Abstract:
The heat exchanger of the purifier which draws heat from exhaust gases during the reaction sustained by the catalytic device comprises at least two parts. The first part (4) of the heat exchanger is intended to bring the temperature of the exhaust gases before entering the chamber (7) of the catalyst device down to the reaction temperature comprised between 270o and 500oC, which is the most favourable temperature in relation to the adopted process. After termination of the reaction sustained by the catalytic device, the exhaust gases go through an additional part (15) of the heat-exchanger.
Abstract:
The invention relates to a silencer being designed with sound absorptive material (13, 23) and a conduit section (1, 2) with one or more conduits (1) for leading gas flow into the silencer and with one or more outlets (2) for leading gas form the silencer. The sound absorptive material (13, 23) and the conduit section (1, 2) constitutes a protrusion extending from part of an outer shell (4) such as from an end cap (5, 6) constituting part of the shell for the silencer, or from an internal member, such as a baffle (9, 10) possibly separating at least two through-flowed chamber (12) of the silencer. Not-through-flowed cavities (17, 27) are arranged essentially adjacent to or at least partly surrounding said sound absorptive material (13, 23), thereby constituting one or more resonators acoustically communicating with said at least one through-flowed chamber. The silencer may also be designed so as to act as a spark-arrestor. Also, the invention relates to a combustion engine provided with such silencer.
Abstract:
A muffler for coupling to an exhaust port of an internal combustion engine. The muffler includes a housing having an exhaust inlet configured to receive exhaust gas from the engine, at least one internal expansion chamber and an outlet opening. The muffler further includes a diffuser cover attached to the housing over the exhaust opening of the housing forming an exhaust outlet of the muffler. The diffuser cover forms a trap chamber, a restricted throat and an ejector portion. The ejector portion is configured to draw in ambient air through an air inlet to cool the exhaust gas as it passes through the exhaust outlet. The restricted throat is positioned downstream from said trap chamber so as to increase the velocity of the exhaust gas as the exhaust gas passes through the restricted throat and into the ejector portion so as to aid in drawing in ambient air.
Abstract:
A high-performance muffler assembly (10) for exhaust system of an internal combustion engine. The muffler assembly comprises an elongated casing (20) having an inlet port (25) and an exit port (27) , a first pipe (34) disposed within the casing and having an inlet end (34a) in fluid communication with the inlet port and an outlet end (34b) selectively fluidly connected to the exit port of the casing, and a first valve (54) mounted within the casing. The first valve is selectively movable between a closed position and an open position for regulating an exhaust gas flow through the first pipe. The muffler assembly is operable in a number of different modes of operation including a high-performance mode, an exhaust braking mode, a reverse-flow mode, etc., determined by the positions of the first valve of the muffler assembly.
Abstract:
The exhaust sound and emission control system is a system for reducing sound and noxious emissions from an automotive exhaust. The system may have an exhaust resonator (34) having one or more catalytic converter elements (24) in combination therewith in a single device (10). Alternatively, the system may have multiple angularly disposed chambers therein, with a series of V-shaped baffles or guides in one of the chambers, thereby combining resonator and muffler functions in a single device. In another alternative, the system has a series of longitudinal tubes therein, in combination with a series of V-shaped guides or vanes, combining catalytic converter, muffler, and resonator functions in a single device. The various elements of the different embodiments, e.g. catalytic converter element(s), double wall shell, perforated tubes and multiple flow paths, interconnecting crossover tubes, etc., may be combined with one another as practicable.
Abstract:
A device (a silencer) for silencing a flow, comprises at least one acoustic chamber through-flowed by gas, e.g., exhaust gas, at least one inlet pipe and at least one pipe or passage interconnecting two chambers or a chamber and an exterior environment or chamber and is designed with such cross-sectional area transitions between passages and the chambers that sound attenuation achieved by the device is high while the pressure drop across the silencer is low and that high attenuation at low characteristic frequencies of flow systems comprising the device are obtained. One or more diffusers and/or monolithic bodies or catalysts may be comprised in the device. The passages may be curved or helical so as to allow for a low natural frequency. Embodiments with resonance chambers attenuating at selected frequencies are disclosed. A method for operating a vehicle comprising a combustion engine and a silencing system is disclosed. The engine may be a spark ignited combustion engine or a gas turbine engine, and the method may comprise controlling fuel injection, excess air ration and/or spark timing or adjusting vane guides in a turbine or a turbo charger.
Abstract:
A device (a silencer) for silencing a flow of gas, such as an exhaust gas, comprises at least one acoustic chamber (1, 2, 3) through-flowed by gas, at least one inlet pipe (6) for leading gas into the device and at least one pipe or passage (4, 12, 13) interconnecting two chambers or a chamber and an exterior environment or chamber and is designed with such features, including such cross-sectional area transitions between pipes or passages (4, 6, 12, 13) and the chambers (1, 2, 3) that the sound attenuation achieved by the device is high while the pressure drop across the silencer is low and that high attenuation at low characteristic frequencies of flow systems comprising the device are obtained. One or more diffusers (10a, 12a, 13a) for diffusing at least part of the gas flow, e.g., at the inlet to the chambers may be comprised in the device. One or more monolithic bodies or catalysers may be comprised in the device. Devices with curved or helical passages (Fig. 5) allowing a low natural frequency and embodiments having resonance chambers (Fig. 10a, b) attenuating at selected frequencies are disclosed. The device may be used for vehicles, including ships or boats and for stationary installations, such as power plants or stationary engines. A method for designing and/or dimensioning the device for a given desired sound attenuation over a given frequency spectrum at given spatial restrictions is disclosed.
Abstract:
A muffler (10) for coupling to an exhaust port of an internal combustion engine. The muffler (10) includes a housing (12) having an exhaust inlet (20) configured to receive exhaust gas from the engine, at least one internal expansion chamber (30) and an outlet opening (48). The muffler (10) further includes a diffuser cover (22) attached to the housing (12) over the exhaust opening (48) of the housing (12) forming an exhaust outlet of the muffler. The diffuser cover (22) forms a trap chamber (50), a restricted throat (60) and an ejector portion (52). The ejector portion (52) is configured to draw in ambient air through an air inlet (54) to cool the exhaust gas as it passes through the exhaust outlet (48). The restricted throat (60) is positioned downstream from said trap chamber (50) and has a smaller cross-sectional area than the trap chamber (50) so as to increase the velocity of the exhaust gas as the exhaust gas passes through the restricted throat (60) and into the ejector portion (52) so as to aid in drawing in ambient air.