Heat exchanger and method of manufacture

Abstract

This invention relates to a heat exchanger and to a method of manufacturing a heat exchanger. The heat exchanger has a number of tubes and at least one tube plate. The ends of each tube are located in a respective opening in the tube plate(s). The ends of each tube contain a respective insert, the insert acting to expand the end of the tube into sealing engagement with the tube plate.

1 . A heat exchanger comprising a number of tubes and at least one tube plate, the ends of each tube being located within a respective opening in the tube plate(s), the ends of each tube containing a respective insert, the insert acting to expand the end of the tube into sealing engagement with the tube plate. 
     
     
         2 . A heat exchanger according to  claim 1  in which the insert is metallic. 
     
     
         3 . A heat exchanger according to  claim 2  in which the insert is of stainless steel. 
     
     
         4 . A heat exchanger according to  claim 1  in which the external wall of the insert is tapered. 
     
     
         5 . A heat exchanger according to  claim 4  in which the taper angle is 1°. 
     
     
         6 . A heat exchanger according to  claim 1  in which insert has a wall thickness in the range 0.5 mm-1 mm. 
     
     
         7 . A heat exchanger according to  claim 1  in which the tube plate is of metal. 
     
     
         8 . A heat exchanger according to  claim 7  in which the tube plate is of aluminium. 
     
     
         9 . A heat exchanger according to  claim 1  in which the tubes are of metal. 
     
     
         10 . A heat exchanger according to  claim 9 , in which the tubes are made from a material selected from the group comprising: aluminium, copper, titanium, tantalum, and alloys containing these materials. 
     
     
         11 . A heat exchanger according to  claim 9  in which the wall thickness of the tubes is in the range 0.05 mm-1.2 mm. 
     
     
         12 . A heat exchanger according to  claim 1  in which the free end of the insert has a peripheral lip. 
     
     
         13 . A heat exchanger according to  claim 12  in which the peripheral lip of each of the inserts is located in a respective recess in the tube plate. 
     
     
         14 . A method of making a heat exchanger comprising the steps of:
 providing at least one tube plate with a number of openings therethrough;   providing a number of tubes and locating an end of each tube into a respective tube plate opening;   providing a number of inserts and locating an insert into the end of a respective tube within a tube plate opening; and   driving the insert into the end of the tube whereby to expand the end of the tube into sealing engagement with the tube plate.   
     
     
         15 . A method according to  claim 14  which includes the following additional steps:
 providing a header; and 
 securing the header to the tube plate by releasable fastening means. 
 
     
     
         16 . A method according to  claim 15  which includes the following additional steps:
 mounting a number of locating studs upon the tube plate; and 
 providing a number of apertures in the header, each of the apertures being adapted to receive one of a stud and a releasable fastening means. 
 
     
     
         17 . A method according to  claim 15  which includes the following additional steps:
 providing a number of access openings in the header; 
 passing an insert through each of the access openings whereby the insert is located into the end of a respective tube by way of the access opening; 
 passing a driving tool through each of the access openings whereby the insert is driven into the end of the tube by the driving tool; and 
 sealing the access holes.