Multiple fluid heat exchanger

A multiple fluid heat exchanger comprising a plurality of longitudinally extending first fluid conducting elements disposed in a stacked relation, a plurality of longitudinally extending second fluid conducting elements disposed in stacked relation with said first fluid elements, said first set of fluid elements including pairs of dished plates joined at their edges and having enlarged openings at each end forming a fluid inlet at one end and a fluid outlet at the opposite end, a first fluid passage in each first element extending between said pairs of openings, second fluid passages formed between said first fluid passages of said first set of elements, said second set of fluid elements including pairs of flat plates joined together with outwardly diverging peripheral edges joined to the peripheral edges of the next adjacent joined pairs of plates and having enlarged openings at each end forming a fluid inlet at one end and a fluid outlet at the opposite end, fluid passages formed between said pairs of joined plates bounded by the joined peripheral edges and extending between said enlarged openings, oppositely raised ribs in each joined pair of plates forming a third fluid passage therein located between said last mentioned fluid passages, raised flanges at each end of said raised ribs defining axially aligned second openings for entrance and exit of said third fluid, said raised flanges of the pairs of joined plates abutting and joined to the raised flanges of the next adjacent pairs of plates, said second openings in said second elements spaced from and located between said enlarged openings in said elements and communicating with said third fluid passages extending therebetween, said enlarged fluid inlets and outlets in said first and second fluid elements being in registry to form at least one fluid inlet chamber and at least one fluid outlet chamber.