A system and method for the concurrent condensation of a nitrogen-rich vapor and vaporization of an oxygen-rich liquid in a distillation column based air separation unit is provided. The disclosed system includes a condenser-reboiler heat exchanger located between a lower pressure column and a higher pressure column and configured to condense a nitrogen-rich vapor from the higher pressure column and partially vaporize an oxygen-rich liquid from the lower pressure column. Within the condenser-reboiler heat exchanger, the nitrogen-rich vapor flows in an upward direction such that any non-condensables present in the nitrogen-rich vapor will accumulate proximate the upper portion or top of the condenser-reboiler modules where they can be easily removed through venting.

In a method and apparatus for passing a mixed vapour and liquid stream between a first heat exchanger (101) and a second heat exchanger (102) the mixed vapour and liquid stream outflows from the first heat exchanger (101) through two or more outlets (104). Then, the mixed vapour and liquid stream in the outlets (104) passes through two or more intermediate conduits (103) to the second heat exchanger (102), after which the mixed vapour and liquid stream inflows from the intermediate conduits (103) into the second heat exchanger (102) through two or more inlets (105). The number (X) of outlets (104) is equal to or greater than the number (Y) of inlets (105).

Provided is a cooling device with which it is possible to cool a fluid to be cooled, even before maintenance work, if a fault such as a blockage or a breakage occurs in a part of a channel. The cooling device (1) is provided with four heat exchangers (1A-1D) and a plurality of heat exchanger connection parts (111-120), each of the heat exchanger connection parts allowing natural gas to flow therethrough. Each of the heat exchangers has: a drum (101, 102, 103, fourth drum 104), a refrigerant reservoir (T), a plurality of heat exchanger core parts (121, 122, 123, 124) immersed in liquid propane in the refrigerant reservoir (T), and a demister (106). A plurality of cooling channels allowing natural gas to flow therethrough are installed, independent of each other, from the first heat exchanger (1A) to the fourth heat exchanger (1D).

A sinusoidal corrugated tube-type spiral wounded heat exchanger suitable for FLNG, wherein a top of an outer cylinder has a shell-side refrigerant inlet and a bottom thereof has a shell-side refrigerant outlet; a sinusoidal corrugated tube-type liquid distributor is below the shell-side refrigerant inlet, a first sinusoidal corrugated winding tube bundle and a second sinusoidal corrugated winding tube bundle, which are heat exchanger tubes with a sinusoidal wave shape, are inside the outer cylinder, and peaks and troughs of the first sinusoidal corrugated winding tube bundle and the second sinusoidal corrugated winding tube bundle are in staggered correspondence one by one from top to bottom; a sinusoidal corrugated tube-type liquid distributor includes a one-into-two-type tube, a two-into-four-type tube, two sinusoidal corrugated tube-type liquid distribution tubes from top to bottom.