Heat exchanger assembly designed as a longitudinal counterflow device

摘要

A heat exchanger assembly of the counterflow type having a vertically extending longitudinal configuration is constructed from a plurality of individual tube nests, with each of the nests formed of a plurality of individual tubes adapted to have a first heat exchange medium flow therethrough. The upper and lower ends of the tubes are connected to tube plates and a guide shell is provided surrounding each of the tube nests for effecting therein flow of a secondary heat exchange medium around the individual tubes of each nest. Each of the tube nests is formed by its associated guide shell and tube plates as an individual box with the boxes thus formed when viewed in a plane extending transversely to the longitudinal direction of the heat exchanger assembly being arranged as a hexagonal grid. The tube plates are positioned in a staggered arrangement with each tube plate longitudinally spaced from an adjacent tube plate so that they may be overlapping when seen in plan view thereby reducing the space requirements of the overall assembly. The boxes are welded to a supporting structure located in the bottom region of the assembly and a housing is provided surrounding the hexagonal grid of boxes in order to form together with the supporting structure a tight joint to enclose the assembly. A central guide shell located within the midsection of the hexagonal grid and surrounded by the boxes encloses therein a plurality of return tubes for returning to the tubes of the tube nests a first heat exchange medium flowing therethrough. The central guide shell is enclosed by a hood through which the return tubes extend with the return tubes being welded to the hood.