Concentric tube heat exchanger end seal therefor

Abstract

A concentric tube heat exchanger comprises an outer tube and a concentric inner tube, with an annular passageway between the tubes. The ends of the annular passageway are sealed by sealing members having axially extending inner and outer walls which are connected to one another and which are sealed to the respective outer and inner tubes. The sealing member walls are preferably connected by an integrally formed connecting wall. The walls of the sealing member are preferably resilient and diverge so as to form a friction fit with the tubes during assembly of the heat exchanger. The heat exchanger further comprises a turbulizer which comprises a plurality of rows of corrugations defining axially extending flow passages. Preferably, the corrugations have a top land width greater than a bottom land width so that the side walls of the corrugation are radially arranged in the annular passageway. Adjacent corrugations in each row are preferably offset relative to one another by an amount of from about 30 percent to about 40 percent.

1 - 17 . (canceled)  
   
   
       18 . A sealing member for sealing an annular gap between inner and outer axially-extending tubes of a concentric tube heat exchanger, the sealing member comprising: 
 an outer wall having first and second axially-spaced ends and having a generally axially-extending portion between its ends for sealing to the outer tube; and    an inner wall having first and second axially-spaced ends, the inner wall being connected to the outer wall and being spaced radially inwardly of the outer wall, the inner wall having a generally axially-extending portion between its ends for sealing to the inner tube;    wherein the generally axially-extending portions of the walls diverge from one another along said axis.    
   
   
       19 . The sealing member of  claim 18 , wherein the inner and outer walls are connected through a connecting portion, the second ends of the sealing member walls are axially spaced from the connecting portion which seals a radial space between the sealing member walls.  
   
   
       20 . The sealing member of  claim 18 , wherein the generally axially-extending portions of the walls are resilient, and wherein the generally axially-extending portions diverge from one another at an angle such that, when the sealing member is received in the annular gap with the outer wall frictionally engaging the outer tube and the inner wall frictionally engaging the inner tube, and such that the generally axially-extending portions of the sealing member walls are in substantial engagement with the inner and outer tubes.  
   
   
       21 . The sealing member of  claim 18 , wherein the generally axially-extending portion of at least one of the sealing member walls diverges from the axis by an angle of from about 1 to about 2 degrees.  
   
   
       22 . The sealing member of  claim 18 , wherein the generally axially-extending portions of the inner and outer sealing member walls diverge from the axis by an angle of from about 1 to about 2 degrees.  
   
   
       23 . The sealing member of  claim 21 , wherein said angle is about 1.5 degrees.  
   
   
       24 . The sealing member of  claim 22 , wherein said angle is about 1.5 degrees.  
   
   
       25 . The sealing member of  claim 19 , wherein the sealing member is generally U-shaped, with the first ends of the sealing member walls being connected to the connecting portion and the second ends of the sealing member walls being distal to the connecting portion.  
   
   
       26 . The sealing member of  claim 25 , wherein the connecting portion is rounded.  
   
   
       27 . The sealing member of  claim 25 , wherein the connecting portion is flat and extends radially between the inner and outer walls.  
   
   
       28 . The sealing member of  claim 25 , wherein the connecting portion is V-shaped.  
   
   
       29 . The sealing member of  claim 25 , wherein the connecting portion is indented toward the second end of the outer wall.  
   
   
       30 . The sealing member of  claim 19 , wherein the connecting portion is attached to the sealing member walls between the first and second ends, such that the sealing member is generally H-shaped.  
   
   
       31 . The sealing member of  claim 19 , wherein the connecting portion is integrally formed with the sealing member walls.  
   
   
       32 . The sealing member of  claim 18 , wherein the walls are formed from a material which is sufficiently resilient such that the second ends of the first and second walls are compressible toward one another.  
   
   
       33 . The sealing member of  claim 32 , wherein the walls are comprised of aluminum.  
   
   
       34 . A method of manufacturing a concentric tube heat exchanger comprising inner and outer axially-extending tubes and an axially-extending annular passageway between the tubes, the method comprising: 
 (a) providing a pair of annular sealing members, each of the sealing members comprising a resilient outer wall having a first end and a second end, a resilient inner wall having a first and a second end and being spaced from the outer wall, and a connecting portion through which the inner and outer walls are connected;    (b) inserting the sealing members into opposite ends of the annular passageway such that at least a portion of the inner wall and at least a portion of the outer wall of the sealing members are generally axially aligned, wherein the inner and outer walls are compressed toward one another during insertion of the sealing members into the annular passageway, such that the generally axially-aligned portions of the inner and outer walls frictionally engage the inner and outer tubes, respectively; and    (c) expanding the inner tube such that the generally axially-extending portions of the inner and outer walls of the sealing member are parallel to one another and are in substantially complete contact with the inner and outer tubes, respectively.    
   
   
       35 . The method of  claim 34 , wherein the tubes and the sealing members are comprised of aluminum and wherein the method further comprises: 
 (d) brazing the generally axially-extending portions of the sealing member walls to the inner and outer tubes.    
   
   
       36 . The method of  claim 35 , wherein the tubes and/or the sealing members are provided with a cladding comprised of a brazing alloy, at least on surfaces at which the sealing members and the tubes are brazed together.  
   
   
       37 . The method of  claim 34 , wherein the annular passageway has open ends through which the sealing members are inserted, and wherein the sealing members are inserted inwardly of the ends of the annular passageway.