The apparatus and systems are for removing contaminants from an exhaust stream. The process may involve passing at least a portion of an exhaust stream through a cooling component, which draws a cooling stream into the cooling component. The cooling stream interacts with the at least a portion of the exhaust stream to form a mixed stream. The resulting mixed stream is a lower temperature than the at least portion of the exhaust stream.

Systems, methods and apparatus are disclosed that include an exhaust system and an air source external to the exhaust system that is configured to force additional air into the exhaust stream downstream of the engine and aftertreatment system to help mix cool air with the exhaust. The amount and timing of the mixing of the forced air with the exhaust can be determined by an electronic controller so that mixing air is provided in response to one or more predetermined operating conditions and/or anticipated operating conditions

An assembly and method for reducing nitrogen oxides, carbon monoxide, hydrocarbons and hydrogen gas in exhausts of internal combustion engines and simultaneously generating electrical power, wherein the exhaust is acted upon in a first stage catalytic converter and is at least in part passed through a thermoelectric generator for production of electrical power. The exhausts are thereafter directed to a second stage catalytic converter.

A device for use in a truck for lowering the temperature of exhaust gas of a combustion engine has a diffuser 1, which is provided with a cylindrical housing 3 provided with an inlet opening 5 in an end wall 7 and an elongated axially extending outlet opening 9 in the cylinder wall. The device furthermore has a bent guide plate 25 which extends from the outlet opening 9, so that, as a result of the Coanda effect, the hot exhaust gas is diverted along the plate and the jet widens, so that a better mixing with the ambient air, and hence greater cooling, takes place.

A turboprop engine assembly for an aircraft, including an internal combustion engine having a liquid coolant system, an air duct in fluid communication with an environment of the aircraft, a heat exchanger received within the air duct having coolant passages in fluid communication with the liquid coolant system and air passages air passages in fluid communication with the air duct, and an exhaust duct in fluid communication with an exhaust of the internal combustion engine. The exhaust duct has an outlet positioned within the air duct downstream of the heat exchanger and upstream of an outlet of the air duct, the outlet of the exhaust duct spaced inwardly from a peripheral wall of the air duct. In use, a flow of cooling air surrounds a flow of exhaust gases. A method of discharging air and exhaust gases in an turboprop engine assembly having an internal combustion engine is also discussed.