SINGLE-PIECE VOLUMETRIC SOUND ABSORBER Russian patent published in 2018 - IPC E04B1/84 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly, to broadband noise suppression, and can be used in all branches of the national economy with sound attenuation of production equipment by sound absorption method. Volumetric single-piece sound absorber consists of a rigid frame suspended on the fastening element to thee production building ceiling, the frame is made in the form of Platonic solids regular polyhedrons two concentric solid surfaces, one of which, the external one, is made perforated, and the other, the internal one, is continuous, wherein the sound-absorbing material is wrapped in an acoustically transparent material, is located in the gap between the surfaces, the surfaces are connected together by, at least two resonant inserts having openings of different diameters, wherein the inner cavity, which is formed by the continuous inner volumetric surface is divided by at least, one partition into at least two resonance cavities, wherein at least one of which can be filled with sound absorbing material, and lamps with power supply are placed in the resonance inserts, wherein the perforation is made slotted, and as a sound absorbing material, basalt based plates from mineral wool, or mineral wool, or basalt wool, or glass wool with glass wool lining, or foamed polymer are used, and as an acoustically transparent material, for example glass fabric, or as a sound-absorbing material, elements of a rigid porous sound absorbing material are used, at that, the rigid frame walls sound-absorbing element is made in the form of a rigid and perforated walls, between which two layers are located: the adjacent to the rigid wall sound-reflecting layer, and adjacent to the perforated wall sound-absorbing layer, wherein the sound-reflecting material layer is made with a complex shape consisting of uniformly distributed hollow tetrahedra, allowing to reflect the incident in all directions sound waves, and the perforated wall has the following perforation parameters: hole diameter is 3÷7 mm, perforation percentage 10÷15 %, and as a sound-absorbing material, a basalt based mineral wool is used of the "Rockwool" type, or mineral wool of the "URSA" type, or basalt wool of P-75 type, or glass wool lined with glass felt, or foamed polymer, at that, the fibrous sound absorbers surface is treated with special air permeable porous paints, or is covered with air permeable fabrics or non-woven materials.

EFFECT: technical result of the invention is an increase in the noise attenuation efficiency by extending the frequency band and improving the operational properties.

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