| 摘要 |
FIELD: acoustics.SUBSTANCE: invention relates to means for reducing noise at industrial and transport facilities. Invention presupposes the following: in the custom-made hybrid-type sound absorber containing active- and reactive type acoustic absorbers located on a rigid frame consisting of two parts - the lower reactive part is made in the shape of a rigid hollow structure of cylindrical-conical shape, the upper active part is made in the shape of a rigid perforated cylindrical shell with perforated cover and solid base; at that, the cavity of the cylindrical shell is filled with sound absorbing material, and connection of the upper and lower parts is made by resilient damping element ensuring damping of high-frequency oscillations; the perforated cover of the perforated cylindrical shell has a pivotally mounted element with the help of which the frame is attached to the required object, for example the ceiling of the manufacturing facility; around the perforated cylindrical shell there is installed at least one screw sound absorbing element made in the form of a cylindrical coil spring. In the bottom, reactive part of the frame, the cylindrical part is hollow and has a shape of a Helmholtz reflection silencer with necks of different diameter, located in the cover and the base of the hollow cylinder, as well as on its side surface, while the cavity of the conical part represents a Helmholtz silencer with a neck located in the base of the cylinder.EFFECT: technical result: increase in efficiency of noise suppression at high frequencies by introduction into the sound absorber of cavities for Helmholtz silencers, which improve efficiency at high frequencies.3 cl, 1 dwg |
