NOISE SUPPRESSOR Russian patent published in 2018 - IPC F01N1/24 

FIELD: acoustics.

SUBSTANCE: noise silencer comprises a cylindrical base which is rigidly connected to the end inlet and outlet nozzles rigidly connected to the central partitions having perforations. On the basement there is an aligning grid connected to the adapter, on which the sound-absorbing unit consisting of separate series-connected sections is fixed. Each of the sections is made of a layer of sound-absorbing material with a thickness "a", lined inside with a perforated cover. Section consists of four subsections, in which there are single sound absorbers with the characteristic size "c". Sound-absorbing lining is made in the form of two outer perforated walls and an inner, middle wall, made in the form of a membrane resonant plate, between which are layers of sound absorbing material. Middle wall divides the lining into two congruent parts, each of which has three layers of sound-absorbing material. More rigid first layers are made solid, profiled and fixed respectively on external perforated walls. Second layers, softer than the first, are intermittent and are located with a gap in the focus of the reflective surfaces of the first layers. Latter have the form of bodies of revolution in the form of cones connected by bases, and the first layers are made of a material with a reflection coefficient of sound greater than its sound absorption coefficient, in the form of profiles of conical surfaces that focus the reflected sound on the second layers. Third sound absorbing layers are made of foamed sound-absorbing material in the form of a construction sealing foam and are located in the gaps and voids, which are formed between the first and the second layers.

EFFECT: noise silencer is proposed.

4 cl, 3 dwg