US3260300A - Fluid fuel burner assembly - Google Patents

Description

5 Sheets-Sheet 2 J. W. LANNERT ET AL FLUID FUEL BURNER ASSEMBLY July 12, 1966 Filed April 29, 1960 whim t 0": I l ldul a x M c ..a F \4 1| J. W. LANNERT ET AL FLUID FUEL BURNER ASSEMBLY July 12, 1966 Filed April 29, 1960 5 Sheets-Sheet 5 Wr/klb July 12, 1966 1 w, LANNERT ET AL 4 3,260,300

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I I 2 i f w J55 14-0 .13 171 5 I ,Jjo '5 J14- j'jz 12 \W 149 fljforneys L July 12, 1966 Filed April 29, 1960 J. W. LANNERT ET AL FLUIDVFUEL BURNER ASSEMBLY 5 Sheets-Sheet 5 Ema: (Ill 177 flbward EBre/i "7J5 w gzm United States Patent 3,260,300 FLUID FUEL BURNER ASSEMBLY James W. Lannert and Howard E. Brehm, J12, St. Joseph,

Mich., assignors to Whirlpool Corporation, a corporation of Delaware Filed Apr. 29, 1960, Ser. No. 25,793 3 Claims. (Cl. 158116) This invention relates to a flui-d fuel burner assembly of the type used, for example, in a gas stove.

One of the features of this invention is to provide an improved fluid fuel burner assembly preferably of small horizontal cross sectional dimensions in which the flame is projected radially with respect to the central axis of the assembly to extend around the assembly with the flame being substantially in sheet form and preferably having a layer of secondary air above the flame which would place it between the main body of the flame and the article such as a pot or pan being heated.

1 A further feature of the invention is to provide an improved assembly in which there is a high turndown ratio such as a maximum of approximately 36: 1.

Another feature of the invention is to provide an improved fluid fuel burner assembly having means for providing a fuel-primary air mixture for ignition to provide a sheet of flame and means for providing an overlying body of secondary air in which the secondary air may be supplied by a blower and wherein the secondary air at its exit from the assembly will be at a relatively high velocity.

Another feature of the invention is to provide an improved fluid fuel burner assembly in which an internal passage is provided to supply a fuel-air mixture for initial ignition with this passage being vented through one or more side openings to the exterior of the assembly for ignition by a suitable device such as a pilot flame so that the flame of this initially ignited mixture is carried upwardly to the emerging main fuel-air mixture from the burner for ignition thereof, the upper end of the initial ignition fuel-air mixture passage preferably being vented to atmosphere in order to prevent excessive pressure buildup within this passage when the gas and primary air pressure is increased within the burner.

Yet another feature of the invention is to provide a fluid fuel burner assembly in which improved means are provided for sealing the assembly to a top plate such as a range top plate whereby cleanability is vastly improved.

A further feature of the invention is to provide an improved burner assembly located adjacent means providing a pilot flame together with a shield surrounding the upper portion of the assembly and enclosing the pilot flame.

A further feature is to provide a powered secondary air burner having parts common to an atmospheric burner in which the secondary air for combustion is not powered.

Other features and advantages of the invention will be apparent from the following description of certain embodiments thereof taken in conjunction with the accompanying drawings. Of the drawings:

FIGURE 1 is a sectional elevational view partially broken away showing one embodiment of a fluid fuel burner assembly arranged in conjunction with a range top and associated structure.

FIGURE 2 is a plan view of the burner assembly of FIGURE 1.

FIGURE 3 is a vertical sectional view taken substantially along line 33 of FIGURE 1.

FIGURE 4 is a horizontal sectional view taken substantially along line 44 of FIGURE 3.

FIGURE 5 is a fragmentary sectional view showing a second embodiment of the invention.

FIGURE 6 is a fragmentary vertical sectional view similar to FIGURE 3 but showing a third embodiment of the invention.

FIGURE 7 is a view similar to FIGURE 1 but showing a fourth embodiment of the invention.

FIGURE 8 is a view similar to FIGURE 1 but showing a fifth embodiment of the invention.

FIGURE 9 is a view similar to FIGURE 3 showing a sixth embodiment of the invention.

FIGURE 10 is a sectional view taken substantially along line 1010 of FIGURE 9.

FIGURE 11 is a sectional view taken substantially along line 1111 of FIGURE 10.

FIGURE 12 is a fragmentary sectional view taken sub stantially along line 12-12 of FIGURE 10.

FIGURE 13 is a view similar to FIGURE 9 but showing a seventh embodiment of the invention.

The fluid fuel burner assembly of this invention is particularly useful in gas ranges and the like particularly at the top of the range. In the embodiment illustrated in FIGURES l-4 inclusive the range includes a sheet metal range top 10 having a surface portion 11 of counter height with the main body portion 12 thereof lowered. Located in this range top are a plurality of burner assemblies 13 spaced in the customary manner of which only one is shown for illustrative purposes. The burner assembly 13 extends through an opening in the range top 10 formed by an upturned annular flange 14 with the burner assembly being sealed to this flange and the adjacent portion of the top '10 by means of a resilient heat-resistant rubbery seal The fluid fuel burner assembly 13 comprises a burner head or head unit 16 of generally cylindrical shape including a cylindrical outer wall 17, a generally vertical wall 18 spaced inwardly thereof and a central tube 19. The wall.=18 is of a heavier construction than the outer wall 17 as it serves as a principal support of the burner head unit.

The top of the wall 18 projects outwardly and upwardly as indicated at 20 to overhang partially an upwardly and outwardly extending annular flange 21 on the outer wall 17. The space between the wall flange 20 and the wall flange 21 provides an outlet 22 extending somewhat less than 360 around the burner body.

The top portion of .the burner head unit 16 is provided with a plurality of exit ports 23. These ports may be formed by drilling the top of the cylindrical wall 18 with the drilled ports having open tops as indicated in FIG- URE 4 and are closed by an overlying plate 24.

The plate 24 is relatively heavy and is of generally short funnel shape with a central portion 25 and an upwardly and outwardly extending overlying portion 26. The outer edge of this overlying portion 26 closes the upper extremities of the drilled ports 23.

The left-hand side of the wall 18, as viewed in FIG- URE l, is recessed inwardly and includes an upper portion 27 and an inwardly sloped lower portion 28. The space between the portions 27-28 and the adjacent outer wall portion 29 provides an initial ignition fuel-air mixture passage 30. The outer extremity of the upper end of this passage 30 is defined by a wall portion 29a which is aligned with portion 29 and which is integral with wall 18. The outer wall portions 29 and 29a are provided with openings 31 and 31a extending vertically from adjacent the bottom of the burner head unit 16 to the plurality of drilled ports 23.

Attached to the lower end of the central portion 25 of the plate 24 is a depending tube 19 having its upper end attached to this portion 25. Extending across the central portion 25 of the plate 24 is a spider 33 providing a plurality of circumferentially arranged openings. Mounted on this spider by means of a post 34 is a top plate 35 having its outer edge substantially vertically aligned with the outer edges of th flange 20 and the plate 24. The top plate 35 is spaced from the plate 24 to provide an exit J opening 36 extending completely around the top of the burner assembly. In this embodiment wall 17, Wall 18, plate 24, spider 33, post 34 and top plate 35 are all attached together to form the burner head or head unit. Tube 19 may also be attached to this unit, if desired, as may be hood 63, the function of which will be described later.

The burner unit 16 is positioned, when assembled, on a burner base 37 having a top wall 33 with its inner edge spaced from tube 19 to provide an opening 39 therearound and a cylindrical side wall 40. The upper Wall 38 of burner base 37 is provided with a plurality of openings 42 whose function is to provide communication between passages 47 and 45. The plurality of openings are positioned on a circle with th longitudinal axis 43 passing through the center of this circle. Also provided in the upper wall 38 of burner base 37 is a single opening 41 that with adjacent holes 42 allows the primary fuel-air mixture to pass from passage 47 into the initial ignition passage 3%. The center of the tube 19 provides a passage 46 and the space between the tub 19 and the Wall within the base 37 provides the passage 47.

Connected to the bottom of the base 37 to communicate with the passage 47 is a conduit pipe 48 for gas and primary air mixture.

The burner end of this pipe 48 is assembled in a sealed relationship to burner assembly 13. This is provided by having the inner end turned outwardly to provide an annular flange 49 which is held in a groove 50 and which is sealed to the base 37 as by a resilient seal member 51.

A pipe 52 for air under superatmospheric pressure is provided on the bottom of the base 37 communicating with the chamber 53 that is provided with a bottom wall 54 with this chamber opening upwardly into the passage 46 in the interior of the tube 19. The inner end of the pipe 52 is provided with an orifice 55 through which the air flows from the pipe 52 into the chamber 53.

Extending around the wall 40 beneath the adjacent portion 12 of the range top 10 is a transverse supporting metal plate 56, The bottom of the resilient seal member 15 rests against the top of this plate 56. Extending through this plate 56, an outwardly extending potrion 57 of the seal member 15 and the range top 10 is a threaded pilot nozzle 58 held in place by upper and lower clamping nuts 59. The bottom of this nozzle 58 has attached thereto a fuel pipe 66 to provide gaseous fuel to the interior of the nozzle 58. This fuel is emitted through an opening 61 in the top of the nozzle 58 to provide a pilot flame 62 extending toward the vertical row of openings 31 in Wall 29 which serves to ignite the fuel-air mixture as it passes through the openings 31 from the initial ignition fuel-air passage 30. If desired, a single elongated opening or a plurality of elongated openings may be provided instead of the plurality of circular openings 31 shown.

Attached to the outer wall 17 is a depending hood 63 having its bottom spaced from the range top flange 14. One side of this hood 63 extends outwardly to enclose the top end of the pilot nozzle 58 and is provided with a sloping top 64 in which is located a relatively large opening 65 adjacent the outer wall portion 23 containing the openings 31. As can be seen in FIGURE 1, the bottom of this hood 63 is spaced from the range top 119.

In operation, gas and primary air under pressure flow through the pipe 48 and into the passage 47. The mixture then flows up through the opening 39 into the passage 44 and out the burning ports 23. This gas and primary air mixture also flows through opening 41 into the initial ignition passage 34 and through the openings 42 into the passage 45 and out the gas relight outlet 22. In addition, secondary air under pressure is fed through the pipe 52, orifice 55 and chamber 53 into the passage 46 and through the openings in the spider 33 to flow outwardly under pressure through the exit opening 36.

From the ignition openings 31 and 31a the primary air and gas mixture flows to the exterior surface of the wall 4 portions 29 and 29a and is ignited by the pilot flame 62 to carry the flame upwardly to the main ports 23 to ignite the primary air and gas mixture flowing therefrom,

As can be seen, the flame emerging from the main burner ports 23 is projected outwardly at a slight upward angle all the way around the burner assembly. The top of this sheet of flame is contacted by an outwardly projecting layer of secondary air flowing under pressure from the exit opening 36. Thus the sheetof secondary air is between the sheet of flame and the pot or vessel being heated. It is this sheet of secondary air which produces more uniform heat distribution, especially at low heat inputs, to thereby minimize hot spots in pans or utensils sometimes produced by conventional burners. A pot or vessel may be supported on a customary grate as illustrated at 66.

In this invention a blower may be used to provide the secondary air. The burner of this invention permits an extremely high turndown ratio of its maximum to minimum inputs. Thus in some embodiments this turndown ratio has been as much as 36:1 although satisfactory commercial ratios have been found to be from about 12:1 to 24:1. The burner of this invention provides extremely efiicient performance with a relatively small cross sectional area burner. Thus by providing the pressurized secondary air as described, there is no need for the usual aeration bowl and large open grate customarily used in burners for stoves. In addition, superior cleanability is achieved and the burning unit is considerably more attractive than the usual unit.

The design of the burner of this invention is such that the high turndown ratio is achieved both by providing for an increased maximum input for fast heating operations without the danger of the flame being pulled from the burner ports, and providing for a decreased minimum input for simmering operations without localized hot spots.

The ports of a gas burner must be small enough so that the linear velocity of the primary air-fuel mixture passing through the ports at the lowest burner input is greater than the linear combustion rate of the mixture. This assures that flash back, which is the process of the combustion moving toward the air-fuel mixture source, will not occur. However, as the input to the burner is increased, the linear velocity of the air-fuel mixture passing through the burner increases to the extent that this linear velocity is considerably greater than the linear combustion rate of the mixture and the flame is actually blown off of the burner.

On burners of this type, this condition makes it necessary to limit the upper input to the burner. The openings 42, passage 45, and outlet 22 combine to overcome this high input limitation on the burner of this invention. The area of each opening 42 is made small enough so that when the burner is operated through its low input range only a negligible amount of the fuel-air mixture passes through each opening 42 and thus a visible ring of flame will not be present at the continuous outlet 22. However, as the input to the burner is increased into the higher input range the pressure in passage 47 increases correspondingly and enough air-fuel mixture passes through the openings 42 into the passage 45 and is ignited at 22 to form a visible continuous ring of flame directly beneath the main burner ports 23. As the input is increased, the linear velocity of the air-fuel mixture passing through the ports may become great enough so that the flame is blown oil? of the burner. When this happens, the flame retention or flame relight ring which is burning at continuous outlet 22 will continuously re-ignite the air-fuel mixture passing through the burner ports 23. This flame retention or flame relight ring therefore permits the increasing of the input to the burner for fast heating operations.

It is presently common practice on more expensive burners for low inputs to place a small simmer or low heat burner Within the normal burner. Even though this type of low heat burner has a small input, the area of the flame emitted is also very small and a hot spot will develop on the utensil directly above this small flame. This hot spot is of such intensity that if the contents of the utensil, such as white sauce, are not continually stirred, they will burn. However, the burner of this invention, with inputs comparable to the lowest inputs of the simmer or low heat burner, by means of the powered blanket of secondary air passing through continuous outlet 36 flattens the flame and spreads the heat of the flame at this low input into a large area such that no hot spots develop so that, for example, a white sauce in a utensil will not burn when left unattended over this type of burner. The effect of the blanket of powered secondary air at the minimum input of approximately 500 B.t.u. per hour is so pronounced in its elimination of hot spots that a piece of paper can be placed of an inch above the flame coming from ports 23 without igniting. Of course this blanket of powered secondary air even at the maximum burner input acts to spread the flame over the entire area of the bottom of the utensil.

Although the dual type gas range top burners that use the center simmer burner for low inputs are capable of operating in the 500 B.t.u. per hour input range, the much more common single range top burner is usually limited to a minimum input of approximately 1000 B.t.u. per hour which is too high for some simmering operations.

When the burner is operated at a higher rate by increasing flow of gas and primary air there is no danger of the pilot flame that is located on the exterior surfaces of the wall portions 29 and 29a adjacent the openings 31 and 31a being blown off. This is prevented because the top of the pilot passage is vented through two of the main ports 23 by way of passage 30a (FIGURE 4) in the illustrated embodiment, thereby preventing an excessive pressure build-up within the pilot passage. In addition, even at this high pressure when the burner is operating at high capacity, flow through the pilot passage 30 is restricted by reason of the relatively small flow passage openings 41 and 42.

If desired for economy reasons convection secondary air could be used. In this instance it would be necessary to remove the bottom wall 54 of the chamber 53, spider 33, post 34 and top plate 35 to permit secondary air to flow by natural convection into the passage 46 and out the top of tube 19 where it is forced outwardly in all directions as it contacts the bottom of the utensil.

In the embodiment of FIGURES 1-4, the flanges 20, 21 and 26 are sloped upwardly and outwardly. In the embodiment of FIGURE 5 the flange 67 which corresponds to the flange 20 extends substantially horizontally but has a downwardly and outwardly sloped bottom 68 while the flange 69 which corresponds with the flange 21 is sloped outwardly and downwardly. With this construction the flame emerging from the outlet 70 is directed generally downwardly at the outer edge of this outlet. Under certain conditions, this downwardly directed configuration is more desirable for ignition purposes because of the localized gas turbulence produced by this construction.

In the embodiment shown in FIGURE 6 there is illustrated a manner in which a sensor control unit 71 may be positioned in the burner. As is well known, sensor controls are used for thermostatic control of burner flame depending upon the temperature of the vessel or pot being heated. In this embodiment the sensor body 72 extends upwardly through the bottom wall 54 into the passage 46 with the sensor body being spaced inwardly of the tube 19 to provide fluid flow therebetween. The bottom of the sensor is held in place by means of a plate 73 held in position by bolts 74. Sealing gaskets 75 and 76 are employed in order to seal the spaces around the bottom of sensor control 71. The usual control wires 77 are provided leading to operate the customary solenoid valve (not shown) in the gas supply line; The top of the sensor unit 71 includes the usual spring loaded 6 sensor 78 which will be depressed against the urging of the spring 79 to the position shown in dotted lines when the sensor is in use.

In the embodiment shown in FIGURE 7 there is provided the primary air and gas supply passage 80, the pipe 81 leading to this passage, a secondary air passage 82 and a pipe 83 leading thereto, the secondary air outlet 84, main burner ports 85 and flame relight ring outlet opening 86. In this embodiment the pilot nozzle 87 and pilot flame 104 are located beneath the range top 10 and the initial ignition passage 88 extends downwardly beneath this range top. A shield 89 is provided above the pilot nozzle 87 in order to shield the pilot flame and prevent overheating of the range top 10 above the pilot. The range top around the burner 90 of this embodiment is provided with an upwardly extending flange 91 spaced outwardly thereof to provide an air passage 92. The top of this passage is enclosed by an outwardly spaced hood or shield 93 with dependent sides 105 around which is spaced the lower supporting portion of grate 94. The opening 92 covered by the hood or shield 93 except for a small pilot outlet opening 95 permits an additional supply of secondary air to flow from under the range top 10, through the annular opening 92 downwardly and outwardly beneath the hood or shield 93 and upwardly around this hood or shield 93 to the flame area. In this embodiment the placing of the pilot beneath the range top removes it from sight and results in a controlled range top. The operation of this embodiment is otherwise essentially the same as that shown in the first embodiment.

The embodiment of FIGURE 8 is essentially similar to the embodiment of FIGURE 1 except that here the pilot flame 106 emanates from opening 107 at the top of an internal fuel passage 96. In this embodiment the passage 96 is formed within the burner base 97 so that this base, which may be a casting or the like, may be fitted closely to the drip pan 108 adjacent the pilot passage 96 in contradistinction to the embodiment of FIG. 7. Otherwise, the operation is essentially the same as that previously described with secondary air being provided through the central passage 98 to flow out the opening 99, primary air and gas mixture being provided from a passage 100 to flow out the main burner opening 101 and the flame relight ring burning being provided by flow of primary air-gas mixture from the passage 100 through openings (not shown) in a top wall 102 of burner base 97 to flow out the exit opening 103.

In the embodiment of FIGURES 9-12 the burner assembly 109 comprises an integral burner base 110 of generally annular shape that extends above and below the range top 10 and metal plate 56. The portion of the base 110 beneath the plate 56 is provided with a radially extending tubular projection 111 provided on its inner surface with a pair of annular inwardly extending projections 112. Extending into this tubular projection 111 is a pipe 113 for supplying gas and primary air in the manner previously described in connection with the other embodiments. Located between the inner edges of the annular projections 112 and the outer surface of the pipe 113 is a compressed resilient sealing member 114 such as a rubber seal so as to provide a fluid seal.

The bottom of the burner base 110 is closed by a .closure 115. The top of this closure 115 is sealed to the bottom of the base 110 by a gasket 118. The closure 115 is provided with an upwardly extending tubular part 116 located substantially concentrically of the burner base 110. Extending across the bottom of this tubular part 116 is the bottom closure 117. Formed integrally with the bottom closure 117 is a radially extending pipe section 119 that functions to supply air in the manner previously described. The tubular projection 111 and the annular projections 112 previously mentioned are formed by cooperating halves at the bottom of the burner base 110 and the bottom closure 115.

Positioned on the top of the burner base 110 is a preassembled unitary burner head 120. This burner head or heat unit comprises an outer cylindrical part 121 having an outwardly and upwardly extending flange 122 and a concentric inner cylindrical part 123 having at its upper end an outwardly and upwardly extending flange 124. The lower flange 122 is provided with upwardly extending spaced portions 125 which are attached by a staked connection as indicated at 126 to the bottom of the upper flange 124. The spacing between these portions 125 provides for upwardly and outwardly extending ports 127 functioning similarly to the exit ports 23 of the embodiment of FIGURES 1-4.

Located within the burner head 120 integrally with and spaced inwardly of the cylindrical part 123 is a spider 128 on which is mounted by means of a rivet 129 a deflector plate 130. This deflector plate operates in substantially the same manner as the previously described plate 35 of the embodiment of FIGURES 1-4.

Extending upwardly from the tubular part 116 is a central tube 131 having its lower end received in the tubular part 116 and its upper end received in the cylindrical part 123. This tube 131 provides a passage 132 for the secondary air from the pipe section 119.

The burner base 110 and the burner head 120 are held in assembled relationship by the bottom of the cylindrical part 121 resting on an inwardly extending shelf 133 that extends inwardly of and is integral with the cylindrical burner base 110. The cylindrical part 110 is spaced outwardly of the cylindrical part 121 of the burner head 120 to provide a passage 134. This passage 134 communicates through a plurality of holes 135 with the internal chamber 136 that receives air and gas mixture through hte pipe 113. The upper edge of the burner base 110 is sloped upwardly and outwardly and is spaced from the lower surface of the flange 122 in order to provide an exit port 137 that is similar to and functions substantially identically with the outlet 22 of the embodiment of FIGURES l-4.

The base of the bottom closure 115 of the burner assembly is provided with spaced feet 138 resting on the burner box bottom 139. If desired, this burner unit may be suspended from the plate 56 by means of suitable fasteners connected between plate 56 and burner base 111).

In this embodiment, as in the embodiment of FIG- URES 1-4, the burner assembly is sealed to the range top and to the plate 56 with a resilient seal member 140.

Formed integrally with the burner base 110 and extending outwardly therefrom is a block 141 provided with a passage 142 the top of which is provided with a pilot fitting 142a and the bottom of which is provided with a fitting 143' for a gas line 144. This combination provides the gas supply for the pilot flame 145. This integral pilot structure also permits easier assemblage of the burner assembly and facilitates closer control of critical dimensional tolerances between the pilot burner and the burner head 120. Adjacent the top of the pilot fitting 142a the upper portion of the burner base 110 is provided with an inner wall 146 and an outer wall 147 spaced from each other to provide a chamber 148. This chamber 148 forms an initial ignition passage in which the gas is ignited by the pilot flame 145 through an elongated vertical slit 149 in the wall 147. Air and gas are provided in the initial ignition passage 148 through an opening 150.

The burner assembly is provided with a depending hood or shield 151 having an outwardly projecting portion 152 to enclose the pilot flame 145. Within the hood 151 is a pilot burner shield 153, The hood 151 rests on an outwardly extending shelf 154 on the burner base 110 and can be removed from the burner assembly for cleaning purposes merely by lifting it upwardly from the 8 burner assembly without removal of any other burner parts.

The embodiment of FIGURES 9-12 is of course a power burner with the air and fuel being supplied under pressure as described in the first embodiment of the invention. In this instance, the grate will support a pan, pot or similar utensil at the level indicated by the line 155 of FIGURE 9. When it is desired to operate the burner as an atmospheric secondary air burner itis only necessary to remove the bottom closure 117 and the spider 128 and deflector plate 130. When this is done the resulting burner assembly will have the appearance of the embodiment of FIGURE 13. Here secondary air flows upwardly at atmospheric pressure through the passage 132. In this instance, the top of the grate will support the pan, pot or other utensil at the level indicated by the line 156 of FIGURE 9. This higher elevation permits additional air to be supplied at the .top of the burner. In this embodiment of FIGURE 13 a deflector disc 157 is attached to the top of the grate 158 in order to aid in deflecting this air outwardly. Suflicient air is provided for the secondary air passage of the embodiment of FIGURE 13 by reason of the feet or spacer lugs 138 permitting air to enter between the burner assembly and the burner box bottom 139.

In addition to the outstanding operating characteristics of the burner of this invention, it is important from the housewifes point of view to realize the important improvements in range top cleanability that this burner provides over present gas range top burners. In the common range top application of the burner of this invention it is likely that a plurality of burners such as illustrated herein would be used. These burners would all be mounted on the same main body portion 12 and when the grates 66 and the hoods 63 were removed it can be seen that the entire range to-p area would be completely exposed for a thorough cleaning. Since all members of the burners that protrude through the main body portion 12 are sealed, an ample amount of cleaning fluid can be used without this cleaning fluid getting into the inner parts of the range.

Having described our invention as related to the embodiments shown in the accompanying drawings, it is our intention that the invention be not limited by any of the details of description, unless otherwise specified, but rather be construed broadly within its spirit and scope as set out in the accompanying claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A fluid fuel burner assembly comprising: a burner head defining a main passage, an auxiliary passage and a secondary air passage, said burner head having a closed end, said passages each having an exit opening facing away from the longitudinal axis of the burner head and being located adjacent said end, the main passage exit opening being disposed between the auxiliary passage exit opening and said end, and the secondary air passage exit opening being disposed between said main passage exit opening and said end; structure defining a free space surrounding the burner head outwardly of said exit openings and upwardly open to atmosphere; means for supplying combustible fuel-air mixture to said main and auxiliary passages to provide a main flame at said main passage exit opening and an auxiliary flame at said auxiliary passage opening; means for supplying secondary air under gauge pressure to said secondary air passage; and flow control means for causing the rate of flow of fuel-air mixture from said auxiliary passage exit opening to be less than the rate of flow of fuel-air mixture fro-m said main passage exit opening thereby to prevent extinguishment of said auxiliary flame, the secondary air being directed by said secondary air passage exit opening to maintain the fuel-air mixture passing from said main passage exit opening in igniting association with the auxiliary flame.

2. A fluid fuel burner assembly comprising: a burner head defining a main passage, an auxiliary passage, and a secondary air passage, said burner head having a closed end, said passages each having an exit opening facing away from the longitudinal axis of the burner head and being located adjacent said end, the main passage exit opening being disposed between the auxiliary passage exit opening and said end, and the secondary air passage exit opening being disposed between said main passage exit opening and said end; means for supplying combustible fuel-air mixture to said main and auxiliary passages to provide a main flame at said main passage exit opening and an auxiliary flame at said auxiliary passage opening; means for supplying secondary air under gauge pressure to said secondary air passage; flow control means for causing the rate of flow of fuel-air mixture from said auxiliary passage exit opening to be less than the rate of flow of fuel-air mixture from said main passage exit opening thereby to prevent extinguishement of said auxiliary flame, the secondary air being directed by said secondary air passage exit opening to maintain the fuel-air mixture passing from said main passage exit opening in igniting association with the auxiliary flame, said burner head further having a pilot passage for fuel-air mixture provided with an exit opening communicating with the exterior of the burner head adjacent the main passage and auxiliary passage exit openings; and means for providing a pilot flame adjacent said pilot passage exit opening.

3. A fluid fuel burner assembly comprising: a burner head defining a main passage, an auxiliary passage, and a secondary air passage, said burner head having a closed end, said passages each having an exit opening facing away from the longitudinal axis of the burner head and being located adjacent said end, the main passage exit opening being disposed between the auxiliary passage exit opening and said end, and the secondary air passage exit opening being disposed between said main passage exit opening and said end; means for supplying combustible fuel-air mixture to said main and auxiliary passages to provide a main flame at said main passage exit opening and an auxiliary flame at said auxiliary passage opening; means for supplying secondary air under gauge pressure to said secondary air passage; and flow control means for causing the rate of flow of fuel-alr mixture from said auxiliary passage exit opening to be less than the rate of flow of fuel-air mixture from said main passage exit opening thereby to prevent extinguishment of said auxiliary flame, the secondary air being directed by said secondary air passage exit opening to maintain the fuel-air mixture passing from said main passage exit opening in igniting association with the auxiliary flame, said burner assembly further including structure defining a free space surrounding the burner head outwardly of said exit openings and upwardly open to atmosphere and extending to below the level of said auxiliary passage exit opening to provide atmospheric air from below upwardly to the auxiliary flame.

References Cited by the Examiner UNITED STATES PATENTS 2,111,369 3/1938 Marvin et al 12639 X 2,220,572 11/ 1940 Knupp 15899 2,298,307 10/ 1942 Parker 126--39 2,467,626 4/1949 Norman 158-116 X 2,590,948 4/1952 Perow 158-116 2,661,057 12/1953 Resek 158-1 10 X 2,664,153 12/1953 Swenson et al 1581 15 X 2,759,533 8/1956 Getz et a1 l58110 2,843,199 7/1958 Brodbeck et a1 1581 16 2,870,829 1/ 1959 Williams. 2,960,157 11/1960 Dolby 158-116 3,002,513 10/ 1961 Morasch 126299 FOREIGN PATENTS 78,156 11/1894 Germany. 309,329 11/ 1955 Switzerland.

OTHER REFERENCES German printed application 1,032,196, printed June 19, 1958 (2 pgs. spec, 1sht.dwg.).

FREDERICK L. MATTESON, JR., Primary Examiner.

PERCY L. "PATRICK, EDWARD J. MICHAEL,

Examiners.

H. B. RAMEY, D. C. BRUENING, Assistant Examiners.

Claims (1)

1. 3. A FLUID FUEL BURNER ASSEMBLY COMPRISING: A BURNER HEAD DEFINING A MAIN PASSAGE, AN AUXILIARY PASSAGE, AND A SECONDARY AIR PASSAGE, SAID BURNER HEAD HAVING A CLOSED END, SAID PASSAGES EACH HAVING AN EXIT OPENING FACING AWAY FROM THE LONGITUDINAL AXIS OF THE BURNER HEAD AND BEING LOCATED ADJACENT SAID END, THE MAIN PASSAGE EXIT OPENING BEING DISPOSED BETWEEN THE AUXILIARY PASSAGE EXIT OPENING AND SAID END, AND THE SECONDARY AIR PASSAGE EXIT OPENING BEING DISPOSED BETWEEN SID MAIN PASSAGE EXIT OPENING AND SAID END; MEANS FOR SUPPLYING COMBUSTIBLE FUEL-AIR MIXTURE TO SAID MAIN AND AUXILIARY PASSAGES TO PROVIDE A MAIN FLAME AT SAID MAIN PASSAGE EXIT OPENING AND AN AUXILIARY FLAMER AT SAID AUXILIARY PASSAGE OPENING; MEANS FOR SUPPLYING SECONDARY AIR UNDER GAUGE PRESSURE TO SAID SECONDARY AIR PASSAGE; AND FLOW CONTROL MEANS FOR CAUSING THE RATE OF FLOW OF FUEL-AIR MIXTURE FROM SAID AUXILIARY PASSAGE EXIT OPENING TO BE LESS THAN THE RATE OF FLOW OF FUEL-AIR MIXTURE FROM SAID MAIN PASSAGE EXIT OPENING THEREBY TO PREVENT EXTINGUISHMENT OF SAID AUXILIARY FLAME, THE SECONDARY AIR BEING DIRECTED BY SAID SECONDARY AIR PASSAGE EXIT OPENING TO MAINTAIN THE FUEL-AIR MIXTURE PASSING FROM SAID MAIN PASSAGE EXIT OPENING IN IGNITING ASSOCIATION WITH THE AUXILIARY FLAME, SAID BURNER ASSEMBLY FURTHER INCLUDING STRUCTURE DEFINING A FREE SPACE SURROUNDING THE BURNER HEAD OUTWARDLY OF SAID EXIT OPENINGS AND UPWARDLY OPEN TO ATMOSPHERE AND EXTENDING TO BELOW THE LEVEL OF SAID AUXILIARY PASSAGE EXIT OPENING TO PROVIDE ATMOSPHERIC AIR FROM BELOW UPWARDLY TO THE AUXILIARY FLAME.

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