US2046371A - Combustion apparatus - Google Patents

Description

July 7, 1936. H. A. DREFFEIN 2,046,371

COMBUSTION APPARATUS Filed NOV. 9, 1951 2 Sheets-Sheet w j y Patented July 7, 1936 pir B STA piatti coriaUs'rioN arraaa'rus Henry A. Dreffein, Chicago, lll. Application Ncvemlier 9, 1931, Serial No. 573,512

'7 Claims.

This invention relates in general to combustion apparatus and methods, and has more particular reference to a novel burner construction `and method of combustion.

'While I do not Wish to limit my invention to any particular use, it is particularly applicable to furnaces used in various metallurgical processes involving the heat treatment of, for example, metal packs of sheets, bars and the like. The invention includes, among other objects, the provision of a novel method and apparatus whereby a fixed or substantially constant air supply at constant velocity supplements another air supply which is simultaneously variable with a fuel or gas supply to obtain efficient fuel or com bustion mixtures at all operating pressures of the simultaneously variable gas and air supplies; whereby not withstanding the relatively high velocity and pressure of the fuel mixture either a non-luminous or a luminous hazy flamemay be obtained at the will of the operator and the hitherto objectionable cool zone between the l burner andthe flame is eliminated in the case of a luminous flame by a species of pilot light which ignites and maintains the flame at the burner heat outlet; whereby such a luminous hazy flame is caused by innumerablev solid carbonaceous particles produced from the fuel and utilized as heat conveyors and radiators; whereby to produce a luminous flame with sufficient velocity of fuel supply to cause the flame to extend a desired distance from the burner outlet; whereby to provide a method and means for producing such a flame in combination with a furnace of the type r disclosed in my United States Letters Patent No. 1,779,964; and whereby, in general, to provide novel apparatus for carrying out the objects of the invention.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawings, in which similar characters of reference indicate similar parts of the several views.

In the drawings,

Fig. 1 is a cross section through a portion of a novel combustion apparatus embodying the features of my invention;

Fig. 2 is a cross section taken substantially on the line 2-2 of Fig. l; and

Fig. 3 shows in horizontal section a furnace equipped with the novel burner of myinvention.

To accomplish the foregoing objects vI provide a burner I I for a combustion apparatus, diagrammatically illustrated at I2 in Figs. 1 and 2. This Sii burner II has side walls I3 and I4, end walls I5 and I6, a top I 'I and a bottom I8 of suitable re-` fractories, and is so arranged as tosupply heat to the combustion apparatus I2 through an orifice or nozzle I9 carried in the end wall I5. f

The nozzle or orifice I9 cooperates with anv airV .5 supply nozzle 2| carried at the inner end of an air supply main or pipe 22 to provide an injector for entraining or inducing fuel from a fuel chamber 23 defined by the side, end, bottom 'and'top walls of the burner, and mixing the air from the 10 pipe 22 with the fuel for combustion at the nozzle or orice I9. The air supply pipe 22 enters the chamber 23 through the end wall I6 and suitable packing or connections 24.

Any hydro-carbon gas such as natural gas, pro-v 15 ducer gas or a suitable mixture of producergas and natural gas, is supplied to the chambert by means of a supply pipe or main 25 entering the chamber 23 through the wall I5, and suitable packing or connections 28, this pipe 25 extendingv 20 substantially the full length of theffuel chamber wherein it is provided with a plurality of spaced gas jets or orices 2l. Y l i 'Ihe rate of gas and air supplied to the burner I I may be independently controlled'by an air con- 2 5 trol valve 29 and a gas control valve 3i in the pipes 22 and 25. Preferably, however, the rates of air and gas supplied to the burner to produce a combustion mixture at the orifice i9 are 'simul taneously adjustable bya common valve operati` 30 ing device 39 fortan air control valve V29' anda Y gas control valve SI. As will be apparent, the common operating device may Vbe actuated manually or by any suitable automatic actuating means. v In order to avoid improper mixtures of air from the pipe 22 and gas from the chamber 23 due to reduced air pressures and velocities at the nozzle 2I during low heat supply from the burner to the combustion apparatus, and in order toA ,cause the mixing of the air and gas during such conditions in the orifice I9, I employ' a constant or fixed supply of air which is delivered to the burner through a supply pipe 32 concentrically arranged in the supply pipe 22 by a reducer coupling 33', 45 The air supplied from this pipe has sufficient 'pressure and velocity to maintain the injector action with the orifice I9 and to project or extend the flame and gases into the nozzle i9 evenuduring" periods when the burneris delivering a minimum of heat to the combustion apparatus. A valve 34 is provided for controlling this rxed orconstant air supply from the pipe 32. Y `Y Notwithstanding the high pressure and velocity of air delivered by the constant air supplyr'p'ipe 55 32 fromjthe nozzle 2|, Iprovide means for producing a luminous hazy flame at the orices |9, which flame is more rapid toheat and more rapid` VVto cool than non-luminous clear ames, and which Yjets or oricesr21 andY impinging againstra side of the baille. rTherbaflle 35 is` so arranged inrespect of the lside VWall I3 that the gas from the jets`21 are directed first against the baille Yand then permitted to rise slowlyl upwardly abovethe baille,rfollowing generally the surface of the side .As the gas rises in the chamber 23 it will grad-l ually fdi'luse laterally and transversely of the "chamber, from which it may be entrained by the injector action of the nozzles |9 and 2|. An airV f supply pipe or main 35 entersY the burner and communicates with. the chamber 23 through the side Wall |4 and suitable packing and connections Y 31at the opposite side of-the T-shapedV baille 35 from the gas supply pipe 25.k The air supplied by Y Vthe pipe 36 may come from the same source as Y the air supplied by the pipe 22 to which it is connected byV afpipe landY is controlled by aY suiti Y able valveV 38' so that Ywhenfthe valve 38 is open and the common control 3Q is operated to control Vf fthe rateof supply of gas through the pipe 25 Vand air through the pipe 22, the pipe 36 will deliver sufficient Vairfto the chamber 23 to support'` partial combustion ofthe gas from the jets 21 .ignited in Vthe chamber 23 through a Ysuitable aperture o1' Y' opening 39linthe end. wall I6.

vThe air supplied by the pipe Simpinges against the side of the T,shaped baffle 35 ropposite. the side aganstewhich the gas from the jets 21 impinges Yandis retarded in velocity, rising likethe gas from Y i fthe jets generally along the side wall |4and diffusing slowly Witlr the gas above; the T-,shaped baille 35.. This partial combustion` of the gas in the chamber'23produces.innumerable solid productsof partial combustion, such as particles of soot andv carbon Whichrareentrained along with the partially burned' fuel by theV injector action of the nozzles 9 and 2 the flame in the chamber .l 23l serving asa species of pilot 'light or burner to ignite the mixture of the partiallyburned "fuel and the air from the-nozzle '2| Yand to maintain the flame extending from adjacent the nozzle2| intothe nozzle V| 9. By maintaining Vthe flame at the nozzle'l in trhis'manner I eliminate the relatively cool zone which'has heretofore been Acaused insuchV burners between the nozzle and the flame. These products of partial combustion, soot or carbon produced in the chamber 23 bythe slow partialburning ofV any hydro-carbon. gasY in aV defciency of oxygen, arev good absorbers of heat and may, therefore, Vbe employed as. heat conveyors wand radiators. VWhen'thepartially burned fuel,

ladenA with orf containing these soot particles, is mixed with the airY from the nozzle 2| andignited byvthe'ame from the chamber 23; a luminousVU hazy'ame results atthe nozzle 2| and extends," intotheycombustion apparatus. The sooty par-Y Y ticles, having become Vluminous by theheat absorbedfrom the partialcombustion of the fuel in thechamber 23 andithe final Vcombustion in A the'flame projecting from the nozzle 2| serve `as rl conveyors of heat and serve to protect the refracvirtueof Vthe arrangement of the apertures Vand tories. The sootyparticlesfmay siibsequ'ently''bel deposited upon the materials being treated to reduce the tendency in the case of metal sheets of sticking together when such sheets are 'rolled in packs, thus serving to produceV the effect of car,-V bon coating which is frequently employed to avoid such sticking together. Y n

Where desired, the burnerl may be employed as a non-luminous or clear flame burner, by closing or nearly closingthe valve 38, lcontrollinglo the air which supports the partial combustion of thejfuel in the chamber V2 3, and permitting the fuel `from the jets or orifices 21 in the-fuel supply Y u pipe 25 to be diffused by the T-shaped baflle 375 in the chamber'23. Where the burnerv is so used,

the rate of air supply from the pipe 22A and the rate Y of gas supply from the pipe 25 may b e independ'- ently controlled by the valves 29 and 3|. VWhen` so employed the constant or fixed air supply' from the pipe 32v assures the proper delivery of the combustion mixture and burning of the fuel mixture and the. delivery ofv heat from the burner to the *Y combustion apparatus even .v during the periods When a minimum heat isrequired by `thepombustion apparatus Vfrom the burner, or in other 25 Words, during such time as the-.rate of supply of gas fromV the pipe 25and air from the pipe 2211s reduced for a Yminimum heat deliveryby the burnmore burners-VII are employed to supply heat to armetal' pack' heatingfurnace', as illustratedat 4| in Fig; 3because this central jet orconstant air supply- 32Qwi1l provide'sumcientfvelocity 'to Ver. This is particularly important whereV one or fac 1 insure the properfunctioning of restricted chamy bers 43 respectivelyalined with the Ynozzles I9 and I" ,communicating with the material treating cham- 'berj44 of the furnace 4|- through a plurality' of gas apertures 45 in balflewalls 46. Each baille` wall 46v extends from the end of each chamber 43 to a point short of theend wallV |,5 of the burner II', providing a chamber" communicating at one end with the nozzle I9 andY at its opposite end Y with the restricted portion 43, and having an open sile` communicating with'V the'` treatingV chamberk 44. TheV hotgases'and ilameemana'ting fromtg *l the orice I9VV are at Vfirst unconflned Vin the chamber 41 and thereafter by virtue of the velocity of air from theconstant air supply pipel32 proaA p elled into the'restricted chamber 43 for inducing gases through the open'side ofthe chamber 41V 53 from the main or'treating chamber V44 and for subsequently recirculating suchrindu'ced gases intoV and through the restricted Vportion Yor chamber .43 into the treating chamber 44. During this unconfined period of the gasestheyy are permitted to expand and heat the materials in' thevchamber 44 by radiation. y Y v v .y .Y

The velocity ofthe gases carries them through theV relatively unconflned space into the more re'- stricted gas Vchambers 43,`setting up therein a Y "greater pressure than that obtaining in the treat-r ing chamber 44. Y The hot'gasesin therestricted portions 43 flow through the gasapertures 45 into f the chamber 44 at the upper portionfthereof byVv directional bailles 48 andpass across and around the articles being Vtreated in the furnace.

j As'will be understood, the furnace 4| ismerely `illustrative o1' one ftype of 'furnace' to whichV my novel burner is applicableV and as illustrated, is 79` preferably of the 4type' disclosed in my United States Letters'Patent No. 1,779,9647dated October 28,(1930. In such a furnace the material to'be treated may be carried through the heat treating chamber by suitable conveyors 49, on which 7 rate of air supply from the pipe 22 may be reduced sufficiently to provide such a low flame, but the air supply from the pipe 32 has' sufficient pressure and velocity to insure the proper delivery and flow of the flame and gases to and in the furnace.

Thus I have provided a novel burner which may optionally produce either a luminous hazy flame or a non-luminous clear flame and which employs a fixed air supply at a constant pressure, and velocity sufficient to obtain a suitable combustion mixture at the burner outlet and to deliver the heat from the burner to the combustion apparatus associated with the burner even during periods when the rate of fuel supply toy the burner is a minimum. This constant air supply by virtue of its relatively high pressure and velocity, enables me to employ such a burner even when producing a luminous hazy flame in connection with metal heating furnaces of the unrestricted portion type disclosed in Fig. 3, without blowing the flame away from the burner and thereby producing a cool zone between the flame and the burner outlet or nozzle. It will be noted that Where the burner is being employed as a luminous hazy flame burner, the air supply from the pipe 22 and the air supply from the pipe 36 for supporting partial combustion in the chamber 23, as well as the fuel supply from the pipe 25, are controlled together and simultaneously by the common control 30, thereby assuring the proper mixtures of fuel and air for partial combustion in the chamber 23 and for the final combustion of fuel and air at the nozzle 2l, while the constant air supply from the pipe 32 is independently controlled for obtaining efficient combustion mixtures at the nozzle at all operating pressures of the simultaneously variable gases and air supplies.

Having thus described my invention, what I claim as new and desire to secure by United States Letters Patent is:

1. In a furnace, a fuel chamber, means for introducing fuel gas into said chamber, means for introducing air for the partial combustion of said fuel gas in said chamber, a chamber outlet member including an orifice communicating with said chamber, a variable air supply nozzle in said chamber and forming with said orifice an injector for inducing the gas and products of partial combustion from said chamber into said outlet member and for providing therein air for the final combustion of said gas, a constant air supply nozzle in said chamber and forming with said orifice an injector for maintaining the injector action during periods of low heat requirements in the furnace, and means for simultaneously varying the rate of supply of the gas, the air for partial combustion, and the air for final combustion.

2. In a furnace, a fuel chamber, means for introducing fuel gas into said chamber, means for introducing air for the partial combustio-n of said fuel gas in said chamber, and means for removing the products of the partial combustion and the gas from said chamber, comprising a chamber outlet member having an orifice therein co-mmunicating with said chamber, a variable air supply nozzle and a constant air supply nozzle in said chamber and each forming with said orifice an injector for inducing the gas and products of partial combustion from said chamber into said outlet member and for providing the-rein` air for the final combustion of said gas, the injector formed by Vsaid constant and variable air supply nozzles and said orifice being arranged in the flame zone of,said chamber whereby the combustion of the unburned fuel from said chamber and the air'for final combustion of the fuel is maintained.

3. In a furnace, a fuel chamber, means for vintroducing fuel gas into said chamber, means for introducing air for the partial combustion of said fuel gas in said chamber, and means cooperating with the aforesaid means for producing a discharge of the gas and products of partial combustion at a relatively high velocity from said chamber, comprising a chamber outlet member having an orifice therein communcating'with said chamber, a variable air sup-ply member and a constant air supply member in said chamber and each forming with said orifice an injector for removing the gas and products of partial combustion from said chamber through said outlet member and for providing air for the final combustion of said fuel gas, the injector formed by said orifice and each said constant and variable air supply members being arranged in the flame zone of said chamber.

4. In a furnace, a fuel chamber, means for introducing fuel gas into said chamber, means for introducing air for the partial combustion of said fuel gas in said chamber, and means cooperating with the aforesaid means for producing a discharge of the gas and products of partial combustion at a relatively high velocity from said v chamber, comprising a variable air supply memi Vber and a constant air supply member in said chamber and each with a, chamber member forming means for removing the gas and products of partial combustion from said chamber and for providing air for the final combustion of said fuel gas, the last said means extending into the flame zone of said chamber.

5. In a furnace, a fuel chamber, means for introducing fuel gas into said chamber, means for Y introducing air for the partial combustion of said fuel gas in saidV chamber, a variable air supply member and a constant air Ysupply member in said chamber for providing air for the final combustion of said gas, means in said chamber for coacting with said variable and constant air supply members whereby the gas and products of partial combustion from said chamber and the air fo-r final combustion of the Agas are removed from said chamber, and means for simultaneously varying the rate of supply of the gas, the air for partial combustion, and the air for final combustion.

6. In a furnace, a fuel chamber having aheat outlet, means for introducing fuel gas into said chamber, and means for providing a luminous hazy flame outwardly Yadjacent said heat outlet and fed from said chamber by a combustible fuel mixture at a relatively high velo-city, comprising means for introducingl air for the partial combustion of said fuel gas in said chamber, a variable air supply member and a constant air supply member in said chamber for providingrair at a relatively high velocity for the nal combustio-n of said gas, and means in the flame zone of l Y '7.V In a.A furnace, a: fuel chamber having a heat outlet, means for introdung fuelV gas intosaid chamber, Yand means fory providing a. luminous hazy ame outwardly adjacent said heat outlet and fed from said vchamber by afcombustibfle lfuelk mixture at a relatively high velocity, comprising means for introducing air for' the partial cornibustion'of said'fuel gas in said chamberf a'va'- riable air supply member and a constant air sup- 'ply member in said chamber for providing air 2,046,371 Y l K Y at a relatively high velocity `for thecinal.r com- Y bustion of said gas, and means in the I ia'me zone of said chamber forlcoacting with said variable and constant air supply members whereby the ,gapsrand products of partial combustion from said chamber and the air for the nal combustion of thel gas are. projected through said heat outletf* and operable means for controlling said means for introducing air for` thepartial combustion` of said fue] gas, whereby the second said means provides alclea'r flame outwardlyY adjacent said heat outlet and fedvfrom said chamber-by acombustible fuel mixture at a relatively high ve-v locity. n

` HENRYY A.

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