A sound suppression apparatus for installation inside a gas transport duct is provided. The sound suppression apparatus comprises a resistive sound-absorbing element (110) and a housing providing a reactive sound-attenuating element (130) communicating with a surrounding of the apparatus via opening in an outer surface of the housing. An outer surface of the sound suppression apparatus comprises an outer surface of the resistive sound-absorbing element and the outer surface of the housing. A gas transport duct comprising the sound suppression apparatus is also provided.

An engine exhaust system includes an exhaust pipe assembly having an engine exhaust system inlet configured to receive engine exhaust and an engine exhaust system outlet. The system includes a first selective catalytic reduction (SCR) catalyst device positioned downstream in exhaust flow from the engine exhaust system inlet. The first SCR catalyst device includes a substrate with a metallic catalyst coated on the substrate. An electric heater is configured to heat the metallic catalyst. A second SCR catalyst device is positioned downstream in engine exhaust flow from the first SCR catalyst device and upstream of the engine exhaust system outlet. The first SCR catalyst device and the exhaust pipe assembly define an empty chamber between the substrate and the second SCR catalyst device. Engine exhaust flows directly from the substrate to the second SCR catalyst device through the empty chamber.

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 device for the aftertreatment of exhaust gases of an internal combustion engine, having at least one catalytic converter, through which exhaust gas can flow, and at least one muffler formed by a closed volume and through which exhaust gas can flow along an inflow section to an outflow section. The catalytic converter is formed by a honeycomb body that has a plurality of flow channels through which exhaust gas can flow. The honeycomb body is accommodated in a casing tube, which surrounds the honeycomb body, and is connected to the casing tube in a materially bonded manner. The catalytic converter is arranged in the interior of the muffler.

A muffler includes an inner pipe and an outer pipe which, along with the inner pipe, forms a double-wall pipe. A cavity is provided between the inner and outer pipes. A first end of the double-wall pipe is closed between the inner and outer pipes, and a second end of the double-wall pipe has an opening between the inner and outer pipes. The cavity communicates with an exhaust channel via the opening. The cavity is formed as a result of the inner pipe being shaped in a manner such that a portion of an outer-circumferential surface of the inner pipe is positioned on an inner-circumferential side relative to a reference, the reference being a position of an outer-circumferential surface of the outer pipe.

A device for the aftertreatment of exhaust gases of an internal combustion engine, having at least one catalytic converter, through which exhaust gas can flow, and at least one muffler formed by a closed volume and through which exhaust gas can flow along an inflow section to an outflow section. The catalytic converter is formed by a honeycomb body that has a plurality of flow channels through which exhaust gas can flow. The honeycomb body is accommodated in a casing tube, which surrounds the honeycomb body, and is connected to the casing tube in a materially bonded manner. The catalytic converter is arranged in the interior of the muffler.

In order to further improve the sound damping in a refrigerant compressor comprising a common housing, a screw-type compressor in a common housing has a compressor housing that is formed as part of the common housing with a first sound absorber unit which is arranged in the common housing. The first sound absorber unit is arranged adjacent a housing window, and the sound absorber unit comprises at least one chamber which is located between an inlet opening and an outlet opening and which widens out relative to the inlet opening and to the outlet opening in a direction transverse to a direction of flow.

A sound suppression apparatus for installation inside a gas transport duct is provided. The sound suppression apparatus comprises a resistive sound-absorbing element (110) and a housing providing a reactive sound-attenuating element (130) communicating with a surrounding of the apparatus via opening in an outer surface of the housing. An outer surface of the sound suppression apparatus comprises an outer surface of the resistive sound-absorbing element and the outer surface of the housing. A gas transport duct comprising the sound suppression apparatus is also provided.

An embodiment of an exhaust handling system for a marine vessel includes a cap connected to a top end portion of an exhaust stack of the marine vessel to form an enclosure at least partially surrounding an outlet of an exhaust pipe extending through the exhaust stack. In addition, the exhaust handling system includes a collection pipe in fluid communication with the cap such that the collection pipe is to receive exhaust from the enclosure, and a coupling connected to the collection pipe that is to connect to an exhaust cleaning assembly. The exhaust cleaning system includes a tank to receive the exhaust. The cap at least partially defines a first flow path for the exhaust that extends from the enclosure to the atmosphere. The collection pipe at least partially defines a second flow path for the exhaust that extends from the enclosure to the coupling via the collection pipe.

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 originalinlet exhaust gas (?.sub.p) carrying a noise wave is divided into at least two flowsan exhaust gas flow (?.sub.z) carrying a shifted noise wave with delayed wave length, and an exhaust gas flow (?.sub.n) carrying a non-shifted noise wave, which are subsequently combined into a common exhaust gas flow (?.sub.s).