Abstract: A heat exchanger (100) for an exhaust gas recirculation system includes one or more rigid tubes (103), each having one or more internal cooling fins (111) that act as heat exchange surfaces to transfer heat from a gas to the walls of the rigid tubes. The rigid tubes are cooled by a liquid coolant contained within an outer jacket (113) surrounding the tubes. The rigid tubes may be straight and smooth, and may be alternated with one or more bellows sections (108, 104) which provide flexibility to the heat exchanger.

Abstract: An improved heat exchanger suitable for use as a pre-cooler in an internal combustion engine exhaust gas recirculation system includes an inner heat exchange tube for exchanging heat between a gas and a coolant. A tubular outer body surrounds at least part of the inner heat exchange tube. Coolant flows through a cavity formed between the outer surface of the inner heat exchange tube and the inner surface of the tubular outer body, cooling the gas flowing through the inner heat exchange tube. The inner heat exchange tube surrounds a rolled, cylindrically-shaped corrugated sheet of material forming a plurality of fins. At least one of the fins is in contact with an inner surface of the inner heat exchange tube. The tubular outer body surrounds two or more inner heat exchange tubes, each inner heat exchange tube surrounding a respective plurality of fins.

Abstract: An improved heat exchanger suitable for use as a pre cooler in an internal combustion engine exhaust gas recirculation system comprises an inner heat exchange tube for exchanging heat between said gas and said liquid coolant. A tubular outer body may surround at least part of the inner heat exchange tube. Liquid coolant may flow through a cavity formed between the outer surface of the inner heat exchange tube and the inner surface of the tubular outer body, cooling gas flowing through the inner heat exchange tube. The inner heat exchange tube may surround a substantially cylindrical corrugated sheet of material forming a plurality of fins. At least one of the fins may be in contact with an inner surface of the inner heat exchange tube. The tubular outer body may surround two or more inner heat exchange tubes, each inner heat exchange tube surrounding a respective plurality of fins.

Abstract: A heat exchanger (100) suitable for use as a pre cooler in an internal combustion engine exhaust gas recirculation system comprises one or a plurality of rigid tubes (103), each having one or more internal cooling fins (111) to act as heat exchange surfaces to transfer heat from a gas to the walls of the rigid tubes. The rigid tubes are cooled by a liquid coolant surrounding the tubes and contained within an outer jacket (113) surrounding said tubes. The rigid tubes may be straight and smooth, and may be alternated with one or a plurality of bellows sections (108, 104) which provide flexibility to the heat exchanger.