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 W1, W2, W3) of a feed air and at least one warm liquid (at least one of W4 and W5) which is led out from the mixing column (400) are cooled by at least one cold gas (at least one of C2 and C3) which is led out from the low-pressure column (600) and a cold gas (C1) which is led out from the mixing column (400), and a cold liquid (C6) 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.

Dependencies are inferred from the claim text.