KOCHETOV(S ACOUSTIC SCREEN Russian patent published in 2016 - IPC E04B1/82 E01F8/00 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly, to broadband acoustic suppression, and can be used in all national economy industries as a means of protection from noise. Acoustic screen contains a frame with slants of metal sheets and located in it sections of acoustic panels, which are made both as noise reflecting and translucent, and opaque and noise absorbing. Their arrangement in the acoustic screen can be in any combination of vertical and horizontal rows. Each of opaque noise absorbing acoustic panels is made in form of perforated walls, between which there are layers of sound reflecting and sound-absorbing materials of different density arranged in two layers. Layers of sound reflecting material are made from complex profile composed of evenly distributed hollow tetrahedrons, allowing to reflect acoustical surges incident in all directions. Layers of sound-absorbing material are made from heat-insulating material able to maintain preset microclimate in room. Sound-absorbing material used is in the form of Rockwool mineral wool boards on a basalt base or URSA mineral wool or P-75 basalt wool or glass wool lined with glass felt. Sound absorbing element on its entire surface is lined with an acoustically transparent material, for example, EZ-100 glass cloth or Poviden polymer. Perforated wall has 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. Also sound-absorbing material opaque noise absorbing acoustic panels can be used porous noise absorbing material, for example foam aluminium or steel, or metallic foam, or material in form of compacted crumb from solid damping material, for example, polyurethane elastomer or elastrons "Agat", "Antivibrit", "Schwim", wherein size of fractions crumb is within optimal range of values: 0.3…2.5 mm, or in sound-absorbing material opaque noise absorbing acoustic panels used hard porous material, for example foam aluminium or steel, or stone-shell limestone with degree of porosity in range of optimal values: 30÷45 %.

EFFECT: invention allows to improve efficiency of noise suppression.

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