Fin-tube heat exchanger collar, and method of making same

Abstract

A collar for a fin-tube heat exchanger is provided. The collar extends outwardly from a thermally conductive plate in order to receive a tube. The collar generally includes a wall having a proximal end integral to the conductive plate, and a distal end defining an opening configured for receiving a tube. The wall includes a reflare portion at its distal end, with the reflare portion being curled into either the inner diameter or the outer diameter of the wall. Preferably, the reflare portion is curled into the inner diameter of the wall, and then further flared outwardly to form a double flare. A method for forming the double flare collar is also provided. The method involves progressively moving fin stock through a metal-stamping machine in order to sequentially form double flare collars.

1 . A collar for a fin-tube heat exchanger, the collar extending outwardly from a thermally conductive plate, the collar comprising: 
 a radial wall drawn from the thermally conductive plate and defining an opening dimensioned to receive a tube; and    the wall having a proximal end integral to the wall and a distal end curled back into contact with the wall so as to form a first flare.    
   
   
       2 . The collar of  claim 1 , wherein the radial wall is substantially circular in profile.  
   
   
       3 . The collar of  claim 1 , wherein the radial wall is substantially oval in profile.  
   
   
       4 . The collar of  claim 1 , wherein the first flare is curled inwardly into an inner diameter of the wall.  
   
   
       5 . The collar of  claim 4 , wherein the distal end has a greater outer diameter than an outer diameter of the proximal end, thereby forming a double flare.  
   
   
       6 . The collar of  claim 1 , wherein the first flare is curled outwardly into an outer diameter of the wall.  
   
   
       7 . The collar of  claim 6 , wherein the distal end has a greater outer diameter than the proximal end, thereby forming a double flare.  
   
   
       8 . A collar for a fin-tube heat exchanger, the collar extending outwardly from a thermally conductive plate, the collar comprising: 
 a wall drawn from the thermally conductive plate and defining an opening dimensioned to receive a tube, the wall having a circular profile;    the wall having a proximal end integral to the wall and a distal end curled inwardly back into contact with an inner diameter of the wall so as to form a first flare; and    the distal end of the wall having a greater outer diameter than an outer diameter of the proximal end, thereby forming a double flare collar.    
   
   
       9 . A fin for a fin-tube heat exchanger, comprising: 
 a thermally conductive plate; and    a plurality of double flare collars within the plate forming an array, each collar comprising a radial wall drawn from the plate and defining an opening dimensioned to receive a tube, each wall having a proximal end integral to the plate and a distal end curled back into contact with the wall so as to form a first flare, and the distal end of each respective wall being flared outwardly to provide a greater outer diameter than an outer diameter of the respective proximal ends of the walls.    
   
   
       10 . A fin-tube heat exchanger, comprising: 
 at least one elongated tube, the tube having an outer diameter;    a plurality of thermally conductive parallel plates;    a substantially cylindrical wall extending from each of the plates, each wall defining a proximal end integral to the conductive plate, and a distal end forming an opening configured for receiving the tube; and    the distal end of each wall being curled back into contact with its respective wall so as to form a first flare, and having a greater outer diameter than an outer diameter of the respective proximal ends, thereby forming a plurality of double flare collars.    
   
   
       11 . The fin-tube heat exchanger of  claim 10 , wherein each of the walls has a substantially circular profile.  
   
   
       12 . The fin-tube heat exchanger of  claim 11 , wherein: 
 each of the plates comprises an array of substantially cylindrical walls drawn from the plates and defining double flare collars for receiving a plurality of respective tubes; and    the tubes being expanded into frictional engagement with surrounding walls of the corresponding collars.    
   
   
       13 . A method for forming collars in a thermally conductive plate, comprising the steps of: 
 placing a thermally conductive plate within a press;    advancing the plate through the press in order to form a plurality of through-openings in the plate, each through-opening defining a radial wall having a distal end; and    further advancing the plate through the press so as to curl the distal end into contact with the radial wall, thereby forming collars having a first flare.    
   
   
       14 . The method of  claim 13 , wherein each of the walls has a substantially circular profile.  
   
   
       15 . The method of  claim 13 , further comprising the step of: 
 further advancing the plate through the press so as to expand the outer diameter of each of the walls at its distal end, thereby forming a plurality of double flare collars.    
   
   
       16 . The method of  claim 15 ,: 
 wherein each of the plurality of through-openings is dimensioned to receive an expandable tube; and    further comprising the step of inserting a tube through at least one of the plurality of through-openings.    
   
   
       17 . The method of  claim 16 , further comprising the step of: 
 expanding a portion of the tube into frictional engagement with a surrounding wall in the collar.    
   
   
       18 . A method for forming a plurality of collars in a thermally conductive plate, comprising the steps of: 
 placing a thermally conductive plate within a press;    advancing the plate through the press in order to form a plurality of through-openings in the plate, each through-opening defining a circular wall dimensioned to receive a tube;    further advancing the plate through the press so as to form a first flare at the distal end of each of the plurality of walls whereby the distal end of the wall is curled back into its respective wall; and    further advancing the plate through the press so as to form an outward flare at the distal end of each of the plurality of walls such that the outer diameter of the distal end of each wall is expanded, thereby forming a plurality of double flare collars.    
   
   
       19 . The method of  claim 18 , wherein the step of forming a plurality of cylindrical through-openings in the plate comprises using a pierce punch to pierce through-openings through the plate, each through-opening having a proximal end integral to the plate having a first diameter, and a distal end having a second smaller diameter.  
   
   
       20 . The method of  claim 19 , wherein the step of forming a first flare at the distal end of each of the plurality of walls comprises moving a reflare punch down onto the distal end of each of the walls, the reflare punch having a tip with a diameter that is larger than the second diameter of each of the walls, thereby forming an inward flare.  
   
   
       21 . The method of  claim 20 , wherein the step of forming an outward flare at the distal end of each of the plurality of walls comprises further moving the reflare punch downward onto the distal end of the walls so as to enlarge the second diameter.