Abstract: Plate-and-fin core-type heat exchangers are installed within pressure vessels in a manner which eliminates the need for distributors, collectors, headers, nozzles, and manifolds at the feed inlet, the processed gas outlet, or both the feed inlet and the processed gas outlet of each exchanger core. The heat exchangers can be installed in parallel or in series within a single pressure vessel. Alternatively, the heat exchangers can be installed in pressure vessels which are arranged in series such that multiple liquid product streams can be obtained. The heat exchangers preferably are operated in the condensing mode in which feed gas is cooled and partially condensed. The operation of the heat exchangers is characterized by the cocurrent flow of the condensate and uncondensed feed gas, preferably in the vertical or near-vertical direction. In an alternative embodiment, the heat exchangers are operated such that a feed fluid is cooled without phase change.

Abstract: Dephlegmator system without headers, collectors, or distributors at the bottom end of feed circuits in plate and fin exchangers operating in condensing or rectifying service. Each dephlegmator is installed within a pressure vessel, thereby eliminating the need for headers, collectors, or distributors at the bottom end of the feed circuits. In an alternative embodiment of the invention, upper and lower segments of the pressure vessel are isolated by a mid-vessel seal between the vessel and dephlegmator walls, and headers or collectors are not required at the upper and lower ends of the feed circuits.