US2428998A - Burner with heated top plate - Google Patents

Description

Oct. 14;v 1947. E. L. SIMPSON BURNER WITH HEATED TOP PLATE Filed Dec. l, 1944 5 Sheets-Sheet 1 BURNER WITH HEATED TOP PLATE Filed Dec. 1; 1944 s sheetssneet 2 Oct. 14, 1947. E. L. s lMPsoN 2,428,998 A BURNER WITH'HEATED TOP PLATE Filed Dec. l, 1944 3 Sheets-Sheet 1 5 Patented. a. 14, 1947 UNITED STATES PATENT OFFICE Earl L. Simpson, Mount Vernon, Ill. Application December 1, 1944, Serial No. 566,124

5 Claims.

1 This invention relates to burners, and with regard to certain more specic features to gas burners for gas cooking stoves, ranges and the r like.

Among the several objects of the invention may be noted the provision of a gas burner employing atmospheric injection of primary air in amounts up to. one hundred per cent; the provision of a vburner of the c'ass described which substantially increases the efficiency of heat transmission to cooking utensils heated by the burner; the provision of a controllable burner of the class described which will operate under all adjustments without danger of either llame extinction or flash-back to the injector; the provision of a burner of this class which with substantiallyno (or aminimum amount of) secondary air burns with a desirable short, hard, horizontal and sheetlike flame which may be placed close to the point of heat application; and the provision of a burner of this class which is simple and economical to construct and maintain. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplied in the structures hereinafter described, and the scope of the application of Ywhich will be indicated in thefollowing claims.

In the accompanying drawings, in which are illustrated several of various possible embodiments of the invention,

Fig. 1 is a top plan view of one form of burner embodying the invention;

Fig. 2i is a vertical section taken on line 2--2 of Fig. 1;

Fig. 3 is a horizontal section taken on `line 3-3 of Fig. 2;

Fig. 4 is an oblique view of the bottom surface of an upper heating plate shown orthographically in Figs. 1 and 2; v

Fig. 5 is a View similar to Fig. 3 showing another form of the invention, parts being broken away forvclarity and the dot-dash line indicating the location of the heating plate;

Fig. 6 is a vertical section taken on line 6--6 of Fig. 5;

of Fig. 8, except that the said heating plate and said dividing header are shown complete and in solid lines;

Fig. 10 is a plan view on the scale of Fig. 'I of a dividing header;

Fig. 11 is a view similar to Fig. 4 but showing a modied form of heating plate; and,

Fig. 12 is an enlarged vertical section taken on line |2--l2 of Fig. 9.

Similar reference characters indicate correspending parts throughout the several views .of the drawings. -f

For gas burners for gas stoves and the like, atmospheric injection of primary air is generali used, as distinguished Afrom injection by mechani` cal compression. This is accomplished byassociating the gas pipe 4such as shown at l in Figs. 1 and 2 with a fuel pipe 3 having a tapered air inlet 5 of the so-called venturi type. Fuel pipe 3 connects with the burner manifold, in this case Agenericaly indexed l. Flow of gas under pressure from the pipe i inspires primary air into the venturi 5 and the resulting combustible air-gas mixture Ilows through the pipe 3 to the manifold 1.

Heretofore it has been common practice to use not over 60% of primary air by injection, relying upon the addition of secondary air at the burner Fig. 7 is a detail plan view on a reduced scale outlets substantially to complete combustion to carbon dioxide (COz). By definition 100% primary air by injection means that an amount of air is drawn into the venturi 5 such that there is obtained substantially complete combustion of the gas to CO2, leaving no carbon monoxide (CO) Anyv percentage less than 100% means that only an aliquot conversion has been made to CO2. To

complete such conversion. secondary air is added to the name outside of Ithe burner.

The reason for the use heretofore of not more than of primary air in a case of atmosphericl injection was thatonly by so restricting the amount of primary air Acould completely con.- trolled performance be obtained, that is, prevention of flash-back upon very low throttling, or'

blowing out of the name under wide open operation. It is understood in this connection that control was effected by a suitable control valve in the gas pipe I. Heretofore flash-back was aggravated when burner ports had relativelylarge areas; and blow-out of the llame was aggravated when the ports had small areas. The former solution to the problem wasV the reduction in the amount of primary air used with a proportionate increase in the amount of secondary air brought into play outside of the burner at the name. The

. 3 present invention solves the problem by allowing the use of as high as 60% to 100% of primary air and shapingthe burner elements and ports in a novel manner.

Heretofore when combustion took place in a flame which employed both primary and secondary air, there were three so-.called mantles: (1) the mantle constituted by the entering combustible mixture; (2) a second mantle constituted by combustion which is incomplete due to a deficiency of primary air; and (3) the third mantle caused by completion of the combustion with secondary air.4 According to the present invention the third mantle is substantially eliminated or at least greatly reduced because of the great in-` crease of the amount of primary air employed. The result is what is called a short, hard flame which may be placed close to the vessel or the like into which the resulting heat is to be received. This closeness is due to yery little free space being required for any secondary air mixing. The result is a greatly increased efficiencyy of heat conduction to the utensil being heated. For example, by means of the present invention the efficiency of heat delivery is raised from the old order of45-50% to something of the order of 68%, where efficiency is defined as the ratio of the heat transmitted to a standard utensil having standard contents as compared to al1 of the heat theoretically available in the gas which is being burned. n

The present invention allows the stated increased use of primary. air with a full range of control and the stated increase in efficiency.

Referring now more particularly to Figs. 1-4, the ordinary Venturi pipe arrangement is shown at said numerals I, 3 and 5. Pipe I includes the ordinary control valve (not shown). Increased primary air (up to 100%) is obtained by' properly adjusting the pipe I with respect to the venturi 5.-

The new burner per se consists of a new manifold 1 which is cruciform in shape with hollow channel-shaped limbs 9, I'I, I3 and I5. Although a four-limbed cruciform shape is shown, other similar shapes may be used, for example three, five, six limbs, etc. The limbs have a common bottom I1 and an open top I9 with a preferably at, machined upper edge 2|. A central pipe is shown at numeral 23 but this has no significance in the first form of the invention. although it is significant in connection with the third form to be described. It will be noted that the limb 9 is ofa larger size (cross section) than the limbs I I, I3 and I5 because al1 of the latter are fed by gas therefrom. I

p Resting upon the edge 2i is a preferably stamped, multi-limbed grid member shown generically at numeral 25. This has a central plate 21 which closes the opening at the upper end of the passage in pipe 23. Along the axes of the .limbs 3, II, I3 and I5 this grid has trunks 29 from which extend end branches 3| and central branches 33. At the juncture between the branches 3i are eyelets which accommodate bolts 35, the latter passing downward through openings in the bottom of the manifold below which they are provided with heads 31. Above the grid 25 the bolts 35 are threaded into threaded openings 38 of a hot plate 39. The latter is composed of a fiat deck portion 4I with a cruciform (multilegged) fiat boss 43 on its under side (Fig. 4). The bottom of the boss 43 is machined flat.

The grid 25 is preferably made of flat thin stock not over about .040 inch thick, which may be punched into the shape described. For exl vgas outlets 45, 41 and 49. Important stantially over the order of .040 inch. Furthermore, the thickness of the boss 43 is not over one quarter of an inch or so. Then by adjusting the injection so that 60% .or more of primary air is injected, a short, hard horizontal fiat flame is obtained from the burner outlet quite close to the bottomI of the integral heat-conducting deck 4I of the hot plate. This flame is of generally cruciform shape covering a large area' closely beneath the hot plate. Since a large amount of primary air is used, complete combustion is obtained without the necessity for providing space for the secondary air and the efciency of heat l openings, despite transmission is considerably increased, as above Y indicated.

It will be observed that the hot plate 39 is an integral part of the manifold assembly and is in intimate association therewith throughout a large area. For this reason, and the fact that the horizontal tongues of flame are quite close thereto, there results the high eiliciency `of heat transmission to any utensil on the hot plate.

The horizontally elongate forms of the burner their vertical thinness, avoid blow-out and flash-back.- Heretofore flash-back could be avoided by using many small, round openings but this made blow-out prevalent. Or, blow-out could be avoided by integrating all of the` desired area into a large round opening but then flash-back was invited. By means of the present construction wherein a very long and narrow jet is employed with excess primary air, located as stated, flash-back and blow-out are avoided under all adjustments and efficiency of heat transmission to the vessel supported upon the hot plate 4| is increased.

In the form of the invention already described, a single grid 25 is used to determine the slots. 'I'he number of grids may be increased. thus increasing the layers of iiame from the manifold. Such an alternative construction is shown in Figs. 5-7. In this'case two grids are indicated in Figs. 5 and 6, interleaved with a cruciform spacing header 5I such as shown in Fig. '7.

'Across the ends of the solid margins 53 are formed eyelets 55 for accommodating the fastening bolts 35. Since the header 5I has a continuous outside margin 53, it forms a divider for allowing upward flow of gas from the manifold 1, and also separates the grids 25 so as to form tiers of narrow horizontal openings. In Figs. 5 and 6 only one header 5I and two grids 25 are shown, but it will be understood that by interleaving an additional number of headers 5I with an additional num-ber of grids 25, the capacity of the burner may be built up as desired. The result will -be the provision of tiers of horizontally projected short, hard iiames, the uppermost one of which is quite close to the hot plate 4I.,

From the above it will be seen that an important feature of thel invention is the use of burner slots of not more than .040 inch in width without blow-oir under any cross slots 6| with lateral outlets B3.

plate than flames heretofore.

'acariens normal ame adjustments, the uppermost slots being closer than heretofore to a hot plate integrally organized as part of the manifold. It is to be understood, however, that the invention is also useful where for one reason oranother it is desired to employ secondary air. For example, iu Figs. 8-12 is shown another form of the invention in which like numerals designatel like parts. In this form the grids 25 and the separating headers are the same as before, except at their centers they areA provided with aligned openings 51 for alignment with pipe 23.y n top of the stack of alternately interleaved grids 25 and header 5| is f placed a solid cruciform header member 56, which is detailed in Fig. This alsohas a center opening 51. This enclosing header 56 takes the place of the bottom of the iiat boss 43 of Fig. 4 in forming a top enclosing wall. The hot plate 39 is then formed as shown in Fig. 8, wherein the heating deck 4| is retained but a boss 59 is used having downwardly open, radial The slots 6| and 63 are preferably milled-in the bottom of the boss 59. The threaded openings 38 for the bolts 35 are retained. `Assembly is as shown in Figs. ,8-12, wherein after alternating the grids with the llame-dividing header 5| the enclosing header 56 is applied; then the hot plate 39 with the passages 6| and l6E! facing downward against said enclosing header 56.

. Operation of this form of the invention is as before, so far as is concerned the ow of gas and primary air. The difference is that secondary air may proceed up through the pipe- 23 and the openings 51 now formed in the grids 25, the separating header 5| and the enclosing header 56. This secondary air nds its way to the passages 6| and 63 to provide thin tongues of secondary air directly underneath the hot plate 39. This typeV of construction becomes more important as the number of layers of grid separators is increased because it may be diiiicult to draw in a. suicient amount of primary air under atmospheric injection to supply with' suiiicient'oxygen all of a greater number of gas outlet ports. 'Ihe additional oxygen is thus supplied by the ports 63. The cruciform header 56 of course separates the mass 4of gas andprimary air flowing from the manifold l from the secondary air flowing through the pipe 23 and passages 6 63.

It will be observed in connection with Figs. 8-12 that the space between the uppermost fuel outlets and the hot plate is not increased substantially, as was the case heretofore, merely for the purpose of properly mixing the secondary air. This is because the'secondary air outlets are ilat, and in any event'less secondary air is required since such a large percentage (over 60%) is obtained as primary air with the gas.

In general, the bottom of the hot plate constitutes one wall of the passages through the manifold; and in the form of the invention shown in Figs. 9-12 it constitutes one part of the secondary air passage. In all cases the topmost horizontal flame is much closer to the hot For example, heretofore the heat transfer surfaces were about three quarters of an inch from the burner outlets. According to the present invention they are much closer, being preferably of the order of one quarter and seldom over one half inch away.

It should be understood that t-he radially limbed shape of the manifold and gas outlet parts (of which cruciform shape is one example) is not limiting; 'I'he important consideration in connection with its shape is that it'shall be such that the attached deck of the hot plate 39 may,

overhangy all vor a large portion of the perimeter and slot-like flame outlets. It is also desirable that the shapebe such that a large perimeter be obtained for maximum length of flame outlet.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description yor shown in the accompanying drawings shall be interpreted flames directly under the portions of the `spanning the spaces between the limbs.

as illustrative and not Iclaim:

l. A gas burner comprising a hollow manifold having at least three radially extending channel-shaped limbs openingupward and having a continuous flat upper edge, spacing means disposed upon said upper edge, said spacing means including thin spacers which are relatively narrow with respect to the length of said edge and which arev longitudinally spacedrelatively far apart thereon, and ahot plate disposed on said spacers, said plate having a substantially at upper surface and being of such peripheral outline as to cover said limbs and to span the segin a limiting sense.

mental spaces between adjacent limbs, thereby providing a plurality of narrow elongate slots between said edge and plate adapted to project wide sheet-like 'flames directly under the portions of the plate spanning the spaces between the limbs.

2. A gas burner comprising a hollow manifold having at least three radially extending channelshaped limbs opening upward and having a continuous fiat upper edge, spacing means disposed upon said upper edge, said spacing means comprising a grid having trunk portions extending longitudinally of said limbs and laterally narrow branches extending laterally from said trunk portions with their ends disposed upon said upper edge, and a hot plate disposed on said grid, said plate having a substantially flat upper surface and being of such peripheral outline as to cover said limbs and to span the segmental spaces between adjacent limbs, thereby providing a plurality. of narrow elongate slots between said edge and said plate adapted to project wider sheet-like plate 3. A gas burner comprising a hollow manifold having at least three radially extending channelshaped limbs opening upward and having a continuous flat upper edge, spacing means disposed upon said upper edge, said spacing means includlng thin spacers which are relatively narrow with respect to the length of said edge `and which are longitudinally spaced relatively far apart thereon, and a, hot plate having a, bosson its underside corresponding in shape to said upper edge and disposed on said spacers, said plate having a substantially at upper surface and being of such peripheral outline as to cover said limbs and to span the segmental spaces between adjacent limbs, thereby providing a plurality of nar- Y the spaces between the limbs.

4. A gas burner comprising a hollow manifold having at least three radially extending channelspanning shaped limbs opening upward and having a continuous ilat upper edge, spacing means kdisposed on said upper edge, said spacing means includ edges above the upper edge of the manifoldl and a hot plate disposed on said spacing means, said plate having a substantially fiat upper surface and being of such peripheral outline as to cover said limbs and to span the segmental spaces between adjacent limbs, thereby providing a plurality of narrow elongate slots between the upper edge of the limbs and the plate adapted to project wide sheet-like flames directly under the portions of the plates spanningl the spaces between the limbs.

5. A gas burner comprising a hollow manifold .a solid wall member of substantially the same shapel as vsaid limbs disposed on said spacing means, a hot plate having a boss on its underside `corresponding in shape to said edge and disposed on said solid wall member, said plate having a substantially fiat upper surface and being of such spaced relatively far apart theregn alternating Y with open separating members having continuous Yhaving at least three radially'extending channelondary air to said passages.

peripheral outline as to span the segmental spaces between adjacent limbs, said boss havingY secondary air' passages therethrough, said manifold, spacing means and wall member having independent openings therethrough for supplying sec- EARL L. SIMPSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,494,444 Sass May 20, 1924 1,720,909 Lang July 16, 1929 1,016,869 Beckfield Feb, 6, 1912 1,844,151 Friedman Feb. 9, 1932 1,397,160 Campbell Nov. 15, 1921 1,303,970 Schwartz May 20, 1919 FOREIGNPATENTS Number Country Date 173,593 CireatV Britain Dec. 30l 1921 V448,482 France Sept. 7, 1912

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