Plate heat exchanger

Abstract

The invention relates to a plate heat exchanger ( 1 ) comprising at least one cassette ( 2 a - c ) formed by a pair of adjacent plates ( 3 a , b) in a plate stack ( 10 ). An inner heat transfer duct ( 4 ) runs between adjacent plates ( 3 a , b) within the cassette ( 2 a - c ). An insulating duct ( 6, 12 ) is disposed adjacent to the inner heat transfer duct ( 4 ) along at least one edge portion of the cassette ( 2 a - c ). The insulating duct ( 6, 12 ) is configured to insulate and separate the inside of the plate heat exchanger's heat transfer ducts ( 4, 11 ) from the environment outside the plate heat exchanger ( 1 ) in a direction transverse to a main heat transfer direction ( 7 ) through the plates ( 3 a, b ) of the cassette ( 2 a - c ) and thereby reduce temperature losses from the plate heat exchanger ( 1 ) to the surrounding environment.

1 . A plate heat exchanger ( 1 ) comprising at least one cassette ( 2   a - c ) formed by a pair of adjacent plates ( 3   a, b ), whereby an inner heat transfer duct ( 4 ) and, adjacent thereto along at least an edge portion ( 5 ,  13 ,  16 ,  17 ) of the cassette ( 2   a - c ), an insulating duct ( 6 ,  12 ,  14 ,  15 ) run between the plates ( 3   a, b ) within the cassette ( 2   a - c ), whereby insulating ducts ( 6 ,  12 ,  14 ,  15 ) are configured to separate the inner heat transfer duct ( 4 ) from the environment outside the plate heat exchanger ( 1 ) in a direction transverse to a main heat transfer direction ( 7 ) through the plates ( 3   a, b ) of the cassette ( 2   a - c ). 
     
     
         2 . A plate heat exchanger ( 1 ) according to  claim 1 , in which the respective plates ( 3   a, b ) each comprise an inner side ( 8 ) and an outer side ( 9 ), which plates ( 3   a, b ) are laid on one another in a plate stack ( 10 ), every alternate plate ( 3   a, b ) in the plate stack ( 10 ) being inverted, whereby the inner sides ( 8 ) of two adjacent plates ( 3   a, b ) face towards one another, forming said cassette ( 2   a - c ), and/or the outer sides ( 9 ) of two adjacent plates ( 3   a, b ) face towards one another, forming between them an outer heat transfer duct ( 11 ). 
     
     
         3 . A plate heat exchanger ( 1 ) according to  claim 2 , in which insulating ducts ( 6 ,  12 ,  14 ,  15 ) are configured transversely to the heat transfer direction ( 7 ) to separate the outer heat transfer duct ( 11 ) from the environment outside the plate heat exchanger ( 1 ). 
     
     
         4 . A plate heat exchanger ( 1 ) according to  claim 2 , in which the plates ( 3   a, b ) in the plate stack ( 10 ) form adjacent cassettes ( 2   a - c ), whereby the outer heat transfer duct ( 11 ) runs between the cassettes ( 2   a - c ). 
     
     
         5 . A plate heat exchanger ( 1 ) according to  claim 1 , in which a second insulating duct ( 12 ) is disposed along a second edge portion ( 13 ) opposite to the first edge portion ( 5 ), whereby the inner heat transfer duct ( 4 ) is disposed between the first and second edge portions ( 5 ,  13 ). 
     
     
         6 . A plate heat exchanger ( 1 ) according to  claim 1 , in which a third and an opposite fourth insulating duct ( 14 ,  15 ) are disposed along a third and an opposite fourth edge portion ( 16 ,  17 ) of the cassette ( 2   a - c ) along the periphery of the cassette ( 2   a - c ), and said insulating ducts ( 6 ,  12 ,  14 ,  15 ) are so disposed that they together surround the inner heat transfer duct ( 4 ) and form an insulating duct ( 6 ,  12 ,  14 ,  15 ) which extends round said periphery. 
     
     
         7 . A plate heat exchanger ( 1 ) according to  claim 1 , in which each said plate ( 3   a, b ) forming a cassette ( 2   a - c ) comprises: said edge portions ( 5 ,  13 ,  16 ,  17 ); port recesses ( 18 ); the plate inner side ( 8 ) with the inner heat transfer surface ( 19 ) with an inner pattern ( 20 ); the plate outer side ( 9 ) with an outer heat transfer surface ( 21 ) with an outer pattern ( 22 ); whereby the inner pattern ( 20 ) of the plate ( 3   a, b ) is disposed between a neutral plane ( 23 ) which runs in the plate ( 3   a, b ) perpendicular to the heat transfer direction ( 7 ) through the plate ( 3   a, b ) and an inner plane ( 24 ) which runs parallel in the neutral plane ( 23 ) of the plate ( 3   a, b ); the outer pattern ( 22 ) of the plate ( 3   a, b ) is disposed between the neutral plane ( 23 ) and an outer plane ( 25 ) which runs parallel in the plate ( 3   a, b ); and the height of the inner pattern ( 20 ) between the inner plane ( 24 ) and the neutral plane ( 23 ) is less than the height of the outer pattern ( 22 ) between the neutral plane ( 23 ) and the outer plane ( 25 ). 
     
     
         8 . A plate heat exchanger ( 1 ) according to  claim 1 , in which an outer sealing surface ( 26 ) is arranged in the outer plane ( 25 ) in each plate ( 3   a, b ) of the cassette ( 2   a - c ) along the edge portions ( 5 ,  13 ,  16 ,  17 ) of the respective outer sides ( 9 ) of the plates ( 3   a, b ) of the cassette ( 2   a - c ) on the opposite side from the region of the insulating ducts ( 6 ,  12 ,  14 ,  15 ). 
     
     
         9 . A plate heat exchanger ( 1 ) according to  claim 1 , in which an inner sealing surface ( 27 ) is disposed in the inner plane ( 24 ) in each plate ( 3   a, b ) of the cassette ( 2   a - c ) along the edge portions ( 5 ,  13 ,  16 ,  17 ) on the cassette ( 2   a - c ) between the adjacent plate side ( 8 ) of the respective plate ( 3   a, b ) transversely to the heat transfer direction ( 7 ) outside the insulating ducts ( 6 ,  12 ,  14 ,  15 ). 
     
     
         10 . A plate heat exchanger ( 1 ) according to  claim 9 , in which the inner sealing surface ( 27 ) in each plate ( 3   a, b ) disposed transversely to the heat transfer direction ( 7 ) is outside the outer sealing surface ( 26 ) on the edge portion ( 5 ,  13 ,  16 ,  17 ) of the respective plate ( 3   a, b ). 
     
     
         11 . A plate heat exchanger ( 1 ) according to  claim 9 , in which the respective plates ( 3   a, b ) in a pair of plates forming a cassette ( 2   a - c ) are connected to one another via the inner sealing surface ( 27 ) of the respective adjacent plate ( 3   a, b ). 
     
     
         12 . A plate heat exchanger ( 1 ) according to  claim 9 , in which two adjacent cassettes ( 2   a - c ) are connected to one another via the outer sealing surface ( 26 ) of the respective plate ( 3   a, b ), whereby the outer heat transfer duct ( 11 ) runs between the cassettes ( 2   a - c ) and is delineated between the outer sealing surfaces ( 26 ). 
     
     
         13 . A plate heat exchanger ( 1 ) according to  claim 2 , in which the inner heat transfer duct ( 4 ) is adjacent to the outer heat transfer duct ( 11 ), and the respective insulating ducts ( 6 ,  12 ,  14 ,  15 ) are adjacent to one another. 
     
     
         14 . A plate heat exchanger ( 1 ) according to  claim 2 , in which an end plate ( 28   a, b ) is disposed against the outermost plate ( 3   a, b ) of the plate stack ( 10 ), whereby an end duct ( 29   a, b ) runs between the plate ( 3   a, b ) and the end plate ( 28   a, b ), the end duct ( 29   a, b ) communicates with at least one insulating duct ( 6 ,  12 ,  14 ,  15 ) in the plate heat exchanger ( 1 ), and the end duct ( 29   a, b ) is configured to insulatingly separate the inside ( 30 ) of the plate heat exchanger ( 1 ) from the environment outside the plate heat exchanger ( 1 ) in the heat transfer direction ( 7 ) of the plate heat exchanger ( 1 ). 
     
     
         15 . A plate heat exchanger ( 1 ) according to  claim 1 , in which adjacent plates ( 3   a, b ) in the plate heat exchanger ( 1 ) are permanently connected to one another.