NL2018175B1 - Recuperator - Google Patents

Abstract

The invention provides a recuperator comprising a number of adjacent sheets which are connected to each other. Flow channels are formed between adjacent sheets. Each of the sheets is at least partially surrounded by and connected to an associated connecting body at its periphery. Neighboring connecting bodies are connected to each other on at least a part of the circumference of the associated sheets and together form the wall of a housing. Through-flow openings are provided in the wall which are connected to the flow channels for admitting air to the flow channels via the flow openings. Furthermore, the invention provides methods for producing a connecting body and for producing a recuperator.

Description

Netherlands Patent Office © 2018175 © Application number: 2018175 © Application filed: 16/01/2017 © BI PATENT © Int. CL:

F28D 21/00 (2017.01) F28D 9/00 (2017.01) F28F

3/10 (2017.01) F28F 9/00 (2017.01)

(T) Application registered: © Patent holder (s): 26/07/2018 Recair Holding B.V. in Waalwijk. © Request published: - © Inventor (s): Marinus Henricus Johannes van Kasteren © Patent granted: in WAALWIJK. 26/07/2018 © Patent issued: © Authorized representative: 03/08/2018 ir. J.M.G. Dohmen et al. In Eindhoven.

© Recuperator © The invention provides a recuperator comprising a number of adjacent sheets which are connected to each other. Flow channels are formed between adjacent sheets, each of the sheets being surrounded at least in part by and connected to an associated connecting body. Neighboring connecting bodies are connected to each other on at least a part of the circumference of the associated sheets and together form the wall of a housing. Through-flow openings are provided in the wall which are connected to the flow channels for admitting air to the flow channels via the flow openings. Furthermore, the invention provides methods for producing a connecting body and for producing a recuperator.

NL Bl 2018175

This patent has been granted regardless of the attached result of the research into the state of the art and written opinion. The patent corresponds to the documents originally submitted.

Short indication: Recuperator

Description

The invention relates to a recuperator comprising a number of adjacent sheets extending parallel to each other, which sheets are connected to each other on at least a part of their circumference and wherein flow channels are formed between adjacent sheets.

The Dutch publication NL 1030270 describes a method for manufacturing a heat exchanger with sheets extending parallel to each other. Sheets are stacked on top of each other, after which neighboring sheets are connected to each other at their circumference by chemical welding, using a solvent to partially dissolve the material of the sheets at the circumference thereof. Subsequently, in practice, a housing is provided around the stack of sheets thus welded together, which housing is connected to the stack by gluing. The housing ensures that the dimensions of the heat exchangers produced in this way are relatively constant and that the heat exchangers are therefore interchangeable, for example. In addition, the housing on the stack provides mechanical protection and the ability to connect the heat exchanger to air supply and discharge lines that communicate with the flow channels between the sheets.

For the automated execution of the known method highly specialized assembly devices are required. The invention has for its object to provide a recuperator according to the preamble which can be manufactured in a relatively easily automated manner. To this end, each of the sheets at the periphery thereof is at least partially surrounded by and connected to an associated connecting body, wherein adjacent connecting bodies at at least a part of the circumference of the associated sheets are connected to each other and together form the wall of a housing wherein flow openings are provided in the wall which are connected to the flow channels for admitting air to the flow channels via the flow openings. The use of a connecting body makes it superfluous to connect sheets directly, for example by gluing or welding, such as in particular chemical welding or ultrasonic welding. Chemical welding and gluing have the important disadvantage that solvents are or may be necessary that are dangerous and therefore require additional safety measures. Neighboring sheets of the recuperator according to the invention are connected to each other during the manufacture of the recuperator via the connecting bodies associated with the respective sheets. The interconnected connecting bodies further fulfill the function of a housing in the sense that they protect the sheets. The connecting bodies can further be designed to make connection to supply and discharge pipes easily executable. It is therefore not necessary to use separate enclosures that are custom made in advance. This also brings with it the advantage that it is rather cost-effective to produce recuperators in smaller numbers, for example specifically for a specific application or on customer specification.

In one embodiment the flow-through opening is formed between adjacent connecting bodies. By connecting the neighboring connecting bodies together, the flow openings are created in such a variant, which makes a relatively simple embodiment of the connecting bodies possible.

Alternatively, it is also possible that the flow openings are formed in, instead of between, connecting bodies.

A mutually correct positioning of the connecting bodies and hence of the sheets can easily be obtained if the adjacent connecting bodies are provided on opposite sides with projecting parts and with recesses, the shapes of the projecting parts and of the recesses connecting to each other for interconnecting the connecting bodies. The projecting parts and the recesses can also be utilized to realize an, airtight or at least substantially airtight, clamp connection or snap connection between the adjacent connecting bodies.

The assembly of the connecting bodies with associated sheets can be facilitated if the projecting parts and / or the recesses have a tapered shape or at least partly a tapered shape so that a self-searching positioning can be realized.

A fast and reliable connection between neighboring connecting bodies can be obtained if the neighboring connecting bodies are clampingly connected to each other. Such a connection makes the use of welding or gluing of neighboring connecting bodies superfluous, although it is also possible to combine the clamping connection with a welding or glue connection in order to increase the reliability of the connection. The use in the case of such a combination of ultrasonic welding entails the advantage that no solvents then have to be used in any case.

The connection between two adjacent connecting bodies can be airtight with a high degree of reliability if the neighboring connecting bodies are connected to each other by a press fit.

A practical embodiment, at least during assembly and possible disassembly, can be obtained if adjacent connecting bodies are connected to each other by means of a snap connection.

For effecting an at least substantially airtight connection between adjacent connecting bodies, it can be advantageous if the recuperator between adjacent connecting bodies is provided with a sealing body at the location of the mutual connection, wherein it is, in particular from the viewpoint of striving for a simple assembly, it is further preferred that the sealing body is connected to one of the two adjacent connecting bodies.

The invention lends itself, inter alia, to recuperators of the membrane type. The sheets of such recuperators are suitable for exchanging moisture. The material of such sheets does not lend itself well to being welded. The use of glue for interconnecting membrane sheets entails the drawback that this is a step that is difficult to control and therefore also expensive, in particular if recuperators are produced in larger numbers and that, depending on the type of glue used, harmful solvents are also used. Therefore, at least a portion of the sheets of a recuperator according to the invention can advantageously be permeable to moisture.

The recuperator can advantageously be provided with sheets which are all provided with a profile. The connecting bodies can thereby contribute to a correct mutual positioning of the sheets, more specifically of the profiles thereof, because the sheets can behave relatively rigidly due to the connection with the connecting bodies.

Alternatively, the invention also lends itself to a more traditional way in which sheets can be provided in a recuperator, namely wherein the neighboring sheets are alternately flat and have a profile.

Precisely because the invention makes it superfluous to connect adjacent sheets directly to each other, the recuperator according to the invention can also be advantageously used if sheets are made of different materials, for example if neighboring sheets are made alternately from different materials.

An advantageous application of the invention can be in the case of recuperators in which a part of the number of sheets is made of a moisture-permeable material and the other part of the number of sheets is made of a material that does not allow moisture to pass through. Such materials are difficult to combine with traditional recuperators.

To obtain a good connection between a connecting body and an associated sheet, it may be preferable in the case that sheets of different materials are used if the connecting bodies are made of different materials. A fixed combination of the material of the connecting body and the material of the associated sheet is then formed.

From a structural point of view, it can be advantageous if each of the sheets is at least largely, as well as completely, surrounded by an associated connecting body.

In particular if there are relatively large production numbers, it may be preferable for the connecting bodies to be injection molded.

According to a possible embodiment, the sheets have a hexagonal shape and the circumference of the housing is bar-shaped. The hexagonal shape of the sheets is often preferred in the design of a recuperator. The beam shape of the housing facilitates the connection of other components such as, in particular, air ducts to the recuperator. The invention offers the possibility of giving the housing a beam-shaped circumference in a simple manner, namely by adapting the design of the connecting bodies thereto. Bar-shaped is understood to mean all shapes in which there are six main planes that are perpendicular to each other. The shape of a cube therefore also falls under the definition of a beam shape.

By at least partially positioning the peripheral edge of the sheet belonging to the connecting body in the mold during injection molding, the connection between the sheet and the connecting body can be realized directly during injection molding. Within the latter framework, it can be advantageous if the sheets along the first part of the circumference of the connecting bodies are sprayed on by the material of the connecting bodies during the injection molding of the connecting bodies on the circumference of the sheets. Therefore, the invention also relates to a method for producing a connecting body for use in a recuperator according to the invention, the method comprising the steps of closing a mold creating a mold cavity and a sheet on at least a portion of the circumference of the sheet is positioned in the mold cavity by injection molding the connecting body in the mold, the sheet in the mold cavity being sprayed on by the material of the connecting body at at least a part of the peripheral edge of the sheet.

After or even during the solidification of the material being injection molded to form the connecting body, it is also possible to injection-mold another material to form a sealing body against the connecting body. This can be done by temporarily enlarging the mold cavity after admitting the liquid injection molded material into the mold cavity and before the mold is opened to remove the connecting body from the mold and locally injection-molding the other material into that enlarged part of the mold cavity.

The invention further provides a method for producing a recuperator according to the invention, the method comprising the steps of providing circumferential connecting bodies each with a sheet connected to the associated connecting body and extending on the inside of the circumferential connecting body, joining connecting bodies together such that flow channels arise between adjacent sheets associated with adjacent connecting bodies.

It may be preferred here that neighboring connecting bodies are connected to each other by clamping neighboring connecting bodies to each other, preferably by means of a press fit.

The invention will be further elucidated on the basis of the description of a possible embodiment of a recuperator according to the invention with reference to the following figures which are not to scale:

Figure 1 shows a perspective view in partial exploded view of a recuperator according to the invention;

Figures 2a and 2b show in perspective top view and in bottom perspective view a layer of the recuperator according to figure 1;

Figures 3a to 3f show diagrammatically in vertical cross-section a part of the layer as shown in figures 2a and 2b during successive steps of its production process;

Figures 4a to 4e show optional subsequent steps after the step according to Figure 3d;

Figure 5 shows a perspective view of an alternative embodiment of a recuperator according to the invention;

Figures 6a and 6b show in perspective top view two layers of the recuperator according to figure 5;

Figure 7 shows in perspective view in partial exploded view the recuperator according to figure 5 including connecting parts as these can be used in practice.

Figure 1 shows a recuperator according to the invention designed as heat exchanger 1. Twelve layers 2 of heat exchanger 1 are shown, each of the layers 2 comprising a circular, hexagonal connecting body 3. The free passage on the inside of the circular shape of each connecting body 3 is closed off by a sheet 4 as shown in the figures 2a and 2b. The connecting bodies 3 are alternately provided in two different geometries 3a, 3b. Connecting body 3b is equal to a version of connecting body 3a mirrored in vertical mirror surface 8. The connecting bodies 3a, 3b are alternately connected to each other in a manner that will be further explained.

The interconnected connecting bodies 3a, 3b together form the wall of a housing with six standing wall parts on the respective hexagonal sides 10a to 10f of heat exchanger 1. Insofar as previous use is made of concepts such as "standing" or "vertical" is meant on the situation in the state of use of the relevant heat exchanger.

In this example, the sheets 4 associated with the different connecting bodies 3, or with the different layers 2, are made of the same material, namely polystyrene (PS) that is not permeable to moisture. Alternatively, however, it is also possible that all sheets 4 are made from a different material, typically from a plastic such as, for example, high-density polyethylene (HDPE), but also, for example, from a metal such as aluminum. The material used of the sheets 4 may further be permeable to moisture. It is also possible that the sheets 4 are made within a heat exchanger, in that case preferably alternately, from different materials, for example selected from the materials as mentioned above. The geometries of the sheets 4 differ from each other between profiled sheets 4a and planes of sheets 4b. To the extent that the distinction is not important, reference numeral 4 is used in this document for sheets 4a and 4b, so whether they are flat sheets or profiled sheets. To the extent that the distinction is important, the reference numerals 2a and 2b are used for layers with a profiled sheet 4a and a flat sheet 4b, respectively. Figures 1 to 2b do not show the profiling of sheets 4a for the sake of clarity. Incidentally, it is also conceivable within the scope of the invention that all sheets 4 are profiled or that all sheets 4 are flat. The thickness of the sheets 4 can typically vary between 0.05 mm and 2 mm. The width of the flow channels can correspond to the period of a profile or half of it, but also to a number of periods of a profile and even to the dimension of the sheet viewed transversely of the flow direction.

Although twelve layers 2 are shown in Figure 1, the number of layers 2 of a heat exchanger 1 can actually be higher, for example 100 layers, but the number of layers 2 can also be lower, for example 8 layers. The heat exchanger has a sealing cover body 41 at the top of the stack of layers 2 and a sealing bottom body 42 at the bottom of the stack of layers 2. For the sake of clarity, the height of the layers 2 is shown higher in the figures than that the height is in reality. It is indicated as an indication that in reality the distance between two diametrically opposed points of the hexagonal shape, which points are otherwise truncated, of the connecting bodies 3 is typically between 5 cm and 100 cm while the height of the layers 2 is typical located between 2 mm and 20 mm.

Air channels are formed between adjacent sheets 4. During operation of the heat exchanger 1, energy is exchanged between air that flows in opposite directions through adjacent flow channels. For admitting air into flow channels, inflow openings 11a have been formed between two adjacent connecting bodies 3a, 3b, more specifically at the hexagonal side 10a of heat exchanger 1. Outflow openings 12a are formed on the opposite side at the location of the hexagonal side 10d (not visible because of the perspective in Figure 1). Each of the inflow openings 11a is connected via the flow channels between two adjacent sheets 4 with an associated outflow opening 12a. For admitting oppositely flowing air into flow channels, inflow openings 11b are formed between two adjacent connecting bodies 3b, 3a, more specifically at the location of the hexagonal side 10th (not visible because of the perspective in Figure 1). Outflow openings 12b are formed between adjacent connecting bodies 3b, 3a on the hexagonal side 10b, each of the inflow openings 11b communicating via a flow channel between two adjacent sheets 4 with an associated outflow opening 12b. The flow channels are formed in the rectangular region between the two opposite hexagonal sides 10c and 10f. The triangular areas between said rectangular area and the hexagonal sides 10a, 10b on the one hand or the hexagonal sides 10d, 10e on the other hand are collection areas in which either the air that flows in through an inflow opening 11a, 11b is distributed over the flow channels between two sheets 4 before the air flows into these flow channels, or supplies the air that flows out of the flow channels between two sheets 4 to an outflow opening 12a, 12b.

The layers 2 are connected to each other via the connecting bodies 3 by means of a clamp connection. To this end, the connecting bodies 3 are each provided with a hexagonal part 14 with a circumferential rib 15 at the top thereof and in which hexagonal part 14 at the underside a circumferential groove 16 is provided. The circumferential rib 15 is interrupted for connecting bodies 3a at the hexagonal sides 10a and 10d to form an inflow opening 11a and an outflow opening 12a, respectively. The circumferential rib 15 is interrupted for connecting bodies 3b at the location of the hexagonal sides 10b and 10e to form an outflow opening 12b and an inflow opening 11b, respectively. Furthermore, the hexagonal part 14 of connecting bodies 3a is provided at the bottom of hexagonal sides 10b and 10e respectively with recesses 18b, 18a, as a result of which the groove 16 is interrupted in these areas and to form inflow opening 11b and outflow opening 12b. Similarly, the hexagonal part 14 of connecting bodies 3b is provided at the bottom of hexagonal sides 10a and 10d with recesses 19a, 19b (not shown), as a result of which groove 16 is interrupted in these areas and to form inflow opening 11a and outflow opening 12a .

The circumferential shape and the cross-sections of the ribs 15 and the grooves 16 are matched to each other in such a way that they can engage with each other in a clamping, airtight or at least substantially airtight manner. The ribs 15 are provided with locating edges 17a, 17b to facilitate engagement during assembly. Alternatively or in combination, the ribs 15 and grooves 16 may also have a slightly tapered shape. As an alternative to the use of a press fit, it is also possible to shape the ribs 15 and the grooves 16 in such a way that they can click together to form a snap connection. To the extent that such a snap connection would be insufficiently airtight, it is further possible to use a soft seal between the ribs 15 and grooves 16 that could possibly be connected to the ribs 15 or the grooves 16. It would also be possible to make the connection airtight by welding adjacent connecting bodies 3, for example chemically or ultrasonically, or by gluing.

The aforementioned cover body 41 of heat exchanger 1 has a hexagonal plate-shaped part 43, the circumference of which is equal to that of hexagonal part 14. The plate-shaped part is provided on the underside with a circumferential (interrupted) groove similar to groove 16 for connection to the rib 15 of the upper layer 2. The aforementioned bottom body 42 of heat exchanger 1 has a hexagonal plate-shaped part 45, the circumference of which is also comparable with that of hexagonal part 14. At the top of the plate-shaped part 45, the bottom body 42 is provided with a circular (interrupted) rib 46 similar to rib 15 for connection to groove 16 of the bottom layer 2. Alternatively, the cover body and the bottom body could also have a differently shaped circumference, for example for the purpose of connections to air supply and air discharge provisions.

In applied form, two air supply channels (not shown in more detail) connect airtight to hexagonal sides 10a and 10e of heat exchanger 1 via which a two air flows are supplied to, on the one hand, the flow channels which connect to the inflow openings 11a and 11b. Furthermore, two air discharge channels (not shown) connect airtightly to the hexagonal sides 10b and 10d of the heat exchanger, so that the outflow openings 12b, 12a open out into such an air discharge channel and the air streams leave the heat exchanger 1 again after they have passed the flow channels. The various connections and connections between the connecting bodies 3 mutually and between the connecting bodies 3 on the one hand and the sheets 4 on the other hand is such that at least 97% of the air which flows into the heat exchanger 1 via inflow openings 11a, 11b the heat exchanger 1 and the heat exchanger 1 via outflow openings 12a , 12b. In operation, energy will be exchanged between, on the one hand, the air that flows through the flow channels that connect to inflow openings 11a and, on the other hand, the air that flows through the flow channels that connect to inflow openings 11b.

For the sake of completeness, it is noted that recuperators according to the invention may also have a shape other than a hexagonal shape, for example a rectangular such as a square shape. In the case of a hexagonal shape, the hexagonal sides may differ in their length. More specifically, for example, the hexagonal sides 10c and 10f can be longer than the remaining hexagonal sides 10a, 10b, 10d and 10e. The recuperators can not only be of the countercurrent type but also of the co-current type or the cross-current type. Although the inflow openings and outflow openings are now surrounded by two adjacent connecting bodies 3, it is also possible to provide the inflow openings and / or the outflow openings in a single connecting body. Each of the inflow openings and / or the outflow openings are then completely surrounded by material from an associated connecting body. Furthermore, it is possible that the connecting bodies are not completely circumferential or actually consist of two or even more parts, each of which is provided with only one part of the circumference of a sheet, whereby use may be made of separate seals to prevent leakage of air.

Figures 3a to 3d show successive steps during the production of a layer 2a with a profiled sheet 4a. The profiling of sheet 4a is such that the profiling does not extend to the outer circumference of sheet 4a. There, therefore, there is a flat area 21. The flat area 21 is clamped between two mold parts 22, 23. Mold parts 22, 23 define between a mold cavity 24, the shape of which corresponds to that of the connecting part 3a. The flat region 21 of sheet 4a extends into the mold cavity 24. Via injection-molding ducts 25 each of which open into the mold cavity 24 and a number of which are provided distributed over the circumference of the mold cavity 24, liquid thermoplastic plastic, such as polystyrene or polyethylene, is supplied to the mold cavity 24 by means of injection molding (figures) 3c and 3d). The liquid plastic then solidifies during which solidification the plastic adheres to (the flat area 21 of) sheet 4a insofar as sheet 4a extends into the mold cavity 24. The choice of the material of the connecting parts 3 can be matched to that of sheet 4 to promote good adhesion. For an even stronger connection between a sheet 4 and the solidified plastic material, it is also conceivable to provide holes in sheet 4 so that the plastic material can extend through these holes and can also provide a mechanical anchoring. After solidification, the mold parts 22, 23 are opened by moving them apart. The product thus produced relates to a layer 2a (Figure 3e).

It will be clear to those skilled in the art that a layer 2b with a completely flat sheet 4b can also be produced in a comparable manner. The layers 2a and 2b can alternately be clamped onto each other (Figure 3f), the peaks 9 of the profiling of sheet 4a connecting to an adjacent flat sheet 4b, whereby flow channels are formed between adjacent sheets 4a and 4b. Layers 2a and 2b can be clamped together manually, but possibly also automated, for which a relatively simple assembly machine will suffice. This machine can be suitable for heat exchangers of different sizes where no or only limited changes are required

Figures 4a to 4c show successive steps of an alternative way of producing a layer 2, wherein after solidification of the plastic material as explained with reference to Figures 3a to 3e an additional mold cavity is provided on the underside of the connecting body 3 26 is formed by spraying down channel body 27, which extends the full length of groove 16, with respect to the lower mold body 23 '. Subsequently, liquid plastic material is supplied to the additional mold cavity 26 via the injection channel 28 in the injection channel body 27. The material of this plastic material differs from the plastic material in mold cavity 24 in that it behaves resiliently, like a rubber, in solidified form. After solidification of the plastic material in the additional mold cavity 26, it is adhered to the plastic material in mold cavity 24 and forms a seal 29. The product thus produced is referred to as layer 2a '. In a comparable manner, layer 2b can of course also be provided with a seal as seal 29. This layer is designated by reference numeral 2b '. The seal 29 serves to promote an airtight connection of adjacent layers 2a ", 2b" (Figure 4e).

Figures 5 to 7 relate to a heat exchanger 51 which can be considered as a variant of heat exchanger 1. The wall parts 61c and 61f on opposite hexagonal sides 60c and 60f of heat exchanger 51 are (seen in top view) on both ends are extended relative to the corresponding wall parts of heat exchanger 1. As a result, heat exchanger 51, at least the outside thereof, has the shape of a beam with a rectangular, more specifically square, top view. Like sheets 4 in heat exchanger 1, the sheets in the heat exchanger 51 are hexagonal in shape. The ends 64a, 64b of the parts of the connecting bodies 62a, 62b of layers 52a, 52b forming the wall parts 61c and 61f, which wall parts 64a, 64b in Figure 5 are located on the front side of heat exchanger 51, are in line with each other and with the truncated points 64c located between the parts of the connecting bodies 62a, 62b of layers 52a, 52b located on the hexagonal sides 60a and 60b. Thus, these ends 64a, 64b, points 64c together with cover body 71 and bottom body 72 form an abutment surface in the form of a horizontal block-shaped eight.

Figure 7 shows how funnel-shaped flow bodies 81, 82 are clamped against the two opposite contact surfaces of heat exchanger 51. Gaskets 83, 84 are provided between the flow bodies 81, 82 and the two associated contact surfaces. At the location of the two openings in the eight-shape of the abutment surfaces, both the gaskets 83, 84 and the flow bodies 81, 82 are also provided with uniform openings. For separating the air streams, the flow bodies 81, 82 comprise a partition 85 between the openings. The flow bodies 81, 82 clamp heat exchanger 51 between them with the aid of tension rods 86, which may, for example, be threaded and which extend through holes in the flow bodies 81, 82.

Claims (25)

CONCLUSIONS Recuperator comprising a number of neighboring sheets extending parallel to each other, which sheets are connected to each other at least a part of their circumference and wherein flow channels are formed between adjacent sheets, characterized in that each of the sheets has at least at its circumference is partially surrounded by and connected to an associated connecting body with adjacent connecting bodies being connected to each other at least at least a part of the circumference of the associated sheets and jointly forming the wall of a housing with flow openings provided in the wall being connected with the flow channels for admitting air to the flow channels via the flow openings. Recuperator according to claim 1, wherein the through-flow openings are formed between adjacent connecting bodies. Recuperator according to claim 1, wherein the flow openings are formed in connecting bodies. Recuperator according to claim 1, 2 or 3, wherein adjacent connecting bodies are provided on projecting sides with projecting parts and with recesses, the shapes of the projecting parts and of the recesses connecting to each other for mutually connecting the connecting bodies. Recuperator according to claim 4, wherein the projecting parts and / or the recesses have a tapered shape or at least partly a tapered shape. Recuperator according to one of the preceding claims, wherein adjacent connecting bodies are clampingly connected to each other. Recuperator according to one of the preceding claims, wherein adjacent connecting bodies are connected to each other by means of a press fit. Recuperator as claimed in any of the foregoing claims, wherein neighboring connecting bodies are connected to each other by means of a snap connection. 9. Recuperator according to one of the preceding claims, wherein the recuperator is provided with a sealing body between adjacent connecting bodies at the location of the mutual connection. The collector of claim 9, wherein the sealing body is connected to one of the two adjacent connecting bodies. A recycler according to any one of the preceding claims, wherein at least a portion of the sheets are permeable to moisture. Recuperator according to one of the preceding claims, wherein all sheets are provided with a profile. Recuperator according to any of claims 1 to 11, wherein the neighboring sheets are flat and alternately provided with a profile. Recuperator according to one of the preceding claims, wherein the sheets, preferably alternately, are made of different materials. The recycler of claim 14, wherein a portion of the plurality of sheets is made of a moisture-permeable material and the other portion of the plurality of sheets is made of a material that does not allow moisture to pass through. Recuperator according to claim 15, wherein the connecting bodies, preferably alternately, are made of different materials. A recycler according to any one of the preceding claims, wherein the sheets have a hexagonal shape and the circumference of the housing is beam-shaped. Recuperator according to one of the preceding claims, wherein each of the sheets is at least largely surrounded by an associated connecting body. The recycler of claim 18, wherein each of the sheets is completely surrounded by an associated connecting body. 20. Recuperator according to one of the preceding claims, wherein the connecting bodies are injection molded. A recycler according to claim 20, wherein the sheets along the first part of the periphery of the connecting bodies are injection-molded by the material of the connecting bodies during the injection molding of the connecting bodies on the periphery of the sheets. A method of producing a connecting body for use in a recuperator according to any of the preceding claims comprising the steps of closing a mold creating a closed mold cavity a sheet on at least a portion of the circumference of the sheet in the mold cavity is positioned, the injection molding of the connecting body into the mold, wherein the sheet in the mold cavity at the area of at least a part of the peripheral edge of the sheet is sprayed on by the material of the connecting body. The method of claim 22 further comprising the steps of injection molding a sealing body against the connecting body. A method for producing a recuperator according to any of claims 1 to 21, comprising the steps of providing circumferential connecting bodies each with a sheet connected to the associated connecting body and extending on the inside of the circumferential connecting body connecting adjacent connecting bodies to each other such that flow channels arise between adjacent sheets associated with adjacent connecting bodies. A method according to claim 24, wherein adjacent connecting bodies are connected to each other by clamping adjacent connecting bodies to each other, preferably by means of a press fit.