KOCHSTAR-TYPE SINGLE-PIECE SOUND ABSORBER Russian patent published in 2016 - IPC E04B1/84 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to industrial acoustics, particularly, to broadband acoustic suppression. Sound absorber consists of perforated frame filled with sound absorbing material placed in protective shell. Frame is made in form of axially symmetric body of rotation of cylindrical shape with top and bottom flat bases. External toothed surface of said body has a toothed shape in the section perpendicular to the axis of the body of revolution. Inner surface is composed of cylindrical shell arranged coaxially with respect to cylindrical surface around which triangular teeth are located toothed surface. Cylindrical cavity inside the cylindrical shell is filled with sound reflecting material, for example foam aluminium, or metal-ceramics, or metal foam, or in form of compacted crumbs from solid damping material, for example, elastomer, polyurethane or elastrons of "Agat", "Antivibrat", "Schwim" types. Size of crumbs fractions is within optimal range of 0.3…2.5 mm. Inner cavity between cylindrical shell ring and external toothed surface is filled with sound absorbing material. Perforated framework has following perforation parameters: hole diameter 3÷7 mm, perforation percentage 10÷15 %. As for the shape the holes can be circular, triangular, square, rectangular or diamond-shaped. In case of non-circular holes, it is necessary to consider as the nominal diameter the maximum diameter of the circle inscribed in the polygon. As sound-absorbing material are used plates from mineral wool on basalt base “Rockwool" or "URSA" mineral wool or P-75 basalt wool or glass wool lined with glass felt, wherein sound absorbing element over its entire surface is lined with acoustically transparent material, for example, glass fabric EZ-100 or polymer of "Poviden" type, or as sound-absorbing material used sound sheet material, which is based on magnesite binder with reinforcing glass or glass, or polyester, or porous sound-absorbing ceramic material with volume density 500÷1,000 kg/m³ and consisting of 100 wt parts of pearlite with grain diameter of 0.1÷8.0 mm, 80÷250 wt parts of one of sintering materials selected from group comprising ash dust, slag, quartz, lava, stones or clay as main material, 5÷30 wt parts of inorganic binder, wherein after sintering mixture of pearlite particles form communicating holes between contact surfaces so that internal pores are interconnected.

EFFECT: invention allows to improve efficiency of noise suppression.

1 cl, 2 dwg