RU2018136859A - PIECE SOUND ABSORBER - Google Patents

Claims (3)

1. A piece sound absorber, consisting of a perforated frame filled with sound-absorbing material placed in a protective shell, the frame is made of a rigid perforated outer cylindrical shell, which is connected to a rigid inner, coaxially located, cylindrical shell by rigid upper and lower flat bases. the cavity between the shells is filled with sound-absorbing material, for example rockwool-type basalt mineral wool, or URSA-type mineral wool, moreover, the sound-absorbing material over its entire surface is lined with an acoustically transparent material, for example, EZ-100 fiberglass or Poviden type polymer, while the cylindrical hollow rod is fixed to the base of the frame, inside it, axisymmetrically and coaxially to the inner cylindrical shell of the frame with the formation of a cavity, made of sound-reflecting material, the inner cavity of which is filled with sound-absorbing material, and attached to the rigid perforated outer cylindrical shell of the frame on the resonant part of the sound absorber, made in the form of at least two necks of the Helmholtz resonator, made in the form of cylindrical tubes rigidly connected to the outer cylindrical shell of the frame, and mounted perpendicular to its axis, while the cavity of the tubes are connected to a cavity formed by a rigid inner coaxially arranged, cylindrical shell, and the rod, and serving as the resonant cavity of the Helmholtz resonator, the volume of which is calculated at the required frequencies, the noise level at which it is necessary to reduce using the resonant part of the sound absorber, characterized in that the cylindrical hollow rod made of sound-reflecting material, the inner cavity of which is filled with sound-absorbing material, contains at least two resonance chambers interconnected by a resonant insert, which in turn is connected by a resonant an insert with a Helmholtz resonant cavity formed by the bases of the frame, its inner cylindrical shell and outer cylindrical shell a hollow rod made of sound-reflecting material, while the material based on foil, or fiberglass, or carbon fiber, or plastic containing carbon fibers as a reinforcing filler, and as a sound-absorbing material, which is filled with the internal cavity, is used as the sound-reflecting material of a cylindrical hollow rod rod, applied polyester, or porous fibrous or foamy sound-absorbing material, which is made on the basis of basalt or glass fibers, or open polyurethane foam with a protective sound-transparent sheath made of thin fiberglass or aluminized lavsan film. 2. The piece sound absorber according to claim 1, characterized in that a porous sound-absorbing ceramic material having a bulk density of 500 ÷ 1000 kg / m ³ and consisting of 100 mass parts of perlite with a particle diameter of 0.5 ÷ 2.0 is used as the sound-absorbing material. mm, 100 ÷ 200 mass parts of one or more sintering materials and 10 ÷ 20 mass parts of binder materials, or heat-resistant highly porous fibrous heat-insulating and sound-absorbing material made of mines was used as sound-absorbing material ral filler in the form of fibers of silicon dioxide, a binder, sintering agent, which is used as amorphous boron or boron nitride, and a surfactant, while silica fiber having a diameter of 4-10 μm is used as silicon dioxide fibers as a binder and at the same time, a surfactant used an aqueous solution of one of the substances selected from the group comprising methyl cellulose, carboxymethyl cellulose or carboxymethyl starch, the content of which is 2-5 wt. %, and additionally the material contains silica in the following ratio of components, wt. %: Silica fiber with a diameter of 4-10 microns 75.0-92.8 Amorphous boron or boron nitride 0.2-0.5 Silica sol 7.0-25.0