US3219098A - Burner for gas range - Google Patents

Description

Nov. 23, 1965 V J. R. FULMER BURNER FOR GAS RANGE Filed Feb. 28, 1963 2 Sheets-Sheet 1 IN NTOR. Jon-m R. FULMER Nov. '23, 1965 F L 3,219,098

BURNER FOR GAS RANGE Filed Feb. 28, 1963 2 Sheets-Sheet 2 35 INVENTOR.

JOHN R. FULMER BY fia MAMLW /M 3,219,098 BURNER FOR GAS RANGE John R. Fulmer, Kankakee, Ill., assignor, by mesne assignments, to Geo. D. Roper Corporation, Kankakee, 11]., a corporation of Delaware Filed Feb. 28, 1963, Ser. No. 261,686 2 Claims. (Cl. 158-116) burner and adjacent the ports. However, difficulty is encountered when an attempt is made to use a Greek cross port configuration in a larger burner capable of a wide range of B.t.u. output. Inthe first place the flame at high levels is subject to the phenomenon known in the art as blowing, a condition where the flame tends to blow itself out by reason of the high velocity of the exiting air-gas mix. A flame at the threshold of this blowing condition is noisy, unstable, and subject to blowing out by drafts which may exist in the usual kitchen when a door is opened. Moreover, it is diflicult to adjust such burners for a wide range of B.t.u. out.- put since the setting of the. air shutter at the venturi is highly critical. As to the specific port contour, it is found that where ports of the Greek cross type are spaced closely together in order to achieve good ignition or carry-around the total port area is so large that the burner is incapable of reliable operation at extremely low B.t.u. per hour valve settings. 7

It is, accordingly, an object of the present invention to provide a gas burner construction which overcomes the disadvantages associated. with the use of ports of the Greek cross type. More specifically, it .is an object of the present invention to provide an improved burner for range top use which may be operated, by throttling adjustment of the control valve, over an. extremely wide range of heat output. It is therefore an object to provide a burner which is capable of an extremely high heat rate for. its size and .which produces a flame which is free of any blowing tendency, which is extremely. quiet even at the maximum setting, and which remains ignited even in the face of strong or sudden drafts. At the other extreme it is an object of .the present invention to provide a burner which maybe operated at low heat rates onthe order of 500 B.t.u. per hour or less for simmering or warming purposes and with a smallbutton flame being stably maintained at each of the burner ports. In this connection it is 'an object to provide a burner having good ignition characteristics with prompt carry-around of the-flame from one port to the next even at low valve settings and with prompt re-ignition in the event that the flame is extinguished at one or more of the ports due to a particularly severedraft condition. Thus it is an object to provideaburner which is safeand which insures against the escape of unignited gas."

It is an object related to the foregoing to provide a burner which is capable of operating stably over an extremely wide range of output, for example, 500 to United States Patent 3,219,098 Patented Nov. 23, 1965 ice 12,000 or more B.t.u. per hour but in which the air shutter is noncritical of adjustment.

It is still another object of the present invention to provide an improved burner for range use which maintains an even and symmetrical pattern of flame at high output and in which there is no possibility that the inrush of air-gas mix, and the resulting nonsymmetrical flow pattern, will distort the distribution of the air-gas mix to the ports in the various portions of the burner periphery. Thus it is an object to provide a burner capable of producing a symmetrical flame even though fed by a mixing tube which is connected and in an olfset position with respect to the burner axis.

It is, moreover, an object of the present invention to provide a burner which is easily and positively ignited from the burner pilot when the gas is turned on.

It is yet another object of the present invention to provide a burner which is easy and inexpensive to manufacture and which consists of a shell or burner body and a burner head insert telescoped together to complete the burner assembly and with simple means being provided for holding the two parts permanently in assembled relation.

In one of its aspects it is an object of the present invention to provide a burner having all of the above features and advantages but which is of hollow center construction, permitting the installation, centrally within the burner, of a temperature responsive head for the purpose of engagingthe underside of a cooking vessel for automatic adjustment of the supply valve thereby to maintain a predetermined temperature, a usage which takes full advantage of the capability of the burner to operate at the above-mentioned low turn-down rates.

Other objects and advantages of the invention will become apparent upon reading the attached description and upon reference to the drawings in which:

FIGURE 1 is a perspective view of a burner constructed in accordance with the present invention.

FIG. 2 is a vertical section of the burner of FIG. 1.

FIG. 3 is a fragmentary section of a portion of the burner head showing the profile of the adjacent burner ports.

FIG. 4 is a fragmentary section taken along the line 44 in FIG. 3 through a typical burner port and showingthe flame profile under conditions of maximum flow.

FIG. 5 is a view taken along the same section line as FIG. 4 but showing the appearance of the flame at minimumflow.

FIG. 6 is avertical section showing the pilot igniting means.

FIG. 7 is a top view of a burner constructed in accordance with the present invention at a reduced scale and partially diagrammatic showing the flame pattern and with the dotted outline indicating the tendency of the flame to become non-symmetrical, particularly at high input, in burners lacking the teachings of the present invention.

FIG. 8 is a section showing use of the present burner with a temperature sensing head to provide automatic control of flame level.

FIGS. 9 and 10 show modified'port contours which may be used in practicing the invention.

FIG. 11 is a fragmentary vertical section showing the oentral partition integrally formed in the burner body.

While the invention has been described in connection with certain preferred embodiments, it will be understood that the invention is not limited to the particular embodiments illustrated but includes the various alternative and equivalent constructions included within the spirit and scope of the appended claims.

Turning now to the drawings, there is shown a top-ofrange burner 20 including a mixing tube 21, a burner body 22, and a burner head 23. Gas is injected into the mixer tube 21 via a nozzle 24 under the control of a throttling valve 25, diagrammatically shown, which receives gas from a supply line or manifiold 26. Air is aspirated into the gas stream determined by the setting of an air shutter 27, with the air being admitted through ports 28. It will be understood that a number of burners, usually four, are employed in a typical range receiving gas from a common manifold and with each being under the control of a manual or automatic throttling valve.

In carrying out the present invention, and as shown more specifically in FIG. 2, the burner body 22 is of hollow, annular construction having a bottom 31, an upstanding sidewall 32 and a top surface 33 having an inturned skirt 34 defining a central, circular opening 35. For manufacturing convenience, the burner body is formed of two pieces of metal joined together at a horizontal seam 36. The burner tube is preferably integral with the burner body so that the seam 36 extends along the sides of the burner tube as illustrated. The burner head 23, previously mentioned, is preferably of hollow annular construction, telescoped within the burner body and closely fitted with respect to the opening 35 in the latter. In the preferred form of the invention the burner head includes a central, tubular portion 41 and a peripheral portion, or port ring 42. The tubular portion provides a straight vertical wall 43 and an outwardly extending flange 44. Interposed between the wall and the flange is an annular step or shoulder 45, the purpose of which will become clear as the discussion proceeds. The outer edge of the flange 44 is downwardly and inwardly turned over the upper edge of the port ring to provide a gas tight joint 46.

With regard to the contour of the port ring, it is of cylindrical shape formed with punched ports 51 and necked down to provide a shoulder 52 and depending skirt 53. The outer skirt is such as to fit snugly within the opening 35, with the shoulder 52 on the head firmly seated, as shown, on the ledge 33.

For the purpose of maintaining the two parts permanently assembled together and to produce a burner assembly of hollow construction, the advantages of which will be described shortly, the tubular wall portion 43 of the burner head is extended downwardly as indicated at 43a and a registering circular opening 31a is formed in the lower member 31. Spinning or flaring the edge 43 outwardly as shown provides a secure mechanical connection sealed against the escape of the air-gas mix. The body portion and head portion, nested together, form a compact, integrated and attractive unit.

For the purpose of lighting the burner, the burner body is provided with a pilot charge port coupled to a central pilot burner by a suitable flash tube. Thus, as shown in FIG. 6, a charge port 60 is provided in one side of the burner body and in alinement with a flash tube 61 communicating with a pilot burner 62. It will be apparent that when air-gas mix is fed into the burner body, the gas ejected through the charge port 60 is ignited thereby igniting a pilot flame on the charge port which ignites the air-gas mix emanating from the adjacent ones of the main burner ports 51.

In accordance with the present invention the main burner ports 51 are horizontally elongated and arranged in alinement, end to end, with the ports having suflicient area concentrated at the center of each of them so as to permit a high rate of flow and with the ends of the ports spaced sufliciently close together as to provide prompt carry-around of the flame upon ignition by the pilot on one side of the burner. More specifically, in accordance with the invention, a partition is provided within the burner structure for separating the burner space into a body, chamber and a head chamber and defining an annular restricted passage between them, symmetrically located with respect to the burner ports for providing throttling action at high rates of flow for stabilization of the flame and for equalizing the distribution of air-gas mix to the ports. In the present instance the partition is formed integrally with the port ring 42 by inturning the skirt 53 to form an inwardly projecting flange 70. The inner diameter of the flange is such as to provide an annular, somewhat restricted passageway 71 which is preferably of constant radial width. The flange 70 may be easily and accurately formed on the port ring by punching out the center of a cup-shaped blank.

Still further in accordance with the present invention, each of the elongated ports has, spaced in alined position below it, an auxiliary port of small cross sectional area in which throttling occurs under conditions of high gas fiow to improve the stability of, and to maintain, the flame at the associated main port. Prior to discussing the manner in which the partitioned burner body and novel arrangement of horizontally arranged ports cooperate to produce optimum flame conditions over a wide range of output, more detailed attention may be given to the preferred port configuration. Thus, turning to the port profile illustrated in FIG. 3, each of the ports 51 includes a pair of horizontally extending arms 51a, 51b. In order to produce a concentration of area at the middle of the port, the port includes short vertical arms 51c, 51d respectively. In a practical case each port may have a length on the order of 0.218, a height of 0.125, and the arms may be approximately 0.037 in width. As stated, it is desired for the ports to be spaced close together to facilitate carry-around, and spacing of A or less is preferred. Each of the auxiliary ports, indicated at 75, may have a diameter on the order of 0.052. Preferably the spacing between each main port and its auxiliary port should be sufficiently great so as to allow access of a certain amount of secondary air between the two ports and so that the ports act to produce separate, but merging, flames. Thus, a vertical port-to-port spacing of 0.068" is preferred.

While the preferred main port profile includes short vertical arms, it is to be emphasized that the invention does not, in its broader aspects, reside in the use of a cruciform. Other horizontally elongated port configurations which may be employed are shown in FIGS. 9 and 10 respectively. In FIG. 9 it will be noted that the port is of flattened T-shape having horizontal arms 51e, 51 and a short vertical arm 51g. If desired, the upper surfaces of the arms 51e, 51 may be angled as indicated at 51h, 51i so that the port assumes the shape of a blunt arrowhead. In each instance the horizontal elongation and close port-to-port spacing is maintained and the port area is concentrated at the center, immediately above and alined with the auxiliary port 75.

Experience shows that the above burner is easily lighted and produces a stable flame over a wide range of B.t.u. output while overcoming the disadvantages normally associated with the use of ports of the Greek cross type. Thus under conditions of high flow corresponding to the rate of 12,000 B.t.u. per hour, or higher, the control valve 25 is fully open so that a stream of air-gas rnix fed to the burner body at high velocity. This produces a large flame at each of the ports as indicated at in FIG. 4. In a burner of prior construction this high output condition tends to result in a noisy and unstable flame, with the flame tending to blow itself out by reason of the high velocity of the gas emitted at each of the ports. Because of the use of the elongated, horizontal port which characterizes the present construction, the air-gas mix which flows from the ends of the horizontal arms 51a, 51b, being throttled to a greater extent than the mix which is discharged at the center of the port, substantially reduces the blowing tendency at the ends, thus tending to keep the flame anchored to the port. Moreover, the air-gas mix which flows from each of the auxiliary ports 75, being throttled because of the small area, produces a closely held flame 81 (FIG. 4) which merges with the flame 80 and which tends to prevent the flame from blowing away along its bottom surface.

The partition 70 within the burners is found to contribute to the result achieved under conditions of high burner output. Thus under high flow conditions, the airgas mix entering at a substantial velocity at one side of the burner only may tend to produce a non-symmetrical current and pressure condition within the burner head, causing some of the flames to be larger than others. This is especially true where the burner has a profile such as shown in FIG. 7 with some of the flames tending to occupy an angled condition indicated 'by the dotted lines. As a result an incipient blowing condition may be set up in some of the flames, i.e., where the pressure is greater, short of full burner output which serves as a limitation upon the heat rate of the burner. In the present burner, by contrast, the currents and turbulences which exist in the lower chamber of the burner are largely isolated from the burner head. And, since the restricted orifice 71 is symmetrically arranged with respect to the burner ports, each of the ports is symmetrically supplied with air-gas mix. Moreover, it is found that the throttling effect which occurs in the restricted passageway 71 is effective primarily when the burner is turned full on, with the pressure drop between the two chambers under such conditions being just suflicient, when used in connection with the particular elongated ports, to insure that operation occurs at a point safely removed from the blowing condition. Equally important, it has been observed that use of the above construction makes the adjustment of the air shutter 27 substantially less critical than in prior designs of burners, thereby eliminating the need for precise service adjustment either when the range is installed or as a result of changes in gas pressure or other operating conditions as the range is used.

At the other extreme, it is found that the present burner permits turn-down to a low, stable simmering flame by adjustment of the control valve 25. Under such conditions, corresponding to an output of 500 B.t.u. per hour or less, each of the main ports evidences a small button of flame as indicated at 85 in FIG. 5. Flames having an individual button appearance are difficult to maintain in convential types of burners, being subject to blowing out by drafts and failure to reignite when only a portion of the flame circle has been blown out. It is found, however, that the present burner is capable of maintaining such a flame stably for long periods of time in spite of drafts and, in the event a portion of the circle is blown out, reignition promptly takes place. The present burner construction makes it unnecessary to use a separate simmer burner while nevertheless permitting high output when the cooking conditions demand it.

As a result of its ability to operate successfully over a wide heat range, the present burner is ideally suited for automatic control. Thus, referring to FIG. 8, a thermostatic sensing unit 90 my be provided fitted within the hollow burner construction and having a springpressed disc 91 at its upper end which bears against the bottom of the cooking vessel 92. The sensing unit 90 may be connected by means of a capillary to the usual type of automatic throttle valve. When the set temperature is reached, the gas passing through the valve is automatically throttled to a point which is just suflicient to maintain the temperature which, at low settings, may correspond to the flame condition set forth in FIG. 5. The result is reliable temperature control and freedom from scorching the contents of the cooking pan when left unattended.

When the burner is used for conventional manual control, it is preferred to block the central opening of the burner partially by means of a disc-shaped insert as indicated at in FIG. 2. The disc is supported in the position shown by a set of integral tripod legs 96, the lower ends of which seat on the shoulder 45 formed in the tubular portion 41 of the burner head. Because the stepped shoulder formed in the head and the size and position of the insert, the secondary air which flows up through the center of the burner is directed outwardly at an angle as indicated at 97 into the region of the burner flame. The total air flow is thus restricted to that required for secondary air so that the amount of heat carried away by chimney action is minimized.

While the present burner is distinguished by safe and stable operation under a wide range of conditions, it is equally distinguished by structural simplicity and ease of manufacture. Since the flange which forms the partition between the two burner chambers form an integral part of the port ring, it will be apparent that the characteristics of the burner may be modified for different types and pressures of gas as well as to meet other specialized operating conditions simply by substituting a slightly modified port ring while leaving the remainder of the burner unchanged.

If desired, the restricting partition 70 may be formed on the lower edge of the skirt 34 of the burner body as indicated at 70a in FIG.11 without departing from the present invention and without aflecting the operation of the burner. This can be done economically since the burner body 32 is a simple, stamped piece permitting a central disc of desired diameter to be punched out of a cup-shaped blank, if desired, as a part of the forming operation. Where the partition is integrally formed with the burner body, the port ring 42 is shallower in the radial direction and such port ring, if desired, may be formed of a flat strip of metal, permitting all of the ports to be punched in a single operation, following which the port ring is rolled into cylindrical shape and its lower edge upset for seating, as shown, on the ledge portion of the burner body. The various parts are formed by simple metal stampings and final assembly consists merely of a telescoping and spining operation.

I claim:

1. In a gas burner for a range having a variable source of air-gas mix, the combination of a burner body of hollower annular construction having a top circular opening bounded by a peripheral ledge which merges into a depending inner skirt portion and having a bottom circular opening alined therewith but of lesser diameter, a burner head having a central tubular portion and a peripheral portion spaced radially outwardly therefrom, said peripheral portion having a continuous series of primary and auxiliary burner ports formed therein and terminating in a necked-down outer skirt portion, said outer skirt portion being dimensioned to mate with the upper opening in the burner body and said tubular .portion being dimensioned to mate with the lower opening in the burner body when the burner head and burner body are telescoped together to form a burner, means for admitting air-gas mix from the source into the burner body, at least one of said skirt portions being inturned and inwardly extending toward the tubular portion of the head so as to provide a narrow annular passageway between the burner body and the head to lower the pressure in the head below the point of blow-away of the flame at high rates of flow and to provide a flow which is evenly distributed about the entire series of ports, said primary ports being horizontally elongated and relatively closely spaced to provide positive carryaround of the flame at low rates of flow, and said auxilary ports being of relatively small diameter and arranged in centered relationship below the primary ports for maintaining the mix ignited at high rates of flow.

2. The combination defined in claim 1 in which the necked-down skirt portion of the head is separated from the peripheral portion by an inwardly directed shoulder which is adapted to seat on the peripheral ledge of the burner body when the burner head and burner body are telescoped together to form a burner.

References Cited by the Examiner UNITED 2,638,976 5/1953 Vixler 158-116 2,682,303 6/1954 Reinhart 158-115 FOREIGN PATENTS 5 211,271 6/1909 Germany.

STATES PATENTS 868,173 5/1961 Great Britain.

Brooke FREDERICK L. MATTESON, 111., Primary Examiner. Baxter 15 81 16 X MEYER PERLIN, JAMES W. WESTHAVER, Wheelock.

Examiners.

Claims (1)

1. IN A GAS BURNER FOR A RANGE HAVING A VARIABLE SOURCE OF AIR-GAS MIX, THE COMBINATION OF A BURNER BODY OF HOLLOWER ANNULAR CONSTRUCTION HAVING A TOP CIRCULAR OPENING BOUNDED BY A PERIPHERAL LEDGE WHICH MERGES INTO A DEPENDING INNER SKIRT PORTION AND HAVING A BOTTOM CIRCULAR OPENING ALINED THEREWITH BUT OF LESSER DIAMETER, A BURNER HEAD HAVING A CENTRAL TUBULAR PORTION AND A PERIPHERAL PORTION SPACED RADIALLY OUTWARDLY THEREFROM, SAID PERIPHERAL PORTION HAVING A CONTINUOUS SERIES OF PRIMARY AND AUXILIARY BURNER PORTS FORMED THEREIN AND TERMINATING IN A NECKED-DOWN OUTER SKIRT PORTION, SAID OUTER SKIRT PORTION BEING DIMENSIONED TO MATE WITH THE UPPER OPENING IN THE BURNER BODY AND SAID TUBULAR PORTION BEING DIMENSIONED TO MATE WITH THE LOWER OPENING IN THE BURNER BODY WHEN THE BURNER HEAD AND BURNER BODY ARE TELESCOPED TOGETHER TO FORM A BURNER, MEANS FOR ADMITTING AIR-GAS MIX FROM THE SOURCE INTO THE BURNER BODY, AT LEAST ONE OF SAID SKIRT PORTIONS BEING INTURNED AND INWARDLY EXTENDING TOWARD THE TUBULAR PORTION OF THE HEAD SO AS TO PROVIDE A NARROW ANNULAR PASSAGEWAY BETWEEN THE BURNER BODY AND THE HAD TO LOWER THE PRESSURE IN THE HEAD BELOW THE POINT OF BLOW-AWAY OF THE FLAME AT HIGH RATES OF FLOW AND TO PROVIDE A FLOW WHICH IS EVENLY DISTRIBUTED ABOUT THE ENTIRE SERIES OF PORTS, SAID PRIMARY PORTS BEING HORIZONTAL ELONGATED AND RELATIVELY CLOSELY SPACED TO PROVIDE POSITIVE CARRYAROUND OF THE FLAME AT LOW RATES OF FLOW, AND SAID AUXILIARY PORTS BEING OF RELATIVELY SMALL DIAMETER AND ARRANGED IN CENTERED RELATIONSHIP BELOW THE PRIMARY PORTS FOR MAINTAINING THE MIX IGNITED AT HIGH RATES OF FLOW.

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