A muffler includes a housing defining a first chamber, a second chamber and a third chamber. The muffler includes at least a pair of nested protrusions in communication with an inlet. The pair of nested protrusions is coupled to a respective surface of a pair of plates disposed in the housing such that one of the pair of nested protrusions is spaced apart from and opposite another of the pair of nested protrusions to define a tortuous path that terminates at an outlet defined along an outer circumference. The first chamber is downstream from the pair of plates. The muffler includes a first tube fluidly coupled to the first chamber to direct the exhaust gases from the first chamber to the second chamber. The muffler includes a second tube fluidly coupled to the second chamber to direct the exhaust gases from the second chamber to the third chamber.

An after treatment system (ATS) for a vehicle having an ATS module includes, fluidly connected in series, an inlet, a Diesel Oxidation Catalysts (DOC), a urea mixer and a Selective Catalytic Reduction (SCR), and an outlet. The inlet is fluidly connected to an output of an engine of the vehicle and the outlet is fluidly connected to an outlet tube of the vehicle. The inlet, DOC, mixer, SCR and outlet are arranged to define a substantial rectangular path of a flow (F) of exhaust gases flowing in the ATS, with the inlet and the outlet being positioned at a same vertex of the substantial rectangular path of the flow (F).

An exhaust apparatus includes a chamber disposed below an engine, an inlet pipe guiding exhaust gas from an exhaust pipe to the chamber, a tail pipe discharging the exhaust gas from the chamber to an outside, a first partition wall partitioning an inside of the chamber to a pair of left and right spaces, and a second partition wall partitioning one of the left and right spaces to a pair of front and rear spaces. Another of the left and right spaces is a first expansion chamber into which the inlet pipe enters. A rear space of the front and rear spaces is a second expansion chamber disposed downstream of the first expansion chamber. A front space of the front and rear spaces is a third expansion chamber disposed downstream of the second expansion chamber, and the tail pipe enters into the front space.

A mixer assembly unit, for an exhaust system exhaust gas treatment unit of an internal combustion engine, mixes exhaust gas discharged by the internal combustion engine with reactant. A mixing section (12), downstream in relation to a reactant release device (14), mixes exhaust gas, flowing in an exhaust gas flow direction, with reactant. The mixing section includes a core flow duct (34), extending in a direction of a mixing section longitudinal axis (L), through which a first exhaust gas partial stream (T1) flows. A second exhaust gas partial stream (T2) flows through a jacket flow duct (36) surrounding the core flow duct and separated from the core flow duct by an inner wall (30). The reactant release device releases reactant into the core flow duct or/and into the first exhaust gas partial stream. A mixer (38) is provided at an upstream end area (22) of the mixing section.

Provided is a muffler that can reduce sound pressure of a standing wave in an outlet pipe and, at the same time, can inhibit generation of flow noise. In one aspect of the present disclosure, the muffler includes a housing, an outlet pipe, a cover that covers the outlet pipe. The outlet pipe includes an outlet end and at least one communication hole. The outlet end opens into the housing. The at least one communication hole is formed in an outer circumferential surface of the outlet pipe. The cover includes a wall portion and an opening. The wall portion is disposed to overlap with the at least one communication hole in a radial direction of the outlet pipe. The opening communicates the at least one communication hole and an internal space of the housing with each other.

A compact Selective Catalytic Reduction (SCR) system comprising a system inlet, a gas flow system and a plurality of catalyst clusters is described. The system inlet is configured to utilize heat of the cleaned exhaust to vaporize a solution of a reductant, or a precursor of a reductant, and to mix the vaporized reductant with exhaust gas to form a mixed gas. The gas flow system is configured to provide the mixed gas from the system inlet to a plurality of catalyst clusters and to provide heat from the exhaust gas to assist in vaporization of the reductant/precursor and to assist in the conversion of the precursor to the reductant. The plurality of catalyst clusters comprise SCR and ASC catalysts but can also include filter functionality.

An exhaust system of a work machine is equipped with a first exhaust system, a second exhaust system, and a third exhaust system. The first exhaust system and the third exhaust system are arranged to be in parallel with respective one ends directed in the same direction. In a plan view, the second exhaust system is arranged with the other end side directed in the same direction as the one end sides of the first exhaust system and the third exhaust system to be in parallel with the first exhaust system and the third exhaust system between the first exhaust system and the third exhaust system and, in a side view, is arranged above the first exhaust system and the third exhaust system.

An exhaust treatment system for a work vehicle, which has an exhaust conduit transmitting an exhaust flow from an engine and to a DOC system, is disclosed. The DOC system has a reductant introduced and mixed into the exhaust flow, and a DOC conduit connects the DOC to a center inlet of an SCR. The SCR includes at least two exhaust chambers. When the exhaust flow enters the SCR at the center inlet, the exhaust flow enters a central chamber where it is split into at least two separate exhaust flows which are moved in at least two different directions away from each other. Each separate exhaust flow is moved through a separate exhaust chamber and substrate. A conduit moves at least one of the separate exhaust flows into an area holding another exhaust flow, and the two separate exhaust flows are combined and expelled through an outlet.

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.

Exhaust systems and passenger service vehicles, for example, buses are used together. The exhaust system can be arranged, in use, to be above an engine compartment. The exhaust system includes a first filter and a second filter, each filter having an inlet and an outlet. The inlets are inline with the respective first and second filters, and the outlets are transversely arranged with reference to the respective filters. Vehicles may have an overall length of about 35 feet or less and have an unladen weight of around 25,000 lbs or less.