US2367316A - Blowpipe and nozzle therefor - Google Patents

Description

Jan. i6, 1945.

y G. M. SKINNER BLOWPIPE AND NOZZLE THEREFOR @riginalV Filed'Feb. 27,

' ATTORNEY Aing a portion of the body, being Patented Jan; 16, 1945l 2,367,316 lBLOWPIPE AND NOZZLE THEREFOR George Skinner, Buffalo, N. Y., assignor to The Linde Air Products Company,- a corporation of Ohio Original application February 27, 1937, Serial No.

. 1940, SerialfNO. 329.008

11 Claims. ('C'l. 15S-27.4)

This invention relates to bloWp-ipes and nozzles therefor, and more particularly to blowpipes and nozzles useful in thermo-chemically remov.-

" ing metal from metallic bodies. This application body to a suilcientlyhigh temperature, usually,

designated as the kindling temperature, by means rof a high temperature preheating ame, such as that produced by the combustion of a mixture of oxygen and acetylene; andthen to direct a jet of anoxidizing gas, v'preferably pure oxygen, upon the portion previously heated to the kindling temperature so that the iron or steel upon which the oxidizing jet is directed Will be partially converted to the oxide and swept away by the action of the jet. Both the combustible mixture jet which. produces the heating flame and the metal removing jetof oxygen are normally discharged from the nozzle of a blovvpipe. By a progressive movement of the blowpip'e nozzle across the metallic body, a portion of the body may be removed and a cut produced along a line corresponding to the path of movement of the blowpipe. Such a method when utilized to sever a portion of the metallic body from the remainder -of the body Will produce a cut or kerf substantially corresponding in Width to the oxidizing jet, which in this instance has usually a velocity of 600 to 1800 feet persecond. In addition,such a'method may be employed in thermo-chemically removing metal from the surface of ametallic body, and in such instances the velocity of the oxidizing cutting jet is usually lower than the velocity of the jet utilized in completely severfrom 200 to 1000 feet per second.

However, since the upper edges of the kerf will not be maintained at the kindling temperature during cutting, due to the cooling action of the cutting jet, the lack of suicient rapidity of heat conduction through the steel to the upper edges of the kerf, and the usual presence ofmillscaleon the upper surface of the steel,\it is necessary to supply heat to the metal undergoing treatment, in addition to the heat produced by the combustion of the iron or steel. To supply this additional heat, it has been customary to ,utilize the preheating ilame used to heat a portion of the body to the kindling temperature. Such preheating names have heretofore beenpro- Divided and this application April l11,

duced by forming a combustible mixture of oxidizing gas and fuel gas, such as oxygen and acetylene, in a suitable mixer located in either the body or the nozzle of the blovvpipe, and directing this mixture from the nozzle onto the portion of the body to be treated; Such preheating ames, which usually have a velocity of from 200 Vto 500 feet per second, have a high rate of combustion and` a relatively high temperature; such names are also relatively hard, since primary combustion yof the Oxy-acetylene mixture is completed a relatively short'distance from the end of the nozzle.

A relatively high temperature and hard heating flame is unobjectionable Whenputilized to preheat a portion of a metallic body to thekindling temperature, but when utilized to provide supplemental heat during the removal of metal by the oxidizing jet, the resultant surface produced by the cutting operation tends to become rough and corrugated, and in the case of the complete severance of a portion ofthe metallic` body, the Walls of the kerf tend to become rough and corrugated, with pronounced drag lines, and the edges of the kerf tend to become rounded. The roughness of the Walls 'and the rounded edges of the kerf are produced hypl melting down of the edges due to the high temperature and the relative hardness of the preheating llames.

In addition, with such combustible mixture jets it is impossible entirely to eliminate flashbacks, With the attendantdanger of spoiling expensive shape-cut parts when the Work is partially finished. f

In my'copending application Serial No.` 128,117, now U. S. Patent No. 2,210,403, and also in the copending application of John M. Gaines, Jr., Serial No. 128,083, filed February 27, 1937, now U. S. Patent No. 2,210,402, there is disclosed a method of overcoming this objection by utilizing a diffusion flame to provide supplemental heat during theremoval of metal by the oxidizing jet. The diffusion ame is produced by directing, onto the metallic body1 a low velocity jet of combusti- A'ble gas adjacent the cutting jet, anda lovv velocity jet of oxidizing gas between the cutting jet and the combustible jet. The 10W velocity jets of combustible gas and oxidizing gas, which may have a velocity of 35 to 175 feet per second and preferably about 75 feet per second, intermingle outside the nozzle and burn with a Soft gentle flame, particularly adjacent the surface of lthe body, and liberate the greatest amount of heat Where the two jets come vtogether at the lip or edge of the kerf. A diffusionfame, when utilized to provide supplemental heat during cutting, produces a kerf having a smooth wall and sharp upper edges. In addition, jets mixing and burning outside the nozzle entirely obviate the danger of ba'ckres or flashbacks during the re moval of metal by the cutting jet, thus eliminating the'danger of spoiling expensive shape-cut parts when the work is partially finished.

A principal object of this invention is to provide suitable apparatus, such as a blowpipe, which is particularly useful in carrying out the above described method, wherein a diffusion flame is used to provide supplemental heat during the removal of metal from a metallic body by a jet of oxidizing gas or oxygen. Further objects of this invention are to provide such apparatus wherein the iiow of oxidizing gas to the diffusion flame is properly regulated; to provide such apparatus which includes means for producing a combusti.- ble mixture for initial preheating, and a diffusion flame for supplemental heating during the removal of metal; and to provide such apparatus w-hich is economical and eiiicient in operation. Other objects and novel features of this invention will become apparent from the following description and the accompanying drawing, in

which:

Fig. 1 is a vertical view, partially in section, of a blowpipe constructed in accordance with this invention;

Fig. 2 is an enlarged vertical sectional view of the lower end of the nozzle of the blowpipe of Fig. 1;

Fig. 3 is an enlarged horizontal view, looking upwardly, of the end of the nozzle of the blowpipe of Fig. 1;

Fig. 4 is a vertical view, partly in section, of the lower end of a modied form of a nozzle adapted for attachment tothe blowpipe of Fig. 1;

Fig. 5 is an enlarged vertical sectional view of another modied form of a nozzle also adapted for attachment to the blowpipe of Fig. 1.

As illustrated in Figs. 1 and 2, a nozzle N of a blowpipe may be'providedwith a central passage C through which a stream of oxidizing gas may be passed; an outer passage O through which a stream of combustible gassuch as acetylene, or a combustible mixture, such as a mixture of oxygen and acetylene, may be passed; and

an intermediate passageI through which a. stream r of oxidizing gas, such as oxygen, may be passed. The central passage C may be provided with an upper portion III and a restricted lower portion or outletr II by means of which a jet of oxidizing gas having a relatively high'velocity may be formed in a well known manner, the oxygen pressure in the upper portion Il) Abeing considerably greater than thevpressure in the lower portion I I, and the drop in pressure when passing into the restricted portion giving the oxygen stream the desired velocity. The outer passage O may be similarly provided with an upper portion I2 and a lower restricted portion or outlet I3 which is adapted to direct a jet of combustible gas or a combustible mixture substantially parallel to the' central jet and onto a portion of the metallic body adjacent that upon which the central jet impinges. i

In accordance' with this invention the supply of oxygen to the intermediate passage is derived from the oxygen passing through the central passage, such as by means of a plurality of connecting or inlet passages I4 which lead from the restricted portion II of the central passage into an enlarged portion or chamber I5 of the inter- '-used in producing a diiusion type flame. ,outlet I6 of the intermediate passage will direct mediate passage, from whence the diverted oxygen will flow through a lower restricted portion or outlet I6 of the intermediate passage. The chamber I5 not only distributes the gas equally around the periphery of the intermediate passage, but also reduces the velocity of the oxygen flowing therethrough, sincethe` velocity of the oxygen passing 'through' the lower portion of the central passage is considerably greater than that The a relatively'low velocity jet of oxygen between thecentrallcuttingjet and the outer combustible gas jet.` It will be apparent that due to this diversion from the central passage, oxygen will flow throughw the intermediate passage only when the cutting jet isemployed, and the flow of oxygen. through.' the intermediate passage will be regulated in accordance with flow through the central passage.

Also `in accordance:v with this invention, the diameters or relative dimensions of the connecting passagesi I4 may be so proportioned that a denite'predetermined amount of oxygen will be diverted from the central jet. In this way, the now of oxygen through the intermediate passage may be controlled so that theoptimum results will be produced when utilizing anyY given pressure in the upper portion of the central passage to produce a given velocity` and rate of flow of oxygen through the lower portion. It will be apparent that in some instances, such as in a nozzle adapted to` removemetal from the surface of a. metallic body in which the central cutting jet has a lower velocity and the lower restricted portion II is eliminated or relatively larger in diameter, itmay bedesirable to divert oxygen into the intermediatepassage from the portion I0 of thev central passage; .but it will also be apparent that in a nozzle adapted to utilize oxygen pressures. of any considerable amount, the lower pressure existing,` in the restricted portion will permit the usey of a greater number of connecting passages, which will tend to distribute the diverted oxygen more uniformly around the perilphery' of thev enlargedvportion' I5 of the intere mediate passage.l

The central passage Cwmay be formed in an inner or principal member I'I of the nozzle N; the intermediate passageI may be formed between the` lower portion of the inner member II and an intermediate member I8; and the lower portion ofI the outer passage O may be `formed between theintermediate member'l andan outermember I9. The outer member I9 maybe spaced from' theintermediate member I3 by suitable means, such as 1ugs120, and, if desired, the intermediate member4 I8 maybe similarly spaced from the inner member II. The upper end of the outer passage'Ov may consist of a plurality of longitudinal passages or inlets 2I, drilled in the member Il; and the members I8 and I9.may be secured to the' inner or principal member II by suitable means, such as by press fits over the circumferential portions 22 and 23, respectively. In addition, ther outlets I3 and I6` of the outer and intermediatepassages O and I, respectively, may be cylindrical, asis-more clearly illustrated in Fig.` 3, or may be formed as a plurality of small passages.`

In order to supply oxygen'an'd iuel gasto the various passagesA in the nozzle; the nozzle N, as in. Fig. 1, maypbesecured to ahead'H of a body B ofthe blowpipe by' a couplingnut 25in such` a man-nerxthat a central oxygenpassageiili formed in the head H is kin alignmentl withv the central` passage VCof the nozzle; and an outer passage 21 formed in the head Hterminates in an annular groove in alignment with a similar groove'formed in the nozzle N to form an annular chamber 28, from which connecting passages y29 lead to the inlets 2l.

In order to provide a mixture of oxidizing gas and fuel vgas in the vouter passage O for use during initialpreheating, an oxygen passage formed in the head H may lead to an annular groove aligned with a similar groove'formed in the nozzle N to form an annular chamber 3| from which a plurality of 4connecting passages 32 lead into the upperv end of the inlets 2|. In this manner a mixer is formed at the upper end of each of the inlets 2 I. By passing acetylene through the passageA 21, the annular chamber 28, and the connecting passages 29, andV simultaneously passing oxygen through the passage 30, the annular chamber 3| and the connecting passages 32, an Oxy-acetylene mixture will be directed through the outer passage O of the nozzle, and will produce ja high temperature heating flame, which when applied thereto, .will quickly bring a desired portion of -the metallic body to a temperature necessary for cutting or removal of a portion of the metallic body by means of a jet of oxygen directed from the central passage C. i Y

The upper end of the nozzle maybe conical in lshape and a conicalaperture'fo'rmed in the head H, having the same slope asthe upper end of the nozzle, so thatfwhent the nozzle is drawn tightly into the head by means of the nut 25, sealing surfaces 33v will be formed which will prevent leakage of gas from or to the central passage 26 and the annular chambers28 and 3|.

The body B of the blowpipe may bejprovided with an inlet connection 40, tohwhichma'y be connected a line adapted to deliver a" suitable supply of oxidizing gas, such as oxygen, and an inlet connection 4|, yto which may be attached aline providing a suitable supply of fuel gas, such as acetylene. Leading from the inlets 4D andV 4|, respectively, are passages42 and 43, formed-in a valve body V; and installed in the body V are shut-off lvalves 44 and 45, which are adaptedto prevent the owof gas through the passages 42 and r43, respectively, when the blowpipe is vnot in use. The valve 45 is `also adapted to be used y as a regulating valve for the fuel gas.

In further accordance with this invention,l a

' two-way valve 46 is installed in the valvebody V and utilizes the passage 42 as anfinlet. Valve 46 is provided with two outlets-an outlet .41, yto which is connected a tube 48 leading to Va valve body V lin which is installed'a regulatingr valve 49, and a secondl outlet 50. Tubes 5|, 52, and 53,`

respectively, connect the outlet 50, the passage 43, and the outlet 41 (through the tube 48 and valve' 49) With the central, outer, and intermediate passages 26, 21, and 30 of the head H. The valve 45 is adapted to regulatethe iiow of Afuel gas through the tube 52..to the outer passage O of thenozzle and the two-Way valve 46is adapted to permit the now of oxidizing gas through the tube 5I tothe central passage, or through -the tube 53 to the outervpassage O of the nozzle.

A valve chamber 54 for the two-way valve 46 is formed between `,a cap 55 and the valve body V, seats 56 and 51 being formed in the cap and the bodyV at eitherend ofv the Achamber 54.k When the two-Way valvel 46 is moved against the seat 56, oxygen will flow through the outlet 50, formed in the valvefbody V,.to the central .passage'C of the nozzle; and when the two-Way valve is moved against the seat 51, oxygen will flow through the outlet 41, formed in the cap 55, to the valve 4 and the outer passage O of the nozzle.

The valve body V is provided with a stem passage 58, through which a stem 59 of the valve 46 extends, the stem being provided with an enlarged threaded portion 69.- The walls of the stem passage 59 are threaded to cooperate with the enlarged threaded portion 60 of the stem so that by turning the stem the valve 46 may be moved to any desired position between the seats 56 and 51. vIn addition, a gland 6| may be provided, the gland being threadedly secured to the body V and adapted to retainpacking against the stem 59 to seal the stem during its moven ments. y

To deliver a combustible mixture through the outer passage O ofthe nozzle N for preheating purposes, the two-way valve 46 is moved against the seat 51, and the ilow of acetylene and oxygen to the outer passage O through the tubes-52 and 53 regulated by means of the valves 45 and 49,- h respectively. When the portion to be heated has reached the kindling temperature, the cutting oxygen is turned on by moving the valve.46 against the seat 56, the oxygen then passing through the tube 5| to the central passage C.

During the removal of metal by the oxygen directed from the central passage C, supplemental heat will be provided by the diffusion flame produced by the acetylene directed from the outer passage O and the oxygen diverted from the cen-v tral passage C into the intermediate passage I through the passages |4, as previously explained.

yIn case ay slightly higher temperature of the supplemental heating flame is desired, lsuch as in cutting at higher speeds or on rough surfaces, or inorder to prevent the formation of carbon def posits in the lower ends of outlets I3 and I6, the valve 46 may be adjusted so that it is spaced a small distance from the seat 56 and a small amount of the cutting stream of oxygen is di-A verted at the valve 46 and hows through the tube 53 and into the outer passage O. However, in

,such instances, it is desirable to limit the amount valve 46 during the cutting operation is rst determined, and a stop screw 62, having a threaded portion 63 in engagement with a threaded hole in the valve body V and adapted to abut againstl the end of the two-way valve adjacent the seat 56, is turned into engagement with the end of the two-Way valve and locked in position by a lock nut 64. rThe stop screw 62 may also be provided with =a packing gland similar to the gland 6| provided for the stem 59 of the valve 46. In utilizing the stop screw 62, it is set in position during the first of a series of` similar cutting operations. For subsequent cutting operations the two-way valve is merely seatedagainst the seat 51, the preheat mixture adjusted by means of the valves 45 and 49; and when the portion to be cut has reached the desired temperature, the cutting oxygen turned on and the required predetermined amount of oxygen in the fuel gas in the outer passa-ge automatically Obtai-d' by Ilvlg lthe two-Way Valve' into ablltI-iei'ltwith the 'Shop SCiW 62. During cutting, the required amount of 'Oxy'- gen to form the diffusion 'naine' will be diverted fromy the Cutting Stream through the passages lll, as previously described-i An alternative method of supplying a small predetermined amount of oxygen to the fuel gas during cutting is by meansof'one or more meter'- ing passages, such as vthe passages of the nozzles illustrated in- Figs. 4 and 5, which nozzles 'core respond to the nozzle of Figs. 1 and 2, except for passage 'H of Fig. 4 and passage 'l0 of Fig. 5. Passage 10 of Fig'. 5 leads from the enlarged portion l5 of the intermediate'passage I to the outer pas'- sage O. The passage 1i of Fignl' leads from the upper portion IU of the central passage to the outer passage O. Alternatively, suona passage may lead from the outlet Il of the central passage to the outer passage O.v In the last instance, the intermediate member` i8 may be shortened so that it willbe necessary to drill suchmetering passage or passages only through the inner member I'I. By diverting a. small predetermined amount of oxygen from the central passage into the outer passage, use of the stop-screw 62 of the two-#way valve is unnecessary, and the adjust'- ment of the amount of oxygen diverted into the fuel gas stream during cutting is notleft to the operator.

It Will be apparent that a mixer may be in stalled in the body of the blowpipe instead of being. formed in the upper end of the inlets 2|;

that other arrangements of valves may be used; and that other changes maybe made which will not depart from the spirit and scope of this invention.

What is claimed is:

l. In a blowpipe' for removing metal from'a metal body by the application of a heating flame to the body and the application of a metal removing oxygen jet to a heated surface portion of the body, a nozzle having a cutting oxygen pasfsage formed therein and having a restricted portion at the `Vdischarge end adapted to forni a metal removing voxygen jet; a second passage formed within said nozzle adjacent said firstename'd pas"- sage, said second passage having an enlarged pore tion and a restricted portion; at least one relatively small passage formed in said nozzle and leading froml the restrictedl portion of said first named passage to the enlarged portion of said second passage; and means for forming 'a comey bustible gas jet the combustion of which is spported by the oxygen jet discharged from said second passage.

2. In a metal` removing blowpipe av nozzle hav'-L ing an oxidizing gas passage formed therein; a second passage formed in said nozzle adjacent said rst-named passage; a third passage. for conibustilcilev gas, formed in said nozzle adjacent said second passage; at leas-t one passage formed ih said nozzle and leading from said first-named passage to said second passage; and at least one passage formed in said nozzle and leadingfrom said `ilrstenanied passage to said third passage to introduce oxidizing gas into the combustible gas inl said third passage, the relationship between said second and third passages being such that the jets discharged therefrom tend to mingle outside said nozzle and produce a combustible mixture adapted to burn to form a heating flame.

3. In a metal removing. bloivpipe, a nozzle hav'- ing an oxidizing gas passage formed therein and having' arestri'cted portion at th'edischarge end;

a-s`eeond` passage-'formed' 'Within said nozzle ad jacent 'said irs'tenained passage; a third passage, 'for combustibler gas,v foriied Within said nozzle suiiici'ently c-:losev to said second passageso that liets discharged from said second and third passagestndtoiriterrningle; at least one relatively small passage formed in said nozzle and leading f-rorn- 4said.'-firstfnamedI passage to said second passage; and'at least one relatively small passage leading from said second passage to said third passagey tointrloduce oxidizing gas into the combustible gas in said third passage.

4'.- In a metal removing blowp'ipe, a nozzle having an oxidizing gas passage formed therein provided with a restricted portion at the discharge end; a seoondpassage formed iris'aid nozzle adjacent said mst-'named passage, said second passage having an enlargedportion and a restricted dis'- chargek portion; a third passage, .for 'combustible gas,l formed in said nozzle adjacent 'said second passage; atleast one `relatively small passage formed in saidnozzleand leading vfrom the restrict'ed portion of said first-named passage to the enlarged portion of said second passage; and lat least'one relatively small passage leading from therenlarged portion'of said second passage to said third passage to introduce oxidizing gas into the combustiblevgas iny said third passage.

5. A blowpipe for removing metal from metallic bodies, said blowpipe having a passage provided with an outlet for* discharging a, cutting jet of oxidizing gas against'a portion of a metal body; a second passage vprovided with an outlet normally-for discharging a jet of combustible gas against said'` body adjacent said rst-named jet;

means for diverting a portion of the gas flowing through said oxidizing gas passage and convey'- ing such diverted portion to a third passage havingran outlet 4for discharging av jet of oxidizing gasto support the combustion of said combustible jet,said outlets beingso arranged that the combustion-supporting jet -is directed between saidl cutting jet and said combustible gas jet; and means for selectively supplying oxidizingv gas to said r-st-'named passage and/ or said second passage.

6i -A blo'wpipefor removing metal from a metallic body. comprising'means for mixing a stream ofi-fuel gas and-astreamof oxidizing gas to form aieombustible mixture; means for directing such mixture as a heating jet onto a portion of said body to be cut solas to raise such portion to a predetermined kindling temperature; means for directing a second stream of oxidizing-gas as a cutting jet onto said heated portion; means for discontinuing said rst-named oxidizing gas stream; means for diverting a portion of said second oxidizing gas stream and directing such diverted portion into said fuel gas stream so as to form a combustible jet having a relatively large proportion of fuel gas and arelatively small proportion of oxidizing gas; and means for simultaneously diverting. a second portion of said second oxidizinggas stream and forming a separate jet of -roxidizinggasdirected upon such portions beingY removed.

rI. In a, metal-removing blowpipe, 'a'- nozzle having lan oxidizing gas passage formed therein, a secondoxidizing gas passage formed in said nozzle adjacent -said firstenamed passage, a third passage for combustible gas, formed in said nozzleradjacent saidisecond passage, at least one relatively small passagev formed in said nozzle and leading'` from saidrstenamed passage to said second.4 passage,- and'- at least 'one relatively small passage leading from said second oxidizing gas passage to said third passage to introduce oxidizing gas into the combustible gas in said third passage. l 8. In a metal-removing blowpipe, a nozzle having an oxidizing gas passage formed therein,

a second oxidizing gas passage formed in said nozzle adjacent said rst-named passage, a third passage for combustible gas, formed in said nozzle adjacent said secondl passage, and relatively small passages formed in said nozzle, one small passage extending between said rst-namedoxidizinggas passage and said second oxidizing gas passage to supply the latter passage With oxidizing gas, and the other small passage extending between said rst-named oxidizing gas passage and said third passage to introduce oxidizing gas into the combustible gas in said third passage.

9. A blowpipe including a nozzle, said nozzlev having a first passage provided with an outlet passage provided with an outlet for discharging for discharging a high velocity cutting stream of oxidizing gas, a second passage provided with an outlet normally for discharging a hard jet o" premixed preheating gases adjacent said firstnamed passage, and a third passage for dischargi ing a low velocity stream of oxidizing gas to be mixed externally with a stream of combustible gas to provide a soft supplemental heatingame, means for supplying combustible gas to said 4second passage, means for selectively supplying oxidizing gas/to `either said first-named passage or said second passage, said nozzle having passage means kbetween the rst and third passages for diverting a small portion of the oxidizing gas from said first-named oxidizing gas passage to the third passage to support combustion of the relatively large flow of combustible gas so as to provide automatically the soft supplemental heating flame after the flow ofoxidizing gas to said second passage is reduced by the selective means and thehard preheating jet dispensed with.

a cutting stream of oxidizing gas against a-metal body, asecond passage provided with an outlet normally for discharging a jet of preheating combustible gas against thev body adjacent said stream, means for selectively supplying oxidizing gas to either said first-named passage ory said second passage, means for conducting a ,combustible gas to said second passage, said nozzle having a relatively small passage for diverting a small portion of the oxidizing gas from said rstnamed passage to mix with the combustible gas in the second passage so as to provide a soft heating flame after the flow of oxidizing gas to said second passage is discontinued by the selective means. y i

11. A bloWpipe including a nozzle, said nozzle having a rst passage provided With an outlet for discharging a kcutting stream of 4oxidizing gas, a second passage provided with an outlet for discharging a jet of premixed preheating gases adjacent said cutting stream, and a third passage for discharging a stream of oxidizing gas to be mixed externally With a stream of combustible gas from saidsecond passage to provide a heating flame adjacent said cutting stream, means for supplying combustible gas to said second passage, and means for selectively supplying oxidizing gas to either said rst passage or said second passage, said nozzle having passage means between the first and third passages for diverting a portion of the oxidizing gas from said rst passage to the means.v

GEORGE M. SKINNER.

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