Abstract: An exhaust gas recirculation cooler, typically of the drawn cup design, with a bypass and control valve is disclosed. The control valve can direct a proportion of the exhaust gas to the cooler and a proportion to bypass the cooler depending on the input temperature of the exhaust gas and the required temperature of the exhaust gas. The proportion of the exhaust gas directed to the cooler/bypassing the cooler can be varied as required and so the temperature of the exhaust gas can be controlled. One benefit of certain embodiments of the invention is that engine damaging chemicals, such as sulphuric acid, which result from over-cooling the exhaust gas are reduced.

Abstract: A heat exchanger includes a core with a plurality of passages arranged therein each having an opening positioned adjacent an end portion of the core. A manifold is positioned adjacent the core end portion and includes an inlet and an outlet opening. The manifold includes a divider wall that extends internally therein and that forms separated inlet and outlet passages that are in communication with the respective inlet and outlet openings. The heat exchanger includes a metallic seal interposed between the divider wall and the core to provide a seal therebetween. The seal is constructed to impose a biasing force between the divider wall and the core to provide the desired seal, thereby minimizing or eliminating any unwanted bypass of fluid or gas within the manifold during heat exchanger operation and increasing heat exchanger operating efficiency.

Abstract: A heat exchanger tube is provided that includes an inner diameter, an outer diameter and a longitudinal axis. The heat exchanger includes at least two spiral upsets protruding from the inner diameter of the tube and spiraling around the longitudinal axis of a length of the tube. The at least two spiral upsets include a first spiral upset having a cross-sectional shape, a depth of protrusion from the inner diameter, a pitch, and an angle with respect to the longitudinal axis, and a second spiral upset having a cross-sectional shape, a depth of protrusion from the inner diameter, a pitch, and an angle with respect to the longitudinal axis. In one embodiment, the angle of the first spiral upset with respect to the longitudinal axis is approximately equal to the angle of the second spiral upset with respect to the longitudinal axis, such that the first and second spiral upsets are approximately parallel.

Abstract: Thermal indictors of this invention are constructed for use with a heat exchanger generally comprising hot and cold side passages for accommodating a desired heat transfer therebetween. The thermal indicator is disposed at least partially within the heat exchanger and is formed from a material designed to undergo a permanent physical change when exposed to a temperature that is above a heat exchanger design operating temperature.