Flakt, Ab

Berndt Wadell

Per-Olof Jakobsson

Gosta Jansson

The invention relates to a heat-exchanger (10) incorporating circulation tubes (16) for conducting a first heat-transfer medium, end plates (12), and surface-enlarging plate-like fins (14) secured to the outer peripheral surfaces of the circulation tubes and arranged to be contacted with a second heat-transfer medium, the fins being firmly secured to a plurality of circulation tube sections, which extend through registering holes (18) formed in the fins (14). The fins are secured to the tube sections by expanding the tubes so as to enlarge the periphery thereof. The contact surfaces of the fins about the inside periphery of the holes (18) which engage against the circulation tubes (16) are cylindrical and extend parallel to the longitudinal axis of the circulation tubes over at least a greater part of the axial extent of the holes, which affords stable attachment and good heat-transfer properties. The tube sections may be interconnected to provide the desired flow path(s), by tube elbows welded to the projecting ends of the tube sections. The whole of the heat-exchanger (10) is coated with an impervious, protective surface layer, for example enamel, applied after the tube sections have been expanded to their final configuration.

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Norrkoping, Sweden

Berndt Wadell