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

FIELD: acoustics.

SUBSTANCE: invention relates to the industrial acoustics, particularly, to the broadband noise suppression, and can be used in all branches of the national economy during the production equipment noise suppression by the sound absorption method. Technical result is achieved due to fact, that the single-piece sound absorber consists of rigid frame suspended by hooks on cables to the production building ceiling, by the shape frame is made in the form of two perforated cubic congruent surfaces, external and internal, between which the sound-absorbing element is arranged, and in the interval between the external and internal surfaces at least two resonant inserts with holes of different diameters are located, which connect the external and internal surfaces to each other, and the inner cavity is divided by the partition into two resonant cavities, one of which is filled with sound-absorbing material, at that, the sound-absorbing element is made two-layered, wherein adjacent to one of the walls layer is made sound-absorbing, and adjacent to the other perforated wall, is made of a complex shaped sound-reflecting material, consisting of uniformly distributed hollow tetrahedrons, which allow to reflect sound waves incident in all directions, each of perforated walls has following perforation parameters: holes diameter 3÷7 mm, perforation percentage 10÷15 %, wherein by the form holes can be made in the form of round, triangular, square, rectangular or diamond-shaped profile holes, at that, in case of non-circular holes, as the conditional diameter the inscribed in the polygon circle maximum diameter should be considered, and as the sound-absorbing material layer the sound-absorbing porous material can be used, for example, foam aluminum, or cermet, or limestone rock with the porosity degree within the range of optimal values: 30÷45 %, or metal foam, or material in the form of compacted crumbs from solid damping material, for example, elastomer, polyurethane or “Agat”, “Antivibrat”, “Schwim” types plasticate, wherein the crumb fractions size lies in the optimal range of values of 0.3…2.5 mm, and porous mineral single piece materials are also can be used, for example, pumice, vermiculite, kaolin, slags with cement or other binding, or synthetic fibers, at that, the fibrous sound absorbers surface is treated with special air permeable porous paints, for example, “Acutex T” type, or coated with the air-permeable fabrics or nonwoven materials, for example, Lutrasil.

EFFECT: increase in the noise suppression efficiency due to the frequency band extension and the operational properties improvement.

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