Heat exchanger of crossflow type

Abstract

The invention relates to a heat exchanger ( 1 ) of crossflow type for heat exchange between different media, which heat exchanger ( 1 ) comprises a plate stack ( 2 ) of heat transfer plates for first and second plate types ( 3, 4 ). The plate types ( 3,4 ) are stacked 5 alternately on one another in the plate stack ( 2 ). Each plate type ( 3, 4 ) has a side A and a side B with a heat exchange surface ( 9 ). The heat exchange surface ( 9 ) comprises a pattern ( 10 a, b ). In the plate stack ( 2 ), adjacent plate types ( 3, 4 ) form both first throughflow ducts ( 14 ) and second throughflow ducts ( 15 ). Said first throughflow ducts ( 14 ) have a larger volume than said second throughflow ducts ( 15 ), the volume of a first medium ( 16 ) in said 10 first throughflow ducts ( 14 ) being greater than the volume of a second medium ( 17 ) in said second throughflow ducts ( 15 ). Said media ( 16, 17 ) are subject to heat transfer between them through the heat exchange surface ( 9 ) between the ducts ( 14, 15 ), the pressure drop of medium ( 16 ) flowing through the first throughflow duct ( 14 ) being less than the pressure drop of medium ( 17 ) flowing through the second throughflow duct ( 15 ).

1 . A heat exchanger ( 1 ) of crossflow type for heat exchange between different media, comprising a plate stack ( 2 ) which itself comprises a number of heat transfer plates of a first plate type ( 3 ) and of a second plate type ( 4 ), which plate types ( 3 ,  4 ) are stacked alternately on one another in the plate stack ( 2 ) and each have two opposite long sides ( 5   a, b ), two opposite short sides ( 6   a, b ), first and second portholes ( 7 ,  8 ) disposed close to a short side ( 6   a ), a side A which has a heat exchange surface ( 9 ), a side B comprising the other side of said heat exchange surface ( 9 ), which heat exchange surface ( 9 ) has a pattern ( 10   a, b ) comprising a portion with dimples ( 11 ) and is disposed between the long and short sides ( 5   a, b ,  6   a, b ), which heat exchange surface ( 9 ) of each plate type ( 3 ,  4 ) is disposed between first and second planes ( 12 ,  13 ), whereby side A of a first plate type ( 3 ) is connected and adjacent to side B of a second plate type ( 4 ) in a first plane ( 12 ) between adjacent plate types ( 3 ,  4 ) forming a first throughflow duct ( 14 ), and side B of a first plate type ( 3 ) is connected to side A of a second plate type ( 4 ) in a second plane ( 13 ) between adjacent plate types ( 3 ,  4 ) forming a second throughflow duct ( 15 ), characterised in that said first throughflow duct ( 14 ) has a larger volume than said second throughflow duct ( 15 ), whereby the volume of a first medium ( 16 ) in said first throughflow duct ( 14 ) is greater than the volume of the second medium ( 17 ) in said second throughflow duct ( 15 ), which said media ( 16 ,  17 ) are subject to heat transfer between them through the heat exchange surface ( 9 ) between the ducts ( 14 ,  15 ), the pressure drop of the medium ( 16 ) flowing through the first throughflow duct ( 14 ) being smaller than the pressure drop of the medium ( 17 ) flowing through the second throughflow duct ( 15 ). 
   
   
       2 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that round each porthole ( 7 ,  8 ) in the first plate type ( 3 ) a first edge region ( 18 ) is disposed in the first plane ( 12 ) and constitutes an abutment surface against a second edge region ( 19 ) disposed round each porthole ( 7 ,  8 ) of the second plate type ( 4 ), which second plate type ( 4 ) is disposed on the first plate type ( 3 ) in the plate stack ( 2 ), whereby side A of the first plate type ( 3 ) is connected and adjacent to side B of the second plate type ( 4 ). 
   
   
       3 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that a divider ( 20 ), preferably stamped, is disposed in the heat exchange surface ( 9 ) of one plate type ( 3 ,  4 ), preferably the first plate type, and extends from the short side ( 6   a ) where said portholes ( 7 ,  8 ) are situated towards the second short side ( 6   b ), which divider ( 20 ) is shorter than said long sides ( 5   a, b ), is disposed between them and is disposed parallel between said long sides ( 5   a, b ). 
   
   
       4 . A heat exchanger ( 1 ) according to  claim 3 , characterised in that the divider ( 20 ) of the first plate type ( 3 ) comprises a ridge ( 21 ) or bottom ( 21 ) situated in the second plane ( 13 ) on side B of the first plate type ( 3 ), whereby the divider ( 20 ) is connected to side A of an adjacent second plate type ( 4 ), thereby forming between two plate types ( 3 ,  4 ) a passage between a free end ( 22 ) of the divider ( 20 ) and a short side ( 6   b ) of the plate types ( 3 ,  4 ). 
   
   
       5 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that the first throughflow duct ( 14 ) is disposed between respective long sides ( 5   a, b ) and between two adjacent plate types ( 3 ,  4 ) which are connected to one another in said first plane ( 12 ). 
   
   
       6 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that the second throughflow duct ( 15 ) is disposed in the second plane ( 13 ) and extends between said ports ( 7 ,  8 ), whereby said second throughflow duct ( 15 ) extends from the first short side ( 6   a ) situated adjacent to the first porthole ( 7 ) towards the second short side ( 6   b ) between the divider ( 20 ) and one long side ( 5   a ), through the passage between the free end ( 22 ) of the divider ( 20 ) and the second short side ( 6   b ) towards the first short side ( 6   a ) between the second side of the divider ( 20 ) and the other long side ( 5   b ), which first short side ( 6   a ) is also adjacent to the second porthole ( 8 ), whereby said second throughflow duct ( 15 ) thus extends in a U shape from the first porthole ( 7 ) round the divider ( 20 ) and back on the other side of the divider ( 20 ) to the second porthole ( 8 ). 
   
   
       7 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that a third edge region ( 23 ) of the first plate type ( 3 ) is disposed in the second plane ( 13 ) of the first plate type ( 3 ) and extends round said plate type ( 3 ) both along each long side ( 5   a, b ) and along each short side ( 6   a, b ), which edge regions ( 23 ) constitute an abutment surface against the edge regions ( 23 ) of the second plate type ( 4 ) which are disposed on the second plate type ( 4 ) in a corresponding manner, which second plate type ( 4 ) is placed under the first plate type ( 3 ) in the plate stack ( 2 ). 
   
   
       8 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that each plate type ( 3 ,  4 ) has a rim ( 24 ) disposed on each short side ( 6   a, b ). 
   
   
       9 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that a number of distribution ducts ( 26   a - d ) are disposed in a region where the dimples ( 11 ) are adjacent to the edge region ( 18 ,  19 ) of a porthole ( 7 ,  8 ), whereby said distribution ducts ( 26   a - d ) communicate with the respective portholes ( 7 ,  8 ) to which the respective distribution ducts ( 26   a - d ) lead. 
   
   
       10 . A heat exchanger ( 1 ) according to  claim 8 , characterised in that a draining duct ( 25 ) is disposed in the rim ( 24 ) or in the immediate vicinity of the rim ( 24 ) and communicates with throughflow ducts ( 14 ,  15 ) formed between two adjacent plate types ( 3 ,  4 ). 
   
   
       11 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that the configuration of the pattern ( 10   a, b ) of dimples ( 11 ) of the first plate type ( 3 ) is such that the peaks of two adjacent dimples ( 11 ) which point in the same direction have, disposed between them at a level below the peaks, a valley situated higher than the bottoms of two other adjacent dimples ( 11 ), which bottoms point in the opposite direction from that of the peaks. 
   
   
       12 . A heat exchanger ( 1 ) according to  claim 1 , characterised in that the dimples ( 11 ) of the second plate type ( 4 ) point on side A from the second plane ( 13 ) towards the first plane ( 12 ).