Abstract: A silencer device for attenuating fluid borne noise has a flow through housing with an open upstream end for the entrance of a fluid into the housing and a coaxial open downstream end for exhausting the fluid from the housing. An entrance header formed of a plurality of spaced apart intersecting elongated members defining a plurality of rectangular entrance apertures, each elongated member having a V-shaped transverse cross-section shape and oriented with its apex pointed in an upstream direction, is coextensively disposed over the upstream open end. An exhaust header also formed of a plurality of spaced apart intersecting elongated members defining a plurality of rectangular exhaust apertures, each elongated member having a V-shaped transverse cross-section shape and oriented with its apex pointed in a downstream direction, is coextensively disposed over the downstream open end.

Abstract: A silencer for reducing the noise of an exhausting gas stream, comprising a hollow body having a connector, a sound-absorbing insert in the body and an inner component, the sound-absorbing insert comprising at least one split sheet of closed-pore foamed plastic material having a thickness of less than its average pore-size. Advantageously the sheet material comprises closed-pore cross-linked foamed polyethylene stacked or wound to provide about 3 to 30 layers, each layer ranging in thickness from about 0.1 to 1.0 mm, having an average pore diameter from about 0.2 to 2 mm and an air permeability from about 0.5 to 200 Rayl, the air permeability of the innermost layer ranging from about 1 to 4 times the air permeability of the outermost layer.