KOCHETOV SOUND ABSORBER FOR LINING MANUFACTURING FACILITIES Russian patent published in 2016 - IPC E04B1/84 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly to sound-absorbing devices for lining manufacturing facilities. It comprises a rigid and a perforated walls, between which there is a multilayer sound absorbing element. Device is made in the form of symmetric structures relative to the central vibration dampening layer. Each of the structures consists of five layers. Two layers adjacent to the walls are sound-absorbing layers from materials of different density. Three central layers are combined. Axial layer is sound-absorbing. Two symmetrical adjoining to it layers are made from a sound reflecting material of a complex profile. Latter consists of uniformly distributed hollow tetrahedrons, which enable to reflect sound waves incident in all directions. Each of the perforated walls has the following perforation parameters: hole diameter - 3÷7 mm, perforation percentage - 10 %÷15 %. As for the shape the holes can be circular, triangular, square, rectangular or diamond-shaped. In case of non-circular holes, it is necessary to consider as the nominal diameter the maximum diameter of the circle inscribed in the polygon. 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. Sound absorbing element over its entire surface is lined with an acoustically transparent material, for example, EZ-100 glass fabric or "poviden" type polymer.

EFFECT: higher efficiency of sound absorption and reliability of design overall.

4 cl, 1 dwg