KOCHETOV'S NOISE ABSORBING PANEL Russian patent published in 2014 - IPC E04B1/82 

FIELD: machine building.

SUBSTANCE: in noise absorbing panel, containing frame and noise absorbing insert located in its internal hollow, the frame is made as a parallelepiped formed by front and back walls. Noise absorbing insert is made as perforated plates, between which the symmetrically located layers of sound reflecting material are located, between which the layers of sound-absorbing materials of various density located in two layers. The layers of sound reflecting material are made from complex profile composed of evenly distributed hollow tetrahedrons, allowing to reflect acoustical surges incident in all directions. The layers are located at perforated plates.

EFFECT: improvement of efficiency of noise absorption at the expense of expansion of the frequent range.

4 cl, 2 dwg