EP2045557B1 - Plate heat exchanger - Google Patents

Abstract

The plate heat exchanger has a number of plates (1,1') positioned one after the other for forming a stack, with alternating closed channels for a heat dissipation medium and a heat reception medium formed by elastic seals (4) inserted between the adjacent plates. The seals have integral elastic nipples (25) fitted in holes (26) in the plates, each nipple having a cross-section which is less than the cross-section of the hole, but projecting beyond its periphery at several points.

Description

The present invention relates to a plate heat exchanger, consisting of successively arranged, connected to a package plates according to the preamble of claim 1.

Before the plates of a plate heat exchanger are suspended in a rack and compressed into a package, the seals in the grooves are defined, which facilitates the handling of the plates during assembly. A known way of attaching the seals is that they are glued into the groove, the adhesive for the sealing effect itself does not matter, but the positionally correct fixation on the plates is used. This adhesive technique has some disadvantages. So must the grooves before applying the adhesive z. B. are cleaned of oil and fat residues, so as not to affect the adhesive effect. Then the adhesive itself must be applied. This is quite time-intensive. Problems also occur in the maintenance of plate heat exchangers when a gasket must be replaced. To do this, remove the old seal and then clean the groove of the adhesive. Also, an inspection of the groove bottom and the seal, z. B. after cleaning work on the disassembled heat exchanger, is only possible if previously the adhesive bond is destroyed.

Due to these disadvantages and the fact that in some technical fields, such. As the medical and food industry adhesives are to be avoided as possible, plate heat exchangers have been developed in which the seals mechanically, ie without adhesive to the plates be attached. One known method in the art for adhesive seal attachment is to integrally form seals with the elastic nipples or projections press fit with associated holes or openings in the plates.

To GB 2 071 303 A . GB 2 075 656 A and EP 0 134 155 A1 should the nipples over the holes have such an oversize that they can easily be pressed into the holes and pulled out again. It should be ensured that the seal is securely fixed in place. This solution brings with it problems, since the nipples and the seal as castings are subject to tolerance variations. Too much radial excess of the nipples can be very difficult or not pressed into the holes. If this still succeeds, the nipples tear when removing the seal, z. As in inspection or cleaning, from, so that the seal must be replaced by a new seal.

The problem of tolerances in the radial nipple dimensions is determined by a in the EP 0 039 229 A2 solved proposed plate heat exchanger. Here, the nipples are arranged on the side of the seal, integrally provided with this webs provided, of which project the nipple down. Through the webs through a blind hole leads into the nipple. To secure the seal, the nipples are positioned above their associated holes on the plates. Then a pin or similar tool is inserted into the blind hole and the nipples are then stretched by pressure on the pin, so that they are much thinner and can be easily inserted into the holes. After removing the pin, the nipples retract to their original dimensions, expanding the ends of the nipples inserted through holes into a head covering the hole from below. The seals are thus securely attached to the plates. A disadvantage of this technique is that for pressing the nipple tool is required. Furthermore occur during inspections or maintenance that requires removal of the seal, follow the above described consequences.

From the EP 0 123 379 B1 Finally, a plate heat exchanger is known in which the seal is secured by means integrally formed with her elastic projections which engage in associated openings in the groove base to the plate. The apertures are formed to have a male and an extraction region into which the projections are free to move freely in and out of the edge of the apertures. From this area, the projections are transferable into a blocking area of the openings, in which the movement of the projections into the openings in and out of these again strong resistance by pressing between the projections and the edges of the openings is opposite, wherein the convertibility of the projections the insertion and withdrawal position in the locked position and vice versa due to the elasticity (compliance) of the seal is possible.

Object of the present invention is to provide a simple solution for the mechanical attachment of the seals on the plates in a plate heat exchanger of the generic type, yet allows a secure fit and easy removal of the seals.

This object is achieved by a plate heat exchanger with the features of claim 1.

In a plate heat exchanger according to claim 1, the object is achieved in that the edge of the holes is formed as a pointing in the insertion direction of the nipple passage. This design of the holes has several advantages. So on the one hand the contact surface between nipple and hole is increased. As a result, the radial excess of the nipples required by the prior art can be reduced while maintaining a secure hold of the seal. The nipples are thereby easier to push into the holes and pull out. On the other hand, the immersion of the nipples is facilitated in the holes, since the ends of the nipple run when inserted into the holes against a circumferential radius at the edge of the hole, which automatically results in the production of the passage. This radius also makes it possible to provide a radius at the transition from the nipple to the seal. This has on the one hand manufacturing advantages in making the seal and on the other hand it reduces the risk that the nipples are sheared at plate movements at this point.

In an embodiment of the invention according to claim 1, the nipples have a cross section which is smaller than the passage cross section of the holes, but this projects beyond several points on the circumference. In this case, the nipples can have a polygonal cross section and the holes can have a circular cross section or, conversely, the holes can have a polygonal passage cross section and the nipples can have a circular cross section. Due to this development of the invention, the nipples are not pressed on their entire circumference when they are plugged into the holes, but only locally at the points where they project beyond the edge of the holes. Since their cross section is smaller than the passage area of the holes, in the other places is still play between the circumference of the nipples and the edge of the holes. Due to the elasticity of the nipples whose pressed material can escape into these spaces, resulting in a reduction of the pressure and thus facilitates the pressing of the nipple in the holes. This displacement mechanism is advantageous in the enlarged by the passages contact area between nipple and hole edge, as it has a greater creative freedom in optimizing the exchange ratio of passage area and radial excess of nipples or in other words, in the optimization of the target variables - secure hold and easy removal the seal - creates.

Fig. 1

eine schematische Draufsicht auf eine Platte eines Platten- wärmetauschers,

Fig. 2

einen ausschnittsweisen perspektivischen Blick auf den Randbereich einer Platte mit eingelegter Dichtung,

Fig. 3

eine Schnitt A-A gemäß Fig. 2 im vergrößerten Maßstab mit zusätzlicher Darstellung einer aufgelegten, zweiten Platte mit eingelegter Dichtung,

Fig. 4

einen Schnitt B-B gemäß Fig. 2 im vergrößerten Maßstab, ebenfalls mit zusätzlicher Darstellung einer aufgelegten zwei- ten Platte mit eingelegter Dichtung,

Fig. 5

einen Schnitt C-C gemäß Fig. 2 im vergrößerten Maßstab, ebenfalls mit zusätzlicher Darstellung einer aufgelegten zwei- ten Platte mit eingelegter Dichtung,

Fig. 6

einen Schnitt D-D gemäß Fig. 5 im vergrößerten Maßstab, und

Fig. 7

einen Schnitt E-E gemäß Fig. 5 im vergrößerten Maßstab.

The invention will be explained in more detail below with reference to an embodiment and an accompanying drawing. In this drawing shows:

Fig. 1

a schematic plan view of a plate of a plate heat exchanger,

Fig. 2

a partial perspective view of the edge region of a plate with inlaid seal,

Fig. 3

a section AA according to Fig. 2 on an enlarged scale with additional representation of an applied, second plate with inserted seal,

Fig. 4

a section BB according to Fig. 2 on an enlarged scale, also with additional representation of an applied second plate with inserted seal,

Fig. 5

a section CC according to Fig. 2 on an enlarged scale, also with additional representation of an applied second plate with inserted seal,

Fig. 6

a section DD according to Fig. 5 on an enlarged scale, and

Fig. 7

a section EE according to Fig. 5 on an enlarged scale.

Fig. 1 shows a plate 1 of a plate heat exchanger with a heat exchange surface 2 which is framed by an inserted in a peripheral groove 3 seal 4 made of synthetic rubber or other elastic sealing material. At the corners of the plate 1, inlet and outlet openings 5-8 are provided for the heat exchange media. While in the illustrated plate 1, the inlet and outlet openings 5, 6 are enclosed by the gasket 4, the gasket surrounds in front of and behind the plate 1, arranged in Fig. 1 plates not shown, the inlet and outlet openings 7 and 8. In this way, alternately formed between the bundled into a package plates flow channels for a heat-emitting and a heat-absorbing media. In this respect, the plate heat exchanger corresponds to the known from the prior art structure, so that no further explanation is required for this purpose.

The gasket 4 is fixed in the groove 3 without using any adhesive. For this purpose, on the side facing away from the heat exchanger surface 2 integrally formed with the seal 4 holding parts 9 are provided, which are arranged at suitable intervals from each other on the circumference of the seal 4 and laterally protrude from this.

Such a holding part 9 is in Fig. 2 shown in perspective, which shows a marginal detail of the plate 1. At this point it should be mentioned that in the illustration according to Fig. 2 a second plate 1 ', which in the sectional views according to the Fig. 3-5 is apparent, has been omitted for clarity.

Out Fig. 2 shows that the groove 3 from a sloping from the level of the heat exchange surface 2 Innen.Seitenwand 10, a groove bottom 11 and a back to the level of the heat exchange surface 2 rising outer side wall 12 is formed, with a plate edge 13 connects to the latter. This plate edge 13 is not flat, but formed by alternately up and down and outward opening in cross-section trapezoidal channels 14 and 15. The bottoms 16 of the channels 14 are at the level of Nutenbodens 11 and the bottoms 17 of the channels 15 at the level of the heat exchange surface 2. This "corrugation" of the plate edge 13 is formed by the fact that the channels 14 from the sheet metal plate of the plate 1 as to the groove 3 closed troughs are pushed down. As a result, remain between the end walls 18 of the channels 14 and the outer side wall 12 of the groove 3 bridges 19 are. The cavities 20 formed below these bridges 19 connect the channels 15, which pass through to the outer side wall 12 of the groove 3, on the underside of the plate first

Each holding part 9 engages in each case in two adjacent channels 14 and an intermediate channel 15 a. It is connected via an over its entire width extending web 21 with the seal 4, which incorporates into the upper edge of the seal 4. The shape of this web 21 is off Fig. 2 not apparent, but opens from a synopsis of the cross-sectional views according to the 3 and 4 , It follows that the web 21 is thinner in the region of the bottom 17 of the channel 15, as in the region of the bridges between the two channels 14 and the outer side wall 12 of the groove 3, ie, the web 21 is reinforced in these areas. To accommodate these reinforced areas of the web 21, the bridges of the channels 14, in which the holding part 9 engages, pressed down in comparison to the other bridges 19 by the amount of reinforcement down, so that the bridges 19.1 formed thereby have a lower height as the bridges 19. This training, in turn, results from a synopsis of the 3 and 4 ,

The web 21 is followed by two extensions 22, which are connected to each other at their end facing the seal 4 by a cross member 23, to which, based on the plate edge 13, outwardly a thinner, the extensions 22 also connecting intermediate part 24 connects whose underside forms an extension of the web 19.

When installed, the projections 22 are located in the associated channels 14, while the intermediate piece 24 rests on the bottom 17 of the channel 15 arranged therebetween. As in particular from Fig. 5 As can be seen, the cross-section of the projections 22 is selected so that they completely through the channels 14 of the plate 1 and the channels 15 of the behind or arranged on the drawing, overlying plate 1 ', hexagonal cross-section completely fill, in other words , They lie positively in the associated, facing each other channels 14 and 15. Since the channels 14, 15 to the outside, so the environment are open, the holding parts 9 can expand in this direction, whereby thermal and mechanical stresses degraded, and thus deformations the plate edge 13 can be avoided.

Out Fig. 5 combined with Fig. 3 shows that the bottom 16 of the channel 14 of the plate 1 ', which is located above the intermediate part 24, is raised in the rear region by the thickness of the intermediate part 24, that is, it nestles in a sense from above to the intermediate part 24. Out Fig. 3 It can also be seen that the cross member 23 substantially fills the cavity 20 formed under the bridge 19 in the assembled state.

The described positive formation of the holding parts 9 with the plates 1, 1 'covering them stabilizes the alignment of the plates 1, 1' in the plate pack and prevents or reduces movements in cooperation with conventional metallic guide elements formed on the plates the plates 1, 1 'in the plane of the plate in operation due to the internal pressure of the heat exchange media.

Since the holding parts 9 and thus also the seal 4 in the embodiment described so far rest only loosely on the plate 1, provisions for attachment must be made so that the seal 4 is securely fixed in the groove 3 during assembly when handling it in front. For this purpose, an integrally formed with the holding part 9 nipple 25 is provided, which protrudes from the intermediate part 24 down and protrudes when mounted seal 4, a circular hole 26 in the plate 1. The edge of this hole 26 is formed as a passage 27 in the insertion direction of the nipple 25. The radius formed at the hole edge due to the passage 27 facilitates the insertion of the nipple 25 into the hole 26. At the same time, the transition of the nipple 25 to the intermediate part 24 can also be carried out with this radius. This training reduces on the one hand acting on the nipple 25 from the edge of the hole 26 shearing forces and facilitates the other production, since radii can be better realized in a mold. To further facilitate the insertion into the hole 26, the tip of the nipple 25 is frustoconical.

The nipple 25 is different from. Circular cross section of the hole 26 has a trigonal cross section, wherein the edges 29 are rounded. This training is best Fig. 6 out. In this illustration, a nipple cross-section enclosing circle 28 is located. The diameter D1 of this circle 28 is greater than the inner diameter D2 of the hole 26. At the same time, however, the cross-sectional area of the nipple 25 is smaller than the passage cross-section of the hole 26.

If the nipple 25 is pressed in the assembly of the seal 4 in the hole 26, so he centers himself due to its conical tip and the radius of the hole edge itself. At the same time its penetration into the hole 26th facilitated. Upon further impressions of the nipple 25, its material is compressed to the over the inner diameter of the hole 26 protruding positions, which are in this case the rounded edges 29, together. But it can escape because of its elasticity in the free spaces between the cross section of the nipple 25 and the hole inner wall. In Fig. 7 These free spaces are provided with the reference numeral 30. Since the material of the nipple 25 thus has freedom of movement radially and axially, the indentation and withdrawal of the nipple 25 in and out of the hole 26 is facilitated. At the same time, provision is made for the required nippling fit of the nipple 25 in the hole 26, which is further enhanced by the larger inner wall surface of the hole 26 created by the passage 27.

Claims (5)

1. Plate heat exchanger consisting of plates arranged in succession and connected to form a unit which, by means of a resilient seal inserted in each case between two adjacent plates into a peripheral groove, form sealed channels alternately for a heat-dissipating medium and a heat-absorbing medium, which may be loaded with the respective medium via inlet and outlet openings of the plates aligned with one another, the seals in each case being mechanically fastened to one of the plates which seal them relative to one another by resilient nipples which are formed integrally with the seals and arranged at intervals on the longitudinal extension thereof being pressed into associated holes of the plates, characterised in that the edge of the holes (26) is formed as a downturned edge (27) facing in the direction of insertion of the nipples (25).
2. Plate heat exchanger according to Claim 1, characterised in that the nipples (25) have a cross section which is smaller than the passage cross section of the holes (26) but protrudes over said holes at a plurality of points on the periphery.
3. Plate heat exchanger according to Claim 2, characterised in that the nipples (25) have a polygonal cross section and the holes (26) have a circular cross section.
4. Plate heat exchanger according to Claim 2, characterised in that the holes (26) have a polygonal passage cross section and the nipples (25) have a circular cross section.
5. Plate heat exchanger according to one of the preceding claims 1 to 4, characterised in that the tip of the nipples (25) is of conical shape.

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