Fin tube assembly for air cooled heat exchanger and method of manufacturing the same

Abstract

A finned tube assembly for an air cooled condenser. The finned tube assembly comprises a non-circular core tube and at least one set of fins that are welded directly to the core tube. The core tube can be formed by a plurality of longitudinal transverse sections that are seam welded together. In another embodiment, the invention is a fined tube assembly having an outer surface that is made corrosion resistant by a surface conversion process, such as ferretic nitrocarburization.

1 . A fin tube assembly for an air-cooled heat exchanger comprising:
 a core tube having an internal passageway for carrying a fluid to be cooled, the core tube having a non-circular transverse cross-section; and   at least one set of fins welded to an outside surface of the core tube.   
   
   
       2 . The fin tube assembly of  claim 1  wherein the at least one set of fins is a corrugated sheet having peaks terminating in ridges and valleys terminating in floors. 
   
   
       3 . The fin tube assembly of  claim 2  wherein the floors of the valleys of the corrugated sheet are contiguously laser welded to the outside surface of the core tube. 
   
   
       4 . The fin tube assembly of  claim 3  wherein the floors of the valleys comprise a substantially flat section that is contiguously laser welded to the outside surface of the core tube. 
   
   
       5 . The fin tube assembly of  claim 2  wherein the floors of the valleys of the corrugated sheet are laser welded in a stitched manner to the outside surface of the core tube. 
   
   
       6 . The fin tube assembly of  claim 1  wherein the at least one set of fins is a corrugated sheet having peaks terminating in ridges and valleys terminating in floors, the peaks and valleys being orthogonally shaped. 
   
   
       7 . The fin tube assembly of  claim 1  wherein the core tube is a single-layer tube and the at least one set of fins is a single layer material. 
   
   
       8 . The fin tube assembly of  claim 1  wherein the core tube is made of carbon steel, stainless steel, aluminum or copper and the at least one set of fins is made of carbon steel, stainless steel, aluminum or copper, the materials of the core tube and the at least one set of fins being metallurgically compatible for welding. 
   
   
       9 . The fin tube assembly of  claim 1  wherein the core tube is a multi-layer tube and the at least one set of fins is a multi-layer material. 
   
   
       10 . The fin tube assembly of  claim 1  further comprising:
 the outside surface of the core tube comprising opposite substantially flat faces; and   a set of fins welded to each of the substantially flat faces.   
   
   
       11 . The fin tube assembly of  claim 1  wherein the at least one set of fins is welded to the outside surface of the core tube using a fusion welding technique that does not use a filler material. 
   
   
       12 . The fin tube assembly of  claim 1  wherein the core tube is constructed of a plurality of plate structures bent into a transverse section of the core tube, the transverse sections arranged in an adjacent manner so that a plurality of longitudinal interfaces exist, the longitudinal interfaces being contiguously welded to form the core tube. 
   
   
       13 . The fin tube assembly of  claim 12  comprising a first plate structure bent into a first transverse section of the core tube and a second plate structure bent into a second transverse section of the core tube, the first and second transverse sections arranged in the adjacent manner so that first and second longitudinal interfaces exist, the first and second longitudinal interfaces being contiguously welded to form the core tube. 
   
   
       14 . The fin tube assembly of claim  23  wherein the first and second longitudinal interfaces are formed by contact between bottom surfaces of lateral flanges formed into the first transverse section and top surfaces of lateral flanges formed into the second transverse section, the lateral flanges being seam welded together. 
   
   
       15 . A fin tube assembly for an air-cooled heat exchanger comprising:
 a core tube having an inner surface forming a passageway for carrying a fluid to be cooled and an outsider surface having a first substantially flat face and a second substantially flat face opposite the first substantially flat face;   the core tube constructed from a first plate structure bent into a first transverse section of the core tube and a second plate structure bent into a second transverse section of the core tube, the first and second transverse sections arranged in an adjacent manner so that first and second longitudinal interfaces exist, the first and second longitudinal interfaces being contiguously welded to form the core tube;   at least one of the first or second longitudinal interfaces formed by either (1) contact between lateral edges of the first and second transverse sections, the lateral edges being butt welded together, or (2) contact between bottom surfaces of lateral flanges formed into the first transverse section and top surfaces of lateral flanges formed into the second transverse section, the lateral flanges being fusion welded together; and   a set of fins connected to each of the first and second substantially flat faces.   
   
   
       16 . The fin tube assembly of  claim 15  wherein both the first or second longitudinal interfaces are formed by contact between the bottom surfaces of lateral flanges formed into the first transverse section and the top surfaces of lateral flanges formed into the second transverse section. 
   
   
       17 . The fin tube assembly of  claim 16  wherein the lateral flanges of the first and second transverse sections extend inward toward the passageway, the first and second lateral flanges being seam welded together. 
   
   
       18 . The fin tube assembly of  claim 16  further comprising:
 the sets of fins being corrugated sheets having peaks terminating in ridges and valleys terminating in floors; and   the sets of fins welded to the first and second substantially flat faces along the floors using a fusion welding technique that does not use a filler material.   
   
   
       19 . A fin tube assembly for an air-cooled heat exchanger comprising:
 a core tube having an inner surface that forms an internal passageway for carrying a fluid to be cooled;   at least one set of fins connected to an outside surface of the core tube; and   wherein the outside surface of the core tube and the at least one set of fins is subjected to a ferretic nitrocarburization process.   
   
   
       20 . The fin tube assembly of claim  92  wherein the core tube and the at least one set of fins are constructed of steel.