US2808878A - Gas burner - Google Patents

Description

W. P. AYERS GAS BURNER Oct. 8, 1957 Filed Jan. 25, 1951 3 Sheets-Sheet 1 .IEZEHZQ: WILL/AM P. AYE/2s W. P. AYERS Oct. 8, 1957 GAS BURNER 3 Sheets-Sheet 2 Filed Jan. 25. 1951 W. P. AYERS GAS BURNER Oct. 8, 1957 3 Sheets-Sheet 3 Filed Jan. 25, 1951 Wm IAN P. A r5125 United States Patent G GAS BURNER William P. Ayers, Lombard, 11]. Application January 25, 1951, Serial No. 207,752

1 Claim. (Cl. 158104) This invention relates to improvements in gas burners of the type for use with furnaces, -boilers,.and the like.

The gas burner of this invention is of unitary construction, easily applied or mounted in a furnace or boiler and requiring connection only to a fuel supply line for operation. Generally, the 'burner construction provides a housing or windbox within which is mounted a mixing tube for supplying combustion fuel. to -a series of refractory radiant burners; a series of walls within the housing for controlling and directing secondary air around the burners in such a way as to confine the burner flames to heating the radiating surfaces of the radiant burners and away from the housing thereby providing for maximum combustion and higher heating and radiating efliciency; adjustable air inlet openings for the control of both the primary and secondary air supply; a gas control system providing automatic regulation of the burner in accordance with temperature requirements and a safety shutoff in the event of a failure of the pilot flame; and, a remote control pilot lighter.

It is, therefore, an object of this invention to provide a gas burner having an extremely high heating and radiating efiiciency.

A further object of the invention is the provision in a gas burner of a housing so shaped and constructed as to provide for the regulation and control of primary and secondary air supplied to the burner.

Yet another object of the invention is the provision in a gas burner of a housing constructed to provide separate channels for the supply of air to the main burners and to a pilot burner.

A still further object of this invention is the provision of a gas burner in which air supplied to the burners is so controlled as to effect a uniform flow thereof over the entire burner area and so directed as to confine the burner flames to heating radiating surfaces.

Another and still further object of the invention is the provision in a gas burner of a housing having adjustable air inlet openings for regulating the supply of air to the interior thereof.

Still another and further object of the invention is the provision of a gas burner that is positive in ignition and safe in operation.

Other and further objects of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment of the invention as disclosed in the annexed sheets of drawings, in which:

Figure 1 is a side view in elevation of the gas burner embodying principles of this invention;

Figure 2 is a top plan view of the burner shown in Figure l; V

Figure 3 is a longitudinal vertical cross-sectional view, with parts in elevation, taken substantially along a plane indicated by the line 33 of Figure 2 and showing the internal construction of the burner;

Figure 4 is a transverse vertical cross-sectional view,

with parts in elevation, taken substantially along a plane indicated by the line 4-4 of Figure 3;

Figure 5 is an enlarged-fragmentary elevational view of the bottom of the burner housing as seen when viewed at the extreme right end of Figure 3;

'Figure 6 is an enlarged fragmentary top plan view of a mixing tube, with an end portion broken away to illustrate the fuel feed connection, shown previously in side elevation at the bottom of the burner housing in Figure 3;

Figure 7 is a side view in elevation of the mixing tube on which is illustrated the connection or locking arrangement of refractory radiant burners thereto;

Figure 8 is an end view in elevation of the mixing tube as seen when viewed from the right;

Figure 9 is a fragmentary side view in elevation of a modified form of the locking portions by which the refractory radiant burners are connected to the mixing tube; and,

Figure 10 is a view diagrammatically illustrating the mixing of air and fuel in the mixing tube.

As best shown in Figures 1, 2 and 3, the gas burner device 10 of this invention generally comprises a housing or windbox 11 within which is located a manifold or mixing tube 12 for supplying fuel to a series of radiant burners 13, a fuel control system 14, and a pilot burner and lighter device 15.

The housing or wind-box is a U-shaped shell having one end 16 closed and its opposite end open. A top wall 17, of shallow inverted U-shape, extends from a point spaced from the open end of the housing to a point just beyondits center where it terminates in a downwardly directed and rearwardly extending firewall 18 with its end 19 just resting on and curved upwardly from the mixing tube 12.

As seen in Figures 2 and 3, which is the preferable form, the mixing tube 12 is positioned at the bottom of the housing longitudinally along the center thereof. The tube is preferably of rectangular :or square section and tapers upwardly toward its forward end, for purposes to be more fully explained hereinafter. The bottom wall 20, defining the tapered section of the tube, rests on a baflie wall 21 in the housing which wall slopes forwardly from an intermediate line on the end wall 16 to the 'bottom of the housing.

It will be noted that the sloping walls of the tube and housing extend lengthwise of the housing below the same area occupied by the radiant burners 13. It is to be understood, however, that while a sloping 'wall 21 is desirable it is not necessary although it will be apparent hereinafter that its use does increase the efficiency of operation of the device.

A saddle clamp 22, extending over the mixing tube and secured to the bottom wall of the housing, secures the tube thereto. The crimped, upturned end 23 of the tube is secured to the end wall 16 which, together with the saddle clamp, firmly anchors the mixing tube in the housing.

At the tapered end of the mixing tube is located a series of radiant burners 13. In Figures 6 and 7 there is illustrated the connection of the hollow burners to the mixing tube. The top surface of the tube is perforated or punched spaced fuel feed openings 24. Metal displaced by the punching operation effects a flared edge 25 around each opening. A refractory radiant burner, having a hollow base 26, is positioned over each fuel opening and anchored to the mixing tube by sealing the space around the flared edge 25 and the'adjacent inner surfaces of the burner base with a ceramic cement 27.

A detailed description of the radiant burners is not given herein as the independent construction thereof forms no part of this invention. La-terally extending fuel jet outwardly to provide a plurality of' 3 openings 28 connect the interior oi the hollow base of each burner with the vertical exterior side surface thereof where emerging fuel burns with a flame.

,dni Figure 9, is r'ilustrated. a modified embodiment of the anchoring construction onthe mixing tube for tihei burners; Itr this embodiment, the fuelopenings are punched outwardly to form nipples 29, 29' the: outer-sun faces of which are roughened or knurled as'at: 301'to. for-m. numerous grooves and undercutuedges for holding the ceramic cement.

.At the end of the mixing tube opposite its tapered end, there is provided: fuel supply inlets. Spaced inwardly fromthe closed end of the tube is an; opening 31-; in: the bottom wall which registers. with: a, bendable tab? 3 2' in the bottom of the burner housing (see Figures 3" and 5.) the functions of which; will; bedescribed hereinafter. An axial opening 33, in'tlieendwall'of the mixing:tube receives therein an en'dwi'se adjustable: fuel; jet or nozzle orifice 34; The jet threads into a T-connection 3S whereby it may be axially adjusted sothat the tapered end 36 is positioned in the opening 33. A removable threaded plug 37 provides: access to the interior? of: the T-connection for cleaning purposes and seals an opening which otherwise may be used either for. an. additional fuel supply line or for testing the pressure of gas at the jet or nozzle 34;

The T-connection has a nipple portion 38 threadedly connected to a reducer 39'. The reducer in turnthreadedly engages with the outlet side (not shown) of: the gas control valve 40, the inlet side of which is shown in Figures 1 and 3 connectedv to the main. fuel line 41. The valve is anchored to the bottom wall of the housing by means of astudv 40a.

The gas control valve and the pilot generator neonstruction illustrated herein. are: not independently a part of the novelty of this application,- both being, well-known in the art. However, the relationship and location'of the pilot generator with respect to the radiant burners and certain portions of the housing are important to the safeand eflicient operation of the burner described herein; Generally, the pilot generator utilizes the principle of the thermocouple to produce an electric current required for the operation of the gas control system- The pilot generator extends through and restson the bottom edge of an oversize opening 43 in thesloping firewall I8 and the generator flame applied to the hot junctions 44 of the thermocouple also serves as the main burner pilot to ignite the jets of the radiant burners, If for anyre'ason the ilot burner were extinguished, the electriccurrent produced would cease and the gas control valvethereby would automatically be operated to a closed position cut ting off the supply of fuel through the mixing tube to the radiant burners.

As shown in Figures 2 and 3, the hot junction end 44 of the pilot generator 42' terminates and is located in the space between the firewall 1'8 and the nearest or adjacent radiant burner 13. In this position, the thermo couple junctions 44 are above the fuel jet openings 28 which. face the space between the firewall and the ad"- jacent radiant burner.

The gas control valve is operated by the current developed 'by the pilot generator in response to demands of aroom thermostat 45.- Generated current'fiowing through wiring 4'6 actuates' a n armature which controls the opening and closing of the' gas control valve either allowing or preventing theflow of gas tothe'main burner; As" inlet. gas. pressure is utilized in this type of control valve for actuation. thereof, a vent 47 is provided tobleed the chamber above the: valvewhen the-valve is actuated to anopen-position.

Fuel from the main supply line to the pilot generator flows through the pipe lines 48 and 49. The automatic shut-chi of the main burner fuel supply by the control valve 40 does not shut off the'pilot generator supply. If desired, this may be ac'coniplishedby the installation iii 4 the pipe line. 48 either of a control valve similar to valve. 40 or to a manually operated-shutoff valve.

Extending in a direction opposite to the line 49 and connected thereto for the flow of fuel, is another line 50 which terminates in a valve 51. This valve has a push-button control 52 and a nozzle 53 extending therefrom in a forwardly directions As fuel under pressure is constantly available in the line 50, a stream of fuel is ejected when the push hut'ton cont rol is depressed. The fuel stream travels forwardly alonga pathdefined by an inverted channel or U-shaped" member 54 carried on the underside otthe tbp wall-Hot the'housin'g. Theirear end 55 of the member 54 is spaced forwardly of the nozzle 53 with an opening 56 located therebetween in the top wall of the housing. The other end 57 of the member 54 terminates in a firewall opening 58 located in closely spaced relation laterally of the opening through which the pilotgenerator extends. l

The operation of the burner will now be described;

To light thepiiot generator, the pushabutton. control 52 is depressed: whereby a strearnof gas is ejected from the nozzle 53 along. and within the member 54. A. light is then held at the opening, 56 thereby igniting the gas stream and the flame travels to the end of thepilotlighter through the firewall. adjacent. to the pilot generator. Gas

flowing through the pipe line 49 and generator 42 ignites" as it emerges atthe hot junction. end. Current developed by heating the hot junctions of. the thermocouples together with gas pressure at the inlet side of the gas control valve effect an openinguof the valve in response to therequirementsofi the room thermostat. Whenactuated to an open: position, the valve supplies fuel. to themixingtubelZ.

In Figure 1-0 is diagrammatically illustrated the autotnatic mixing of the gas and primary air in themix ing tube 12. By bending. the flap 32 downwardly from the bottom of the housing, the air inlet-opening registering with the: opening 31. in the mixing tube is adjusted to effect a flow of air necessary to mix with the gas and provide a combustible mixture to the radiant burn'ers-r The air opening. is increased as the tab is depressed.

The stream of, gas emerging under pressure from the jet or nozzle tip 34 is directed axially lengthwise ot the mixing burner in an area generally defined at 59' inFigme 10. As it progresses along the tube it expands radially and mixeswiththe entering, through the primary air inlet. During the travel of the air and. gas lengthwise of. the mixing tube, the square corners in' the tube automatica-lly eitect a turbulence as shown. thereby resulting in a thorough mixing of the fluids before reaching the bu-rners.

Friction between the fluids and the sidewalls ot the tubeeffect aprog're'ssively slower velocity ofmixture flow as the combustible mixture travels along the tube. In order that; the volume of fluid flow be uniform to all of the burners, the mixing tube is tapered at its forward end as previously described. This progressive reduction in cross-sectional. area of the tubei'nsures a more nearly uniform volume of gas and air mixture to each burner without regard to the positionthereof along the' length of the tube by'increasing. the; velocity toward the end of the tube.

A separate or secondary supply of air is provided to materially increase the speed of combustion at the burners andthe pilot generator. It'ha-s been. foundthat for more complete combustion additional oxygen is desirable over that in the primary air. This added oxygen is supplied by the flow of air through the housing.

At the openend of the housing is. alight-angular. shaped cover 60 havihgchannel legs 61. and 620i unequallength. The channels fri'ctionall y embrace the sides of the housing in overlapping relation. The longer leg 61, being shorter than the height'of thehousing,. etfects an opening 63 across the bottom of'the housing thereby defining a secondary air inlet. Should it be necessary to increase the size of this opening, two methods are available. The cover 60 is capable of being reversed with the shorter leg 62 applied over the end of the housing and the longer leg 61 on the top thereof. In this position, shown in dotted lines in Figure 1, the size of the opening 63 is increased by the difference in length of legs of the cover. The inlet area may also be varied in size by bending the flaps 64 and 65 down from the bottom wall of the housing at its open end, as shown in Figure 5. By bending the flaps downwardly (Figure 3) the secondary air inlet area is adjusted as desired.

Secondary air flows through the enclosed portion of the housing or wind-box 11 to the open section in which is located the radiant burners. As the air rises between the burners it is introduced to the small flames at the sides thereof. Oxygen in suflicient quantity is thereby provided for complete oxidation. The direction of movement of the air is such that the products of combustion are almost immediately removed from the flame zone and the longer burning flames are directed against the radiant burner surfaces and away from the walls of the housing thereby increasing the efficiency of the burner. Direction of the flames is accomplished by providing air spaces between the burners and between each burner and adjacent walls of the housing including the firewall. Furthermore, the tops of the radiant burners are positioned below the top of the housing to insure the introduction of all secondary air from below thereby directing the air flow through the flame region and not above it to eliminate incomplete combustion.

As in the case of the mixing tube, a sloping wall may, if desired, be provided in the housing to effect a uniform volume of air to all of the burners. A progressive reduction in cross-sectional area between the sloping wall 21 and the bottom of the burners insures an even flow in the volume of secondary air between all of the burners by increasing the velocity toward the end of the housing.

It will be noted that the opening 43 in the firewall is larger than the pilot generator. As a result, secondary air is supplied to the generator both through the opening and along the forward face of the firewall. By such a construction, all of the secondary air for the generator may be supplied through the over-size opening in the firewall thereby effecting an air supply channel separate from the air supply channel for the burners.

As the combustible gas and air mixture emerges from the fuel openings 28 in the burners, it is ignited initially by the pilot flame in the space between the firewall and the next adjacent radiant burner. As the flames of combustion travel upwardly,'the columns of fuel mixture rising in the spaces between adjacent radiant burners successively ignite efiecting complete ignition throughout the burner area. This ignition continues so long as the pilot generator is lighted and the room thermostat requirements are not satisfied. Provided the pilot generator remains lighted, the operation of the burner is automatic. Should the pilot generator become extinguished, it is again lighted by the pilot lighter in the manner previously described.

While I have described the movement and effect of the secondary air, it will be seen that the gas burner described herein possesses all of the same advantages when all of the air necessary for the burning of the gas is introduced as primary air. Furthermore, although the radiant bumers are shown and described in a vertical position, the radiating surfaces may be horizontal or at any angle to the vertical provided there is satisfactory flow of gas and air to the flames for complete combustion.

Arrangement of the spaced burners within the burner area in a manner other than shown and described herein,

is possible. In any such modified arrangement, however, it is desirable to insure the positive ignition of fuel by locating the pilot flame in one of the columns of rising fuel and air adjacent the burners.

While I have thus described and illustrated a specific embodiment of my invention I am aware that numerous alterations and changes may be made therein without departing from the spirit of the invention or the scope of the appended claim in which:

I claim:

'A heating device comprising a unitary elongated housing having a bottom wall having opposing side and end edges, side walls connected to and upstanding from the side edges of the bottom wall, end walls connected to and upstanding from the end edges of the bottom wall and connected to the side walls, said side and end walls being coextensive in height, a top wall extending from the upper end edge of one end wall to a point spaced from the other end wall and connected to the upper end edges of the side walls to provide covered and uncovered portions in the housing, a firewall depending from the inner end of the top wall and extending completely across the housing between the side walls and spaced above the bottom wall, a mixing tube connected to a source of fuel and extending longitudinally in the housing from one end wall to the other end wall and mounted on the bottom wall thereof, said firewall having its lower end resting on the top of the mixing tube, narrow burners positioned transversely of the housing in the uncovered portion and extending between the side walls, said burners being vertically arranged and positioned in longitudinally spaced relation between the firewall and the other end wall of the housing, said burners having lower ends secured to the top wall of the mixing tube, said top wall having openings communicating with the burners, said lower ends of the burners being disposed substantially coplanar with the lower end of the firewall and having upper ends lying slightly below the plane of the top wall, said burners having spaced apart confronting sides which define vertical air passageways, said sides having fuel jet openings therein with the jet openings on one side of a burner facing the jet openings in the confronting side of an adjacent burner and the air passageway therebetween, air inlet means in the uncovered portion of the housing to admit air into the uncovered portion for passage below and up between the burners and means for regulating the flow of air through the air inlet means.

References Cited in the file of this patent UNITED STATES PATENTS 131,994 Bradford Oct. 8, 1872 619,623 Schlumberger Feb. 14, 1899 1,060,906 Kiefer May 6, 1913 1,838,656 Bullock Dec. 29, 1931 1,991,609 Furlong Feb. 19, 1935 2,059,360 Keith Nov. 3, 1936 2,131,221 Crary Sept. 27, 1938 2,168,758 Ballamy Aug. 8, 1939 2,215,983 Smith Sept. 24, 1940 2,231,391 Martois Feb. 11, 1941 2,263,170 Haedike Nov. 18, 1941 2,357,647 Greene Sept. 5, 1944 2,367,143 Schrader Jan. 9, 1945 2,480,046 Reeves Aug. 23, 1949 2,541,315 West Feb. 13, 1951 2,559,979 Martois July 10, 1951 2,560,184 Norman July 10, 1951 2,560,888 Reed July 17, 1951 2,625,992 Beck Jan. 20, 1953

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