Abstract: A compact, low-cost and thermally efficient multi-plate heat exchanger includes a plurality of stamped plates that are stacked adjacent one another in a compact configuration. The plates each have a thin, flat body portion and a sidewall. Inlet and outlet passages are provided in the plates to direct first and second fluids through the stack. The plates are mechanically formed to emboss the plates around the passages. The respective passages for the first fluid are embossed on one direction, while the respective passages for the second fluid are embossed in another direction. The embossing alternates between plates, such that ring grooves are formed between the plates where it is desired to fluidly communicate with a respective passage. A high efficiency, extended surface fin structure and a pair of flow rings are located on each plate. The flow rings are located in the ring grooves for directing fluid between the respective plates.

Abstract: A holding fixture for use in the brazing of heat exchangers applying multiple holding pressures, two of which are in senses opposed to one another. Cage members mount a heat exchanger between them and are biased in a separating sense. At the same time they incorporate apparatus to apply a clamping pressure essentially within respective cage members. Fixture mechanism includes a detachable part useful as a reactant member in application of the clamping pressure and as a dynamic retainer in applying a pressure in conjunction with a separating motion of the cage members. The invention has method aspects related to brazing in the presence of multiple applied pressures.