EP0050363B1 - Method and device for the manufacture of heat exchanger panels - Google Patents

Abstract

The invention relates to a method and an apparatus for the manufacture of heat exchanger elements. A pair of strips of weldable material e.g. high-grade steel is welded together in such a way that on both sides a longitudinally extending weld seam is formed, said pair of strips between said longitudinally extending weld seam defining a longitudinal channel which extends parallel to the weld seams and which serves for the conduction of heating or cooling agents. At least one of the strips is first provided with at least one longitudinally extending groove and is longitudinally welded to the other strip of the pair of strips in such a way that the groove forms with the part of the other strip covering it a longitudinal channel. A liquid filler material is poured into the longitudinal channel and solidified by cooling to below its freezing point. The pair of strips with the solidified or frozen filler material serving as a supporting core is subsequently shaped by plastic deformation of the walls without cutting in such a way that the longitudinal channel hereby acquires the desired shape and finally the frozen filler material is rethawed and removed from the deformed channel.

Description

The invention relates to a method and a device for producing heat exchanger elements of the type mentioned in the preambles of claims 1, 11 and 14.

Such a method is already known (GB-PS 960 975), according to which heat exchanger elements are produced from strips or sheets of weldable steels by first of all producing such a strip or sheet step by step with beads or recesses which form transverse to the longitudinal direction of the Belt run, are provided by pressing devices and in such a way that the beads do not extend over the entire bandwidth, but leave edge areas of undeformed material at the edges. Subsequently, two tapes deformed without cutting in the crotch press process are combined in pairs to form a pair of tapes in such a way that the edge areas lie one above the other and one against the other, while the beads or depressions and elevations of the two tapes are offset with respect to one another in the longitudinal direction in such a way that the tapes are not in the area of the row of beads abut each other, but form a longitudinal longitudinal channel. The edge regions are then welded, while openings are made at the ends of the longitudinal channels for introducing and discharging the medium which is to flow through the heat exchanger element for cooling or heating. Another advantage of the beads, which could also be referred to as a kind of "transverse folds", in addition to increasing the heat transfer area compared to non-winding longitudinal channels, is that the mechanical strength is improved and the flexibility of the heat exchanger elements transverse to the longitudinal direction is improved.

As a result, this method is superior to other known methods (GB-PS 860 569, US-PS 3 394 573, DE-PS 883 585, DE-OS 2 050 795), in which the longitudinal channel is unwound. In processes for the production of such untwisted longitudinal channels, it is also known (US Pat. No. 3,409,961) to extrude a flowable, self-hardening compound, such as Portland cement, thermosetting synthetic resin or foamable polystyrene, between flat belts, so that this releases a support core for the subsequent band deformation and welding , which remains after the longitudinal channel formation at least as an inner lining and / or reinforcement thereof. The spiral winding of tapes is also already known for the production of heat exchangers (US Pat. No. 4,203,205). In practice, however, the inner band often folds.

A disadvantage of the method mentioned at the outset, however, is that the step-by-step manufacturing process limits the manufacturing speed in terms of production technology.

The invention has for its object to improve this method and the device used to carry out the same with simple means to the effect that at least equally good heat exchanger elements can be produced in terms of their effect, but the production itself can be carried out even easier, faster and better.

The solution to this problem according to the invention is characterized in claims 1, 11 and 14. At least one band of the pair of bands is first provided with at least one longitudinal channel and continuously longitudinally welded to the other band of this pair of bands in such a way that the channel forms a longitudinal channel with the part covering it, in particular also a longitudinal channel, of the other band. Then a liquid filling material is continuously filled into this longitudinal channel and solidified by cooling to below its freezing point. Thereupon, the pair of tapes with the solidified or frozen filling material serving as a support core is subsequently deformed without cutting by plastic deformation of the walls of the longitudinal channel in such a way that the longitudinal channel receives the desired shape or the course of the heat exchanger element. After this final shaping, the frozen contents can be thawed again and completely removed from the tortuous longitudinal channel, which is then available for holding the heating or cooling agent.

In other words, the non-cutting deformation of the weldable strips is divided into two sections, namely the channeling and longitudinal channeling on the one hand and the arrangement of the tortuous course of the longitudinal channels, on the other hand. H. deforming their walls. In the case of this main deformation, in which beads, in particular transverse or oblique to the longitudinal direction of the longitudinal channels, are produced in a staggered arrangement in both bands, and / or the longitudinal channel is brought into a spiral shape, the solidified filling material forms a core for supporting the longitudinal channel walls deforming without cutting of the two tapes. It has been shown that water is particularly suitable as a filling material.

It is already known per se (DE-PS 78 621), for example to fill pipes with sand, resin or low-melting alloys, such as lead, in order to prevent the cross-section from being deformed in an undesired manner, in particular significantly reduced, when the same is bent. Accordingly, it is also known (DD-PS 112 613, US-PS 2 841 866). Fill pipes with water so that they can be bent like solid iron after solidification. Although these manual measures have been in the bending of pipes for years Hundreds are known and used, so far they have not been used in the production of heat exchanger elements as in the invention, but - as stated at the beginning - more complex measures have been taken. This application was probably omitted because the weld seams were expected to burst open due to the crystal growth of the ice.

In addition, it has also been known for a long time to deform pipes and other hollow bodies using liquids, flowable metals, rubber or the like in molds and tools. It is also known in the packaging industry to divide a plastic tube filled with filling material, for example milk, by transverse sealing into, for example, tetrahedral packages.

Finally, it is also not new to deform austenitic steels in the cold, for example, since the accelerated formation of martensite increases stressed parts of the workpiece. However, since such measures are used for purposes other than those of the invention, the fact that they are known does not call the level of the invention into question.

It is a particular advantage of the invention that the entire process and not only the welding of the longitudinal seams, in contrast to the subsequent step process, can be carried out continuously, which offers many advantages both in terms of the speed of the production process and the outlay in terms of apparatus; For example, individual units do not have to be continuously accelerated and braked, which, apart from the high expenditure of energy, also repeatedly leads to vibrations of an undesirable type. It is therefore advisable to carry out the process at a feed or conveying speed of between approximately 1 and 8 m / min, which corresponds approximately to the seam welding speed.

The band-shaped heat exchanger elements can then be wound up or bent into the final form of use at the same speed; it may also be advisable here to leave the contents still in the solidified state and only after this winding, bending or similar shaping to convert them into the liquid aggregate state and to let them flow out of the longitudinal channel system. This bending can take place after the strips have been brought into a sinuous shape or provided with beads or the like bulges as mentioned above. In the context of the invention, however, it is also possible to use the continuous channel forming for the bending process only if the production of heat exchanger elements is desired, the channels of which do not have any “corrugated walls”.

A large number of weldable materials, in particular welding steels including stainless steels, can be used to carry out the method according to the invention. Stainless V2A steel offers special advantages, in which welding is also carried out under water cooling.

Unalloyed steels can also be used; however, care must be taken to ensure that the steels are plastically deformable in the cold, which is necessary for freezing the contents. If water is used, it is advisable to cool it down to around -10 ° C. H. Establish a sufficient distance from the freezing point so that it is avoided that the solidified filling material deformation core liquefies in the course of the non-cutting deformation process to such an extent that it can no longer adequately fulfill its function as a deformation core.

The thickness of the strips, in particular sheets, is preferably between 0.5 and 2.0 mm.

It is particularly advantageous if the pair of belts is filled with the liquid filling material in a downward, in particular sloping downward inclined path, and cooled, because the filling material solidifying in the lower part in a freezing station then forms a plug that closes the cross section of the longitudinal channel. so that the filling material flowing in from above cannot flow downwards, but instead there is always a sufficient liquid column of the filling material above the already solidified filling material.

Liquid nitrogen can be used as the cooling medium.

The winding or meandering or serpentine-like course of the longitudinal channels in the conveying direction behind the freezing station is expediently carried out by means of deformation rollers which have elevations and depressions on the lateral surface, as a result of which the bead-like structures can be impressed into the longitudinal channels. So that the cross-section in the longitudinal direction of the longitudinal channels remains as constant as possible, it is advisable to offset these deformation rollers with respect to their elevations and depressions in such a way that an elevation or bulge is being formed in one band when the other band is straight at the overlapping point an indentation or depression is formed. However, this does not rule out the possibility that those heat exchanger elements can also be produced according to the invention in which large and small cross sections alternate in the longitudinal direction of the longitudinal channels.

As is also shown in the drawing, the shape of the channel-shaped longitudinal channels can take on a wide variety. In addition, it can be expedient to arrange a plurality of longitudinal channels in parallel next to one another in a pair of bands.

The method according to the invention also makes it possible, for example, by changing the shaping rollers, that the type of tortuous course of the longitudinal channels can be formed in such a way that subsequent bending is facilitated. Depending on the direction of the bend, it is then expedient to define the shape of the bead-forming recesses and elevations or "mountains and" valleys on the lateral surface of the one ver dimensioning or designing the shaping roller somewhat differently than on the other shaping roller.

It goes without saying that the method is not limited to the use of rollers as deformation tools, but deformation dies can also be used. If the continuous process is used, such deformation tools, as is already known for example in the packaging industry, would have to be moved with the feed or with the conveying of the pair of belts in contact with the same and, after lifting off, be returned in the opposite direction.

• In der Zeichnung zeigen :
  • Figur 1 eine schematische Seitenansicht (teilweise im Schnitt) einer erfindungsgemäßen Vorrichtung zur Durchführung des erfindungsgemäßen Verfahrens ;
  • Figur 2 die Querschnitte verschiedener Bänderpaare mit unterschiedlichen Längskanal-Querschnitten in schematischer Darstellung ;
  • Figur 3 einen schematischen Querschnitt der Hauptformstation mit zwei am Bänderpaar angreifenden und dieses spanlos verformenden Verformungswalzen ;
  • Figur 4 eine Seitenansicht eines nach dem erfindungsgemäßen Verfahrens hergestellten Wärmetauscherelements ;
  • Figuren 5a und 5b ein Bänderpaar in Frontansicht und Aufsicht ;
  • Figur 6 ein solches Bänderpaar einer anderen Ausbildung in Aufsicht ;
  • Figuren 7a und 7b eine Seitenansicht und eine Aufsicht auf ein spiralartig gebogenes Wärmetauscherelement gemäß der Erfindung ;
  • Figur 8 einen Teil eines geschweißten bzw. verschweißten Bänderpaares, das in die endgültige Anwendungsform gebracht ist, in der die Wände der Längskanäle nicht mit Sicken oder einem gewundenen Verlauf versehen sind ;
  • Figur 9 zeigt eine schematische Seitenansicht einer Vorrichtung gemäß einer zweiten Ausbildung zur Durchführung der Erfindung.

Further embodiments of the invention are claimed in the subclaims and are also explained, at least in part, in the following description of the figures:

• The drawing shows:
  • Figure 1 is a schematic side view (partially in section) of an inventive device for performing the method according to the invention;
  • Figure 2 shows the cross sections of different pairs of bands with different longitudinal channel cross sections in a schematic representation;
  • FIG. 3 shows a schematic cross section of the main forming station with two deformation rollers which engage the pair of belts and deform them without cutting;
  • FIG. 4 shows a side view of a heat exchanger element produced by the method according to the invention;
  • Figures 5a and 5b a pair of tapes in front view and top view;
  • Figure 6 shows such a pair of tapes of another training in supervision;
  • Figures 7a and 7b are a side view and a plan view of a spiral-shaped heat exchanger element according to the invention;
  • FIG. 8 shows a part of a welded or welded pair of tapes which has been brought into the final application form, in which the walls of the longitudinal channels are not provided with beads or a curved course;
  • FIG. 9 shows a schematic side view of a device according to a second embodiment for carrying out the invention.

According to FIG. 1, two flat belts 1 with a belt thickness of, for example, 1 mm are fed via two deflecting rollers 2 to a shaping station 3, in which the two belts 1 are guided through rolling passages 4, which run into the belts 1 in the longitudinal direction of grooves 5 (see in particular FIG 2) shape. The strips 1 provided with such grooves 5 are then brought together up to a roller conveyor 6 in such a way that the strip parts still in the flat state, in particular the strip edges 7, abut one another, while the grooves 5 protrude from one another and form a longitudinal channel 8 extending in the longitudinal direction. Instead of one longitudinal channel 8, a plurality of parallel longitudinal channels 8 can also be provided, in particular according to the exemplary embodiments in FIG. 2. In the welding station 9, the adjacent strip parts, in particular longitudinal edges, are connected to one another by means of connection welding, for which purpose seam welding is particularly recommended. Since such continuously effective welding methods for producing weld seams are known, they are not explained in detail here.

In the welding station 9, it is ensured that the continuous weld seams close off the longitudinal channel or channels of the pair of belts 10 now formed, so that - apart from the front and rear opening - longitudinal channels closed off to the outside are present. Liquid filling material is now introduced into this into the longitudinal channel with the aid of a merely schematically illustrated filling device 11, for example via a tube 12 inserted between the bands 1 and into the relevant longitudinal channel 8 of the pair of bands 10. This flows due to the inclined position of the pair of belts 10 in FIG. 1 to the right downwards and is solidified there in the freezing station 13 in the longitudinal channel 8. The freezing station 13 is supplied in particular with coolants or cooling media which bring the contents, in particular water, to a temperature of, in particular, approximately 10 ° below the freezing point, and water at -10 ° C. Lower temperatures should also be considered. Liquid nitrogen can serve as a cooling medium. The freezing station 13 has a freezing tunnel 14 through which the pair of belts 10 is passed. The solidifying filling prevents the still liquid filling material from flowing out downwards and ensures that, as a result of the inflowing filling material through the filling tube 12, a sufficient liquid column always remains above the already solidified filling material, so that the longitudinal channels continuously flow through them extending deformation core is formed.

In the lower part of the device, a protective channel 15 ensures that the cooled pair of belts 10 remains so cold until it enters the main deformation station 16 that the solidified filling material does not yet soften, but rather does its job as a support or deformation core in the main deformation station 16 can. In the main deformation station 16, deformation rollers 17 act on both sides of the pair of belts 10, which give the longitudinal channel or the parallel longitudinal channels 8 a tortuous course, as is shown even more clearly in FIG.

For this purpose, the lateral surfaces of the shaping rollers 17 have elevations 18 and depressions 19. The two deformation rollers 17 are arranged in such a way that their opposing elevations 18 and depressions 19 are arranged in a staggered arrangement such that, for example, the increase 18 of the lower deformation roller 17 which is most strongly attacking on the pair of belts 10 in FIG 19 of the upper deformation roller 17 faces. As a result, the tortuous course of the longitudinal channels 8 is generated without the cross-section in the longitudinal direction of the same changing significantly.

At a feed rate of 2 m / min, a cross section of the steel of approximately 2.16 cm ² and a cross section of three parallel longitudinal channels 8 according to FIG. 2 c of approximately 5.2 cm ² and a temperature reduction from approximately 20 ° C. to approximately -10 ° C an energy around icing of about 63 kcal / m and an energy requirement of about 7600 kcal / h is required. The width of such a pair of bands 10 according to FIG. 2c is 180 mm with a total width of the longitudinal channels of approximately 4 mm.

As shown in FIG. 2, the cross sections of the channels 5 and the longitudinal channels 8 formed from them can be very different. The type of overlapping flat band regions 7 can also be different, i. H. that band material of a band can also protrude beyond the overlapping band regions of both bands in the region of the sealing seam, as is shown in particular in FIGS. 2d-2g.

In Fig. 4 the wave-like or serpentine-like course of the longitudinal channels is shown in side view and in Fig. 5b it is shown how the two channels 5 are separated by a longitudinal seam region 7 and are delimited on the outside by edge regions 7 likewise connected by means of a longitudinal weld seam. The notches or depressions 20 are produced by the elevations 18 of the deformation rollers 17, as shown in FIG. 3, while the elevations 21 of the pair of belts 10 result from the depressions 19 of the deformation rollers 17. In contrast to the course of the depressions 20, according to FIG. 5b, rotated by 90 ° with respect to the longitudinal direction of the weld seams 7, the notches or depressions 20 run in the diagonal direction in the embodiment of FIG. B. rotated by about 45 ° with respect to the longitudinal direction of the weld seams 7 and the pair of bands 10.

In the conveying direction behind the main deformation station 16, the pair of bands 10 provided with a tortuous course of the longitudinal channels 8 can be bent. According to FIGS. 7a and 7b, a spiral-type heat exchanger element is produced in that a certain longitudinal section of the pair of bands 10 is clamped in the middle and then bent towards the outer ends 10a in such a way that the spiral course shown in FIG. 7b results. The inlet and outlet lines are then connected to the two band ends 10a, so that, for example, a heat medium or coolant can enter on one side, pass through the spiral-shaped heat exchanger units and exit on the other side, as seen in the radial direction. In the center 22 of the spiral, the pair of bands 10 forms an S-shaped course. The connecting lines 23 can be seen even better from FIG. 7a. The arrows indicated in the upper part make it clear that, for example, a coolant enters on the left and right, while the medium to be cooled indicated by the lower arrows passes from bottom to top through the heat exchanger element - between the layers of the pair of belts 10. These layers are kept apart by suitable spacing elements.

The principle of the method according to the invention can also be used with great advantage in an alternative embodiment of the invention according to claim 11. In this embodiment of the invention, the longitudinal channel does not have to be wound in the transverse direction at all, but takes a curved or curved course, as for example according to FIG. 7b, without the elevations and depressions alternating in the longitudinal direction. In other words, the depressions and elevations which follow one another in the longitudinal direction are pressed together so infinitely closely that they now only form a groove running in the longitudinal direction. The pair of bands then represents a kind of tube or “tube” that has the weld seams on both sides of the “longitudinal channel forming the tube. After the liquid filling material has been filled in and allowed to solidify, it forms the same good support core as in the alternative of the invention described in detail at the beginning, so that the pair of strips reinforced inside can be bent by non-cutting deformation. The main advantage of the support core is that the cross-section practically not only does not shrink when bending, but also retains its shape.

Fig. 8 shows part of a pair of ribbons bent in this way and Fig. 9 shows how this can be carried out in practice as an alternative or in combination with the shape of the longitudinally extending or longitudinally adjoining depressions and elevations.

The device according to FIG. 9 has a preforming station of the same type as the preforming station 3 shown in FIG. 1. As far as such details are concerned, reference is made to the training described above. In addition, just as in the same embodiment according to FIG. 1, a welding station for producing a pair of strips 10 welded together is provided. Water or other filling liquid is filled into the longitudinal channel with the aid of the filling tube 12 or the like described above. The pair of belts 10 with the channel filled with liquid is continuously directed into a freezing station 13 ', which in this case consists of a conventional compressor-type cooling unit. The freezing station 13 'can have a length of approximately 10 m. Arranged in the belt running direction after the freezing station is a forming station 16, which can correspond to the forming station 16 shown in FIG. 1 and described there in connection. In this molding station 16 are both sides of the pair of tapes 10 by means of shape or. Forming rolls or rollers are machined, which give the longitudinal channel 8 or the parallel longitudinal channels, as described in detail in FIG. 3, a sinuous or serpentine or serpentine course.

In the tape running direction after this forming station 16 there is a cutting station 25 in the vicinity of the forming station 16 and at a distance from the cutting station 25 there is a final forming station 26 for final shaping. This final shaping station 26 is designed in such a way that it gives the pair of belts 10 a spiral course as shown in FIGS. 7a and 7b. For this purpose, two tables 27, 28 are arranged between the cutting station 25 and the final forming station 26 and also after the final forming station 26, which have a sufficient length, for example between 5 and 10 m, in order to store a sufficient length of the tapes required for forming the spiral . If the tapes are on the table 27, they are well insulated to ensure, even with further cooling, that the support core cannot melt or soften from the contents in the longitudinal channels 8. In the final forming station 26, a pair of rollers 29, 26 are arranged above and below the pair of belts 10 to be wound in a spiral shape. After cutting a sufficient length of strips in the cutting station 25, the coil is easily accomplished by rotating the rollers 29, 30 longitudinally about the center between them and under the support of a pair of counter pressure rollers 31, 32. When the spiral shown in Fig. 7 is completed, the rollers 29, 30 are moved back in the reverse direction.

It should be clarified that with the device according to FIG. 9, both the production of essentially smooth unwinded and also with elevations and depressions, i. H. a winding path provided heat exchanger elements is possible. In the case of the unwound heat exchanger elements, the forming station 16 is deactivated. In addition, it should be clarified that it is also possible to produce elements with tortuous channels that are not bent into a spiral or other curved shape, but are used as essentially elongated or straight elements.

Claims (20)

1. Method for the manufacture of heat exchanger elements such as radiator segments, cooling coils or the like, in which a pair of strips (1) of weldable material, e.g. high-grade steel, is shaped and welded together in such a way that at least two longitudinally extending weld seams (7) spaced apart from each other are formed and at least one longitudinal channel (8) extending parallel to the weld seams and between them, which channel corresponds to the meanderlike or serpentine shape of the heat exchanger element and which serves for the conduction of heating or cooling agents, characterized in that at least one strip (1) of the pair of strips (10) is first provided with a longitudinally extending groove (5) and continuously welded longitudinally to the other strip (1) of the pair of strips (10) in such a way that the groove (5) forms with the part of the other strip (1) covering it a longitudinal channel (8), that then a liquid filler material is continuously poured into this longitudinal channel (8) and subsequently the filler material is continuously conveyed by the pair of strips (10) in a downwardly inclined path to a freezing station (13) and solidified there by continuous cooling to below its freezing point, that this pair of strips (10) with its solidified or frozen filler material serving as a supporting core is then continuously shaped by non-cutting in such a way that the longitudinal channel (8) hereby aquires the element shape, and that finally the frozen filler material or the supporting core is rethawed and removed from the deformed longitudinal channel.

2. Method according to one of the preceding claims, characterized in that the pair of strips (10) during the non-cutting shaping of the longitudinal channel is provided with transversely extending corrugations.

3. Method according to one of the preceding claims 1 or 2, characterized in that the pair of strips (10) during the non-cutting shaping of the longitudinal channel is provided with obliquely extending corrugations.

4. Method according to claim 2 or 3, characterized in that the non-cutting shaping of the longitudinal channel is performed in such a way that the corrugations of one strip (1) of the pair of strips (10) are offset in the longitudinal direction from the corrugations of the other strip (1).

5. Method according to one of the preceding claims, characterized in that the liquid filler material is cooled to at least 10° C below its freezing or solidification point.

6. Method according to one of the preceding claims, characterized in that the pair of strips (10) with the supporting core is bent into its shape of use by means of non-cutting shaping.

7. Method according to claim 6, characterized in that the pair of strips (10) is bent into a spiral shape such that adjacent layers of the pair of strips do not lie adjacent to each other, but can be kept apart from each other by spacers.

8. Method according to claim 6 or 7, characterized in that the pair of strips (10) is bent into a spiral shape such that beginning and end of the longitudinal channel (8) are located at the radially outer sides of the spiral, while the longitudinal channel (8) forms at the spiral-center (22) a transition portion curved approximately in an S-shape.

9. Method according to claim 6, characterized in that the pair of strips (10) is bent into the shape of container walls or parts thereof.

10. Method according to one of claims 6 to 9, characterized in that the frozen or solidified filler material is not rethawed until after bending.

11. Method for the manufacture of heat exchanger elements such as radiator segments, cooling coils, etc., in which a pair of strips of weldable material, e.g. high-grade steel, are welded together in such a way that at least two longitudinally extending weld seams (7) spaced apart from each other are formed and at least one longitudinal channel (8) extending parallel to the weld seams and between them for the conduction of heating or cooling agents, characterized in that at least one strip (1) of the pair of strips (10) is first provided with a longitudinally extending groove (5) and continuously welded longitudinally to the other strip (1) of the pair of strips (10) in such a way that the groove (5) forms with the part of the other strip (1) covering it a longitudinal channel (8), that then a liquid filler material is continuously poured into this longitudinal channel (8) and subsequently the filler material is continuously conveyed by the pair of strips (10) in a downwardly inclined path to a freezing station (13) and solidified there by continuous cooling to below its freezing point, that this pair of strips (10) with its solidified or frozen filler material serving as a supporting core is then continuously shaped by non-cutting in such a way that the longitudinal channel (8) hereby aquires a curved or bent course, and that finally the frozen filler material or the supporting core is rethawed and removed from the curved or bent longitudinal channel.

12. Method according to one of claims 6 to 11, characterized in that the pair of strips (10) is not bent into the shape of use until the shaping of the longitudinal channel (8) in its meanderlike or serpentine form.

13. Method according to one of the claims 6 to 11, characterized in that the pair of strips (10) is bent into an essentially smooth shape of use without previous deformation of the longitudinal channel in a meanderlike shape or like form.

14. Apparatus for carrying out the method according to one or more of the preceding claims, with a shaping station for producing the longitudinal channel (8), with a welding station (9) for welding the weld seams (7) and with a conveying device for conveying the pair of strips (10) between these stations, characterized in that the shaping station includes a continuously efficient preshaping station (3) which shapes the groove(s) (5) in the respective strip (1) and is disposed, in the direction of through-travel of the pair of strips (10), in front of the continously efficient welding station (9), and at least one other continuously efficient shaping station (16, 26) which shapes the serpentine course of the longitudinal channel (8) and/or bends the pair of strips to the shape of use and being disposed, in the direction of throughtravel of the pair of strips (10), both behind the welding station (9) and behind the continously efficient freezing station (13) which solidifies the liquid filler material poured into the longitudinal channel (8) by means of a continuously efficient filler device (11) and which is located below the levels of the continously efficient filler device (11) and the welding station (9).

15. Apparatus according to claim 14, characterized in that the filler device (11) comprises a filler pipe (12) which leads between the strips (1) of the pair of strips (10) concerned as far as a point at which the longitudinal seams (7) are already welded.

16. Apparatus according to claim 14 or 15, characterized in that the freezing station (13) comprises a freezing tunnel (14) through which the pair of strips (10) passes.

17. Apparatus according to one of claims 14 to 16, characterized in that the shaping station (16) comprises two shaping rolls (17) which are provided with recesses (19) and projections (18) at the surfaces and arranged on both sides of the pair of strips (10) in such a way that at any given time a recess (19) of one shaping roll (17) overlaps with a projection (18) of the other shaping roll (17) during aligned action on the longitudinal channel (8).

18. Apparatus according to one of the claims 14 to 17, characterized in that in the passing direction of the pair of strips (10) a cutting station (25) is provided between the freezing station (13) and a shaping station devised as a bending station (26).

19. Apparatus according to claim 18, characterized in that the cutting station (25) is arranged adjacent to the shaping station (16) for providing the meanderlike or sepentine course of the longitudinal channel (8) and arranged between said station and the bending station (26), and that the bending station (26) is arranged at such a distance from the cutting station (25) that the space there between serves as a storage space (27) for storing the strips to be bent.

20. Apparatus according to one of the claims 14 to 19, characterized in that the conveying device conveys the pair of strips (10) at a conveying or advance speed of between 1 and 8 m/min.

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