NZ337658A - Gas igniter for solid fuel burner securable to outside of firebox - Google Patents

Description

NEW ZEALAND PATENTS ACT, 1953 No: 337658 Date: 6 September 1999 COMPLETE SPECIFICATION "Fire Initiation Apparatus" I, HOWARD KEITH SINGER, a New Zealand citizen of 317 Whareora Road, Whangarei, New Zealand, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement: The present invention relates to a fire ignition means. In particular, although not solely, this invention relates to an ignition system for lighting combustible material, such as wood, wood pellets and coal, within conventional fireboxes whether they are stand alone or open fireplaces.

Manually starting a fire in a fire place is a tedious and time consuming and dirty task. Apparatus have been devised in the past to overcome the difficulties inherent in manually starting a fire in a fire place. It is known to mount a starter element or burner in the fire place and to connect the starter element to a supply of gas. The natural gas is released by the starter element adjacent to the wood or other combustible material in the fire place and externally ignited. The combustion of the natural gas facilitates the ignition of the combustible material in the fire place and may be discontinued after the fire is self sustaining.

The use of igniting devices is known in prior art, an example can be seen in US5800158, which details an outdoor open fire igniter. This device is a portable igniter, which utilises a portable gas tank and hand held gas outlet pipe to enable lighting of outdoor fires, such as campfires, without requiring conventional kindling whether the wood is wet or dry. The user of this apparatus must apply a flame to the gas outlet to ignite the gas, and then must direct this flame to the open fire to set the wood alight. Furthermore, portable gas hand torches used in the lighting of fires are known.

Conventional fire place starter apparatus suffer from several insufficiencies. Foremost is the lack of a source of natural gas in many buildings. It is difficult, expensive and in most cases, impossible to install a natural gas pipeline system in an existing building.

To overcome this problem, systems have been devised in the past that are portable and self contained, such as is shown in US Patent No.4522585. Such portable systems use a canister of a pressurised fuel such as butane or propane located exterior to the fire place. The fuel is conveyed into the fire place and is released by a starter element or burner placed on the bottom of the fire place beneath the wood or other combustible material. The fuel is then ignited as in permanently installed systems.

Although such portable systems are desirable for use in fire places that are not otherwise connected to a source of natural gas or the like, they still exhibit certain undesirable characteristics. It is sometimes desirable to remove the apparatus from the fire place during periods of non-use, for cosmetic or safety reasons. This requires that the starter element be removed from the bottom of the fire place, carrying with it ashes, soot and other undesirable contaminants. Frequent cleaning of the starter element is messy and time consuming.

US4779608 describes an invention where the fire place starter apparatus provides a canister of a pressurised fuel conveyed by a pipe to a starter element or burner within a fire place. A valve controls the flow of the fuel from the canister. The starter element is secured in a predetermined fixed position to the grate supporting wood. Here the burner may remain in the fire place, permanently attached to the grate. The pipe and replacement canister are disconnectable and may be stored.

In US5033454 a fire place starting apparatus is described. This apparatus includes a control valve for controlling the flow of flammable gas to a fire place burner, with the control valve being adapted for permanent installation in a structure external of and adjacent to the fire place. The apparatus includes a conduit connectable at one end of the fire place burner within the fire place and at the other end to the control valve. In one embodiment, the device may be provided with a remote operable ignition or re-ignition device including an igniter mountable adjacent the burner within the firebox, an actuator located adjacent to the control valve and means operably connecting the actuator to the igniter. A sensor adjacent to the igniter may detect the absence of a flame and cause the igniter to light the gas flame upon start up and also during operation of the gas flame is extinguished while the gas is still flowing. The device may include provision for both a gas conduit to the burner and electrodes for the lighter and a sensor to pass through one knock out hole in the fire place.

Accordingly it is an object of the present invention to provide an ignition system for lighting combustible material that overcomes the abovementioned disadvantages or which will at least provide the public with a useful choice.

In one aspect the present invention broadly consists in a solid fuel ignition means securable to the outside of a firebox comprising or including: a gas nozzle, having a combustion chamber, an inlet and an outlet, a gas source, a gas valve, a conduit connecting said gas source to said gas valve, said gas valve being connected to the inlet of said nozzle by a second conduit, wherein said nozzle is adapted to be secured to a wall of said firebox such that the flame projected through the outlet of said gas nozzle can pass through an aperture in said wall of said firebox to impinge on said solid fuel within said firebox.

In a further aspect the present invention consists in a firebox which includes an ignition means as hereinbefore described, mounted on the outside of said firebox.

In yet a further aspect the present invention consists in a method of providing enhanced ignition of solid fuel within a firebox, said method comprising the steps of: (1) providing within the wall of the firebox an aperture, (2) fitting the outlet of a gas nozzle to said aperture, (3) connecting to the inlet of said gas nozzle to said gas valve by was of a first conduit, (4) connecting said gas valve to said gas source by was of a second conduit, wherein upon depression and turning of said gas valve by a user, a flame is ignited in said nozzle, said flame impinging on said solid fuel within said firebox.

This invention may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, and any or all combinations of any two or more of said parts, elements or features, and where specific integers are mentioned herein which have known equivalents in the art to which this invention relates, such known equivalents are deemed to be incorporated herein as if individually set forth.

The invention consists in the foregoing and also envisages constructions of which the following gives examples.

One preferred form of the present invention will now be described with reference to the accompanying drawings in which; Figure 1 is a side view of the preferred form of the gas jet nozzle, Figure 2 is an end view of the nozzle and bracket of the present invention of Figure 1 when mounted to the firebox wall, Figure 3 is a cross-sectional side view of the gas nozzle of Figure 1, as fitted to a steel back of a freestanding fireplace, Figure 4 is a cross-sectional side view of the gas nozzle as fitted to a brick fireplace, Figure 5 is a front view of a firebox fitted with the apparatus of the present invention, showing the location of the gas valve in the firebox pedestal, Figure 6 is a side view of a firebox fitted with the apparatus of the present invention showing an alternative location for the gas valve and optional ignition/re-ignition device, namely in the side panel of the pedestal, Figure 7 is a top view of a firebox fitted with the apparatus of the present invention showing an alternative location for the gas valve, namely attached to the back wall of the firebox at the top edge of the fireplace, Figure 8 is a back view of a firebox fitted with the apparatus of the present invention as located to the back wall of the firebox, as in Figure 7, Figure 9 is a back view of a firebox fitted with the apparatus of the present invention as located in the side panel of the pedestal, as in Figure 6, Figure 10 is a perspective cutaway view of a firebox fitted with the apparatus of the present invention, showing the location of the gas nozzle, gas valve, optional ignition/re-ignition device and gas bottle, Figure 11 shows a cross-sectional view of the gas nozzle and the position of the two ignition flame sensing electrodes when the present invention has an ignition/re-ignition system fitted to it, and Figure 12 shows an end view end view of the nozzle of the present invention of Figure 11 when mounted to the firebox wall.

The apparatus of the present invention consists of a gas nozzle retrofittable to a fireplace or provided installed in new fireplaces. The gas nozzle is preferably fitted to the back of a firebox, but may be fitted to other areas of the firebox. The nozzle is connected to a gas bottle or gas source and provides a flame directly to wood or appropriate burnable material within the firebox and a subsequent ignition of the wood or burnable material, thereby obviating the need for paper, kindling and matches to light a fire within the firebox.

Referring to Figures 1, 2 and 3, in the preferred form of the present invention a gas nozzle 1, preferably made of a ceramic type material is inserted into an aperture 2, preferably made into the back wall of a firebox 3. This aperture is preferably 30 mm in diameter and preferably drilled approximately 100 mm from the bottom and to the center of the firebox. The nozzle 1 is held against the aperture 2 in the firebox 3 by way of a bracket 4. The bracket 4 is preferably fastened within the firebox to the wall of the firebox by a thread and nut arrangement 5 (as shown in Figure 2) provided in the thermocouple 9, although the bracket may be fastened by any other appropriate fastening means. The bracket also provides shielding to the thermocouple 9 and electrode 11 from wood or other such material being thrown into the firebox that may cause damage to the electrode 11 and thermocouple 9. The nozzle 1 is of a tube like shape and has an inlet 6 (as shown in Figure 3) which is connected to a gas jet fitting 15 and then to an aluminum tube 7 to the gas valve, and an outlet 8 that is substantially against the aperture 2 in the wall of the firebox 3. The outlet 8 preferably has a diameter that is substantially less than the diameter of the aperture 2 in the wall of the firebox so as to allow a thermocouple 9, which is itself internal to the nozzle 1, and bracket 4 to be attached to the wall of the firebox within the remaining areas of the aperture.

The nozzle 1 has within it an aperture that is 8 mm in diameter, where a flame out probe or thermocouple 9 is inserted or threaded through. The thermocouple 9 has a function such that if the thermocouple detects a significant drop in the temperature, for example, the flame goes out, a message is communicated back to the gas valve via a copper pipe that has within it a standard electrical wire 10 to close the gas valve therefore preventing gas reaching the nozzle 1.

Referring now to Figure 3, within the gas jet fitting 15 is a small gas jet intake 13 allowing gas into the nozzle 1. The intake 13 is preferably approximately 1.15 mm in diameter. Furthermore, the gas jet fitting 15 is provided with preferably up to four air intake apertures 14 which preferably lie upstream of the gas flow and downstream of the gas intake end 6 of the nozzle.

The present apparatus is preferably provided to be retrofittable to the steel backing of a freestanding fireplace. It is therefore fitted with a right-angled gas fitting 15, as shown in Figures 1 and 3.

Alternatively, as shown in Figure 4, the apparatus of the present invention may be retrofittable to a brick fireplace 16 and is provided with a straight gas jet fitting 17. The use of a straight gas jet fitting 17 is preferable when the gas nozzle 1 is fitted to a brick lined fireplace. As different fireplaces have different thickness bricks, a right angle gas jet fitting 15 may not reach outside the fireplace. When fitting the apparatus of the present invention to a brick fireplace, a sufficiently sized hole is made in a brick and the nozzle is cemented in place within the brick.

Referring now to Figures 5 to 9, preferably the nozzle 1 includes an ignition electrode 11 that is connected to the piezo ignition switch 18 (or piezo electric generator), which is preferably mounted with the fail-safe gas valve preferably in the front panel of the pedestal 23 of the firebox 3, as shown in Figure 5. Alternatively, the piezo ignition switch and gas valve 18' may be mounted to the side of the pedestal to the rear of the firebox, as shown in Figure 6 and 9. Furthermore, the piezo ignition switch and gas valve 18" may be mounted to the top of the back wall of the firebox 3, as shown in Figures 7 and 8. The position of the piezo ignition switch and gas valve is dependant on the user's requirements. The connection from the ignition electrode 11 to the piezo ignition switch 18 is by way of a further standard electrical wire 12 (as shown in Figure 1). Where upon depression and turning of the gas valve and ignition switch 18 a spark is created between the ignition electrode 11 and the thermocouple 9 and a flame is formed in the nozzle and emits from the nozzle 1 and through the aperture 2, thereby lighting the wood or other such material within the firebox.

Referring now to Figure 10, a fail safe gas valve 18 is preferably provided with a piezo ignition switch, where once the user has opened the gas bottle outlet 22 and depressed the gas valve and piezo ignition switch 18, opening the safety valve, gas flows through the nozzle 1. As the switch 18 is rotated, it moves to an ignition point where a spark is formed between the electrode 11 and the thermocouple 9 igniting the gas within the nozzle 1. A flame is therefore emitted from the nozzle 1 igniting the wood within the firebox 3. One end of the gas valve and switch 18 is connected to the nozzle by way of an aluminum tube 7 as previously described, and the other end is connected to an approved gas hose 20, preferably made of a rubber material, which leads to a portable gas bottle 21.

Furthermore, within the gas valve 18 there may be provided a gas timer switch preferably fitted to the top of the gas valve 18. In this form the gas timer switch is depressed, and the gas valve opened, the switch is then rotated, the extent of the rotation determining the time in which the gas valve is open. Again, at a certain point in the initial rotation there is ignition prompting sparking on the electrode, igniting a flame. The timer switch then slowly returns, over a certain time, to its original position therefore closing the gas valve.

Referring now to Figure 10,11 and 12, the ignition apparatus of the present invention may be provided with an ignition/re-ignition system. This system, similar to that detailed in US 5857845 and well known in the art, is provided by two electrodes 25, as shown side-on in Figure 11 and end-on in Figure 12, as an alternative form of the ignition apparatus of the present invention. The two electrodes are powered by an ignition/re-ignition safety device 26 (as shown in Figure 10) that resides alongside the gas valve 18 and replaces the piezo ignition switch. The gas valve 18 and ignition/re-ignition device 26 are connected to one another by a standard electrical wire. When there is no flame emitted from the nozzle 1' and the electrodes are powered "on", a spark is provided across the electrodes. Upon opening the gas valve and providing a flow of gas 24 through the nozzle 1' the spark between the electrodes 25 ignites a flame at the nozzle outlet 8'. Furthermore, should the flame go out, the ignition/re-ignition safety device would register this and recommence the sparking across the electrodes 25 will re-ignite the flame. For additional clarity an end view of the nozzle 1' and bracket 4' is shown in Figure 12. The electrodes 25 protrude from the nozzle 1' into the internal area of the firebox 3' and preferably bend at opposing angles from one another outwards and upwards to the outlet of the nozzle 8'.

The apparatus of the present invention is positioned completely outside the firebox, and the wiring from the apparatus to the ignition switches and gas inlet valve may be placed under the firebox within the pedestal 23 (as shown in Figure 10) the apparatus of the present invention is mounted on or along the side of the firebox which allows for cooler running of the unit. Furthermore, the apparatus helps to prevent clogging of jets, manifolds or burners and as there are no manifold or burners to get in the way, cleaning of the firebox is extremely easy. Also, due to no manifold or burners being inside the firebox there is more area for fire wood in the firebox.

The use of gas to ignite combustible material is favourable because of the speed in which material is ignited. The apparatus of the present invention is self cleaning, clean in nature, and no paper, kindling, matches or hand held lighters are required, therefore there is no human contact with heat or flame. Also start up emissions are greatly reduced when gas is used to ignite wood, wood pellets or coal. By starting the system approximately two minutes prior to adding a combustible material the firebox and flue are sufficiently heated to create a draw through the firebox, which greatly assists in reducing ignition time, further lowering harmful start-up emissions.

Claims (21)

WHAT I CLAIM IS:

1. A solid fuel ignition means securable to the outside of a firebox comprising or including: a gas nozzle, having a combustion chamber, an inlet and an outlet, a gas source, a gas valve, a conduit connecting said gas source to said gas valve, said gas valve being connected to the inlet of said nozzle by a second conduit, wherein said nozzle is adapted to be secured to a wall of said firebox such that the flame projected through the outlet of said gas nozzle can pass through an aperture in said wall of said firebox to impinge on said solid fuel within said firebox.

2. A solid fuel ignition means according to claim 1 wherein said ignition means further includes a sparking means associated with said nozzle, for the ignition of gas within said combustion chamber of said nozzle.

3. A solid fuel ignition means according to claim 2 wherein said sparking means includes is a piezo igniter which is energised by a remotely located switch and at least one electrode connected by way of a conduit to said piezo igniter.

4. A solid fuel ignition means according to claim 3 wherein said at least one electrode is mounted within said combustion chamber.

5. A solid fuel ignition means according to claim 3 wherein said at least one electrode is mounted at the outlet to said combustion chamber.

6. A solid fuel ignition means according to any one of claims 1 to 5 wherein said ignition means further includes a heat detecting probe positioned proximate to said combustion chamber.

7. A solid fuel ignition means according to claim 6 wherein said heat detecting probe is provided above said nozzle and protrudes through said wall of said firebox.

8. A solid fuel ignition means according to either of claims 6 or 7 wherein said heat detecting probe controls the gas valve such that if the thermocouple detects a significant drop in temperature the gas valve is closed to prevent gas reaching said nozzle.

9. A solid fuel ignition means according to any one of claims 6 to 8 wherein said heat detecting probe is a thermocouple.

10. A solid fuel ignition means according to any one of claims 1 to 9 wherein an air intake is provided upstream of the direction of the gas flow to said combustion chamber.

11. A solid fuel ignition means according to claim 10 wherein said air intake is at least one aperture in the wall of said inlet to said nozzle.

12. A solid fuel ignition means according to any one of claims 1 to 11 wherein said - 10- nozzle is made of a ceramic material.

13. A solid fuel ignition means according to any one of claims 1 to 11 wherein said wall of said firebox is the back wall of said firebox.

14. A firebox including an ignition means according to any one of claims 1 to 13 mounted on the outside of said firebox.

15. A method of providing enhanced ignition of solid fuel within a firebox, said method comprising the steps of: (1) providing within the wall of the firebox an aperture, (2) fitting the outlet of a gas nozzle to said aperture, (3) connecting to the inlet of said gas nozzle to said gas valve by was of a first conduit, (4) connecting said gas valve to said gas source by was of a second conduit, wherein upon depression and turning of said gas valve by a user, a flame is ignited in said nozzle, said flame impinging on said solid fuel within said firebox and lighting said

16. A method of providing enhanced ignition of solid fuel within a firebox according to claim 15, wherein said nozzle has an aperture, said method including the step of fitting a heat detecting probe to said nozzle aperture.

17. A method of providing enhanced ignition of solid fuel within a firebox according to claim 16, said method including the step of connecting said heat detecting means to said sparking means by way of a third conduit.

18. A method of providing enhanced ignition of solid fuel within a firebox according to any one of claims 15 or 17, said method including the step of mounting a sparking means to said firebox.

19. A method of providing enhanced ignition of solid fuel within a firebox according to any one of claims 15 to 18, said method including the step of mounting an ignition electrode within the flow of gas within said nozzle.

20. A method of providing enhanced ignition of solid fuel within a firebox according to claim 19, said method including the step of connecting said sparking means to said ignition electrode by way of a third conduit, allowing in use, ignition of said gas in said nozzle, by initiation of said sparking means.

21. A combustible material ignition means as herein described with reference to any one or more of the accompanying drawings. fuel. Intellectual Property Office of NZ - 5 SEP 2000 RECEIVED