A unitary, skid-type sound attenuator assembly for simultaneously managing sound from multiple sources. The assembly may include a dedicated muffler for each sound source. In turn, each of these mufflers includes an outlet for directing sound toward a location such as between the various mufflers of the assembly so as to provide an added level of noise cancellation. Additionally, the assembly may include an attenuator at such a common central location for further noise reduction. The attenuator may also serve a filtering function, for example where the sound sources are engines and the assembly is utilized for managing exhaust therefrom such as in an oilfield environment.

A particle filter (2) for filtering exhaust gas in an internal combustion engine includes a housing and a filter element. A simplified installation and/or simplified replacement of the filter element (5) and/or improved sealing of the housing (4) results if the filter element (5) is supported in an inner jacket (9), which is supported radially in an outer jacket (12) and is arranged so as to be axially movable in the outer jacket (12). The inner jacket (9) is axially supported on a ring (24), which is supported axially on a cover (22) that closes an installation opening (20) of the housing (4) via at least one supporting element (25) in order to transmit pressure forces. A muffler (1) is provided having such a particle filter (2), wherein a section of a muffler housing (3) of the muffler (1) forms the housing (4) of the particle filter (2).

The present invention relates to a catalyst comprising two layers on an inert catalyst carrier. Layer A contains at least palladium as a platinum group metal, alumina, and a first cerium/zirconium/lanthanum/yttrium mixed oxide. A layer B applied to layer A contains at least rhodium as a platinum group metal, alumina, and a second cerium/zirconium/lanthanum/yttrium mixed oxide.