A noise abatement system for internal combustion engines comprising: a containment body (12) equipped with an inlet hole (6) for the entry of exhaust gases from an internal combustion engine, a plurality of expansion chambers (10) placed in sequence and separated by parallel dividing partitions (13), each equipped with a through-hole (4) for the passage of gases placing in fluid communication two neighboring expansion chambers (10); said expansion chambers (10) having two opposing through-holes (4), one as gas inlet and one as gas outlet. A rotating shaft (9) is integrated in a rotating turbine (1), along an axis comprising the center of gravity of the expansion chambers (10) up to an opposite end of the containment body (12), said rotating shaft (9) having placed around said axis and on said shaft (9) rotary fins (3) which open and close the through-holes (4) between expansion chambers (10) alternately and generating a swirling movement of the flow of gas entering each expansion chamber (10).

A marine muffler includes a housing having a wet exhaust inlet, a water outlet, and a dry exhaust outlet. An internal chamber is divided by an angularly disposed baffle into lower and upper chambers. Vertical exhaust ducts penetrate the baffle and function to allow exhaust gas and entrained cooling water to pass from the lower chamber into the upper chamber. The second chamber is bounded at the top a second baffle which terminates the upward flow of exhaust thereby redirecting the exhaust downward. A pair of exhaust conduits extend through the second baffle thereby allowing exhaust to pass upward and into a third chamber which is bounded at it's uppermost portion by a third baffle defining a plurality of slotted apertures in fluid communication with the exhaust outlet. Water separated from the exhaust gas is directed to the water outlet by the diagonal baffle whereby it exits the housing.

A muffler for a vehicle includes: a muffler shell; a baffle disposed within the muffler shell, and having a first opening and a second opening which allow an exhaust gas to pass therethrough; and a variable valve mounted on the baffle. In particular, the variable valve includes: a valve plate rotatably mounted to open and close the first opening of the baffle; a valve arm connected to the valve plate; and a valve actuator to move the valve arm by variations in pressure of the exhaust gas. The valve plate is capable of rotating in a plane parallel to a plane of the baffle.

A noise suppressor is removably installed in power generator equipment including an enclosure and a power generator unit. The enclosure includes at least one of an air intake port and an air discharge port that are vents. The power generator unit is covered with the enclosure. The noise suppressor includes a tubular member having a first opening that opens to a direction different from the vent and a second opening that opens to the vent, forming a channel for gas leading from the first opening to the second opening, and provided with an acoustic liner inside the channel. The tubular member has such a shape that the channel bends at a plurality of points.

Methods and systems are provided for an exhaust muffler system with multiple inlets of different diameters. In one example, the muffler system may include multiple sets of inlet pipes to a muffler with each set of inlet pipes including pipes of different diameters with valves controlling exhaust flow into the inlet pipes. Exhaust from an engine bank may flow to a distinct set of inlet pipes and a distinct outlet pipe of the muffler via a separate exhaust passage.

A muffler includes a muffler housing having an exhaust gas inlet port adapted for securing to an exhaust pipe of an automobile so that exhaust gases from an internal combustion engine of the automobile are directed through the muffler housing from the exhaust gas inlet to an exhaust gas outlet. The muffler housing includes a plurality of rigid surfaces that form an exhaust gas pathway including a plurality of turns and lead from the exhaust gas inlet port to the exhaust gas outlet port. A photocatalyst coating is secured to an area of the rigid surfaces, and a light source is secured to the muffler housing and positioned to direct light onto the photocatalyst coating. The exhaust gases come into contact with the photocatalyst coating and reactive species generated by the photocatalyst coating decompose one or more pollutants in the exhaust gas.

The present application provides a muffler-heat exchanger (15) for an engine exhaust. The muffler-heat exchanger comprises a chamber (16) having an inlet (17) and an outlet (18) arranged such that during use exhaust gases flow through from the inlet to the outlet through the chamber. The muffler-heat exchanger also has at least one heat exchange baffle (25) disposed in the chamber to recover heat energy from the exhaust gases during use. The at least one heat exchange baffle is configured to reflect acoustic waves in the exhaust gases towards the inlet to generate destructive interference and impede incoming acoustic waves at the inlet. The present application also provides an exhaust system and an engine system.

A slip-type active noise control muffler reducing exhaust noise of a vehicle may include at least two guides connected to an inner wall of a housing accommodating exhaust gas in the muffler and formed in a pipe shape in a longitudinal direction of the muffler, and a baffle positioned in a plane shape partitioning the interior of the housing and including an electromagnet on the plane shape to control an interval of the baffles through a movement signal by current applied to the electromagnet according to frequency calculated from the exhaust gas, in which the interval of the baffles may be controlled and the exhaust noise may be reduced by controlling the number of wavelengths depending on the frequency.

A marine muffler capable of handling both marine engine exhaust gas and marine engine cooling water includes a double wall baffle partitioning the muffler interior so as to function as a cooling water conduit. The cooling water conduit includes an inlet disposed external to the main muffler housing and an outlet configured and disposed so as to discharge the engine cooling water into the exhaust duct connected to the muffler outlet. The muffler is thus able to convey the engine cooling water through the muffler housing within a dedicated conduit while maintaining the cooling water separate from the exhaust gas. A muffler that is adapted to handle both the exhaust and cooling water flowing from a marine engine allows for the elimination of engine cooling water piping.

Mufflers with unique configurations which, in certain (but not all) embodiments, improve engine performance. In other embodiments, improved manufacturing processes and methods for making mufflers. In particularly preferred embodiments, methods for making motorcycle mufflers with swaging techniques. In still other preferred embodiments, swaged motorcycle mufflers with improved exhaust flow. In still other embodiments, aftermarket mufflers which can be assembled to a variety of engine exhaust systems utilizing a universal coupler.