

[088] The aperture 52.1 located at a middle or middle-to-lower height of the water heater 50 is provided through the outer jacket 52, at a height which is lower than the upper extent of the outer casing 58.. The aperture 52.1 is provided for the ascending exhaust gases travelling between the casing 54.2 and the outer casing 58 to exit the water heater 50.

[089] The gas burner 9, the pilot light 6, and the pilot light protection system 10 are located in the space defined by the lower housing 53. The gas burner 9 is thus located beneath the curved dome 55, in a position vertically under the flue 56. A heat deflector or shield 57 is provided below and around the periphery of the gas burner 9 to further minimise heat loss. The pilot light 6 and the pilot protection system 10 are provided to interact with the gas burner 9 in the manner described above with reference to e.g. Figs 1 and 19 to 25.

[090] The pilot light 6 is connected to a gas controller 60 which is externally attached to a lower portion of the outer wall 52, and which provides the gas control system and a piezo electric starter to start and maintain the pilot light 6. The connecting conduits and cables 64 between the pilot light 6 and the gas controller 60 exit the water heater 50 via a cut-out, exits or port 66 located in the lower housing 53 and or the water heater outer wall 52, best seen in Fig 28. Fresh air is also drawn into the burner compartment defined by the lower housing 53 through the openings. In the depicted embodiment, corresponding cut-outs or openings 66 are provided in the lower housing wall 53 and the outer wall 52, with a bridging wall 67 between the outer wall 52 and the lower housing 53 adjacent the opening 66. The bridging wall 67 and the corresponding openings 66 define a port from the cables 64. Also the bridging wall helps prevent cold air, dust, etc., from entering the areas of the water heater 50 adjacent to the water tank 54.1, and in particular from entering the circulation of the heated air.

[091] At or around the height of the gas controller 60, the water heater 50 include a temperature sensor 62 (see Fig 26 and Fig 27) to shut down gas supply to the burner when the water reaches the set temperature. The gas controller 60 is connected to the temperature sensor 62 which is located within the tank 54.1, at a height near or above the lowest part of the flue 56.

[092] Fig 28 shows the lower portion of a slightly different gas water heater which includes the pilot protection system 10.

[093] While the above description has the upper region of the housing 20 wall being preferred to be a plate or sheer metal with apertures through it, it will be understood that the upper region can be constructed from wire mesh, such as brass or stainless steel, with a wire size of, for example, 20. That is, there are 20 wires per square inch. The wire diameter is 0.9mm, forming apertures of 2mm to 2.5mm in size between wires. These parameters result in a 50% to 55% open mesh.

[094] While the protection system 10 is illustrated in Figs 26 to 28 as being installed in a water heater of the above described construction, it will be understood that the protection system can be applied to gas water heaters of other constructions which may or may not have a tank, such as instantaneous gas water heaters.

[095] The above description and the drawings illustrate the housing 20, the roof structure 30 and channel member 40 being utilised together. However it will be understood that the housing 20 could be used on its own with a suitable aperture plate roof or mesh roof, while the roof structure 30 could also be used on its own. The housing 20 will provide better protection for flame than the prior art, while the structure and features of the roof structure 30 will also provide some protection and an effective chimney to existing pilot systems if used on its own. Figs 19 to 20 show the channel member 40 in use on its own.

[096] Where ever it is used, the word “comprising” is to be understood in its “open” sense, that is, in the sense of “including”, and thus not limited to its “closed” sense, that is the sense of “consisting only of. A corresponding meaning is to be attributed to the corresponding words “comprise”, “comprised” and “comprises” where they appear.

[097] It will be understood that the invention disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text. All of these different combinations constitute various alternative aspects of the invention.

[098] While particular embodiments of this invention have been described, it will be evident to those skilled in the art that the present invention may be embodied in other specific forms without departing from the essential characteristics thereof. The present embodiments and examples are therefore to be considered in all respects as illustrative and not restrictive, and all modifications which would be obvious to those skilled in the art are therefore intended to be embraced therein.

Claims (30)

1. Claims

   1. A pilot light protection system including a housing to substantially enclose a pilot burner, said housing including a substantial portion thereof being constructed of a wall portion which includes apertures therethrough, wherein said housing includes a lower wall portion which has no apertures therethrough.
2. 2. A pilot light protection system including a housing to substantially enclose a pilot burner, the housing including a substantial portion thereof being constructed of a wall portion which includes apertures therethrough, said housing being closed an upper region thereof by a roof structure.
3. 3. A system as claimed in any one of the preceding claims, wherein said housing includes an opening in a wall portion closest to a burner, said opening permitting a pilot flame to travel towards said burner.
4. 4. A system as claimed in any one of the preceding claims, wherein an upper roof structure cooperates with said housing.
5. 5. A system as claimed in claim 4, wherein said roof structure includes a chimney aperture in an upper surface thereof.
6. 6. A system as claimed in claim 5, wherein said chimney aperture includes a raised rim around said chimney aperture.
7. 7. A system as claimed in any one of claims 4 to 6, wherein said roof structure is supported by a wall formation so as to be in a close to, or small, spaced relationship to the top of said housing.
8. 8. A system as claimed in claim 7, wherein said wall formation is spaced from a closest wall of said housing, so that an air gap exists between said wall formation and said housing.
9. 9. A system as claimed in any one of claims 2, or 4 to 8, wherein said roof structure has an undersurface thereof which is at an angle to a plane which contains the base of said housing.
10. 10. A system as claimed in any one of claims 2, or 4 to 9, wherein said roof structure terminates close to or over said burner.
11. 11. A system as claimed in any one of claims 1 to 10, wherein said system is utilised with a lighter than air gas burner system, such as natural gas.
12. 12. A system as claimed in any one of claims 1 to 10, wherein said system includes a channel member below said roof structure which will deliver heavier than air gas from said burner toward said pilot flame.
13. 13. A system as claimed in claim 12, wherein said channel member is one of: an open channel, a base surface and two side walls; a base surface and a single side wall; a closed channel; a duct.
14. 14. A system as claimed in claim 12 or 13, wherein said channel member is supported from one of: said roof structure, a support member independent of said roof structure.
15. 15. A system as claimed in any one of claims 12 to 14, wherein said heavier than air gas is LPG.
16. 16. A system as claimed in anyone of claims 1 to 15, wherein said housing is supported by the same bolt or screw used to support said pilot light.
17. 17. A system as claimed in any one of claims 2, 4 to 16, when appended directly or indirectly to claim 2 or 4, wherein said roof structure and said housing are supported by the same bolt or screw used to support said pilot light.
18. 18. A cross lighting system for a pilot light and gas burner system wherein said system includes a channel member, bridging at least a part of the distance between said pilot light and said gas burner, said channel member adapted to deliver heavier than air gas from said burner toward said pilot flame.
19. 19. A system as claimed in claim 18, wherein said channel member is one of: an open channel, a base surface and two side walls; a base surface and a single side wall; a closed channel; a duct.
20. 20. A system as claimed in claim 18 or 19, wherein said channel member is supported from one of: a support of said pilot light; a support of said burner; a support member independent of a support of said pilot light and or said burner.
21. 21. A system as claimed in any one of claims 18 to 10, wherein said heavier than air gas is LPG.
22. 22. A pilot light protection system including a roof structure said pilot light said roof structure including a chimney aperture in an upper surface thereof.
23. 23. A system as claimed in claim 22, wherein said chimney aperture includes a raised rim around said chimney aperture.
24. 24. A system as claimed in any one of claims 22 or 23, wherein said roof structure is supported by a wall formation so as to be close to or adjacent to the flame location of said pilot light.
25. 25. A system as claimed in any one of claims 22 to 24, wherein said roof structure has an undersurface thereof which is at an angle to a plane which contains the base of said pilot light or the direction of emission of a flame from said pilot light.
26. 26. A system as claimed in any one of claims 22 to 25, wherein said roof structure terminates over said burner.
27. 27. A system as claimed in any one of claims 22 to 26, wherein said system is utilised with a lighter than air gas burner system, such as natural gas.
28. 28. A system as claimed in any one of the preceding claims wherein said pilot light includes a pilot burner, an ignition means and a flame detector.
29. 29. A burner system including a burner and a pilot protection system as claims in any one of claims 1 to 18.
30. 30. A water heater having a burner system including a burner and pilot light having a pilot protection system as claimed in any one of claims 1 to 18.