The dual function exhaust system attachment, which is preferably used with an all-terrain vehicle, includes a muffler, a silencing cap, and a sound-enhancing plug. In a quiet configuration, the silencing cap is mounted to conceal a primary outlet of the muffler. In a loud configuration, the sound-enhancing plug is mounted to conceal a secondary outlet of the muffler. A set of screw threads or sealing mechanism may be used to mount the silencing cap and the sound-enhancing plug. A primary perforated barrier, a solid barrier, at least one secondary perforated barrier, and a pipe section are positioned within a hollow structural body of the muffler to guide the exhaust gas flow from an inlet of the muffler to the primary outlet or the secondary outlet.

The present invention relates to an exhaust gas purification system comprising two catalytic sub-systems, wherein the first catalytic sub-system is for conversion of NOx, HC, CO and optionally particulate matter, and the second sub-system is for conversion of CO. The second sub-system locates at the downstream of the first catalytic sub-system. An air injection is positioned between the first catalytic sub-system and second catalytic sub-system.

An exhaust system includes an exhaust component with a wall having an outer surface and an inner surface that defines an internal exhaust gas flow path. At least one opening is formed in the exhaust component to extend through the wall of the exhaust component from the outer surface to the inner surface. A member is formed from a resistive material and is configured to cover the at least one opening. A diverter is positioned adjacent the at least one opening to block at least a portion of the exhaust gas flow path.

An exhaust purification system of an internal combustion engine comprises an HC adsorbent 20 arranged adsorbing HC in exhaust gas, an NOx adsorbent 20 adsorbing NOx in exhaust gas, a catalyst 24 removing HC and NOx at a predetermined air-fuel ratio, an air-fuel ratio control part 31 configured to control an air-fuel ratio of exhaust gas, and an HC concentration calculating part 32 configured to calculate a concentration of HC desorbed from the HC adsorbent. A peak of a desorption temperature of HC at the HC adsorbent and a peak of a desorption temperature of NOx at the NOx adsorbent are substantially the same. The air-fuel ratio control part is configured to control an air-fuel ratio of inflowing exhaust gas flowing into the catalyst to the predetermined air-fuel ratio based on the concentration of HC calculated by the HC concentration calculating part when HC is desorbed from the HC adsorbent.

Aspects of the present disclosure include a casing comprising an air inlet and an air outlet, a fan configured to move air from the air inlet to the air outlet, and a tunable sound attenuating module having an opening at a first end of the tunable sound attenuating module, a cavity, and a back wall at a second end of the tunable sound attenuating module, wherein: the tunable sound attenuating module is oriented such that the back wall is closer to the fan than the opening, and a length of tunable sound attenuating module is substantially one fourth of the acoustic wavelength of a sound generated by the fan.

An exhaust system is disclosed. A method of providing the exhaust system is also included. A vehicle may implement the exhaust system. In certain examples, the exhaust system includes a muffler having an exhaust inlet and an exhaust outlet. The exhaust system also includes a housing disposed around the muffler. The housing includes, in certain examples, a first exhaust opening disposed adjacent the exhaust outlet and configured to receive exhaust gasses from the exhaust outlet and direct the exhaust gasses away from the exhaust system in a normal operating mode, and a second exhaust opening configured to draw in ambient air in the normal operating mode.

An exhaust gas system is provided for a transport refrigeration unit (TRU) engine. The exhaust gas system includes an exhaust system. The exhaust system includes a catalyst operable in a temperature range to catalyze exhaust gas produced in the TRU engine and flown through the exhaust system. The exhaust gas system further includes temperature sensors respectively disposed to sense exhaust gas temperatures upstream of and downstream from the catalyst, at least one of first, second and third valves which are proportionally controllable to moderate amounts of air provided to the TRU engine, fuel provided to the TRU engine and air provided to the catalyst, respectively, and a controller. The controller is configured to compare sensed exhaust gas temperatures with the temperature range and issue a proportional signal to the at least one of the first, second and third valves in accordance with results of the comparison.

An internal combustion engine. Exhaust gas is flowable through an exhaust tract. Secondary air is flowable through a secondary air conduit and is introducible into the exhaust tract via the secondary air conduit. A mixture having secondary air introduced into the exhaust tract and fuel components is ignitable in the exhaust tract by an ignition device. Fresh air flowing through a suction tract is introducible into a combustion chamber via the suction tract. The secondary air conduit is fluidically connected to the suction tract at a diversion point where a portion of the fresh air in the suction tract is divertable from the suction tract by the secondary air conduit and is introducible into the exhaust tract as the secondary air. The fuel components that are contained in the exhaust gas, originate from the combustion chamber and reach the exhaust tract uncombusted from the combustion chamber.

An internal combustion engine. Exhaust gas is flowable through an exhaust tract. Secondary air is flowable through a secondary air conduit and is introducible into the exhaust tract via the secondary air conduit. A mixture having secondary air introduced into the exhaust tract and fuel components is ignitable in the exhaust tract by an ignition device. Fresh air flowing through a suction tract is introducible into a combustion chamber via the suction tract. The secondary air conduit is fluidically connected to the suction tract at a diversion point where a portion of the fresh air in the suction tract is divertable from the suction tract by the secondary air conduit and is introducible into the exhaust tract as the secondary air. The fuel components that are contained in the exhaust gas, originate from the combustion chamber and reach the exhaust tract uncombusted from the combustion chamber.

Method for producing thermal energy from a fuel containing hydrocarbons. According to the method, the fuel is burned in a combustion plant at an increased temperature, heat obtained from the combustion is recovered and the combustion's exhaust gases and soot particles are cleaned by catalytic exhaust-gas combustion. Fuel and air are fed to the invention's exhaust gases to form a gas mixture, which is brought to catalytic combustion performed at a temperature of more than 600 C. to reduce the nitrogen oxides and oxidize the carbon monoxide, hydrocarbons, and soot particles. The solution can be used to significantly reduce the level of the gas's NOx, and CO and VOC emissions. The thermal energy produced by the catalytic combustion process can also be used to produce heat, in which case the feed of fuel is divided between the combustion plant and the catalytic combustion process.