A plate type heat exchanger, comprising:
- a plurality of coupled plate pairs with each pair comprising an upper plate and a lower plate, each plate of said pair having a substantially planar portion, two longitudinal edges extending the length of the plate and two end edges joining said longitudinal edges, the plates of each pair being sealably coupled together, wherein the planar portions are spaced apart thereby enclosing a longitudinal flow passageway extending therebetween and forming spaces between adjacent plate pairs defining lateral air passageways;
- the plates each being provided with at least two apertures therethrough, said apertures being spaced apart in the longitudinal direction of the plate and spaced from the end edges of the plate, each aperture in one plate being substantially in registration with an aperture in said other plate in said plate pair;
- the plates being formed with connecting portions peripherally encircling each aperture and extending transversely from the plates;
- said plurality of plate pairs being stacked together in spaced apart relationship, wherein each connecting portion extending from a plate pair is connected to a connecting portion extending from an adjacent plate pair to form a sealable coupling, said connecting portions together enclosing substantially transverse flow passageways, said transverse flow passageways being spaced apart and in flow communication with the lateral flow passageways;
- means defining an inlet port in flow communication with one of said transverse passageways, and means defining an outlet port in flow communication with another of said transverse passageways;
- the transverse passageways having end portions and means for closing said end portions not in flow communication with the inlet and outlet ports;
- and
- fins located in said lateral air passageways, said fins being in thermal contact with the plates, and having transverse fluid passageways extending therethrough, wherein said connecting portions are tubes, said sealable coupling includes an overlapping portion which overlaps a portion of at least one of said tubes, the tubes of each upper plate project upwardly from the respective upper plate and tubes of each lower plate project in the opposite transverse direction from the respective lower plate, neither said tubes nor said plate pairs in the region of said apertures being formed with spacing means to position the tube of each upper plate with respect to the tube of the lower plate connected thereto in the axial direction of the tubes and outer end sections of said fins are located laterally adjacent said tubes or longitudinally outwardly from said tubes on the sides thereof located away from the longitudinal center of the adjacent plates, the lateral location of said outer end sections being in a direction perpendicular to the longitudinal edges of the plates.