A muffler for receiving exhaust gas from a combustion engine comprises a shell, first and second inlet pipes each having outlets providing exhaust gas to a mixing chamber within the shell, a first chamber and a second chamber positioned within the shell and a pair of communication pipes each including an inlet receiving exhaust gas from the mixing chamber. Each communication pipe includes an outlet providing exhaust to the second chamber. Each of the communication pipes further includes a Helmholtz opening positioned downstream of the mixing chamber. The Helmholtz openings are open to the first chamber.

An acoustic damper includes a low porosity layer section and a housing. The low porosity layer section is formed in a liner of a gas turbine combustor and has an arrangement of elongated generally S-shaped slots formed therein. The housing has a plurality of feed apertures. The housing is coupled to the low porosity layer section thereby defining a cavity such that air outside the housing is configured to flow through the apertures and through the elongated generally S-shaped slots in the low porosity layer section, thereby transforming acoustic energy into thermal energy and aiding in providing an acoustic dampening effect for the gas turbine combustor during operation thereof.

A silencer for an exhaust gas system of an internal combustion engine includes a silencer housing which surrounds a silencer interior and which has at least two housing portions which are adjacent to each other in an abutment region. The two housing portions are connected to each other. The silencer housing has at least one housing opening formed therein and an outlet pipe extends through the silencer housing in the region of the housing opening. The housing opening is completely formed in one of the two housing portions.

An air exhausting device includes a muffler internally divided into a plurality of chambers by a separator, an inlet pipe that couples an exhaust pipe of an engine to the muffler, and an outlet pipe that is a path to discharge an exhaust gas inside the muffler to outside air. The muffler is configured of an expansion chamber to which a downstream end of the inlet pipe opens, and a resonator chamber communicated with only the expansion chamber via a plurality of resonator pipes. Any of or both of lengths and thicknesses of the plurality of resonator pipes are different.

A muffler for a vehicle includes: a case sealed at both ends by first and second side panels; first and second baffle plates installed in the case; a first chamber formed between the first side panel and the first baffle plate; a second chamber formed between the first baffle plate and the second baffle plate; a third chamber formed between the second baffle plate and the second side panel; an intake tube passing through the first side panel, and the first and second baffle plates, and including a first hole formed in a first body section located in the first chamber, and a second hole formed in a second body section located in the second chamber; and a pair of exhaust tubes passing through the first and second baffle plates, and the second side panel, and including a vent hole formed in body section located in the second chamber.

Disclosed is an exhaust-gas after-treatment device for an internal combustion engine, in particular for a ship's diesel internal combustion engine that is operated with heavy oil, including: a housing through which exhaust gas flows; exhaust-gas purification chambers formed in the housing, which chambers hold catalysts and/or particulate filters in order to purify the exhaust gas; and muffler chambers formed in the housing, which chambers have a defined depth for muffling sound in the flow direction. The exhaust-gas purification chambers and the muffler chambers are arranged spatially in series and parallel to one another on the flow side.

A combined exhaust gas noise silencer consisting of a system of hollow elements with a mutual housing comprising a front face of the silencer connected to the supply pipe of exhaust gases, and a rear face of the silencer with an outlet from the rear face of the silencer, where the original—inlet exhaust gas (İ.sub.p) carrying a noise wave is divided into at least two flows—an exhaust gas flow (İ.sub.z) carrying a shifted noise wave with delayed wave length, and an exhaust gas flow (İ.sub.n) carrying a non-shifted noise wave, which are subsequently combined into a common exhaust gas flow (İ.sub.s).

A muffler may include a shell, first and second baffles, an inlet pipe, first and second outlet pipes, and a communication pipe. The first and second baffles cooperate with the shell to define first, second and third chambers. The first inlet pipe may extend through the shell and may provide exhaust gas to at least one of the first and second chambers. Exhaust gas in the first chamber exits the muffler through the first outlet pipe. Exhaust gas in the second chamber exits the muffler through the second outlet pipe. The communication pipe may include first, second and third openings. The first opening is in communication with the first chamber. The second opening is in communication with the second chamber. The third opening is in communication with the third chamber. The first and second chambers may be in communication with the third chamber through the communication pipe.

Systems for and methods of evacuating air from a muffler while it is being filled with a fibrous material are disclosed.

An air exhausting device includes an inlet pipe that couples an exhaust pipe of an engine to a muffler, an outlet pipe that is a path to discharge an exhaust gas inside the muffler to outside air, and the muffler divided into a plurality of chambers by separators. The muffler is configured of a first expansion chamber, a second expansion chamber with which the outlet pipe is communicated, and a third expansion chamber. The inlet pipe is communicated with the first expansion chamber. The outlet pipe is communicated with the second expansion chamber. The first expansion chamber is adjacent to and communicated with the second expansion chamber via a first pipe. The second expansion chamber is communicated with the third expansion chamber via a second pipe. The first expansion chamber is communicated with the third expansion chamber via a third pipe.