SOUND-ABSORBING STRUCTURE OF INDUSTRIAL PREMISES Russian patent published in 2018 - IPC E04B1/82 F01N1/04 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly, to broadband noise suppression, and can be used in all branches of the national economy with sound attenuation of production equipment by sound absorption method. Production room sound-absorbing structure contains the workshop frame, window and door openings, openings for lighting fixtures, acoustic enclosures and sound absorbent elements. At that, the acoustic enclosures are made in the form of five layers, two of which, adjacent to the walls, are sound-absorbing layers from the different density materials, and three central layers are combined. Axial layer is sound-absorbing and the two symmetrical adjoining layers are made of sound-reflecting material with a complex profile, which consists of uniformly distributed hollow tetrahedrons, which enable to reflect sound waves incident in all directions. Each of perforated walls has following perforation parameters: holes diameter of 3÷7 mm, perforation percentage 10÷15 %, wherein by the form holes can be made in the form of round, triangular, square, rectangular or diamond-shaped profile holes. In case of non-circular holes, it is necessary to consider as nominal diameter maximum diameter of circle inscribed in polygon. 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-translucent material is sued to line said sound absorbing material over its entire surface. Perforated wall is made of structural materials with layer of soft vibration dampening material applied on their surfaces from one or two sides. As the sound-absorbing material the sound-absorbing porous material is used. Wherein the size of crumb fractions lies in the optimal range of values: 0.3…2.5 mm, and the porous mineral piece materials can also be used. Fibrous sound absorbers surface is treated with special air permeable porous paints, or is covered with air permeable fabrics or non-woven materials. As the sound-reflecting material, the aluminum-containing alloys based material is used, with subsequent filling with titanium hydride or air with a 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 or the glass staple fiber based soundproofing plates with material density of 60÷80 kg/m³.

EFFECT: improving the efficiency of noise reduction by expanding the frequency range and secondary absorption of sound waves reflected from the absorber.

1 cl, 4 dwg