Gasket unit inserts for heat exchangers

Abstract

The present invention relates to a gasket unit which is suitable for being sandwiched between the peripheral areas of two adjacent heat transfer plates of a plate heat exchanger, wherein the gasket unit is formed by a base having a gasket on the surface.

Description

Background Art

[0001] The conventional structure of a plate heat exchanger includes a plurality of heat transfer plates stacked on top of each other. The heat transfer plates are formed with a pattern so that a flow path is formed between each set of adjacent heat transfer plates. The inlet and outlet of the flow path for the fluid may be formed as openings in the heat transfer plates. Some heat exchangers braze the plates together, while in other heat exchangers, gaskets are positioned between the heat transfer plates and in gasket grooves formed in the heat transfer plates. The gaskets are then arranged at the edge portions of the heat transfer plates to seal the flow path, and at the areas around the openings to seal the paired openings, so that only two of the openings have a flow passage to the flow path formed on one side of the heat transfer plate, while the other two openings are sealed relative to the flow path.

[0002] The frame plates may be connected and fastened to the stack of heat exchanger plates, for example at the top and bottom, and have a significant thickness compared to the heat transfer plates in order to withstand the larger loads.

[0003] A known problem with gasketed heat exchangers is that the gaskets tend to deform and / or be squeezed slightly out of place. Another problem is that heat transfer plates are traditionally patterned at the periphery and in the opening areas in addition to the pattern in the heat transfer section. This generally makes the manufacture of the plates very complicated and increases the likelihood of misalignment when the plates are assembled in the heat exchanger. It also increases the likelihood of introducing weak points or areas in the plates. The present invention is intended to overcome these problems. Summary of the invention

[0004] In order to solve these problems, the present invention introduces a gasket unit adapted to be sandwiched between the peripheral areas of two adjacent heat transfer plates of a plate heat exchanger, wherein the gasket unit is formed by a base having a gasket on the surface.

[0005] The base may be substantially more rigid and less compressible than the material of the liner.

[0006] The base may be incompressible to the forces present in the assembled heat exchanger so as to prevent significant deformation when assembled into the heat exchanger, while the gasket is made of a sufficiently soft material so that it is compressed and deformed when it is sandwiched between the two heat exchanger plates to ensure full contact.

[0007] Portions of a gasket may be formed on two surfaces of the base adapted to face the respective two heat exchanger plates so as to seal against both the upper and lower heat transfer plates.

[0008] The gasket may surround an inner hollow portion of the base, wherein the inner hollow portion may be adapted to bring the two heat transfer plates into contact in a heat transfer area defined by the two heat transfer plates when connected in a heat exchanger.

[0009] The base may be formed with a sealing oblique support portion having an oblique gasket section, the sealing oblique support portion being adapted to separate a spacer opening for the first flow path opening or the second flow path opening from the inner hollow portion, and the sealing oblique support portion being adapted to be positioned in the oblique region of the heat transfer plate and to seal the fluid communication between the corresponding first flow path or the second flow path and the heat transfer region of the heat transfer plate.

[0010] In one embodiment, a second gasket separate from the gasket surrounds the first flow path opening or the second flow path opening.

[0011] The cushion may be incorporated as part of the base unit.

[0012] The gasket may be moulded to the spacer, for example by injection moulding.

[0013] The base may comprise an outer non-gasketed section and an inner gasketed section with the gasket, wherein both sections are adapted to contact the two heat transfer plates, wherein only the gasket is adapted to be compressed between the two heat transfer plates.

[0014] The invention further introduces a heat exchanger formed by a stack of structured heat transfer plates, each structured heat transfer plate being provided with two pairs of openings, each pair of openings providing an inlet and an outlet to a first flow path on one side of the heat transfer plate and a second flow path on a second side of the heat transfer plate, respectively, and wherein a gasket unit according to any of the preceding claims is positioned between at least two adjoining adjacent heat transfer plates in the plate peripheral zone.

[0015] The gasket unit in the heat exchanger may be positioned between any two adjacent heat transfer plates.

[0016] The stack of heat transfer plates may be positioned between two frame plates and wherein a gasket unit is positioned between a frame plate and the adjoining adjacent heat transfer plates. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A plate heat exchanger and a heat transfer plate of the gasket type according to the prior art.

[0018] Figure 2 is a diagrammatic representation of an element with a gasketed spacer and a heat transfer plate.

[0019] Figure 3 is an illustration of a spacer with an integrated liner.

[0020] Figure 4A and Figure 4B are illustrations of top and bottom views of a portion of a spacer with an integrated liner in an oblique region.

[0021] Figure 5 Heat transfer plates suitable for spacers and gaskets.

[0022] Fig. 6A and Figure 6B is an illustration of a gasket attached to one side of a spacer. DETAILED DESCRIPTION

[0023] Figure 1 An example of a plate heat exchanger 10 formed by a collection or stack of structured heat transfer plates 11 is shown. Each of the heat transfer plates 11 is provided with two pairs of openings, wherein a first pair of openings 14 provides an inlet and an outlet for a first flow path formed on one side of the heat transfer plate 11, and a second pair of openings 15 provides an inlet and an outlet for a second flow path formed on a second side of the heat transfer plate 11, the second side being opposite to the first side. The openings 14, 15 of the stacked heat transfer plates 11 form a passage through the plate stack. In the illustrated example, the heat transfer plates 11 are adapted to receive gaskets 12 at the peripheral portions to seal the flow path formed between each two adjacent plates 11 with respect to the outside, respectively, and to seal a pair of openings 14, 15, wherein on the opposite side of the heat transfer plate 11, the corresponding other pair of openings 15, 14 is sealed. Furthermore, the plate stack is arranged between two frame plates 50, held together by rods 52, which hold the heat transfer plates 11 tightly together under compression. At least one of the frame plates 50 comprises an opening 51 which is aligned with the openings 14, 15 of the heat transfer plates and is connected to an external fluid pipe.

[0024] The heat transfer plate 11 in direct contact with the fluid may be substantially thin to enable rapid heat exchange between the corresponding hot fluid and cold fluid, and is made of a medium-resistant material.

[0025] The frame plate 50 is relatively thick compared to the heat transfer plates 11 in order to withstand both the internal forces from the stack of heat transfer plates 11 being compressed and certain external impacts that the frame plate 50 may encounter.

[0026] The peripheral portions of the heat transfer plates 11 are conventionally patterned, for example by corrugation, so as to contact the pattern of an adjoining adjacent heat transfer plate 11 and form a barrier to the gasket 12. The patterns may be connected by forming sections of a wall against which the gasket 12 rests.

[0027] The gasket 12 is positioned at the periphery of the first and second flow paths including the heat transfer area 13 formed between the connected heat transfer plates 11 , thereby sealing the flow paths and the heat transfer area 13 from the outside of the heat exchanger 10 .

[0028] The gasket 12 is also formed with a gasket diagonal section 12A, which is positioned at the diagonal area of ​​the heat transfer plate 11. The diagonal area is the intersection between the openings 14, 15 and the heat transfer area 13. The gasket 12 on one side provides the gasket diagonal section 12A for the second pair of openings 15, 14, thereby sealing the second pair of openings 15, 14 relative to the first flow path, and the gasket 12 on the second side provides the second gasket diagonal section 12A for the first pair of openings 14, 15, thereby sealing the first pair of openings 14, 15 relative to the second flow path.

[0029] Figure 2 An alternative gasket type heat exchanger 10 is shown, wherein spacers 100 or gasket units 100 are positioned between heat transfer plates 11 in the plate perimeter region 16. The figure shows the components in a heat exchanger 10, but not when fully assembled into the heat exchanger 10.

[0030] Hereinafter, when the spacer 100 is mentioned, the pad unit 100 will also be referred to, and vice versa.

[0031] The spacer 100 may be formed with a base 101 including an outer gasket-free section 101A and an inner gasket section 101B with a gasket 102. The outer gasket-free section 101A may be formed with auxiliary means 19, 119, 120, 118, such as alignment / guiding means 19, 119, 120 for guiding the spacer 100 to a correct orientation and position, and / or connecting or locking means 118 for connecting or locking the spacer 100 to a proper position. When two heat transfer plates 11 are stacked in the heat exchanger 11, both sections 101A, 101B are adapted to contact the two heat transfer plates 11, but only the gasket is adapted to be compressed between the two heat transfer plates 11. This enables the base 101 including the outer unlined section 101A to form a support for the plate perimeter region 16 and enables the gasket 12 in the inner gasket section 101B to form a seal to the inner heat transfer area 13 towards the outer and outer unlined section 101A.

[0032] The outer unlined section 101A may constitute at least 2 / 3 of the width, or even 3 / 4 of the width, or 4 / 5 of the width of the entire width of the spacer 100. Accordingly, the inner lined section 101B may constitute less than or equal to 1 / 3, 1 / 4, or 1 / 5 of the width of the entire width of the spacer 100.

[0033] The spacers 100 may be positioned between the frame plate 50 and the adjacent heat transfer plates 11, and between the individual heat transfer plates 11. The spacers 100 may be positioned between some or all of the heat transfer plates 11.

[0034] The spacer 100 replaces the contact pattern conventionally formed at the peripheral portion of the heat transfer plate 11 for contacting the pattern of the adjacent adjacent heat transfer plate 11. Therefore, the plate peripheral area 16 formed outside the heat transfer area 13 does not have to be patterned, but can be substantially flat or planar, or at least has no section or area in contact with the adjacent plate.

[0035] The auxiliary means of the spacer 100 may include spacer rod openings 118, for example formed in the outer unlined section 101A, which are adapted to align with the plate rod openings 18 formed in the plate peripheral area 16. These form means for connecting or locking the spacer 100 in place. The heat transfer plates 11 are stacked with the spacer 100 between them and the frame plates 50 at the top and bottom. The rods can then be introduced through the spacer rod openings 118, the plate rod openings 18 and the openings in the frame plates. The parts can then be kept tightly connected, for example by bolts located at the ends of the rods. This has the additional advantage of keeping the spacer 100 fixed in place.

[0036] In one embodiment, the attachment or locking means of the auxiliary device may be formed as an upwardly protruding feature of the outer non-liner section 101A adapted to fit into an opening or protrusion formed in the peripheral region 16 .

[0037] An inner hollow portion 103 is formed in the spacer 100 and is surrounded by the base 101 and the gasket 102. In the case where the base 101 is adapted to be sandwiched between the peripheral regions 16 of two adjacent heat transfer plates 11 of the plate heat exchanger 10, the inner hollow portion 103 is adapted for the two heat transfer plates 11 to contact in the heat transfer area 36 defined by the two heat transfer plates 11 connected.

[0038] Figure 3 A spacer 100 is shown comprising two pairs of spacer openings 114 , 115 adapted to align with the plate openings 14 , 15 .

[0039] The pads 102, 102A, 102B are incorporated as part of the spacer 100 so that the spacer 100 becomes a pad unit 100, or the pads are fixed to the spacer 100, or the pads may be inserted into recesses or grooves formed in the surface of the spacer 100. The pads 102, 102A, 102B may, for example, be molded to the spacer 100, for example by injection molding.

[0040] To assist in assembly and ensure the correct orientation of the spacer 100, the assisting means may include a poka-yoke protruding feature 120 adapted to cooperate with a poka-yoke receiving feature 19 formed in the heat transfer plate 11, for example in the plate peripheral region 16. The shape of the poka-yoke protruding feature 120 and the associated poka-yoke receiving feature 19 of the plate is such that only the correct orientation and positioning of the spacer 100 relative to the heat transfer plate 11 is possible. In an alternative embodiment, the heat transfer plate 11 is formed with a poka-yoke protruding feature 120 and the spacer 100 is formed with a poka-yoke receiving feature 19. In either embodiment, the spacer 100 may be provided with a poka-yoke receiving feature 119 adapted to align with the poka-yoke receiving feature 19 of the plate.

[0041] Not all surfaces of the spacer 100 need to be in contact with the heat transfer plate 11, and the spacer 100 may, for example, include a contact section 130 along the edge of the spacer 100, around the periphery of the spacer rod opening 118, by a protrusion, or simply as a protrusion such as a raised edge. In the same way, such a spacer may be a lattice structure or formed with a lattice structure, or generally be hollow only at a portion relative to the outside of the gasket 102, 102A, 102B. This reduces the amount of material used for the spacer 100 and reduces the weight.

[0042] Figure 4A A section of the spacer 100 is shown in the region of two spacer openings 114 , 115 , a first spacer opening 114 for a first flow path and a second spacer opening 115 for a second flow path.

[0043] The spacer 100 may include a sealing diagonal support portion (section) 104 that connects the main part of the spacer 100 at two locations on opposite sides of the spacer openings 114, 115. The sealing diagonal support portion 104 is provided with a diagonal section 102A of the gasket that is connected to the main gasket 102 in the same manner at two locations on opposite sides of the spacer openings 114, 115. The sealing diagonal support portion 104 is adapted to be positioned in the diagonal section of the heat transfer plate 11 and thereby form a partition wall between the spacer openings 114, 115 and the inner hollow portion 103 and thereby form a seal between the plate openings 14, 15 and the heat transfer area 13 when the sealing diagonal support portion 104 is sandwiched between two heat transfer plates 11 in an assembled heat exchanger.

[0044] In a conventional heat exchanger, the heat transfer plates 11 may be formed with a pattern that contacts adjacent heat transfer plates 11 for support, leaving channels or openings for fluid to pass through.

[0045] In this embodiment, the oblique areas of the heat transfer plates 11 do not need to be formed with any support structure or pattern, but may be substantially flat or planar, or at least not in direct contact with adjacent heat transfer plates 11 .

[0046] The second pad 102B connected to the support member 100 can be formed around the spacer openings 114, 115, and can be separate from the pad 112 and the diagonal pad section 112A, or connected to any one of the pad 112 and the diagonal pad section 112A. As shown, the main portion of the pad 112 and the diagonal pad section 112A can extend as a continuous portion, and there is no portion located outside the spacer openings 114, 114. In an alternative embodiment, the main pad portion 112 surrounds the spacer 100, and all of the spacer openings 114, 115 and the diagonal pad section 112A extend inside the openings 114, 115 so as to be sealed relative to the inner hollow portion 105, connecting the main pad portion 112 on both sides of the corresponding openings 114, 115 like branches.

[0047] The spacer 100 may comprise support means 103 for the diagonal areas, adapted to support the diagonal areas of the heat transfer plates 11 with the openings 14, 15 of the heat transfer plates 11 not supported by the gasket to allow flow to pass through the heat transfer area 13. This may be formed as a (one or more) porous diagonal support portion (section) 103. This portion is adapted to support the heat transfer plates 11 in the otherwise unsupported sections, such as the diagonal areas associated with the plate openings 14, 15, where flow will enter and exit through the heat transfer area 13. In a conventional heat exchanger, the heat transfer plates 11 in this area may be formed with a pattern of contacting adjacent heat transfer plates 11 for support, leaving channels or openings for the fluid to pass through.

[0048] In this embodiment, the oblique areas of the heat transfer plates 11 do not need to be formed with any support structure or pattern, but may be substantially flat or planar, or at least not in direct contact with adjacent heat transfer plates 11 .

[0049] In the illustrated embodiment, the porosity of the porous diagonal support portion 103 is ensured by forming an oblique spacer flow path 103A between the oblique spacer support portions 103B, which are adapted to contact two adjacent heat transfer plates 11. The oblique spacer flow path 103A may be formed in any manner, such as holes or holes in the porous diagonal support portion 103 of an other entity, as a free section between the oblique spacer support portions 103B, or in any other form.

[0050] Figure 4B The support member 100 is shown relative to Figure 4A , where it can be seen that one side of the porous oblique supporting portion 103 has a flat surface, which forms a common oblique supporting portion 103B, which contacts the surface of one of the heat transfer plates 11, while the porous oblique supporting portion 103 is formed with a columnar oblique supporting portion 103B on the other side for contacting the adjacent adjacent heat transfer plate 11.

[0051] In the illustrated embodiment, the porous diagonal support portion 103 is formed by two connected concentric semicircular portions located in the diagonal region and contacts the main portion of the spacer 100 on opposite sides of the spacer openings 114 , 115 .

[0052] The spacer 100 may be formed with gaskets 102, 102A, 102B on both surfaces, thereby having portions or gasket surfaces of the gaskets 102, 102A, 102B contacting both upper and lower portions of two adjoining adjacent heat transfer plates 11. In one embodiment, the gaskets 102, 102A, 102B are positioned or formed on both surfaces.

[0053] As previously described, the gasket 102 may be positioned at the inner peripheral portion of the spacer 100, such as at the inner gasket section 101B of the base, so that the portion outside the heat transfer area 13 (e.g., the outer non-gasketed section 101A of the base) may be formed with openings, such as the spacer rod openings 118. This ensures that these openings are sealed relative to the flow path within the heat exchanger 10.

[0054] In one embodiment, the base 101 is formed of two separate parts, wherein the outer non-padded section 101A of the base is positioned outside the inner padded section 101B of the base. Thus, the outer non-padded section 101A of the base, which is located outside, forms an outer support for the inner padded section 101B of the base, which is used to hold the inner padded section 101B of the base in place, wherein the outer non-padded section 101A of the base can be fixed, for example, by the rod 52.

[0055] In another embodiment, the pads 12, 112 are positioned against the inner edge surface of the outer unpadded section 101A of the base, which thereby forms an outer support portion for the spacer 100 and pads 12, 112. In this embodiment, the inner edge surface can be shaped to match the shape of the pads 12, 112.

[0056] In one embodiment, a gasket unit 100 is introduced with a base 101 comprising an inner gasket section 101B of the base having gaskets 102, 102A, 102B. Thus, the rigidity of the base 101 will help to keep the gaskets 102, 102A, 102B in place, and this concept can be combined with the traditional corrugations in the plate peripheral area 16 outside the gasket unit 100, which will prevent the gaskets 102, 102A, 102B from being squeezed out of place under the pressure in the heat exchanger 10.

[0057] Figure 5 An embodiment heat transfer plate 11 suitable for being assembled into a heat exchanger 10 is shown with spacers 100 between the heat transfer plates 11, wherein the outer peripheral edge portion 17 is curved in addition to the protrusions or corrugations defining the flow path in the heat transfer area 13. The curved outer peripheral edge 17 can contact the outer surface of the spacer 100 when stacked and thereby help to hold the spacer 100 in place. Another advantage is that when assembling the heat exchanger 10, the curved outer peripheral edge 17 helps to guide the heat transfer plates 11 into place.

[0058] The curved section 17 may be smooth as shown, or may be formed as such, for example with waves or corrugations for added strength.

[0059] Fig. 6A and Figure 6B An embodiment is shown in which the free liner 102 is adapted to be connected to the spacer 100, for example, the free liner 102 is adapted to be connected to the inner side of the spacer 100 facing the inner hollow portion 105. In the illustrated embodiment, the spacer 100 is formed with a connection section 100A adapted to cooperate with the liner connection section 102C. Either the spacer connection section 100A or the liner connection section 102C may be formed as an extension 100A adapted to be fitted into the recess 102C of the other. In the illustration, the spacer 100 is provided with an extension, and the liner 102 is provided with a recess, but the reverse is also possible.

[0060] In one embodiment, parts such as the porous oblique support portion 103 including the oblique spacer support portion 103B and / or the sealing oblique support portion 104 are made of the same material as the gasket. In an embodiment where the gasket 102 is positioned at the inner surface facing the inner hollow portion 105, the porous oblique support portion 103 including the oblique spacer support portion 103B and / or the sealing oblique support 104 can be formed as a part of the gasket 102 instead of a part of the spacer 100.

[0061] List of reference numerals:

[0062] 10-Plate heat exchanger

[0063] 11-Heat transfer plate

[0064] 12-Padding

[0065] 12A-Pad oblique section

[0066] 13-Heat transfer area

[0067] 14 - Opening for the first flow path

[0068] 15 - Opening for the second flow path

[0069] 16-Plate peripheral area

[0070] 17- Curved peripheral edge section of the plate

[0071] 18- Plate rod opening

[0072] 19- Board error-proofing feature

[0073] 50-Frame Plate

[0074] 51-Frame plate opening

[0075] 52-Rod and Bolt

[0076] 100-Spacer Insert / Gasket Unit

[0077] 100A-Spacer connection section

[0078] 101-base

[0079] 101A - External unpadded section of base

[0080] 101B - Inner pad section of base

[0081] 102-Padding

[0082] 102A-Pad oblique section

[0083] 102B-Second liner

[0084] 102C-Gasket connection section

[0085] 103-Porous oblique support section (section)

[0086] 103A - Oblique spacer flow path

[0087] 103B- oblique spacer support

[0088] 104- Sealing oblique support portion (section)

[0089] 105-Inner hollow part

[0090] 114 - Spacer opening for first flow path

[0091] 115 - Spacer opening for second flow path

[0092] 118-Spacer Rod Opening

[0093] 119-Insert Mistake-Proofing Receiving Feature

[0094] 120- Error-proofing feature

[0095] 130-Contact section.

Claims

1. A gasket unit (100), the gasket unit being adapted to be sandwiched between the peripheral regions (16) of two adjacent heat transfer plates (11) of a plate heat exchanger (10), wherein: The gasket unit (100) is formed by a base (101) having gaskets (102, 102A, 102B) on the surface, wherein the heat transfer plate (11) is provided with openings (14, 15) providing inlets and outlets to corresponding flow paths of the heat transfer plate (11), wherein the base (101) comprises support means (103) for an oblique area of ​​the heat transfer plate (11) so that the oblique area of ​​the heat transfer plate is not supported by the gasket, thereby allowing flow to pass through the heat transfer area (13) of the heat transfer plate (11), the oblique area being the intersection of the openings (14, 15) and the heat transfer area (13) of the heat transfer plate (11).

2. The pad unit (100) according to claim 1, wherein: The base (101) is more rigid and less compressible than the material of the pad (102, 102A, 102B).

3. The pad unit (100) according to claim 2, wherein: The base (101) is incompressible to the forces present in the assembled heat exchanger (10), while the gaskets (102, 102A, 102B) are made of a soft material so that when the gaskets are sandwiched between the two heat transfer plates (11) they are compressed and deformed to ensure full contact.

4. The pad unit (100) according to claim 1, 2 or 3, wherein: Portions of gaskets (102, 102A, 102B) are formed on two surfaces of the base (101) adapted to face the corresponding two heat transfer plates (11).

5. The pad unit (100) according to any one of claims 1 to 3, wherein: The liner (102) surrounds the inner hollow portion (105) of the base (101).

6. The pad unit (100) according to claim 5, wherein: The inner hollow portion (105) is suitable for bringing the two heat transfer plates (11) into contact in a heat transfer area (36) defined by the two heat transfer plates (11) when connected in a heat exchanger (10).

7. The pad unit (100) according to claim 5, wherein: The base (101) is formed with a sealing oblique support portion (104) having an oblique gasket section (102A), the sealing oblique support portion being suitable for separating a gasket unit opening (114, 115) for a first flow path opening or a second flow path opening from the inner hollow portion (105), and the sealing oblique support portion being suitable for being positioned in the oblique region of the heat transfer plate (11) and being suitable for sealing the fluid communication between the corresponding first flow path or the second flow path and the heat transfer region (13) of the heat transfer plate (11).

8. The pad unit (100) according to any one of claims 1 to 3, wherein: A second gasket (102B) separated from the gasket (102) surrounds the first flow path opening or the second flow path opening.

9. The pad unit (100) according to any one of claims 1 to 3, wherein: The pads (102, 102A, 102B) are incorporated as part of the base (101).

10. The pad unit (100) according to any one of claims 1 to 3, wherein: The pad (102, 102A, 102B) is molded to the pad unit (100).

11. The pad unit (100) according to claim 10, wherein: The pad (102, 102A, 102B) is molded to the pad unit (100) by injection molding.

12. The pad unit (100) according to any one of claims 1 to 3, wherein: The base (101) comprises an outer non-gasketed section (101A) and an inner gasketed section (101B) with the gasket (102, 102A, 102B), wherein both sections (101A, 101B) are adapted to contact the two heat transfer plates (11), wherein only the gasket is adapted to be compressed between the two heat transfer plates (11).

13. The pad unit (100) according to claim 12, wherein: The outer unlined section (101A) is formed with auxiliary means (19, 119, 120, 118).

14. The pad unit (100) according to claim 13, wherein: The auxiliary device is an alignment / guiding device (19, 119, 120) for guiding the cushion unit (100) to a correct orientation and position, and / or a connecting or locking device (118) for connecting or locking the cushion unit (100) in a proper position.

15. A heat exchanger (10) formed by a stack of structured heat transfer plates (11), each structured heat transfer plate being provided with two pairs of openings (14, 15), each pair of openings providing an inlet and an outlet to a first flow path on one side of the heat transfer plate (11) and a second flow path on a second side of the heat transfer plate (11), respectively, and wherein a gasket unit (100) according to any of the preceding claims is positioned between at least two adjacent adjacent heat transfer plates (11) in a plate peripheral region (16).

16. The heat exchanger (10) according to claim 15, wherein: The gasket unit (100) is positioned between any two adjacent heat transfer plates (11).

17. The heat exchanger (10) according to claim 15 or 16, wherein: The stack of heat transfer plates (11) is positioned between two frame plates (50), and a gasket unit (100) is positioned between a frame plate (50) and the adjoining adjacent heat transfer plate (11).

Images