Heat exchanger with varying tube design

Abstract

A shell and tube heat exchanger includes a plurality of tubes positioned inside a shell. A first type of tube has a first outer surface, and a second type of tube has a second outer surface, where the first outer surface is different than the second outer surface. The inner surface of the first type of tube is in liquid communication with the inner surface of the second type of tube, so fluid can flow between the inner surfaces of the different tube types.

1 . A horizontal shell and tube heat exchanger comprising:
 a shell having a bottom;   a process fluid outlet penetrating the bottom of the shell;   a first tube positioned inside the shell, the first tube having a first outer surface; and   a second tube positioned inside the shell, the second tube having a second outer surface different than the first outer surface.   
   
   
       2 . The shell and tube heat exchanger of  claim 1  wherein the first tube is positioned above the second tube. 
   
   
       3 . The shell and tube heat exchanger of  claim 1  where the first outer surface is a two dimensional outer surface and the second outer surface is a three dimensional outer surface. 
   
   
       4 . The shell and tube heat exchanger of  claim 3  where the second outer surface is a three dimensional outer surface. 
   
   
       5 . The shell and tube heat exchanger of  claim 1  where the process fluid outlet is in liquid communication with the tube outer surfaces, the shell and tube heat exchanger further comprising a heat transfer fluid inlet, where each tube has an inner surface in liquid communication with the heat transfer fluid inlet. 
   
   
       6 . The shell and tube heat exchanger of  claim 1  where the first tube includes a plurality of first tubes and the second tube includes a plurality of second tubes. 
   
   
       7 . The shell and tube heat exchanger of  claim 1  further comprising a horizontal baffle positioned inside the shell. 
   
   
       8 . The shell and tube heat exchanger of  claim 1  where the first tube has an inner surface, the first tube further comprising a ridge defined on the first tube inner surface. 
   
   
       9 . A shell and tube heat exchanger comprising:
 a shell;   a first tube positioned inside the shell, the first tube having a first outer surface and an inner surface; and   a second tube positioned inside the shell, the second tube having a second outer surface different than the first outer surface, and the second tube having an inner surface in liquid communication with the first tube inner surface.   
   
   
       10 . The shell and tube heat exchanger of  claim 9  further comprising a process fluid outlet in liquid communication with the first outer surface and the second outer surface, where the shell includes a bottom and the process fluid outlet penetrates the shell bottom. 
   
   
       11 . The shell and tube heat exchanger of  claim 9  where the first outer surface is a two dimensional outer surface. 
   
   
       12 . The shell and tube heat exchanger of  claim 9  where the first tube includes a plurality of first tubes defining a first heat exchanger section and where the second tube includes a plurality of second tubes defining a second heat exchanger section below the first heat exchanger section. 
   
   
       13 . The shell and tube heat exchanger of  claim 9  further comprising a third tube having a third outer surface different than the first outer surface and the second outer surface, where the third tube is positioned below both the first tube and the second tube. 
   
   
       14 . The shell and tube heat exchanger of  claim 9  further comprising a helical ridge defined on the first tube inner surface. 
   
   
       15 . A shell and tube heat exchanger comprising:
 a shell;   a first tube positioned inside the shell, the first tube having a first outer surface and an inner surface;   a second tube positioned inside the shell, the second tube having a second outer surface different than the first outer surface, and the second tube having an inner surface;   a heat transfer fluid outlet penetrating the shell, the heat transfer fluid outlet in liquid communication with the first and second tube inner surfaces; and   a process fluid outlet penetrating the shell, the process fluid outlet in liquid communication with the first and second tube outer surfaces.   
   
   
       16 . The shell and tube heat exchanger of  claim 15  further comprising a tube sheet positioned inside the shell, where every tube penetrates the tube sheet, and the tube sheet provides a barrier between the process fluid outlet and the heat transfer fluid outlet. 
   
   
       17 . The shell and tube heat exchanger of  claim 15  where the tubes are approximately horizontal inside the shell, the shell includes a bottom, and the process fluid outlet penetrates the shell bottom. 
   
   
       18 . The shell and tube heat exchanger of  claim 15  further comprising a longitudinal baffle positioned over the process fluid outlet. 
   
   
       19 . The shell and tube heat exchanger of  claim 15  where one of the first and second tubes is a two dimensional tube, and the other of the first and second tubes is a three dimensional tube. 
   
   
       20 . A shell and tube condenser comprising:
 Means for increasing heat transfer rates by varying the heat transfer surfaces in the heat exchanger.