US2534363A - Blowpipe apparatus - Google Patents

Description

Dec. 19, 1950 E. MEINCKE BLOWPIPE APPARATUS Filed April 21, 1945 2 Sheets-Sheet 1 INVENTOR EDWARD MEINCKE ATTORNEY Patented Dec. 19, 1950 UNITED STATES PATENT OFFICE BLOWPIPE APPARATUS Edward Meincke, Scotch Plains, N. J., assignor to The Linde Air Products Company, a corporation of Ohio Claims.

This invention relates to blowpipe apparatus for thermochemically removing metal by a stream. or jet of oxygen from metal bodies having a composition which resists the normal thermochemical action of a stream or jet of oxygen, such resistance being sufiicient to hinder or substantially prevent such normal removal of metal. Examples of such metal bodies are ferrous metals, such as stainless steels, cast iron, and the like, and non-ferrous metals, such as copper, aluminum, nickel, and various alloys. Such metal bodies are difficult or impossible to cut, deseam, desurface or the like by the normal impingement of a stream of oxygen upon successive portions heated to their ignition temperature, or by heating flames which would provide sufficient heat for the removal of metal from plain carbon steel by melting.

The present invention is particularly applicable to the cutting, deseaming or desurfacing of meta's and alloys which have heretofore resisted such thermochemical operations, and is an improvement upon the invention disclosed and claimed in Patent 2,451,422 of Robert L. Wagner. According to the disclosure of the aforesaid Wagner application, metal is thermochemically removed from a metal body, heretofore resisting such action, by introducing a finely-divided adjuvant material such as iron powder into the zone of actio of the oxygen stream or jet in order toproduce reaction products sufficiently fluid that successive portions of the metal body may be thermochemicaly removed when a relative movement is eifected between the body and the oxygen stream or jet. Preferably, the powdered adjuvant material is carried directly into the reaction zone by the stream or jet of metal-removing oxygen.

It is an object of the present invention to provide an improved apparatus for introducing adjuva-nt material into the stream of metal-removing oxygen. Among other objects of this invention are to provide apparatus for introducing finely-divided. adjuvant material into a stream of metal-removing oxygen in a continuous and uni form manner; to provide such apparatus wherein the finely-divided material is introduced into the oxygen stream in the oxygen blowpipe passage of a blowpipe nozzle; and to provide such apparatus whereby the material is introduced at the most eifective point in the oxygen discharge passage. Still other objects are to provide apparatus including a. feed screw for positively moving said material; to provide means for starting and stopping the flows of oxygen and adjuvant material in a predetermined relation to one another; and to provide other features which will be apparent as the following description proceeds.

In accordance with this invention, oxygen is introduced into the oxygen discharge passage of a blowpipe nozzle through a tube arranged in the passage in spaced relation tothe wall thereof, but terminating at a point spaced from the forward end of the nozzle. Powdered adjuvant material is force fed positively and at a uniform rate into the annular space around the oxygen discharge tube by a feed screw mechanism. As the oxygen stream passes out of the discharge tube and into the relatively larger diameter passage of the blowpipe nozzle, it expands, creating an aspiration effect which draws the adjuvant material from the space around the tube into the oxygen stream. Preferably a plurality of small orifices are provided in the space around the discharge tube for distributing powdered material evenly, and for reducing the possibility of powder flashes. The intimate mixture of oxygen and adjuvant material, upon passing out of the discharge passage of the blowpipe, may be brought into contact with a heated portion of a. metal body to effect thermochemical removal of metal therefrom, as by cutting a kerf therein or by removing a surface layer of metal.

Apparatus constructed in accordance with this invention, is illustrated in the accompanying drawings in which:

Fig. l is an elevational view of the apparatus, parts being broken away and in section;

Fig. 2 is an enlarged longitudinal sectional view of the blowpipe head and nozzle shown in Fig, 1;

Fig. 3 is a longitudinal sectional view of a modified form of nozzle;

Fig. 4 is an elevational View of a powder dispenser, parts being broken away and in section; and

Fig. 5 is a vertical sectional view of a modified form of the apparatus of the invention.

The apparatus illustrated in Figs. 1 and 2 comprises a blowpipe B having a head H to which a nozzle N is secured by a coupling nut II. A central oxygen passage or longitudinal bore 12 in the nozzle N is aligned with a chamber IS, in the head H, which receives powdered adjuvant material from a conduit 14 secured in a bore IS in the head.

The rear end of the chamber I3 is closed by a plug l6 having an Lshaped passage ll registering at one end with a bore l8 having one end of an oxygen conduit 19 fitting therein. In the other end of the passage I! is secured an oxy discharge tube 20, which extends axially forwardly through the chamber 83 and into the rear portion of the passage in spaced relation to the wall of the latter, thus forming an annular powder distributing recess and an annular passage 2! around the tube for the flow of powdered adjuvant material. The front portion or outlet end of the annular passage 2 i' is broken up into a plurality of small ducts by a plurality of fins 22 projecting laterally from the front portion of the tube 29, thus providing for even distribution of a plurality of jets of powder into the central oxygen stream leaving the tube 2% through bore l2, and providing a restriction to prevent a powder backflash past the end of the tube.

A positive and uniform flow of powder from the conduit it into the annular chamber 53-, and through the annular passage 2!, is assured by a short rotatable helical feed screw 23 disposed within the conduit i i and the bore i5. if'he feed screw is carried on one end of a flexible shaft 2d, within the conduit M, which is adapted tobe connected at its opposite end to a suitable motor. With this construction, powder is propelled posi tively and uniformly into and through the annular space surrounding the tube 26, including the chamber i3 and the passage 2i. Powder froin the passage 2i is then aspirated into the expanding central jet or" oxygen leaving the tube and an intimate mixture is formed as the powderladen oxygen gas passes along through the elongated oxygen-powder mixing chamber formed by the passage E2 to the outlet at the end of the nozzle.

The nozzle N also has a plurality of longitudinal passages 25 spaced around bore !2 for a fluid combustible preheating medium, such as an oxyacetylene gas mixture. The outlets of the passages 25 are arranged adjacent to, and pref-erably surrounding, the outlet of the oxygen pas sage l2. A conduit 26 secured in a bore 2'2 in the head I-l delivers the fluid preheating medium to an annular distributing chamber or recess 2:? around the rear end of the nozzle N, and thence to the passages 25.

As shown in Fig. l, the blowpipe B may be fed with acetylene or the like and oxygen, by hoses 29 and til, respectively, projecting from the rear end of the blowpipe' handle 3i. When an oxyacetylene g s mixture is employed for preheating, the mixture may be formed within the handle in a well-known manner, and then delivered to the cond it Valves 29 and on the blowpipe control the flow of preheating acetylene and preheating oxygen respectively to form the desired preheating mixture. A third hose 32, for conducting powderc adjuvant material, establishes communication between the rear end of the blowpipe T2- and the bottom of a hopper or dispenser D. The flexible shaft 2 passes through the hose 32 into the hopper D and is operatively coupled to the shaft or" a small electric motor M mounted above the open top of the hopper D on legs 33, so that rotation of the shaft 2:5 by the motor assists the passage of powder through the hose d actuates the feed screw 23.

The blowpipe I.- has the usual long lever 34 for opening and closing a iner-acting spring-closed valve which is independent of the valves 2% and 3t and controls the flow of the metal-removing stream of oxygen delivered to the nozzle passage 52 from the hose To coordinate the flow of metal-removing oxygen with the how of powder from the annular space 22 into the passage i2, a

small toggle switch 35 in the electricalcircuit of and passedthe motor M is mounted on the side of the handle 5i and is pivotally connected to the lever 34 by a link 3%. With this construction, when the operator depresses the lever 3t to start the flow of oxygen to the passage 12, he simultaneously closes the switch and starts the motor M. Conversely, when he releases the pressure on the lever t l, it is raised by the valve spring (not shown) and the switch 35 is simultaneously opened, thus stopping both the flow of oxygen to the passage 52 and the rotation of the motor M. Of course the fiow of oxygen and the operation of the motor N may be started and stopped in any other pedetermined relation to one another if desired. For example, the arrangement of the switch 35, the link 38, and the lever 3d may be such that the flow of oxygen will start or stop either before or after the motor M is started or stopped. Thus, there is provided a movable operating member common to both the metal-removing oxygen control valve and the powder flow device, vnich operating member is movable to one position to start and maintain the now of metal-removing oxygen and to start and maintain. the flow of adjuvant powder and is movable to another position for stopping the flow of metal-removing oxygen and for stopping the flow of adjuvant powder.

When using th apparatus of Figs. 1 and 2 a portion of the metal body from which metal is to be removed is heated by preheating flames formed by combustion oi'the fluid medium from the passages 25. When the heated portion of the metal body has reached the desired temperature, the lever it is depressed and a jet of oxygen carrying finely-divided adjuvant material is discharged against the metal from the central passage 52 of nozzle N. As soon as the metal-removing action begins, relative movement between the blowpi e B and the work is initiated.

If the metal body had a composition such as that of low carbon steel, which is relatively easily removed b the thermochemical action of the oxygen. stream alone, no adjuvant material would be necessary. However, when the composition of the metal body is that of stainless steel, or the like, the oxygen jet alone merely cools the heated portion without removing any substantial amount of metal. With the latter type of steel, the heating frames are unable to maintain a sufliciently high temperature in the reaction zone and the removal of metal generally stops altogether. A finely-divided adjuvant material, such as iron, steel, or ferromanganese is introduced into the oxygen stream and thence into the reaction zone, whereby a thermochemical action producing intense heat occurs. Under these conditions, a metal-removing action occurs, when a relative movement between the nozzle N and the stainless steel body is effected, which closely approximates that of the removal of metal from a low carbon steel.

Fig. 3 shows a nozzle N similar to that of Fig. 2, but designed to provide a preheating flame of the externally-mixed type. A constant flow of oxygen at a relatively low rate is maintained through the central passage 3?, while acetylene or other fluid fuel passes through the annularly arranged passages 35. An inturned annular deflector flange on the end of the nozzle N extends inwardly across the outlets of the passages in spaced relationthereto,anddeflects theflowing fuel streams inwardly into the central oxy gen stream leaving the passage 3i. The combustible mixtureis thus formed outside the nozzle N,

and may be ignited for preheating a metal body.

When the proper temperature has been reached, the oxygen control lever (not shown) is depressed to increase greatly the flow of oxygen through the central passage ill and simultaneously to start the distribution of powdered adjuvant material into the passage Si, in the manner described above in connection with Figs. 1 and 2.

Fig. 5 shows another embodiment of the invention wherein the nozzle N" is identical to the nozzle N of Fig. 2, and is mounted in a similar manner in a head H. The preheating passages 46 are supplied with combustible fluid, such as an oxy-acetylene mixture, by a conduit 4! secured in a bore 52 in the head H". Powdered adjuvant material is supplied to a chamber 43 in the head H" by a conduit 44 secured in a bore 45 in the head. A closed powder hopper 46, shown in Fig. 4, may constitute the source of powder for the conduit 44. The flow of powder into the conduit 44 is assisted by maintaining a gas pressure above the level of the powder in the hopper 43', as by air, oxygen, or inert gas admitted through a pipe H.

A hollow conveyor or feed screw 48 is arranged in the chamber 43 across the outlet of the bore 45. The screw til has a hollow shaft or sleeve 49 extending rearwardly from the chamber 53 through a bearing 50. The shaft or sleeve is is rotated by a worm 5! carried on a horizontally extending shaft 52, and meshing with a worm gear 53 keyed on the rear portion of the sleeve. The end of the shaft 52 may be coupled either directly or indirectly to any suitable motor. A packing gland 54, is provided between the sleeve 49 and the bearing as to prevent the escape of gas.

An oxygen discharge tube 55 is coupled at its rear end to a supply conduit 55:, and extends forwardly through the hollow conveyor screw 48 into the relatively large diameter central passage El of the nozzle N", in spaced relation to the wall thereof, for discharging an expanding stream of oxygen into the passage 53. A packing gland 58 between the tube 55 and the sleeve 49 prevents the escape of gas.

The operation of the apparatus is much the same as described in connection with Fig. 2. screw t8 positively force feeds powder from the bore 45 into and through the annular passage 59 surrounding the tube 55, while the expanding oxygen stream from the tube aspirates powder into the passage 5'5.

Although the nozzle N" is identical with the nozzle N of Fig. 2, it is evident that an externallymixed fiance type of nozzle, such as shown in 3, may also be used efiectively. Also, although the oxygen discharge tube 55 has no fins, it may be desirable to break down the annular passage 59 into small ducts by using an oxygen discharge tube having fins, as in the blowpipe of Fig. 2.

Although several different embodiments of the apparatus of this invention have been described, it will be understood that various changes in the apparatus can be made and that the principles of this invention are applicable to the removal of metal from metal bodies other than these described and to the use of materials other than those mentioned. In addition, other changes may be made without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. Blowpipe apparatus comprising nozzle means having passage means for discharging gas and powder therefrom; a first conduit for supplying a gas to said passage means; valve means controlling said first conduit; a second conduit communicating with said passage means for supplying finely-divided solid material thereto; a mechanical conveyor arranged for feeding such material from said second conduit into said passage means; an electric motor operatively associated with said conveyor; a motor control switch in circuit with said motor; and a common control means for said valve means and switch whereby the flow of gas through said first conduit, and the operation of said conveyor are started and stopped in a predetermined relation to one another.

2. A blowpipe having a head; a nozzle carried by said head, said nozzle having an oxygen passage therein provided with an outlet, and passage means having at least one outlet adjacent said oxygen passage outlet for discharging a combustible preheating nedium; a gas discharge tube extending into said oxygen passage from the rear end thereof in spaced relation to the wall thereof said head having a powder supply duct in communication with the space in said oxygen passage surrounding said tube; a mechanical powder conveyor in said powder supply duct; and conduits in communication with said passage means and said tube for supplying a preheating medium and oxygen thereto, respectively.

A blowpipe having a head; a nozzle carried by said head, said nozzle having an oxygen passage therein provided With an outlet, and passage means having at least one outlet adjacent said oxygen passage outlet for discharging a combustible preheating medium; said head having a powder supply duct including a chamber aligned with said oxygen passage and a conduit communicating with said chamber for supplying finely-divided material thereto; an oxygen discharge tube passing through said chamber and into said oxygen passage in spaced relation to the Wall thereof; a feed screw in said powder supply duct; and conduits severally in communication with said passage means and said tube for supplying a preheating medium and oxygen thereto, respectively.

4. A blowpipe having a head; a nozzle carried by said head, said nozzle having an oxygen passage therein provided with an outlet, and passage means having at least one outlet adjacent said oxygen passage outlet for discharging a combustible preheating medium; an oxygen discharge tube extending into said oxygen passage from the rear end thereof in spaced relation to the wall thereof; said head having a chamber therein in communication with the space in said passage surrounding tube; said head having therein a conduit communicating with said chamber for supplying finely-divided solid material thereto; a feed screw in said conduit adjacent said cham her; and conduits severally in communication with said passage means and said tube for supplying a preheating medium and oxygen thereto, respectively.

5. A blowpipe in accordance with claim 4, also comprising a drive shaft exten ng rearwardly from said feed screw through said conduit to the outside of said blowpipe.

6. Blowpipe apparatus comprising nozzle means having passage means for delivering oxygen and adjuvant powder to a workpiece; a first conduit for supplying oxygen to said passage means; valve means controlling said first conduit; a second conduit communicating with said passage means for delivering finely-divided solid material =operation of stopped in a predetermined relation to one ansaid bore, combustible gas to combustible gas passages, and adjuvant powder means and said control mechanism whereby the flowof oxygen through said first conduit and the conveyor are started and other.

'7. A metahremoving blowpipe apparatus comprising, in combination, a nozzle having a central longitudinal bore extending therethrough, a plurality or" combustible gas passages extending longitudinally of and spaced apart around said bore,

an annular adjuvant powder passage having a plurality of means at its outlet end for distributingaplurality or" jets of powder into an oxygen stream passed through said bore; a plurality of supply conduits severally supplying oxygen to said plurality of to said annular powder passage; control means for said conduits including a first valve controlling the starting and stopping of oxygen flow throughone of said conduits into said bore, a second valve controlling the flow of combustible gas to said combustible gas passages, and a device controlling the starting and stopping or powder flow through another of said conduits into said powder passage; and a movable operating mem- Iber common to both said first valve and said device and movable to one position for actuating bothsaid first valve and said device to start and 'maintain both the flow of oxygen and the flow of powder. and movable to another position for stopping both the flow of oxygen and the flow of powder.

8. A metal-removing blowpipe apparatus comprising, in combination, a nozzle havinga central longitudinal bore extending therethrough, a plurality of combustible gas passages extending 1ongitudinally of and spaced around said bore, an oxygen discharge tube extending axially into the rear end of said bore and having at least a. portion thereof spaced from the internal surface of said bore to provide an annular powder "passage within said nozzle and around said tube, said tube terminating a sufficient distance behind the outlet end of said bore to provide an elongated oxygen-powder mixing chamber within said nozzle and communicating with said annular powder passage; a blowpipe head secured to the rear end of said nozzle and having annular recess means cooperating with said nozzle to provide, respectively, an annular powder distributing chamber communicating with said annular powder passage and an annular combustible gas distributing chamber communicating with said plurality of combustible gas passages; a rotatable feed screw carried by said head for propelling powder through said powder distributing chamber and said annular powder passage into said elongated oxygen-powder mixing chamber; and a plurality of conduits for severally supplying oxygen to said discharge tube, combustible gas to said annular gas distributing chamber, and powder to said annular powder distributing chamber.

9. A blowpipe'havinga head; anozzle carried bysaid head, said nozzle having an oxygen passage therein provided with an outlet,and passage an openinginto the side of said chamber for supplying powder thereto; a hollow rotatable powder tfeed screw in said chamber extending across said opening for conveying powder from said opening into said oxygen passage; and means for delivering oxygen through said feed screw into said oxygen passage while said feed screw rotates.

10. A blowpipe having a head; a nozzle carried by saidhead, said nozzle having an oxygen passage therein provided with an outlet, and passage means having at least one outlet adjacent said oxygen passage outlet for discharginga combustible preheating medium; said head having a powder supply duct including a chamber aligned with said oxygen passage, and a conduit'having an opening into the side of said chamber 'for supplying powder thereto; a hollow rotatable feed screw in said chamber extending acrosssaid opening, said feed screw including a hollow shaft-extending to the outside of said head means on the outside of said head cooperating with said shaft to rotate said feed screw; and an oxygen injector tube extending from the outside of said head through said feed screw and into said passage in spaced relation to the wall thereof.

EDVZARD MEINCKE.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 346,611 vl'toot Aug,.3, 1886 968,350 Harrison Aug.23,'19l0 1,013,379 Dunn Jan. 2, 1912 1,118,183 Bucknam Nov. 24, .1914 1,307,365 .Kinyon JuneZ l, "1919 1,412,656 Jenkins Apr. 11,1922 1,529,379 Thompson Mar. 10, 1925 1,609,013 "Wulfi Nov. 9, 1926 1,715,584 Viletmore -June 1, 1929 1,757,832 Goebels Mayo, 1930 1,769,191 Wetmore July v1, 1930 1,888,385 Jenkins Nov. 22, 1932 ,910,893 Frisch May 23, 1933 1,959,864 Hartley May 22, 1934 2,113,369 Kohout Oct. 31, 1939 2,181,095 Ness Nov. 21, 1939 2,203,211 Buclcnam June-4, 1940 2,221,325 Van 'Zriest Nov. 19, 1940 2,223,492 Buclsnani Dec, 3, 1940 2,223,896 Mandle Dec. 3, 1940 2,290,295 Scheller July 21, 1942 2,299,399 Reeves Sept. 22, 19 .2 2,369,095 Bucknam et a1 Jan. 26, 1943 2,325,442 VioOm July 2'7, 1943 2,451,422 Wagner Oct. 12,1948

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