US3122195A

US3122195A - Pilot shield for gas heater pilot burners

Info

Publication number: US3122195A
Application number: US45714A
Authority: US
Inventors: Merl J Kimmel; Harry E Thompson
Original assignee: OHIO FOUNDRY AND Manufacturing CO
Current assignee: OHIO FOUNDRY AND Manufacturing CO
Priority date: 1960-07-27
Filing date: 1960-07-27
Publication date: 1964-02-25
Anticipated expiration: 1981-02-25

Description

Feb. 25, 1964 M. J. KIMMEL ETAI. 3,122,195

PILOT sump FOR GAS HEATER PILOT BURNERS Filed July 27, 1960 2 Sheets-Sheet 1 Feb. 25, 1964 M. J. KIMMEL ETAL PILOT SHIELD FOR GAS HEATER PILOT BURNERS 2 Sheets-Sheet 2 Filed July 27, 1960 United States Patent Ofifice 3,122,195 Patented Feb. 25, 1954 3,122,195 PFJLQT SHIRE) FOR GAS HEATER PILOT BURNERS Merl .l. Kirnmel and Harry E. Thompson, Steuoenville, Ohio, assignors to The Ohio Foundry & Manufacturing Company, Steuhenviiie, Ohio, a corporation of Ohio .luiy 27, 1960, Ser. No. 45,714

4 (Ilaims. (Cl. 1587) This invention relates to a shield for the pilot flame of a gas burner, more particularly for use with space heaters of the so-called sealed combustion system type where the combustion chamber fully encloses the burner and pilot and only otherwise has communication with a combustion air inlet and an exhaust flue.

Although a combustible gas whether natural or artificial is normally distributed for use in burners at a substantially uniform pressure, nevertheless, many conditions aside from possible fluctuation of such pressure may cause the pilot lig t to be extinguished. Often re-lighting under present circumstances requires the assistance of a skilled service man. Therefore, the stability of the pilot flame is important. In sealed combustion systems, where the pilot burner is exposed, high wind conditions for example, velocities up to fifty miles per hour, make it extremely difficult to light a pilot because it is necessary to open a pilot access door or a peep hole to do so. This disturbs the balance of pressure in the sealed chamber because air can blow out through the opening of whatever type it might be, making it diflicult to re-light the pilot. In many cases the outside venting device of a sealed combustion system must be blocked ofi in order to re-light the pilot. Also, other conditions such as updraft, down-draft, freak winds and the fluctuation of burner operation due to turning the gas on and off affect pilot flame stability.

Accordingly, a primary object of the present invention is to provide a construction which will provide assurance of maximum flame stability under varying operating conditions over which the user has no control, and if the pilot should go out, makes it easier to re-light.

Another object of the invention is to provide a device with a suitable pilot flame shield applicable to any type of gas heatin equipment where a pilot flame is used.

A further object is to provide a pilot flame shield which retains its incandescence and prevents fluctuations of the pilot flame under such varying wind and pressure conditions. The incandescence assists in supporting combustion even though wind is directed against the pilot shield for an extended period of time. This incandescence of the shield is important.

A further object of the invention is to provide a pilot flame shield with a plurality of openings whose relationship to the pilot burner and main burner are such that they permit lighting or re-lighting of the pilot burner from the inside, while the shield can be also readily used from the outside as well as lighting the main burner with slight variation in design with various types of thermocouples and pilot burner designs.

A still further object is to provide an assembly wherein the shield is maintained in proper relationship to the pilot burner by a mounting bracket secured to the burner body. By placing the shield over the pilot burner and locating it in positive relationship thereto, the desirable features sought by the present invention are achieved.

With the above and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel construction, combination, and arrangement of parts, hereinafter more fully described, illustrated and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings in which:

FIGURE 1 is a perspective view of a typical burner and pilot installation in accordance with the present invention.

FIGURE 2 is a front elevation of the construction shown in FIGURE 1 with the front portion of the shield broken away to show the opening in the rear wall of the shield.

FIGURE 3 is an end elevation of the construction shown in FIGURE 1.

FIGURE 4 is a composite View of the shield supporting parts showing in perspective the plate having a tongue interlocking with the shield and the bracket both for connection to the burner proper.

FIGURE 5 is a detail perspective view of the unit including the shield and the support.

FIGURE 6 is a detail perspective view of a modified form of support for the shield wherein the latter is detachably connected to the support.

Similar reference characters designate corresponding parts throughout the several figures of the drawings.

The burner proper is designated generally as A and includes the burner head B having flame outlets which communicate through the throat portion C with a gas and air mixing inlet chamber D. The burner assembly described may be placed within a compartment or chamber having a rear wall 1r and a front wall 11 formed with mating flange sections 3 to be secured together to define a sealed combustion chamber. The rear wall 1r is provided with a suitable air inlet 4 and the upper end of the sealed combustion chamber 2 is connected with an exhaust flue, not shown. The front wall 1] of the sealed combustion chamber is equipped with a detachable door 5 releasably held in place by the bolt and

wing nut arrangement

6, 7, which compress a suitable gasket for sealing.

The pilot burner assembly is supported at the door or peep hole side of the main burner A and includes a pilot burner 8 communicating with a source of gas supply through a pipe 9 including a control valve, not shown, responsive to a thermocouple ill disposed in a position to be subjected to the heat of the pilot flame in order to keep open the gas valve leading to the inlet pipe 9 as long as the pilot is lit. If the pilot goes out, the thermocouple 10 reacts to close the valve to the pilot, thereby necessitating relighting of the pilot. The type of thermocouple shown is chosen by way of example and the invention is intended to apply to an installation where the thermocouple is separate from the pilot burner itself or made as a part thereof. The point is that it is preferable to enclose the pilot burner and thermocouple in the same flame shield S.

One of the distinctive features of the present invention is the provision of the aforesaid pilot flame shield S which in the example shown is of tubular elongated rectangular construction. This shield S is foraminous and may be made from perforated stainless steel sheet or stainless steel wire mesh. In all cases the shield has a plurality of open ings. For example as shown, it has a front wall 11 with an opening 11 adjacent the mouth of pilot 8 to permit of the insertion of a match or taper for re-lighting. Also, the rear wall 12 of the shield is provided with an opening 13 so that the pilot flame may readily ignite gas issuing from the main burner head B to re-light the burner.

In addition to the opposite openings 11 and 13, the end Wall 14 of the shield is also preferably provided with an opening 14 to facilitate ignition of the pilot flame while the mouth of pilot 8 is always shielded from unstable air. Opening 14 provides a second pilot ignition opening.

By way of adapting the pilot shield to a typical burner.

it is intended to provide the shield S with a support whose main parts for example, are shown in detail in FIGURE 4, and as they are assembled in FIGURES 1, 2 and 3.

Where it is desirable to provide for a readily renewable shield, it is possible to detachably fit the lower end thereof onto the back plate 16. The wall portion has openings 17 and whose upper edge 18 is bent inwardly and upwardly to provide in cooperation with an adjacent face 1 of the burner body, a shield engaging and centering tongue 18. As will be seen more particularly from FIGURE 3, the tongue i8 is inwardly ofiset relative to the body 16 and spaced from the adjacent Wall portion f of the burner B to provide therebetween, in effect, a slot to receive and frictionally grip the lower edge of the rear wall 12. When this occurs, the lower edges of the three side walls 13, 14- and 15 will rest upon the upper wall or leaf 19 of the attaching and supporting bracket designated generally as 29, and which includes in addition to the horizontal shelflike leaf 19, a vertical web 23 provided with at least one elongated opening 22, and a second opening 22 intended to register with the openings 17 to receive the fastenings 23 (FIGS. 1 and 2) to secure the back plate and bracket to the adjacent side face 1 of the burner. Bracket 29 also includes a lower wall or leaf or offset ear 26.

The upper shelf 1? of the bracket 26 is provided with spaced

openings

24 and 25 to permit the admission respectively of the thermocouple 1i and pilot 8. The lower shelf or ear 25 is cut away beneath opening 25. The remaining part of car 26 is provided with a single opening 27 registering vertically with opening 24. The usual lock nuts are provided adjacent 27 on the termocouple to maintain the latter in proper relation to the pilot 3.

As shown in FIGURE 5, the shield S and its primary support 16 are permanently connected by the welds W to provide an assembly that may be handled as a unit.

FIGURE 6 is the perspective view of a modified form of bracket Zii wherein the shelf-like leaf 19 is formed with fingers or prongs 18 offset inwardly from the four horizontal edges of the leaf 19 to detachably and telescopically receive the lower portion of the screen S. The lower edge of the screen S when fitted over and about the prongs rests on the four side edge portions of the leaf 19 while the prongs or fingers 18 are frictionally engaged within the bottom of the shield.

From the foregoing, it will now be seen that the pilot flame shield assembly includes the foraminous shield S and a suitable support. In FIGURES 2 and 5, this support is the plate 16 while in FIGURE 6 the support is the shelflike portion of the pilot burner bracket such as 20 in FIG- URE 2.

Moreover, it will be understood that whether the pilot shield S is made of perforated sheet metal or fine mesh, the openings in the walls thereof for both lighting the pilot and lighting the burner are arranged so that the shield is adaptable to a reasonably wide range of pilot burners. The fact that the fine mesh becomes incandescent also provides forgreater stability of the pilot under all conditions in which it must operate.

We claim:

1. In a gas heating device including a sealed combustion chamber,

a main burner and a pilot burner with a horizontally directed tip therewithin,

a vertically elongated transversely hollow multiple walled perforate member of constant transverse horizontal cross section and having pairs of parallel walls and open at both ends,

one pair of its vertical walls provided with at least one central opening many times larger in area than the area of each of the remaining openings of the perforate member,

said'one central opening and the tip of the pilot burner being proximate to each other and approximately mutually aligned,

whereby the edges of the opening are maintained during normal operation in a heated condition,

and means closing only the lower open end of the perforate member and mounting the member on said burner,

and whereby the pilot burner is shielded and is provided with an access opening through the perforate member for relighting the pilot burner.

2. In a pilot light structure, a pilot burner with a horizontally directed tip,

a multiple walled shield member substantially uniformly perforate throughout the major area portions of each wall, to be used for enclosing at least the horizontally directed end of the tip of the pilot light and the continuously burning and substantially horizontally directed flame of the pilot light for a main burner of a gas heating device,

said shield per se being formed as a vertically elongated transversely hollow structure of identical transverse cross section configuration throughout its vertical extent and completely open at both ends,

and having at least one of its vertical walls provided with a substantially central coplanar edged opening many times larger in area than each of the other perforations,

the opening being proximate to and approximately aligned with the level or" the tip of the pilot burner,

whereby edges of the opening are maintained during normal operation in a heated condition,

and a support member including a functionally imperforate horizontal shelf, contacting and aligned with one end of the shield and including a portion adapted to be attached to a main burner.

3. The structure of claim 2 wherein the support member also includes as alignment means,

a plurality of vertically extended prongs each offset inwardly from the perimeter of a horizontal portion of the support member,

each prong contacting a bottom portion of the adjacent Walls of the shield to thus telescopically and detachably receive the lower portion of the shield.

4. The structure of claim 2 wherein the support member includes a flat vertical back plate with spaced openings through its lower portion, with an integral medial horizontal otiset, and an integral vertical fiat top-tongue,

the tongue being thin and tall as compared to its thickness, and telescoped within the end of and extending substantially the horizontal extent of one of the vertical shield walls,

whereby by flat or planar contact of tongue and shield, the shield member may be held towards a main burner;

and wherein the shield member is constructed of such size as to be capable of also enclosing a thermocouple;

and wherein further the support member includes a bracket which is formed with an upper horizontal, fiat, leaf which contacts the shield and guides the pilot tip and a portion of the thermocouple,

an integral leaf-adjacent flat vertical web with spaced slot means therein, the web being in contact with the base of the back plate and the slot means aligned with the spaced openings of the back plate, whereby each slot and opening may mutually carry on attachment means to a main burner,

the support member including an integral web-adjacent, lower, horizontal, flat ear below a portion of the length of the upper leaf to guide another portion of the thermocouple.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Jacob July 9, 1889 Southworth Nov. 30, 1915 5 Hicks May 8, 1928 Matson Mar. 19, 1935 Krogh Aug. 25, 1936 Wantz Nov. 28, 1939 Shipley et a1 May 18, 1943 Martin June 15, 1948 West Feb. 23, 1952 Betz July 11, 1961 FOREIGN PATENTS Great Britain Apr. 26, 1938

Claims

1. IN A GAS HEATING DEVICE INCLUDING A SEALED COMBUSTION CHAMBER, A MAIN BURNER AND A PILOT BURNER WITH A HORIZONTALLY DIRECTED TIP THEREWITHIN, A VERTICALLY ELONGATED TRANSVERSELY HOLLOW MULTIPLE WALLED PERFORATE MEMBER OF CONSTANT TRANSVERSE HORIZONTAL CROSS SECTION AND HAVING PAIRS OF PARALLEL WALLS AND OPEN AT BOTH ENDS, ONE PAIR OF ITS VERTICAL WALLS PROVIDED WITH AT LEAST ONE CENTRAL OPENING MANY TIMES LARGER IN AREA THAN THE AREA OF EACH OF THE REMAINING OPENINGS OF THE PERFORATE MEMBER,