Heat exchanger core having expanded metal heat transfer surfaces

Claim 1

A heat exchanger core for transferring heat between at least two counterflowing fluid streams comprising a plurality of high conductivity expanded metal members, each such member with a mechanically continuous structure having a plurality of interstices and having approximately 70 percent open area, said interstices having major and minor axes, a plurality of low conductivity thermoplastic separators interleaved with said expanded metal members, each separator having a rectangular shape and a peripheral portion and transverse elements defining fluid flow channels, said separator members and said expanded metal members oriented with respect to each other such that the major axes of said interstices are perpendicular to said transverse portions, the material of the separator penetrating the interstices of the expanded metal members at the points of contact between the expanded metal members and peripheral portion and transverse elements of the separators, the separator material thereby bonding the separator to the expanded metal members, and the separators being aligned, thereby providing at least a pair of mutually isolated fluid flow channels through the heat exchanger core.