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, 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, and around the rigid perforated cylindrical shell at least one helical sound absorbing element is located, at that, the perforated surfaces have the following perforation parameters: holes diameter – 3÷7 mm, perforation percentage 10 % ÷ 15 %, and holes in perforated surfaces can be made in form of circular, triangular, square, rectangular or rhomboid shaped holes, at that, ratio between the material and the vibration damping coating thicknesses lies in the optimum range of values: 1/(2.5…3.5), or from stainless steel, or galvanized sheet with the thickness of 0.7 mm with the “Pural” type polymeric protective-decorative coating with thickness of 50 mcm, or “Polyester” type with thickness of 25 mcm, or aluminum sheet with thickness of 1.0 mm and coating thickness of 25 mcm, or from hard decorative vibration damping materials.

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