US2654329A - Blowpipe employing adjuvant powder for thermochemically removing material - Google Patents

Description

Oct. 6, 1953 D. H. FLEMING, JR 2,654,329

BLOWPI EMPLOYING ADJUVANT POWDER FOR THER HEMICALLY REMOVING MATERIAL 2 Sheets-Sheet 1 Filed July 2, 1946 fl Z2 719 INVENTOR DAVID H. FLEMING,JR. BY

ATTORNEY 1953 D. H. FLEMING, JR 2,654,329

BLOWPIPE EMPLOYING ADJUVANT POWDER FOR THERMOCHEMICALLY REMOVING MATERIAL Filed July 2, 1946 2 Sheets-Sheet 2 IN TOR ATTORNEY DAVID H. EMING,JR.

Patented Oct. 6, 1953 BLOWPIPE EMPLQYING ADJUVANT POWDER FOR THERMOCHEIVIICALLY REMOVING MATERIAL David H. Fleming, Jr., Orange, N. .L, 'assignor, by mesne assignments, to. Union Carbide, and Carbon Corporation, a corporation of New York Application July 2,v 1946, Serial No. 680,982

17 Claims. 1

This invention relates to thermochemical material removal, and more particularly to apparatus employing adjuvant powder in conjunction with oxy-acetylene material removal to facilitate the thermochemical reaction.

Forintroducing the adjuvant powder, it has been proposed to project the same in admixture with a carrier gas in one or more jets on the leading side of the oxygen jet. With this expedient, any irregularities in powder distribution or preheat flame velocity would result in deflection of the powder stream and cause the start or out to be made in a diflerent plane from that of the oxygen stream.

It is therefore the main object of the present invention to avoid these difficulties, and to cause the adjuvant powder to closely surround the material-removing oxygen stream.

Another object is to provide an adaptor which makes it possible to do powder cutting with a standard cutting nozzle as Well as to adapt such nozzles for powder starting.

Other objects are to facilitate the projection of the adjuvant powder through the preheat envelope toward the oxygen stream, and to simplify and improve the construction and operation of apparatus for this purpose, to provide the apparatus in the form of a convenient attachment for blowpipe nozzles of general utility for machine type blowpipes, and to provide a light-weight adsurface of a body of such material, for example carbon steel, low alloy steel, or stainless steel, as by cutting, flame machining, or'boring, by directing against a region of the surface of said body on said path where the operation is to begin a preheat flame envelope, directing a plurality of streams of adjuvant powder from outside said preheat flame envelope in converging relation through'said preheat flame envelope as elements of a cone to heat said powder to its oxygen igni-' tion temperature, directing a stream of material removing oxygen against said body from within said preheat envelope and coaxial with said cone to propagate the heat of combustion of said pow-'- der to said body.

The adjuvant powder comprises a highly combustible material such as powdered iron, low carbon steel, cast iron or ferro-manganese and mixtures of such metals with one another and with other materials, such as aluminum or manganese.

The oxygen, preheat t nvelope, and powder stream may be applied simultaneously, or in any desired sequence. For quick starting, for example on carbon steel, the powder may be turned off as soon as the cut is started, and the cut con: tinued with oxygen and preheat flames alone. But for cutting stainless steel, for example, it is desirable to continue the powder stream, after the out has been started, and progress the stream of oxygen, preheat flame envelope, and adjuvant powder stream along the path of out while maintaining constant their relation to each other.

The present invention employs a plurality of orifices located, in a circle surrounding the oxygen stream and inclined at an angle thereto. The adiuvant powder jets form elements of an imaginary cone with its apex below the end of the nozzle to form a continuous envelope of powder surrounding the oxygen stream. The adjuvant powder is discharged at velocities great enough to; cause the powder to either pass through the preheat envelope or be entrained with it, thus closely surrounding the central oxygen stream.

Other objects and features of novelty will be apparent as the following description proceeds, with reference to the accompanying drawings in which:

Fig. 1 is a longitudinal section through the preferred embodiment of apparatus according to the present invention, showing the same as an attachment for a conventional oxy-fuel cutting nozzle;

Fig. 2 is a transverse section taken along the line 22 of Fig. 1;

Fig. 3 is a bottom plan of Fig. 1;

Fig. 4 is a detail elevation of a portion of the powder nozzle shown in Fig. 1;

Fig. 5 is a detail perspective view of the powder distributor ring member shown in Fig. 1;

Fig. 6 is a longitudinal section through a modification showing the special powder nozzle em.- ployed for hand blowpipes;

' Fig. '7 is a transverse section taken along the line T'! of Fig. 6;

Fig. 8 is a bottom plan of the nozzle shown in Fi 6; and i Fig. 9 is an exploded View of the parts of the nozzle shown in Fig. 6.

As shown in Fig. 1 the central material-remove ing oxygen stream 0 is surrounded by a plurality of oxy-fuel preheat flames F which form a preheat envelope surrounding the central oxygen stream O, the gases being projected by an oxy fuel nozzle N having a central high pressure oxygen passage and an annular row of flame passages encircling the oxygen passage for discharging combustible gaseous mixtures. The adjuvant powder is introduced from a plurality of orifices D arranged in a circle outside of and concentric with the preheat envelope, and inclined inwardly to project a plurality of adjuvant powder jets P positioned as elements of a cone having an axis coincident with the axis of the oxygen stream and the preheat envelope formed by the flames F. The apex A of the cone is below the end of the nozzle N.

The jets of adjuvant powder in this conical arrangement are blown through the preheat envelope between successive flame jets F, as indicated by the exit orifice arrangement in Fig. 3, and converge into the oxygen stream beyond the end of nozzle N to form a continuous envelope of powder closely surrounding the central oxygen stream. The velocities of the jets P are great enough to either pass through the preheat envelope or become entrained with it, and thus closely surround the central oxygen stream. The adjuvant powder is thus ignited by the preheat flames, as the powder streams P converge toward the apex A, and burn in the oxygen stream 0 to form a single stream of burnin powder coincident with the central oxygen stream 0.

The included angle of the cone should be less than 90 and more than 40. With more than 90 sintering difficulties are encountered, because small eddy currents tend to carry the stray powder particles back onto the face of the powder nozzle and cutting nozzle, with the danger of eventually forming an accumulation that blocks off the powder orifices, or cutting oxygen and preheat orifices. With less than 40 included angle there is not sufficient mixing action and the powder does not tend to pass through the preheat envelope. An included angle of between 45 and 65 degrees is the optimum range for the best results, within the preferred range of 40 to 90, although the process may be operative over a still broader range.

The circle diameter on which the adjuvant powder orifices D are located must be large enough to eliminate the possibility of the preheat envelope heating the powder particles to a sintering temperature immediately as they issue from the powder nozzle which would cause a sealing off of the powder orifices. But the circle diameter should be small enough to prevent the powder jets from intersecting the oxygen stream too far below the end of the nozzle so as to cause insufficient mixing of the powder and oxygen for efiicient operation.

In the embodiment shown in Figs. 1-5, the adjuvant powder is supplied by a powder nozzle adaptor C, which is an attachment fitted to a conventional blowpipe having a body 13 which receives the nozzle N. For supplying the adjuvant powder thereto, a powder supply tube T runs along the outside of the body and is connected to the powder nozzle adaptor C.

The powder nozzle adaptor C comprises an inner annular body 15, which is mounted on a sleeve i2, preferably formed of a stainless steel tube on which a nozzle nut I4 slides. The upper end of the sleeve 12 has an annular rim 15 which retains the not It thereon, and which when the nut is tightened, bears against a shoulder i6 on the nozzle N.

The inner annular body 10 surrounds the sleeve l2 and is secured thereto for example by silver soldering. An outer cap 22 is fitted over the outside of the body it and secured thereto by screw threads. The body Ill and the cap l2 have r s 4 tering portions forming an annular powder inlet chamber 25 in communication with diametrically opposed inlets which receive fittings 25 for branches 25 of the powder supply tube T.

Below the inlet chamber 25 the body l5 and the cap 22 have registering grooves offset inwardly to form a lower annular powder distributing chamber 2?, and to provide annular shoulders to receive therebetween a distributor ring 28 having spaced apertures 25 for distributing the powder uniformly around the lower chamber 2?.

Below the ring 28' the cap '22 has a conical inner face 35, and the body It! has a mating conical face 3| provided with spaced grooves 32 forming elements of the cone. The grooves 32 lead from the distributor chamber 27 to the discharge orifices D.

For sealing the upper powder inlet chamber 25 the body [0 and the cap 22 have opposed annular shoulders to receive a metal bearing ring 33 and a resilient packing ring 35 which is compressed when the cap 22 is tightened on the body The inner body Ill of the powder nozzle adaptor also has an internal annular cooling jacket 35 having an inlet passage 35 leading from a cooling medium inlet fitting 3'1, and an outlet passage 38 leading to a cooling medium outlet fitting 39.

The form shown in Fig. 6 is adapted for hand operation.

In the embodiment shown in Figs. 6-9, the blowpipe head H has a passage 42 for cutting oxygen, a passage 43 for preheat gas, and a passage 44 for adjuvant powder. The powder passage 44 has a branch 45 which communicates with an annular powder inlet chamber 45 formed by an internal annular groove in the blowpipe head H.

In this embodiment the powder nozzle comprises an inner body member 55 which is formed with a longitudinal oxygen passage 5! and preheat passages 52 grouped therearound as in a conventional cutting nozzle. The lower end of the member 50 is tapered to form a conical face 53 which has grooves 54 cut therein and forming elements of the cone. As shown in Fig. 8, the grooves 54 are angularly spaced between the preheat passages 52.

Surrounding the inner member 55 is an outer sleeve member 55 which is provided with a conical seat 56 at the lower end of its bore, which con tacts the conical face 53 of the inner body 55 between the grooves 54. There is a clearance between the inner member 55 and the outer sleeve 55 above their conical faces, which forms an elongated annular distributing chamber 51 for distributing the powder to the grooves 54.

The outer sleeve 55 has a shoulder 60 at its upper end which is engaged by a nozzle nut 6i, and the inner body 50 has a shoulder 62 which is engaged by the upper end of the outer sleeve, so that the nozzle nut clamps both parts in position in the blcwpipe head H. The annular powder inlet chamber 46 is sealed by an upper gasket 66 between the shoulder 62 and the blowpipe head, and a lower gasket 61 fitted in a groove 68 in the outer sleeve 55 below the upper end thereof. The powder inlet chamber 46 communicates with the powder distributing chamber 51 through passages formed by longitudinal grooves 10 formed in the shoulder 62 and the outer face of the upper end of the inner body 50. As shown in Fig. 7 the grooves 15 are spaced between the preheat passages 52.

With apparatus according to the present invention stainless steels can be cut at speeds at least equal to those heretofore obtained with carbon steels for the same thickness. This results in an improvement of approximately 50% over the results heretofore obtained.

It is possible to produce kerfs which are at least 30% narrower than those heretofore produced. I

In the operation of either the hand cutting nozzle or the machine cutting powder attach= ment, too great a preheat gas velocity results in the dispersion of the powder and the production of wide kerfs and unsatisfactory appearing surfaces. Therefore it is possible with the present invention to reduce the preheat gas consumption 7 to a fraction of that used on carbon steels and consequently less than has heretofore been used in powder cutting. Relatively short low-velocity preheat flames are used. By passing the powder through the preheat envelope, more eiiicient heating of the powder is obtained and therefore greater overall efiiciency results.

The entire nozzle is very rugged and may easily be dismantled for cleaning by merely pulling the internal out or the external sleeve. No packing is necessary because gas-tight seats between the internal and external parts are not employed.

The various powder passages in the attachments are proportioned to give a minimum powder-air mixture velocity in order to keep the powder continuously entrained and provide equal distribution from the exit passages. The exit jets are proportioned to impart sufficient velocity to the powder-air mixture so that the mixture can be blown through the preheat envelope at minimum air flow conditions.

What is claimed is:

1. Apparatus for thermochemical removal of material from a body of such material which comprises means for directing against said body a stream of material-removing oxygen and a preheat flame envelope surrounding said oxygen stream, and means for directing a plurality of streams of adjuvant powder from orifices equally spaced around and outside said preheat flame envelope in converging relation through said preheat flame envelope toward said oxygen stream with components concurrent with said oxygen stream.

2. Apparatus for thermochemical removal of material from a body of such material which comprises a nozzle having a longitudinal oxygen passage for directing against said body a stream of material-removing oxygen, said nozzle having a group of preheat gas passages surrounding said oxygen passage for directing against said body a preheat flame envelope surrounding said material-removing oxygen stream, and means forming a ring of orifices equally spaced around and outside of the outlets of said preheat gas passages for directing a plurality of streams of adjuvant powder through said preheat flame envelope in converging relation with components concurrent with said oxygen passage and having an apex below the outlet end of said nozzle.

3. Blowpipe apparatus comprising a nozzle having a longitudinal oxygen passage and a group of preheat gas passages surrounding said oxygen passage, and an annular member surrounding said nozzle and machined to form a plurality of adjuvant powder passages equally spaced around said nozzle with components concurrent with said oxygen passage and converging to an apex below the outlet end of said nozzle.

4. Blowpipe apparatus as claimed in claim 3, in which said powder passages have outlet orifices arranged in a ring surrounding the outlet orifices of said preheat passages and. angularly spaced. therebetween.

I 5. Blowpipe apparatus comprising a nozzle havinga longitudinal oxygen passage and agroup. of preheat passages surrounding said oxygen passage, and an annular member surrounding said nozzle and recessed to form an annular ad.- juvant powder distributing chamber surrounding said nozzle and to form a plurality of adjuvant powder passages leading from said distributing chamber with components concurrent with said. oxygen passage and converging to an apex below the outlet end of said nozzle.

6. Blowpipe apparatus comprising a nozzle having a longitudinal oxygen passage and a groupof preheat gas passages surrounding said oxygen passage, and an annular member surrounding said nozzle and machined to form an annular cooling jacket surrounding said nozzle, an annular adjuvant powder chamber surrounding said cooling jacket, and a plurality of adjuvant powder passages leading from said powder chamber with components concurrent with said oxygen pas.- sage and converging to an apex below the outlet end of said nozzle.

7. Blowpipe apparatus comprising a nozzle having a longitudinal oxygen passage and a group of preheat passages surrounding said oxygen passage and an annular structure surrounding said nozzle, one portion of said structure being constructed and arranged to form an annular adjuvant powder inlet chamber surrounding said nozzle and another portion of said structure being constructed and arranged to form an annular adjuvant powder distributing chamber surrounding said nozzle between said inlet chamber and the nozzle outlet end, means forming circumferentially spaced adjuvant powder passages leading from said inlet chamber to said distributing chamber, and means forming a plurality of adj uvant powder discharge passages leading from said distributing chamber with components concurrent with said oxygen passage and converging to an apex below the outlet end of said nozzle.

8. Blowpipe apparatus comprising a nozzle having a longitudinal oxygen passage and a group of preheat gas passages'surrounding said oxygen passage, an inner member surrounding said passage, and an outer annular member surrounding said nozzle, said inner and outer members having cooperating portions forming an annular adjuvant powder distributing chamber surrounding said nozzle, said inner and outer members having mating conical faces between said distributing chamber and the outer end of said nozzle, one of said mating conical faces having elemental grooves formed therein and spaced therearound and cooperating with its mating 'face to form passages for discharging adjuvant powder from said distributing chamber.

9. Blowpipe apparatus comprising a nozzle having a longitudinal oxygen passage and a group of preheat gas passages surrounding said oxygen passage, an inner annular member surrounding said nozzle, an outer cap member surrounding said inner member and forming therewith a pair of longitudinally spaced chambers, means for supplying adjuvant powder to the first of said chambers, and means for distributing adjuvant powder from the first to the second chamber, said members having mating conical faces, one of said conical faces having elemental grooves forming passages for discharging adjuvant powder from said second chamber.

10. An adaptor for supplying adjuvant powder to a blowpipe having a longitudinal oxygen pas sage and. a group of preheat gas passages surrounding said oxygen passage, said adaptor comprising an annular adjuvant powder nozzle, means for mounting said powder nozzle on said blowpipe in position surrounding the blowpipe nozzle, and a conduit outside of said blowpipe for supplying adjuvant powder to said powder nozzle, said powder nozzle having orifice means directed downwardly and inwardly to'project adjuvant powder through the preheat flame oi said blowpipe toward the oxygen jet.

11. In blowpipe apparatus comprising a blowpipe head and a nozzle connected thereto and having a longitudinal oxygen passage and a group of preheat gas passages surrounding said oxygen passage, the improvement which comprises an annular groove in said blowpipe head forming an adjuvant powder inlet chamber, a sleeve surrounding said nozzle and forming a powder distributing chamber, said nozzle having longitudinal grooves formed therein establishing communication from said powder inlet chamber to said powder distributing chamber, said sleeve and nozzle having mating conical faces, the conical face of said nozzle having elemental grooves for discharging powder from said distributing chamber.

12. Blowpipe apparatus comprising a nozzle having a longitudinal oxygen passage and a group of preheat passages surrounding said oxygen passage, an inner body having a central bore receiving said nozzle, an outer member having a central bore receiving said inner body, the upper parts of said bodies having registering portions comprising an annular groove in the one cooperating with an annular surface of the other to form an upper annular adjuvant powder receiving chamber, said bodies having registering annular surfaces below said receiving chamber to form an annular adjuvant powder distributing chamber, said inner body having a conical lower end provided with grooves extending into said distributing chamber, and said outer body having a conical inner surface registering with said grooved conical lower end of said inner body, and means for introducing streams of adjuvant powder at annularly spaced points around said powder receiving chamber to flow through said distributing chamber and out between said conical surfaces.

13. In apparatus for thermochemical removal of material from a body of such material comprising a blowpipe nozzle for directing against said body a stream of material removing oxygen and a preheat envelope surrounding said oxygen stream, the improvement which comprises an annular adjuvant powder nozzle, means for mounting said powder nozzle on said blowpipe in position surrounding the blowpipe nozzle, and a conduit outside of said blowpipe for supplying adjuvant powder to said powder nozzle, said powder nozzle having orifices for directing a plurality of streams of adjuvant powder from outside said preheat flame envelope in converging relation through said preheat flame envelope toward said oxygen stream and having components concurrent with said oxygen stream.

14. A cutting torch having a cutting tip provided with a central high pressure oxygen passage and an annular row of passages for combustible gaseous mixtures, and means for projecting flux powder into the oxygen stream beyond the end of the tip, said means including a sleeve encircling the tip adjacent to the outlet end and provided with passages at an angle to the oxygen passage of the tip.

15. A cutting torch having a cutting tip provided with a central high pressure oxygen passage and an annular row of passages for combustible gaseous mixtures, and means for delivering flux powder to the oxygen stream beyond the end of the tip, said means including a sleeve encircling the end portion of the tip, the body portion of which has its outer surface forming a wall of an annular passage for flux powder terminating in an annular set or converging passages encircling said oxygen passage and spaced between the passages of said first mentioned annular row.

16. A cutting torch having a cutting tip provided with a central high pressure oxygen passage and an annular row of passages for combustible gaseous mixtures, a sleeve encircling said tip, a jacket spaced therefrom to form an annular passage, means for delivering fluxing powder to said annular passage, and means for delivering fiuxing powder from said passage in streams converging beyond the end of the tip.

17. A method of cutting stainless steel or the like, which includes projecting a stream of material-removing oxygen against the part to be cut, projecting an annular row of flames against the part to be out and around the materialremoving oxygen stream, and projecting an annular row of streams of flux powder between the flames of said annular row, and into said oxygen stream in free space at an angle thereto.

DAVID H. FLEMING, J R.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 968,350 Harrison Aug. 23, 1910 1,247,791 Carlson Nov. 27, 1917 1,412,656 Jenkins Apr. 11, 1922 1,519,639 Simmons Dec. 16, 1924 1,775,911 Nagel Sept. 16, 1930 1,852,649 Gurney Apr. 5, 1932 1,872,409 Coberly Aug. 16, 1932 1,926,438 Fausek et al Sept. 12, 1933 2,184,561 Babcook et al Dec. 29, 1939 2,205,890 Nicholson et al. June 25, 1940 2,209,682 Walker July 30, 1940 2,210,403 Skinner 1 Aug. 6, 1940 2,224,171 Van Triest Dec. 10, 1940 2,286,192 Aitchison et al June 16, 1942 2,286,591 Van Triest June 16, 1942 2,366,787 Hoffman Jan. 9, 1945 2,367,316 Skinner Jan. 16, 1945 2,415,815 Deming M Feb. 18, 1947 2,444,900 Meincke et a1. July 6, 1948 2,451,422 Wagner Got. 12, 1948 FOREIGN PATENTS Number Country Date 64,126 Australia Feb. 19, 1926 198,419 Great Britain May 28, 1923 549,781 Germany May 2, 1932 OTHER REFERENCES Metals Handbook, 1939, published by American Soc. for Metals, Cleveland, Ohio, pages 927, 928 and 930-935 (particularly pages 933 and 934). (Copy in Scientific Library.)

Oxy-Acetylene Cutting, 1943, pub. by Linde Air Products Co., New York city, pages 437-439, inclusive. (Copy in Scientific Library.)

Claims (1)

1. APPARATUS FOR THERMOCHEMICAL REMOVAL OF MATERIAL FROM A BODY OF SUCH MATERIAL WHICH COMPRISES MEANS FOR DIRECTING AGAINST SAID BODY A STREAM OF MATERIAL-REMOVING OXYGEN AND A PREHEAT FLAME ENVELOPE SURROUNDING SAID OXYGEN STREAM, AND MEANS FOR DIRECTING A PLURALITY OF STREAMS OF ADJUVANT POWDER FROM ORIFICES EQUALLY SPACED AROUND AND OUTSIDE SAID PREHEAT FLAME ENVELOPE IN CONVERGING RELATION THROUGH SAID PREHEAT FLAME ENVELOPE TOWARD SAID OXYGEN STREAM WITH COMPONENTS CONCURRENT WITH SAID OXYGEN STREAM.

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