US2380570A

US2380570A - Blowpipe nozzle

Info

Publication number: US2380570A
Application number: US399074A
Authority: US
Inventors: Roger S Babcock
Original assignee: Union Carbide and Carbon Corp
Current assignee: Union Carbide Corp
Priority date: 1941-06-21
Filing date: 1941-06-21
Publication date: 1945-07-31
Anticipated expiration: 1962-07-31

Description

July 31, 1945- R. s. BABCOCK BLOWPIPE NOZZLE Filed June 21, 1941 INVENTOR ROGER S. BABCOCK BY ATTORNEY Patented July 31, 1945 BLOWPIPE NOZZLE Roger S. Babcock, Plainfleld, N. 1., asaignor to Union Carbide and Carbon Corporation, a corporation of New York Application June 21, 1941, Serial No. 399,014

(01. Isa-27.4)

6 Claims.

starting point before the cutting oxygen is applied against such point to start the thermochemical reaction, as well as for locally heating the work during the actual cutting operation.

In the past, it has been customary to provide separate mixers or separate mixing arrangements of the oxygen and acetylene passages for each of the mixed-gas outlet ports'or passages. 'Unless such passages were very accurately dimensioned. the resulting preheating flames had non-uniform chemical characteristics. From a practical standpoint. therefore, known self-mixing nozzles are very difficult and expensive to manufacture and when the cutting oxygen is turned on the I preheat flames are undesirably affected. For example, some of the flames would be carburizing, others neutral. and still others would be oxidizing, in the same nozzle. This is very undesirable because the ferrous metal adjacent the cut is adversely or non-uniformly afiected by the different chemical characteristics of the several preheating flames. Furthermore, in usual cutting operations the nozzles become unevenly heated. or several of the orifices become partially clogged with foreign bodies and the effect of either or both of these conditions various the characteristics of each flame to produce a non-imiform condition.

The main object of this invention, therefore, is to provide a self-mixing cutting nozzle of simple and inexpensive construction having improved and uniform operating characteristics. Another object is to provide a blowpipe nozzle having high flashback resistant properties. is to provide a, very compact combined nozzle and blowpipe of comparatively few and inexpensive parts. Other objects are to provide an im-v proved cutting nozzle for severing steel and o r ferrous metal bodies; to obtain uniform prehet flames without the measure of accuracy previously required; and to produce a nozzle at a cost below that of known nozzles having integral mixers.

A further object- A particular problem solved by the invention is the elimination of an expensive blowpipe with a tube carrying premixed gases to the nozzle and the production of a self-mixing nozzle particu larly adaptable to but not limited to plate edge preparation. The use of a tube for conveying premixed gases is undesirable because of the explosion hazard.

In accordance with the invention there is provided a self-mixing nozzle wherein the preheating gases are mixed by a single mixing device and then distributed equally and uniformly to a plurality of preheating flame ports. The single mixer, acting in conjunction with a suitable distribution chamber, uniformly supplies all of the ports with mixed gas having identical chemical characteristics.

Referring to the drawing:

Fig. 1 is a view mainly in side elevation with parts shown in section of a blowpipe embodying features of the invention;

Fig. 2 is an enlarged view in cross-section of the forward end of the blowpipe taken on line 2-2 of Fig. l;

Fig. 3 is an enlarged view in bottom plan looking into the discharge end of the nozzle;

Figs. 4 and 5 are enlarged fragmentary views in section taken on line 0-6 and line 8 -h, respectively, of Fig. i:

Fig. 6 is a view in side elevation of the inn part of the nozzle;

Fig. 7 is a top plan view of the inner part of the nozzle; and

Fig. 8 is a view in vertical section of the outer partof the nozzle.

In Figs. 1 through 8 of the drawing. there is shown one form of the invention comprising a blowpipe 13 having an oxygen inlet nipple 0 and an acetylene inlet nipple A connected to a valve block I! provided with an oxygen valve II and an acetylene valve i2. Hie valve block I. is also provided with a cutting oxygen valve having a control lever L which is swung toward handle H to open the cutting ongen valve and may be locked in this position by a slide 8 having a a catch is which engages a part of the handle H.

Connected to the corresponding valves in the block I I and extending through the handle H are a cutting oxygen pipe II, a preheating oxygen pipe Ii and an acetylene pipe I. The for- Opposite sides oi the conical opening 2! are connected to the preheating oxygen and acetylene pipes l5 and I8, respectively, by

passages

22 and 24 in the head i1.

Connected to the head H by a nut 4| is a selfmixing cutting nozzle N comprising a generally tubular body of metal, such as copper, the exposed external surface 01' which preferably is chromium plated. The nozzle N consists of an elongated tubular inner core part or internal member 25 telescoped within a casing such as an outer cylindrical part or external member 26.

The inner core part 25 is provided with an axial oxidizing gas passage 21 extending from the inlet end 28 to the outlet end 28 of the nozzle. The one-piece member 25 is shaped at the inlet end 28 to provide an annular seat 80 surrounding the central passage and another annular seat 8| longitudinally and radially spaced therefrom. Between the annular seats 30 and ll the part 25 is provided with a pair of eccentric preheatinggas inlets or recesses." and 33 separated by a pair of lateral seats 84 and 35. The

seats

28 and 3| and

seats

34 and 25, as shown, constitute portions of the lateral surface of a frustum of a cone corresponding to the conical socket 2| in the head il, so that such seats are adapted to ill; and form gas-tight seals with the wall oi the socket 2|, thus preventing any leakage between the oxidizinggas and preheating-gaschambers I5, 32 and 33. Each of the recesses'has a lateral wall extending parallel to the longitudinal axis of the nozzle and a bottom surface. The lateral walls of the two recesses form an included angle with each other which is less than 90 while the bottom surfaces are positioned in the same transof the head l1. Thus, when the nut 4| is screwed home the

nomle parts

25 and 28 and the nozzle N and head H are held in assembled relation.

The inner part 25 of the nozzle N is provided along a zone intermediate of its length with a cylindrical portion 43 of reduced diameter 'opposite a conically tapered socket 44 within the outer part 25 to form therewith an internal annular mixed preheating-gas chamber 45 located between the opposite ends of the nozzle N. The inner part 25 is also provided with a substantiall'y long longitudinal preheating-gas mixing passa e 45 of substantially uniform cross-sectional area from end" to end, which discharges into theannular chamber 45. The inlet end 41 of the preheating-gas mixin passage 48 is spaced from the inlet end 28 of the nozzle N and the nozzle part 25 has one preheating-gas passage 48 connecting the preheating-gas chamber or inlet 38 to the inlet end," of the mixing passage 45, and another preheating-gas passage 49 also connecting the other preheating-gas chamber or inlet 22 t0 the inlet end 41 pi the gas mixingpassage 45. The preheating-gas passage 48 is axially in line with the gas mixing passage 46 and is of substantially smaller cross section, while the preheating gas passage 49 is inclined at an acute angle with respect to the passage 4|. The annular distriouter part 28 and is provided with a plurality of buting chamber surface 42 of the body 25, being of reduced diameter, is offset with respect to the outlet end of the preheating-gas mixing passage 46 whereby, upon the body 25 being separated from the casing 28, a cleaning tool can have ready access either when applied to the outlet end of the preheating-gas mixing passage or when a heating oxygenand acetylene to flow through the pipes l5 and 18 to the head H. In the head "the preheating oxygen flows through the passage 23 to the preheating oxygen inlet 38 of the nozzle N, then through the small passage 48 from which it is discharged into the inlet end 41 oi the preheating gas-mixing passage 45, aspirating acetylene into said inlet end 41 through passage 49 to which it is supplied through acetylene inlet 32 and passage 24. The preheatin oxygen and acetylene are then thoroughly mixed as they flow through the relatively long passage 46, being discharged thereby into the annular chamber or recess 45 which distributes the gas mixture uniformly to the several relatively long outlet passages 5|. The resulting jets of mixed gas issuing from the passages 5| are ignited, forming generally converging preheating flames which may be applied to the ferrous metal work after the valves i I and i2 have been adjusted to obtain the desired type of preheating flame. As the work reaches its ignition temperature, the lever L is depressed to cause cutting oxygen to be supplied to and discharged by the central passage 21 in the nozzle N, the cutting oxygen flowing thereto through the pipe l4 and then through passages 20 and H in the head II. The stream of cutting oxygen discharged by nozzle N thermochemically reacts with the hot work and the cutting operation thereupon is carried out in the usual wellknown manner.

The nozzle of the present invention has a particular advantage over self-mixing nozzles known and used in the past because most of such nozzles include separate mixers or separate mixing arrangements of the oxygen and acetylene passages for each preheat passage in the nozzle. Consequently the preheat flames of such nozzles are not uniform and part 01' the flames are carburizmg, part oi. the flames are neutral and part of the have excellent flashback resistance in addition to uniform preheating-flame properties by virtue of their unique construction, with the result that cutting operations involving preheating may be performed more eiiiciently and effectively than with any known cutting nozzles which have been used in the past for similar operations.

While the invention has been shown in a typ of nozzle adapted to discharge a plurality of gas jets forming flames around the cutting oxygen stream it will be understood that the invention also may be applied to that type of nozzle employing a ring of flame around the cutting oxygen stream.

It will also be understood that the disclosure herein is merely for the purpose of illustration and'that the invention is not limited to cutting nozzles alone, but can be embodied in nozzles for other metal removing operations such, for example, as deseaming and desurfacingg What is claimed is:

1. A blowpipe nozzle comprising a generally tubular body having an axial oxidizing-gas passage extending from the inlet end to the outlet end of the nozzle; said tubular body being provided on its inlet end with a circumferential engaging portion having one annular seat surrounding said oxidizingegas passage, another annular seat axially spaced from said first annular seat and also surrounding said oxidizing gas passage, and a pair of eccentrically arranged preheatinggas inlets at the same transverse level about said portion and between said annular seats, said preheating-gas inlets being angularly separated from each other by laterally disposed seats; said body having a mixed preheating-gas chamber located between the ends of the nozzle, and mixed preheating-gas discharge passage means extending from said chamber to said outlet end of the-noz'-' zle; said body also having a preheating-gas mixing passage discharging into said chamber, with the inlet end of said mixing passage spaced from said preheating-gas inlets: and said body having one preheating-gas passage connecting one preheating-gas inlet to the inlet end of said preheating-gas mixing passage, and another preheatinggas passage connecting the other preheating-gas inlet to said inlet end of the preheating-gas mixing passage, at least one of said preheating-gas passages being inclined with respect to said mix.- ing passage.

2. A blowpipe nozzle as claimed in claim 1, with one preheating-gas passage in axial alignmentwith said preheating-gas mixing passage and opening into the one preheating-gas inlet.

3. A blowpipe nozzle as claimed in claim 1, with the centers of the preheating-gas inlets in a common plane and forming with the longitudinal axis of the nozzle an included angle of less'than 4. In a self-mixing blowpipe nozzle. an elongated body provided with a circumferential engaging portion adiacent the inlet end having a pair of axially spaced conical seat portions, a pair of preheating-gas inlets located in the same transverse plane about said end portion and between the conical seat portions, and lateral seat portions angularly separating said inlets from one another; said body also havinga mixed preheating gas recess located between the opposite ends of the nozzle, and mixed preheating-gas discharge passage means extending from said recess to the outlet end of the nozzle; said body also having a preheating-gas mixing passage discharging into said recess, the inlet end of said preheating-gas mixing passage being spaced from the inlet end of the nozzle; and said body also having one preheating-gas passage connecting one preheatinggas inlet to the inlet end of said preheating-gas mixing passage, and another preheating-gas passage connecting the other preheating-gas inlet to said inlet end of the preheating-gas mixing passage, at least one of said preheating-gas passages being inclined with respect tosaid mixing passage. 5. A self-mixing blowpipe nozzle comprising a casing, and an elongated body detachably telescopable within andcooperable with said casing to form a distributing chamber for mixed preof the preheating-gas inlets, and said body also the latter with the inlet end of said preheating heating-gas and discharge passage means extending from said chamber to the outlet end of the nozzle; said body having a circumferential inlet end portion provided with axially spaced annular.

seat portions, a pair of preheating-gas inlets located in a common plane between said annular seat portions, and a pair of lateral seat portions angularly spacing the inlets from one another, a preheating-gas mixing passage discharging into said chamber, theinlet end of said preheatinggas mixing passage being spaced from said inlet end of the nozzle and in axial alignment with one having one preheating-gas passage in axial alignment with the reheating-gas mixing passage and with the'one preheating-gas inlet for connecting gas mixing passage, and another preheating-gas passage connecting the other preheating-gas recess with the inlet end of said preheating-gas mixing passage andextending at an angle with respect to said one preheating-gas passage, the

distributing chamber surface and discharge passage surface of the body being of reduced diameter and inwardly offset with respect to the outlet end of the preheating-gas mixing passage.

6. A blowpipe nozzle having passasemeans including a gas mixing passage within thenozzle for mixing a combustible gas and a combustionpp rtin as to form a gas mixture which subsequently is discharged from the tip of the nozzle to produce a flame, said nozzle being generally in the shape of a tube the central opening of which constitutes a passage for oxidizing gas to be discharged from the tip adjacent such flame, the

end of said nozzle opposite such tip having ain the same transverse plane. .a gas passage disposed in parallel relation to the'longitudinal axis of the nozzle opening to the "bottom of one of said recesses, and a gas passage disposed in angular relation to such axis opening to the bottom of the "other recess, said gas passages being arranged to conduct the different gases to the inlet end of said gas mixing passage, the lateral walls of said recesses being disposed in planes which are parallel 'tothe longitudinal axis of the nozzle and form an included angle with each other which is less