Abstract: Two identically folded strips enclose an intermediate space accessible at e edges of the strip, and the fold cavities opening to the outside of the strip structure are closed off at the strip edges and covered by outside cover plates over their central portions, so that one medium may be caused to flow through each of the sets of outside fold cavities and a third medium through the intermediate space. The third medium flows countercurrent to the direction of flow of the other two. Modules of four such matrices utilize inlet and outlet ducts so that the two or four matrices in a compact modular structure can be structurally repeated in accordance with the number of modules desired in the particular application. The inlet and outlet ducts have tapering flow cross-sections.

Abstract: Heat exchanger matrices of the folded strip type are set in an elongated V onfiguration inside a tubular casing. They are held in position by braces between opposite cover plates and between other cover plates and the casing, which braces also operate as partition walls for separating inlet and outlet channels of one of the media. The cooler of the media has inlet ducts downwards on the edges of the space inside the V and an outlet duct for upward flow at the center of the space inside the V. The other medium, which is hotter, but under less pressure, has inlet ducts with upward flow at the center of the spaces outside the V and outlet ducts with downward flow at the edges of the spaces outside the V. The hotter parts of the heat exchanger are in the middle of the structure. Bellows-type thermal expansion compensators seal the edges of the V against the casing.