KOCHETOV SINGLE-PIECE SOUND ABSORBER Russian patent published in 2018 - IPC F01N1/04 

FIELD: acoustics.

SUBSTANCE: invention relates to noise suppression equipment for compressor stations and test boxes for gas turbine engines. In the method, the sound absorber contains a cylindrical frame in the form of a perforated sleeve and caps, filled with a sound absorber, and outside the sleeve there is a layer of an acoustically transparent shell made of nylon mesh or glass fabric, and the frame comprises caps with annular beads for securing the cylindrical sleeve, while the caps are connected by a central rod with hooks at both ends, and the cylindrical bushing consists of two perforated shells, external and internal, space between which is filled with sound absorbing element. Said sound-absorbing material located in the internal cavity of the sound absorber is made of an unwinding roll, one end of which is rigidly fixed on the central rod, and the free end rests on the inner shell with the formation, in the section perpendicular to the rod, of a closed form in the form of an Archimedes spiral with air gaps increasing from the center to the periphery, while it has a higher porosity compared to the sound absorber located inside the shells, and the caps have cone-shaped fairings of their outer surfaces. Said sound-absorbing element is made in the form of external and internal perforated walls, between which a sound absorber is arranged consisting of three layers of sound-absorbing material, while the first layer, more rigid, is made solid and profiled and fixed on the outer surface, the second layer, softer than the first one, is made intermittent and located in the focus of the sound-reflecting surfaces of the first layer, and the third layer of the sound-absorbing element is made of foamed sound-absorbing material, for example, construction sealing foam, and is located between the first, more rigid layer and the perforated surface of the sound-absorbing element.

EFFECT: higher efficiency of soundproofing at low and medium frequencies.

1 cl, 4 dwg