US2615509A - Gas burner having multiple primary air inlets - Google Patents

Description

9 J. A. WHITTINGTON 2,615,509

GAS BURNER HAVING ULTIPLE PRIMARY AIR INLETS Filed an. 59. 1949 I 2 SHEETS-SHEET 1 0 1952 ,1. A. WHITTINGTON 2,615,509

GAS BURNER HAVING MULTIPLE PRIMARY AIR I-NLETS Filed Jan. 29, 1949 2 SI-iEETSSl-!EET 2 Patented Oct. 28, 1952 GAS BURNER HAVING MULTIPLE PRIMARY AIR INLETS James A. Whittington, Evanston, 111., assignor of one-half to Alice P. Whittington, Evanston, 111.

Application January 29, 1949, Serial No. 73,590

1 Claim.

The present invention relates to gas burners, and more particularly to the type in which the fuel gas is projected in the form of a jet or jets coordinate with the supplying of a supporter of combustion, such as air, at such jet or jets, and also further supplying of the supporter of combustion to the mixture of gas and air for enhancing the mixture for burning the same without flash back or the like with various types of fuel gases having a wide range of heat values.

Among the objects of the invention is to provide a novel means for burning different kinds of fuel gas, such as natural gas, manufactured gas, and other kinds, or mixtures thereof having different B. t. 11. values, at normal Operating pres- 1 sures thereof and without any adjustment of any part of the means, or any variation of construction of the means, or of any part of the means,

so that the burner of the present invention is .of universal use, and regardless of the normal operating or below normal operating pressure of the gas used, the proper and desired burning. of the gas will occur without any flash back. When, in the present application, I refer to normal operating pressures and pressures below such normal operating pressures, I mean those pressures recommended by the American Gas Association, set forth in Table 2, Page 3l,'Bulletin .No. 10, of American Gas Association 1940, as

follows:

Assumed Type of Gas Gas Pressure InJHZO Coke Oven 3. Mixed 6.0 Natural 7. 0 Butane 11.0

When employing butane, propane or like gases as the fuel gas, it is not necessary to effect any adjustment of the burner of my present invention, but it is necessary to use a ga injection orifice of a. smaller diameter than that used with other fuel gases such as coke oven gas, natural 2 taken in a plane represented by line 22 in Fig. ,l of the drawings; I I v Fig. 3 is a View similar to that shown in Fig. 2 but of a modified form, and as taken ina plane represented by line 33 in Fig. 4 of the drawlngs; I

Fig. 4 is a view in elevation of a part of the form shown in Fig. 3 of the drawings; 0

Fi 5 is an elevational View of a further alternative form of the invention;

Fig. 6 is a transverse sectional view taken in a plane represented by line 66 in Fig. 5 of the drawings;

Fig 7 is'a part elevational and part sectional view taken in a plane represented byline i in Fig. 8 of the drawings of a further alternative form of invention; and, p

Fig. 8 is a top plan view with a part shown in broken section of the form of invention shown in Fig. '7.

Referring more in detail to the drawings, and first more particularly to the form shown in Figures 1 and 2, the burner comprises an elongated gas chamber 20 of any desired cross-:sec-

.tional form, such assquare as shown in Fig. 2,

and at a suitable point, as at an endof the chamber 20, is connected a suitable gas supply duct or the like 2|. The chamber 20 has an upper wall 22 provided with a plurality. of suitably spaced gas orifices 23. The delivery end portion of the gas supply duct 2| may be suitably fitted or connected to a connector or. like member 24 sealingly fitting in an end portion of the chamber 20. While only one gas duct 2! and plug 24 is shown at an end of the chamberZG, it -is to. be understood that the invention comprehends the providing of a similar duct-and plug means or equivalent means at other points of the chamber 20, such as the other end thereof.

Spacedly above the upper or top wall 22 of the chamber 20 is provided a strip or bar 25 so asto provide between the bar 25 andthe wall 22 an air space or the like 26 open, as at 21, at the sides. (See Fig. 2.) The altitude or width of the air passage is such as to afford flow of air and air will be of sufiicient rate of fiow to draw in additional air through the air space 29 above the member 25.

Spacedly above th member is a similar strip or member 33 thus providing therebetween an air space 29 just above referred to, such space or the like 29 being open or having openings 31 at the sides for'the free entry of air to the space 29. The member is provided with orifices or openings 32 each of which is defined by straight sides extending uniformly throughout the length thereof, and arranged in respective alinement with the corresponding holes or orifices 28 in the member 25 and each of such holes 32 being of greater cross-sectional area than that of the corresponding opening or orifice 23 so that upward flow of the mixture will be of sufficient rate. of flow to draw in additional air by way of the openings 3| and space 29. The altitude or Width of the air passage 3l-29 is such as to afford flow of air to the gas and air mixture streainemerging or jetting from the opening or orifice 28 to quickly mix with the mixture jetting from said opening or orifice. The altitude of the passage 29 is not critical and, hence, may vary within a reasonable range, but it is preferable for the altitude of the air passage 29 to be greater than the altitude of the air passage 26.

Spacedly above the member 30 is a similar strip or member 33 providing therebetween an air space orpassag'e 34, such space or passage having openings or the like at the sides for free entry of air to the space 34. The altitude of the passage or space 34-35 is preferably less than that of the space29-3I but may be greater than or even about that of the altitude of the space 26-21.

The member 33 is provided with holes or opentime 36 each of which is defined by straight sides extending uniformly throughout the length thereof, and arranged in respective alinement with the corresponding holes or orifices 32 in the member 30 and each of such holes 36 is-of greater cross-sectional area than that of the corresponding opening or' orifice 32 so that upward flow of the mixture will be of sufficient rate of flow to d'r'aw in additional air by way of the openings 35 and the space 34. The altitude or width of the air passage 34-35 is such as to afford flow of air't'o the gas and air mixture stream emerging or j'etting'from the opening or orifice 32 to-quickly mix with the mixture jetting from said opening oror'ifice.

I Abovethe member 33 at each opening 36 is a burner head or the like 31 having at its lower enda neck or the like 33 suitably fixed in sealing connection with the top of the strip 33 in circumscribed or encircling relation to opening 36 to establish direct communication between them, and fromthe neck 38-extend upwardly a pair of opposed tapering orinclined side walls 39, 3 9'prov'iding therebetween a tapered or wedge like chamber 40, thesewallshaving along their sides andat'their ends spaced lips or flanges 4 E, 4i and 4 2, 42" so as to provid between said lips or flanges narrow elongated burner slots or orifices 4'3, 43 and 44', and at the lower ends of the walls 39, 39 is provided a sealing member or strip 45. The effective width of the burner slots or orifices 4'3, 43-, and 44, when employed for the burning of manufactured gas is of the order of %4"',,such width being more or less standardized for the various natural and artificial gases as fully set forth by specifications of the American GasAssociation, appearing inthe table on page 1'0, Bulletin of American Gas Association, 1940. The burner or flame orifice 44-43-43 extends along the sides and along the end of the burner nozzle 31 so as to produce a U-shaped fiat flame. The air at or outside such burner slot or orifice 44-43-43 will be in such proportional abundance as to cause combustion at or just beyond such slot or orifice. This is'tiiueregardless of the type of gas used and also regardless of variations in normal operating pressures and pressures below said normal operating pressures. When the pressure is low the aspirating effect at the openings or orifices 23, 28 and 32 will be low and, when the pressure is high the aspirating effect at the openings or orifices 23, 28 and 32 will be high, so that in any case approximately the same proportions of air to gas or to the gas mixture will always be in the same relation. It will be noted that the neck 38 of the burner head 31 has an internal diameter substantially equal to the diameter of thefuppermost hole or opening 36" and greater than the diameter of the opening 3 2. By virtue of this construction air-gas mixture will pass freely and without interruptionor restriction into-theburner head 37 through the'neck 3B. This feature is clearly illustrated in Fig. 1 of'the accompanying drawing. 7

The amount of primary air mixed with the stream of gas as it flows from gas orifice 23 through opening '33 is effected by the resistance to fluid flow through the burner, which resistance is affected by theareaof the flame port 43-43-44. A greater extent of areaof 'fl'a-me port 43-4 3-44 will" permit a greater percentage of'prim'ary' air to be injected by the momentum of the gas stream. Conversely; a-less'erextentof area of the flame port 43-43-44 will permit a smaller percentage of primary air to be injected by the momentum of" the gas stream; the gas input to this burner from gas-orifice 2-3 remaining constant. One square inchof area of flame port 43-43-44 per 20,000 B: t. u.s input per hour at normal gas pressure has been found to give very good results; The ratio offl'ameport area to'B. t. u. input per hour may be varied co'nsiderably depending upon the airgas-'ratio desired; and a-p'ort area of from one to four' times the area of the inlet port of the neck of the burner head has been found to produce results which are entirely satisfactory. The determination of the proper portarea for a given B. t. u. input per hour may be readily calculated in accordance" with existing standards, as outlined, for example,.in Table No. 3, page 65, Bulletin No. 10, of American Gas Association, 1940.

Referring now to -Figs. 3 and-4, a gas chamber 45, corresponding to the gas chamber 20 of the form shown in Figs. 1 and 2, may be used, and it may be of any desired cross-sectional form, as roundas shown, and at spaced points there along are provided hubsor necks-46 in which may be suitably connected orifice nozzle members or elements 4'! provided with a stub 48- threaded' or otherwise fixed to the hub or: neck46, and/having. a chamber 49, at the upper endof which is a gas orifice 50'. Y

To the part 4'! is fitted a tubular member 61 having spaced walls or web members 5!, 52,. 53 and 54 jcorresponding, respectively, to the members or parts 22, 25, 3B and 33 of the form, of the present invention shown in Figs. 1 and 2, particularly in Fig. 2, The member 61 has a hub portion 55 to fit on and to the part 4 1, and the wall, parts 51, 52, 53 and 54'. are provided with openings or orifices 5'6, 51, 58and 59' corresponding, respectively, to the holes or orifices 23, 28, 32 and 36 in the device as shown in Fig. 2. It will be noted that the openings 51, 58, and 58 are each defined by straight sides extending uniformly throughout the length thereof and that the diameters of said openings increase progressively from opening 51 to opening 59. Between said wall parts 5i, 52, 53 and 54 are provided air spaces or passages 60, El and 62 which have air entry parts 63, 64 and 65 provided in the cylindrical wall 66 of the structure. The gas jet orifice comprises the alined orifices or parts 50 and 56 and corresponds to the gas orifice 23 in Fig. 2. The orifices 51, 58 and 59 correspond respectively to the orifices 28, 32 and 36 shown in Fig. 2. At the upper end of tubular member 61, a burner head 31 is attached to the part 58 in the same way as the burner head 31 is attached to the part 33 in Fig. 2. In this form of the present invention, the neck portion of the burner head3'l has an internal diameter substantially equal to the diameter of the uppermost hole or opening 59 and greater than the diameter of the opening 58, this construction permitting the air-gas mixture to pass freely and without interruption or restriction into the burner head 3'! through the neck thereof. This device operates in the same way as the device shown in Figs. 1 and 2.

The thickness of the plate through which the orifices are formed is not critical, and burners of the present invention have been successfully operated with plates which vary in thickness from inch to 3 inch, The sizeof the orifices is not critical, and burners of the present invention have been successfully operated with orifices of inch, inch, and inch in series, and inch, inch, and inch in series, with entirely satisfactory results in each-instance. The spacing or distance between theplates is not critical,

andburners of the present invention have been successfully operated with a distance of .085 inch to .125 inch between the gas orifice and the first plate, a distance of e g inch to inchbetween the first and second plates, and a distance of A3 inch to 5% inch between the second and third plates. The size r dimensions of the gas inlet orifice, the amount of primary air required for eflicient combustion of the gas, and the dimension of the burner port where. combustion takes place, are all well within the knowledge of one skilled in the art to which the present invention relates, and are readily ascertainable from such publications as Research Bulletin No. 13, Fundamentals of Design of Atmospheric Gas Burner Ports, American Gas Association, 1942; Research Bulletin No. 26, Primary Air Injection Characteristics of Atmospheric Gas Burners, American Gas Association Testing Laboratories, 1944; and many other pertinent publications, particularly those of the American Gas Association.

Referring to Figs. and 6, the form of burner device there shown has a cylindrical wall 66 of the type shown in Figs. 3 and 4 and has a gas supply duct 68 corresponding to the gas orifice nozzle and chamber 4'!4849 shown in Fig. 3. said cylindrical wall 66 having air entries 63, 64 and 65, as shown in Fig. 3; and also interior parts (not shown in Fig. 5) corresponding to the interior parts shown in Fig. 3. The final mixture ofgas and air moves to and through a duct 69 and thence to a burner head 10, corresponding to the burner head 3! shown in Figs. 1, 2, 3 and 4 of the drawings.

6 This burner head 16 comprises a mainly cylindrical shell part or wall member ll enclosing a chamber 12, and provided along a side thereof with a pair of elongated lips or flanges l3, l3 defining therebetweenv a narrow elongated burner slot or orifice 14 corresponding to the burner slot or orifice 43, 63, and 44 shown in Fig. 1 of the accompanying drawings. The chamber member or burner head 16 has at its ends walls or wall members 15 and 16, which members are provided with holes l! and.18 for the connection of a duct, such as duct 68, as to the wall member 15, or a closure'plug'or like member 19 fitted in the wall member 16. The duct 69 has an internal diameter greater than the diameter of the hole or opening in the wall or member between air entries 64 and 55 and, hence, the air-gas mixture may pass freely and without interruption or restriction into the burner head 10, and said duct 69 may be connected to either end of the burner head 10, as to either wall member 75.0r 16, or, if desired, a duct 69 may be connected to each of the Wall members 15, 16. The flame will burn at the flame slot or orifice M as in the case of the slot or orifices 43, 43,. and 44 shown in Fig. 1 of the accompanying drawings.

Referring to Figs. 7 and 8, the type of cylindrical wall shown in Figs. 3, 4, and 5 is connected to a chamber member 88 by way of a duct 8| corresponding to the duct 69 shown in Fig. 5,

or the duct means 41-48 shown in Fig. 3, the

ings 82 communicating with a plurality of ducts I 83 leading to a plurality of burner heads 64 corresponding to the burner heads 31 shown in Figs.

1-4 of the accompanying drawings, or the burner head F0 01' the form of the invention shown in Fig." 6 of said drawings. Each burner head 84 has an entry opening 85 and has converging sides or side walls 86 leading to a'burner slotor orifice 81, and the burner head 84 also flares (see Fig. 7); so thatthe burner slot or orifice 81'is long and narrow, as shown inFigs. 7 .and 8, such slot or orifice 8'! corresponding to thetslot or orifice 43, 63, and 34 of the formsof the present invention shown in Figs. 1-4 of the accompanying drawings, or to slot or orifice '35 shown in Figs. 5 and 6 of said drawings.

The operation and use of thes forms are the same as described above in respect to those shown in Figs. 1-4 of the'drawings.

The above referred'to arrangement and the progressively increasing size of the holes or openings from the gas inlet orifice to the burner head, i. e. the holes or openings 28, 32, and 36 (see Fig. 2) and 51, 58 and 59 (see Fig. 3) of the air and gas mixers, constitute important features of the present invention. In the air-gas mixer'shown in Fig. 2, the stream of gas issuing from gas orifice 23 passes upwardly and into the opening 28 of larger diameter than said orifice 23, which results in the creation of an annular zone of low pressure beneath the member 25 and adjacent and surrounding the lower edge of said opening 28, and extending upwardly through the lower portion of said opening, which low pressure zone causes primary air to be sucked or drawn through 7; theair space 26 to mix with the gas with considerable turbulence to produce a thorough and intimate mixture of said primary air and gas as it flows through the hole or opening 28 toward the burner head. When the air-gas 'mixture issuing from the hole or opening 28 passes up wardly and into the opening 32 of larger diameter thansaid hole or opening 28, a second annular zone of low pressure is created beneaththe member 30 and adjacent and surrounding the lower edge of said opening 32 and extending upwardly through the lower portion of said opening, which low pressure zone causes additional primary air to be sucked or drawn through the air space 29 to-mix with the air-gas mixture with considerable turbulence to produce a thorough and intimate mixture of saidadditional primary air and the air-gas mixture as it flows through the hole or opening 32 toward the burner head. When the air-gas mixture issuing from the hole or opening 32 passes upwardly and into the neck, 38 of burner head 31 of larger internal diameter than said: hole or opening 32, a third annular zone of low pressure is created beneath the member 33 and adjacent and surrounding the lower edge of such portion 38, and extending upwardly through the lower portion of said neck, which low pressure zone causes still further primary air to be sucked or drawn through the air space 34 to mix with the air-gas mixture with considerable turbulence to .produce a more thorough and intimate mixture of the additional primary air and the air-gas mixture as it flows into the burner head 37. Due to the fact that the holes or openings are each defined by straight sides extending uniformly throughout the length thereof and that the successive holes or openings increase in diameters from the gas orifice toward the burner head, the air-gas mixture does not proceed in a streamline fiow but proceedsmore in the nature of a column which, due to the progressive increase in the diameters of the straight side holes or openings, results in the creation of the aforementioned zones of low'pressure beneath each of the successive members, which low pressure zones suck or draw into' the gas'stream the-necessary primary air and create the turbulence necessary to insure a thorough and intimate mixture of the air and gas. These features in combination with the burner head having a chamber provided with an elongated port means open to the air and sufiicient in extentto permit the injection of an amount of primary air proper for combustion of the gaseous fluid mass at said elongated port means, enables the burner of the present invention to be used for the burning of diiferent kinds of fuel gas, such as natural gas, manufactured gas, and other kinds or mixtures thereof, having different B. t. u. values at normal operating pressures or pressures belo normal operating pressures, without flash back or blow off, and without adjustment of the burner.

While I have herein described and upon the drawings shown a few embodiments illustrative of the invention it isto be understood that other constructions, arrangements, details, features, and the lik are comprehended by the invention Without departing from the spirit of'the invention.

Having thus disclosed the invention, I claim:

In a burner of the character disclosed and which has a gas supply means having an orifice for the jetting of gas under pressure therefrom, a series of members arranged in parallel spaced relation and having progressively increasing sized orifices of fixed diameters located in alinement with each other and with the first mentioned orifice, each of said orifices in said members being defined by straight sides extending uniformly throughout the length thereof, the member having the smallest sized orifice being nearest said first mentioned orifice, and the spaces between said members being fixed and forming air inlet passages therebetween for affording flow of air through said passages and into the stream of gaseous fluid moving from an orifice to a next orifice of greater diameter, the flow of air-gas mixture from said gas supply orifice to the orifice of largest diameter creating a zone of low pressure beneath each of said members and adjacent and surrounding the lower edge of each Orifice'in said members and serving to draw in primary air through the spaces between said members to mix with the air-gas mixture, and a burner head member communicating with the last of said series of orifices and having'a' neck portion with an internal bore of a diameter at least as great as the diameter of the orifice in the last member of said series to permit the air-gas mixture to pass freely and without restriction through said neck and into theburner head member, said burner head member having a chamber communicating with said neck and provided with an elongated port means open to the air and sumient in extent to control the injection into the air-gas mixture as it passes through the orifices in the series of members of an amount of primary air required to provide a mixture of the proper air-gas ratio for combustion of the air-gas mixture at said elongated port means.

JAMES A. WHITTINGTON.

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

UNITED STATES PATENTS Great Britain Feb. 18, 1935

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