US2002448A

US2002448A - Atmospheric gas burner

Info

Publication number: US2002448A
Application number: US640701A
Authority: US
Inventors: Harry H Dodge
Original assignee: Individual
Current assignee: Individual
Priority date: 1932-11-01
Filing date: 1932-11-01
Publication date: 1935-05-21
Anticipated expiration: 1952-05-21

Description

Mayzl, 1935. .4., H, DDGE l l 2 ,002A48 ATMOSPHERIC GAS vBURNER Filed Nov. 1", 19:52V 3 sheets-sheet 1 H. H. DODGE I ATMOSPHERIC GAS BURNER May 2l, 1935.

Filed NOV. l, A1952 3 Sheets-Sheet 2 `May 2l, 1935. DQDGE 2,002,448v

- y ATMOSPHERIC GAS BURNER Filed Nov. 1, 19:52 4 3 sheets-sheet s Patented May 21.1',

UNITED` STATES PATENT `OPflTICl..

` j 2,002,448 i i Y ATMOSPHERIC GAS BURNER Harryll. Dodge, Williamsport, Pa. Apinication November 1, 1932, seria1No.'640,'z01 11` claims. (ci. 15s- 104) 'l This invention relates to burners and a method of burning gaseous fuel, having for its 'object to provide a structure simple in parts, as Well as a method, which are more efficient in use than 5' those heretofore proposed.

With these and other objects in View the invention resides in the novell details fof construction and combinations of parts constituting the apparatus, as Well as in the novel steps and combinations of steps constituting the method of burning the fuel mixture, all as will be disclosed more. fully hereinafter and be pointed out particularly in the claims.

Referring to the "accompanying drawings forming a part of this specification in which like numerals designate like partsin all the views,-

Fig. 1 is a horizontal plan View of a burner assembly made in accordance with this invention;

Fig. 2 is a vertical sectional view through the burner shown in Figll;

Fig. 3 is a diagrammatic illustration of a dis` tribution of the flexible hose connections of the secondary air supply to the burner;

in the direction of the arrows; l l Fig. 5 is a vertical sectional view t tion of the arrows;

Fig. 'r` is a. vernam sectional detail of one of the burner ports;

hrough the Fig`.'8 is a longitudinal sectional view through` the mixing chamber for the gaseous fuel and air;

Fig. 9 is an end view of the Venturi tube partially illustrated in Fig. 8, taken as on'the line 9-9 thereof and looking in the direction of the Fig. 10 is an end elevational View of thermixing chamber; and

Fig.` l1 is an end elevation of the air control' disc.

This invention contemplates the provision of a burner assembly for gaseous fuel which can be accommodated to either circular or rectangular fire pots of boilers and the like, the difference being in the formation of the burner proper, since the same fuel mixing apparatus or carburetor can be used with either type of burner. Further, the burner of this invention can be either initially in lstalled or it can be used to replace another type of burner or to `replace the grate of a L boiler construction.

n' existent d *to the front plate lof the boiler as previously In the drawings and with particular reference to Figs. 1, 2 and 3,y I represents somewhat diafA grammatically the outer wall of the boilerfor furnace, and 2 the inner wall thereof ,thereby providing a chamber therebetween for the water represented` at 3. Preferably extending across the lower portion of the boiler, and in what would be the ash pit thereof, there isprovidedany suitable support which, in the drawings, is indicated as an I beam 4 and to the upper surface of which is secured, Aas by the bolt 5, the inner. ex tremity of the substantially horizontal mixing tube E which is of Venturi shape, the smaller end or throat -beingoutermost Y The mixing tube is shown in greater detail Fig. 8 from which it will be seen that the. constrictedend is flared circularly outwardly as indicatedat l't,erminating in a somewhat circular flange"r or plate portion 8 provided at suitablej intervals with apertures 9 to receive bolts for securing said plate portion to the boiler. The outwardly ared flanges I8 of a cup-shaped chamber'l2 are secured by bolts II tothe plate portion 8 and said chamber is provided interiorly and exteriorly respectively with central bosses I3 and I4 which are vconcentric with respect to each l other, the outer boss threaded externally and both bosses continuously threaded interiorly to receive a nozzle I5 one Vend of which is tapered as shown and provided with a central aperture I5 through which the gaseous fuel may pass. A lock nut I'I is employed interiorly of the chamber I2 and threaded upon the nozzle I5 against the end of the inner boss I3 `to secure said nozzle in adjusted position as will be understood.

It is to be particularly observedfrom Fig. 8 that, while the nozzle may be adjusted longitudinally with respect to the axis of the mixing tube 6, the flared portion 1 of said tube is of such radius of curvature that the gas may freely leave said nozzle through the orifice lbefore entering the smallest diameter or throat of the Venturi` shaped mixing tube. 'I'he positions of the nozzle, however, and the curvature of the curved portion of said tube are such that the gas, in leaving the nozzle and striking the curved surface of the portion 1, will never be deflected from said sur'` face in a direction retrograde ofthe general directional flow of gaseous fuel to the burner; in other words any and all gaseous fuel afterleaving the nozzle will flow to and into the throat of the Venturi mixing tube.

The chamber I2, and the outer end ofthe mixing tube 6 are adapted to be supported by bolts chamber I2, there is provided an adjustable disc described, and in this respect it should be stated that the contacting surfaces of the flanged portions 8 and IIB are smoothly finished and/or provided with packing to make a substantially leak proof joint therebetween, Also it should be observed from Fig. 10 that the flange portions I0 of the chamber are not continuous, the construction being such as to provide an angular recess I8 to receive the heads of the bolts passing through the holes S for securing the mixing tube to the front plate of the boiler. By this construction the chamber I2 is secured to the mixing tube independently of the support of the latter by the boiler plate, whereby the chamber may be disconnected for nozzle adjustment'or cleaning without disturbing the rest of the burner assemblage. Therefore it will be understood that the chamber I2 is exterior of the boiler, and consequently is adapted for ready connection to a pipe I9 (see Fig. 4) threaded into the external boss I4 for conveying the gaseous fuel from any source to the nozzle I 5 under any desired and/ or regulated pressure.

Y The outermost wall of the chamber I2 is provided with a plurality of openings 2D which are grouped about the bosses I3 and I4, said openings for admitting air therethrough to mix with the gaseous fuel in said chamber and mixing tube 6 constituting the carburetor for the burner'. In order to control the amount of air entering the 2 I, threaded onto the exterior of the outer boss I4 of said chamber, a lock nut 22 being provided to set the disc in its adjusted position. Therefore it will be understood that air from the furnace room will pass in the direction of the longer a1'- rows through the space between the disc 2| and said chamber, thence through the openings 20 into said chamber, past the nozzle I5 to mix with the gaseous fuel and pass through the tube 6 to the burner.

The gaseous fuel will be under a slight pressure in order to insure flow, and this flow from the end of the nozzle will cause the intake of air into the chamber I2. Also, because of the restricted diameter or throat of the mixingtube 6 being adjacent the nozzle, lthe gaseous fuel and air will be thoroughly mixed by the time the combined gas and air will reach the burner. However, it is important to observe that the mixing tube increases in internal diameter in the direction toward the burner, and this is so proportioned that, by the time the carbureted mixture reaches the burner ports, there will be substantially no pressure. As a result of continued experiments it has been definitely ascertained that, regardless of the initial pressure on the gas flow as it leaves the nozzle, the pressure at the burner ports can be made to be less than 1/100 inch of water, wherefore the burner of this invention is substantially atmospheric.

The opposite or innermost end of the mixing tube 6 is provided with a transverse bend, the extreme end terminating in a portion having an external reduced diameter yto provide an annular shoulder shown at 25 which, when the tube is properly installed, lies in a horizontal plane, said shoulder serving as a seat for the central downwardly extending boss 26 of a cruciform -or branched hollow spider generally indicated by the interior cavity of the spider which in turn communicates through an opening 30 with the passage of the mixing tube G, the passage 3i] being centrally disposed in the spider and concentrically formed in the boss 26. Each arm such as 3i of the cruciform spider is provided in its upper surface with two sets of tapped holes to receive bolts such as 32 for securing a burner section to said arm. The purpose of these two sets of tapped holes is to permit the burner section to be mounted on thespider in one of two positions. In other words the burner section, generally indicated by the numeral 36, is thus permitted a radial adjustment in the boiler whereby, with a spacing of say one inch between the two sets of holes, the same spider may be used with the same burner sections to accommodate boilers differing in diameter by approximately two inches. The two possible positions of a burner section are clearly indicated in Fig. l by solid and dotted line representation.

Each burner section is preferably a hollow casting and comprises a chamber of substantial-y ly T formation, the head of the T being arcuately formed as shown, the arm of the T being adapted to assume a radial position with respect to the boiler and spider. The inner extremity of the arm of the T is curved downwardly as indicated at 33 terminating in an elliptical opening 34 adapted to flt over the opening 29 in the spider, the major axis of the ellipse extending in the direction of the arm of the T to permit of the radial adjustment of the burner section with complete registration of the o-

penings

29 and 34.

'I'he arcuate portion of the burner section is of an extent to approximately lit one fourth of the boiler when a spider with four arms is used, but it will be understood that spiders with a greater or lesser number of arms may be employed in which case the arcuate extent of each burner section will be respectively decreased or increased so that when all burner sections are in place, there will be substantially a continuous circular burner head within the boiler.

In the upper surface of the arcuate portion of each burner section there is provided a plurality of spaced upwardly extending ports one of which is shown in detail in Fig. '7. These ports are substantially tubular vertical passages 35, each of a length suiiicient to prevent the temperature of the flame, formed at the end of the port, from being conducted through the metal of the ports to the gaseous mixture within the burner section, as a result of which said mixture is kept at the lowest temperature possible. In other words, the passages 35 are made sufficiently long to prevent the temperature of the flame causingan ignition of the gaseous mixture within the chamber which would result in a flash back. Also by this construction concussion of ignition is eliminated.

From what has been previously said it will now be understood that the gas entering the chamber I2 under pressure, mixes with air and this mixture enters the throat of the Venturi or mixing tube 6 but, because said tube increases in diameter in a direction away from the mixing chamber l2 and because of the total volumetric capacity of the cavities of the spider 2l and the chambers of the burner sections, the mixture may expand in the spaces in these chambers, and this expansion reduces the pressure whereby, when the mixture passes from the ports 35 of said sections it is under practically no pressure, or a pressure no greater than 1/ 100 inch of water. In other words, and as a concrete example,

according to the construction shown'in Fig. 2 the internal diameter of the Venturi throat is inch, the diameter of the delivery end of the tube 6 is 11/2 inches, the diameter of each ofthe passages 29 of the spider is 1% inches, and the diameterof each of theburner ports 35 is ,je inch; Therefore, the respective areas are, in square inches, 0,60 at the Venturi throat,1.77 at the -discharge of the tube 6, 2.41 at each of the spider passages 29, and.3.30 at the ports of each burner section 36, wherefore there is aV progressive expansion of the fuel mixture per-V mitted from its passage through 0.60 square inch at the Venturi throat to its passage through a total of 13.20 square inches at the burner ports. According to the modification shown in Fig. the diameter of each of the 96 `burner ports Yis 1A; `inch wherefore the corresponding progressive expansionof the fuel mixtureperunderside thereof there is formed a-downwardly mitted is from its passage through 0.60 square inch to its passage through a total of 4.71 square inches since the dimensions of the AVenturi tube are approximately the same as those given above with reference to the construction shown in Fig.

' 2. Hence it follows that the fuel mixture is exhausted through at least two-and-one-half times the area of the delivery end of the tube 6. Since the noise incident to an ignited burner is occasioned by the pressureof the combustible mixture through the burner ports, it will be readily seenthat by this construction there is eliminated noise of combustion which is so common in heretofore known types of gaseous fuel burners. Consequently the most important features of `this invention are directed to the fact that the depth ofthe burner ports 35 coupled with the chamber areas of the Venturi pipe 6, spider 21 and burner sections, all create a definite relationship in conjunctionwith the diameter of the burner ports, to make it impossible for flash back to occur, and to establish a burner which is absolutely noiseless not only during the ignition period, but also throughout the burning period.

`A secondary air supply is provided for this burner. In other words, for the burner section 36 there is a curved box indicatedy at 40 having an open top, the curvature of said box being concentric with the burner section, said box being attached to the underside of said section in any suitable manner as by one or more bolts 4|. The bottom wall of the box is apertured to connect with a exible metallic hose 42 the end of which passes through the wall l of the boiler, as a result of which air from the furnace room is free to pass through said hose into said box and escape from the latter upwardly around the outermost curved wall of the burner section. There is provided sufficient space between said burner section and the water jacket of the boiler for this secondary air supply. There is a similar Secondary air supply for each of the other burner sections, and from Figs. 1, 2 and 3 it will be understood that the

hoses

42, 43, 44 and 45 communicate respectively with the

air boxes

40, 46, 41 and 48 associated respectively with the

burner sections

36, 31, 38 and 39, a disposition of the said hoses being diagrammatically illustrated in Fig. 3. It isrpreferable to have an independent secondary air supply for each burner section but it will be appreciated that a single box could be employed for all of said sections, and further it is possible that, when a plurality of boxes are used, they could be connected to a single secondary fair` deliverymai'n. However, by having separateconduits practically the same amount of air can be supplied to each burner section. The particular disposition *of these conduits Shown in Fig. 3 is 'only by way of example, since obviously each secondary air supply box could be 3 connected` to the atmosphere outside the boiler in anyymanner foundimost suitable to the particular installation.`

Figs. 4, 5 and 6 are specific to a modified form of burner section and secondary air supply, which maybe found more suitable to boilers of rectangularV formation. The mixing chamber l2 and-Venturi tube Gheretofore described are likewise used in this assemblage. `The burner sections, however, are;hollowrectangularV castings such as shown at 50, providedin their upper wall portion with a greatplurality of ports 5I. i f i .i Centrally of the burner'section and on the extendingboss 52.sirnilar tothe boss 26 of the spider illustrated inFigs. 1 and 2, the boss 52 having aiconcentric passage leading `to the "interior'cavity` of the burner section and said boss adapted to tupon the shoulder4 25 of the VenturitubeS.y The burner sections 50'can be made in various dimensions in orderto best t the interior of the boiler but it will be understood that a plurality of such burner sections will be requiredin each boiler, and therefore it is contemplated having a Venturi tube 6 for each burner section, said tubessupported at their outer ends bythe front wall Ix of the boiler. Because the burner sections maybe relatively closely spaced as shown in Fig. 4 it is preferred to cut olf the side portions of the anges 8 ofthe Venturi tube as indicated at 53 in Fig. 9. so that the. Venturi tubes may be correspondingly closely spaced.

The secondary air supply to the rectangular burnerv sections vshown in Figs. 4 and 5 `consists of a box conduit54 disposed between each two` adjacent burner sections, said conduit extending through the rear plate 55 of the boiler with a completely open outer end 56. AThe upper wall of this conduit is provided with a rectangularopening 51V intermediate the adjacent burner sections so that air from said conduit is permitted only to travelI upwardly therefrom between and over the sides of said sections. The end of the conduit opposite the open end 56 is closed. The conduits 54 may be supported within the boiler in any suitable manner, there being illustrated in Fig. 5 an I beam 58 for this purpose, and the innermost end of each Venturi tube 6 may likewise be supported thereon through the instrumentality of a spacing tube 59 having passed therethrough a bolt 60 all as will be readily understood from the drawings.

It is obvious that those skilled in the art may vary the details of construction as well as arrangements of parts without departing from the spirit of the invention, and therefore it is not desired to be limited to the foregoing except as may be required by the claims.

What is claimed is:-

1. In combination a burner; a mixing tube connected to said burner; a chamber associated with the outer end of said tube; an adjustable airintake for said chamber; and a fuel conduit entering said chamber in coaxial alignment with said tube, the inner end of said conduit terminating in a nozzle adjustable toward and away from the tube entrance, said adjustment made from within said chamber only.

2. In combination a burner; a mixingtube connected to said burner; a chamber associated With the outer end of said tube,'said chamber closed except for air-intake ports; and a fuel conduit entering said chamber in coaxial alignment With said tube, the inner end of said conduit terminating in a tubular nozzle having a tapered outlet, said nozzle adjustable toward and away from the tube entrance, said adjustment made from Within said chamber only.

3. In combination a burner; a mixing tube connected to .said burner; a chamber associated with the outer end of said tube, the Wall of said chamber opposite the tube end having an internal and an external-boss, both bosses in coaxial alignment with said tube and provided With a threaded bore, the external boss receiving therein a fuel conduit; and a nozzle threaded into said internal boss, said nozzle having a tapered outlet adjustable toward and away from said tube end, said adjustment made from Within said chamber only.

4. In a boiler construction the combination of a burner; a mixing'tube leading from said burner to av point outside said boiler; a chamber bolted to the outer end of said tube forready detachment therefrom; and a nozzle disposed completely within saidchamber and connected to a source of fuel medium; said nozzle adjustable entirely from Within said chamber.

5. In a boiler construction the combination of a burner; a mixing tube leading from said burner to a point outside said boiler; a cup-shaped chamber provided with outwardly directed edge flanges bolted to the flared outer end of said tube for ready detachment therefrom; and a nozzle disposedl within said chamber in coaxial alignment With said tube, said nozzle connected to a source of fuel medium and adjustable toward and away from said tube entirely from Within said chamber.

6. In a burner construction the combination of a spider of cruciform shape constituting an expansion chamber for receiving fuel; a conduit for supplying fuel to said spider,-said conduit deliveringthe fuel to the under central portion of the spider; and a plurality of burner chambers one for each branch of the spider, said cham'- bers being of T shape With arcuately formed heads and with arms radially adjustable upon the upper surfaces of the branches of said spider, each burner chamber provided with ports for exhausting the fuel, whereby the complete burner is capable of being adjustably tted to circular fire pots of different diameters.

'7. In a burner construction the combination of a spider for receiving fuel; a conduit for supplying fuel tol said spider, said conduit delivering the fuel through the bottom Wall of the spider; and a plurality of yburner chambers one for each branch of the spider, said chambers having arms radially adjustable upon the upper surfaces of the branches of said spider and adapted to receive the fuel therefrom, each burner chamber provided with ports for exhausting the fuel, whereby lthe complete burner is capable of being adjustably fitted to iire pots of different dimensions.

8. For a fuel burner, a spider constituting an expansion chamber for receiving fuel, the inlet for the fuel being disposed in the bottom wall of the spider, the outlet for the fuel being through the upper Wall of each branch of the spider, and means in each branch arranged in plural sets for securing a burner head in radial adjustment With respect to the spider.

9. For a fuel burner, a spider constituting an expansion chamber for receiving fuel, the inlet for the fuel being centrally disposed in the bottom Wall of the' spider, the outlet for the fuel being through the outer portion of the upper wall of each branch of the spider, and means in each branch arranged in plural sets for securing a burner head in radial adjustment with respect to the spider.

10. For a fuel burner, a spider constituting an expansion chamber for receiving fuel, the inlet for the fuel being disposed in the bottom Wall of the spider, the outlet for the fuel being through the upper Wall of each branch of the spider, and threaded connections associated with each branch and arranged in plural sets for securing a burner head in radial adjustment with respect to the spider.

ll. For a fuel burner, a spiderconstituting an expansion chamber and adapted to receive fuel, said spider provided with an outlet in the upper Wall of each branch thereof for passing the fuel to a burner head, and means in each branch a1'- ranged in plural sets for securing the burner head in radial adjustment with respect to the spider.

HARRY H. DODGE.