A low emissions 2-stroke natural gas fueled engine includes at least one cylinder with an exhaust port in communication with a silencer-catalytic converter unit. The unit has first and second volumes in communication with each other. The first volume damps spurious exhaust pressure excursions and removes particulates in the exhaust. The second volume houses an oxidation catalyst for treating exhaust to reduce exhaust emissions. The engine oil has at most 10 ppm zinc content to reduce metal poisons contained in the exhaust prior to contact with the oxidation catalyst. The engine oil preferably has a very low ash content to minimize sulfur combustion components in the exhaust to reduce masking of the oxidation catalyst. The first volume preferably has a pressure relief valve set to relieve at a pressure greater than the maximum normal operating pressure of the engine to avoid excessive pressure excursions of the engine exhaust from damaging the oxidation catalyst.

A silencer insert (10) for a silencer of an exhaust system includes a first and a second partition wall (11, 12) and a connecting wall (13) arranged therebetween. The first partition wall (11) defines a first plane (E1), the second partition wall (12) defines a second plane (E2), and the connecting wall (13) defines a third plane (E3). At least one of the first partition wall, the second partition wall, and the connecting wall includes at least one perforated area (15). The connecting wall (13) is formed in one piece with the first partition wall (11) and the second partition wall (12). The first plane encloses with the second plane an angle of not more than 60°, the first plane and the second plane being particularly in parallel. A silencer is provided including a housing (1) receiving the silencer insert (10). A method is provided for manufacturing the silencer insert.

A bulldozer includes a blade, an engine, first and second exhaust treatment devices that treat exhaust from the engine, and an engine cover. The first exhaust treatment device is disposed in front of the engine and lower than a first upper surface of the engine. The second exhaust treatment device is disposed above the engine. The engine cover includes a second upper surface sloping forward and downward. The engine cover covers the engine and the first and second exhaust treatment devices. Longitudinal directions of the first and second exhaust treatment devices extend along a vehicle lateral direction. In a top view of the bulldozer, the second exhaust treatment device includes a portion overlapping the engine. As seen from a side of the bulldozer, a front edge of the second exhaust treatment device is positioned forward of a rear edge of the first exhaust treatment device.

A engine device for a work vehicle, in which an engine, a first case, and a second case can be constituted in the same vibration structure, and exhaust gas path structure between the engine and the second case can be constituted in such a manner as to reduce costs. The engine device for a work vehicle according to the present invention of the instant application includes the first case for removing particulate matter in exhaust gas of the engine and the second case for removing nitrogen oxides in the exhaust gas of the engine, and configured to connect the first case to the second case via a urea mixing pipe. The engine, the first case, and the second case are integrally adhered, and the engine, the first case, and the second case are configured to be integrally vibrated in a swingable manner.

An exhaust muffler for transverse installation in a vehicle includes a muffler housing (26) elongated in the direction of a housing longitudinal axis (G) with a housing jacket (28) and two front walls (30, 32). The two front walls (30, 32) are arranged at spaced locations from one another and define an interior (34) of the muffler with the housing jacket (28). At least one inlet pipe (36) leads into the interior (34) of the muffler and at least one outlet pipe (20) leads out of the interior (34) of the muffler. At least one front wall (30, 32) has at least one predetermined deformation area (50, 52).

A reactor apparatus and method for removing and/or reducing NOx, CO, carbon particulates and hydrocarbons from exhaust gases produced by industrial processes includes a reactor including an inlet plenum, a reaction chamber, an outlet plenum, and a heat exchanger wherein gases exiting the reaction chamber heat gases entering the reaction chamber. EGR is drawn through a cooling heat exchanger with an injection blower and is delivered through control valves to the reaction chamber, the inlet plenum and to an add fuel mixing chamber whereby mixed fuel and EGR is delivered to the reaction chamber. A feedback controller controls the flow valves responsive to the temperatures in the reaction chamber entrance and the outlet plenum.

An exhaust duct assembly for conveying exhaust gases emanating from a combustion zone to atmosphere is disclosed. The assembly includes: an exhaust gas outlet for exhausting exhaust gas into the atmosphere; and an acoustic duct portion located upstream of the exhaust gas outlet, the acoustic duct portion having a peripheral wall defining a through-passage arranged and constructed to promote propagation of sound there-through. The acoustic duct portion has a length in a flow direction that is at least 50% of an average hydraulic diameter of the through-passage.

Systems and methods for reducing heat loss to a turbocharger during cold engine starting are described. In one example, a turbocharger bypass pipe and a turbocharger turbine pipe are oriented at forty five degrees relative to a longitudinal axis of a catalyst so that a turbocharger turbine may be completely bypassed, thereby increasing the amount of energy that may be transferred to the catalyst.

A water separator for use in a marine exhaust system comprises a horizontally disposed, generally cylindrical housing including a wet exhaust inlet, a dry exhaust outlet, and a water outlet. Wet exhaust entering the wet exhaust inlet is constrained against the inner housing wall by a variable geometry vane or baffle which causes the wet exhaust to accelerate such that centrifugal force causes the entrained water to separate from the exhaust gas. Separated water encounters a longitudinally disposed barrier and flows to the water outlet for discharge from the vessel. A tubular dry exhaust pipe is longitudinally disposed within the housing and includes an inlet disposed in proximity to a first end thereof, and an outlet projecting from a second end thereof.

An exhaust gas aftertreatment system for an internal combustion engine is disclosed. In one embodiment, the system has a first aftertreatment element including a first inlet region and a first outlet region, and a second aftertreatment element including a second inlet region and a second outlet region The first outlet region is connected to the second inlet region via at least one connection section, and the at least one connection section extends outside the first aftertreatment element. At least parts of the first inlet region and of the second inlet region are arranged in a common distributor housing.