ACOUSTIC DEVICE Russian patent published in 2016 - IPC E04B1/84 G10K11/16 

FIELD: acoustics.

SUBSTANCE: invention relates to an industrial acoustics, particularly broadband and low frequency sound insulation, and can be used in all industries when noise-proofing production equipment by sound absorption. Acoustic device consists of at least two sound-absorbing sections, each of which comprises walls made of corrugated perforated material, between which there are sound-absorbing elements. Walls of corrugated material are provided with slotted perforation made of stainless steel or a galvanized steel sheet 0.7 mm thick with a polymer protective and decorative coating such as "Pural" 50 mcm thick or "Polyester" 25 mcm thick, or of an aluminium sheet 1.0 mm thick and coating 25 mcm thick. Sound absorbing sections are suspended on ropes by hooks. Each of sound-absorbing elements is in form of perforated plates between which layers are arranged symmetrically with a reflecting material, and in centre of reflecting material between layers of sound-absorbing materials are layers of different density disposed in two layers. Layers of sound reflecting material are made from complex profile composed of evenly distributed hollow tetrahedrons, allowing for reflection of acoustic waves incident in all directions, and being installed respectively at perforated plates. Perforated plate can be made of plastic, for instance, caprone, or metal mesh with small cells. Sound-absorbing material used is porous sound-absorbing ceramic material with volume density 500÷1000 kg/m³ and consisting of 100 parts by weight of pearlite with particle diameter of 0.5÷2.0 mm, 100÷200 parts by weight of one or several sintering materials and 10÷20 weight parts of binding materials or plate from mineral wool on basalt base Rockwool or URSA mineral wool, or P-75 basalt wool or glass wool lined with glass felt, sound absorbing element over its entire surface is lined with acoustically transparent material, for example, glass fabric EZ-100 or "poviden" polymer, or hard porous noise absorbing material, for example ceramic metal, or stone-shell limestone with degree of porosity in range of optimal values: 30…45 %, or from solid crumbs of vibration-damping material such as an elastomer, plastic or polyurethane type "Agat" "Antivibrit" "Shvim", and crumb fraction size lies in optimal range of values: 0.3…2.5 mm.

EFFECT: invention improves acoustic characteristics at low, medium and high frequencies with provision of dust repulsion.

3 cl, 2 dwg