Heat exchangers

Abstract

A baffle for a shell and tube heat exchanger comprises a one piece helical flight extending from a central core. The helical flight has a plurality of aligned openings for receiving tubes of the heat exchanger. The helical flight may be made by machining from a casting or solid block of material, or by an additive manufacturing process.

1 . A baffle for a shell and tube heat exchanger comprising:
 a one piece helical flight extending from a central core, the helical flight having a plurality of openings therethrough for forming a plurality of fluid flow passages through the flight.   
     
     
         2 . A baffle as claimed in  claim 1 , wherein the core is a hollow core, or is a solid core. 
     
     
         3 . A baffle as claimed in  claim 1 , wherein the helical flight is integrally formed with the core, or is formed separately from and attached to the core. 
     
     
         4 . A baffle as claimed in  claim 1  further comprising:
 a plurality of tubes mounted through the openings in the flight for conducting fluid therethrough. 
 
     
     
         5 . A baffle as claimed in  claim 1 , further comprising;
 a plurality of tubes integrally formed with the flight and aligned with the openings in the flight for conducting fluid therethrough.   
     
     
         6 . A shell and tube heat exchanger comprising;
 a shell having an inlet and an outlet for a first fluid;   a plurality of tubes extending through the shell and having an inlet and outlet for a second fluid; and   a baffle as claimed in any preceding claim arranged in said shell said tubes extending through or aligning with the plurality of openings in the helical flight.   
     
     
         7 . A method of manufacturing a heat exchanger baffle comprising a helical flight extending from a central core, comprising;
 forming the helical flight as a single continuous piece; and   forming a plurality of holes in the flight for forming a fluid flow passage through the flight.   
     
     
         8 . A method as claimed in  claim 7 , wherein the helical flight is integrally formed with the core. 
     
     
         9 . A method as claimed in  claim 7 , comprising providing a rough casting of the helical flight, machining the rough casting to a final shape, and forming the holes in the flight either before or after machining the flight. 
     
     
         10 . A method as claimed in  claim 7 , comprising providing a block of material, for example a cylindrical block, machining the block to produce a flight having a final shape, and forming the holes in the flight either before or after machining the flight. 
     
     
         11 . A method as claimed in  claim 9 , wherein the holes are formed by drilling. 
     
     
         12 . A method as claimed in  claim 7 , comprising manufacturing the helical flight by an additive manufacturing process. 
     
     
         13 . A method as claimed in  claim 12 , comprising forming the holes simultaneously with the flight by the additive manufacturing process. 
     
     
         14 . A method as claimed in  claims 13 , further comprising forming a plurality of tubes in alignment with and joining the holes simultaneously with the flight by the additive manufacturing process. 
     
     
         15 . A method of manufacturing a heat exchanger comprising manufacturing a helical baffle by a method as claimed in  claim 12 , and forming a heat exchanger body around the helical baffle simultaneously with the flight by the additive manufacturing process.