RING TYPE SOUND ABSORBING ELEMENT Russian patent published in 2018 - IPC E04B1/84 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to the industrial acoustics. Ring-type sound-absorbing element contains a smooth and perforated surface, between which a multi-layer sound-absorbing structure is placed, in axial section, it is made in the form of a ring, the walls of which are made in the form of rigid and perforated walls. Perforated wall has the following perforation parameters: the diameter of the holes – 3÷7 mm, perforation percentage 10÷15 %. As for the shape the holes can be circular, triangular, square, rectangular or diamond-shaped. In case of non-circular holes, it is necessary to consider as the nominal diameter the maximum diameter of the circle inscribed in the polygon. Multi-layer sound-absorbing structure is an alternation of solid sections and hollow sections. Hollow areas are formed by prismatic surfaces having a parallelogram shape in cross section, the inner surfaces of which have a jagged structure. Tops of the teeth face inside the prismatic surfaces, and the edges of the prismatic surfaces are fixed respectively on the smooth and perforated walls. Cavities of the hollow sections, formed by prismatic surfaces, are filled with a sound absorber, and between the smooth surface and continuous sections of the layer of sound-absorbing material of complex shape, as well as between the perforated surface and solid sections, resonant plates with resonant inserts that perform the functions of the Helmholtz resonator necks are located.

EFFECT: technical result consists in increased efficiency of acoustic suppression and of the reliability of the structure as a whole.

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