Finned tube heat exchanger

Abstract

A heat exchanger comprises a tube and fins extending from an outer surface of the tube in a helical path. The fins comprise serrated sections and solid sections that are disposed in a predetermined arrangement along the helical path.

1 . A heat exchanger, comprising:
 a tube; and   fins extending from an outer surface of the tube in a helical path, the fins comprise serrated sections and solid sections that are disposed in a predetermined arrangement along the helical path.   
     
     
         2 . The heat exchanger of  claim 1 , wherein the serrated sections and the solid sections are alternately disposed along the helical path. 
     
     
         3 . The heat exchanger of  claim 1 , wherein a portion of the serrated sections are directly in the path of a free stream. 
     
     
         4 . The heat exchanger of  claim 1 , wherein a portion of the solid sections are directly in the path of a free stream. 
     
     
         5 . The heat exchanger of  claim 1 , wherein the solid sections comprise groove, dimples, corrugations, or other heat transfer enhancing features. 
     
     
         6 . The heat exchanger of  claim 1 , wherein each of the serrated sections includes a plurality of individual fins that extend substantially till the outer surface of the tube. 
     
     
         7 . The heat exchanger of  claim 6 , wherein the fins comprise a fin strip that is helically wound and attached to the outer surface of the tube, with slits created on the fin strip corresponding to the serrated sections before helically winding the fin strip. 
     
     
         8 . A heat exchanger, comprising:
 a tube; and   fins extending from an outer surface of the tube in a helical path, the fins comprise serrated sections and solid sections that are alternately disposed along the helical path, wherein the tube is positioned such that a portion of either the serrated sections or the solid sections are directly in the path of a free stream.   
     
     
         9 . The heat exchanger of  claim 8 , wherein the solid sections comprise groove, dimples, corrugations, or other heat transfer enhancing features. 
     
     
         10 . The heat exchanger of  claim 8 , wherein each of the serrated sections includes a plurality of individual fins that extend substantially till the outer surface of the tube. 
     
     
         11 . The heat exchanger of  claim 10 , wherein the fins comprise a fin strip that is helically wound and attached to the outer surface of the tube, with slits created on the fin strip corresponding to the serrated sections before helically winding the fin strip.