Heat exchanger construction

A heat exchanger comprising a casing and a matrix, said matrix being enclosed within said casing, said matrix comprising a stack of primary plates;

• spacer means constituted by sheets of corrugated material, said corrugated material being so disposed that the peaks of the corrugations thereof engage and are attached to said primary plates;
• and corrugated enclosing members, the planes of the peaks of the corrugations in said enclosing members extending in directions which are generally normal to said primary plates;
• each of said plates being held in spaced apart relationship from adjacent plates by said spacer means so that alternate flow paths for first and second heat exchange fluids respectively are defined by said plates, the peripheries of at least alternate pairs of adjacent plates being interconnected by said enclosing members so that the flow paths for the first of said heat exchange fluids are not in flow communication with the flow paths for the second of said heat exchange fluids, fluid delivery and exhaust means being respectively provided for each of said first and second fluids to direct said fluids into their respective flow paths within said matrix and exhaust said fluids from those flow paths, said second heat exchange fluid operationally flowing through said casing, said matrix being so arranged that said second heat exchange fluid flows through the appropriate flow paths in said matrix on its passage through said casing.