US1248895A - Burner and method of overcoming flame propagation therein. - Google Patents

Description

C. I. NYQUIST. BURNER AND METHOD 0F OVERCOMING FLAME PROPAGATION THEREIN.

APPLICATION FILED OCT. 9. i916.

Patnted IDe. 4I, 191?.

IIIIIIIIIIII N I I. zr' n Q y1@ fnrrrrn sa tirar 1 marron CARE d'. NYQ'UIIST, OF LUS ANGELES, UALFORNFA.

BURNER AND METHOD 0F VERCOMNG FLAME FRFGTON THEREFN'..

To all lwhom it may concern.'

Be it known that l, CARL J. NYQUIST, a citizen of the United States, residing at Los Angeles, in the -county of Los Angeles and Sta te of California, have invented a new and useful Burner and Method of @vercoming Flame Propagation rllherein, oitn which the following is a specification.

' An object ot this invention is to make provision for overcoming the 'so-called flashback or propagation of the f" flame 'in the lli ' bodying the invention.

burner toward the source of -supply oi the combustible gas employed in the device, thus minimizing danger in the use of the burner and also avoiding injury to the burner caused by :thelash-back.

Another object is to make provision for the utilization of the pressure of the ignited gases due to the Hash-back to extinguish the flame in the burner. y

@ther objects and advantages will appear in the subjoined detail description.

'lhe accompanying drawings illustrate the invention., a

Figure l is a side view of a burner em- Fig. 2 is a longitudinal mid section of said burner.

vFig. 3 is an enlarged sectional detail of the intermediate portion oi the burner.

Fig. l is a transverse section on line indi- 'cated by m4-mt, Fig. 3.

Fig. 5 is a transverse section on line indicated by @2L-005, Fig. 3.

Fig. 6 is a transverse section on line cated by m0-, Fig. 3.

Fig. 7 is a side view ot the primary mixing chamber. ,y lt is well'known that, in mixing a.com bustible gas and a combustion-supporting gas together suclnior example, as acetylene and' oxygen in a burner, varying ressures or other causes, possibly -all of w ich are not known, tend :to cause the flame oryburn-4 ing mixture to Hash back throu h theburner and establish a flame at the in et where the combustible gas discharges into the burner,

thus producing intense heat adjacent said inlet. ylhis Hash-back occurs in gas stoves,

Bunsen burners and also in Oxy-acetylene cutting and 'welding tools. The flash-back in stoves and lBunsen burners is not especially detrimental tothem, but

in Oxy-acetylene' torches the heat oli the dame Specification of Letters Patent.

indiraten-rea nee, a, reir.

Application flied october 9, 1916. Serial No. 1241:,466.

established by flash-back lin the burner is sufficient to melt or ruin the parts of the torch adjacent they flame.

Efforts have been made to insure against flash-backs in oxy-acetylene torches bv interposing ioramino'us disks or equivalent or some suitable non-combustible filtering material between the gas inlets oit the mixing Achamber and the discharge end ci the nozzle.

llt is obvious that oram-inous disks or other flow-obstructing devices so placed greatly re- 'duce the pressure so that much greater pres sures are required to be maintained in the gas reservoirs or supply hose than is necessary where such toraminous disks or other obstructions are omitted. The ioraminous `disks, although they may be successful in preventing name propagation in a burner with some gases, are unsuccessful where oxygen and acetylene gases are employed.

Ylhis device does not prevent the occurrence ot {lash-backs, but the constructionl is such that the torce of some of the expanded gases due to the flashback is exerted against the ameestablished by said 'flash-back so as to extinguish it immediately as soon as it occurs, thus preventing the parts adjacent the flame from becoming heated to such' an extent as to destroy or ruin them.

,. -lin the drawings the invention is embodied" in a torch adapted to use oxygen and acetylene gases, but it is understood that certain teatures of the invention are not limited to the\to rch shown or tothe mixing and burningfot only these gases.

There is provided a suitable mixing Vchamber l which may be substantially cylindrical as shown in the drawings or of other suitable Jorrn, said mixing chamber being provided at its rear end with a rearwardly expanding' axial inlet 2 and near said inletv with other gas inlets 3 that extend aslant forward and inward from the periphery of the mixing chamber .to the `interior thereof'. rllloe mixing chamber is surrounded between the gas inlets 3 and its outlet 1l with an annular flash-back chamber or pocket 5, there being an injector port (i extending. aslant inward and forward from the dash-back lill@ chamber .into the mixing chamber so that the iiash-back chamber communicates with the mixing chamber., v

The mixing chamber l has its forward end inserted in a socket i, the inserted end being of slightly rless diameter than the diameter of the socket so as to leave a slight annular flash-back passage 8 between the mixing chamber and the wall of the socket 7. The annular passage 8 is not absolutely essential to the eective operation of the burner but such construction is sometimes preferable. The socket 7 is formed in the rear end of a hollow 4stem indicated in general by the character 9, said stem having if'desired a bend 10v near its' outer end and said outer end being provided with a suitable nozzle 11 which is connected by screw-threads or otherwise to the stem. The bore of the stem 9 is contracted at 12 adjacentthe socket 7 and is also contracted at 13 at its outer end adjacent the nozzle 11 and is expanded at 14 intermediate the contracted portions 12, 13, the contracted portion 12 being of greater diameter than the bore of the mixing chamber 1. The portion l15 of the bore of the nozzle adjacent the stem 9 is expanded and is of larger diameter than the bore portion 13 of the stem and the tip portion 16 of the nozzle bore is contracted.

The bore portions 12, 13, 14, 15,l 16 in reality constitute an auxiliary mixing chamL ber as will be made` clear hereinafter. The.

stem 9 is provided with a threaded portion 17 terminating at a shoulder 18, said portion 17 being screw-threaded into a cylindrical or other suitably shaped body forming a front head indicated in general by the character 19, and a portion of said cylindrical Abody forming the iiash-back chamber 5.

The rear end of the mixing chamber 1- is screw-threaded at 20 into au axial passage 21 of the body 19 which is )rovided rearward of the ash-back cham er 5 with an annular chamber 22 surrounding the mixing chamber adjacent lthe gas in ets 3.

Into the passage 21 is fastened by brazing or any suitable means or method a gas tube 23 and into the annular chamber 22 ex'- tends and is fastened a gas tube 24. The rear ends of the gas vtubes 23, 24 are brazed or otherwise fastened into a rear head 25, there being ducts 26, 27 in said head communicating with the gas tubes 23, 24q respectively. The head 25 isprovided with valves 28, 29

which are connected to suitable sourcesA ofl gas supply, not shown, said valve 28 controlling the supply of one ofthe gases, for in? stance oxygen, to the duct 26 andsaid valve 29 controlling the supplyof another gas, for instance acetylene, to the duct 27 Surrounding the tubes 23, 24 is a casing 30 which may be of cylindrical or other suitable shape and which is brazed or otherwise fastened at one endfto the head 25 and` at the other endto thefbodv 19. In practice, assuming that the valves 28,

' 29 are connected to suitable sources of gas supply, not shown, for example, oxygenpand acetylene respectively, the operationofthe device is as follows: The workman using the c torch, having rst selected a nozzle and mixing chamber having the predetermined cross sectional area of bore for the size of the work to be operated on, will open the valves 28, 29 and will ignite the gaseous mixture issuing from the nozzle 1l, and he will also adjust the gas pressures (in a manner well understood in the art) so as to obtain with this device evenly balanced pressures and volumes of the gases, and v'he will hold the torch so as to direct the flame wherever desired. Gas iows through the tube 23, thence through the inlet 2 to the mixing chamber 1 and the other gas ows through the tube 24, thence into Ath'e chamber 22 and thence through the inlets 3 into the mixing chamber. The gases issuing from the inlets 2 and 3 mix in the mixing chamber 1 and then expand into the bore portion 12 of the stem,

from whence the mixture flows into the bore portion 14, expanding therein. From the bore portion 14 the mixture flows into the bore portion 13, being accelerated therein, and then flows into the nozzle bore portion 15 which allows it to expand, thereby diminishing the velocity of its How. Finally said mixture flows from the nozzle bore portion 15 through the reduced nozzle bore portion 16 where it: is again accelerated, and the mixture issuing from said bore portion 16 ignites to maintain the iiame.

It is thus clear that as the mixture Hows from the mixing chamber 1 to the tip of the nozzle 11 the fiow of said mixture is alternatively accelerated and retarded, the retardation being eHiected by reason of the mixture being allowed to expand in the bore portion 14 of the stem and bore portion 15 .of the nozzle, and the acceleration being due ber 5 to form a pocket of explosive gaseous mixture so that, if for any reason the fiame at the top of the nozzle iashes or strikes back through the nozzle and stem bores into the mixing chamber, said flame-will reach the ash-back chamber 5 before .it reaches the gas inlets 2, 3, thus causing an explosion of the mixture in the Hash-back chamber.

lThe forceof said explosion drives some of the exploded lgases through the port 6 into the mixing chamber and thence outward rthrough said mixing chamber. The force of the expanded gases -issuing from the port 6 into the bore of the mixing chamber is sufficiently great to producea partial vacuum in that portion of the mixing chamber extending between the port Gand inlets 2, 3, thus producing a suctlon sufiicient to lextinguish ioo lill

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naaaeea any flame that may possibly have been propagated through the bore of the mlxmg chamber to the rear ot' the port 6 when the flash-back occurs. v

When the explosion occurs in the Hashback chamber the burnt gases are expelled with great force through the port 6, making a partial vacuum in the flash-back chamber, and are directed outward by said port, which in reality functions as an injector, so as to blow the flame outward away from the 1nlets2, 3, thereby extinguishing the flame because ot' the absence of a combustible mixture to `feed it, but immediately after the flame is thus extinguished the combustible mixture quickly fills the mixing chamber and flash-back chamber as before and flows to the nozzle.

'llhe flash-back and subsequent extinguishment of the flame ot' the flash-back occur in an exceedingly small frac-tion of time so that the gaseous mixture issuing from the tip of the nozzle is readily ignited again by reason ot' the heat of the metal that is being worked upon not having time to dissipate suliiciently to lower the temperature thereof below the degree necessary for ignition of said mixture.

4llt is understood that the annular p-assage 8- also fills with the mixture and that owing to the provision of said annular passage, when the Hash-back occurs the iiame may be propagated from the socket 7 through said annular passage to the Hash-back chamber 5, and that some of the force of the subsequent explosion of the mixture in the flashback chamber may expend itself outward through said annular passage. Of course owing to the mixing chamber being spaced from the wall `ot' the socket 7 said wall is more or less insulated against the conduction of heat from the mixing chamber.

From the foregoing it is clear that the invention not only comprises the construction hereinbefore described 'but also comprises the method of overcoming flame propagation in burners by utilizing the propagated .Haine to explode a quantity of the gaseous mixture and then utilizing the :torce of the expanded gases due to the explosion to blow out the propagated flame in the burner.

llt is clear that the mechanical embodiment" of the invention may be otherwise than shown and described and-it is understood that the invention is only limited' by the spirit and scope of the appended'claims.

The interior of the casing which forms a handle for holding the device communicates with'the atmosphere through an opening or openings 3l in the head 25. j

The hereinbefore described speciic con'- struction'ot vthe chamber 22 and gas inlets 2, 3 and the described construction of the stem 9 and nozzle 11 is of advantage as 'an aid in maxumzmg the edectweness of the torch when used with evenly balanced pressures. This enables lower` pressures to be employed for work of a given size, and the advantage of using the lower pressures is that the metal being operated on will not be blown away and disturbed by the welding ame as results where higher pressures are employed; also oxidation of the metal at the weld is minimized. 'llhc points of construction just noted above also conduce to minimization tin the consumption lof the gases employed.

l'. claim: f* l. The method of overcoming flame propagation in a conduit which consists in collecting an explosive charge, exploding said charge when a Hash back occurs and directing the exploded gases into said conduitin a direction contrary to the direction of movement of the Hash back, to blow out the llame.

2. rThe method of overcoming Hame propagation in a conduit which consists in collecting an explosive charge near the entrance to said conduit, exploding said charge when a flash back occurs by the flash back and directing the vexploded gases into said conduit in a direction contrary to the direction of movement of flash back to blow out the flame.

3. A burner comprising a mixing chamber having as inlets and an outlet, and means where y when flash-back occurs the torce of the gases exploded by the flash-back will operate to blow out the flame in the burner.

'4. A conduit at the end of which gas passed therethrough is burned, means for receiving explosive gas and of such volume as to produce an explosion when flash-back loccurs, and means for directing said explosive gases toward said end whereby the flame in the conduit will be blown out.,

5. A burner comprising a mixing chamber having gas inlets and an outlet, a iashback pocket communicating with the mixing chamber, and a socket adjacent the outlet of the mixing chamber communicating with ,the flash-.back pocket.

6. A conduit at the end of which gas passed therethrough ris burned, said conduit having gas inlets, means located belll@ lith

tween said end and said inlets for collecting explosive gas to produce an explosion when flash back occurs, and means for directing said explosive gases toward said end, whereby the dame in the conduit will be blown out.

7. A burner comprising a mixing chamber having gas inlets andan outlet, a flash-back pocket communicating with the mixing chamber, a socket adjacent the outlet of the mixing chamber vcommunicating with the 'Hash-back pocket, and a nozzle communicating with the socket.

8. A burner comprising a lmixing chamber having gas inlets and an outlet, and a Hash-back chamber, there being a. port opening from the flash-back chamber into the mixing chamber and extending aslant inward and forward toward the outlet.

9. A burner comprising a mixing chamber having gas inlets and an outlet, a flashback pocket, there being a port opening from the Hash-back pocket' into the mixing chamber and extending aslant inward and forward toward the outlet, and a socket adjacent thel outlet communicating with the flash-back pocket. Y

10. A burner comprising a mixing chamber havinggas inlets and an outlet, and means whereby to hold a gaseous mixture so that the explosion thereof'by-iiash-back through the burner will operate to blow outl the flamefthus established in the burner.

.11. A conduit at the end of which gas passed therethrough is burned, said conduit having gas inlets, a pocket, and a passage extending from said pocket into said conduit between said end and said inlets,l and converging relative to the conduit in the direction of the flow of gases therethrough, said pocket being constructed and arranged to receive explosive gas .and of such volume as to produce an explosion when ilash back occurs. v 12. A burner comprising a body having a passage and having a chamber .and a pocket, and a mixing chamber having an axial bore and inserted in said passage, said mixing chamber having .an inlet communicating with said passage and having an inlet communicating with the body chamber and hav-J1.

ing a portk communicating with the pocket.

13. A burner comprising a mixing chamber having gas inlets andan outlet, a port opening into the mixing chamber, and a flash-back chamber communicating with said port ,and extending rearward thereof toward the gas inlets, the rearward extending portion of said flash-back chamber bep ing closed.

14. y A burner comprising a body having a Hash-back pocket, a hollow stem having asocket at one end and fastened to the body, and a mixing chamber fastened to said body and projecting therefrom into Asaid socket and provided with gas inlets and communieating with said socket and with the Hashback pocket.

15. A burner comprising a body having a flash-back pocket, a hollow stem having a socket .at one end and fastened to the body, and a mixing chamber fastened to said body and projecting therefrom intosaid socket and spaced apart from the wall of the socket to leave an annular passage and provided with gas inlets and comunicating with said socket and with the Hash-back pocket.

16. A burner comprising a body having a flash-back pocket, a hollow stem having a socket at one end and fastened to the body,

and a mixing chamber fastened to said body and projecting therefrom into said socket and provided with gas inlets and communieating with said socket and with the iiashback pocket, said socket communicating with the flash-back pocket.

17. A burner comprising a body having a flash-back pocket, a hollow stem having a socket at one end fastened to the body, .and a mixing chamber fastened to said body and projecting therefrom into said socket and spaced apart from the wall of the socket to leave an annular passage and provided with ga's inlets and communicating with said socket and with the flash-back pocket, said socket communicating with the dash-back pocket. v

18. A burner comprising a flash-back pocket, and a mixing chamber extending through said flash-back pocket and provided with gas inlets and an outlet and provided between the outlet and the inlets with a port communicating with the Hash-back pocket.

19. A burner comprising a body having a flash-back pocket, a hollow stem fastened -to said body .and extending into said pocket CARL J. NYQUIST.

Vitnessesz.

GEORGE H. HILns, A. F. SCHMIDTBAUER.

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