COMBINED-TYPE SOUND ABSORBER 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. Technical result is achieved by the fact that the composite sound absorber of the combined type contains sound absorbers of active and reactive types placed on a rigid frame, the frame is made of two parts, while the lower (reactive) part is made in the form of a rigid hollow cylinder-conical design, and the upper (active) part is made in the form of a rigid perforated cylindrical shell with a perforated cover and a solid base, the cavity of the cylindrical shell is filled with sound-absorbing material, and the connection of the upper and lower parts is made by means of an elastic damping element, the element is hinged to the perforated cover of the perforated cylindrical shell, and at least one screw sound-absorbing element is disposed around the perforated cylindrical shell, while in the cavity of the conical part of the reactive sound absorber cylinder-conical form, located on a rigid frame and representing a Helmholtz resonator with a neck located at the bottom of the hollow cylinder, there is an additional sound absorber, with a gap between the spherical surface of the additional sound absorber and the internal conical surface of the conical part of the reactive sound absorber, while the outer screw surface of the screw sound-absorbing element is perforated, and the spherical surface of the additional sound absorber is perforated, and the cavity of the additional sound absorber is filled with sound-absorbing material, while the density of the sound-absorbing material is less than the density of the screw sound-absorbing element.

EFFECT: technical result is an increase in the efficiency of noise attenuation at high frequencies by introducing into a unit acoustic absorber of cavities for Helmholtz resonators that increase efficiency at high frequencies.

1 cl, 1 dwg