An exhaust muffler has an outer cylinder into which an exhaust gas from an engine is introduced and a muffling member made of a foamed ceramic material. The outer cylinder has an inner cylinder through which the exhaust gas passes, a part of the muffling member is supported by an outer wall of the inner cylinder via a holding member. The inner cylinder includes, in an area where the inner cylinder overlaps with the muffling member with respect to axial direction of the inner cylinder, a porous wall portion formed with communication holes communicating an inside and an outside of the inner cylinder. The holding member is arranged at a position where it does not overlap with a part of the porous wall portion, so that muffling effect is enhanced, and the muffling member having a low resistance to impact forces can be supported stably by the inner cylinder.

Mixer box for mixing, vaporization and decomposition of a liquid additive to the exhaust gas flow from a combustion engine, comprising a gas inlet (108), a gas outlet (109) and internal duct means establishing a gas flow path (A-H, a-h) from the gas inlet (108) to the gas outlet (109). The duct means includes a first duct portion (107) having an outer wall (171) and an inner wall (161), which is surrounded by the outer wall (171), such that the gas flow path through said first duct portion (107) is established inbetween. The first duct portion (107) is provided with at least two partitions (121-124) extending between the outer wall (171) and the inner wall (161), which separate the first duct portion (107) into at least two duct sections (101a, 101b, 102a, 102b) of which at least one is an upstream duct section (101a, 101b) and at least one is a downstream duct section (102a, 102b).

An SCR system includes at least one catalyst, and an intake conduit. The intake conduit includes an intake conduit first sidewall, at least a portion of which defines a first curvature. An intake conduit second sidewall is coupled to the intake conduit first sidewall so as to define the intake conduit. A catalyst is fluidly coupled to the intake conduit through the intake conduit second sidewall. The intake conduit second sidewall is inclined at a first angle with respect to a longitudinal axis of the SCR system, such that an intake conduit second end cross-section of the intake conduit is smaller than an intake conduit first end cross-section. An intake conduit third sidewall is positioned at the intake conduit second end. The intake conduit is structured to produce an even flow split of the exhaust gas through the intake conduit internal volume towards the catalyst.

An after-treatment exhaust gas mixer for mixing the exhaust gas with a reducing agent, such as a diesel exhaust fluid for selective catalyst reduction, comprises a mixing chamber through which the exhaust gas circulates, from an inlet to an outlet, and a reducing agent sprayer, able to spray a reducing agent into the mixing chamber. The mixing chamber comprises a pipe that is rectilinear along an axis and the sprayer is positioned in the upstream part of the rectilinear pipe and oriented so as to spray in the downstream direction substantially parallel to the axis.

A multi-mode muffler for an exhaust system of an internal combustion engine provides a rotary plate that modulates exhaust gas flow between a first and second flow path. Each flow path may provide different sound dampening characteristics, thereby providing different sound profiles with the same muffler. In a disclosed embodiment, the rotary plate is driven by a shaft coupled to an external actuator. Also, a third possible position of the rotary plate may allow flow through both the first and second flow paths, thereby providing a third possible noise profile. One of the sound profiles may be louder than the other thereby allowing the muffler to switch between “loud” and “quiet” modes of operation.

An exhaust system noise reduction device of a vehicle enables an exhaust system to contribute to an increase in engine output while reducing engine exhaust noise. The exhaust system noise reduction device includes a muffler housing formed to airtightly surround a rear end section of an exhaust pipe; a branch pipe branched from a front end section of the exhaust pipe while having a rear end section of the branch pipe extend through the muffler housing; a barrier wall disposed at a peripheral surface of the rear end section of the exhaust pipe to divide an inner space of the muffler housing into a first chamber and a second chamber; and a punched portion formed at the rear end section of the branch pipe and disposed in the first chamber. A resonance chamber structure for reducing exhaust noise is formed in the first chamber, thereby reducing exhaust noise.

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.

An exhaust system is disclosed. A method of providing the exhaust system is also included. A vehicle may implement the exhaust system. In certain examples, the exhaust system includes a muffler having an exhaust inlet and an exhaust outlet. The exhaust system also includes a housing disposed around the muffler. The housing includes, in certain examples, a first exhaust opening disposed adjacent the exhaust outlet and configured to receive exhaust gasses from the exhaust outlet and direct the exhaust gasses away from the exhaust system in a normal operating mode, and a second exhaust opening configured to draw in ambient air in the normal operating mode.

A bilayler metamaterial silencer allows substantial fluid through the apparatus, while mitigating the propagation of sound through the apparatus, and while providing a form factor that is significantly more compact than previously-known devices. Moreover, illustrative embodiments allow a designer to specify one or both of the frequency or frequencies at which the apparatus mitigates sound propagation, and/or the bandwidth around the frequency or frequencies at which the apparatus mitigates sound propagation.

A canister assembly for use in an exhaust gas aftertreatment device comprises a cylindrical shell defining a cylindrical axis, a radial direction, and a circumferential direction, a top end and a bottom end. A flow tube is inserted into the top end of the cylindrical shell and terminates short of the bottom end of the cylindrical shell, defining an exit of the flow tube. A mixing bowl member including a symmetrical annular shape about the cylindrical axis and defining a mixing bowl pocket is attached at the bottom end of the cylindrical shell.