HEAT EXCHANGER

摘要

First heat transfer plates (S1) and second heat transfer plates (S2) are folded, respectively, along crest folding lines (L1) and root folding lines (L2) in a zigzag fashion and what are so folded are jointed to the inner circumferential surface of an outer casing (6) and the outer circumferential surface of an inner casing (7) in such a manner that the first heat transfer plates and second heat transfer plates are disposed in a radial direction, whereby a combustion gas passageway and an air passageway are alternately formed in a circumferential direction. One ends of the combustion gas passageway and air passageway are cut in a crest fashion, and an inlet (11) for the combustion gas passageway and an outlet (16) for the air passageway are formed by closing one side and the other side thereof. An outlet for the combustion gas passageway and an inlet for the air passageway are formed, respectively, at the other ends of the combustion gas passageway and the air passageway in a similar manner, thereby making it possible to provide a heat exchanger that is simple in construction and easy to fabricate and which can restrain the loss in pressure due to the curved flow passageways to a minimum level.