US3792730A

US3792730A - Plate heat exchanger

Info

Publication number: US3792730A
Application number: US00340044A
Authority: US
Inventors: J Andersson
Original assignee: Alfa Laval AB
Current assignee: Alfa Laval AB
Priority date: 1972-03-14
Filing date: 1973-03-12
Publication date: 1974-02-19
Anticipated expiration: 1991-02-19
Also published as: IT983526B; JPS5120744B2; JPS48102345A; DE2309743A1; GB1386578A; FR2175956A1; SU502614A3; SE361356B; FR2175956B1; DE2309743C3; DE2309743B2; CA976150A

Abstract

The distribution surface of each heat exchange plate has furrows and ridges extending between the inlet opening and the main heat exchanging surface of the plate. A gasket groove adjacent the distribution surface has a side wall formed by one of the ridges and merging into the bottom of the gasket groove along a continuous line. The side of this one ridge remote from the groove is provided with recesses forming extensions of the bottom of the furrow next to this ridge, these extensions being in the direction toward the gasket groove and being aligned with the regions where said furrow bottom is supported by the ridges of the adjacent plate. The latter ridges extend sufficiently to engage these extensions of the furrow bottom, thereby lending support to the bottom of the gasket groove.

Description

United States Patent 1191 Andersson 1 1 Feb. 19, 1974 [54] PLATE HEAT EXCHANGER 3,661,203 5/1972 Mesher 165/167 [75] Inventor: .zx'ictrlilders Andersson, Lund, Primary Examiner Al Lawrence Smith Assistant ExaminerTheophi1 W. Streule, Jr. [73] Assignee: Alia-Laval AB, Tumba, Sweden 22 Filed: Mar. 12, 1973 [571 ABSTfRACT The distribution surface 0 each heat exchange plate [21] Appl 340044 has furrows and ridges extending between the inlet opening and the main heat exchanging surface of the [30] Foreign Application Priority Data plate. A gasket groove adjacent the distribution sur- Mar 14 1972 Sweden 7 4 3206/72 face has a side wall formed by one of the ridges and merging intothe bottom of the gasket groove along a 52 us. Cl. 1'6'5/167 whhhuous The Side Of this one ridge remote [51] Int. Cl F28f 3/08 from the groove is Provided with recesses forming [581 Field of Search 165/166 167 tehsihhsofthe hQhom hhmw this ridge,

7 these extensions being in the direction toward the gas- [56] References Cited ket groove and being aligned with the regions where UNITED STATES PATENTS said furrow bottom is supported by the ridges of the I adjacent plate. The latter ridges extend sufficiently to 2,814,469 11/1957 Hytte 165/167 engage these extensions of the furrow bottom, thereby 5522 ct lending support to the bottom of the gasket groove. 3:532Z161 10 1970 Lockelu: 165 167 5 Claims, 8 Drawing Fi ures PATENTED FEB I 9 I974 SHEET 1 0F 3 PATENTED FEB 1 9 i974 SHEET 2 BF 3 PATENTEDFEB 1 91974 SHEET 3 OF 3 27} 30a 21b 22a m K v 1 I Fi .7 22a PLATE HEAT EXCHANGER THE DISCLOSURE The present invention relates to plate heat exchangers of the type in which each plate has a distribution surface with furrows and ridges which extend between the inlet opening and the main heat exchanging surface of the plate, the plate being provided with a gasket groove situated adjacent the distribution surface and which has a side wall formed by one of the ridges and merging into the bottom of the gasket groove along a continuous line, so that this one ridge continuously supports a gasket in the groove. Also, the ridges of each plate cross and abut the ridges between the furrows on the opposing side of an adjacent plate, but without extending so far that they support the bottom of the gasket groove of the latter plate.

The principal object of the present invention is to provide a plate heat exchanger of this type wherein the plates have an improved arrangement for lending support to the bottoms of these gasket grooves.

According to the invention, the ridge forming a side wall of the gasket groove in each plate is provided, on the side of the ridge remote from this groove, with recesses so that the bottom of the adjacent furrow in the distribution surface acquires extensions in the direction toward the gasket groove. These recesses and corresponding extensions are aligned with the regions where the bottom of the aforementioned furrow is supported by the ridges of the adjacent plate, and the latter ridges are formed so that they extend sufficiently to engage these extensions of the bottom of the furrow.

For a better understanding of the invention, reference may be had to the accompanying drawings, in which:

FIG. I is a perspective view of two heat exchanging plates of the type described and which represent prior art;

FIG. 2 is a similar view of parts of these plates in more detail;

FIG. 3 is an enlarged sectional view on line III-III in FIG. 1;

FIG. 4 is a plan view of part of a plate made according to the invention;

FIG. 5 is an enlarged sectional view of parts of an assembly of three plates of the kind shown in FIG. 4, the sectional view being on the line VV in FIG. 4;

FIGS. 6 and 7 are views similar to FIG. 4 but showing other embodiments of the invention, and

FIG. 8 is an enlarged section view of parts of an assembly of three plates of the kind shown in FIG. 7, the sectional view being on the line VIIIVIII in FIG. 7.

Referring to FIG. 1, two paired plates'ofa plate heat exchanger of the type described are shown at A and B. The plates A and B each have four openings 1-4 and 11-14, respectively, and a gasket 5 and 15, respectively, situated in a groove extending along the periphery of the plate outside the said openings. The heat transferring portion of each plate is divided into three areas 6-8 and 16-18, respectively, of which the

central area

7 and 17, respectively, constitutes the main heat exchanging surface of the plate, where the most part of theheat transfer between the twomedia takes place. The plate A is intended to contact with'its rear side the front side of the plate B.

On the front side of the plate A, a heat exchanging medium is intended to flow from the opening 1 to the opening 3, while on the front side of the plate B (the rear side of the plate A) another heat exchanging medium is intended to flow from the opening 14 to the opening 12 (from the opening 4 to the opening 2) or in the reverse direction. On the front side of the plate A, the openings 2 and 4 are separated from the heat transferring portion of the plate by means of

gaskets

9 and 10, respectively; and on the front side of the plate B, the openings 11 and 13 are separated from the heat transferring portion of this plate by means of

gaskets

19 and 20, respectively.

In FIG. 2 there is shown a more detailed view of the distribution surfaces 6 and 16 of the plates A and B, respectively. The ditribution surface 6 of the plate is provided with parallel ridges 21, between which are formed furrows 22. Through these furrows, which are wider than the ridges, heat exchanging medium entering through the opening 1 is adapted to be distributed over the entire width of the main heat exchanging surface 7 of the plate. In the distribution surface 16 of the plate B, corresponding ridges 23 and furrows 24 are formed, which extend so that they form an angle with the ridges 21 and the furrows 22 of the plate A. Therefore, the ridges 23 of the plate B will cross and abut the ridges formed on the rear side of the plate A by the furrows 22.

At the ends of the ridges 21 situated nearest the opening 1, the plate A has a planar portion 25. This is adapted to be put into sealing abutment against the gasket 19 of the plate B when the plates A and B are put together. A similar planar portion 26 is provided on the plate B at the ends of the ridges 23 nearest the opening 12 and is adapted to seal against the gasket 9 of the next rear plate (not shown).

In FIG. 3 there is shown a cross-section along the line IIIIII in FIG. 1 through the plates A and B and a further plate C, the plate C being of the same kind as plate B. Shown in Cross-section are two of the ridges of the plate A, designated 21 and 21a, and a furrow 22' formed between these ridges. The ridge 21a forms a side wall of the previously mentioned groove in which the gasket 9 is situated, the bottom of this groove being designated 27. The plate B, situated below the plate A, is shown with one of the previously mentioned ridges 23, which cross and abut the underneath side of the furrow 22 of the plate A. The ridge 23 terminates at the previously mentioned planar portion 26 of the plate B. A corresponding planar portion 28 of the plate C abuts sealingly against the upper side of the gasket 9. A heat exchanging medium entering through the opening 1 of the plate A (FIG. 2) will flow through the furrows 22 in the interspace between the plates A and C (FIG. 3), i.e., perpendicular to the plane of the drawing in FIG. 3. Between the plates A and B, the other heat exchanging medium will flow parallel to the ridges 23 of the plate B, as indicated by arrows 29 in FIG. 3.

When a plate heat exchanger comprising plates of the described kind is put together, the plates are pressed against each other so that the gaskets are compressed and a sealing pressure is built up, heat exchange being possible with the heat exchanging media-at superatmospheric pressure. With this clamping together of the plates, the gasket extending along the periphery of each plate, corresponding to the gasket 5 or 15in FIG. 1, will seal against and simultaneously supportthe bottom of the groove of the adjacent plate, in which groove the corresponding gasket of the latter plate is situated. A corresponding support will not be obtained, however, for the bottoms of the grooves which receive the

plate gaskets

9 and 19. Thus, as can be seen from FIG. 3, the plate B situated below the groove bottom 27 has no gasket in this region, and this is necessary to enable flow of heat exchanging medium into this plate interspace (see arrows 29).

Due to the lack of support for the bottoms of these gasket grooves, the plates will deflect in these areas, if

they are pressed against each other with too large a force. This is illustrated by, a broken line 30 in H6. 3. The result will be that the

gaskets

9, and 19, in FIG. 1 will be compressed less than the other gaskets (i.e., the gaskets 5 and 15, respectively, around the periphery of the plates) and consequently will not be able to seal against as high a superatmospheric-pressure of the heat exchanging media as these other gaskets.

For solving this problem heretofore, the art has resorted to welding the plates of this kind, along the planar portions 25, 26and 28, supports such as undulated strips which, when the plates are pressed together, support the bottoms of the gasket grooves in the adjacent plates without substantially hindering the flow of a medium in the plate interspaces where the supports are situated. The use of such supports, however, complicates production of the heat exchanging plates. At the regions of the supports, there also may be formed pockets which are undesirable from the hygienic point of view.

Further, solid constituents in the heat exchanging medium, such as impurities, fibres, etc., may deposit on the supports and constitute obstacles to the medium flow.

The present invention provides an improved solution to the problem of non-support for certain portions of the plates in a plate heat exchanger of the abovedescribed kind.

The solution resides in the feature of forming each plate in the areas nearest the gasket grooves in a way such that the need of a special support of the abovementioned kind for the bottoms of these grooves is substantially decreased. The invention is characterized in that the ridge located in the distribution surface of each plate and forming the side wall of the gasket groove is provided, on its side remote from the gasket groove, with recesses so formed that the bottom of the distribution furrow nearest this ridge acquires extensions in the direction toward the gasket groove at the places where this furrow bottom'is supported by the ridges of the adjacent plate, which ridges are formed so that they extend up to andengage these extensions of the furrow bottom. By this configuration of the plates, they will support each other closer to the said gasket grooves than heretofore. Further, the ridge which forms the side wall of the gasket groove will acquire wall portions directed transversely to the gasket groove, which wall portions are situated in alignment with the support points created between the two inter-abutting plates in the areas in question. These two facts account for the plates being much more rigid in the direction transversely to the gasket groove and increase the strength of the plates at these very places where the plates support each other in this area. A deflection of the kind shown in FIG. 3 by broken line 30 may thus be substantially reduced for the heavy clamping pressures presently used.

In a preferred embodiment of the invention, the ridge forming the side wall of the gasket groove is both narrower and lower opposite to the places where the nearest furrow is extended. The wall portion of the ridge in question, which is directed transversely to the gasket groove, will thus be enlarged. Preferably, the lower portions of the ridge have the same extension in the longitudinal direction of the ridge as the extended portions of the said furrow. Between the extended portions of the furrow, the latter may have shallower portions with an extension such that the deep portions of the furrow are constituted only by grooves extending across the furrow in the bottom of the latter.

The plate A shown in FIG. 2 has parallel ridges 21 separated by furrows 22 which extend from the opening 1 to the central portion of the plate. The ridge situated nearest the gasket 9 forms a side wall of the groove for this gasket. This can be seen from FIG. 3 in which this ridge is designated 21a.

In previously known plates of this kind, the side face of the ridge 21a turned away from the gasket 9 is uninterrupted alongthe ridge. In a plate formed according to the invention, this is not the case, however. This can be seen from FIG. 4 which is a view of a part of such a plate and where the bottom of the groove for the gasket 9 is designated 27, as in FIG. 3. The ridge forming the side wall of the gasket groove, here designated 21b, merges in the bottom 27 of the gasket groove along a continuous line, whereby the ridge will give a continuous support to the gasket situated in the gasket groove along the whole length of it. The other side of the ridge 21b merges into a furrow in the ditribution surface of the plate, this furrow being designated 22a in FIG. 4. As can be seen from FIG. 4, the ridge 21b has several narrower portions 30 along its length. The furrow 22a at these places is thus extended in the direction toward the gasket groove, these extensions being designated 31 in FIG. 4.

In FIG. 4, broken lines indicate the extension of the ridges 23a of an adjacent plate, which ridges cross and abut the underneath side of the furrow 22a. These ridges designated 23a cross the furrow 22a at the very places where it is provided with extensions 31. The ridges 23a extend far enough to support the bottom of the furrow 22a and also the bottom of its extensions 31.

In FIG. 5, the cross-section through three plates formed according to the invention is taken along the line V-V in FIG. 4, i.e., through one of the narrow portions 30 of the ridge 21b and the corresponding extension 31 of the furrow 22a.

In FIG. 3, which shows plates formed according to prior art, a distance S is marked between the point where the'bottom 27 of the gasket groove merges into the ridge 21a and the point nearest the gasket groove where the furrow 22 situated on the other side of ridge 21a is supported on its underneath side by the ridges 23 of the adjacent plate. In FIG. 5 showing plates formed according to the invention, the corresponding distance is designated L. As can be seen, the distance L is substantially smaller than the distance S, which means that a plate formed according to the invention is better supported by the adjacent plate in the area of the gasket 9 than a plate formed according to prior art.

From FIGS. 4 and 5, it can also be seen that the ridge 21b is lower at its narrow portions 30 than at the other portions of its length. Owing to this particular shape of the ridge, parts of its walls will acquire an extension substantially across the longitudinal direction of the ridge. These parts of the ridge walls, designated 32, will make the plate rigid against deflection in the direction transversely to the ridge.

in FIG. 6 there is shown an alternative embodiment of the ridge 21b forming the side wall of the gasket groove. Each of the narrower portions 30a of the ridge 21b there shown has a length such that it extends past two of the crossing ridges 23a of the adjacent plate.

In FIG. 7 there is shown a plate at which the ridge 21b situated nearest the gasket groove has the same form as the ridge 21b in FIG. 4, while the furrow 22a extending beside the ridge has shallower portions 33 between the places where its bottom is supported by the ridges 23a of the adjacent plate.

As shown in FIG. 8, the surface 32 shown in FIG. 5 has acquired an extension 34 which extends across the whole width of the furrow 22a. Due to the surface formed by the

surfaces

32 and 34 together, a plate of this FIG. 8 embodiment will be especially rigid against deflection in the direction transversely to the gasket groove.

1 claim:

1. In the plate heat exchanger comprising paired plates each having a main heat exchanging portion, an inlet opening for a heat exchanging medium, and a distributing portion formed on one surface of the plate with furrows extending between said opening and main portion and with parallel ridges defining said furrows, the ridges and furrows on said one surface forming furrows and ridges, respectively, on the other surface of the plate, each said plate having outside its distributing portion a gasket groove partly defined by a side wall of an adjacent said ridge of the plate, said side wall merging into the bottom of the gasket groove along a continuous line, whereby a gasket situated in the groove will have a continuous support from said adjacent ridge, the ridges on one surface of one of said plates being arranged to cross and abut the ridges on the opposing surface of the other plate but extending short of supporting abutment with the bottom of the gasket groove of said other plate, the improvement wherein said adjacent ridge of each plate is provided, in its side wall remote from said gasket groove of the plate, with recesses forming extensions of the bottom of the adjacent furrow of the plate, said furrow extensions of each plate being in the direction toward the gasket groove of the plate, the furrow extensions of said other plate being aligned with regions where the bottom of said other plates said adjacent furrow is engaged and supported by the ridges of said one plate, said last ridges extending into abutment with said extensions of said other plate.

2. Paired plates according to claim 1, in which said adjacent furrow of each platehas relatively deep portions where said extensions of the furrow are located and has relatively shallow portions disposed between said deep portions.

3. Paired plates according to claim 2, in which said deep portions form grooves extending transversely of the furrow.

4. Paired plates according to claim 1, in which said adjacent ridge of each plate has relatively low portions opposite said extensions of the adjacent furrow.

5. Paired plates according to claim 4, in which each said low portion of the ridge has the same extension in the longitudinal direction of the ridge as the opposite said extension.

Claims

1. In the plate heat exchanger comprising paired plates each having a main heat exchanging portion, an inlet opening for a heat exchanging medium, and a distributing portion formed on one surface of the plate with furrows extending between said opening and main portion and with parallel ridges defining said furrows, the ridges and furrows on said one surface forming furrows and ridges, respectively, on the other surface of the plate, each said plate having outside its distributing portion a gasket groove partly defined by a side wall of an adjacent said ridge of the plate, said side wall merging into the bottom of the gasket groove along a continuous line, whereby a gasket situated in the groove will have a continuous support from said adjacent ridge, the ridges on one surface of one of said plates being arranged to cross and abut the ridges on the opposing surface of the other plate but extending short of supporting abutment with the bottom of the gasket groove of said other plate, the improvement wherein said adjacent ridge of each plate is provided, in its side wall remote from said gasket groove of the plate, with recesses forming extensions of the bottom of the adjacent furrow of the plate, said furrow extensions of each plate being in the direction toward the gasket groove of the plate, the furrow extensions of said other plate being aligned with regions where the bottom of said other plate''s said adjacent furrow is engaged and supported by the ridges of said one plate, said last ridges extending into abutment with said extensions of said other plate.

2. Paired plates according to claim 1, in which said adjacent furrow of each plate has relatively deep portions where said extensions of the furrow are located and has relatively shallow portions disposed between said deep portions.