US2253178A - Oven burner for gas ranges - Google Patents

Description

Aug. 19, 1941. J. F. HENNES'SY OVEN BURNER FOR GAS RANGES Filed June 4, 1938 2 Sheets-$heet 1 VIII/II YIIIIIIIIIIIIIII: W

J. F. HENNESSY I QVEN BURNER FOR GAS RANGES Filed June 4, 1938' 2 Sheets-Sheet 2 JLMW" W2? Patented Aug. 19, 1941 t tartar team I Y D. Roper Corporation} Rockford, 111.; a corpora- Atstaranitsei, 193s, stssi-mti1aa c cl ims.- curse-9'9) A This invention'relates to gas burners, and has particular reference to a new and improved oven andbroiler burner for gas'ranges. The principal object of my invention is to provid a burner'iwhich is capable of maintaining a lower oven temperature on turn-down than has heretofore been obtainable with other burners, and which is capable of heating up to the desired high oven temperatures in much less time than was required customarily with other burners.

An important feature ofthe present burner is the fact that it is so designed that it may be used for oven operation alone or as a combination oven and broiler burner. The burner of my invention has 'a turn-down ratio of at least 10 to 1, which means that it is capable of supporting combustion on'a very low input, but is nevertheless capable of handling a maximum inputten or. more times the minimum input. To fulfill these'requirements necessitated diminishing the total number of ports from about one hundred and forty (140) to about eighty (80), and the burning of the maximum input with the diminished number of ports in the confined space allotted to the oven burner naturally presented difficult problems as to minimum flame communication; good aeration of "the flames on maximum input, as well as "goodheat distribution. A salient feature of my invention is the manner in which all of the ports of the burner are drilled close together to insure good flame communication on minimum input, but are at an angle to each other so that the distance between the center lines of adjacent "ports increases in proportion to the size of flame so as toallow for good aeration on maximum input, good aeration being especially necessary due to the loss of primary air injection caused by the reduction in number of ports. V In accordance with another object of my invention, the burner has adouble arcuate, generally oval or elliptical shaped body with the ports on one are radiating from one center and the ports on the other are radiating from another center on L the longitudinal center line of the burnerso that adj acent ports in either row are in divergent relationship. This shape of burner furthermore insures even heat distribution. The invention is illustrated in the accompanying drawings, in which-- i Fig. 1 is a plan view of an oven burner made in accordance with my invention;

Fig. 2 is a fragmentary view of theburner on a larger scale, lookingatthe bottom. thereof and showing a portion in horizontal section;

Figs. 3, 4, and 5 are sections on the correspondingly numbered lines of Fig.2; it i T Fig. 6 is a sectional detail on the line'li fi of Fig; 1 on the same scale as Figs. 3 to 5; r i i Fig. '7 is an enlarged sectional detaihof the mixer, taken on'theline T- 'I ofiFi fli f Fig. 8 is :a cross-section on the line 8-8 of i -Land M 1 a Fig.9 is a view looking at the bottom of the mixer, showing the single adjustable closur for the two openings thereof. 1.: l

The same reference numerals are applied-to corresponding parts throughout the views.

The burner has a double arcuate, general-1y oval or elliptical shaped body ll], the one arcuate periphery I I being struckfrom the center 12. and

the other arcuate periphery l3 being struck from the center l4, and both centers being on the longitudinal center line w-b on which the mixing tube 15 also lies. The transverse center line c-d passing through the points of intersection of the arcs l l and l3 has the burner supporting lugs l6 and I"! lying thereon, these lugs being preferably cast integral with the burner body. The mixing tube l5 isypreferably'cast separate from the burner bod'y and suitably secured in a neck [8 which projects radially outwardly from the middle of the arcuate portion l3. The inner periphery IS on the inlet side of the burner body is struck on an arc in eccentric relation to the 'arc I3, so that thecross-sectional area of the gas passage 10a is reduced gradually from the inlet neck I8 toward the opposite ends of the burner. In like mannenthe inner periphery 20 on the side-of the burner body opposite the inlet neck [8 is struck on an arceccentric relative to the are l l,-so that the rest of the gas passage Illa. tapers" gradually from theopposite ends of the burner towardthe middle (see Fig. 2). In that Way, the pressure at all of the ports is substantiallyequalizedand the flames are of substantially uniform size, instead of being larger nearest the inlet neck 18 and smallest at the points most remote therefrom. The gas discharged into the burner by a nipple 2| which extends into the mixer 22 on the end of the mixing tube l5, and primary air is inje cted with the gas to form a combustible mixture burning with'a Bunsen flame. The mixer may be of any suitable type, but lprefer onefconstructed along the novellines disclosed in Figs. 7 to 9, as hereinafter described.

The present burner has be n designed primarily with a View to, greater flexibility, that is, it can operate to maintain a much lower temperature on minimum input than has been ssible with other oven burner constructions and ca'n,'on the other hand, heat up *an'oven to the highest'temperature desiredin much less time than is re: quired' with other oven burners a): conventional construction with "which I am familiar. The present'burner is known "as a low'temperatur'e oven burner, because it can maintain temperatures "as ilowas 220 to 250 "1 whereas the'low poin was'jheretofore about'325 'F. 'rh'e in urger capahle of supporting eassess "an-input of 2400 Bit. ui/hour, or le'sa and is capable of handling a maximum input of 24,000 B. t. u./hour, or better, which means that the burner has a turn-down ratio of at least 10 to 1. In orderto meet these requirements, it has been necessary to diminish the total number of ports, cutting down from about one hundred and forty (140) ports, which is the average on the conventional type oven burners, to approximately eighty (80) ports, as required for the low temperature performance of the present burner. It goes without saying that a burner having only eighty (80) ports must be designed for very efiicient operation to burn an input of 24,000 B. t. u./hour, or better, in the confined space in an oven. With so few ports, it is obvious that there is a greatly increased volume of gas discharged from each port, and one would therefore have to increase the distance between ports to allow proper aeration, but that would make the burner unsafe on turn-down, because of poor flame communication. A burner with Widely spaced ports would also not light properly from port to port. The burner of my invention has been designed to meet the requirements stated, not only as an oven burner, where there is plenty of head room available under the oven compartment, but also as a combination oven-broiler burner operating in a cramped space. This burner has good lighting and good flame communication on turn-down and also good aeration on turn-up. In accordance with my invention, there are two external series of ports 23 and 24 on the two arcuate halves of the burner body, the flames from these ports being indicated by the dotted lines at 23 and 24, respectively, in Fig. 1. The ports 23 all radiate from the point [2, and the ports 24 all radiate from the point 14. The row of ports 24 is interrupted at the neck I8, as indicated by the gap in the series of dotted center lines 24' in Fig. 1. Now, the distance between the centers of adjacent ports in both rows is the same, the distance being small enough to insure good lighting from port to port around the burner and good flame communication on turn-down. Despite this close spacing of the ports, the jets do not tend to blend near the burner into one sheet of flame and thus prevent good aeration, owing to the fact that the ports are in mutually divergent relationship, as indicated by the radial center lines Ho and Ma for ports 23 and 24, respectively, extending from the centers [2 and I4 in Fig. 1, the included angle between the center lines of said ports being about 35 or 3.6". The point is that the gas, after discharge from the ports, expands and the diverging direction of the streams allows for this expansion, while at the same time permitting good access of secondary air to the individual streams. There are external peripheral ledges 25 and 26 provided by annular ribs cast integral with the body ID of the burner above the ports 23 and 24, asclearly indicated in Figs. 2 to 5, and the gas issuing from the ports collects under these ledges to insure good flame communication on turn-down, so that there is no difficulty in lighting the burner. There are two ports 21. at opposite ends of the burner on the center line cd, as indicated by the dotted center lines 27 in Fig. 1, and the jets from these ports serve to light across the ends of the burner from the one row of ports 24 to the other row of ports 23, or vice versa. As clearly appears in Fig. 2, the end port 21 bisects the angle between the endmost ports 23 and 24 of the two arcuate series of ports. In that way, the'distance between these endmost ports 23' and 24, which would be too great for proper flame communication around the ends of the burner, is reduced to the point where good flame communication is assured- The end ports 21, as clearly illustrated in Fig. 6, are offset upwardly in relation to the plane of the ports 23 and 24 in the depressions 28 formed beneath the brackets l6 and I1 between the ends of the ribs defining the ledges 25 and 26. The gas collecting in these depressions insures better lighting across the ends of the burner. The ports 23 and 24 are inclined downwardly at an angle of approximately 10 from the horizontal, as shown in Figs. 3 and 5, so that the outer ends of the ports are at a low elevation, even though the bottom Wall of the burner is fairly thick, and so that the inner ends of the ports are located well above the top of the bottom wall to insure easy entrance of gas thereto. The end ports 27, being on a higher plane, are inclined to a greater degree to compensate for this and thus bring the flames therefrom into about the same plane with the flames from ports 23 and 24. Ports 29 provided along the inner periphery of the burner body adjacent the inlet neck I 8 are also inclined downwardly, as illustrated in Fig. 3. These ports 29 are lighted through a slot 30 extending across the bottom of the burner to establish communication between the row of ports 24 and the row of ports 29. The center lines 29' appearing in Fig. 1 indicate the flames from these ports, which will cause suflicient air movement upwardly through the center of the burner and outwardly over the top thereof to improve aeration above the jets issuing from ports 23 and 24, even though the burner may be set up close to an oven bottom. These ports 29 also take the place of ports omitted on the external periphery of the burner at the inlet neck i8, whereby to insure uniform heat distribution.

In operation, the burner is lighted usually at one of the pointed ends and the flame travels in both directions from the port 2'! along the rows of ports 23 and 24 and finally the ports 29 are lighted by the flame propagated across the bottom face of the burner along the slot 30. The ledges 25 and 26 aid in flame communication, and while the burner is usually set with the ports beneath the ledges, as in a broiler oven, it may, as previously indicated, be used inverted, under a baking oven. With the burner inverted, it is found that the ledges 25 and 26 still aid materially in good flame communication. Good flame communication is also attributable to the close spacing of the ports, as previously pointed out. The close spacing, however, does not interfere with good aeration, because the jets diverge relative to one another along radial lines from the centers l2 and I4, so that the distance between the center lines of adjacent jets increases as the flames project outwardly more and more from the burner with greater and greater turn-up. The condition never arises, therefore, where the jets blend into one sheet of flame with resultant poor combustion due to poor aeration. At each degree of turn-up it will be found that all of the jets enlarge to substantially the same size, owing to the fact that the pressure within the burner body is equalized by reason of the gradual reduction in the crosssectional area in the gas passage away from the inlet neck l8.

The mixer 22 is made U-shaped so as to provide two air inlet'necks 3| and 32 on opposite sides of the gas discharge'nipple 2|, which projects through a hole 33 in the vertical front wall 34 of the mixer and discharges into the center of the bell end 35 of the mixing tube :5. The air therefore is not only more efficiently entrained with the gas, because it is drawn in from both sides of the gas stream, but there is a better opportunity for good mixture of the gas and air in the tube l than where the primary air is drawn in from one side of the gas stream. The same amount of air is admitted through both necks, because the closure plate 36, which is a channel-shaped sheet metal stamping with longitudinal flanges 3'! abutting the opposite sides .of the necks 3| and 32, leaves the same width of opening into each neck in any position of adjustment of the closure plate transversely with respect to the ends of the necks. The one opening 38 into the neck 32 is afforded alongside the end of the closure plate, as clearly appears in Figs. 8 and 9, and the other opening 39 into the neck 3! is provided through an opening 40 provided in the web of the plate 33. A clip 4| fastened by means of a screw 42 onto the end of the neck 3! serves to clamp the plate 33 in adjusted position.

It is believed the foregoing description conveys a good understanding of the objects and advantages of my invention. The appended claims are drawn with a View to covering all legitimate modifications and adaptations.

I claim:

1. An oven burner for a gas range comprising a generally oval shaped tubular body the outer peripheries of opposite sides of which are struck on arcs intersecting at opposite ends of the major axis of the body, the arms being on substantially equal radii that are nearly as long as the minor axis of said body and struck from spaced points on said minor axis near the opposite ends thereof, and a mixing tube connected to said body, both arcuate outer peripheries having ports provided in equally laterally spaced relation therein, the ports in each periphery being on radial lines from the center of the arc thereof so that all adjacent ports are in divergent relation on small included angles.

2. An oven burner for a gas range comprising a generally O-shaped tubular body the outer peripheries of opposite sides of which are struck on arcs intersecting at opposite ends of the body, both arcuate outer peripheries having ports provided in laterally spaced relation therein, the

ports in each periphery being on radial lines.

from the center of the arc thereof so that adjacent ports are in divergent relation, and said body having ports provided .in the outer periphery thereof at the points of intersection of the arcs of the arcuate opposite sides of the body, each of said ports being on a line bisecting the angle between the adjacent endmost. radial ports disposed on opposite sides thereof, the two series of radial ports being disposed in a common plane, and the other ports at the opposite ends of the burner being disposed in another plane in closely spaced relation to the first named ports, the burner including projecting peripheral ledges in a common plane parallel with but spaced from the plane of the radial ports and substantially coincident with the plane of the other ports at the ends of the burner, the ledges terminating in spaced relation to the latter ports, and said burner further including supporting brackets on the opposite ends of the burner in spaced relation to the end ports and forming gas pockets around the end ports with the adjacent ends of the ledges.

3. An oven burner for a gas range comprising a generally oval shaped tubular body the outer peripheries of opposite sides of which are struck on arcs intersecting at opposite ends of the major axis of the body, the arcs being on substantially equal radii that are nearly as long as the minor axis of said body and struck from spaced points on said minor axis near the opposite ends thereof, a mixing tube communicating with and extending from the outer periphery of the body intermediate the ends of one of the arcuate sides to deliver a combustible mixture of gas and air to said body, both arcuate outer peripheries of the body having ports provided in equally laterally spaced relation therein, the ports in each periphery being on radial lines from the center of the arc thereof so that all adjacent ports are in divergent relation on small included angles, and said body having a row of ports provided in laterally spaced relation in the inner periphery thereof adjacent the point of communication of the mixing tube with said body.

4. A gas burner comprising a hollow generally oval shaped body whose opposite side portions are of arcuate form struck on radii that are approximately equal to half the length of the major axis of the oval shaped body, said side portions being each drilled radially into the outer periphery to provide a continuous series of large closely spaced ports in outwardly divergent relation, every one of said ports having substantially the same small included angle with ports on opposite sides thereof, whereby to insure good aeration of the jets on turn-up.

5. An oven burner for a gas range comprising a generally elliptical shaped tubular body whose outer peripheries are struck on arcs intersecting at opposite ends of the major axis of the body, both arcuate outer peripheries having ports in a common horizontal plane provided in equally laterally spaced relation on radial lines from the centers of said arcs, there being at least one intermediate port provided in each end of the burner between the adjacent end ports of the two arcuately arranged series extending substantially parallel to the major axis of the body in a plane above the plane of said other ports, supporting brackets extending outwardly from the opposite ends of said body along the major axis thereof, and means including adjacent portions of said brackets forming gas collecting pockets on the ends of said burner arranged to catch gas issuing from the adjacent end ports of the arcuately arranged series as well as from said intermediate ports.

6. A low temperature oven burner, comprising a hollow generally oval shaped body whose opposite side portions are of arcuate form struck on radii that are long in relation to the distance between said side portions measured along the minor axis of the oval, said side portions being each drilled radially into the outer periphery to provide a continuous series of ports, all neighboring ports being in divergent relation with an included angleof approximately three and onehalf degrees therebetween, and all of said ports being relatively enlarged but relatively closely spaced, the close spacing insuring good flame communication on turn-down and the divergent relationship of the ports insuring good aeration on turn-up.

JOHN F. HENNESSY.

? Patent No. 2,255, 78

CERTIFICATE OF CORRECTION.

August 19, 1911.1;

JOHN F. HENNESSY.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows: Page 5, first column, line 56, claim 1, for the word "arms" read wares; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this ll th day of October, A. p. 19L 1.

. 4 Henry Van Arsdale, (Seal) Acting Commissioner of Patents

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