SUSPENDED ACOUSTICAL CEILING Russian patent published in 2018 - IPC E04B1/84 E04B9/00 

FIELD: acoustics.

SUBSTANCE: invention relates to the industrial acoustics, particularly, to the broadband noise suppression, and can be used in all branches of the national economy in noise suppression of production equipment by sound absorption method. Acoustic suspended ceiling consists of rigid frame suspended to the production building ceiling with located inside the frame sound-absorbing structure made of sound-absorbing material wrapped in the acoustically transparent material. To the frame perforated sheet is attached. Frame is made in the form of rectangular parallelepiped with the sides dimensions in the plan view a×b, which ratio lies in the optimal range of values a:b=1:1…2:1, as well as the optimal sizes ratios c:d=0.1…0.5. Frame elements are attached to each other by means of brackets rigidly connected to rod, which are connected to suspensions. Perforated sheet has the following perforation parameters: perforation diameter is – 3…7 mm, perforation percentage is 10 %…15 %. In the frame lighting fixtures are installed. Sound-absorbing structure is made of at least one profiled porous sheet of sound-absorbing material bounded from above and from below by the perforated sheets, and in the cross-section the porous sheet profile can be triangular, rectangular, trapezoidal, sinusoidal. At that, the sound-absorbing structure is made in the form of rigid and perforated walls, between which two layers are arranged: adjoining the rigid wall sound-reflecting layer, and adjoining the perforated wall sound-absorbing layer. Sound-reflecting material layer is made of complex profile, consisting of uniformly distributed hollow tetrahedrons allowing to reflect the incident in all directions sound waves. By the shape, holes in perforated wall can be made in form of circular, triangular, square, rectangular or rhomboid profile holes, at that, in case of non-circular holes, as the conditional diameter the inscribed in the polygon circle maximum diameter should be considered. As the sound-absorbing material, basalt-based “Rockwool” type mineral wool is used, or "URSA" type mineral wool, or basalt wool of P-75 type, or glass wool with glass felt lining, or foamed polymer, for example, polyethylene or polypropylene, at that, the fibrous sound absorbers surface is treated with special air permeable porous paints, for example, “Acutex T”, or coated with air-permeable fabrics or nonwoven materials, for example, “Lutrasil”.

EFFECT: increase in the sound attenuation efficiency by increase in the sound absorption surface and the frequency range extension.

1 cl, 4 dwg