A muffler for an exhaust system of an internal combustion engine includes at least one muffler component with a perforation defined by a plurality of through-flow openings in a wall of the muffler component. The through-flow openings can be flowed through in a flow direction in the direction from an upstream side of the wall to a downstream side of the wall. At least in the case of some or all of the through-flow openings of the perforation, a through-flow opening flow cross section decreases in the flow direction in order to provide a through-flow opening flow-guiding surface.

A muffler comprising a hollow cavity enclosed by a first bottom surface, a second bottom surface and a side wall, the side wall connects the first bottom surface with the second bottom surface, an air inlet at one end of the hollow cavity and an air outlet at the other end of the hollow cavity; the cavity is divided into a plurality of chambers in an axial direction, the chambers comprise a first chamber adjacent to the first bottom surface, a second chamber adjacent to the second bottom surface and an intermediate chamber located between the first chamber and the second chamber, the air inlet is in gas communication with the intermediate chamber, and the air outlet is in gas communication with the first chamber.

A lightweight and compact muffler device that can be installed in a limited space in an inside of a generator. A top cover and an undercover (end cover) provided on a top and a bottom of a vertically disposed casing are each formed in substantially trapezoidal shape. Thereby, an inner capacity of the casing can be secured to be large, as a result of which, a size of the muffler device can be made compact, and no extra component is required, so that reduction in manufacturing cost and reduction in weight can be achieved. Since the casing is disposed vertically, it is possible to install the casing even when an installation space is small in an inside of a housing of a generator, and it is possible to make the generator compact.

An exhaust muffler for an exhaust system of an internal combustion engine includes a muffler housing (12) with an outer shell (14) enclosing a muffler interior (22), through which exhaust gas can flow. An inner shell (54) is arranged in the muffler interior (22) and covers the outer shell (14) in at least some areas on an inner side (52) facing the muffler interior (22).

A two-stroke engine exhaust resonator with an exhaust gas catalytic converter comprising an inlet opening, wherein the inlet opening is followed by the first end of a stabilizing tube with a catalytic converter mounted thereon, characterized in that the other end of the stabilizing tube is directed towards the primary reflective surface, the primary reflective surface is followed by the first end of a resonator casing, which is surrounding the stabilizing tube, wherein the resonator casing exceeds at least over a part of the catalytic converter on the stabilizing tube, wherein a resonator outlet opening is arranged in the resonator casing between its first and second end or in the primary reflective surface, and at least a part of the resonator casing surrounding the stabilizing tube is surrounded by a cooler.

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 engine muffler apparatus for reducing noise and pollution from small gas engines such as those on landscaping tools includes an outer housing having a central neck extension with a principal aperture extending through to an outer housing cavity. The neck extension is selectively engageable with an exhaust of a small gas engine. The outer housing cavity has a plurality of vent apertures. An intake extension tube and a medial tube are coupled to the outer housing cavity. The medial tube has a medial cavity. A first filtering medium is coupled within the medial cavity and filters pollutants passing therethrough. A second filtering medium is coupled within the outer housing cavity outside of the medial tube and dampens sound waves passing through the apparatus from the exhaust.

An exhaust heat recovery system may include a muffler including a muffler case, a pipe through which exhaust gas flows, a baffle partitioning an internal space of the muffler case into a first space and a second space, and a valve mounted on an end portion of the pipe to change a direction in which the exhaust gas flows, and a heat exchanger mounted outside the muffler to fluidically-communicate with both the first and second spaces, allowing the exhaust gas to be introduced thereinto and to be discharged therefrom, the heat exchanger including a cooling channel through which cooling water flows, and heat exchange between the exhaust gas and the cooling water being performed in the heat exchanger.

A silencer for vacuum pumps which allows only for unidirectional flow and which reduces the noises caused by the air discharged at the exhaust of said pump. The silencer features baffles to divert and disrupt the flow and an umbrella check valve to ensure the unidirectionality of the discharge flow.

A vehicle having a frame and an internal combustion engine. An exhaust system extends from the internal combustion engine. The exhaust system includes an exhaust muffler with an exhaust hanger. The exhaust hanger is secured to the frame with an elastic member. An internal heat shield is located on an inner surface of the exhaust muffler to form an interior space between the internal heat shield and the exhaust muffler. The internal heat shield reduces the heat transferred to the elastic member.