Apparatus for cooling exhaust

Abstract

An apparatus for cooling exhaust gas cooling the exhaust gas re-circulated includes an exhaust gas passage; at least one first cooling portion; and at least one second cooling portion, wherein the first cooling portion and the second cooling portion are made of different materials.

1 . An apparatus for cooling exhaust gas cooling the exhaust gas re-circulated comprising:
 an exhaust gas passage in which the exhaust gas flows;   at least one first cooling portion comprising a coolant inlet and an exhaust gas inlet for cooling the exhaust gas; and   at least one second cooling portion comprising a coolant outlet and an exhaust gas outlet for cooling the exhaust gas cooled from the first cooling portion,   wherein the first cooling portion and the second cooling portion are made of different materials.   
   
   
       2 . The apparatus of  claim 1 , wherein:
 the heat conductivity of the first cooling portion and the heat conductivity of the second cooling portion are different.   
   
   
       3 . The apparatus of  claim 2 , wherein:
 the first cooling portion comprises,   a plurality of first plates contacting coolant;   a plurality of second plates disposed in the first plates; and   a fin made of a steel material and disposed between the second plates.   
   
   
       4 . The apparatus of  claim 2 , wherein:
 the second cooling portion comprises,   a plurality of first plate contacting coolant;   a plurality of second plates disposed in the first plates; and   a fin made of a steel material and disposed between the second plates.   
   
   
       5 . The apparatus of  claim 1 , wherein:
 a gasket is disposed between the first cooling portion and the second cooling portion.