Heat-exchange fin for a brazed-plate heat exchanger, and corresponding heat exchanger

Abstract

A fin ( 9 ) includes a perforated and/or recessed corrugated product which has a main direction of corrugation (F 1 ) and which is bounded by two lateral edges ( 13 ). The main direction of corrugation (F 1 ) is oblique with respect to the two lateral edges ( 13 ). The fin is useful in the main heat-exchange lines of air distillation plants.

1 . Heat-exchange fin for a brazed-plate heat exchanger, of the type comprising a perforated and/or recessed corrugated product which has a main direction of corrugation (F 1 ) and which is bounded by two lateral edges ( 13 ), characterized in that the main direction of corrugation (F 1 ) is oblique with respect to the two lateral edges ( 13 ).  
     
     
         2 . Fin according to  claim 1 , characterized in that it has an overall direction (F 2 ) of least resistance to the flow of a fluid which makes a substantial angle with the main direction of corrugation (F 1 ).  
     
     
         3 . Fin according to  claim 2 , characterized in that the overall direction (F 2 ) of least resistance to the flow of a fluid is approximately parallel to the two lateral edges ( 13 ).  
     
     
         4 . Fin according to either of claims  2  and  3 , characterized in that it includes, on its wave legs ( 17 ), features ( 18 ;  20 ;  21 ) which favour movement of the fluid transversely to the overall direction (F 2 ) of least resistance to the flow.  
     
     
         5 . Fin according to one of  claims 1  to  4 , characterized in that it includes, on its wave legs ( 17 ), features ( 18 ;  20 ;  21 ) for creating turbulence in the fluid.  
     
     
         6 . Fin according to  claim 4  or  5 , characterized in that the features ( 18 ) consist of openings provided on that side of the wave legs ( 17 ) which receives the fluid flow, these openings being open towards the upstream of this flow.  
     
     
         7 . Fin according to  claim 4  or  5 , of the serrated type, characterized in that the features consist of tabs ( 20 ) projecting on that side of the wave legs ( 17 ) which receives the fluid flow.  
     
     
         8 . Fin according to  claim 7 , characterized in that the tabs ( 20 ) are provided on the leading edge of the wave legs ( 17 ).  
     
     
         9 . Fin according to  claim 4  or  5 , of the serrated type, characterized in that the features consist of indentations ( 21 ) on the leading edges and/or trailing edges of the wave legs ( 17 ), these indentations being provided on the offset lines ( 19 ) of the fin ( 9 ) so as to increase the flow area for the fluid in a direction which, compared with the main direction of corrugation (F 1 ), approaches the direction (F 2 ) of the said lateral edges ( 13 ).  
     
     
         10 . Brazed-plate heat exchanger of the type comprising a plurality of parallel rectangular plates ( 2 ) which between them define passages ( 3 ,  4 ,  5 ) of flat overall shape and, in each passage, a heat-exchange fin ( 9 ), each fin forming a spacer between two plates, together with lateral closure bars ( 6 ), characterized in that at least one heat-exchange fin ( 9 ) is in accordance with any one of  claims 1  to  9 .  
     
     
         11 . Heat exchanger according to  claim 10 , characterized in that it constitutes a main heat-exchange line of an air distillation plant.