Patent ID: 7730742

Claim:
A heat transfer device comprising: a tube having a first fluid inlet and a first fluid outlet, the tube arranged to form a plurality of generally parallel elongated segments of the tube, an enclosure enclosing the tube to define at least a part of a flow path for a second fluid over an exterior surface of the tube from a second fluid inlet to a second fluid outlet, a wall interior of the enclosure to define a first section of the flow path for the second fluid in the enclosure which first section leads from the second fluid inlet and extends across at least a first portion of a length of substantially all of the elongated segments of the tube, the wall further defining a second section of the flow path for the second fluid in the enclosure which second section extends across at least a second portion of the length of substantially all of the elongated segments of the tube and leads to the second fluid outlet, the interior wall being shaped and arranged in the enclosure such that a cross sectional area of the flow path for the second fluid in the enclosure changes along its length from the second fluid inlet to the second fluid outlet.