US1503968A - Gas burner or torch - Google Patents

Description

Aug.

P. F. WILLIS GAS BURNER 0R TORCH Filed June 23, 1919 @@WEJQQZZ CII Patented Ang. 5, 1924.

iran sr TESl PRIOR n. WILLIS,` "oF sT.` LoUIsMIssoURr."

GAS n-IBU'RNER i 0R TORCH.

Application' lled .Tune 23,

To all fui/0m` t may concern;

Beit known thatI, Pinon F. citizen;V of `the United States, residingwin the city of St.-Louis andState of` Missouri, have invented a new and useful' Improvement in Gas Burners or Torches, of which the. following is a specification 4This invention relates vto blow-pipes; welding torches, cutting torches, and, infact, any and `all instruments or toolsiwliich "are usedsv to` combineyand` `burn `a `mixture of oxygen and a combustible-gas: Ithas for4 its principalfobject tolpreventithe occurs rence of flashebacks or lback-liresand `at the same time sec'urethe best-or most desir-1 able normal mixturey 'of` the:` gases, from anV eihcient voperative f and f economical:- Estandfpoint, lin blow-pipes, torchesY and appliancesy of the character above pointed out, `andmore particularly iny oxyacety'lene welding: and cutting `torches or burners which use acetf ylene asithe combustible iand` oxygen as the supporter of combustion, andin which latter devices the gases arel delivered througlifsep-` arate channels or conduits toa mixingchani-4 ber from which the commingled gases flow toxthe `tip of the nozzlefand are` ignited at the orifice thereof.` So far as I am aware,zthere has:` never beeiifconstructed a torcli'or toolfwhiclifunder certain conditions hereinafter stated, `is not subject to the phenomenon',known as a flaslr back or back-nre, while at the `Sametime VViLLis, a

maintaining a ineutralfl flame underfabnor nia-l conditions. I f

Ordinarily, the term flash-back or back-1 lire` means the burning .offtlie cominingled gases `in the mixing chamber; but, under` ex-H` treme conditions the burning'may penetratethehandle of the torch, the hose, or even the regulators. Obviously, this is objectionable, for when the same occurs, thetorch 'is `unworkable and it is necessary to shutoff :at least one of the gases and usually both of them and then re-light `the torch.'

Commercial. oxygen is usuallyfurnished compressed in tanksV and it canbe obtained' of a purity ranging from abouti-96% to as high as 99%. Vhen absolutely purer itrlias a specificgravity'of\l.l05, assuming air to` be` unity or-one. If theoxygen is produced by the electrolyticdecomposition of water,

the vimpurity. will be hydrogen, the liglitestf of gases. If the loxygen is made bythediquid air process, the impurity will benitro-f gen, a gas which is slightly lighterithan air.`

i919. semi No'. snai-a9.

ltffollows from the above that'the introduction of either hydrogen or nitrogen vto commercial oxygen would reduce its specific gravity so that itwould approach moreclosei the weightof air.

Commercial acetylene `is obtained either from a generator making and deliveringthe gas ata pressure not greater than fifteen pounds, `or from so-called safety; tanks in wliicli'the acetylene has been dissolved by means of acetone underfan-` initial pressure of. about two hundred Viifty pounds, but reduced Aby means of regulators to the pressu-re requirediloy thehurner in use. The

specific gravity of chemically pure acetylene, is .91, assuming air to be unity.

Acetylene used commercially for welding, if taken froma generatonwill carry, held in suspension, a certain amount of water vapor. This amount ofiwatervvapor will vary considerably, dependingupon the rate' of generation, weather conditions,` etc. On the other hand, if thegas is taken from a compressed or so-called safety tank, `it will carry, held in suspension, a certain 'amount of the solvent called acetone. The introduction of water vapor or acetone, as the case may be, will materially1 increase the specificV gravity ofthe gas. If theacetylene or the oxygen used commerciallyapproach chemi cal purity, attention should 'begiven `to the differences inspeciiic gravity and accurate allowances made either in the pressureunder which the gases operate orin the' sizes of the openings through which thegases" pass into the mixing chamber. lthaslong been known that a mixturefof acetylene and oxygen, whenlighted, may travel atV a rate of three hundred Athirty feet per second, and it must, therefore, be obvious gases, when lighted, should be under a pressure suflicient toinsure the mixture escaping from the nozzle or tip of the torch at this speed at least.

It has also long beenV known that if a combustible isenriched with air or oxygen beyond the proper amount it will flashback or back-fire and ifthe amount of air or oxygen is sufficiently decreased it is practically `impossible to create a flash` that the two lili l than the oxygen.

completely consume one volume of acet flene. Theoretically, one and one-half volumes of oxygen can be taken from the-atmosphere and the other one volume from the oxygen supply to the mixing chamber.

Now, it has been observed by me, and undoubtedly by others, that a strongly carbonizing flame (that is, one having too much acetylene, or, putting it the other way around, not enough oxygen), if operating under sul'licient pressure, is free from flashbacks.77

It would naturally suggest itself that, if the prevention of flash-backs was the one and only desideratum, the acetylene ports into the mixing chamber should be of such size as to permit a higher pressure In that case, there would at no time be an excess of oxygen, but just as surely there would be a surplus of acetylene as long as the exit of the nozzle was partially closed or the free flow of the gases therefrom interrupted, and this condition might continue indefinitely.

An excess of acetylenev in the flame will be lacking in heat besides depositing carbon in the metal, thereby making it hard and brittle. 0n the other hand, an excess of oxygen will oxidize or burn the metal. Therefore, unless the mixing chamber, the exit of the nozzle, and the various openings into the mixing chamber are so arranged and proportioned that, under proper pressures, the mixed gases will emerge from the nozzle so as to produce a neutral flame, the torch will be valueless, regardless as to its liability to back-lire 'or not.

It is understood that there are two things which practically control the amount or volume of gas passing through an opening and they are the size of the opening and the pressure. If a certain volume of'acetylene travelling at a certain speed is required for a particular size tip, having determined upon the size of the opening, it is an easyy matter to obtain the necessary pressure to produce the speed. If a higher pressure should be desirable, and the volume of gas is to remain constant, the size of the opening is decreased, whereas, of course, if a lower pressure is wanted the opening is enlarged.

If the oxygen entering the ordinary mixingy chamber is under a pressure higher than the acetylene, and the nozzle of thetorch becomes momentarily partially obstructed by flying particles or by touching the metal being treated, or from other causes, it would appear that the oxygen flowing under the higherpressure exerts itself more forcibly, with the result that the gases in the mixing chamber contain a greater amount of oxygen than of acetylene. Where the pressure on the oxygen and the acetylene is the same, this condition still exists, although not to the same extent, probably becausethe oxygen, in spite of impurities in the acetylene, is still the heavier and predominates by reason of this fact, with the result that there is in the mixing chamber an ideal mixture for a flash-back or back-lire and that is what usually occurs. f

Now, in carrying out my invention,'I provide means whereby the oxygen, for a limited space of time, will not force itself through the zone of mixed gases and predominate. This consists partly inA constructing the openings for the acetylene and the oxygen so that they will operate under practically the same pressures. By this I mean that it is preferable to have the pressures of the two gases substantially equal and in that way obtain a purely mechanical, balanced mixture, free from injector or ejector principle. However, a very slight excess of pressure on the acetylene or the oxygen would not materially alter the conditions.

In the accompanying drawing are illustrated two practical adaptations of the invention to Oxy-acetylene welding torches, theV one being embodied in a tip construction and the-other in a handle construction, but, as hereinbefore stated, the invention may be utilized in a wide variety of forms, such as those in which theV mixture is effected within the tip, within the handle, or in frontor behind the handle, or in the head of the torch rather than inthe tip, and in torches or burners utilizing combustibles other'than acetylene.

Figure 1 of the drawing shows a preferred structure of torch head and detach'able tip in` longitudinal section;

Figure 2 is a view of a modification ofthe tip detached; and v *i Figure 3 is a view, partly in elevation and partly-in section, of the torch in which the mixture is eected in the handle.

Referring now more particularly to Figure l of the drawing, the numeral l designates the head of an Oxy-acetylene welding torch having an oxygen supply passage 2 and an acetylene passage 3 therein, and having attached thereto the conducting pipes 4 and 5, which respeetively communicate with said passages 2 and 3, and are attached, in practice, to the usual handle (not shown) at their outer ends, which latter is, ordinarily, obviously provided with suitable gasV passages and cut-oftl valves and has the usual hose connections with the respective sources of gas supply. f v

The head l has a bore 6 therethrough for the reception of the shank portion 7 of a nozzle member or tip 8. The nozzle or tip, as shown, has a tapered shoulder or seating portion 9 at the root of the shank portion 7 which ,ts a kcorrespondingly tapered or ared seat 10 at the adjacent end of the bore 6 of the head 1, while the end portion of i isc cwA

the t shank lis screw-threaded., Jas. at t11j, toen-j ter ,a :screw-threaded axial socket.- 12 linz-a closed plug4 13, which latter is tapered, .as` at 14, toffita correspondingly aredseat 15 inthe adjacent `end lof the-bore 6.,.`

Thenozzle or tip l8 has an axialtbore 16',f the upper portion of whichl constitutes the mixing` chamber for the .oxygen and acetylene. A port 17 i inthe nozzleorztipriopens at itslinner endinto `thebore ..116 and, at'its` outer end through-the tapered seatviportion or shoulder 9 at ,a pointrto registeravith an` annular groove 18 providedl in` the ,flared i seat portion-.10 in the bore 6 ofthe head1,

and with lwhich groove the acetylene passage 3 communicates` i The oxygen .passage 2 communicates with the'bore ofthe head 1 atapointtbetween` the flared end portions `10 and ll thereof,I and the shank portion 7 of the nozzleoritilzyv being of a diameterlessthan that` of the :bore: 6 an annular receiving,chamber 19-xis afforded for the oxygen, landbetween `which chamber. and the bore `16.` of the vnozzle or tip communication ishad through lthe-Jort 20 above or behind they acetylene `porti 1l. f

By the construotionaabove*described, the nozzle or tip is readily attached to and `detached fromithe Vhead 1, and at the same time absolute yseals are providedto prevent the escape of the gases-to theatmosphere-as well as to prevent the commingling `of the two `gases before they enter the ports `17 and 2O respectively.

As shown in Figure; 1, the bore 16. of the nozzleor tip Aextendsii'entirely therethrough and is closed by the plugl, thereby constituting Aa relief` 'chamber 21 above vorbehind the oxygenl inlet.

It has been found that when the torch is operatingnormally,there is produced a partial vacuum in the chamber 21, as compared with the pressure in the remainder of the bore 1G ahead of the oxygen inlet. 'The inflowing oxygen into the nozzle or tip, by reason of its speed, tends to draw or suck o-ut any gas that may have accumulated in this relief chamber 21. Should the orifice of the nozzle or tip become partially obstructed, the acetylene port being ahead or in front of the oxygen port and the pressures of the two gases being substantially the same, the tendency is to slow up the incoming oxygen and divert it up into the relief chamber 21 above or behind the oxygen inlet, with the result that the mixture of the gases in the mixing chamber, for a limited space of time, continues in the same proportions and the flame remains neutral although of a. capacity less than that -of the llame obtained before the outlet of the nozzle or tip became restricted. In other words, the flame is still of the same character, but only of a capacity equivalent to that of asmaller sized nozzle or tip.

Ifjtheiobstruction at the orifice of the nozzle oritip-remains the-baclr-fire may then occur, 1 butgbefore; this happens the .operator has had ample .warning by an increased hissing i, and sputteringthat. the conditions underwhich the .torch @is working are not adapted` togood welding.;-

In :most cases,l if the operator lifts the torch from the. work as soon` as he is aware of thefabnormal conditions, which are readily observed `by, thechangein the capacity of the.iameand,itsl action as above set forth, the .obstruction may disappear i of itselfor be disengagedor discharged from the nozzle-.or tip bythe manual, manipulationoftheioperator, whereupon the original flame is again brought aboutwitliout necessitatingtheyshutting.off of either of the gasesgand re-lightling theitorch as is almost invariably. consequent upon the :happening of such abnormal conditions in theoperatonfof-.the ordinary torches or burners of the character as heretofore constructed.

In Figure 2 of the drawing, `a modificationi of the `nozzle member ortip is illustrated, fin which the relief chamber 21 is counterbored .to a diameter `greater than that of :the boieproper 16` into which the two f gases aree normally discharged and mixed; andthis reliefl chamber is closed at `theouter end by a `plug 22 fitted tightly therein. ln this modification, also, an annular-groovel 18l is provided in the tapered shoulder or seating portion 9 to talre the placeof-or cooperate with the `groove 18 which may or may not be iprovided in the head `l as shownfiniiFigure `1, as maybe desired.;

A further modification is shown in `Figure 3, Vwherein'the invention is applied to a torch i in which the :mixture of .the gasesis e'ected in the handle. In this modification the handle 23 has a nozzle extension 24 having the usual conduit 25 for the commingled gases from the mixing chamber 26. The oxygen is discharged into the mixing chamber from an axial nozzle 27, surrounding which is the relief chamber 28, while the acetylene or combustible gas is delivered into the mixing chamber through the port 29 ahead of the oxygen nozzle. In this structure, the action is substantially the same as in the structures shown in Figures 1 and 2, for, under normal conditions, a partial vacuum is created in the relief chamber 28 during the operation of the torch, and the oxygen will back up in said chamber when an obstruction occurs in the outlet from the nozzle 24.

Obviously, the construction admits of considerable further modification without departing from the spirit of the invention which is characterized broadly by the relief of the pressure of the supporter of combustion for a limited period under abnormal working conditions, so as to prevent a flashllt) back or back-fire and during which time the neutral flame is still maintained. In other words, the principal object of the invention is to produce a torch or burner which rst of all mixes the gases so that equal or substantially equal volumes of the combustible and supporter of combustion, in the case of. acetylene and oxygen being used, o r, in the case of other gases, whatever proper proportions may be required to produce a neutral flame, are consumed at the nozzle or tip orifice, and will not back-fire under normal conditions, and yet if something` out of the ordinary occurs for a short interval will adjust itself' to those conditions and still not back-fire and will maintain the neutral iiame, but if the abnormal conditionspersist will indicate to the operator that the conditions .under which the torch or burner is operating are not conducive to good work.

What is claimed is:

1. In a gas burner or torch of the character described, means for supplying the combustible and the supporter of combustion in the proper proportions and pressures to produce va neutral flame from an orifice of a given capacity, and means for creating a vacuous relief for the supporter of combustion by the operation of the latter flowing S into the mixing chamber under normal conditions whereby to maintain the neutral flame under such conditions and whereby, also, the neutral flame continues for a limited period, but of proportionate lesser capacity, upon the occurrence of an abnormal restriction of the orifice. 2. In a gas burner or torch of the cha acter described, a mixing chamber, means for supplying the combustible and the supporter of combustion to said mixing chamber from separate sources and the supporter of combustion being admitted behind the combustible, and a relief chamber communicable with said mixing chamberl rearward of the inlet for the supporter' of combustion whereby to be evacuated by the operation of the supporter of combustion flowing normally into said mixing chamber.

3. In an Oxy-acetylene torch, a mixing chamber having an outlet for a flame of a given capacity, and the inlets for the acetylene and the oxygen being relatively proportioned toeach other and tothe size of the outlet from the mixing chamber to supply the acetylene and the oxygen in substantially equal volumes and pressures, the inlet for the oxygen being rearward of the inlet for the acetylene, and there being a relief chamber communicable with said mixing chamber and normally evacuated by the operation of the oxygen flowing into the mixing chamber, whereby a neutral flame is maintained*during normal operation, and whereby, also, the neutral flame' continues for a limited period, but ofI proportionate lesser capacity, upon theoccurrence of an abnormal restriction of the outlet 'from the mixing chamber for a limited period. y

l. In a gas b-urner or torch of the character described, a mixing chamber, means for supplying the combustible and the supporter of combustion to said chamber from separate sources and the supporter of combustion being admitted behind the combustible, and a relief chamber extending rearward axially of said mixing chamber and being communicable therewith rearwardof the zone-of enraros r; wiLLis.

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