KOCHETOV(S NOISE ABSORBER WITH SOUND REFLECTING LAYER Russian patent published in 2016 - IPC E04B1/84 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics. This is achieved due to that a noise absorber with a reflecting layer comprises a smooth, perforated surface, sandwiching a multilayer sound absorbing structure, which is formed in two layers: a reflecting layer adjacent to a rigid wall and a sound absorbing layer adjacent to perforated wall, wherein layer of reflecting material has a complex profile, consisting of uniformly distributed hollow tetrahedrons, allowing to reflect sound waves incident in all directions, and perforated wall has following perforation parameters: hole diameter - 3÷7 mm, percentage of perforations 10 %÷15 %, wherein openings can be made in form of holes with a round, triangular, square, rectangular or diamond-shaped profile, where in case of non-circular hole, nominal size should be regarded as maximum diameter of circle inscribed said polygon, and sound absorbing material used is mineral wool based on basalt of type “Rockwool”, or mineral wool of type “URSA” or basalt wool type P-75, or glass fibre lined with glass felt or a foamed polymer, such as polyethylene or polypropylene, surface of fibrous absorbers is treated with special air-permeable porous paints (for example, “Acutex T”) or is covered with air-permeable woven or nonwoven materials, for example “Lutrasilom”.

EFFECT: technical result is high efficiency of noise absorption and reliability of structure overall.

1 cl, 1 dwg