Heat exchanger

Abstract

An object of the present invention is to provide a heat exchanger that can be used in an air separation unit including a low-pressure column, a high-pressure column, and a mixing column, and that can suppress increases in equipment costs. The present invention provides a heat exchanger used in an air separation unit ( 1100 ) including a low-pressure column ( 600 ), a high-pressure column ( 500 ), and a mixing column ( 400 ), wherein the heat exchanger is composed of plates and fins, and wherein a warm gas which is at least a part (at least one of W 1 , W 2 , W 3 ) of a feed air and at least one warm liquid (at least one of W 4 and W 5 ) which is led out from the mixing column ( 400 ) are cooled by at least one cold gas (at least one of C 2 and C 3 ) which is led out from the low-pressure column ( 600 ) and a cold gas (C 1 ) which is led out from the mixing column ( 400 ), and a cold liquid (C 6 ) which is led out from the low-pressure column ( 600 ) through a pressure boosting pump ( 800 ) and supplied to the mixing column ( 400 ) is heated.

1 . A heat exchanger used in an air separation unit including a low-pressure column, a high-pressure column, and a mixing column,
 wherein the heat exchanger is composed of plates and fins, and   wherein a warm gas which is at least a part of a feed air and at least one warm liquid which is led out from the mixing column are cooled by at least one cold gas which is led out from the low-pressure column and a cold gas which is led out from the mixing column, and a cold liquid which is led out from the low-pressure column through a pressure boosting pump and supplied to the mixing column is heated.   
     
     
         2 . The heat exchanger according to  claim 1 ,
 wherein at least one warm liquid which is led out from the high-pressure column is cooled.   
     
     
         3 . The heat exchanger according to  claim 1 ,
 wherein the heat exchanger further includes a cold liquid passage through which the cold liquid flows, a cold gas passage through which the cold gas flows, a warm liquid passage through which the warm liquid flows, and a warm gas passage through which the warm gas flows, and
 wherein the warm gas passage is arranged so that the warm gas flows in a counter-flow to the cold liquid and the cold gas, and the warm liquid passage is arranged so that the warm liquid flows in a cross-flow to the cold liquid and the cold gas.