PLATE HEAT EXCHANGER

Abstract

A plate heat exchanger is described comprising a plurality of heat transfer plates 10 stacked on top of each other, wherein gaskets are positioned between adjacent heat transfer plates 10, wherein each gasket is arranged in a gasket groove 20 formed in a heat transfer plate 10 and a bottom part of the gasket groove 20 defines a base level 22, wherein the gasket groove 20 comprises a reinforcing pattern having a first recess 23 at a first recess level and extending in a lengthwise direction of the gasket groove 20. A plate heat exchanger should allow higher pressures without increasing the risk of leakages. To this end the reinforcing pattern comprises a second recess 25 at a second recess level extending in lengthwise direction of the gasket groove 20.

Claims

1. A plate heat exchanger comprising a plurality of heat transfer plates stacked on top of each other, wherein gaskets are positioned between adjacent heat transfer plates, wherein each gasket is arranged in a gasket groove formed in a heat transfer plate and a bottom part of the gasket groove defines a base level, wherein the gasket groove comprises a reinforcing pattern having a first recess at a first recessed level and extending in a lengthwise direction of the gasket groove, wherein the reinforcing pattern comprises a second recess at a second recess level extending in lengthwise direction of the gasket groove.

2. The plate heat exchanger according to claim 1, wherein the base level is defined by a bottom of the gasket groove in an edge part running along an edge of the heat transfer plate.

3. The plate heat exchanger according to claim 1, wherein the second recess extends in a direction opposite to the first recess from the first recess.

4. The plate heat exchanger according to claim 3, wherein a first portion of the gasket groove surrounds an opening of the heat transfer plate, wherein the first portion comprises the two parallel recessed parts at the first recess level.

5. The plate heat exchanger according to claim 3, wherein the gasket groove comprises a second part running diagonal to an edge portion of the heat transfer plate and being connected to the first portion.

6. The plate heat exchanger according to claim 5, wherein the second part extends into the edge part.

7. The plate heat exchanger according to claim 1, wherein the second recess extends from the first recess.

8. The plate heat exchanger according to claim 1, wherein the first recess comprises a first height and the second recess comprises a second height, wherein the first height is different from the second height.

9. The plate heat exchanger according to claim 1, wherein the heat transfer plate comprises corrugations having troughs and crests, wherein the troughs continue into the gasket groove.

10. The plate heat exchanger according to claim 9, wherein at least one of the recesses continues into the troughs.

11. The plate heat exchanger according to claim 1, wherein the first recess and the second recess extend in different directions from the base level.

12. The plate heat exchanger according to claim 11, wherein the first recess runs along a first section of the gasket groove and the second recess runs along a second section of the gasket groove, wherein the first section is different from the second section.

13. The plate heat exchanger according to claim 12, wherein the first section is arranged in one half of the heat transfer plate and the second section is arranged in the other half of the heat transfer plate.

14. The plate heat exchanger according to claim 13, wherein at least one recess reaches into the edge part of the gasket groove.

15. The plate heat exchanger according to claim 2, wherein the second recess extends in a direction opposite to the first recess from the first recess.

16. The plate heat exchanger according to claim 2, wherein the second recess extends from the first recess.

17. The plate heat exchanger according to claim 3, wherein the second recess extends from the first recess.

18. The plate heat exchanger according to claim 4, wherein the second recess extends from the first recess.

19. The plate heat exchanger according to claim 5, wherein the second recess extends from the first recess.

20. The plate heat exchanger according to claim 6, wherein the second recess extends from the first recess.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0022] A preferred embodiment of the invention will now be described in more detail with reference to the drawing, wherein:

[0023] FIG. 1 is a side view of a plate heat exchanger,

[0024] FIG. 2 is a top view of a stack of heat transfer plates,

[0025] FIG. 3 shows the problem in an area surrounding an opening of a heat transfer plate,

[0026] FIG. 4 shows a heat transfer plate from the underside,

[0027] FIG. 5A shows a groove in an area running along an edge, shown in FIG. 2,

[0028] FIG. 5B shows a section along line B according to FIG. 4,

[0029] FIG. 5C shows a section along line C of FIG. 4,

[0030] FIG. 5D shows a sectional view along line D in FIG. 4, and

[0031] FIG. 6 shows a bottom view of another heat transfer plate.

DETAILED DESCRIPTION

[0032] FIG. 1 shows schematically a heat exchanger 1 comprising a number of heat transfer plates 10 which are stacked one on top of the other. The stack of heat transfer plates is arranged between a top plate 4 and a bottom plate 5.

[0033] The heat exchanger 1 comprises four openings for inlet and outlet of the fluids. Two openings 2, 3 which are shown in FIG. 1 are used for the fluid passing the primary side of the heat exchanger 1. Two other openings 6, 7 (FIG. 2 only) are used for inlet and outlet of the fluid passing the secondary side of the heat exchanger.

[0034] FIG. 2 schematically shows a stack of four heat transfer plates 10. The heat transfer plates 10 are laterally offset to each other in order to show some details.

[0035] Each heat transfer plate 10 is provided with a gasket 8. The gasket 8 in all heat transfer plates runs along an edge 9 of the heat transfer plates. However, in a half of the number of the heat transfer plates 10 the gasket 8 leaves open a connection between the openings 2, 3 and an interior of the space between two adjacent plates for the primary side and (which is not visible in FIG. 2) in the other half, i.e. in every second plate the gasket 8 leaves open a connection between the openings 6, 7 and the interior of the space between adjacent plates 10 to allow a flow of fluid through the secondary side of the heat exchanger.

[0036] The gasket 8 is mounted in a groove.

[0037] As can be seen in FIG. 2, each heat transfer plate 10 comprises a part 11 of the groove, which is not filled by the gasket. Accordingly, the bottom of the part 11 of the groove which is free of the gasket 8 is not supported against a pressure acting between adjacent heat transfer plates. This can lead to a deformation of the heat transfer plate in the region of the part 11 of the groove with a resulting leakage. It can also lead to the effect that the gasket 8 is pushed out of position by the pressure in these areas.

[0038] This effect is schematically shown in FIG. 3 in which a gap 12 has appeared between the gasket 8 and the bottom side of the bottom of the part 11 of the groove of the next plate 10 above the gasket 8.

[0039] To overcome this problem, the heat transfer plate 10 of the heat exchanger 1 is provided with a reinforced groove 20 which is shown in several sectional views in FIG. 5. The sections are taken from a heat transfer plate 10 shown in FIG. 4. FIG. 4 shows the heat transfer plate 4 from the underside.

[0040] FIG. 5A shows the groove 20 in an area running along the edge 9.

[0041] The groove 20 comprises a bottom 21 which defines a base level. The base level 22 is shown in FIG. 5B to 5D with a dotted line.

[0042] As can be seen in FIG. 5B, showing a section along line B according to FIG. 4, groove 20 comprises a first recess comprising two parallel recessed parts 23, 24. These recessed parts 23, 24 have a first recess level which is below the base level 22. The recessed parts 23, 24 are separated by a second recess 25 extending from the bottom of the first recess in opposite direction to the first recess.

[0043] FIG. 5C shows a section along line C of FIG. 4 and shows a first recess 20 at a first recess level below the base level 22 and a second recess 25 at a second recess level below the first recess level of the first recess 23.

[0044] The first recess 23, 24 and the second recess 25 run along the lengthwise direction of the gasket groove 20.

[0045] FIG. 5D shows a sectional view along line D in FIG. 4.

[0046] It can be seen in FIG. 4 that the heat transfer plate 10 comprises corrugations having crests 26 and troughs 27. It should be noted that FIG. 4 shows the heat transfer plate 10 from the bottom so that crests 26 and troughs 27 appear to be inverted.

[0047] The groove 20 extends into the crests 27 and the first recess 23 extends into the troughs 27 as well.

[0048] As can be seen, in particular in FIG. 4, a gasket groove 20 surrounds an opening 2 of the heat transfer plate 10, wherein the form of the gasket groove 20 in this area is shown in FIG. 5B, i.e. the gasket groove 20 comprises two first recesses 23, 24 extending below the base level 22 to the first recess level.

[0049] FIG. 6 shows a slightly modified heat transfer plate 10 from the bottom, in which the gasket groove 20 comprises the ring-shaped part 28 surrounding the opening 2 and a diagonal part 29. The diagonal part 29 extends into an edge part 30 of the groove. A first recess 23 extends at least partly as well in the edge part 30 of the groove.

[0050] As can be seen in FIG. 5C, the first recess 23 comprises a first height and the second recess comprises a second height. The first height is different from the second height. In the example shown in FIG. 5C the second height is smaller than the first height. However, it is also possible that the first height is smaller than the second height.

[0051] As shown in the figures, it is also possible that the first recess 23 extends downwardly from the base level 22 in a first section of the gasket groove 20. This is shown in FIG. 5B to 5D. In a way not shown, the second section of the gasket groove 20 can have a second recess extending upwardly from the base level 22. When heat transfer plates 10 are stacked above each other, then a gasket 8 arranged in a gasket groove 20 is compressed more intensively, since the space available for the gasket 8, more precisely the height, has been decreased.

[0052] This is in particular the case, when the first section is arranged in one half of the heat transfer plate 10 and the second section is arranged in the other half of the heat transfer plate 10 and every second heat transfer plate 10 is rotated by 180 before stacking it to the previous plate 10.

[0053] While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.