DE2623242A1 - METAL PIPE EXPANSION METHOD AND DEVICE - Google Patents

Description

Method and device for Expansion of lie t al ears

The invention relates to a method and a device aura expansion of Iletallrohren = the method according to the invention serves sun radial expansion of a metal pipe and is special useful for expanding a pipe within a concentric one Opening in a metal element with which the pipe is connected to be, the JJr invention also includes an explosive device for use in the method according to the invention.

The process of uniting one metal tube with another iietallelement, for example a larger pipe or a Tubesheet of a heat exchanger by concentrically arranging the holire within an opening in the element and Igniting an explosive charge within the pipe section located in the opening is known. Such a procedure is described, for example, in British patents T 123 836, 1 149 387 and 1 160 761. Depending on the conditions and the length of the explosive charge used, the tube may or may not be expanded into mechanical disengagement with the outer element by a metallurgical bond with the outer element be united. The effectiveness of the connection between the parts can be achieved by arranging projections or depressions on the parts or by attaching rings or other elements between the parts, before detonating the explosive charge still to be improved.

LMB

609883/0288

In the usual method for expanding tubes in tube plates, the explosive charge is arranged at the end of a metal envelope which is coaxially located within the area of the tube that is to be expanded. A Syrian ring-shaped space consisting of the load and the pipe to be expanded is filled with a ring of a material that can transmit the pressure of the explosion, for example polyethylene. 1.Ie is least the explosive charge and the case are designed as a conventional detonator, usually as an electric detonator, and the case usually contains an electric detonator head. While the use of a conventional igniter is most satisfactory for many purposes, it has some disadvantages which limit its usefulness in certain applications, particularly when expanding small diameter pipes. The explosion and the metal particles thrown off by it can, for example, cause surface damage to i, i et all parts outside the pipe section to be expanded, and this is generally undesirable, although it can also be useful if it produces a desired design at a pipe end target. In addition, electrical detonator housings must have an inside diameter that is large enough to accommodate an electrical detonator head in the housing. Therefore, they are not suitable for use in narrow tubes, for example less than 5 mm, unless the sleeve is designed with a relatively large section which enables the ignition head to be arranged outside the tube to be expanded. Another disadvantage of electrical detonators is the risk of premature ignition of the detonator head due to induced or stray current from welding work or other electrical work carried out in the vicinity.

The object of the invention is to provide a method and a device for expanding a metal pipe to create that are applicable to narrow pipes without external

609883/0288

Cause damage.

In the method according to the invention for expanding a metal pipe, a flame-sensitive or fire-sensitive explosive charge is arranged within the section of the pipe which is to be expanded, which explosive charge is suitable for producing the desired expansion; to oil explosive charge, a flame is passed through the bore of an elongated, non-metallic, the flame-transmitting tube by a _ra sch burning substance , which is distributed along the bore, burns, so that a continuous, the flame relaying channel between the rapidly burning substance and the inner wall of the tube remains exposed, whereby the explosive charge is ignited by the flame.

A flame or fire-sensitive explosive charge means in the present context a charge of which at least one Part of a primary ignition charge, which has the property that it burns with certainty until detonation. Ss lies However, it is clear that part of the charge may be a secondary explosive in detonation ratio may be primary explosives. A suitable primary explosive is lead azide.

The tube of the flame transmission device is preferably made of a plastic such as polyethylene, polypropylene, polyvinyl chloride or nylon. In a convenient method, the explosive charge is in one end of the bore of the arranged the flame transmitting tube.

The rapidly burning or deflagrating substance can admittedly comprise granular material that distributes densely enough is to maintain the continuation of the flame, but is preferably a strand of string-like material, the is loosely wrapped in the elongated tube. Preferred cord-like materials include, for example, sextile

609883/0288

yarn or ribbons to which black powder sticks, or thin strands of cordite , because in this process these substances ensure a reliable and even propagation of the'Plar-jEie at speeds of up to 100 liters / second, and the detonation of the explosive charge takes place practically immediately. A cord made of cordite with a diameter of 1.5 to 3 millimeters is expedient. The bore of the flail transmission tube can expediently have a diameter of -; c, ο mm.

The device for igniting the rapidly burning substance can in some cases have an electrical ignition head, as is used in electrical igniters. On the other hand, the dangers associated with electric detonators can be avoided by using a fire mixture which is arranged in the end or near the end of the bore of the cylinder transmission tube, and that the mixture with a burning fuse, for example the one available in Camel Fuse, is ignited. Suitable braids are known in the field of explosives for igniting by means of fuses. They generally consist of powdery oxidizing agents, e.g. potassium nitrate, potassium perchlorate or red lead, and reducing agents, e.g. silicon, sulfur or calcium silicate with a binding agent such as nitrocellulose, rubber or synthetic resin . A particularly suitable mixture comprises on a weight basis the following composition: 30 ', J nitrocellulose, 21.6 ^c / o potassium nitrate, 27 ^ lead-red lead, silicon and 21.1 io 0.3> j diethyl-diphenyl-urea _o

The invention also includes the method of expanding a pipe section in an opening of a tube plate or into a larger pipe, wherein the pipe section into the opening i ⁿ used the larger tube and by the method described above into engagement with the tube plate or the larger pipe is expanded.

609833/0288

The explosive device according to the invention has an elongated, non-metallic flame guide tube with a charge of a flame-sensitive explosive at one end and at the other end contains an ignition device and along its bore a rapidly burning substance is distributed, with a continuous channel continuing the flame is free between the rapidly burning substance and the inner wall of the tube, and wherein the igniter is so arranged is that when ignited it ignites the rapidly burning substance, causing the explosive charge to explode.

In the preferred device v / e is the ignition device on a charge of incendiary mixture, which is preferably from a tubular container mix open end is encased, the solder connected to the flame tube, so the quick Burning substance exposed to the flaj-rae of the brewing mixture is when this is ignited.

in order to precisely attach the explosive charge within the widening area The outer surface is to facilitate the pipe section of the elongated tube releasing the explosive charge preferably with an area facing outwards, for example a step or a collar, which rests at the end of the tube, who inserted the device into it is; ·

The invention is explained in more detail below using an exemplary embodiment in ^{the form of the drawing.}

The figure is a schematic longitudinal section through a device in position to expand the end of a pipe into a pipe plate.

The end of a tube 10 which is to be expanded is arranged in an opening 11 in a tube plate 12. Of the The diameter of the opening is slightly larger than the outer diameter of the pipe 10, which results in a diameter

609 8 83/0288

ο -

play of 0.1 to 0.5 mm results. The opening 11 is for Outer surface 15 of the tube plate 12 expands and forms a frustoconical opening area 14 with a Cone angle of approx. 10.

A plastic pipe 1p closed at one end i "; t with this closed end 16 with a sliding fit without "./eGentliciies game in that section of the end of the Tube 10 arranged to be expanded. To that To facilitate exact attachment of the tube 15 is on the Rohz · an outer collar 17 is formed at the end of the tube 10 and on the outer surface 13 of the tube plate to the plant komnt.

A shock-sensitive explosive charge is arranged in the blind end 16 of the tube 15 and consists of a charge 18 of a secondary explosive, such as pentaerythritol tetranitrate, and a charge 19 of a primary ignition explosive, such as lead azide. The charge may be compacted immediately into end 15, as shown, or it may conveniently be packaged in a separate container and the like. be put into their position.

A thin, metal, tubular capsule 20, which contains a charge of a fire mixture 21, is pushed onto the open end of the tube 15 and fastened with adhesive tape 22. In the capsule 20 and in the G-er.isch 21 a slot 23 is formed, which is used to receive a loop of a fuse, not shown here. Ignition of the mixture 21 is used. A thin strand of cordite 24 is loosely arranged in the bore of the tube 15 and extends from the opening, before it is ignited by the surface of the combustion mixture 21, to a point in the vicinity of the primary ignition charge 19 »- ^; o the flame of the burning cordite ignites the charge 19.

603S83 / 0288

To cause the explosive charge to detonate, a Fuse loops brought into the slot 23 and ignited. When the explosive charge is detonated, the end of the tube 10 is expanded into intimate contact with the tube plate and firmly attached in it. Yienn used an adequate explosive charge is, the "touching surfaces" are welded together.

In the general application of the invention "when fastening tubes in tube plates, such as" in the manufacture of heat exchangers, the tube 10 is also arranged with its other end in an opening of a further tube plate, not shown here. Each tube plate can have several openings for further receiving tubes to be "fastened" therein. When using the method according to the invention, the fuse length can be selected so that the sealed ends are widened either individually, one after the other or at the same time, depending on how it is expedient.

It will be apparent that the method described above can readily be used to join two pipes or to fasten them an end piece, "for example a Hipp ice cream or a nozzle at the end of the tube can be adapted by the tube plate 12 of the arrangement shown here the corresponding element is replaced. Must be in this pail however, the element will normally be supported externally against deformation at the junction.

609883/0288

Claims (1)

Patent a η a υ back e 1.) Procedure for expanding an I. metal pipe, in which in α he. to be expanded at; cut des Iiolires a sum generating the appropriate explosive charge attached and is made to explode, characterized that the explosive charge (18, 19) is flame-sensitive, and that a flame of the explosive charge through a hole in a elongated, non-metallic, for plate guidance serving Holiren (15) by "burning a rapidly burning Substance (24) transferred, which is distributed along the bore in such a way that a continuous, the Flame-propagating channel between the rapidly burning carbon and the inner wall of the tube is free, and that the Explosive charge is ignited by this flame. 2 ♦ Method according to claim 1, characterized in that the flarnnoi'ipfindliehe explosive charge (18, 19) has lead azide. 3. The method according to claim 1 or 2, characterized in that the explosive charge (18, 19) in one Arranged at the end of the bore of the flame transmission tube (15) is. 4. The method according to any one of the preceding claims, characterized in that the rapidly burning substance comprises granular material which is so densely distributed that it maintains the propagation of the flame along the pipe. 5 ο Method according to one of claims 1 to 3, characterized in that the rapidly burning substance has a strand of cord-like material (24) which is loosely encased by the flame transmission tube (15). 609833/0 2 88 6. The method according to claim 5, characterized in that aas schrurähnliche Haterial (24) 'Textile thread or tand on' ./eint to which black powder adheres, 7. The method according to claim 6, characterized in that g e k e η η that the ociinur-like material has one Has strand of aordite (24). S. A method according to claim 7, characterized geke η η seichnet that has liordit strand (24) has a diameter of 1.5 tic Z llillinoter. Method according to one of the preceding claims, characterized g e k e η η ζ e i c Ii net that the]? lai: mienüoertragung sr ear (15) an inside diameter of 3 "to 5 1.IiIIir.ieter Has. 10. The method according to any one of claims 1 to 8, characterized in that the rapidly burning substance (24) is ignited by an electric ignition head. 11. The method according to any one of claims 1 to 9, characterized geke η η ζ eich net, cla.o the rapidly burning substance is ignited by a fire mixture (21), which in the end or in the ITäiie of the 2nd es the bore of the placaaenuassungsrohres ( 15) is arranged, and also the fire geiiisch is healed with a separating fuse. 12 »Proceeds according to one of the preceding claims, characterized by the fact that the Section of the first metal tube into an opening (11) a 2o2ir plate (12) or inserted into a larger I-ear and is widened into engagement with the tube plate or the larger tube. 13o device for expanding a metal pipe with one 60 9883/0288 BATH ORIGINAL explosive charge suitable for generating the possibly urgent expansion, characterized in that the Explosive charge (10, 18) flaninerapfindlicii and at one end an elongated, non-metallic planetary transmission tube (15) is arranged v / elches at its other end has an ignition device (21) and along its bore a rapid abbrennendor Jtof; "(24) bo is distributed that a continuous, the plan Γortpfla.nsen.the channel between the rapidly burning substance and the inner wall of the ear (15) is free, that?> the ignition device (21) is turned on so that it ignites the smoke-burning substance (24) when it is ignited, v; odby the explosive charge (10, 19) explodes and the metal pipe (10) as a result. widened v / ird. 14. The device according to claim 15, characterized in that g e k e η η ξ e, i c h 11 e t that the ignition device has a charge of an Erc.11agemiscL.es (21). 15. The device according to claim 14, characterized in that g e Ic e η η - ζ calibrate η e · t that the Lrandgernisch is surrounded by a tubular container (20) with an open end, which is connected to the plan transfer tube so that the rapidly burning substance (24) is exposed to the plan of the fire mixture (21) when the braidgcnisch is ignited. 16. Apparatus according to claim 14 or 15, characterized in that - ] ·: E 11 η ζ eich η et that the Brar.dneinisch (21) has powdery oxidizing agents and cedating agents, which with a Binders are bound. 7. Apparatus according to claim 16, characterized in that then 3ra.:iäge::iiscii (21) zaliurane nitrate, Red lead and silicon bonded with nitrocellulose. 13. Device according to one of claims 15-17, characterized characterized that the flararian transmission 609883/02 8 8 - 11 tube (15) is made from a synthetic material. 19. The device according to claim 18, characterized in that the Flarrjiienubertragungsrohr (15) from Polyethylene, polypropylene, polyvinylchloride or ITyIon is", 20. Device according to one of claims 13 to 19, characterized marked, do.ß the outer surface of the Flame transmission tube (15) with an outwardly protruding Area (17) is provided, which is to rest on the end of the pipe to be expanded to facilitate the exact attachment The explosive charge is used in relation to the ear to be widened (10). 21. The device according to claim 20, characterized in that the FlaHmer.ubertragungsrohr with the outside a step or a collar (17) is provided. 6,9883/0288 Blank page