DE9004539U1 - Double pipe - Google Patents

Description

PATENT APPLICATIONS HEMMERICH ■ MUjJ-EH.-* GROSSE · POLLMEIER · MEY - VALENTIN - 1 -

23 364 h-ni 30-03-1990

W. Senk, D"5465 Erpel

S double pipe

The invention relates to a double pipe consisting of an inner and a jacket pipe surrounding it, as well as radial, knob-shaped spacer elements arranged between the inner wall of the edged pipe and the outer wall of the inner pipe. Double pipes of this type are known in a wide variety of designs; they are used for the transport, in particular of liquids of different nature or temperature, possibly in countercurrent, such as the flow and return liquid of heating systems or similar facilities.

The particular advantage of such double pipes is that instead of two separate pipes, only one pipe needs to be laid, which saves laying work and reduces the space required for laying. A further advantage is the direct heat transfer option between the liquid flowing through the inner pipe and the edged pipe.

However, both the manufacture and the installation of such double pipes are difficult . Since the pipes, both the jacket pipe and the inner pipe, are always manufactured using drawing or pressing processes using dies with a ring cross-section, the attachment of the spacer elements to the pipe walls is

PATENT ATTORNEYS iHEMMEgiCH -'MUlLSR." GROSSE · POLLMElER · MEY ■ VALEf-JTlI-. - 2 -

only possible retrospectively, i.e. only after the pipes have already been completed; a problem that has not yet been solved, or not satisfactorily, due to the large finished lengths and the relatively small diameters of the pipes.

It has therefore already been proposed (DE-GM 88 00 949) to insert the spacer elements in bands made of polymer materials and to place the bands on the outer wall surfaces of the inner pipe, e.g. to wrap them around them and, if necessary, to fasten them there and then to push the jacket pipe over the inner pipe and bands with the spacer elements.

The disadvantages of this design are that the bands with the spacer elements are made of plastic and therefore cannot be connected to the inner pipe without problems if this is made of metal, for example, and that the plastic used can undergo undesirable deformations depending on the type and especially the temperature of the liquid flowing through the pipes, and finally that the mechanical strength of such spacer elements made of plastic is limited.

The invention is based on the object of creating a double ear in which these disadvantages and difficulties are eliminated or avoided.

This task is solved by making the inner pipe and jacket pipe out of metal and the knob-shaped spacer elements out of bulges in the jacket pipe directed towards the inner pipe. The inner pipe and jacket pipe should be made of solderable metals, especially copper, and the inner pipe should be made of a ketal that is softer than that of the man-made pipe.

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The exhaust pipe elements can advantageously have a dome-shaped cross-section and can be offset by 45 to 120° in a common cross-section plane of the casing pipe and, if necessary, arranged in one or more rows running in a thread-like manner to the casing pipe circumference.

piß erf i ndungflgeinMfien double pipes laBeon eich relatively easily produced during the molding process, e.g. by pressing the knob-shaped spacer elements into the casing pipe emerging from a drawing or pressing die. The knob-shaped spacer elements can be introduced in the desired arrangement using appropriate program devices. Problems of thermal deformation and lower mechanical strength of the spacer elements do not occur, since these elements are made of the same material as the casing pipe itself. The spacer elements do not need to be specially fastened, since they form part of the casing pipe.

The inventive proposal to use a material for the inner pipe that is softer than that of the jacket pipe makes it easier to bend the double pipe when it is laid. Unlike with a plastic double pipe, when using the inventive double pipe made of solderable metals, the connections between the pipe ends and each other or with other units can be made easily using conventional techniques.

The invention is explained in more detail using the embodiment shown in the drawing. The drawing shows in

''/&bull;■&pgr;.! &igr;&ngr;-&ngr;,&ngr;&idiagr; rr -ti !M'm:·.*,' h ■ Mu.i.iXf. Mto:,^. pci.&igr; i.-ilifi ¹ ■ ml < ■ .'.al· &igr;.'&tgr;&igr;&igr;-: -

Fig. 1 the radial cross-section of the double pipe and in

Fig. 2 shows a detail of the cross section according to Fig. 1 on an enlarged scale.

As can be seen from Fig. 1, the knob-shaped spacer elements are held in place by radially inward-directed

M__.l 1 1 1 1~ J 1 .!_ &Lgr;_ _ ~ 1 &mdash; \ "Ij

naui.cji.j.uiii.CB J. vjcuxxuci-j The na. J- Leu

with its outer wall surface of the inner tube 2

adjacent tip both tubes at a distance d. When ,

In the example, the bulges la are each around ;

90° offset from each other. However, j

Smaller or larger offset angles can also be selected. Smaller offset angles increase the number of

bulges and thus reduce the passage cross- j

cut, but improve the distance constancy d especially j

for tight bending deformations of the double pipe. \

The bulges should advantageously form a dome-shaped j

cross-section, as indicated in Fig. 2, among others |

This increases the stability of the bulge against the I pressure of the inner tube 2 during tight bending deformation

and further ensures that when introducing the

dents in the outer tube 1 no dangerous transverse |

Sectional narrowing of the wall course of the bulge |

genes arise. §

Claims (6)

PATENT ATTORNEY .&igr;&Pgr;&Lgr;'.&Eacgr;&Mgr;&Ogr;, ■ MUU-tr-. -'GRüSSl · POLLi.U- ■ L &iacgr; 364 h-ni 30.03.1990 W. Senk, D-5465 Erpel Claims 1. Double pipe, consisting of an inner and a jacket pipe surrounding it, as well as between the inner wall of the jacket pipe and the outer wall of the Radial, knob-shaped inner tube f spacer elements, ;: characterized, &iacgr; that inner tube (2) and jacket tube (1) are made of metal and the knob-shaped spacer elements (la) consist of bulges in the casing pipe (1) directed towards the inner pipe (2). E 2. Double pipe according to claim 1, 'L characterized by this. that the inner tube (2) and the jacket tube (1) are made of % solderable metals, especially copper. 3. Double pipe according to claims 1 and/or 2,
characterized, that the inner tube (2) is made of a metal which is softer than that of the jacket tube (1). 4. Double pipe according to claim 1,
characterized, that the bulges (la) have a dome-shaped cross-section. 5. Double pipe according to claim 1.
characterized in that the bulges (la) are arranged offset by 45 to 120° in a common cross-sectional plane of the casing tube (1) . 6. Double pipe according to claim 5, ,*» w* w* w ««&igr; -5 ** ^aji A« c c X V that the bulges (la) are arranged in one or more rows running thread -like to the circumference of the casing tube (1).