Brazing joints

Abstract

One aspect provides a header tube and a refrigeration tube that have ends on which one or more coupling ends are integrally formed thereon. Methods of fabricating the header tube and refrigeration tube are also provided.

1 . A refrigerant coil, comprising:
 a header tube, said header tube having an integrally formed coupling end, said coupling end having a first non-flared section at an end of said header tube joined by a tapered shoulder to a second non-flared section wherein an internal diameter of said first section is less than an internal diameter of said second section.   
     
     
         2 . The refrigerant coil recited in  claim 1 , wherein a ratio of said internal diameter of said first section to said internal diameter of said second section is less than  1 . 
     
     
         3 . The refrigerant coil recited in  claim 2 , wherein said ratio is about 0.97. 
     
     
         4 . The refrigerant coil recited in  claim 1 , wherein said coupling end comprises aluminum and further comprising a copper connecting tube having an end positioned within said coupling end, said copper connecting tube having an external diameter that is less than said internal diameter of said first section and said internal diameter of said second section and wherein said copper connecting tube seats on an internal shoulder of said first section at a junction point of said header tube and said coupling end. 
     
     
         5 . The refrigerant coil recited in  claim 4 , wherein a brazing solder is located only between said external diameter of said copper connecting tube and said internal diameter of said second section. 
     
     
         6 . The refrigerant coil recited in  claim 4 , wherein a difference between said internal diameter of said first section and said external diameter of said connecting tube ranges from about 0.002″ to about 0.006″. 
     
     
         7 . A method of manufacturing a refrigerant coil, comprising:
 cutting a refrigerant header tube to a predetermined length having first and second ends; and   shaping at least one of said first and second ends to form a coupling end, said coupling end having first and second non-flared sections joined by a tapered shoulder wherein an internal diameter of said first section is less than an internal diameter of said second section.   
     
     
         8 . The method recited in  claim 7 , wherein shaping includes shaping said internal diameter of said first section and said internal diameter said second section such that a ratio of said internal diameter of said first section to said internal diameter of said second section is less than 1. 
     
     
         9 . The method recited in  claim 8 , wherein said ratio is about 0.97. 
     
     
         10 . The method recited in  claim 7 , wherein said coupling ends comprise aluminum and said method further comprising,
 positioning an end of a connecting tube comprising copper within said coupling end such that said connecting tube seats on an internal should of said first section, said connecting tube having an external diameter that is less than said internal diameter of said first section and said internal diameter of said second section; and   brazing said connecting tube to said coupling end such that brazing solder is located only between said external diameter of said connecting tube and said internal diameter of said second section.   
     
     
         11 . A refrigeration coil, comprising:
 a refrigeration tube having first and second longitudinal sections having a first rounded corner located therebetween and having first and second ends, respectively, at least one of said first and second ends comprising an integrally formed coupling end having:
 a first flared section located adjacent said first end and having a first internal diameter that graduates from a first, smaller internal diameter to a second, larger internal diameter; 
 a second non-flared section joining said first section and having a second internal diameter larger than said first smaller internal diameter; 
 a third flared section joining said second section and having a third internal diameter that graduates from a third smaller diameter to a fourth internal diameter that is larger than said second internal diameter; and 
   a header plate located adjacent said first and second ends and wherein said first and second longitudinal sections extend through openings located in said header plate.   
     
     
         12 . The refrigeration coil recited in  claim 11 , wherein each of said first and second ends comprises said coupling end, and further comprising a second rounded corner that is brazed to each of said coupling ends. 
     
     
         13 . The refrigeration coil recited in  claim 11 , wherein said first and third flared sections each include an angled wall, wherein a ratio of said angled wall of said first flared section to said angled wall of said third flared section ranges from about 0.71 to about 0.90. 
     
     
         14 . The refrigeration coil recited in  claim 13 , wherein said ratio is about 0.9. 
     
     
         15 . The refrigeration coil recited in  claim 11 , wherein said refrigeration tube has a length that extends from said first rounded corner to said coupling end, and wherein said coupling end extends from said header plate a distance, wherein said distance ranges from about 0.65 to about 0.75 inches. 
     
     
         16 . The refrigeration coil recited in  claim 11 , wherein a difference between the internal diameter of the non-flared section and the external diameter of the connecting return bend ranges from about 0.001″ to about 0.003″. 
     
     
         17 . The refrigeration coil recited in  claim 15 , wherein said distance is about 0.72 inches. 
     
     
         18 . A method of fabricating a refrigeration coil, comprising:
 forming a refrigeration tube having first and second longitudinal sections joined by a first rounded corner, said first and second longitudinal sections having first and second ends, respectively;   positioning said first and second ends through openings in a header plate to a predetermined distance;   shaping a coupling end on each of said first and second ends, said coupling ends each having a first flared section located at said first end and having a first internal diameter that graduates from a first, smaller internal diameter to a second, larger internal diameter, a second section joining said first section and having a second internal diameter larger than said first smaller internal diameter, and a third flared section joining said second section and having a third internal diameter that graduates from a third smaller diameter to a fourth internal diameter that is larger than said second internal diameter; and   brazing a second rounded corner to each of said coupling ends.   
     
     
         19 . The method recited in  claim 17 , wherein shaping said first and third flared sections includes forming an angled wall, wherein a ratio of said angled wall of said first internal diameter to said angled wall of said third internal diameter ranges from about 0.71 to about 0.90. 
     
     
         20 . The method recited in  claim 17 , wherein said refrigeration tube has a length extending from said first rounded corner to said coupling ends wherein said the distance is about from 0.65 to 0.75 inches. 
     
     
         21 . The refrigeration coil recited in  claim 17 , wherein a difference between the internal diameter of the non-flared section and the external diameter of the connecting return bend ranges from about 0.001″ to about 0.003″. 
     
     
         22 . The method recited in  claim 20 , wherein said distance is about 0.72 inches.