Production of cross-flow heat exchanger, particularly steam condenser for domestic clothes drier - has folded up edges joined together and in which counter-sunk holes and rows of cupped and perforated impressions are punched before over-moulding with polymer

摘要

Cross-flow device for exchanging heat between two media, particularly a steam condensing device for a domestic appliance, is produced by cutting thin, planar, rectangular, metal foils or sheets (50), folding up their opposite edges (55,56) in a mutually different direction, stacking an even number of the foils and joining the folded edges of adjoining pairs together, clamping the stack in an injection mould, and over-moulding the stack with a polymer having low linear shrinkage so as to form frame-shaped head portions (63) enclosing the inlets and outlets of channels (61) for one of the two media. Before clamping the injection mould the thin metal foils are subjected to punching so as to obtain rows of countersunk holes (56) along the folded-up edges (55,56), at least two rows of cupped and perforated impressions (57) running parallel to the orthogonal sides of the foils, and through-holes (58) at the points where the rows of impressions meet. As a result of the over-moulding, perpendicular strips (51,52) are formed which remain attached to the countersunk holes (56) and at least two patterns of ribs (53,54) extending within the stack perpendicular to the planes of the channels (61,62) of the two media which remain attached to the cupped and perforated impressions (57) and intersect each other with at least a bead of polymer extending over the entire height of the stack at the through-holes (58) punched n the foils. Also claimed is the cross-flow device produced by the above method.