Vertical combined feed/effluent heat exchanger with variable baffle angle

Abstract

A shell and tube heat exchanger, such as a vertical combined feed/effluent heat exchanger (VCFE), including: a shell having a fluid inlet and a fluid outlet; a plurality of baffles mounted in the shell to guide the fluid into a helical flow pattern through the shell; wherein a helix angle α of a baffle proximate the inlet is different than a helix angle β of a baffle proximate the outlet.

1 . A heat exchanger comprising:
 a shell having a fluid inlet and a fluid outlet;   a plurality of baffles mounted in the shell to guide the fluid into a helical flow pattern through the shell;   wherein a helix angle α of a baffle proximate the inlet is different than a helix angle β of a baffle proximate the outlet.   
   
   
       2 . The heat exchanger of  claim 1 , wherein helix angle β is less than helix angle α. 
   
   
       3 . The heat exchanger of  claim 1 , wherein helix angle α is less than helix angle β. 
   
   
       4 . The heat exchanger of  claim 1 , wherein the helix angle of the plurality of baffles decreases from the fluid inlet to the fluid outlet. 
   
   
       5 . The heat exchanger of  claim 1 , wherein the helix angle of the plurality of baffles increases from the fluid inlet to the fluid outlet. 
   
   
       6 . The heat exchanger of  claim 1 , wherein a baffle intermediate the baffle proximate the inlet and the baffle proximate the outlet has a helix angle γ intermediate helix angles α and β. 
   
   
       7 . The heat exchanger of  claim 1 , wherein helix angle α is less than helix angle β, and wherein helix angle α is within the range from about 5° to about 35° and wherein helix angle β is within the range from about 15° to about 45°. 
   
   
       8 . The heat exchanger of  claim 7 , wherein helix angle α is within the range from about 5° to about 25°. 
   
   
       9 . A shell and tube heat exchanger comprising:
 an tubeside inlet manifold having a first fluid inlet therein;   an tubeside outlet manifold having a first fluid outlet therein;   a plurality of tubes extending between the manifolds and in fluid communication therewith;   a shell extending between the manifolds and encompassing said tubes, the shell having a second fluid inlet and a second fluid outlet therein;   a plurality of baffles mounted in the shell to guide the second fluid into a helical flow pattern through the shell;   wherein a helix angle α of a baffle proximate the second fluid inlet is different than a helix angle β of a baffle proximate the second fluid outlet.   
   
   
       10 . The heat exchanger of  claim 9 , wherein helix angle β is less than helix angle α. 
   
   
       11 . The heat exchanger of  claim 9 , wherein helix angle α is less than helix angle β. 
   
   
       12 . The heat exchanger of  claim 9 , wherein the helix angle of the plurality of baffles decreases from the fluid inlet to the fluid outlet. 
   
   
       13 . The heat exchanger of  claim 9 , wherein the helix angle of the plurality of baffles increases from the fluid inlet to the fluid outlet. 
   
   
       14 . The heat exchanger of  claim 9 , wherein a baffle intermediate the baffle proximate the inlet and the baffle proximate the outlet has a helix angle γ intermediate helix angles α and β. 
   
   
       15 . The heat exchanger of  claim 9 , wherein helix angle α is less than helix angle β, and wherein helix angle α is within the range from about 5° to about 35° and wherein helix angle β is within the range from about 15° to about 45°. 
   
   
       16 . The heat exchanger of  claim 15 , wherein helix angle α is within the range from about 5° to about 25°. 
   
   
       17 . A process for exchanging heat with a mixed phase fluid, the process comprising:
 feeding a mixed phase fluid comprising a vapor and at least one of an entrained liquid and an entrained solid to a heat exchanger, the heat exchanger comprising:
 a shell having a fluid inlet, and a fluid outlet; 
 a plurality of baffles mounted in the shell to guide the fluid into a helical flow pattern through the shell; 
   converting the mixed phase fluid to essentially all vapor; and   indirectly exchanging heat between the mixed phase fluid and a heat exchange medium;   wherein a helix angle α of a baffle proximate the inlet maintains a velocity of the mixed phase fluid greater than a terminal velocity of the entrained liquid or solid; and   wherein a helix angle β of a baffle proximate the outlet is greater than helix angle α of the baffle proximate the inlet.   
   
   
       18 . The process of  claim 10 , wherein the converting comprises evaporating the entrained liquid. 
   
   
       19 . The process of  claim 10 , wherein the converting comprises combusting the entrained solid. 
   
   
       20 . The heat exchanger of  claim 17 , wherein helix angle α is within the range from about 5° to about 35° and wherein helix angle β is within the range from about 15° to about 45°.