MULTI-SECTION SILENCER Russian patent published in 2018 - IPC F01N1/04 

FIELD: acoustics.

SUBSTANCE: invention relates to compressor stations and test boxes noise suppression equipment for gas turbine engines. Silencer incorporates cylindrical base, ejector, leveling grid on which sound-absorbing unit is fixed, consisting of sound-absorbing material layer lined from the inside with perforated shell, wherein the sound-absorbing unit consists of individual sequentially connected sections, in each section single sound absorbers are arranged in layers, and in the silencer upper part a screen type element is arranged, including a cylindrical shell, from the above connected to a cover, consisting of perforated layer and sound absorber, wherein exhaust openings are made in form of slits, made along shell periphery, and lined with the sound absorbing material, single sound absorbers are made in form of two regular polyhedrons concentric dimensional surfaces, wherein one of the surfaces: external, is made perforated, and other one: internal is made solid, and in gap between surfaces sound-absorbing element is arranged, at that, the surfaces are connected to each other by means of, at least, two bushings, which perform functions of Helmholtz resonator necks, formed by cavity inside the regular polyhedron solid surface, silencer sound-absorbing element is made in the form of three layers: central layer from the sound-reflecting material, of complex shape, consisting of uniformly distributed hollow tetrahedrons, allowing to reflect sound waves incident in all directions, and sound absorbing layers of different density materials symmetrically adjacent thereto, each of the perforated walls has the following perforation parameters: diameter of the holes is 3÷7 mm, perforation percentage is 10÷15%, wherein the holes can be made in form of circular, triangular, square, rectangular or rhomboid shape, wherein in case of non-circular holes, maximum diameter of circle inscribed into polygon shall be considered as nominal diameter, and plates from mineral wool on basalt base of “Rockwool” type are used as sound absorbing material, or from "URSA" mineral wool, or P-75 basalt wool, or glass wool with glass felt lining, wherein over its entire surface the sound absorbing element is lined with acoustically transparent material, for example, EZ-100 glass fabric or "poviden" type polymer.

EFFECT: technical result is increasing of noise absorption efficiency and structure reliability.

5 cl, 4 dwg