SINGLE-PIECE SOUND ABSORBER WITH HELICAL SOUND ABSORBING ELEMENTS Russian patent published in 2018 - IPC E04B1/84 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to means of reducing noise in industrial and transport facilities. Single piece sound absorber with helical sound-absorbing elements comprises active and reactive acoustic absorbers located on rigid frame, at that, the frame consists of two parts, at that, the lower, reactive part is made in the form of rigid, hollow cylinder, which bottom is connected to support disk connecting it to the support disk, on which the frame upper part is fixed through the resilient damping element, which is made in the form of rigid perforated cylindrical shell with perforated cover and connected to the support disk solid base, cylindrical shell cavity is filled with sound-absorbing material, and the upper and lower parts are connected by means of an elastic damping element, which allows to damp high-frequency oscillations, at that, to the perforated cylindrical shell perforated cover an element is hinged by means of which the frame is fixed to the desired object, for example, to the production room ceiling, and around the rigid perforated cylindrical shell at least one helical sound absorbing element is located, wherein the frame reactive portion cylinder cavity is hermetically sealed with the support disk with at least one opening serving as the Helmholtz resonator neck, which is formed together with the cylinder cavity, and around the hollow cylinder at least one helical sound-absorbing element is located, made in the form of cylindrical helical spring, enclosing the hollow cylinder and resting against the support discs, at that, as the sound absorbing material, the heat-resistant, highly porous fibrous heat-insulating and sound absorbing material made of mineral filler in the form of silica fibers, binder, sintering additive, which uses amorphous boron or boron nitride and surfactant, is used, at that, as the silica fibers, silicon fibers having diameter of 4–10 mcm are used, as the binder and simultaneously as the surfactant, aqueous solution one of the substances selected from the group consisting of methylcellulose, carboxymethylcellulose or carboxymethyl starch, which content is 2–5 wt.%, and the material additionally contains silica, is used.

EFFECT: increase the of noise attenuation efficiency at high frequencies by introduction of volumetric cavities for Helmholtz resonators into the single piece sound absorber, which increase efficiency at high frequencies.

1 cl, 1 dwg