SOUND ABSORBING ELEMENT WITH SOUND-REFLECTING LAYER Russian patent published in 2018 - IPC E04B1/84 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics. Sound absorbing element with the sound-reflecting layer comprises smooth and perforated surfaces, between which multilayer sound absorbing structure is located, at that, it is made in form of rigid and perforated walls, between which two layers are arranged: sound-reflecting layer adjoining rigid wall, and sound-absorbing layer, which adjoins the perforated wall, and as the sound-absorbing material used is mineral wool on basalt base of “Rockwool” type, or mineral wool of “URSA” type, or basalt wool of P-75 type, or glass wool with glass felt lining, or foamed polymer, for example, polyethylene or polypropylene, are used, at that, the fibrous sound absorbers surface is treated with special air permeable porous paints, (for example, “Acutex T”), or coated with the air-permeable fabrics or nonwoven materials, for example, “Lutrasil”, or as the sound-absorbing material the sound-absorbing porous material is used, for example, foam aluminum or cermet, or stone-shell limestone with the porosity degree within the range of optimal values: 30÷45 %, or metal foam, or material in the form of compacted crumbs from solid damping material, for example, elastomer, polyurethane or “Agat”, “Antivibrat”, “Schwim” types plasticate, wherein the crumb fractions size lies in the optimal range of values of 0.3…2.5 mm, and porous mineral single piece materials are also can be used, for example, pumice, vermiculite, kaolin, slags with cement or other binding, or synthetic fibers, at that, the fibrous sound absorbers surface is treated with special air permeable porous paints, or is covered with air permeable fabrics or non-woven materials.

EFFECT: increase in the sound attenuation efficiency and the structure reliability in general.

3 cl, 1 dwg