Igniter Facility

Abstract

A main gas burner has a plurality of parallel rows of individual burners. An igniter burner tube extends normal to said rows and has an igniter flame port at each of said rows. An electrical igniter is at one end of the igniter tube to commence the propagation of flame and an electronic flame detector is at the other end of the tube. Controls are provided between the detector and the gas valves for the burners.

Description

BACKGROUND AND SUMMARY OF THE INVENTION

A fail-safe ignition is a requisite for the burners of gas-heated appliances such as water heaters and space heaters. The fail-safe apparatus may include a bimetallic strip or a thermoelectric device heated by a continuously burning pilot flame. When gas is supplied to the main burner, the pilot flame ignites the same. The consumption of gas at ignition by devices of this kind is required to be very reduced, but progressive ignition of the main burner is facilitated by a very elongated ignition flame or by a number of ignition flames evolved at the pilot burner. Nevertheless, progressive ignition from one burner unit of the main burner to the next produces disturbing noises which the known pilot facilities cannot reduce satisfactorily.

Gas-heated appliances having electrically ignited and electronically detected burners are known. They require no continuous pilot light, since the burner is reignited at each start by an electric spark produced by an igniter electrode and burner operation is detected electronically. Since the electric ignition ignites only those burner flames which are very near the igniter electrode, the other units of the burner ignite by progressive ignition and progressive ignition over the whole burner still remains unsatisfactory. The larger the main burner the greater becomes the ignition noise because of the increased delay in progressive ignition.

It is an object of the invention to devise an igniter which obviates these progressive ignition problems in electronically controlled burners.

According to the invention, the igniter is an igniter tube which extends across all the burner units and which has an ignition aperture near each unit of the main burner.

In a facility according to the invention, when the igniter tube is "on" and gas commences issuing from the main burner, all the burner units or individual burners of the main burner are ignited simultaneously, thus obviating the unsatisfactory delay associated with progressive ignition from one individual burner to the next.

Advantageously, in the case of a lattice type burner comprising a distribution tube and a number of parallel individual burners perpendicular to the tube, the igniter tube extends along the distribution tube. In the case of burners where the gas is first supplied at one end of the burners immediately following the gas being turned on, the igniter tube is put at that end of the burners. Consequently, in addition to all the individual burners igniting simultaneously, any individual burner is ignited at the orifices which are nearest the igniter tube and which are the first orifices to deliver gas at start-up, the flame then spreading very rapidly along each individual burner.

According to another feature of the invention, an electric igniter electrode is positioned at one end of the igniter tube and a detector electrode of the electronic flame detector is at the other end. In this case, the electronic flame detector indicates a flame only if there has been propagation of the igniter flame starting from the igniter-electrode end of the igniter tube and continuing to the other end, so that an igniting flame is "on" over the whole length of the igniter tube, ensuring uniform ignition of the main burner.

DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation of an appliance burner apparatus and associated igniter, the appliance burner comprising a number of individual burner units;

FIG. 2 is a plan view of the burner apparatus shown in FIG. 1;

FIG. 3 is a side elevation of a lattice type burner apparatus and associated igniter; and

FIG. 4 is a plan view of the burner apparatus shown in FIG. 3.

DESCRIPTION OF SPECIFIC EMBODIMENTS

The following disclosure is offered for public dissemination in return for the grant of a patent. Although it is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by variations in form or additions or further improvements. The claims at the end hereof are intended as the chief aid toward this purpose, as it is these that meet the requirement of pointing out the parts, improvements, or combinations in which the inventive concepts are found.

The burner apparatus shown in FIGS. 1 and 2 comprises a number of individual burner units 1 to which gas is supplied from pipe 13 through nozzles 2. Primary air is aspirated through nozzles 2 by the gas flow. Each of the main burner units 1 are formed (in a known fashion) by two sheet-metal shells 3 joined together by seams 3'. At the top of shells 3 an outlet plate 4 covers the resulting burner mixing chamber. The gas-air mixture issues from the mixing chamber through orifices 4' in plate 4 to form the burner flames when ignited. A plurality of units 1 are positioned in parallel rows so that there are separate rows of ports 4' from which the flames emanate. This general type of burner is shown in greater detail in U.S. Pat. No. 3,288,196 of Nov. 29, 1966.

At the burner ends 1' remote from the nozzles 2 is an igniter tube 5. Tube 5 has a number of orifices 5' positioned so that inclined igniting flames 5" are produced. Gas is supplied to the burner apparatus via connection 6. After a valve 7 operated by a solenoid 7' has opened, gas proceeds to burner tube 5 through ignition line 8 and mixer 9. This is a form of a bunsen burner having gas nozzle which aspirates primary air in through orifices 9' in mixing tube 9. Once valve 10 is opened by solenoid 10', gas enters the main burner through conduits 11 and 13. From conduit 13 the gas proceeds through the nozzles 2 into the individual burner units 1.

As can be gathered from FIG. 2, an igniter electrode 14 of an electric igniter is positioned at one end of tube 5. To start the burner (for instance, when a room thermostat demands heat in the case of a circulating water heater) an electric circuit is closed to energize solenoid 7' and open valve 7. Gas issues from igniter tube 5 and is ignited by a spark from electrode 14. ONce the flames 5" have ignited for the full length of tube 5, detector electrode 15 actuates control means 10" to energize solenoid 10' and open solenoid valve 10. Thereupon, gas issues from main burner units 1 for ignition by igniter 5.

The individual burners 1 of the main burner are ignited simultaneously at all the ends 1' adjacent the igniter. With the type of burner unit shown in FIG. 1, the gas-air mixture initially issues at the ends 1'. Since the igniter flames 5" are at the point where the first gas comes out of the burner units, the flames progressively propagate the length of the burner unit as the mixture commences emanating from the slots 4' along the length of the unit.

Control means 7" includes suitable time sensing apparatus to determine whether a flame is detected by electrode 15 within a given period of time after solenoid 7' is energized to open valve 7. If flame is not detected by electrode 15 within that time, control means 7" deenergizes solenoid 7' to close valve 7. Thus, if (upon valve 7 being opened) flame does not develop at igniter electrode 14, or if that flame fails to propagate the length of tube 5, valve 7 will be closed as a safety measure.

FIGS 3 and 4 illustrate a lattice type burner. It has a plurality of burner units in the form of tubes 17. These have openings in the top from which the gas-air mixture flows to form the flames seen in FIG. 3. This mixture flows to the tubes from distribution tube 16 upon valves 7 and 10 being opened (as previously described). While the igniter tube 5 can be at one end, it is better to have it immediately opposite the distribution tube 16, as shown in dotted lines, designated 5a, in these views. Here it is formed with two rows of outwardly inclined ignition flame rows 18, 18', so that the distance to the flame rows to be ignited on both sides of the igniter are relatively short. The initial gas flow from the ports in tubes 17 will be immediately adjacent distribution tube 16 and igniter tube 5a. Thus, there will be an even flame propagation when the valves are opened. Of course, the igniter 14a and the detector 15a are positioned at opposite ends of igniter tube 5a.

Claims

We claim:

1. In a gas burner apparatus for use with a source of combustible gas and having a plurality of spaced rows of ports from which a combustible gas is emitted to be burned and an ignition device for said gas, said device including an igniter tube extending transversely across said rows and adapted to be connected to said source so that said combustible gas is supplied thereto, said device having a plurality of ignition flame apertures from which said gas can exit to produce ignition flames which apertures are positioned so that a respective one of said ignition flames will be adjacent each row to supply flame propagation from each respective flame to each row, said ignition apertures being sufficiently close together that the flame will propagate from one ignition flame to the next, the improvement comprising:

said device including igniter means positioned adjacent one end of said tube for commencing said propagation of flame; and

flame detector means at the other end of said tube for determining if the flame has propagated the length of the tube.

2. In an apparatus (a) of the type including a normally closed gas valve to control the flow of gas to said ports with operating means on the valve to open the valve and permit the gas to reach said ports and (b) as set forth in claim 1.

wherein said apparatus includes control means connecting said detector means and said operating means for opening said valve after said detector means has determined that the flame has propagated the length of the tube.

3. In an apparatus (a) of the type including a second normally closed gas valve to control the flow of gas to said tube with operating means for said second valve to actuate the second valve and open it to permit the gas to reach said apertures and (b) as set forth in claim 2.

wherein aid apparatus includes control means connecting said detector means and the operating means for the second valve to deactuate said operating means therefor if the detector means has not sensed the propagation of flame within a given period after the operating means for the second valve was actuated to open said second valve.

4. In an apparatus (a) as set forth in claim 3, and (b) including a main distribution tube having a plurality of cross tubes in lattice form with said ports in said cross tubes,

wherein said igniter tube extends along the distribution tube and parallel thereto.

5. In an apparatus (a) of the type such that upon the initial supply of gas the emission of the gas from the rows commences at one point along the length of the rows and (b) as set forth in claim 3, wherein said igniter tube is positioned adjacent said one point of said rows.

6. In an apparatus (a) as set forth in claim 1, and (b) including a main distribution tube having a plurality of cross tubes in lattice form with said ports in said cross tubes,

wherein said igniter tube extends along the distribution tube and parallel thereto.

7. In an apparatus (a) of the type such that upon the initial supply of gas the emission of the gas from the rows commences at one point along the length of the rows and (b) as set forth in claim 1, wherein said igniter tube is positioned adjacent said one point of said rows.