US2556786A - Method of thermochemically severing tubular metal members - Google Patents

Description

June 12, 1951 .1. L. ANDERSON 2,556,786

METHOD OF THERMOCHEMICALLY SEVERING TUBULAR METAL MEMBERS Filed May 24, 1947 ATTORNEY J Patented June 12, 1951 METHOD OF THERMOCHEMICALLY SEVER- ING TUBULAR METAL MEHBERS James L. Anderson, Closter, N. J., assignor to Air Reduction Company, Incorporated, a corporation of New York Application May 24, 1947, Serial No. 750,210

4 Claims.

This invention relates to a method of thermochemically severing tubular metal members.

There are times when it is desirable to thermochemically sever tubular metal stock very rapidly even though this may result in a rough and poor quality out, and it is the principal object of the invention to provide a method by which this can be accomplished.

By the use of the method to be herein described rough severing of tubes of practically any diameter can be accomplished thermo-chemically in a matter of seconds.

The improved method, and apparatus suitable for use in carrying it out, are illustrated in the accompanying drawing, in which:

Figure 1 is a side elevation, partly in section, of an annular torch tip which is adapted to sever tubes in accordance with the improved method;

Fig. 2 is a horizontal section taken approximately on the line 2'2 of Fig. 1; and

Fig. 3 is a plan view of a section of tubing thathas been severed by the method of the invention showing the nature of the cut that is produced.

According to the invention a metal tube is thermo-chemically severed with great rapidity by projecting against the tube, while the metal at the cutting Zone is at kindling temperature, a number of cutting-oxygen jets arranged in a circular series extending entirely around the tube and which are directed tangentially toward the tube. The cutting-oxygen jets are preferably directed tangentially with respect to the inner surface of the tube and are so spaced circumferentially of the tube that each jet gouges a cut through the wall of the tube which extends a short distance circumferentially of the tube to the next adjacent jet where it joins and forms a continuation of the cut made by that jet. Thus, in the time that it takes a single jet to gouge through the wall of the tube, the tube is completely severed around its entire circumference by the joint action of all of the oxygen jets. The heating of the tube to kindling temperature may be performed in a furnace or the like before the tube is positioned in the cutting apparatus, but preferably the metal of the tube is heated to kindling temperature by preheating flames directed against the tube at the cutting zone by the same apparatus that directs the cuttingoxygen jets against the tube.

The method can be satisfactorily carried out by the use of an oxy-fuel gas cutting torch having an annular tip structure of the kind shown in the accompanying drawing. In Figs. 1 and 2 the annular tip structure is shown at I0. It is 2 adapted to receive and completely surround a metal tube shown at W in Fig. 1. The annular tip structure may be made up of a number of segmental sections suitably fastened together, but preferably it is a unitary annular ring of the kind illustrated.

As best shown in Fig. 1, the annular tip structure has a number of cutting-oxygen jet passages i 1 arranged in a circular series that extends completely around the tube W. The jet passages H are tangentially disposed with respect to the tube so as to project cutting-oxygen jets tangentially toward the tube, several of such cutting-oxygen jets being represented at [2. The cutting-oxygen is distributed to the jet passages I I by one or more cireumferentially extending distributing chambers formed in the annular tip structure. Preferably two or more such distributing chambers are used depending upon the diameter of the work-piece involved; a larger diameter requiring a greater number of distributing chambers to provide even distribution over a greater circumference. Here shown there are two such chambers, semi-circular in shape and symmetrically arranged at diametrically opposite sides of the annular tip structure, one of such distributing chambers shown at I3, serving to distribute oxygen to one-half of the total number of jet passages H and the second distributing chamber M serving to distribute cutting-oxygen to the remaining half of them. Cutting-oxygen is supplied to the distributing chamber 13 through an inlet pipe l5 and to the distributing chamber l4 through a second inlet pipe I 6. As best shown in Fig. 2, the distributing chamber l3 may be conveniently formed in the annular tip it by providing in one of its side faces a recess ii that extends circumferentially part way around the annular tip and is closed by a plate 88. The distributing chamber i l may be similarly formed in the annular tip by a recess [9 closed by a plate 29. The plates l8 and 20 may be soldered or otherwise fastened to the annular tip. The tangential jet passages l I lead from the distributing chambers thus formed to the inner face ll of the annular tip. The inner face of the annular tip is preferably notched at the inner terminus of each of the jet passages II, as shown at 22, so that the discharge orifice of each of the jet passages will lie in a surface 23 (Fig. 1) that is sub stantially normal to the axis of the jet passage.

'The annular tip structure is also preferably provided with a number of preheat jet passages 24 arranged in a circular series extending entirely around the tube W. These passages may be normal to the surface of the tube and may be fed with a combustible gas mixture such as a mixture of oxygen and acetylene, or other fuel-gas, by means of one or more distributing chambers in the annular tip structure. There are preferably two or more such distributing chambers also depending upon the circumference over which the jets must be uniformly discharged. In the structure illustrated two such chambers are adequate, one being shown at 25 in Fig. 1 for distributing the combustible gas mixture to one-half of the total number of preheat jet passages and the other shown at 23 for distibuting the combustible gas mixture to the other half of them. The two distributing chambers 25 and 26 may be conveniently formed in the annular tip by providing an annular recess 2'! in a side face of the tip (Fig. 2), closing it by a plate 28, and dividing the annular recess into two chambers by means of two plugs 29 and 30 (Fig. l). The preheat jet passages 2 lead from the two distributing chambers thus formed to the inner face 2! of the annular tip. The combustible gas mixture is supplied to the distributing chamber 25 through an inlet pipe 3i, and to the distributing chamber 26 through an inlet pipe 32.

If desired, the torch tip may be cooled by cooling water delivered to the tip through a tube 33 and circulated around the tip in a passage 3d and then discharged through a tube 35. A plug 36 (Fig. 1) closes off the passage 3 3 between the inlet and discharge tubes 33 and 35, thus preventing a short-circuited flow of the cooling water directly from the inlet tube to the discharge tube instead of through the major portion of the cooling passage. The cooling passage 34 may be formed similarly to the gas distributing chambers, namely, by providing a circularly extending recess in one side face of the torch tip closed by a plate Bl (Fig. 2).

In using the apparatus to carry out the method, the tube W is inserted in the central opening of the annular tip and the tube and tip are relatively supported in any suitable way so that the outer surface of the tube is uniformly spaced from the inner face of the tip around the entire circumference of the tube. The metal of the tube is then brought to kindling temperature by the preheating fiames, several of which are represented at 38 in Fig. 1, after which the supply of cuttingoxygen is turned on. ihe cutting-oxygen jets l2, being directed tangentially with respect to the inner surface of the tube W, will each gouge a cut in the wall of the tube which extends a short distance circumferentially of the tube. When the oxygen jets are spaced close enough together circumferentially of the tube the separate cuts made by the oxygen jets will join to produce one continuous cut extending completely around the tube and of sufiicient depth at all points to sever the tube. The particular annular torch tip shown in the drawing is not adjustable and is adapted for cutting tubes having the relative diameter and relative wall thickness shown in Fig. 1, although tubes that are slightly larger or slightly smaller in diameter and thickness can be cut by the same torch tip. If the tube is too small in diameter the tangential angle of the cuttingoxygen jets will not be steep enough to cut the wall of the tube. If the tube is too large the cutting-oxygen jets may tend to pierce holes in the wall of the tube instead of gouging circumferentially extending cuts in it, or the individual cuts may not join to produce a circumferentially continuous cut. It is probably more feasible to use for each size tube a non-adjustable torch tip designed especially for severing that size tube than to use a single adjustable one for severing tubes which vary in diameter and thickness over a wide range since such a, tip would have to have some provision for varying the number and tangential angle of the cutting-oxygen jets. By inclining the cutting-oxygen jet passages more steeply than shown in Fig. 1 the annular tip illustrated in the drawing could be used for severing tubes whose size relative to the annular tip is smaller than depicted in Fig. 1.

The molten slag produced by the cutting operation is blown from the out by the force of the cutting-oxygen jets. To prevent the slag from being blown by the oxygen jets onto opposing surfaces of the annular torch tip and clogging the discharge orifices in such surfaces, the cuttingoxygen jet passages H are preferably inclined with respect to the longitudinal axis of the tip and the tube as shown in Fig. 2 so that the oxygen jets blow the molten slag outside of the region enclosed by the inner face of the torch tip. The preheat passages 24 are preferably inclined in a similar manner so that the preheating flames fed by them will impinge on substantially the same area of the tube that the cutting-oxygen jets impinge on. When the torch tip has cuttingoxygen jet passages inclined as just described, and tangentially disposed as shown in Fig. 1, the cut made in the tube W will appear somewhat as shown in Fig. 8 at C. While the inclination of the cutting-oxygen jets relative to the longitudinal aXis of the tube tends to cause the end portion of each cut to be slightly offset relative to the beginning of the next cut, nevertheless the cuts will join and be continuous if they are wide enough or if there is a flare in the width of the end portion of each cut as depicted in Fig. 3. It will be seen from this figure that the cut is a rough one but in certain severing operations this is immaterial, the important consideration being rapid severance of the tube. The present invention makes it possible to sever a tube in a few seconds regardless of the diameter of the tube, when a torch tip is employed that is designed for use with the size tube being severed.

It will be understood that in the foregoing description, and in the accompanying claims, the characterization of the cutting-oxygen jets as being directed tangentially toward the tube does not mean that the jets are necessarily truly tangent to the outer or inner surface of the tube. While the cutting-oxygen jets are preferably tangent to the inner surface of the tube, or nearly so, so that they will gouge grooves in the tube wall and effect substantially complete severance of the tube when the proper oxygen pressure is employed, they could be at a steeper angle if desired so long as they will not pierce holes in the tube wall at the oxygen pressure employed instead of grooving the tube wall.

I claim:

1. ihe method of therrno-chernically severing cylindrical metal tubes which comprises heating the metal at the cutting zone to kindling temperature and directing against the tube oxygen jets arranged in a series around the tube in fixed relaticn to the tube and directed tangentially toward the tube, the jets being close enough together circumferentially of the tube and directed at such an angle with respect to the tube that without relative movement between the tube and the oxygen jets a circumferentially continuous cut is produced having a depth at all points sufficient to cause substantially complete severance of the tube.

2. The method of thermo-chemically severing cylindrical metal tubes which comprises heating the metal at the cutting zone to kindling temperature and directing against the tube oxygen jets arranged in a series around the tube in fixed relation to the tube and directed tangentially toward the tube and also at an inclination with respect to the longitudinal axis of the tube, the jets being close enough together circumferentially of the tube and directed at such an angle with respect to the tube that without relative movement between the tube and the oxygen jets a circumferentially continuous cut is produced having a depth at all points sufficient to cause substantially complete severance of the tube.

3. The method of thermo-chemically severing cylindrical metal tubes which comprises heating the metal at the cutting zone to kindling temperature and directing against the tube oxygen jets arranged in a series around the tube in fixed relation to the tube and directed tangentially with respect to the inner surface of the tube, the jets being close enough together circumferentially of the tube to produce without relative movement between the tube and the oxygen jets a circumferentially continuous cut having a depth at all points sufficient to cause substantially complete severance of the tube.

4. The method of thermo-chemically severing cylindrical metal tubes which comprises heating the metal at the cutting zone to kindling temperature and directing against the tube oxygen jets 6 arranged in a series around the tube in fixed relation to the tube and directed tangentially with respect to the inner surface of the tube and also atan inclination with respect to the longitudinal axis of the tube, the jets being close enough together circumferentially of the tube to produce without relative movement between the tube and the oxygen jets a circumferentially continuous cut having a depth at all points sufiicient to cause substantially complete severance of the tube.

JAMES L. ANDERSON.

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

UNITED STATES PATENTS Number Name Date 1,352,381 Reynolds Sept. 7, 1920 1,701,388 Remane Feb. 5, 1929 1,723,107 Wildeboer Aug. 6, 1929 1,775,311 Halle Sept. 9, 1930 1,888,385 Jenkins Nov. 22, 1932 2,054,375 Halle Sept. 15, 1936 2,221,788 Doyle Nov. 19, 1940 2,252,320 Hughey Aug. 12, 1941 2,266,208 Jones Dec. 16, 1941 2,284,711 Anderson June 2, 1942 2,347,245 Anderson Apr. 25, 1944 2,417,412 Herbst Mar. 18, 1947 FOREIGN PATENTS Number Country Date 701,786 France Mar. 23, 1931

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