Patent ID: 7191824

Claim:
A heat exchanger comprising: (a) an outer tube having an outer surface; (b) an inner tube received inside the outer tube and concentric therewith, wherein an axial fluid flow passageway is formed between the inner and outer tubes; (c) a first inlet and a first outlet in fluid communication with the axial passageway, the first inlet and the first outlet being axially spaced from one another; (d) at least one circumferential fluid flow passageway being formed along the outer surface of the outer tube; and (e) a corrugated strip fin being arranged in each of said at least one circumferential fluid flow passageways, each of said strip fins comprising a plurality of rows of corrugations, the corrugations each comprising a top portion, a bottom portion and a side wall connecting the top and bottom portions, the bottom portions of at least some of the corrugations being in contact with the outer tube; wherein the corrugated strip fins are arranged in the circumferential fluid flow passageways in a low pressure drop orientation with rows of corrugations in the corrugated strip fins extending axially through the circumferential flow passageways and with apertures through the corrugations extending circumferentially.