Heat exchanger and ribs

Abstract

A heat exchange rib through which a gaseous medium flows to be in heat exchange with another medium. The rib is a strip adapted to receive flow of the gaseous medium along the surfaces thereof, wherein the strip has a first thickness and an edge portion of the strip has a second thickness greater than the first thickness. The edge portion extends in the flow direction of the gaseous medium a width sufficient to increase the average temperature difference between the media.

1 . A heat exchange rib through which a gaseous medium flows to be in heat exchange with another medium, said rib comprising a strip adapted to receive flow of said gaseous medium along the surfaces thereof, wherein said strip has a first thickness and an edge portion of the strip has a second thickness greater than said first thickness, said edge portion extending in the flow direction of the gaseous medium a width sufficient to increase the average temperature difference between the media.  
   
   
       2 . The heat exchanger rib of  claim 1 , wherein said gaseous medium flows from front to back of said rib, and said edge portion is the front portion of the rib.  
   
   
       3 . The heat exchanger rib of  claim 1 , wherein the first thickness of the sheet material is generally in the range from 0.04-0.15 mm, and said second thickness is generally double said first thickness.  
   
   
       4 . The heat exchanger rib of  claim 1 , wherein said second thickness is substantially a multiple of said first thickness, and said edge portion is formed by one or more folds of said rib strip.  
   
   
       5 . The heat exchanger rib of  claim 1 , wherein said edge portion comprises combined strips having at least two different wall thicknesses.  
   
   
       6 . The heat exchanger rib of  claim 1 , further comprising cuts in said ribs adapted to cause turbulence in the gaseous medium flowing along the rib surfaces.  
   
   
       7 . The heat exchanger rib of  claim 6 , wherein said cuts are in said edge portion.  
   
   
       8 . The heat exchanger rib of  claim 1 , wherein the width of the edge portion in the flow direction is about 5-60% of the total width of the rib.  
   
   
       9 . The heat exchanger rib of  claim 8 , wherein the width of the edge portion in the flow direction is about 10-30% of the total width of the rib.  
   
   
       10 . The heat exchanger rib of  claim 1 , wherein said rib is flat.  
   
   
       11 . The heat exchanger rib of  claim 1 , wherein said rib is corrugated and the height of the corrugations is about 3-10 mm.  
   
   
       12 . A heat exchanger comprising ribs according to  claim 1  and flat tubes adapted to carry said other medium, said ribs being disposed between the flat tubes.