Brazed plate fin heat exchanger

Abstract

A fin collar having a shape that enhances flux application and brazing clad flow into the tube to fin joint to provide an improved thermal and structural bond.

1 . A heat exchanger, comprising: 
 at least one plate fin having a first side, a second side, and at least one opening defined therein;    at least one fin collar disposed on the plate fin around the at least one opening, the fin collar having an upstanding wall extending from the plate fin, the wall having a plurality of slits defined therein; and,    at least one tube for conveying a pressurized fluid, the tube being disposed through the at least one opening in the plate fin.    
   
   
       2 . The heat exchanger of  claim 1 , wherein the at least one tube has a cross-sectional shape that is round.  
   
   
       3 . The heat exchanger of  claim 1 , wherein the at least one tube has a cross-sectional shape that is circular.  
   
   
       4 . The heat exchanger of  claim 1 , wherein the at least one tube has a cross-sectional shape that is oval.  
   
   
       5 . The heat exchanger of  claim 1 , wherein the plurality of slits are disposed substantially equidistantly around a perimeter of the collar.  
   
   
       6 . The heat exchanger of  claim 1 , wherein the plurality of slits are defined by a pair of opposed walls that are angled such that the slit is wider at a point distal to the plate fin than it is at a point proximal to the plate fin.  
   
   
       7 . The heat exchanger of  claim 1 , wherein the plurality of slits have a rectangular shape.  
   
   
       8 . The heat exchanger of  claim 1 , wherein the at least one fin collar is constructed of an aluminum alloy.  
   
   
       9 . The heat exchanger of  claim 8 , further comprising a cladding layer.  
   
   
       10 . The heat exchanger of  claim 1 , wherein the at least one tube is constructed of an aluminum alloy.  
   
   
       11 . The heat exchanger of  claim 1 , wherein the at least one plate fin is attached to the at least one tube by brazing.  
   
   
       12 . The heat exchanger of  claim 1 , wherein the at least one plate fin is attached to the at least one tube by brazing in a controlled atmosphere brazing oven.  
   
   
       13 . The heat exchanger of  claim 1 , wherein the at least one tube is constructed of copper.  
   
   
       14 . The heat exchanger of  claim 1 , wherein the at least one plate fin is constructed of copper.  
   
   
       15 . The heat exchanger of  claim 1 , wherein the fin collar is unclad.  
   
   
       16 . A heat exchanger, comprising: 
 at least one plate fin having a first side, a second side and at least one opening defined therein;    at least one fin collar disposed on the plate fin around the at least one opening, the fin collar having an upstanding wall extending from the plate fin, the wall having a plurality of slits defined therein; and,    at least one tube for conveying a pressurized fluid, the tube being disposed through the opening in the plate fin and attached to the fin collar by brazing.    
   
   
       17 . The heat exchanger of  claim 16 , wherein the at least one tube has a cross-sectional shape that is round.  
   
   
       18 . The heat exchanger of  claim 16 , wherein the at least one tube has a cross-sectional shape that is circular.  
   
   
       19 . The heat exchanger of  claim 16 , wherein the at least one tube has a cross-sectional shape that is oval.  
   
   
       20 . The heat exchanger of  claim 16 , wherein the plurality of slits are disposed substantially equidistantly around a perimeter of the collar.  
   
   
       21 . The heat exchanger of  claim 16 , wherein the plurality of slits are defined by a pair of opposed walls that are angled such that the slit is wider at a point distal to the plate fin than it is at a point proximal to the plate fin.  
   
   
       22 . The heat exchanger of  claim 16 , wherein the plurality of slits have a rectangular shape.  
   
   
       23 . The heat exchanger of  claim 16 , wherein the at least one fin collar is constructed of an aluminum alloy.  
   
   
       24 . The heat exchanger of  claim 23 , further comprising a cladding layer.  
   
   
       25 . The heat exchanger of  claim 16 , wherein the at least one tube is constructed of an aluminum alloy.  
   
   
       26 . The heat exchanger of  claim 16 , wherein the at least one fin collar is attached to the at least one tube by brazing.  
   
   
       27 . The heat exchanger of  claim 16 , wherein the at least one plate fin is attached to the at least one tube by brazing in a controlled atmosphere brazing oven.  
   
   
       28 . The heat exchanger of  claim 16 , wherein the at least one tube is constructed of copper.  
   
   
       29 . The heat exchanger of  claim 16 , wherein the at least one plate fin is constructed of copper.  
   
   
       30 . The heat exchanger of  claim 16 , wherein the fin collar is unclad.  
   
   
       31 . A method of forming a plate fin heat exchanger, comprising: 
 providing at least one plate fin having a first side, a second side, and at least one opening; at least one fin collar disposed on the plate fin around the at least one opening, the fin collar having an upstanding wall extending from the plate fin, the wall having a plurality of slits defined therein; and at least one tube for conveying a pressurized fluid, the tube being disposed through the at least one opening and attached to the fin collar by brazing;    providing a cladding material for brazing the plate fin-to-tube joint; and,    brazing the plate fin-to-tube joint in a controlled atmosphere brazing oven.