Heat exchanger, method of manufacture and tube plate therefor

Abstract

This invention relates to a heat exchanger, to a method of manufacturing the heat exchanger, and to a tube plate for use in the heat exchanger. The heat exchanger is particularly suited for radiators for motor vehicles. The heat exchanger comprises an array of tubes, at least one end of each tube being sealingly connected to a tube plate, the tube plate having a first tube plate wall and a second tube plate wall with a gap between the tube plate walls, each of the first tube plate wall and the second tube plate wall having an opening to receive the end of a tube, the gap between the tube plate walls providing a chamber for containing a sealing material. There is also provided a method of making a heat exchanger including the step is injecting a settable sealing material into the chamber defined by the tube plate walls.

1 . A heat exchanger comprising an array of tubes, at least one end of each tube being sealingly connected to a tube plate, the tube plate having a first tube plate wall and a second tube plate wall with a gap between the tube plate walls, each of the first tube plate wall and the second tube plate wall having an opening to receive the end of a tube, the gap between the tube plate walls providing a chamber for containing a sealing material.  
   
   
       2 . A heat exchanger according to  claim 1  wherein the tube plate is part of a header.  
   
   
       3 . A heat exchanger according to  claim 1  wherein the tube plate is formed as an extrusion.  
   
   
       4 . A heat exchanger according to  claim 1  wherein there is an interference fit between the tube ends and the tube plate openings.  
   
   
       5 . A heat exchanger according to  claim 1  wherein the chamber has a first hole for the injection of the sealing material.  
   
   
       6 . A heat exchanger according to  claim 5  wherein the chamber has a second hole to allow the escape of air during injection and the escape of sealing material when the chamber has been filled with sealing material.  
   
   
       7 . A heat exchanger according to  claim 1  wherein the tube carries a number of extended surface members, and wherein the end-most extended surface member engages the first tube plate wall.  
   
   
       8 . A heat exchanger according to  claim 1  comprising two headers, a number of tubes sealingly connected to both headers, and a number of extended surface members carried by each of the tubes, each header having a respective tube plate, wherein the headers, including the tube plates, the tube(s) and the extended surface member(s) are of aluminium.  
   
   
       9 . A heat exchanger according to  claim 1  wherein the first tube plate wall is manufactured separately from the second tube plate wall.  
   
   
       10 . A heat exchanger according to  claim 1  wherein the sealing material is two-pack silicon elastomer.  
   
   
       11 . A tube plate for use in a heat exchanger, the tube plate having a first tube plate wall and a second tube plate wall with a gap between the tube plate walls, each of the first tube plate wall and the second tube plate wall having an opening to receive the end of a tube, the gap between the tube plate walls providing a chamber for containing a sealing material.  
   
   
       12 . A method of assembling a heat exchanger, the heat exchanger comprising an array of tubes, an end of each tube being sealingly connected to a tube plate, the tube plate having a first tube plate wall and a second tube plate wall, there being a gap between the tube plate walls defining at least one chamber of the tube plate, each of the first tube plate wall and the second tube plate wall having an opening to receive an end of a tube, the method including the steps of {i} inserting an end of each tube into respective openings in the first and second tube plate walls, the end of each tube passing through the chamber, {ii} providing an injection opening in the chamber, {iii} injecting a settable sealing material into the chamber through the respective injection opening, and {iv} allowing the sealing material to set so as to seal the end(s) of the tube(s) in the tube plate.  
   
   
       13 . A method according to  claim 12  wherein the tubes are fitted with extended surface members as a preliminary assembly step.  
   
   
       14 . A method according to  claim 12  including a control step of comparing the actual volume of settable sealing liquid injected against the expected volume in order to check for leaks.  
   
   
       15 . A method according to  claim 12  wherein the settable sealing material is liquid rubber.