ACOUSTIC ENCLOSURE Russian patent published in 2018 - IPC E04B1/82 G10K11/16 

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. Acoustic enclosure contains profiled and perforated walls, between which the sound-absorbing material layer is placed, wherein one of the walls is made smooth, and the sound-absorbing material is located in two layers, one of which, more rigid, is made solid and profiled, and the other, the soft one, is made discontinuous and located under the first layer surfaces, at that, the room sound-absorbing elements contain frame, window and door openings, openings for luminaires and acoustic enclosures, made in the form of rigid and perforated walls, between which arranged in two layers the sound-absorbing material is located, one of which, more rigid, is made of solid and profiled with complex profile consisting of inclined edges directed downwards and connected to the horizontal edges, and the other, the soft one, is made discontinuous and located under the first layer sound reflecting surfaces, wherein the sound absorbing material continuous profiled layer is made of a material, in which the sound reflection coefficient is greater than the sound absorption coefficient, and the discontinuous layer elements are made in the form of cone, polyhedral pyramid or figure of rotation formed by the n-th order curve, at that, the sound-absorbing element is 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, and as the sound absorbing material basalt based plates from mineral wool or porous noise-absorbing material are used. Acoustic enclosure 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, wherein layer of sound reflecting material is made with complex profile, and as a sound-absorbing material, a mineral wool on a basalt basis is used, or porous sound absorbing material, or the aluminum-containing alloys based material.

EFFECT: technical result is increase in the noise absorption efficiency due to the frequency range expansion and reflected from the sound absorber sound waves secondary absorption.

3 cl, 4 dwg