EP1106729A2 - Cross flow heat exchanger for laundry drier with condenser - Google Patents

Abstract

A cross flow heat exchanger for a condensation washer-drier, comprises numerous flat heat exchanger plates (12) which are arranged in parallel as a packet, and a damp air channel (14) composed of a thermoplastic or heat conducting metal. The heat exchanger plates have numerous slats (32) which run laterally w.r.t the damp air channel. The slats consist of cooling laminae and have an open pocket section.

Description

The invention relates to cross-flow heat exchangers for Condensation clothes dryer in one embodiment, such as they explained in the preamble of claims 1 and 2 and from DE 198 38 525 A1 are known.

Compared to this by a low material requirement, despite the thin film thickness of the heat exchanger plates a large one achieved by the webs or spacers Stiffness and good heat dissipation on the The design, which distinguishes the cooling air side, deals with the Invention with such a further development Cross-flow heat exchanger that one of the Dimensions of the plate pack of the known cross-flow heat exchanger appropriate dimensioning of the Disk package an increase or despite less Dimensions of the same an adequate or the same Can achieve cooling performance.

Such a cross-flow heat exchanger stands out according to the invention by the characterizing features of Claims 1 and 2 respectively.

In the construction according to claim 1, wherein the Humid air duct penetrates the heat exchanger plates the webs on one or both sides of the Heat exchanger plates can be provided, depending on whether this to be oriented in a horizontal or vertical position.

With a vertical installation position, with two-sided The bar arrangement does not collect any condensate in the bars, see above that the web wall parts of the pocket-like cooling fins Form cooling surfaces, which intensive heat dissipation to ensure.

In the case of a horizontal installation position, however, the webs become provide only on the top of the plate so that it stay free of condensate.

In the construction according to claim 2, wherein the Heat exchanger plates are penetrated by the cooling air duct, form the intended spacers on one Plate part shaped pocket-like projections that one located between the heat exchanger plates Wet air duct are open. So they form likewise cooling surfaces, which have an effective heat dissipation to ensure. In this case too, both remain horizontal as well as vertical installation position pocket-like projections free of condensate.

In both heat exchanger designs, this means that Bars or spacers next to a corresponding one Enlargement of the area to be covered by the cooling air Channel surfaces at the same time an effective air swirl.

The efficiency of the heat exchanger according to claim 1 improve significantly by the fact that Moist air duct is formed as a flat tube, whereby one whose pocket-like webs with a horizontal arrangement of Heat exchanger plates expedient only to the upper one Form pipe flat side. In this case, the lower plate side of a heat exchanger plate on the of the heat exchanger plate underneath upwards protruding webs, so that despite the absence of the Bottom of the plate protruding downwards between Heat exchanger plates cooling air channels available and thus the Prerequisites for intensive heat dissipation created are.

The length of the extending across the moist air duct Ridges can be roughly the width of a flat tube trained moist air duct correspond. Is preferred however, a web length that is only a fraction of the Corresponds to the width of the flat tube, the webs in Longitudinal direction of the flat tube expediently on gap are provided offset to each other.

In a further embodiment of this heat exchanger construction it may be advantageous to use the webs at least over one Area of the flat tube wall part to the flow direction of the Cooling air directed obliquely, if necessary still densified in some areas or over the entire area flat tube wall part to each other in a symmetrical Provide inclined arrangement.

Such measures, depending on given installation conditions in Condensation clothes dryers for the cooling air in the Heat exchanger optimal flow control and - distribution or optimal loading of the cooling surface achieve, being characterized by a slightly convex curvature the web longitudinal sides transverse to the flow direction of the Wet air the flow conditions in the cooling air ducts let it improve further.

A reduced dimensioning with the same cooling capacity the heat exchanger plates will be possible, if the upper one and lower duct wall part of the moist air duct transverse to Flow direction of the moist air are formed corrugated and the wavy lines of both pipe wall parts preferably run parallel to each other.

The same effect can also be seen in heat exchangers an education according to claim 2, provided that upper and lower plate parts of their heat exchanger plates preferably in the flow direction of the cooling air to one another are parallel corrugated and the depth of the Corrugated valleys expediently about half the mutual distance between the two plate parts corresponds.

To manufacture the heat exchanger plates or the forming films of heat exchangers according to claims 1 and 2 are different materials, such as plastic or aluminum, as well as various manufacturing processes. If plastic film is used for plate production, see above is this e.g. thermally so that two for example, independent of each other, one each Halves forming plate part arise, which are in each other To bring cover and then to opposite Long sides to be welded tightly, glued or to be pressurized.

It is equally possible that the two plate parts provide plastic films from one piece and by folding the plastic film the two plate parts to coincide with each other and then only along two overlapping longitudinal edge parts with each other by welding, gluing or pressure joining connect.

Finally, a preferred manufacturing method consist of heat exchanger plates in a blow mold molded from an extruded plastic tube.

Suitable for the manufacture of plastic plate parts especially acrylonitrile-butadiene-styrene copolymers (ABS) or Polypropylene, where desired to achieve Cooling capacities or the necessary Thermal conductivity and stability a film thickness between 0.15 mm and 0.50 mm, preferably 0.30 mm, as advantageous has proven.

In the case of using an aluminum foil for the production plate parts or heat exchanger plates a film thickness between 0.14 mm and 0.20 mm, preferably 0.15 mm, the ones to be produced therefrom Plate parts along two opposite one another Edge parts by mutual gluing, folding or Pressure joints are to be connected airtight.

Fig. 1:

eine Stirnansicht eines Wärmetauscherplattenpakets für einen Kreuzstrom-Wärmetauscher gemäß einem ersten Ausführungsbeispiel;

Fig. 2:

eine Teildraufsicht des Wärmetauscherplattenpaketes gemäß Fig. 1;

Fig. 3:

einen Querschnitt des oberen Plattenteils eines ersten Ausführungsbeispieles einer Wärmetauscherplatte für einen Kreuzstrom-Wärmetauscher gemäß einem ersten Ausführungsbeispiel;

Fig. 4:

einen Querschnitt des unteren Plattenteils eines ersten Ausführungsbeispiels einer Wärmetauscherplatte für einen Kreuzstrom-Wärmetauscher gemäß einem ersten Ausführungsbeispiel;

Fig. 5:

einen Querschnitt einer aus den Plattenteilen gemäß den Fig. 3 und 4 gebildeten Wärmetauscherplatte;

Fig. 6:

einen Teillängsschnitt entlang der Linie VI - VI durch die Wärmetauscherplatte gemäß Fig. 5;

Fig. 7:

einen Querschnitt durch eine Kunststofffolie zur Bildung eines zweiten Ausführungsbeispieles einer Wärmetauscherplatte für einen Kreuzstrom-Wärmetauscher gemäß einem ersten Ausführungsbeispiel;

Fig. 8 und 9:

jeweils eine Draufsicht auf weitere Ausführungsbeispiele von Wärmetauscherplatten;

Fig. 10:

eine Darstellung ähnlich Fig. 5 zu Veranschaulichung des Querschnittes einer im Blasverfahren gefertigten Wärmetauscherplatte für einen Kreuzstrom-Wärmetauscher gemäß einem ersten Ausführungsbeispiel;

Fig. 11:

einen Längsschnitt durch ein Wärmetauscherpaket für einen Kreuzstrom-Wärmetauscher gemäß einem weiteren Ausführungsbeispiel;

Fig. 12:

einen Querschnitt des Wärmetauscherpakets gemäß Fig. 11, entlang der Schnittlinie XII-XII in Fig. 11 gesehen; und

Fig. 13:

einen Ausschnitt der Fig. 11, in zu dieser Figur vergrößertem Maßstab.

The drawing illustrates preferred exemplary embodiments of the invention, the heat exchanger plates of the heat exchanger plate packages being made from plastic film. Show it:

Fig. 1:

an end view of a heat exchanger plate package for a cross-flow heat exchanger according to a first embodiment;

Fig. 2:

a partial plan view of the heat exchanger plate package according to FIG. 1;

Fig. 3:

a cross section of the upper plate part of a first embodiment of a heat exchanger plate for a cross-flow heat exchanger according to a first embodiment;

Fig. 4:

a cross section of the lower plate part of a first embodiment of a heat exchanger plate for a cross-flow heat exchanger according to a first embodiment;

Fig. 5:

a cross-section of a heat exchanger plate formed from the plate parts according to Figures 3 and 4.

Fig. 6:

a partial longitudinal section along the line VI - VI through the heat exchanger plate according to FIG. 5;

Fig. 7:

a cross section through a plastic film to form a second embodiment of a heat exchanger plate for a cross-flow heat exchanger according to a first embodiment;

8 and 9:

each a top view of further exemplary embodiments of heat exchanger plates;

Fig. 10:

a representation similar to Figure 5 to illustrate the cross section of a heat exchanger plate made in the blowing process for a cross-flow heat exchanger according to a first embodiment.

Fig. 11:

a longitudinal section through a heat exchanger package for a cross-flow heat exchanger according to a further embodiment;

Fig. 12:

a cross section of the heat exchanger package according to FIG 11, taken along the section line XII-XII in Fig. 11. and

Fig. 13:

a section of Fig. 11, on an enlarged scale to this figure.

The plate package 10 shown in Fig. 1 for a Cross-flow heat exchanger for condensation tumble dryers is, for example, eight individual ones, as a whole designated 12, for example horizontally one above the other stacked heat exchanger plates formed.

These heat exchanger plates 12 each have, for example three moist air channels 14 running parallel to one another on that define flat tubes. Each heat exchanger plate 12 consists of a lower plate part 16 (Fig. 4) and a upper plate part 18 (Fig. 3), which from a corresponding deformed film are formed.

In the present case, it is e.g. a film thermoplastic plastic. It might as well be one Foil made of suitable metal, for example aluminum, for Come into play.

Used as a plastic material for the production of the film preferably ABS, with a film in a thickness of preferably 0.30 mm is thermoformed to the two Manufacture plate parts 16, 18.

The two, each shown in Fig. 5 Form heat exchanger plate 12 forming plate parts 16, 18 complementary moldings, so-called blisters, the brought into register with each other and preferably only along outer longitudinal edge parts 20, 22 by welding be connected in a vapor-tight manner. Along from neighboring Moist air channels 14 are their laterally limiting Channel wall parts 28 preferably by pressing together connected, thereby increasing the stability of the heat exchanger plates 12 is favored.

As an alternative to this, the two plate parts 16 and 18, as shown in FIG. 7, can also be formed by a plastic film preformed in one piece as a blister, the halves of which then
brought to congruence by folding and therefore only have to be welded along two overlapping longitudinal edge parts 30 and 31, for example.

The two duct wall parts 24 and 26 of the flat tubes Forming moist air channels 14 are transverse to Flow direction of the moist air is corrugated, wherein both wavy lines preferably parallel to each other run. This measure creates one accordingly Enlarged surface of the cooling capacity which increases the cooling capacity Channel wall parts 24 and 26.

3 and 5, protrude from the upper Plate part 18 on the outside vertically directed cooling fins 32 from, which is transverse to the longitudinal direction of the respective Extend moist air duct 14. The length of this Web-like cooling fins 32 could be approximately the width of the correspond to each wet air duct 14.

In the example shown, however, these are how can be seen in particular from Fig. 2, across the width each wet air duct 14 preferably in three Individual slats 32 of equal height divided that each other are provided offset.

The cooling fins 32 are, as shown in FIG. 6, through Thermoforming pocket-like, open to the moist air duct 14, molded so that the slat longitudinal wall parts 34 and 36 are at a mutual distance from each other, whereby these are preferably still slightly curved outwards are trained to the flow behavior in the To optimally design cooling channels 42.

By deep drawing the cooling fins 32, these are also rounded end edges 38 and 40 (Fig. 2) provided what has a favorable effect on the flow through cooling air.

With appropriate dimensioning of the cross section corrugated heat exchanger plates 12 and more suitable Arrangement and dimensioning of the pocket-like Cooling fins 32 can thus achieve maximum dehumidification achieve the wet air in the wet air channels 14.

If a metal foil, such as aluminum foil, use finds, the web-like cooling fins 32, in Comparison to those from a plastic film shaped, have a reduced height to prevent tearing to avoid the metal foil.

The cooling air is in through the heat exchanger plate pack 10 in the cooling air ducts 42 (FIG. 6) passed through. These inevitably arise in that the layered on top of each other Heat exchanger plates 12 with their lower plate part 16 each on the web-like cooling fins 32 of the upper one Plate part 18 of those below Rest heat exchanger plate 12 (Fig. 6).

The cooling air flows around the cooling fins 32 and brushes the undulating outer surface of the lower and upper plate part 16 and 18, the configuration the same is designed so that with a minimal height of the Heat exchanger plate package 10 an optimal Dehumidification performance, e.g. 0% residual moisture, is achieved (1: 1 exchanger).

Possible variants of the arrangement of web-like Cooling fins 32 for forming a cooling air channel are shown in 8 and 9.

For the purpose of distributing a from an outlet port 33 of a machine mounted fan flowing airflow can 8 for example by a Blower outlet connection 33, facing, compressed Arrangement of cooling fins 32 in the inflow area a Achieve increase in flow resistance, or the Cooling fins 33 can, as shown in Fig. 9, e.g. symmetrical to the transverse center of the cooling air duct 42 under one Angle be inclined, if necessary with increasing lateral distance from the center of the channel enlarged.

Such an arrangement of Bars 32 or bar groups can be one on the cooling air side significant increase in cooling performance through the optimal Achieve exposure to the cooling surface. It can be so in the case of design-related, unfavorable installation conditions of the heat exchanger in the housing Condensation washer dryer by appropriate choice of for air routing and for swirling the cooling air leading pitch angle and by the number of webs 32 to be inclined compared to parallel directed webs 32 up to 20% more cooling capacity to reach.

The heat exchanger plate pack 10 is, analogously to Construction of DE 198 38 525 A1 cited above, at its both ends in one made of plastic existing holding frame sealed what is using an adhesive, preferably cast resin, can be accomplished.

As an alternative to this, the heat exchanger plate package 10 on both sides against a punched or punched Soft rubber sheets are pressed in the relevant Holding frame is inserted.

Another advantageous way of connecting Heat exchanger plate pack and holding frame can be in it exist, the heat exchanger plates with each end to weld a holding frame.

In contrast to the horizontal one shown in FIG. 1 Arrangement of heat exchanger plates 12, these can also in a vertical arrangement rotated by 90 ° be provided. In this case, both Duct wall parts 24, 26 of the moist air ducts 14 pocket-like, open webs 32 are formed. From the itself then vertically extending webs 32 can be attached to them draining condensate. The one from the double-sided web arrangement resulting enlargement of the Cooling surface of the moist air channels 14 enables another Reduction in the size of the heat exchanger plates 12.

Another embodiment of an inventive Fig. 10 illustrates heat exchanger plate in its Cross-sectional design essentially corresponds to that 3 to 5, but with the Difference that they are rather than by each other plastic films connected in a vapor-tight manner Plastic existing molded body 44 is formed from one piece is made by blowing.

For this purpose, an extrusion process is used Plastic hose with a wall thickness of e.g. ≥ 0.40 mm wall thickness in a thermoplastic state in one Blow mold introduced, in both hose ends squeezed and radially into the cross-sectional shape shown blown. Then the closed ones Hose ends separated from the molded body 44.

This manufacturing method largely enables one scrap-free manufacturing process.

11 to 14 illustrate a plate pack 50 for a cross-flow heat exchanger according to claim 2. Accordingly the cooling air through its heat exchanger plates 52nd passed while the humid air Moist air channels 54 flows between the Heat exchanger plates 52 are present.

The end of the heat exchanger plates 52 is in a holding frame 56 indicated by dash-dotted lines or 58 sealed, which they with their Push through cooling air duct 60.

Upper plate part 62 and lower plate part 64 of the Heat exchanger plates 52 are in the flow direction Cooling air is preferably corrugated parallel to one another trained, whereby a correspondingly enlarged Cooling surface is achieved.

The wave profile is preferably chosen such that the bottom 66 of the wave valleys about halfway up the Cooling air channels 60 is located (see FIG. 13), whereby a correspondingly strong exposure to the corrugated Channel inner surfaces for effective heat dissipation is ensured.

The wave profile can be transverse to the direction of flow Cooling air seen also run asymmetrically, d. i.e., the Rise phase in the direction of flow flatter and the Fall phase steeper. This allows the pressure drop reduce and flow separations on the sloping Avoid page largely.

As can be seen from FIGS. 13 and 14, is in the Wave crests 68 of the lower plate part 64 of the Heat exchanger plates 52 each have a variety of laterally spaced apart, elongated depressions 70 molded in, which is transverse to the longitudinal direction of the Wave crests 68 and up to the division plane a-a Extend heat exchanger plates 52 and to the wet air channel 54 located below each open Make pockets. Are preferably in adjacent Wave crests 68 each two aligned Recesses 70 are provided, whereby relative to FIG. 13 long spacers are formed on which the Troughs of the upper plate part 62 with their base 66 support.

The spacers formed by the recesses 70 thus contribute to the stabilization and stiffening of the preferably from a thin-walled plastic film existing plate parts 62 and 64 as shown in FIG. 13 vertically to the direction of flow of those guided in their channel 60 Cooling air and also form in the interior of the duct Cooling elements extending in the direction of flow.

Analogous to the heat exchanger plates 12 in FIGS. 1 to 10 can the plate parts 62 and 64 molded or in Blow process to be made.

Claims (26)

Cross-flow heat exchanger for condensation tumble dryers, with a multiplicity of flat heat exchanger plates (12) which are stacked as a package (10) at a distance and parallel to one another, each containing at least one moist air duct (14) and made of thermoplastic material or of a thermally conductive metal Foil are formed and have a plurality of these projecting, cooling fins webs (32) extending transversely to the humid air channel (14) and, supported on an adjacent heat exchanger plate (12), form cooling air channels (42), the Heat exchanger plates (12) are fixed to one another in a holding frame at their ends, which have the openings of the moist air duct (14), characterized in that the webs (32) forming the cooling fins are shaped as pockets which are open towards the moist air duct (14). Cross flow heat exchanger for Condensation clothes dryer, with a variety of flat heat exchanger plates (52), which as a package (50) are layered parallel to one another at a distance, define a first channel (54) between them and each consist of two plate parts (62, 64) which by two coincidentally spaced and between them a second channel (60) defining, as well as at two each other opposite edge parts tightly together bonded, thermoplastic plastic films or thermally conductive metal foils are formed, which Heat exchanger plates (52) a variety of Have spacers (70) that collectively an adjacent plate part (62) of Support heat exchanger plates (52) on their, the Having openings of the second channel (60) Front ends mutually in a holding frame (56 or 58) are sealed, thereby characterized in that the heat exchanger plates (52) penetrating second channel (60) for guiding Cooling air and that between the heat exchanger plates (52) existing, first channel (54) for guiding Moist air is used and that the spacers (70) as pockets open to a moist air duct (54) are formed. Cross-flow heat exchanger according to claim 1, characterized characterized in that the at least one Moist air duct (14) is formed by a flat tube and that the pocket-like webs (32) at least on of which a flat tube wall part (26) is formed. Cross-flow heat exchanger according to claim 3, characterized characterized that the length of the one Pipe wall part (26) of the flat tube, pocket-like webs (32) only a fraction the flat tube width is and that the webs (32) in Longitudinal direction of the moist air duct (14) to each other Gap are staggered. Cross-flow heat exchanger according to one of the preceding Claims 1 and 3 and 4, characterized in that the webs (32) on their longitudinal web sides (34, 36) transversely to the flow direction of the moist air to the outside are slightly convex. Cross-flow heat exchanger according to one of the preceding Claims 3 to 5, characterized in that the Web (32) at least on the flat tube wall part an area of the same to the flow direction of the Cooling air is directed obliquely. Cross-flow heat exchanger according to one of the preceding Claims 3 to 6, characterized in that the Crosspieces (32) on the flat tube wall part on the upstream side the heat exchanger plates (12) through the cooling air at least in some areas in a compact arrangement are provided. Cross-flow heat exchanger according to claim 6 or 7, characterized in that the obliquely directed Web (32) over the entire flat tube wall part in Flow direction of the cooling air is symmetrical Arrangement are assigned. Cross-flow heat exchanger according to one of the preceding Claims 3 to 8, characterized in that the upper and lower flat tube wall parts (24, 26) of the Flat tube (14) transverse to the flow direction of the Humid air are corrugated and that the Wavy lines of both pipe wall parts (24, 26) to each other run in parallel. Cross-flow heat exchanger according to one of the preceding Claims, characterized in that the Heat exchanger plates (12; 52) each of two mutually congruent and assigned superimposed plate edge parts with each other tightly bonded, formed from plastic films Plate parts (16, 18; 62, 64)) exist. Cross-flow heat exchanger according to claim 10, characterized characterized in that the two plate parts (16, 18; 62, 64) forming plastic films are in one piece and by folding them together to cover one another brought and along two overlapping Longitudinal edge parts together by welding, gluing or printing are connected. Cross-flow heat exchanger according to claim 11, characterized characterized that the two, each one of the flat tube wall parts (24 or 26) forming halves (16, 18; 62, 64) of the plastic film along its foldable connector so gutter-like are formed that when brought into congruence Halves of the plastic film this connector a cross-sectionally U-shaped longitudinal edge piece of Flat tube forms. Cross-flow heat exchanger according to one of the preceding Claims 1 to 9, characterized in that the Heat exchanger plates (12; 52) by a plastic existing blow molded part are shaped. Cross-flow heat exchanger according to one of the preceding Claims 2 to 8, and 10 to 13, characterized characterized that the top and bottom Plate parts (62, 64) of the heat exchanger plates (52) in Flow direction of the cooling air is corrugated are and that the wavy lines of both plate parts (52, 54) run parallel to each other. Cross-flow heat exchanger according to claim 14, characterized characterized that the depth of the troughs about half the distance between the two corresponds to flat plate parts (52, 54). Cross-flow heat exchanger according to one of the preceding Claims 2 to 8 and 10 to 15, characterized characterized that the pocket-like spacers (70) into the wave crests of the wave crests (68) across whose longitudinal direction is molded. Cross-flow heat exchanger according to one of the preceding Claims, characterized in that the plastic for the blown part or the plastic film Acrylonitrile-butadiene-styrene copolymer (ABS) or Polypropylene. Cross-flow heat exchanger according to claim 17, characterized characterized that the trained as a blowing part Heat exchanger plates (12; 52) or the plastic film to form the heat exchanger plates (12; 52) one Wall or film thickness between 0.15 mm and 0.50 mm, preferably 0.30 mm. Cross-flow heat exchanger according to one of the preceding Claims 1 to 9, characterized in that the Metal foil for the production of the plate parts (16, 18; 62, 64) an aluminum foil with a thickness between 0.14 mm and 0.20 mm, preferably 0.15 mm. Cross-flow heat exchanger according to claim 19, characterized characterized that the aluminum foil existing and along two each other opposite edge parts airtight with each other connected plate parts (16, 18; 62, 64) of Heat exchanger plates (12; 52) glued to each other, are folded or press-fitted. Cross-flow heat exchanger according to one of the preceding Claims, characterized in that the Heat exchanger plates (12; 52) arranged horizontally are. Cross-flow heat exchanger according to one of the preceding Claims 1 to 20, characterized in that the Heat exchanger plates (12; 52) arranged vertically are. Cross-flow heat exchanger according to one of the preceding Claims 1 and 3 to 22, characterized in that adjacent moist air channels (14) with each other connecting connecting webs (28) are pressurized. Process for making a plastic existing heat exchanger plate (12; 52) for formation of the heat exchanger plate pack (10; 50) according to one of the preceding claims 10 to 12 and 14 to 18, characterized in that in plastic films by Thermoforming each have a configuration for formation at least one of two halves (24, 26) of one Moist air or cooling air duct (14) and to the Outside of at least one plastic film in Channel longitudinal direction at a distance from each other and towards Moist air duct (14) opening as well as to extending transversely, a plurality of web or pocket-like cooling fins (32) or spacers (70) is formed by deep drawing, that afterwards two foils produced in this way (16, 18; 62, 64), at least one with cooling fins (32) or spacers (70) is equipped in such a way Be brought together to cover theirs Configurations for the moist air duct (14) or Cooling air duct (60) complete and that finally the free longitudinal edge parts (20, 22) of both film halves (16, 18; 62, 64) are tightly connected. A method according to claim 24, characterized in that from the plastic film by thermoforming two connected film halves (16, 18; 62, 64) are manufactured, of which at least one with molded cooling fins (32) or spacers (70) and that by folding the two Film halves (16, 18; 62, 64) along this interconnecting longitudinal edge part for formation of the moist air duct (14) or cooling air duct (60) brought to cover each other and then their superimposed longitudinal edge parts with each other be tightly connected. Process for making a plastic existing heat exchanger plate (12) to form the Heat exchanger plate pack (10) according to one of the preceding claims 13 to 18 and 21 to 23, characterized in that an extruded Plastic hose in a blow mold on both ends squeezed and in these for radial expansion the cross-sectional shape of the heat exchanger plate (12; 52) Compressed air is introduced and that after Completion of the molded body (44) squeezed end pieces separated from this become.

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