Low charge refrigerant flooded evaporator

Abstract

A flooded evaporator has a plurality of tubes extending through a shell. Process fluid flows through the tubes and refrigerant flows inside of the shell through gaps between the tubes. Filler beads are located in the gaps between the tubes, thus displacing some of the refrigerant and requiring a lower refrigerant charge. The refrigerant flows through the spaces between the filler beads. The filler beads move thereby dispersing the refrigerant and dislodging bubbles from the outside of the tubes, resulting in an increase in efficiency of heat exchange.

1 . A flooded shell and tube evaporator, comprising:
 a) a shell having an inlet and an outlet and having a first and second end;   b) a plurality of tubes located in the shell and extending between the first and second ends, the tubes forming a path through the shell, the path comprising at least one pass through the shell;   c) gaps between the tubes;   d) refrigerant located in the shell;   e) filler beads located inside of the shell, the filler beads located in the gaps, the filler beads being smaller than the gaps so as to be able to move through the gaps, the filler beads having a neutral buoyancy relative to the refrigerant.   
   
   
       2 . The evaporator of  claim 1  wherein the filler beads comprise three sizes. 
   
   
       3 . The evaporator of  claim 1  wherein the filler beads are made of plastic. 
   
   
       4 . The evaporator of  claim 1  wherein the filler beads are spherical. 
   
   
       5 . A method of heat exchange in a flooded shell and tube evaporator, comprising the steps of:
 a) providing filler beads inside of the shell and amongst the tubes;   b) flowing a process fluid through the tubes in the evaporator;   c) flowing a refrigerant through the shell and through the spaces between the filler beads and through gaps between the tubes.   
   
   
       6 . The method of  claim 5  further comprising the steps of allowing the beads to move as the refrigerant is flowed, wherein the beads disperse the exchange of heat between the tubes and the refrigerant and the beads contact the tubes and dislodge bubbles on the tubes. 
   
   
       7 . The method of  claim 5  wherein the step of providing filler beads inside of the shell and amongst the tubes further comprises the step of providing filler beads with a neutral buoyancy with respect to the refrigerant.