Folded, bent and re-expanded heat exchanger tube and assemblies

Abstract

A heat exchanger assembly of the side-entry type includes at least one fin set and an elongated heat exchanger tube having one or more collapsed sidewall portions extending substantially the length of the tube. The folded tube is first bent to form the return bend portions and then is expanded to engage the fin set. Methods of making the elongated heat exchanger tube having one or more collapsed sidewall portion methods of making heat exchanger assemblies are also disclosed.

1 . For use in the heat exchanger assembly of a side entry type having at least one fin set, an elongated heat exchanger tube having at least two collapsed sidewall portions extending substantially the length of said tube, the elongated heat exchanger tube being adapted to being bent to form a return bend portion and then being expanded to engage and secure the tube in a passage in a fin set.  
     
     
         2 . The tube of  claim 1  wherein said elongated heat exchanger tube has a wall thickness of between about 0.010 to 0.030 inches.  
     
     
         3 . The tube of  claim 1  wherein the one or more collapsed sidewall portions comprises an elongated recess extending substantially the length of said heat exchanger tube.  
     
     
         4 . The tube of  claim 1  wherein the one or more collapsed sidewall portions comprise a pair of opposed elongated recesses extending substantially the length of said heat exchanger tube.  
     
     
         5 . An elongated heat exchanger tube comprising: 
 an elongated tube having first and second ends and an internal passageway extending between the first and second ends, said elongated tube being formed from a sidewall;    at least two collapsed portions of the sidewall of the elongated heat exchanger tube extending substantially along a length of the elongated tube, the two collapsed portions contacting each other within the passageway of the tube; and    the at least two collapsed portions of the sidewall of the elongated tube being expandable radially outward to push the at least two collapsed sidewall portions outward so that they no longer contact each other and the passageway within the tube is opened.    
     
     
         6 . The tube of claim  31  wherein the at least two collapsed portions define at least two elongated recesses extending substantially along a length of the elongated tube.  
     
     
         7 . The tube of claim  31  wherein the at least two collapsed portions of the side wall of the elongated tube are each form a portion of the sidewall that is bent into a generally U-shaped configuration having two sides and a bottom, and the bottoms of the U-shaped configurations of the at least two collapsed portions contact each other.