SOUND ABSORBING STRUCTURE Russian patent published in 2018 - IPC E04B1/82 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics and can be used for machine drive noise reduction, lining of manufacturing facilities and in other sound-absorbing structures. In the method, the sound-absorbing structure contains continuous and perforated surfaces between which a multi-layered sound-absorbing element is placed. Said multi-layered sound-absorbing element is made in the form of three layers: central layer from the sound-reflecting material, of complex shape, consisting of uniformly distributed hollow tetrahedrons, allowing to reflect sound waves incident in all directions, and symmetrically adjacent to it sound-absorbing layers of materials of different density. Each of perforated walls has following perforation parameters: diameter of holes – 3÷7 mm, perforation percentage – 10 %÷15 %. Said holes can have circular, triangular, square, rectangular or diamond-shaped profile. In case of non-circular holes, it is necessary to consider the maximum diameter of the circle inscribed in a polygon as the nominal diameter. As the sound-absorbing material, plates are used from Rockwool basalt-based mineral wool, or “URSA” mineral wool, or P-75 basalt wool, or glass wool lined with glass felt. And the sound absorbing element over its entire surface is lined with an acoustically transparent material, for example, EZ-100 glass fabric or “poviden” type polymer. In the central layer of the sound-reflecting material, consisting of uniformly distributed hollow tetrahedra, additional elements of sound absorption are located, they are made in the form of spherical surfaces filled with a sound absorber. Their diameter is chosen in such a way that it fits into the inner surface of the tetrahedron, so that its center coincides with the point of intersection of the heights on each of the three projections of the tetrahedron.

EFFECT: invention allows to improve efficiency of sound absorption and reliability of the structure on the whole.

1 cl, 1 dwg