US2311994A - Gas burner - Google Patents

Description

Feb. 23, 1943. c. E. PARKER GAS BURNER Filed March 18, 1940 2 Sheets-Sheet 1 O O O u 0 O Q 0 O 0 e A? Dar/aer- Feb. 23, 1943. c. E. PARKER GAS BURNER Filed March 18, 1940 '2 Sheets-Sheet 2 Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE GAS BURNER Claude E. Parker, Chicago, 111., assignor to Gas Products Corporation, Chicago, 111., a corporation of Illinois Application March 18, 1940, Serial No. 324,470

7 Claims.

The present invention relates to gas burners of the general type used in cooking tops of gas ture, the improvements which constitute the sub ject matter of the'present invention are useful in burner heads generally, whether or notfthey are associated with overlying covers.

Generally stated, one object of the present in vention is to provide a burner head having a series of fuel emission ports arranged in a novel pattern so as to fulfill two generally antithetic requirements, viz: distribution oi. the ports over a maximum portion of the bottom area of a utensil which is large enough to overlie the entire burner, and concentration of a maximum number of the ports beneath a small utensil of only about half the diameter of the larger utensil.

A further object is to provide a burner embodying a novel pattern of port arrangement which is not only such as to afford effectual distribution of flames beneath utensils of widely different sizes, but which is also such as to simplify very materially the drilling operations required in forming the ports, both for individual and gang drilling of the same.

Another object is to provide a burner head of the class set forth embodying a novel arrangement of interiorly located chambers or supply passages for effectually distributing fuel to all of a series of ports, and which is of such character that an unusually high ratio of primary air to raw gas is possible without danger of causing blowing of the flames issuing from the ports, thereby also permitting a wide latitude of adjustment for the primary air intake. 7

Still another object of the present invention is to provide in a gas stove top burner a novel arrangement for propagating flame during lighting, to a plurality of segregated groups of ports which may be, for example, distributed along radial arms on the burner.

Further objects and advantages of the inven- Fig. 2 is a side elevation, partially in section. of the burner.

Fig. 3 is a transverse sectional view of the burner head, taken substantially along the line 3-3 in Fig. 2.

Fig. 4 is a vertical sectional view of the head, taken substantially along the line 4-4 in Fig. I.

Fig. 5 is a detail plan view of the lower section of the head.

Fig. 6 is a horizontal section of the lower portion of the head, taken substantially along the line 6-6 in Fig. 4.

While the invention is susceptible of various I modifications and alternative constructions, I

have shown in the drawings and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend to limit the invention to the specific form disclosed, but intend to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims.

In the instant construction (Figs. 1 and 2) the burner head is made up of complemental top and bottom sections I0 and H, fixed together by ma-- chine screws l2. The whole assembly may be mounted in the cooking top 01' a stove (not shown) in any suitable manner. The burner head sections are desirably made of cast iron and their mating faces are machined or ground flat to insure a tightly sealed joint between them.

Turning first to the construction of the top section I, it will be found that one key feature of the present burner head is the pattern of distribution for the fuel emission ports. In the exemplary construction (Fig. 1) a plurality of ports l5 are arranged in three curved, and in this case arcuate, rows. These rows of ports lie in a common horizontal plane (see Fig. 2) and the rows form, so to speak, inwardly dished or concaved sides of a triangle. Each of the ports slants outwardly at an angle of approximately to the horizontal so that theflames issuing from them will project laterally, as well as upwardly, thus, covering a maximum area of utensil bottom surface. The upper head section III has three radial arms l6 though it is not strictly a star burner but, in fact, partakes of the characteristics of both round and star burners. In the present burner, which is of 9000 B. t. u. capacity, forty-two of the ports l5 are provided in the edges of the arms, fourteen in each of the three rows. Bearing in mind this general pic- 5 ture of the arrangement, attention will now be given to various correlated and more detailed factors in the port layout.

One factor taken into account in the layout of the port pattern is the effective heating of various sizes of utensils. The perimeter of a utensil bottom of six inch diameter, which may be taken as a medium size, is indicated by the dot-dash line circle L in Fig. 1. It will be observed that it passes through the end portions of the burner head arms and at a sufficient distance from the ends of the rows of ports that fiames'issuing even from the end ports in the row will be beneath it. Accordingly, all forty-two of the ports ll shown are well within the confines of the utensil bottom so that flames issuing from them play directly on the bottom of the utensil. Furthermore, the

ports are distributed throughout substantially the entire area of the bottom of the utensil so that its contents is heated evenly and with a maximum effectiveness of heat transfer as distinguished from the hot-spot center concentration of a conventional round burner.

In addition to the heating of large utensils, however, the pattern of ports in the illustrative burner head is also such as to accomplish the effectual heating of a much smaller utensil of, for example, only about half the diameter of the large utensil indicated at L. The perimeter of such a small utensil, of approximately three inches diameter, is indicated in Fig. 1 by the dotdash line S. Measuring cups, small coffee pots and the like of this size are, of course, fr equently heated on stove top burners and it is to take care of this condition that the provision is made in the pattern of ports for the heating of such small utensils. It will be observed in Fig. 1 that the rows of ports I are concaved inwardly to an extent that the central portion of each row of ports lies well within the circle S. In particular, twelve of the forty-two ports l5 lie wholly within the circle S and six more of them are at its edge so that flames issuing from these ports will play on the bottom and sides of the small utensil. Consequently, a little better than forty per cent of the main ports are positioned to heat effectually even such a small utensil. Incidentally it should also be noted here that the center portion of either a large or small utens'il is heated by flames issuing from centrally disposed lighter slots, hereinafter described, and which themselves use nearly twenty-five per cent of the fuel supplied to the head. Hence, a total of about fifty-five per cent of all fuel supplied is used in heating even a small utensil.

A second factor taken into account in the port layout pattern is the prevention of the flame crowding or overlapping. For efficient combustion it is important that the flames should not impinge upon each other, for otherwise there will be an insufficiency of secondary air enveloping the flames at their points of merger, with consequent incomplete combustion. Since the relative alinement of the flame ports, to prevent overlapping or crowding, depends primarily upon the relative alinement of the port axes or center lines, this problem is closely correlated with that of drilling the ports. In other words, the number of work piece repositioning movements required during drilling, and the possibilities of ganging the drills, also depend upon the relative alinement of the individual port center lines.

In the instant burner head the two correlated problems noted just above have been solved by arranging the center lines of the ports l5, in each arcuate row, to radiate from a common point 10- making this radius of curvature substantially greater than the maximum length of any flame cated substantially at the center 0: the radius of curvature for the particular row, and also by issuing from the burner even when its fuel supply is full on. In Fig. 1 the center lines of the ports 15, in both the upper and right hand arcuate rows, have 'been indicated by the dot-dash lines 11. When fully projected these sets of center lines merge at centers substantially coincident with the radii of curvature for the respective port rows. Since this radius of curvature is substantially greater, in fact, nearly double, the maximum length of any flame issuing from the ports there is no danger of crowding or merger of the flame with consequent imperfect combustion. The ports themselves are spaced apart sufficiently to prevent merger of the flames adjacent their bases, a spacing of one-fourth of an inch between center lines I! for the ports having been found satisfactory in the illustrative head.

Either gang or single-hole drilling is greatly simplified by the port arrangement just described. In either case only three complete repositioning movements of the head are required, one for each rowof ports. When each of the three successive curved sides of the head is presented to the drilling mechanism, successive holes can be drilled if single-hole drilling is used by simply indexing the head step by step around the center at which the longitudinal center lines of the ports merge and which is substantially coincident with the center of the radius of curvature for the row. Even more simply, a gang of drills can be arranged to drill alternate holes in the row. In the latter case half of the holes in a row are drilled and then the head is indexed to position it for drilling the remainder of the holes in the row. This gang drilling of alternate holes is desirable because the close spacing of the ports makes difficult the simultaneous drilling of adjacent ports. I

Simplicity of burner head shape, and consequently minimization of cost, are also afforded by the port arrangement set forth above. To be particularly noted in this connection are, first, that smooth contours for the head simplify casting and, second, to avoid creeping the drills used in forming the ports must lie at right angles to the surface which they enter as the drilling starts. In the present construction the ports l5 are fashioned in thickened edges l8 of the generally triangular head section I0. These edges present generally smooth arcuate outer faces slanting upwardly and inwardly at an angle of about forty-five degrees. That the faces of these edges can be of such simple and smooth contour, as distinguished from, say, a series of stepped faces distinguished longitudinally along the edge, is due to the fact that the port center lines I! all project from points substantially coincident with the centers of the radii of curvature for the edges 18. Since the center lines are so located, the drills will enter the-edge face at right angles in each instance, thereby obviating any creeping of the drill nose. The smooth contour of the ported edges 18 not only minimizes casting cost but also simplifies cleaning of the head during use.

Still another factor taken into account in the port layout is the lateral spacing of the port rows with respect to each other so as to afford sufficient thickness of metal for optimum port depth and room for adequately dimensioned supply chambers within the head. As to port depth, it

is desirable that the ports be quite deep, for example, about five-sixteenths of an inch, in order to reduce popping when the burner is lighted or turned oil. The requisite thickness of metal in the ported ridges I8 (see Fig. 2) to achieve the desired port depth entails in itself some spacing of the ends of the port rows from each other. As to fuel supply, the burner arms I6 are chambered or hollow to form gas supply passages to the ports I5, and to make these arm passages large enough so that there will be no starving of the end ports in the rows, the arm chambers must be of substantial width. A lateral spacing between the end ports at a (Fig. 1) of about one and three-sixteenths inches has so far been found to be about the minimum permissible.

That three arms, as distinguished from a greater or lesser number, is very important in the layout of the burner disclosed will be apparent from a correlation of the various factors set forth above. If only two arms, and, hence, two rows of ports, were used the distribution of ports over the bottom of a large utensil would be inadequate. n the other hand, if four or more rows of ports were used one of two difficulties would arise. First, if the same radius of curvature as is here disclosed were retained for the port rows, their central points would be displaced so far outward from the center of the head that few or none of the ports would fall beneath the small utensil S. Second, if the four rows were deeply concaved, that is, a smaller radius of curvature used for them, in order to bring an adequate number under the small utensil, there would be crowding and merging of the flames. By using the three curved rows of ports substantially, as disclosed, these various factors have all been reconciled.

The burner head as shown in Fig. 1, with its forty-two ports, has been designed for standard 9000 B. t. u. capacity. It is, however, a very simple matter to convert it for the alternative standard 12,000 B. t. u. capacity. For this latter purpose twelve additional ports are drilled in the head, two at each end of the respective arcuate rows. Otherwise, no change in construction is required, the dimensions of the interiorly located chambers or gas passages, hereinafter described, being ample to accommodate the increased load.

Turning now to the arrangement of interiorly located fuel supply passages in the head, it will be observed (Fig. 3) that the arms I6 of the upper head section I0 are hollow. These arms each define an interior chamber I9 (see also Figs. 2 and 4) which tapers toward the outer end and which is split into two parts at its inner end so as to have a general V-shape. The ends of the Vs are merged so that the chambers I9 form a continuous triangular chamber or channel having a maximum transverse section at its ends (Fig. 3). The arms I5 also taper upwardly on their lower sides (Figs. 2 and 4), however, and inasmuch as the chambers I9 taper correspondingly on their lower sides they are of maximum vertical section at the points of merger between the ends of the Vs.

The lower head section N (Fig. 6) defines a generally annular fuel distribution passage or chamber 20. Communication is established between the lower annular passage and the upper continuous triangular passage I9, I9, I9 through three triangular ports 2|, 22 and 23 (Fig. 5) in the upper face of the lower section it and a complemental set of ports 24, 25 and 26 (Fig. 3) in the abutting bottom face of the upper head section I0. These latter ports are formed at the low points of the depressions formed in the bottom of the passages I9 adjacent the latters points of juncture. The registering ports thus constitute, in effect, three sets of short, vertically extending, intercommunication passages between the lower passage 20 and the upper passages I9. Accordingly, the gaseous fuel flowing around the annular passage 20 rises through the three sets of registering ports and spreads laterally through the triangular chamber formed by the three merged passages I9 and is finally emitted through the ports I5, which project from these latter passages.

For supplying a mixture of gaseous fuel and primary air to the distribution chamber 20 a Venturi tube is utilized (Fig. 2). This Venturi tube is desirably cast as an integral part of the lower burner head section II and is reentrantly bent to partially encircle the latter (Fig. 5). Thus the Venturi tube 27 extends along, and is integral with, the right hand side of the lower burner head section, though there is no communication between this portion of the Venturi tube and the passage 20. The Venturi tube sweeps all around to the back of the burner head in a smooth curve and finally terminates with its exit throat 28 facing into the lower burner head section II along a diameter of the latter. Consequently the fuel and air mixture leaving the Venturi tube exit throat 28 is discharged in two divergent streams, indicated by the arrows 29 (Fig. 6) and which sweep in opposite directions about the annular passage 20. It will be observed in Fig. 6 that these two streams, indicated by the arrows 29, meet in the annular passage 20 at a point diametrically opposite the exit throat 28. The normal tendency of the merged streams would be to turn laterally or, in other words, to surge upwardly into the upper burner head section. Direct upward flow at this point is prevented, however, by a bafiie 3'! (Fig. 5) which in the present instance is the forward leg of the webbing in the lower section II which separates or defines the ports 2| and 22 on opposite sides of this point (Fig. 5). Consequently, the streams of gaseous fuel and air mixture, being baflled in this manner, are compelled to turn substantially at right angles and flow uniformly through all three of the ports 2|, 22 and 23 so that the mixtluredis evenly distributed throughout the burner Further insurance of uniform distribution of the gas-air mixture to the top section chambers is afforded by the proportioning of the port areas and other restrictions imposed on the three streams of gases flowing upward respectivelythrough the ports 2 I 22 and 23 (Fig. 5) Notable in this connection is the smaller effective area of the ports 2| and 22 as compared to port 23. The side walls of the chamber 20, being inset closely beneath these ports 2| and 22, partially close them. Additionally the flow of gas to them is partially restricted by the lateral narrowing of the channels for the branched streams of gases in the chamber 20 (see Fig. 6) as they approach the ports 2|, 22. These factors combine to impede the flow of gases to and through the ports 2|, 22 so as to match that through the port 23. In the absence of such impediment the flow through port 23 would be less than through the other two since the direction of the gas entering the chamber 20 tends to carry them to the far ports 2|, 22 rather than permitting it to rise directly through the port 23.

Gas is supplied to the Venturi tube 21 in the usual manner from a manifold 30 (Fig. 2) under the control of a manually operable valve 3|. Adjustable shutters 32 at the entrance end of the Venturi tube regulate the proportion of primary air which is mingled with the entering stream of raw gas. By locating the Venturi tube 21 to encircle the base of the burner, as shown, the tube can be made of full length and yet its mouth is located beneath the head itself. The resulting short overall length makes it possible to position the burner close to the front of the stove (Fig. 2) without sacrifice in the length and effectiveness of the venturi.

In actual use it has been found characteristic of the present burner that it is capable of an extreme latitude of primary air adjustment without so-called blowing of the flames issuing from the main ports i 5. In gas burners of the'Bunsen type, and of which general type the present burner is one, as the amount of primary air is gradually increased, from a minimum required to support any combustion, the flame changes gradually from a so-called soft lazy form to a hard form in which the jets of flame have a pale blue, rigid or pencil-like, appearance. In the course of this change the efficiency of combustion correspondingly increases and it is, therefore, very desirable that as hard a flame as possible be maintained. The diiflculty has heretofore been, however, that the increase in primary air, required to obtain a hard flame, also resulted in severe popping or minor explosions during lighting and furthermore caused somewhat of a roaring noise during operation and a lifting of the flames from the ports, this latter being ordinarily referred to as blowing of the flames. In the present burner, on the other hand, an otherwise prohibitive amount of primary air can be admitted without any such blowing or popping during lighting. In other words, even with the shutters 32 open wide to'admit a large amount of primary air so that a high efliciency of combustion is achieved, the burner lights smoothly without any popping and the flame jets issuing from the ports l5 are of hard, stable form though they display no tendency to blow. In particular it has been found possible to use as much as seventy-five percent primary air as contrasted with a maximum of about fifty-five percent in prior burners.

The factors which contribute to this remarkable improvement in operation are, for reasons obvious enough from the character of the apparatus, difficult to segregate and analyze. It is believed, however, that the arrangement of baffles and passages, and consequent restrictions on and control of gas flow, within the burner head are of primary importance. In general, the baffles and flow passages are such that the fuel and air mixture must change its direction of flow radically several times within the head and a substantial expansion takes place in the upper head section as the gas passes through the restricting ports 2|, 22, and 23, all before it issues from the ports l5. As a consequence, most of the velocity head of the strong draft of primary air is dissipated before the fuel and air mixture leaves the ports. Particularly notable in this connection is the fact that the circular swirling motion of the gaseous mixture entering the annular chamber 20 is broken up and the gas forced to move upwardly at right angles when it leaves this chamber. Even after this change in direction of flow the gas must make still another right angle turn into the ends of the passages l9 before reaching most of the ports l5. Coupled with this tortuous path arrangement is the fact that a large volumetric capacity is provided by the merged chambers l3 within the upper portion of the head so that despite the baffling of the gas there is always an ample volume ofthe latter available at the ports and a substantial diminution in velocity head is accomplished by expanding the gas into these chambers 19 through the restricting ports 2|. 22 and 23. Furthermore, the arrangement is such as to insure thorough mixing of the gas and primary air within the head and to minimize the static pressure within the head. Both of these are important, ininsuring quiet operation. In connection with minimization of static pressure it should be particularly noted that the ports 2|, 22 and 23, in conjunction with the restricted passageways on each side of them provide a substantial restriction between the entrance throat 23 and the chamber in the upper head section, thereby apparently largely dissipating the effects of changes in pressure of the gas supply. In other words reflection of this gas supply pressure changes, in the static pressure in the head, is substantially eliminated.

Two factors which would otherwise render diflicult the lighting of the burner shown have been overcome by a novel arrangement of flame propagation means. The first of these factors is the segregation of the main ports l5 into three separate rows for distribution of flames about substantially the entire periphery of the head. The second is the provision of an open center for the head through which an updraft of secondary air is admitted. Though the provision of supply of this secondary air is highly desirable from the standpoint of efficient combustion, it obviously makes difficult the propagation of flame between the rows of ports l5 which are located on substantially opposite sides of the open center through which the secondary air is flowing upwardly. Thus, upon reference to Fig. 1, it will be seen that if gaseous fuel issuing from a lighter port 33, when the gas supply is turned on, is ignited by a lighter mechanism (not shown) of conventional and well known form that the resulting flame from the lighter port can readily light the adjacent arcuate row of ports IS. The flame cannot well be propagated across the ends of the arms l6, however, because of their width and also the fact that the ports are directed laterally outward so that those on opposite sides of an arm face away from each other. This leaves the possibility of propagating flame across the head but there the uprush of secondary air interferes.

As a means of propagating flame across the open center of the head to the opposite rows of ports IS, a star shaped integral web 33 has been provided in the open center of the upper head section l0 (Figs. 1 and 3). The web has the same number of arms as the burner head but it is in effect skewed with respect to the latter so that the web arms project intermediate the burner arms l6 and merge with the burner casting adjacent the points of juncture between the burner arms. The center of the web 33 is solid but the outer portions of the arms are hollow, their chambered interiors communicating with the passages [9 in the burner arms. Along the tops of the web arms are fashioned three saw slots 34, the'metal be n thickened by suitable ridges along the slot edges so that the depth of the slots are substantially the same as that for the main ports l5, namely about 1; inch. The slots 34 extend well in toward the center of the web 33. Hence, when a lighter mechanism (not shown) is actuated to ignite the fuel emitted from the initial lighter port 38 (Fig. 1) so that the latter will ignite fuel emitted from the adjacent center ones of the ports l in the upper row (as viewed in Fig. 1) it will also ignite the fuel issuing from the adjacent one of the slots 34. Thereupon, the fuel issuing from the upper row of ports I5 is ignited at successive ports along the row with the flames spreading in both directions from the center. At the same time the flame flashes across the center of the head, along the slots 34, and the other two rows of ports l5 are similarly ignited from their centers progressively toward their ends. Flames continue to issue from the slots 34 during the operation of the burner and serve incidentally to heat the center portion of a utensil placed above the burner.

Of particular importance in the construction of the web 33 is the provision of comparatively wide arms on the web and the completion by it of a solid structure across the open center of the head which constitutes a baflle beneath the slots 34. By virtue of this arrangement the updraft of secondary air is deflected laterally so that it does not at any point interrupt the lines of flame propagation between the several slots 34. In this way the secondary air is prevented from lifting or blowing the flames issuing from the slots 31 although an adequate amount of secondary air envelops these flames to support efficient combustion.

A minimization in over-all dimensions for the head is accomplished by the form of secondary air and gas passages shown. It will be seen in Fig. 5 that the lower burner head section II has a Y-shaped opening 35 in its center while in Figs. 1 and 3 it will be seen that the upper section It has three generally central openings 36 which extend upwardly and outwardly from the ends of the Y-shaped opening 35. The hole 35 (Fig. 6) in the lower section I I is defined by the inner wall of the annular chamber 20, and this wall is flared outwardly at three points in the form of webs or baflles'3'l (Fig. 5). These webs define the the laterally flaring legs of the Y-shaped hole 35 and also overlie the otherwise open top of the chamber 20 to delimit the ports 21, 22 and 23. In the upper head section II) the registering holes 36 are similarly slanted or flared outwardly so that they are actually located fairly well up in the burner arms l6 and are embraced by the V- shaped end portions of the gaseous fuel passages [9 (Fig. 3). Hence, at the top face of the lower head section II we find alternate gas and secondary air openings formed by the ports 2|, 22 and 23 and arms of the Y-shaped opening 35. Similarly, in the upper section Ill the air and gas chambers alternate with each other about the center of the head. This interleaving of air and gas passages assures maximum compactness while at the same time accomplishing the desired control of the direction of flow for the respective fluids. Secondary air flows upwardly from beneath the head, through the hole 35 and passages 36, to the tops of the burner arms where it supplies flames issuing from the main ports l5.

The initial lighter port 38 previously noted (Figs. 1 and 2) is fashioned in a lug 39 integral with the upper head section I0 and secured by one of the screws 12 to the lower section. Registering with the port 38 is a port 40 in the lower section (see also Fig. 4) and which leads from the exit end of the Venturi tube 21. Whenever the valve 3| is turned on to start the burner gaseous fuel is thus supplied to the port 38 where it is ignited in the usual manner. By forming the port 38 in the lug 39 the exit end of the port is high enough, in relation to the main ports l5 above it, that the flame from the lighter port can reach and light them without having to place an extension tube or the like on the lighter port.

I claim as my invention:

1. A gaseous fuel cook stove top burner head of generally triangular form with the respective edges of the triangle concaved to present three inwardly curved lateral edges on the head, the central portions of said concave edges lying well within the area of a first circle which is concentric with and of approximately half the diameter of a second circle concentric with the head and passing through the outer ends of said edges, and said head having a plurality of fuel emission apertures therein distributed along said edges and with suflicient of said apertures to constitute approximately forty per cent of the aggregate area of the same located within the confines of said first circle.

2. A gaseous fuel cook stove top burner head of generally triangular form with the respective edges of the triangle concaved to present three arcuate lateral edges on the head, the central portions of said concave edges lying well within the area of a first circle which is concentric with and of approximately half the diameter of a second circle concentric with the head and passing through the outer ends of said edges, said head having fuel emission means distributed along substantially the entire length of said edges, said edges of the head being spaced apart at the ends of said arms a substantial distance, and the arms of said triangular head being chambered in their end portions between the spaced ends of said edges along which said fuel emission means is distributed. 1

3. A burner head of the type set forthhaving a plurality of rows of fuel emission ports therein arranged to face generally laterally outward from the head and lying in a common horizontal plane, each of said rows being arcuate in form, the center lines of the ports in each row radiating from a single point located substantially at the center of the radius of curvature for the row, and all of said centers lying outside a circle circumscribing said head.

4. A burner head of the type set forth of triangular shape and having three rows of fuel emission ports therein located in respective sides of the triangle and arranged to face generally laterally outward from the head, said ports lying in a common horizontal plane and facing generally laterally outward as well as upward, each of said three rows of ports being arcuate in form, and the center lines of the ports in each row radiating from a common center located at substantially the center of the radius of curvature for the row, said radii of curvature being centered at points lying a substantial distance outside a circle circumscribing the apexes of the triangular head.

5. A gaseous fuel burner comprising a plurality of radially extending hollow arms projecting from a central body portion with an open center, said arms having rows of ports therein adjacent their outer edge portions and extending between adjacent arms and separated from each other at the outer ends oi such arms, a star shaped integral web on said central body portion and located in the open center of the latter with the arms of the web joining the periphery of the body about such open center at points alined with the juncture points of the bases of adjacent arms, the outer portions of the web arms being hollow and opening into the interior of the head, and the tops of said web arms being slotted longitudinally to form a chain of fuel emission apertures joining the several rows of ports across the open center of the head. 1

6. A gaseous fuel burner comprising a plurality of radially extending hollow arms projecting from a central body portion with an open center, said arms having fuel emission apertures therein along their outer sides and separated at the ends of the arms, a star shaped integral web on said central body portion and located in the open center of the latter with the arms of the web joined to the periphery of the body about such open center, the number of web and burner arms being equal, the outer portions of the web arms being hollow and opening into the interior of the head. and the tops of said web arms being apertured to form a chain of fuel emission apertures joining, across the open center 0! the head, the segregated first mentioned fuel emission apertures on the outer sides of said arms. and said web being continuous across said open center to prevent a current of secondary air from interrupting the propagation of flame along said chain of fuel emission apertures.

7. In a gas burner, the combination of a'body having an open center portion for the updraft of secondary air through such center, said body continuous fuel emission aperture arrangement along its top for projecting flame, during lighting, between groups of said ports located generally on opposite sides of said open center, said web projecting laterally from the aperture in its top to protect flames issuing from the latter

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