SOUND-ABSORBING LINING Russian patent published in 2018 - IPC E04B1/84 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics. Technical result is achieved by the fact that the sound-absorbing lining is made in the form of a rigid and perforated walls, between which there is a multi-layer sound-absorbing element, the multi-layer sound-absorbing element is made in the form of two layers, one of which, adjacent to the rigid wall, is sound-absorbing, and the other, adjacent to the perforated wall, is made of a sound-reflecting material of a complex profile, consisting of uniformly distributed hollow tetrahedra, allowing to reflect the sound waves falling in all directions, as a sound-absorbing material, porous noise-absorbing material is used, for example, foam aluminum or cermet, or shell stone, or metal pore, or compacted crumb material of hard vibration damping materials, for example, elastomer, polyurethane, or plasticate, the size of the crumb fractions lying in the optimum range of values: 0.3…2.5 mm, and also porous mineral piece materials can be used, for example, pumice, vermiculite, kaolin, slags with cement or other cementing agent, or synthetic fibers, while the surface of fibrous absorbers is treated with special porous paints that let the air, or is covered with air-permeable fabrics or non-woven materials, and as a sound-reflecting material, a material based on aluminum-containing alloys is used, followed by filling with titanium hydride or air with a density within 0.5…0.9 kg/m³ with the following strength properties: compressive strength within 5…10 MPa, bending strength within 10…20 MPa, for example foam aluminum, or soundproofing plates based on a glass staple fiber of the type "Shumostop" with a material density of 60÷80 kg/m³, or as a sound-reflecting material, a magnesia binder-based material is used with a reinforcing fiberglass or glass-fibre mat, while the layer adjacent to the perforated wall is provided with a perforation of a sound-reflecting material, a complex profile consisting of uniformly distributed hollow tetrahedra, the perforation coefficient of the layer of the sound-reflecting material being made smaller than the perforation coefficient of the perforated wall of the sound-absorbing liner, and as a sound-reflecting material of the layer adjacent to the perforated wall, a foil-based material, or fiberglass, or carbon fibre reinforced plastic, or plastic, containing carbon fiber as a reinforcing filler, is used.

EFFECT: technical result is increase in the efficiency of acoustic suppression and reliability of the structure in general.

1 cl, 1 dwg