(19)
(11)EP 2 326 901 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
26.06.2019 Bulletin 2019/26

(21)Application number: 09788599.0

(22)Date of filing:  24.08.2009
(51)International Patent Classification (IPC): 
F28D 9/00(2006.01)
F28F 3/08(2006.01)
(86)International application number:
PCT/SE2009/050946
(87)International publication number:
WO 2010/036183 (01.04.2010 Gazette  2010/13)

(54)

A PLATE HEAT EXCHANGER

PLATTENWÄRMENTAUSCHER

ÉCHANGEUR DE CHALEUR A PLAQUES


(84)Designated Contracting States:
AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO SE SI SK SM TR

(30)Priority: 23.09.2008 SE 0850020

(43)Date of publication of application:
01.06.2011 Bulletin 2011/22

(73)Proprietor: Alfa Laval Corporate AB
221 00 Lund (SE)

(72)Inventors:
  • JOENSEN, Hjalmar
    DK-6705 Esbjerg (DK)
  • PAULSSON, Göran
    S-212 30 Malmö (SE)

(74)Representative: Alfa Laval Attorneys 
Alfa Laval Corporate AB Patent Department P.O. Box 73
221 00 Lund
221 00 Lund (SE)


(56)References cited: : 
WO-A1-01/90671
WO-A1-97/39301
WO-A1-2006/104443
GB-A- 1 240 039
US-A- 4 291 752
WO-A1-97/23759
WO-A1-2006/043864
WO-A2-99/66279
US-A- 2 379 671
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    AREA OF INVENTION



    [0001] The present invention refers generally to plate heat exchangers allowing a heat transfer between two fluids at different temperature for various purposes. Specifically, the invention relates to a plate heat exchanger being configured so that the ports of the heat exchanger plates are gathered in a centre portion of the heat exchanger plate and having a end plate adapted to the location of the ports.

    BACKGROUND OF INVENTION



    [0002] The present invention refers generally to a plate heat exchanger for distillation of a medium, e.g. desalination of salt-containing water, such as seawater. For treatment of a medium the plate heat exchanger comprises a number of compression-molded heat exchanger plates, which are successively provided in a plate package and which form first plate interspaces for the medium and second plate interspaces, wherein the first plate interspaces and the second plate interspaces are provided in an alternating order in the plate package.

    [0003] Traditionally the plate heat exchanger or desalination apparatus comprise several separate plate heat exchangers since the all steps of desalination could not be performed in a single standard plate heat exchanger. To simplify the equipment or apparatus for desalination of seawater a new kind of plate heat exchanger has been developed, which described in EP-A1-1 864 069. It discloses a plate heat exchanger comprising the features of the preamble of claim 1, the plate heat exchanger being configured as a desalination plant comprising a plate package, where the several ports of the heat exchanger plates are located in centre portion of the heat exchanger plates. In traditional plate heat exchangers the ports are located in the corners of the heat exchanger plate, close to the tie bolts which takes up the stress. In EP-A1-1 864 069 having the ports are located a centre portion, whereby another distribution of the mechanical stress, the end plate need to be configured differently to take the stress. Further having several of the main ports of the heat exchanger plate in a rather limit space of the heat exchanger plate and thereby also the corresponding port outlets on the end plate in a limit space of the end plate makes the location of the connections coupled to the port outlets rather tight with the standard solution of the connections as shown in EP-A1-1 864 069.

    DISCLOSURE OF INVENTION



    [0004] The object of the invention is to provide an improved plate heat exchanger having an end plate, which is adapted for a heat exchanger plate having the ports located in a centre portion of the heat exchanger plate.

    [0005] This object is achieved by the plate heat exchanger as defined in claim 1.

    [0006] According to an embodiment of the invention the centre axis extends substantially centrally between two side edges of each of the heat exchanger plates and substantially vertically when the plate package is disposed in a normal position of use, and the inlets and outlets of the heat exchanger plates are located along the centre axis.

    [0007] According to a further embodiment of the invention the connecting part projects equilaterally along the vertical axis of said at least one end plate to form a substantial triangular shape having a base towards said at least one end plate and two sides projecting from said base. At least one of the connections is arranged on each of the sides of the connecting part that are directed away from the end plate of the plate heat exchanger.

    [0008] According to a further embodiment of the invention the connecting part is arranged as a reinforcement part of said at least one end plate to withstand the stress that said at least one end plate is exposed to during operation. The connecting part can be an integrated part of said at least one end plate or it can be mounted separately onto said at least one end plate by any suitable fastening means.

    [0009] According to a further embodiment of the invention said at least one end plate can be provided with reinforcement portions in stress-exposed parts, where the reinforcement portions are provided as added thickness of said at least one end plate, i.e. the thickness of said at least one end plate vary depending on the stress so that areas exposed to more stress are thicker and other areas are thinner.

    [0010] Further aspects of the invention are defined in the dependent claims.

    BRIEF DESCRIPTION OF THE DRAWINGS



    [0011] Embodiments of the invention are now to be explained more closely by means of a description of various embodiments and with reference to the drawings attached hereto.

    Figs. 1-2 disclose perspective views of a plate heat exchanger according to an embodiment of the invention;

    Fig. 3 discloses a front view of a first end plate in a plate heat exchanger according to an embodiment of the invention;

    Fig. 4 discloses a side view of a plate heat exchanger according to an embodiment of the invention;

    Fig. 5 discloses a perspective view of a plate heat exchanger according to an embodiment of the invention, where the plate heat exchanger is open;

    Fig. 6 discloses a front view perspective view of a heat exchanger plate used in a plate heat exchanger according to an embodiment of the invention;

    Fig. 7 discloses a front view of a second end plate in a plate heat exchanger according to an embodiment of the invention as seen from the line A-A of Fig. 4;

    Figs. 8-9 are cross sectional views of a carrying bar of a plate heat exchanger according to an embodiment of the invention and partial detailed views of the second end plate and a hanging arrangement as seen from the line A-A of Fig. 4; and

    Fig. 10 is partial detailed side of the carrying bar of the plate heat exchanger according to an embodiment of the invention and the second end plate.


    DETAILED DESCRIPTION OF EMBODIMENTS



    [0012] Heat exchangers are used for transferring heat between two fluids separated by a solid body. Heat exchangers can be of several types, the most common are spiral heat exchangers, tubular heat exchangers and plate heat exchangers. Plate heat exchangers are used for transferring heat between a hot and a cold fluid that are flowing in alternate flow passages formed between a set of heat exchanger plates. The arrangement of heat exchanger plates defined above is enclosed between end plates that are relatively thicker than the heat exchanger plates. The inner surface of each end plate faces the heat transfer plates.

    [0013] Figs. 1-2 disclose a plate heat exchanger 100 for treatment of a medium, typically used for an application with respect to desalination of seawater, i.e. a fresh water generator. The plate heat exchanger 100 comprises a large number of compression-molded heat exchanger plates 1, which are provided in parallel to each other and successively in such a way that they form a plate package 2. The plate package 2 is provided between a first end plate 3, also called frame plate, and a second end plate 4, also called pressure plate. Between the heat exchanger plates 1, first plate interspaces and second plate interspaces are formed.

    [0014] The first plate interspaces and the second plate interspaces are provided in an alternating order in the plate package 2 in such a way that substantially each first plate interspace is surrounded by two second plate interspaces, and substantially each second plate interspace is surrounded by two first plate interspaces. Different sections in the plate package 2 are delimited from each other by means of gaskets in each plate interspace. The gasket, which is preferably made of an elastic material, e.g. rubber material, is disposed in a groove which extends along the periphery of the constituent heat exchanger plates 1 and around ports. The gasket may possibly comprise a metal or be surrounded by a second material, e.g. metal, PTFE, etc.

    [0015] As shown in Fig. 6 each heat exchanger plate 1 has two opposite substantially parallel side edges 7, 8, an upper edge 9 and a lower edge 10. A centre axis X extends substantially centrally between the two side edges 7 and 8, and substantially vertically when the plate package 2 is located in a normal position of use.

    [0016] As shown in Fig. 1, the plate package 2, i.e. the heat exchanger plates 1 and the gaskets (not shown) provided there between, is kept together between the end plates 3 and 4 by means of threaded tie bolts 11 in a manner known per se. The tie bolts 11 extends from the first end plate 3 and passing through holes or recesses in the edge portions of the second end plate 4. Each tie bolt 11 has a bolt head means at one of its ends, possibly situated at the outside (or integrated in) of the first end plate 3, and carries nuts on its threaded part, possibly situated at the outside (or integrated in) of the end plate 4.

    [0017] The heat exchanger plates 1 are arranged hanging on two carrying bolts 5, 6 that substantially extend between the first end plate 3 and a support column 12. The heat exchanger plate 1 is provided with cut-in portions 15 (see Fig. 6) provided on each of the side edges 7 and 8. The first end plate 3 is connected to the support column 12 by a carrying bar 13, which in one end is fixedly attached to an upper end of the first end plate 3 and in the opposite end fixedly attached to an upper end of the support column 12. The second end plate 4, which is movable along the carrying bar 13, is used to press the heat exchanger plates 1 together to form the plate package 2. A guide bar 14, that guides the heat exchanger plates 1 in their lower end, connects a lower portion of the support column 12 with a lower part of the first end plate 3.

    [0018] The heat exchanger plate 1 discussed above includes in a manner known per se a corrugation or pattern for increasing the heat transfer and a number of port holes for forming a corresponding number of port channels extending through the plate package and being in connection with the flow channels formed between the heat exchanger plates 1.

    [0019] The end plate 3 is suitably provided with a number of port outlets or connections 27, 33, 19, 20, 44, 45, 55 and 56 corresponding to ports 25, 33, 17, 18, 42, 43 and 50 of the heat exchanger plate 1. Due to the specific duties of the plate heat exchanger 100, the plate package 2 encloses an evaporation section E, a separation section S and a condensation section C (see Fig. 9). The evaporation section E is arranged to permit evaporation of at least a part of the medium flowing through the first plate interspaces. The separation section S is arranged to separate non-evaporated liquid from the evaporated part of the medium. The condensation section C is arranged to condense the evaporated part flowing through the first plate interspaces. The centre axis X extends substantially centrally through the evaporation section E, the separation section S and the condensation section C. As can be seen in Fig. 9, the evaporation section E is located at a lowermost position, the condensation section C at an uppermost position and the separation section S between the evaporation section E and the condensation section C, when the plate heat exchanger 100 is in the normal position of use.

    [0020] The several functions, i.e. evaporation, condensation and separation, of the plate heat exchanger 100 necessitate more connections on the end plate or frame 3 than in a traditional plate heat exchanger. Especially the ports 17, 18, 42, 43 and 50 along the centre axis X, which is a rather limit space on the end plate 3, demands an innovative solution. For that reason the centre portion, extending the lower end to the upper end, of the end plate 3 is formed with a connecting or projecting part 60. The connecting part 60 of the end plate 3, which extends equilaterally or from a main surface of the end plate 3, is a substantially regular triangle or isosceles triangle shaped with the base towards the end plate 3. On the sides or flanks of the triangular shaped connecting part 60 are arranged with connections 19-20 and 44-45, which can be arranged relatively narrow, since they are arranged alternately on the two sides of the substantial triangle 60. Thereby standard connections can be used even though that a relatively short or compact heat exchanger plate 1 is used. This would not be possible a flat end plate 3 had used since the space would not be enough for the standard connections when having five connections, could be more also, arranged along a vertical axis in the centre of the end plate and when having a relatively short heat exchanger plate 1. The end plate 3 is further provided yet another number of connections, e.g. another two connections 55, 56 on the projecting part 60 and connections 27, 33 on other part of the end plate 3. Each of the connections of the end plate 3 is connected to a corresponding port on the heat exchanger plate 1.

    [0021] The end plate 3 is further tailor-made to include reinforcement on those portions of the end plate 3, which are exposed to additional or increased stress. This is accomplished by adding material or adding thickness to the end plate 3 only on those parts of the end plate 3 being exposed to stress, e.g. the mounting locations of the tie bolts 11 and the connections. By tailor-made the design of the end plate 3 to withstand the different stress in the different parts of the end plate 3, instead of over-dimensioning the entire end plate 3, substantial savings can be made in reduced need of material, thus also costs.

    [0022] To achieve a first end plate 3 having varied thickness and a projecting connecting 60 the end plate 3 is preferably made by casting, molding, founding or any other similar and suitable manufacturing process.

    [0023] In Fig. 7 is shown the second end plate 4 and a cross-section of the carrying bar 13. The end plate 4 is arranged hanging on the carrying bar 13. In prior art plate heat exchangers, both the heat exchanger plates and the moveable end plate are arranged hanging on a T-profile arranged on the underside of the carrying bar. As the heat exchanger plates 1 in the present invention are arranged hanging on carrying bolts 5, 6 the need for T-profile arranged along the entire underside of the carrying bar is small, but only an arrangement 30 for hanging the second end plate 4 is needed. In Fig. 7 this arrangement 30 is formed as short profile, e.g. IPF profile, which movably connects the end plate 4 with the carrying bar 13. The length of the hanging profile 30 along the longitudinal direction of the carrying bar 13 corresponds to the thickness of the end plate 4.

    [0024] In Figs.8 and 9 a partial, detailed cross-section of the hanging profile 30, the carrying bar 13 and the end plate 4 is shown. The one portion of the hanging profile 30 is received in cut-out portion 31 in an upper end of the second end plate 4, and can be attached to the second end plate 4 by using various attachment means known in the art, e.g., screws, bolts, welding, etc. The shape of the cut-out portion 31 corresponds to a lower portion 32 of the hanging profile 30, and is substantially formed as a T turned upside down. Similarly another portion of the hanging profile 30 is movably received in cut-out portion 36 in the lower part of the carrying bar 13. The shape of the cut-out portion 36 of the carrying bar 13 corresponds to an upper portion 34 of the hanging profile 30, and is substantially formed as a T. The upper portion 34 of the hanging profile 30 is provided with plastic bearings 35 on each of the "legs" of the T-shape so that the hanging profile 30 can slide on the bearings 35 when it is received in the cut-out portion 36 of the carrying bar 13. The corresponding surface of the cut-out portion of the carrying bar 13 upon which the plastic bearings 35 slide is preferably made of a low friction material, such as an anodized aluminum profile.

    [0025] In Fig. 10 a partial detailed cross-section along the longitudinal direction of the carrying bar 13 is shown. From Fig. 10 it is clear that the plastic bearings 35 have substantially the same length as the hanging profile 30. The cut-out portion 36 extends along substantially the entire length of the carrying bar 13, and in Fig. 10 a part of the channel formed by the cut-out portion 36 in the lower part of the carrying bar 13 and in which the hanging profile 30 run or slides is shown. From the outside the cut-out portion 36 appears as a slits on underside of the carrying bar 13. The support column 12 and the carrying bar 13 have identical cross-sections and in Figs. 1, 2 and 5 a slits 36 is shown on the support column 12, which corresponds to the slits/ cut-out portion 36 of the carrying bar 13.

    [0026] The invention is not limited to the embodiments described above and shown on the drawings, but can be supplemented and modified in any manner within the scope of the invention as defined by the enclosed claims.


    Claims

    1. A plate heat exchanger (100) for treatment of a medium, comprising a number of compression-molded heat exchanger plates (1), which are successively provided in a plate package (2) and which form first plate interspaces and second plate interspaces, wherein the first plate interspaces and the second plate interspaces are provided in an alternating order in the plate package (2), where the inlet and outlets (17, 18, 42, 43, 50) of the heat exchanger plate (1) are located in a centre portion of the plate heat exchanger, and where the plate package (2) is arranged between end plates on each side of the plate package (2), wherein at least one of the end plates are provided with connections in the centre portion of the at least one end plate and the location of the connections on the at least one end plate correspond to the location of the inlet and outlets of the heat exchanger plate (1), wherein at least one connection (19, 20, 44, 45, 55) of the end plate (3) is arranged in a connecting part (60) on the end plate, where the connecting part (60) extends along a vertical axis of the end plate corresponding to the centre axis (X) of heat exchanger plate (1), characterized in that the connecting part (60) projects from the end plate (3) in a direction away from the plate package (2) and the connecting part (60) is arranged as a reinforcement part of the end plate (3).
     
    2. A plate heat exchanger according to claim 1, wherein a centre axis (X) extends substantially centrally between two side edges (7, 8) of each heat exchanger plate (1) and substantially vertically when the plate package (2) is disposed in a normal position of use, and that the ports (17, 18, 42, 43, 50) of the heat exchanger plate (1) are located along the centre axis (X).
     
    3. A plate heat exchanger according to any of the preceding claims, wherein the connecting part (60) projects equilaterally along its longitudinal extension to form a substantial triangular shape having the base towards the end plate (3).
     
    4. A plate heat exchanger according to claim 3, wherein at least one connection (19, 20, 44, 45) is arranged on each of the sides of the connecting part (60).
     
    5. A plate heat exchanger according to any of the preceding claims, wherein the connecting part (60) is an integrated part of the end plate (3).
     
    6. A plate heat exchanger according to any preceding claim, wherein the end plate (3) is provided with reinforcement portions in stress-exposed parts, where the reinforcement portions are provided as added thickness of the end plate (3).
     


    Ansprüche

    1. Plattenwärmetauscher (100) zur Behandlung eines Mediums, der eine Anzahl von formgepressten Wärmetauscherplatten (1) umfasst, die aufeinanderfolgend in einem Plattenpaket (2) bereitgestellt werden und die erste Plattenzwischenräume und zweite Plattenzwischenräume bilden, wobei die ersten Plattenzwischenräume und die zweiten Plattenzwischenräume in einer abwechselnden Reihenfolge in dem Plattenpaket (2) bereitgestellt werden, wobei der Einlass und die Auslässe (17, 18, 42, 43, 50) der Wärmetauscherplatte (1) in einem Mittelabschnitt des Plattenwärmetauschers angeordnet sind und wobei das Plattenpaket (2) zwischen Endplatten auf jeder Seite des Plattenpakets (2) angeordnet ist, wobei wenigstens eine der Endplatten mit Verbindungen in dem Mittelabschnitt der wenigstens einen Endplatte versehen ist und die Position der Verbindungen an der wenigstens einen Endplatte der Position des Einlasses und der Auslässe der Wärmetauscherplatte (1) entspricht, wobei wenigstens eine Verbindung (19, 20, 44, 45, 55) der Endplatte (3) in einem verbindenden Teil (60) an der Endplatte angeordnet ist, wo sich der verbindende Teil (60) entlang einer vertikalen Achse der Endplatte erstreckt, die der Mittelachse (X) der Wärmetauscherplatte (1) entspricht, dadurch gekennzeichnet, dass der verbindende Teil (60) von der Endplatte (3) in einer Richtung, von dem Plattenpaket (2) weg, vorspringt und der verbindende Teil (60) als ein Verstärkungsteil der Endplatte (3) angeordnet ist.
     
    2. Plattenwärmetauscher nach Anspruch 1, wobei sich eine Mittelachse (X) im Wesentlichen zentral zwischen zwei Seitenkanten (7, 8) jeder Wärmetauscherplatte (1) und im Wesentlichen in Vertikalrichtung erstreckt, wenn das Plattenpaket (2) in einer normalen Verwendungsposition angeordnet ist, und die Anschlüsse (17, 18, 42, 43, 50) der Wärmetauscherplatte (1) entlang der Mittelachse (X) angeordnet sind.
     
    3. Plattenwärmetauscher nach einem der vorhergehenden Ansprüche, wobei der verbindende Teil (60) gleichseitig entlang seiner Längsausdehnung vorspringt, um eine im Wesentlichen dreieckige Form zu bilden, welche die Basis zu der Endplatte (3) hin aufweist.
     
    4. Plattenwärmetauscher nach Anspruch 3, wobei wenigstens eine Verbindung (19, 20, 44, 45) auf jeder der Seiten des verbindenden Teils (60) angeordnet ist.
     
    5. Plattenwärmetauscher nach einem der vorhergehenden Ansprüche, wobei der verbindende Teil ein integrierter Teil (60) der Endplatte (3) ist.
     
    6. Plattenwärmetauscher nach einem der vorhergehenden Ansprüche, wobei die Endplatte (3) mit Verstärkungsabschnitten in Beanspruchung ausgesetzten Teilen versehen ist, wo die Verstärkungsabschnitte als zusätzliche Dicke der Endplatte (3) bereitgestellt werden.
     


    Revendications

    1. Echangeur de chaleur à plaques (100) pour le traitement d'un milieu, comprenant plusieurs plaques d'échangeur de chaleur moulées par compression (1) agencés successivement dans un ensemble de plaques (2) et formant des premiers espaces intercalaires entre les plaques et des deuxièmes espaces intercalaires entre les plaques, dans lequel les premiers espaces intercalaires entre les plaques et les deuxièmes espaces intercalaires entre les plaques sont agencés dans un ordre alterné dans l'ensemble de plaques (2), l'entrée et les sorties (17, 18, 42, 43, 50) des plaques d'échangeur de chaleur (1) étant agencées dans une partie centrale de l'échangeur de chaleur à plaques, et dans lequel l'ensemble de plaques (2) est agencé entre des plaques d'extrémité de chaque côté de l'ensemble de plaques (2), au moins une des plaques d'extrémité étant pourvue de connexions dans la partie centrale de la au moins une plaque d'extrémité, l'emplacement des connexions sur la au moins une plaque d'extrémité correspondant à l'emplacement de l'entrée et des sorties de la plaque d'échangeur de chaleur (1), dans lequel au moins une connexion (19, 20, 44, 45, 55) de la plaque d'extrémité (3) est agencée dans une partie de connexion (60) sur la plaque d'extrémité, la partie de connexion (60) s'étendant le long d'un axe vertical de la plaque d'extrémité correspondant à l'axe central (X) de la plaque d'échangeur de chaleur (1), caractérisé en ce que la partie de connexion (60) déborde de la plaque d'extrémité (3) dans une direction allant à l'écart de l'ensemble de plaques (2), la partie de connexion (60) étant agencée comme une partie de renforcement de la plaque d'extrémité (3).
     
    2. Echangeur de chaleur à plaques selon la revendication 1, dans lequel un axe central (X) s'étend de manière sensiblement centrale entre deux bords latéraux (7, 8) de chaque plaque d'échangeur de chaleur (1), et de manière sensiblement verticale lorsque l'ensemble de plaques (2) est disposé dans une position d'utilisation normale, des orifices (17, 18, 42, 43, 50) de la plaque d'échangeur de chaleur (1) étant agencés le long de l'axe central (X).
     
    3. Echangeur de chaleur à plaques selon l'une quelconque des revendications précédentes, dans lequel la plaque de connexion (60) déborde de manière équilatérale le long de son extension longitudinale pour établir une forme sensiblement triangulaire dont la base s'étend vers la plaque d'extrémité (3).
     
    4. Echangeur de chaleur à plaques selon la revendication 3, dans lequel au moins une connexion (19, 20, 44, 45) est agencée sur chacun des côtés de la partie de connexion (60).
     
    5. Echangeur de chaleur à plaques selon l'une quelconque des revendications précédentes, dans lequel la partie de connexion (60) est une partie intégrée de la plaque d'extrémité (3).
     
    6. Echangeur de chaleur à plaques selon l'une quelconque des revendications précédentes, dans lequel la plaque d'extrémité (3) est pourvue de parties de renforcement dans des parties exposées à une contrainte, les parties de renforcement conférant une épaisseur additionnelle à la plaque d'extrémité (3).
     




    Drawing


























    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description