Abstract: An annular heat exchanger for cooling hot gases comprises an inner shell, an intermediate shell and an outer shell. Where the heat exchanger is integrated with a catalytic converter for treatment of hot exhaust gases in a motor vehicle, the inner shell contains a catalyst for treatment of the exhaust gases. Inner and outer gas flow passages are provided between the shells, and a coolant flow passage is provided, either on the outer surface of the outer shell, or between the intermediate and outer shells. The exhaust gases change direction twice as they pass through the heat exchanger, and the annular structure of the heat exchanger provides a large surface area, and a large flow section, relative to volume, and thereby provides effective heat exchange without significantly increasing space requirements.

Abstract: A device for recovering heat from a hot gas stream comprises a gas diverter valve and a gas/liquid heat exchanger. The diverter valve comprises a valve body; a valve element movable between a bypass position and a heat exchange position; and a gas inlet and a gas outlet formed in the valve body. The heat exchanger comprises a heat exchanger core comprised of a stack of core plates arranged parallel to the exhaust gas flow path, and the heat exchanger is located outside the exhaust gas flow path and may be spaced therefrom so as to avoid unwanted heat transfer with the valve in bypass mode. The heat exchanger may include a bottom-most gas flow path adjacent to the bottom plate, and may include a mounting plate which is mechanically secured to the valve body, with a thermally insulating gasket provided between the mounting plate and the valve body.

Abstract: A heat exchanger apparatus includes a housing that defines a flow passage for a first fluid. The housing has a housing fluid inlet and a housing fluid outlet communicating with the flow passage. A first heat exchanger is located within the flow passage of the housing between the housing fluid inlet and the housing fluid outlet. The first heat exchanger has a plurality of channels for transmitting a second fluid through the first heat exchanger. The heat exchanger apparatus also includes a flow diverter in the flow passage, between the housing fluid inlet and the first heat exchanger, for diverting some of the first fluid to a by-pass region of the flow passage that by-passes the first heat exchanger. As well, a flow control device is in communication with the housing fluid inlet and controls a volume and location of the first fluid entering the flow passage.

Abstract: An annular heat exchanger for cooling hot gases comprises an inner shell, an intermediate shell and an outer shell. Where the heat exchanger is integrated with a catalytic converter for treatment of hot exhaust gases in a motor vehicle, the inner shell contains a catalyst for treatment of the exhaust gases. Inner and outer gas flow passages are provided between the shells, and a coolant flow passage is provided, either on the outer surface of the outer shell, or inbetween the intermediate and outer shells. The exhaust gases change direction twice as they pass through the heat exchanger, and the annular structure of the heat exchanger provides a large surface area, and a large flow section, relative to volume, and thereby provides effective heat exchange without significantly increasing space requirements.

Abstract: A cylindrical heat exchanger for use as a gas cooler in a thermal regenerative machine such as a Stirling engine includes an imperforate middle wall of sufficient strength and thickness to withstand the pressure exerted by the working fluid. The heat exchanger includes an inner corrugated wall located within an axial gas flow passage inside the middle wall, and an outer corrugated wall which defines an axial coolant flow passage along the outer surface of the middle wall. The coolant flow passage preferably contains a corrugated intermediate wall.