ACOUSTIC SCREEN Russian patent published in 2016 - IPC E04B1/84 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 the opaque noise absorbing acoustic panels is made as rigid and 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 have a complex profile consisting of evenly distributed hollow tetrahedrons, which allow to reflect sound waves coming in all directions, and which are located near rigid and perforated walls, respectively. Layers of sound reflecting material are made from heat-insulating material able to maintain preset microclimate in room. Sound-absorbing material is sound sheet material which is based on magnesite binder with reinforcing glass or glass canvas, or polyester, or porous sound-absorbing ceramic material with volume density of 500÷1,000 kg/m³ and consisting of 100 wt parts of Pearlite with grain diameter of 0.1÷8.0 mm, 80÷250 wt parts of one of sintering materials selected from a group comprising ash dust, slag, quartz, lava, stones or clay as main material, 5÷30 pts.wt inorganic binder. After sintering the mixture of Pearlite particles forms communicating holes between contact surfaces so that the inner pores are interconnected, and the perforated wall 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.

EFFECT: in case of non-round holes the nominal diameter should be considered the maximum diameter of circle inscribed in a polygon; higher efficiency of noise suppression.

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