RING TYPE SOUND ABSORBING ELEMENT Russian patent published in 2018 - IPC E04B1/84 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics. Ring-type sound-absorbing element contains a smooth and perforated surface between which a multi-layered sound absorbing structure is placed. In the axial section, the sound-absorbing element is made in the form of a ring whose walls are made in the form of a rigid and perforated wall, between which there are two layers, one of which, adjacent to the rigid wall, is sound-absorbing, and the other, adjacent to the perforated wall, is made with a perforation from a sound-reflecting material of a complex profile consisting of uniformly distributed hollow tetrahedra. Material based on aluminum-containing alloys is used as the sound-reflecting material, followed by filling with titanium hydride or air with the density within 0.5…0.9 kg/m³ with the following strength properties: compressive strength within 5…10 MPa, bending strength within 10…20 MPa, for example foamed aluminum, or soundproofing plates based on a glass staple fiber of the type "Noisy" with a material density of 60÷80 kg/m³, or a magnesia binder based material with a reinforcing fiberglass or glass wool, and the perforated wall has the following perforation parameters: the diameter of the holes 3÷7 mm, perforation percentage 10÷15 %.

EFFECT: technical result consists in increased efficiency of acoustic suppression and of the reliability of the structure as a whole.

1 cl, 3 dwg