Mounting means and heat transfer plate

Abstract

A mounting means (58) for securing the gasket (48) to the heat transfer plate (4) and the heat transfer plate (4) are provided. The mounting means (58) includes a connecting member (62), a first finger (64), a second finger (66), and a bridge (60). A first connecting portion (68) of the connecting member (62) is positioned to engage the gasket (48), and a second connecting portion (70) of the connecting member (62) engages the bridge (60). A connecting portion (72) of the first finger (64) engages the bridge (60), and a connecting portion (74) of the second finger (66) engages the bridge (60). The first finger (64) and the second finger (66) are configured to extend from the bridge (60) toward the gasket (48). The connecting member (62) extends between the first finger (64) and the second finger (66). The attachment means is characterized in that the connecting member (62) comprises a first portion (621) having a first width (wc1) and a second portion (622) having a second width (wc2). The second portion (622) is disposed closer to the bridge (60) than the first portion (621), and the second width (wc2) is smaller than the first width (wc1).

Description

[Technical Field]

[0001] The present invention relates to attachment means for securing a gasket to a heat transfer plate, as well as to a heat transfer plate configured to cooperate with such attachment means. [Background technology]

[0002] Plate heat exchangers (PHEs) typically include two end plates between which a number of heat transfer plates are aligned, i.e., stacked or packed. The heat transfer plates in a PHE can be of the same or different types and can be stacked in different ways. In some PHEs, the heat transfer plates are stacked so that the top and bottom sides of one heat transfer plate face the top and bottom sides, respectively, of the other heat transfer plate, and every other heat transfer plate can be positioned upside down relative to the remaining heat transfer plates. This is commonly referred to as the heat transfer plates being "rotated" relative to each other. In other PHEs, the heat transfer plates are stacked so that the top and bottom sides of one heat transfer plate face the top and bottom sides, respectively, of the other heat transfer plate, and every other heat transfer plate can be upside down relative to the remaining heat transfer plates. This is commonly referred to as the heat transfer plates being "inverted" relative to each other.

[0003] In one known type of PHE, the so-called gasketed PHE, gaskets are positioned between the heat transfer plates in gasket grooves pressed into the plates. Typically, the gasket grooves extend adjacently and partially along the edges of the heat transfer plates. The end plates, and therefore the heat transfer plates, are pressed together by some type of fastening means, thereby forming a gasket seal between the heat transfer plates. Parallel flow paths defined by the gaskets are formed between the heat transfer plates, with one channel between each pair of adjacent heat transfer plates. Two fluids, initially at different temperatures, are supplied to the PHE through inlets and exit the PHE through outlets. They alternate through alternate channels to transfer heat from one fluid to the other. In the electric heating plates, which are connected to the PHE inlets and outlets, the fluids enter and exit the channels through inlet and outlet portholes. Proper gasket placement between the plates is essential to ensure leak-proof channels.

[0004] When a plate heat exchanger is closed, the gasket is pressed between the plates and held firmly in place. However, when the gasket is not sandwiched between the plates, such as when the plate heat exchanger is assembled or opened for maintenance, some means for properly securing the gasket to the plates is desirable. It is known to use adhesive means, such as glue or tape, to secure the gasket to the plates. However, installing or replacing an adhesively secured gasket can be relatively time-consuming and therefore expensive. Furthermore, the adhesive can adversely affect the gasket and its sealing ability. Mechanical gasket securing solutions have also been known for some time, for example, in the applicant's own U.S. Pat. No. 4,635,715 (Patent Document 1). This document discloses different embodiments of gaskets with protrusions for securing the gasket to the heat transfer plate. The gaskets described therein can be relatively unstable in their securing to the heat transfer plate due to a relatively weak engagement between the protrusions and the heat transfer plate, which poses a risk of the protrusions "sliding off" the heat transfer plate. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 4,635,715 Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide a mounting means for securing a gasket to a heat transfer plate, and a heat transfer plate configured to engage with such mounting means, which provides a more secure gasket fixation than the prior art. The basic concept of the present invention is to construct the mounting means and the heat transfer plate so that they "interlock" when properly engaged with each other.

[0007] The mounting means and the electric heating plate are defined in the appended claims and described below. [Means for solving the problem]

[0008] The mounting means according to the present invention is configured to engage with an edge of a heat transfer plate to secure a gasket to a first surface of the heat transfer plate. It comprises a connecting member, a first finger, a second finger, and a bridge. The first connecting portion of the connecting member is configured to engage with the gasket, and the second connecting portion of the connecting member engages with the bridge. The connecting portion of the first finger and the connecting portion of the second finger engage with the bridge. The first and second fingers are configured to extend from the bridge toward the gasket, and the connecting member extends between the first and second fingers. The mounting means is characterized in that the connecting member comprises a first portion having a first width and a second portion having a second width. The second portion is positioned closer to the bridge than the first portion, and the second width is smaller than the first width. The width of the connecting member can be measured parallel to the extension length of the bridge.

[0009] The first and second widths of the connecting member described above may vary or may be constant.

[0010] The connecting member may have a longitudinal axis of symmetry that extends perpendicular to and through the center of the bridge.

[0011] The first finger may not have a longitudinal axis of symmetry.

[0012] The attachment means according to the invention therefore has a connecting member whose width varies along at least part of its length, and which, in a heat transfer plate with a suitable design, is configured to be mechanically "self-locking" in at least one direction, which "self-locks" the attachment means firmly to the heat transfer plate and can prevent displacement of the attachment means relative to the heat transfer plate, in particular in a direction perpendicular to the width extension of the connecting member and parallel to the extension plane of the heat transfer plate.

[0013] The attachment means may be designed so that the second portion of the connecting member constitutes a second connection of the connecting member, which then abuts the bridge.

[0014] The second portion of the connecting member can have many different shapes. According to one embodiment of the present invention, it is tapered along at least a portion of its length in the direction toward the bridge. Such a design allows for a smooth transition between the first and second portions of the connecting member, thereby allowing for a convenient and durable attachment means.

[0015] The attachment means may further comprise a third portion of the connecting member having a third width, the first portion of the connecting member being disposed between the second and third portions of the connecting member, the third width being less than the first width. This configuration may allow the attachment means to include connecting members configured to mechanically "self-lock" in at least two opposite directions within the heat transfer plate with appropriate design, as well as more secure fixation of the attachment means to the heat transfer plate.

[0016] The attachment means may be designed so that the third portion of the connecting member constitutes the first connecting portion of the connecting member, and the third portion of the connecting member is arranged to abut the gasket.

[0017] The third portion of the connecting member can have many different shapes. According to one embodiment of the present invention, the bridge is tapered away from the bridge along at least a portion of its length. Such a design can allow for a smooth transition between the first and third portions of the connecting member, thereby allowing for a convenient and durable attachment means.

[0018] The attachment means may be configured such that the first finger includes a first portion having a first width and a second portion having a second width. The second portion may be positioned closer to the bridge than the first portion, and the first width may be smaller than the second width. The width of the first finger may be measured parallel to the extension length of the bridge. This design may make it easier to properly engage the attachment means with the electric heating plate. Furthermore, this design may make the first finger more flexible, resulting in a stronger engagement between the attachment means and the electric heating plate. This design may also allow the shape of the first finger to match the shape of the connecting member, thereby enabling a compact attachment means.

[0019] The first width and second width of the first finger described above may vary or may be constant.

[0020] The attachment means may be designed such that the second portion of the first finger constitutes the connecting portion of the first finger, and the second portion of the first finger abuts the bridge.

[0021] The second portion of the first finger can have many different shapes. According to one embodiment of the present invention, the bridge tapers away from the bridge along at least a portion of its length. Such a design can allow for a smooth transition between the first and second portions of the first finger, thereby enabling a convenient and durable attachment means.

[0022] The attachment means may be designed such that the outer longitudinal face of the first finger, i.e. the face opposite the connecting member, is essentially straight and extends essentially perpendicular to the extension length of the bridge. Such a design allows the shape of the first finger to match the shape of the connecting member, which may thus allow for a compact attachment means.

[0023] The attachment means may be configured such that the bridge thickness is greater than the first finger thickness. This design allows the first finger to be more flexible than the bridge. This in turn makes it easier for the attachment means to properly engage with the heating plate, resulting in a stronger engagement between the attachment means and the heating plate.

[0024] Naturally, the second finger of the attachment means may be designed similarly to the first finger of the attachment means.

[0025] A heat transfer plate according to the present invention has a gasket groove on its first side extending along the edge of the heat transfer plate. The edge of the heat transfer plate extends between the edge and the gasket groove and is corrugated with alternating ridges and valleys when viewed from the first side of the heat transfer plate. The edge has a gasket fastening area configured to engage with a mounting means as defined above to secure the gasket in the gasket groove. The gasket fastening area includes a first valley and first and second ridges, the first and second ridges being located on either side of the first valley. The heat transfer plate is characterized in that the first valley has a first portion having a first width and a second portion having a second width. The second portion is located closer to the edge than the first portion, and the second width is smaller than the first width. The widths of the ridges and valleys can be measured parallel to the extension length of the gasket groove.

[0026] The first valley may have a longitudinal axis of symmetry that extends perpendicular to the edge.

[0027] The first ridge may not have a longitudinal axis of symmetry.

[0028] The heat transfer plate may be designed such that the second portion of the first valley tapers along at least a portion of its length in a direction toward the edge.

[0029] The first valley may further comprise a third portion having a third width, the first portion of the first valley being disposed between the second portion and the third portion of the first valley, and the third width being less than the first width.

[0030] The third portion of the first valley may be tapered away from the edge along at least a portion of its length.

[0031] The first ridge may comprise a first portion having a first width and a second portion having a second width, the second portion being positioned closer to the edge than the first portion, and the first width being smaller than the second width.

[0032] The second portion of the first ridge may be tapered away from the edge along at least a portion of its length.

[0033] An outer longitudinal side of the first ridge may be essentially straight and extend essentially perpendicular to the edge of the heat transfer plate.

[0034] The first valley may be at least partially open toward the gasket groove. This means that the first valley, more specifically, the space defined by the first valley, is in communication with the gasket groove, more specifically, the space defined by the gasket groove. This design allows the connecting member of the mounting means to extend within a plane defining the extension of the heat transfer plate and not affect the seal between the overlying heat transfer plate and the gasket. The first and second ridges may be closed toward the gasket groove or may be spaced away from the gasket groove. This means that the first and second ridges, more specifically, the space defined by the first and second ridges, are not in communication with the gasket groove, more specifically, the space defined by the gasket groove. This design allows the first and second ridges to fully support the gasket.

[0035] The heat transfer plate and the mounting means according to the present invention are adapted to be used together, and the design of the heat transfer plate is adapted to the design of the mounting means, and vice versa. Therefore, the above-mentioned different embodiments of the heat transfer plate according to the present invention correspond to the above-mentioned different embodiments of the mounting means according to the present invention. Therefore, the advantages of the above-mentioned different embodiments of the mounting means can be transferred to the above-mentioned different embodiments of the heat transfer plate. Naturally, these advantages only appear when the heat transfer plate and the mounting means cooperate with each other.

[0036] Further objects, features, aspects and advantages of the present invention will become apparent from the following detailed description and drawings. [Brief explanation of the drawings]

[0037] The invention will now be explained in more detail with reference to the accompanying schematic drawings.

[0038] [Figure 1] FIG. 1 is a plan view of an assembly including a heat transfer plate and gasket arrangement. [Figure 2] FIG. 2 is an enlarged partial view of the assembly of FIG. 1. [Figure 3] FIG. 2 is a further enlarged partial view of the assembly of FIG. 1. [Figure 4] 4 shows a schematic cross section along line AA in FIG. 3. [Figure 5] 4 shows a schematic cross section along line BB in FIG. 3. [Figure 6] This corresponds to FIG. 3, but shows only the heat transfer plate. [Figure 7] 2 shows a plan view of the attachment means of the gasket device of FIG. 1; [Figure 8] 8 shows a perspective view of the attachment means of FIG. 7. [Figure 9] 2 shows a plan view of an alternative attachment means for the gasket structure of FIG. 1; DETAILED DESCRIPTION OF THE INVENTION

[0039] 1-5, there is shown an assembly 2 including a heat transfer plate 4 and a gasket arrangement 6. FIG. 2 shows an enlarged view of the top of the assembly 2, and FIG. 3 shows an enlarged view of the area enclosed by the dashed rectangle C in FIG. 1.

[0040] The heat transfer plate 4, shown individually in FIG. 6, has a first side 8 shown in FIGS. 1-3 and 6 and an opposite second side 10 shown in FIGS. 4 and 5. It is an essentially rectangular stainless steel sheet with a number of portholes 12, 14, 16, and 18 stamped into different areas of the heat transfer plate in specific patterns. A gasket groove 20 extending along the outer plate edge 22 to surround the portholes 12, 14, 16, and 18 is also pressed into the first side 8 of the heat transfer plate 4, completely aligned with and separately surrounding the two inner plate edges 24, 26 that define two of the portholes 14, 18, respectively. Furthermore, the gasket groove 20 extends diagonally across the heat transfer plate twice to further surround the portholes 14, 18. The outer edge portion 28 of the heat transfer plate 4 extends between the outer plate edge 22 and the gasket groove 20, and the inner edge portions 30, 32 of the heat transfer plate 4 extend between the inner plate edge 24 and the gasket groove 20, and the portion between the inner plate edge 26 and the gasket groove 20 is corrugated to include alternating ridges 34 and valleys 36 (see Figures 2, 3, and 6 for the outer edge 28). The ridges and valleys when viewed from one side of the heat transfer plate 4 are valleys and ridges, respectively, when viewed from the other side of the heat transfer plate 4. Notably, the portholes 12, 16 are also each surrounded by a similarly corrugated inner edge.

[0041] As shown in FIGS. 4 and 5 , the peaks 38 of the ridges 34 extend in an imaginary top plane TP, and the bottom portions 40 of the valleys 36 extend in an imaginary bottom plane BP. The bottoms 42 of the gasket grooves 20 extend in an imaginary intermediate plane IP, which here extends between the top plane TP and the bottom plane BP. The intermediate plane IP may have different locations in different embodiments of the invention. In the embodiment shown in the drawings, the intermediate plane IP is located midway between the top plane TP and the bottom plane BP along the majority of the gasket groove 20. In an alternative exemplary embodiment, the intermediate plane IP may instead coincide with the bottom plane BP along the majority of the gasket groove 20.

[0042] As can be seen particularly in Figures 4-6, ridges 34 are closed toward gasket groove 20 and are configured to provide gasket support. Valleys 36 are open toward gasket groove 20, but are only partially open here because bottoms 42 of gasket groove 20 extend above bottom portions 40 of valleys 36.

[0043] 2, the outer edge 28 of the heat transfer plate 4 comprises a plurality of outer gasket fastening areas 44 distributed along the outer plate edge 22. At least some of the gasket fastening areas 44 are designed in accordance with the present invention. For completeness, it should be said that the inner edge of the heat transfer plate 4 also includes a plurality of inner gasket fastening areas distributed around the portholes 12, 14, 16, and 18. However, these are of conventional design and will not be described further herein.

[0044] One gasket fastening region 44 designed according to the present invention is shown in more detail in FIG. 6. It comprises a first valley 36a of the valley portion 36 and a first ridge 34a and a second ridge 34b of the ridge portion 34, with the first ridge 34a and the second ridge 34b located on opposite sides of the first valley 36a. Most of the ridges 34 and valleys 36 within the outer edge 28 of the heat transfer plate 4 are designed similarly to the leftmost ridge 34 and valley 36 in FIG. 6, i.e., they have essentially a constant width along their entire longitudinal extension, the width being measured parallel to the longitudinal direction or extension length of the gasket groove 20. However, this is not the case for the first valley 36a and the first ridge 34a and second ridge 34b of the gasket fastening region 44.

[0045] The first valley 36a has an axis of symmetry extending perpendicular to the outer edge 22 and includes a first portion 36a1, a second portion 36a2, and a third portion 36a3. The second portion 36a2 contacts the outer edge 22 of the heat transfer plate 4, and the third portion 36a3 contacts the gasket groove 20 of the heat transfer plate 4. The first portion 36a1 is disposed between the second portion 36a2 and the third portion 36a3. In FIG. 6, the boundaries between the first portion 36a1, the second portion 36a2, and the third portion 36a3 are indicated by dashed lines. The first portion 36a1, the second portion 36a2, and the third portion 36a3 have widths wv1, wv2, and wv3, respectively, which all vary. The second width wv2 and the third width wv3 are all smaller than the first width wv1. An inner sub-portion of the second portion 36a2 that contacts the first portion 36a1 tapers in a direction toward the outer edge 22 of the heat transfer plate 4, while an outer sub-portion of the second portion 36a2 that contacts the first portion 36a1 tapers in a direction toward the outer edge 22 of the heat transfer plate 4. The portion on the outer edge 22 has an essentially constant width. The third portion 36a3 tapers in a direction toward the gasket groove 20 of the heat transfer plate 4.

[0046] The first protrusion 34a includes a first portion 34a1, a second portion 34a2, and a third portion 34a3. The second portion 34a2 contacts the outer edge 22 of the heat transfer plate 4, and the third portion 34a3 contacts the gasket groove 20 of the heat transfer plate 4. The first portion 34a2 is disposed between the second portion 34a2 and the third portion 34a3. In FIG. 6, the boundaries between the first portion 34a1, the second portion 34a2, and the third portion 34a3 are indicated by dashed lines. The first portion 34a1, the second portion 34a2, and the third portion 34a3 have widths wr1, wr2, and wr3, respectively, which vary. The second width wr2 and the third width wr3 are all greater than the first width wr1. An inner subportion of the second portion 34a2 that abuts the first portion 34a1 tapers toward the gasket groove 20 of the heat transfer plate 4, while an outer subportion of the second portion 34a2 adjacent the outer edge 22 has an essentially constant width. The third portion 34a3 tapers toward the outer edge 22 of the heat transfer plate 4. The tapering of the second portion 34a2 and the third portion 34a3 of the first ridge 34a is achieved by the angled inner longitudinal side of the first ridge 34a. An outer longitudinal side 46 of the first ridge 34a is essentially straight and extends perpendicular to the outer edge 22 of the heat transfer plate 4.

[0047] As can be seen from FIG. 6, the second ridge 34b of the gasket fastening area 44 is designed in a similar manner as the first ridge 34a.

[0048] 1 and 2, the gasket configuration 6 comprises a rubber gasket 48 having an annular field portion 50, two annular ring portions 52, 54, and a bridge 56 connecting the ring portions 52, 54 to the field portion 50. The gasket configuration 6 further comprises a plurality of rubber attachment means 58 integrally formed with the gasket 48. The attachment means 58 are distributed along the outside of the field portion 50 of the gasket 48. At least some of the attachment means 58 are designed in accordance with the present invention. For completeness, it should be said that the gasket configuration 6 also comprises attachment means along the inside of the ring portions 52, 54 and the inside of the field portion 50. However, these are of conventional design and will not be further described herein.

[0049] One attachment means 58 designed in accordance with the present invention is shown in more detail in Figures 7 and 8. It comprises an elongated bridge 60, a connecting member 62, a first finger 64, and a second finger 66. The bridge 60 extends longitudinally, spaced apart from and generally parallel to the gasket 48. The connecting member 62 extends longitudinally from the center of the bridge 60, essentially perpendicular to the bridge 60, connecting the bridge 60 to the gasket 48. More specifically, a first connecting portion 68 in the form of one end of the connecting member 62 is connected to the gasket 48, while a second connecting portion 70 in the form of the other end of the connecting member 62 is connected to the bridge 60. The first finger 64 and the second finger 66 extend longitudinally, essentially perpendicular to the bridge 60, from each end of the bridge 60, i.e., from opposite sides of the connecting member 62, toward the gasket 48. More specifically, a connecting portion 72 in the form of one end of the first finger 64 is connected to the bridge 60, while the other end of the first finger 64 is free and spaced apart from the gasket 48. Similarly, a connecting portion 74 in the form of one end of the second finger 66 is connected to the bridge 60, while the other end of the second finger 66 is free and spaced apart from the gasket 48.

[0050] The connecting member 62 has an axis of symmetry perpendicular to the bridge 60 and extending through its center, and includes a first portion 621, a second portion 622, and a third portion 623. The second portion 622 is adjacent to the bridge 60 of the attachment means 58, the third portion 623 is adjacent to the gasket 48, and the first portion 621 is disposed between the second portion 622 and the third portion 623. In Figures 7 and 8, the boundaries between the first portion 621, the second portion 622, and the third portion 623 are indicated by dashed lines. The widths of the attachment means 58 and its components are measured parallel to the longitudinal or extended length of the gasket 48. The first portion 621, the second portion 622, and the third portion 623 have widths wc1, wc2, and wc3, respectively, which all vary. The second width wc2 and the third width wc3 are all smaller than the first width wc1. An inner sub-portion of the second portion 622 adjacent to the first portion 621 tapers in a direction toward the bridge 60 of the attachment means 58, while an outer sub-portion of the second portion 622 adjacent to the bridge 60 has an essentially constant width. The third portion 623 tapers in a direction toward the gasket 48.

[0051] Furthermore, the first finger 64 comprises a first portion 641 and a second portion 642. The second portion 642 is adjacent to the bridge 60 of the attachment means 58, and the first portion 641 is disposed between the bridge 60 and the gasket 48. In FIGS. 7 and 8, the boundary between the first portion 641 and the second portion 642 is indicated by a dashed line. The first portion 641 and the second portion 642 have widths wf1 and wf2, respectively, which vary. The second width wf2 is greater than the first width wf1. The first portion 641 and the second portion 642 taper away from the bridge 60. The taper is achieved by the inner longitudinal surface of the first finger 64 being non-perpendicular to the longitudinal direction or extension of the bridge 60. The outer longitudinal surface 76 of the first finger 64 is essentially straight and extends perpendicular to the longitudinal extension of the bridge 60. 8 and 4, the first finger 64 has a thickness that is less than the thickness of the bridge 60, the thickness being measured perpendicular to the longitudinal or extended length of the gasket 48. The connecting member 62 of the attachment means 58 has a thickness that is equal to the thickness of the bridge 60.

[0052] As is evident from FIGS. 7 and 8, the second finger 66 of the attachment means 58 is designed in a manner corresponding to the first finger 64 .

[0053] The gasket grooves 20 of the heat transfer plate 4 are configured to receive gaskets 48, as shown in Figure 1. Furthermore, the gasket fastening areas of the heat transfer plate 4 are configured to cooperate with the attachment means of the gasket arrangement 6 to fasten the gasket 48 to the heat transfer plate 4. The cooperation between one of the gasket fastening areas 44 according to the invention and one of the attachment means 58 according to the invention is shown in particular in Figures 3 to 5. It should be mentioned that in the drawings for illustrative purposes the heat transfer plate 4 is shown transparent in the gasket fastening areas.

[0054] 3 , when the attachment means 58 is properly engaged with the gasket fastening region 44, the connecting member 62 engages with the first surface 8 of the heat transfer plate 4, while the first finger 64 and the second finger 66 engage with the second surface 10 of the heat transfer plate 4. More specifically, the connecting member 62 is received in the first valley 36a, and the first finger 64 and the second finger 66 are received in the valleys defined by the first ridge 34a and the second ridge 34b, respectively. Furthermore, the bridge 60 of the attachment means 58 extends outwardly of the heat transfer plate 4 parallel to the outer edge 22 of the heat transfer plate 4. The configuration of the connecting member 62 of the attachment means 58 and the first valley 36a of the gasket fastening region 44 is complementary, such that the connecting member 62 fits tightly and substantially fills the entire first valley 36a. Due to the different widths of the connecting member 62 and the first valley 36a, they "interlock" and prevent the attachment means 58 from sliding in a direction parallel to the extension plane of the heat transfer plate 4, in particular in a direction perpendicular to the outer edge 22 of the heat transfer plate 4. This achieves a secure fixation of the gasket 48 to the heat transfer plate 4.

[0055] A gasketed plate heat exchanger may include a compressed stack of heat transfer plates 4 and a gasket arrangement 6 disposed between each of the adjacent heat transfer plates 4. Referring to the background art section, when the heat transfer plates 4 are arranged "rotated" relative to one another, the gasket arrangement 6 is disposed and fixed on the first surface 8 of the heat transfer plate 4, as described above. The heat transfer plates 4 with the gasket arrangement 6 are then stacked back-to-back, with every other heat transfer plate 4 upside down relative to the remaining heat transfer plates. On the other hand, when the heat transfer plates 4 are arranged "inverted" relative to one another, the gasket arrangement 6 is disposed and fixed on every other first surface 8 of the heat transfer plate 4 and on the second surface 10 of the remaining heat transfer plates 4. The heat transfer plates 4 with the gasket arrangement 6 are then stacked back-to-back and face-to-face, with every other heat transfer plate upside down relative to the remaining heat transfer plates. To allow gasketing also on the second face 10 of the heat transfer plate 4, the edge 28 of the heat transfer plate 4 also comprises an "inverted" gasketing area 78, as shown most clearly in FIG.

[0056] 9 shows another attachment means 58 of a gasket arrangement 6 also designed in accordance with the present invention. The attachment means of FIG. 9 is similar to the attachment means shown in the remainder of the drawings, and the above description is also applicable to the attachment means of FIG. 9, with the following exceptions: bridge 60 does not extend longitudinally parallel to gasket 48, connecting member 62 does not have an axis of symmetry, and the outer sub-portion of third portion 623 of connecting member 62 adjacent first portion 621 tapers in the direction toward gasket 48, while the inner sub-portion of third portion 623 of connecting member 62 adjacent gasket 48 has an essentially constant width.

[0057] The above-described embodiments of the present invention should be considered as examples only, and it will be understood by those skilled in the art that the described embodiments can be modified in various ways without departing from the concept of the present invention.

[0058] As an example, the first and second fingers of the connecting member and attachment means, i.e., the first valley and first and second ridges of the gasket fastening region, need not be partially or completely tapered to change their width. For example, the width change may be more abrupt and instantaneous, occurring in steps rather than gradually. Accordingly, one or more of the first, second, and third widths referenced above may be constant and unchanging. Thus, the fingers may also have a constant width along a portion of their length.

[0059] As another example, the fingers and / or connecting members need not extend parallel to one another and / or perpendicular to the bridge, and thus the first valley and the first and second ridges need not extend longitudinally parallel to one another and perpendicular to the outer plate edge.

[0060] The above-described electric heating plate has the gasket fastening regions of the present invention arranged along the outer plate edge and along the two opposing long sides of the electric heating plate. Thus, the above-described gasket configuration has the attachment means of the present invention arranged along the two opposing long sides of the field portion of the gasket and protruding from the outside thereof. Naturally, the gasket fastening regions of the present invention may also / alternatively be arranged along the two opposing short sides of the heat transfer plate and / or along the inner plate edge, i.e., around the portholes of the heat transfer plate. Thus, the attachment means of the present invention may be arranged along the two opposing short sides of the field portion of the gasket and / or along the ring portion protruding from the inside of the gasket.

[0061] The mounting means of the present invention may include two or more connecting members configured to connect the bridge of the mounting means to the gasket, and two or more fingers configured to extend from the bridge of the mounting means toward the gasket. The electric heating plate may have a gasket fastening area designed to cooperate with such mounting means.

[0062] The mounting means need not be designed such that, when properly engaged with the heat transfer plate, the bridge of the mounting means is positioned outside the heat transfer plate. Instead, the bridge can be designed to be at least partially positioned within the heat transfer plate, possibly engaging the first and / or second surfaces of the heat transfer plate, when the mounting means properly engages the heat transfer plate. The electric heat plate can have a gasket fastening area designed to cooperate with such mounting means.

[0063] The connecting members of the attachment means described above extend from the bridge to the gasket, but may instead extend beyond the bridge and / or the gasket. Similarly, the fingers may extend beyond the bridge and / or the gasket. The electric heating plate may have a gasket fastening area designed to cooperate with such attachment means.

[0064] The gasket and the attachment means do not have to be integrally formed but can be two separate connectable parts. Furthermore, the gasket and the attachment means do not have to be made of rubber but can be made of any suitable material. Furthermore, the gasket and the attachment means do not have to be the same material.

[0065] The heat transfer plates need not be made of stainless steel, but may be made of any suitable material such as titanium or aluminum.

[0066] Finally, the present invention may be used in combination with other types of plate heat exchangers than purely gasketed ones, for example plate heat exchangers that include permanently bonded heat transfer plates.

[0067] It is emphasized that the terms first, second, third, etc., are used herein only to distinguish between attributes of the same species and do not express any kind of mutual ordering between species.

[0068] It should be emphasized that details not relevant to the present invention have been omitted and that the drawings are merely schematic and not drawn to scale. It should also be noted that some drawings are simplified more than others. Thus, some elements may be shown in one drawing but omitted in another. [Explanation of symbols]

[0069] 4 Heat transfer plates 6 Gasket configuration 8 First Side 8 10 Second Side 10 12, 14, 16, 18 portholes 20 Gasket groove 22 outer plate edge 24, 26 Inner plate edge 28 outer edge 30, 32 Inner edge 34 Ridge 34a First Bump 34b Second Bump 36 Valley 36a First Valley 38 Top 40 Bottom part 44 Gasket fastening area 48 Rubber gasket 50 Circular field section 52, 54 Annular ring portion 56, 60 Bridge 58 Mounting means 62 Connecting member 64 First Finger 66 Second Finger 76 Longitudinal surface BP Virtual bottom IP Virtual Midplane TP Virtual Top

Claims

1. Attachment means (58) for fixing a gasket (48) to a heat transfer plate (4), the attachment means (58) comprising a connecting member (62), a first finger (64), a second finger (66), and a bridge (60), wherein a first connecting portion (68) of the connecting member (62) is configured to engage with the gasket (48), a second connecting portion (70) of the connecting member (62) engages with the bridge (60), a connecting portion (72) of the first finger (64) engages with the bridge (60), and a connecting portion (74) of the second finger (66) engages with the bridge (60), the first finger (64) and the second finger (66) are configured to extend from the bridge (60) toward the gasket (48), and the connecting member (62) extends between the first finger (64) and the second finger (66). The connecting member (62) comprises a first portion (621) having a first width (wc1), a second portion (622) having a second width (wc2), and a third portion (623) having a third width (wc3), the first portion (621) being disposed between the second portion (622) and the third portion (623), the second portion (622) being disposed closer to the bridge (60) than the first portion (621), and the second width (wc2) and the third width (wc3) being smaller than the first width (wc1).

2. 2. The attachment means (58) of claim 1, wherein the second portion (622) of the connecting member (62) tapers along at least a portion of its length in a direction toward the bridge (60).

3. Attachment means (58) according to claim 1, wherein the third portion (623) of the connecting member (62) is tapered away from the bridge (60) along at least a portion of its length.

4. 3. The attachment means (58) according to claim 1 or 2, wherein the first finger (64) comprises a first portion (641) having a first width (wf1) and a second portion (642) having a second width (wf2), the second portion (642) being positioned closer to the bridge (60) than the first portion (641), and the first width (wf1) being smaller than the second width (wf2).

5. 5. The attachment means (58) of claim 4, wherein the second portion (642) of the first finger (64) is tapered away from the bridge (60) along at least a portion of its length.

6. 3. The attachment means (58) of claim 1 or 2, wherein the outer longitudinal surface (76) of the first finger (64) extends substantially straight and substantially perpendicular to the extended length of the bridge (60).

7. 3. The attachment means (58) of claim 1 or 2, wherein the thickness of the bridge (60) is greater than the thickness of the first finger (64).

8. A heat transfer plate (4) comprising: a gasket groove (20) on a first surface (8) of the heat transfer plate (4) extending along an edge (22) of the heat transfer plate (4); and an edge portion (28) of the heat transfer plate (4) extending between the edge (22) of the heat transfer plate (4) and the gasket groove (20), the edge portion (28) of the heat transfer plate (4) being corrugated to have alternating ridges (34) and valleys (36) when viewed from the first surface (8) of the heat transfer plate (4), the edge (28) comprises a gasket fastening area (44) configured to engage with an attachment means (58) for securing a gasket (48) in the gasket groove (20), the gasket fastening area (44) comprising a first valley (36a) of the valley portion (36) and a first ridge (34a) and a second ridge (34b) of the ridge portion (34), the first ridge (34a) and the second ridge (34b) being disposed on either side of the first valley (36a); The heat transfer plate (4), wherein the first valley (36a) includes a first portion (36a1) having a first width (wv1) and a second portion (36a2) having a second width (wv2), the second portion (36a2) being positioned closer to the edge (22) than the first portion (36a1), and the second width (wv2) being smaller than the first width (wv1).

9. 9. The heat transfer plate (4) according to claim 8, wherein the second portion (36a2) of the first valley (36a) tapers along at least a portion of its length in a direction towards the edge (22).

10. 10. The heat transfer plate (4) according to claim 8 or 9, wherein the first valley (36a) further includes a third portion (36a3) having a third width (wv3), the first portion (36a1) of the first valley (36a) being disposed between the second portion (36a2) and the third portion (36a3) of the first valley (36a), and the third width (wv3) being smaller than the first width (wv1).

11. 11. The heat transfer plate (4) according to claim 10, wherein the third portion (36a3) of the first valley (36a) tapers along at least a portion of its length in a direction away from the edge (22).

12. 10. The heat transfer plate (4) according to claim 8 or 9, wherein the first protrusion (34a) includes a first portion (34a1) having a first width (wr1) and a second portion (34a2) having a second width, the second portion (34a2) being positioned closer to the edge (22) than the first portion (34a1), and the first width (wr1) being smaller than the second width (wr2).

13. 13. The heat transfer plate (4) according to claim 12, wherein the second portion (34a2) of the first ridge (34a) tapers along at least a portion of its length in a direction away from the edge (22).

14. 10. The heat transfer plate (4) according to claim 8 or 9, wherein the outer longitudinal surface (46) of the first ridge (34a) is substantially straight and extends substantially perpendicular to the edge (22) of the heat transfer plate (4).

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