US2918967A - Burners for gaseous fuel - Google Patents

Description

Dec. 29, 1959 H. G. HAYS ETAL BURNERS FOR GASEOUS FUEL 4 Sheets-Sheet 1 Filed Sept. 4, 1956 mTN INVENTORS P/c/vard Z. Wemz BY Herberf G. Haj/i M 4! m fl%z TTOPNE Y5 Dec. 29, 1959 H. G. HAYS ETAL BURNERS FOR GASEOUS FUEL 4 Sheets-Sheet 2 Filed Sept. 4, 1956 INVENTORS El a/70rd L War/f2.

Herberf 6'. fiayi ATTORNEYS Dec. 29, 1959 H. G. HAYS ETAL 2,918,967

' BURNEIRS FOR GASEOUS FUEL Filed Sept. 4, 1956 4 Sheets-Sheet 4 IN VENTORS fP/c/mrd L Wemz. Hzrberf G. Hays.

Dec. 29, 1959 H. G. HAYS ET AL BURNERS FOR G ASEOUS FUEL 4 Sheets-Sheet 4 Filed Sept. 4, 1956 5 15 z Y. m ma ww p m/m m VIOL/ M T Mr A mb .ww P Y J B 2,918,967 Patented Dec. 29, 1959 BURNERS FOR GASEUUS FUEL Herbert G. Hays and Richard L. Wentz, Columbus, ()hio, assignors to Armstrong Furnace (10., (Jolurnhus, Ohio, a corporation of Ohio Application September 4, 1956, Serial No. 607,617

3 Claims. (Cl. 158-416) This invention relates to burners for gaseous fuel and particularly to a novel burner construction adapted to produce a more efficient flame and control the path of such flame in a novel manner.

In the production of gas burning furnaces for home heating and the like it has been found to be highly desirable to incorporate a gas burner which will produce a flame which spreads outwardly as it rises from the burner in order to distribute the heating effect over a relatively large area to prevent the development of areas of excessive heat concentration and to more efficiently deliver the products of combustion to the heat exchanger of the furnace.

It is also desirable to effect combustion of the gaseous fuel in as efficient a manner as possible in order to realize a maximum heating effect for the amount of fuel expended.

In general, the burner of the present invention provides the above mentioned desirable advantages by means of extremely simple structure comprising a novel annular burner head which forms a vertically disposed annular passage for the discharge of a mixture of gas and primary air. Such annular fuel-air passage surrounds a relatively large central passage for the upward flow of secondary air at relatively large volumetric flow rates. The secondary air from the central passage serves to feed the inner surface of the wall of flame as it rises upwardly from its annularly shaped origin. The burner head is further provided with an annular guide disposed in the path of the gas-air mixture rising in the annular passage and such guide cooperates with the above mentioned central flow of rising secondary air so as to not only cause the rising wall of flame to extend from its origin in an outwardly spreading pattern, but also serves to maintain such outwardly spreading flame pattern throughout substantially the entire path of propagation of the rising wall of flame. As a result the wall of flame is caused to assume the shape of a frustum of a hollow conic.

As an added advantage of the above described flame pattern, the presence of turbulence along the path of flame development is substantially prevented. It is be lieved that such prevention of turbulence accounts for the very low noise level at which the present burner operates, particularly when the burner is being ignited by the pilot or extinguished as frequently occurs under thermostatically controlled operation of a modern gas furnace.

It is therefore an object of the present invention to provide a novel burner construction of the type described which produces, in a novel manner, an upwardly diverging flame pattern from an annular shaped flame origin.

It is another object of the present invention to provide a novel burner construction of the type described which produces a flame pattern from an annular-type burner which flame pattern achieves greater combustion efficiency as compared to prior types of burners.

It is another object of the present invention to provide a novel burner construction of the type described which incorporates means for preventing the flame from being blown from an annular shaped flame origin and hence from being extinguished by a surge in the outward flow of the gaseous fuel.

it is still another object of the present invention to provide a novel burner construction of the type described which operates at a relatively low noise level, particularly when the burner is being ignited or extinguished.

It is still another object of the present invention to provide a novel burner construction of the type described which develops a flame shape that spreads upwardly and outwardly from a central flow of secondary air, and which burner construction is adapted to vary the angle of inclination of the flame by varying the volumetric flow rate of said central flow of secondary air.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein preferred forms of embodiments of the invention are clearly shown.

in the drawing:

Figure l is a side view, partially in section, of a burner constructed according to the present invention. The section is taken along the line i.l of Figure 1;

Figure 2 is a plan view, partially in section, of the burner of Figure 1. The sections are taken along the lines 2A2A and 2-B-2B of Figure 1;

Figure 3 is a partial view, in broken section, of a typical gas fired furnace for a home and showing the burner of the preceding figures positioned in the combustion chamber of such furnace;

Figure 4 is a partial plan view, partially in section, of a second burner constructed according to the present invention and comprising a second embodiment thereof. The section is taken along the line 44 of Figure 5;

Figure 5 is a side view, partially in section, of the burner construction of Figure 4. The section is taken along the line 55 of Figure 4; and

Figure 6 is a partial side sectional view of the fuel discharge portion of the burner construction of Figures 1 and 2. The section is taken along the line 66 of Figure 1.

Referring in detail to the drawing, Figures 1 and 2 illustrate a gas burner indicated generally at 24 which is constructed according to the present invention and of a type incorporated in the combustion chamber 22 of a furnace 23 in the manner illustrated in Figure 3. Burner 24 includes an intake tube 25 provided with a venturi section 26 which receives gas from intake fitting 27 connected to a source of gaseous fuel, not illustrated. Primary air enters air intake openings 28 and mixes with the gas flow in chamber 29. The air is drawn into chamber 29 due to the drop in pressure of the flow at ven-turi 26.

The air-fuel mixture flows through tube 25 into annular chamber 3-1 formed by inner cylindrical member 32 and outer wall 34 formed by joined casing portions 35 and 36 best seen in Figure 2. Casing portions 35 and 36 form a socket 3'7 for receiving the end of intake tube 25. Flanges 38 and 39 are preferably permanently joined by welding, whereas flanges 4i? are not permanently joined but are provided with aligned holes 41 through which a bolt 42 is extended and a nut 43 is provided on the bolt for drawing flanges 49 together whereby the end of tube 25 is retained in socket 37 by clamp action.

With reference to Figure l, cylindrical inner member 32 is preferably permanently secured to casing portions 35 and 36 by welding together coextensive flanges 45 and 46. A plurality of legs 47, 48, and 49 support the burner head above the underlying surface 50, and an additional leg or bracket 52 is used to support the mixlengths of flow arrows 56 and 58 in Figure 6.

3 ing chamber and venturi section at the other end of the assembly.

With reference to Figures 1 and 6, the upper end of inner cylindrical member 32 includes an outwardly disposed flange 54 and an upwardly disposed flange 53. Outwardly disposed flange 54 includes a surface 55 disposed in the path of the air-gas flow rising in annular chamber 31 and serves to deflect such flow in the manner illustrated by arrows 56 and 58 in Figure 6.

With continued reference to Figures 1 and 6, central secondary air for feeding inner surface 64 of a wall of flame 65 is free to enter a central passage 60 formed by inner cylindrical member 32 since legs 47, 48, and 49 maintain the bottom of the burner head above supporting surface 50. Such central secondary air is drawn inwardly at the space 62 at the periphery of the base of the burner head and thence upwardly in central passage 60 due to the draft created by the rising wall of flames 65. The flow of central secondary air is schematically represented by flow arrows 66.

The outer surface 67 of wall of flame 65 is fed by outer secondary air drawn upwardly exterior of the burner head by the draft created by the flame and the flow of such outer secondary air is schematically represented by arrows 80.

As seen in Figures 1, 2, and 6, the exit for the airgas mixture is provided with an annular band 82 supported by casing portions 35 and 36. As seen in Figure 1 band 82 is formed with outward protrusions 83 which engage the inner surface 85 of wall 34 and maintain the band in spaced relationship therewith to form a restricted passage portion 86. The upper end of easing portions 35 and 36 are flanged outwardly at 87 and cooperate with band 82. to form expanded passage portion 90.

The purpose of restricted passage portion 86 and expanded passage portion 90, formed by band 82 and outwardly flanged portion 87, is to provide a decrease in the velocity of flow of outer strata of the rising air-gas mixture as compared to the velocity. of flow of inner strata of said rising air-gas mixture. This velocity relationship is schematically represented by the relative It will be noted that arrows 56, which represent the expanded decreased velocity flow in expanded passage portion 90, are shorter in length than arrows 58 which represent the higher velocityflow occurring at the strata in annular passage 31 which are inwardly of annular band 82. Due to the decreased velocity of flow of the outer strata leaving expanded passage portion 96 the base of the wall of flame 65 will not be blown away from a lip 92 which forms a base or origin for flame 65. Hence undesired blow-outs are prevented when surges in the flow of the air-fuel mixture occur. It has been found that with the present burner construction the base of the inner surface 64 of flame 65 will ride an outer surface 94 of flange 53 at an annular origin located approximately at 95 in Figure 6.

In operation of the embodiment of Figures 1, 2, and 6, primary air enters opening 28 and mixes in chamber 29 with gas entering such chamber through fitting 27. The air-gas mixture progresses through venturi 26 and tube 25 and flows around the confronting walls of annular chamber 31. With the annular chamber filled a vertical flow is established therein and the air-gas mixture escaping from the exit of annular chamber 31 is ignited by, a pilot, not illustrated, to establish a rising wall of flame 65. Since the escaping fuel is deflected outwardly by surface 55, Figure 6, the longitudinal axes of flames forming flame wall 65 will spread outwardly at the base of such flame wall. A flow of central secondary air, represented by arrows 66, is furnished by central passage 60, and serves to feed the inner surface 64 of the flame wall 65 with ample secondary air to support eflicient non-turbulent combustion along the entire path of propagation of flame Wall 65. Hence it will be understood that deflecting surface 55 cooperates with the supply of central secondary air from passage 60 in forming and continuously maintaining an outwardly spreading nonturbulent flame wall shaped substantially in the form of a frustum of a hollow conic. Such flame form not only serves to spread the heating effect over a relatively large area, but also provides eflicient combustion of fuel and operates at a relatively low noise level.

Reference is next made to Figures 4 and 5 which illustrate a second burner 20-A constructed according to the present invention and comprising a second aspect thereof. All elements of burner 20-A which correspond to identical elements previously described in connection with burner 20 are designated by identical numerals. The structure of burner 20-A (Figures 4 and 5) differs from that of burner 20 in that the former includes outer casing portions 35-A and 36-A which form an outer cylindrical wall 34-A that may include an outwardly flanged portion 87.A at the air-gas outlet. The upper termination of wall 34-A has fitted to its inner surface a corrugated annular band 98 which forms a plurality of relatively small passages 99 disposed in the path of flow of only outer strata of the flow of air-gas mixture rising in an nular passage 31, the inner strata of flow having no such relatively'small passages 99 disposed in their path. With this arrangement the velocity of rise of only the outer strata in passage 31 are subjected to resistance to flow imposed by relatively small passages 99 whereby the velocity of flow of such outer strata, at lip 92-A is decreased relative to the flow velocity of strata inwardly of corrugated band 98. Hence the base of the wall of flame riding lip 92-A will not be blown outwardly by surges in flow of the outwardly flowing air fuel mixture and undesired blow-outs are prevented.

The burner 20-A receives central secondary air from central passage 60, and peripheral or outer secondary air from around the exterior of the casing in the same manner as previously described in connection with burner 20, and such supply of central secondary air cooperates with deflecting surface 55 in forming and maintaining an outwardly spreading non-turbulent wall of flame shaped substantially as the frustum of a conic.

It should be pointed out that in the case of both the burners 20 and 2A the flame control achieved by the present invention is so effective that the angle A of outward spread of an axis of generation 100 of flame wall 65 can readily be varied, relative to the vertical datum axis 101, by merely varying the entrance area for central secondary air. For example, the entrance space 62, Figure 1, can be increased or decreased by increasing the length of legs 47, 48, and 49, or, if desired, the crosssectional area of central passage 60 can be varied in any suitable manner to vary the volumetric flow rate of central secondary air being delivered to inner surface 64 of flame wall 65. Hence it will be understood that the angle A that flame wall 65 forms with the vertical can readily be varied to establish the desired flame configuration for a given application.

- It should be pointed out that legs 47, 48, and 49 may be adjustably secured to the burner, for example to outer cylindrical wall by means of screws or studs and wing nuts extended through vertical slots in the legs. Such adjustable leg arrangement provides a convenient means for adjusting the effective area of the annular opening through which the flow of secondary air travels to the flame and hence is advantageous for burners to be sold as replacement units for various types of older model furnaces since the flame shape and spread can be readily adjusted to be most eflicient for the particular furnace design.

While the forms of embodiments of the present invention as herein disclosed constitute preferred forms, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

We claim:

1. A burner for gaseous fuel comprising an inner cylindrical Wall member, said inner wall member having air inlet means at its bottom peripheral edge thereof for receiving ambient air therein for vertical passage through and out said inner cylindrical wall member, the upper outlet end of said inner wall member having a circular flange portion on the upper end of said inner cylindrical wall member and extending outwardly therefrom and into a substantially horizontal plane, a cylindrical flange portion on the outer periphery of said outwardly extending circular flange portion, and extending upwardly therefrom in a substantially vertical direction, an outer wall member surrounding said inner cylindrical wall member in spaced relationship thereby forming an outer, vertically extending passageway therebetween through which a fuel-air mixture will flow, said inner and outer wall members being peripherally joined to one another at their bottom peripheral edges, the upper free end of said outer wall member terminating below said outwardly extending circular flange portion forming a fuel-air mixture outlet therebetween, a fuel intake opening means secured to said outer wall member adjacent its lower end adapted to communicate with a source of gaseous fuel, annular band means positioned between said outer wall member and said inner wall member, said annular band means having means supporting said annular band to said outer wall member in slightly spaced relationship immediately adjacent the fuel-air mixture outlet end and below the horizontal flange portion of said inner wall 9 member, said annular band means being located closer to said outer wall member than to said inner wall member to form an outer passage and an inner passage at the fuel-air mixture outlet, with said outer passage being of a smaller cross sectional area than said inner passage, thereby producing a fuel-air mixture having a flow velocity differential between the divided portions thereof.

2. A burner in accordance with claim 1, in which the upper peripheral free end of said outer wall member above the point at which the annular band means is supported therewith is flanged outwardly forming a discharge end having a diameter greater than the normal diameter of said outer wall member.

3. A burner in accordance with claim 1, in which the annular band means has its outer surface vertically corrugated with the outer band member in engagement with the inner surface of the outer wall member, forming a plurality of restricted vertical passageways therebetween.

References Cited in the file of this patent UNITED STATES PATENTS 1,158,986 Cronwell Nov. 2, 1915 2,368,646 Dewey Feb. 6, 1945 2,470,880 Zimbelman et a1. May 24, 1949 2,537,542 Norman Jan. 9, 1951 2,588,895 Tavener Mar. 11, 1952 FOREIGN PATENTS 369,981 France Dec. 3, 1906 1,077,026 France Apr. 28, 1954

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