Removable Flow Diversion Baffles for Liquefied Natural Gas Heat Exchangers

Abstract

The invention relates to liquefied natural gas. Particularly, the invention relates to indirect heat exchange means utilized in liquefaction processes. Specifically, the invention relates to the utilization of flow diversion plates within heat exchangers.

1 . A heat exchanger comprising:
 a. a pressure containing shell defining an internal volume, wherein the shell further includes an interior radius and an exterior radius;   b. at least one brazed aluminum plate-fin core disposed in the internal volume;   c. a plate strip, wherein the radius of plate strip is identical to the interior radius of the shell, wherein the plate strip is welded to the interior radius of the shell, said plate strip further includes a bolt pattern;   d. a removable flow diversion plate, wherein the flow diversion plate includes a bolt pattern identical to the bolt pattern of the plate strip; and   e. a fastener means to secure the removable flow diversion plate to the plate strip.   
     
     
         2 . The heat exchanger according to  claim 1 , wherein the fastener means includes at least one nut and at least one bolt. 
     
     
         3 . The heat exchanger according to  claim 2 , wherein at least one bolt is placed through the bolt patter of the plate step and the flow diversion plate and at least one nut is used to secure at least one bolt in place. 
     
     
         4 . The heat exchanger according to  claim 1 , wherein the plate strip is about ¾″ thick and about 2″ radial width. 
     
     
         5 . The heat exchanger according to  claim 1 , wherein the series of nuts and bolts are made of the same material as the shell. 
     
     
         6 . The heat exchanger according to  claim 1 , wherein the series of nuts and bolts are made of austenitic stainless steel. 
     
     
         7 . The heat exchanger according to  claim 1 , wherein the series of nuts and bolts are made of the ASME SA-320 Grade B8 stainless steel. 
     
     
         8 . The heat exchanger according to  claim 1 , wherein the series of bolts are stud bolts. 
     
     
         9 . The heat exchanger according to  claim 1 , wherein the nuts are double-nutted using heavy hex nuts to ensure the removable flow diversion plates are securely attached to the plate strip. 
     
     
         10 . The heat exchanger according to  claim 1 , wherein the internal volume has a height-to-width ratio greater than 1. 
     
     
         11 . The heat exchanger according to  claim 1 , wherein the heat exchanger is a plate-fin heat exchanger. 
     
     
         12 . The heat exchanger according to  claim 1 , wherein the heat exchanger is brazed aluminum heat exchanger. 
     
     
         13 . A method of transferring heat from a refrigerant to a cooled fluid, said method comprising:
 a. introducing the refrigerant into an internal volume defined within a shell, the internal volume having a height-to-width ration greater than 1;   b. utilizing a removable flow diversion plate attached to a plate strip to divert the flow of the cooled fluid within the internal volume of the shell,
 wherein the radius of plate strip is identical to the interior radius of the shell, 
 wherein the plate strip is welded to the interior radius of the shell, 
 said plate strip further includes a bolt pattern, 
 wherein the removable flow diversion plate includes a bolt pattern identical to the bolt pattern of the plate strip, 
 wherein a series of bolts are placed through the of bolt pattern of the plate strip and the removable flow diversion plate and a series of nuts are used to secure the bolts in plate; 
   c. introducing the cooled fluid into a plate-fin core disposed within the internal volume of the shell;   d. transferring heat from the cooled fluid in the core to the refrigerant in the shell via indirect heat exchange; and   e. withdrawing a predominately vapor stream of the refrigerant from dedicated vapor outlet nozzles in the shell,
 said core defining a plurality of shell-side flow passageways for receiving said refrigerant. 
   
     
     
         14 . The method according to  claim 13 , wherein the height-to-width ratio being at least about 1.25. 
     
     
         15 . The method according to  claim 13 , step (c) including vaporizing at least a portion of said refrigerant in said shell-side passageways. 
     
     
         16 . The method according to  claim 13 ; and (f) maintaining the level of liquid-phase refrigerant said in said shell where at least 50% of the height of the core is submerged in the liquid-phase refrigerant. 
     
     
         17 . The method according to  claim 13 , according to step (f) including maintaining the level of liquid-phase refrigerant said in said shell where at least 75-95% of the height of the core is submerged in the liquid-phase refrigerant. 
     
     
         18 . The method according to  claim 17 , step (a) including introducing said refrigerant into the internal volume at a location above the level of liquid phase refrigerant in the shell. 
     
     
         19 . The method according to  claim 13 , wherein the plate strip is about ¾″ thick and about 2″ radial width. 
     
     
         20 . The method according to  claim 13 , wherein the series of nuts and bolts are made of the same material as the shell. 
     
     
         21 . The method according to  claim 13 , wherein the series of nuts and bolts are made of austenitic stainless steel. 
     
     
         22 . The method according to  claim 13 , wherein the series of nuts and bolts are made of the ASME SA-320 Grade B8 stainless steel. 
     
     
         23 . The method according to  claim 13 , wherein the series of bolts are stud bolts. 
     
     
         24 . The method according to  claim 12 , wherein the nuts are double-nutted using heavy hex nuts to ensure the removable flow diversion plates are securely attached to the plate strip. 
     
     
         25 . The method according to  claim 13 , wherein the internal volume has a height-to-width ratio greater than 1. 
     
     
         26 . The method according to  claim 13 , wherein the heat exchanger is brazed aluminum heat exchanger.