KOCHETOV'S LOW NOISE VENTILATION UNIT Russian patent published in 2017 - IPC F24F7/00 

FIELD: machine engineering.

SUBSTANCE: in the claimed ventilation unit, a sound-absorptive element is used as the sound-absorbing material of the shell panels, comprising a smooth and perforated surface between which is placed a multi-layer sound-absorbing structure that contains a smooth and perforated surface between which is a layer of sound-absorbing material of complex shape that is an alternation of solid areas and hollow sections. The hollow sections are formed by the prismatic surfaces having a form of a parallelogram in the section parallel to the drawing plane, the internal surfaces of which have a rack structure, or an undulating surface, or a surface with spherical surfaces. The teeth tops are directed inward the prismatic surfaces. The edges of the prismatic surfaces are fixed respectively on the perforated and smooth surfaces. Cavities of the hollow sections are filled with construction and installation foam, and the material of the perforated surface is made of solid, decorative damping materials, for example plastic "Aгat", "Aнtивибpиt", "Швим". The internal surface of perforated surface facing toward the sound absorbing structure is lined with an acoustically transparent material, such as fiberglass EG-100 or polymer "Пoвидeн", according to the invention a sound-absorptive element is used as the sound dampening shell panels material. The sound-absorptive element comprises a smooth, perforated surfaces, between which a multilayer sound absorbing design is placed, which is designed as a rigid and perforated walls, between which layers of sound-reflecting and sound-absorbing materials of different density disposed in two layers are located. Layers of the sound reflecting material are made with complex profile, out of uniformly distributed hollow tetrahedrons, ensuring reflection of sound waves incoming from all directions, and located responsively at rigid and perforated walls, and layers of the sound reflecting material are made out of heat insulating material able to maintain the specified microclimate in room, and as a sound absorbing material the soundproofing sheet material which is made based on magnesia astringent with a fiberglass or glass-fibre mat, or polyester, or a porous sound-absorbing ceramic material having a bulk density of 500÷1000 kg/m³, and consisting of 100 wt % of perlite with a grain diameter of 0.1÷8.0 mm, 80÷250 wt % of one of the sintering materials selected from the group consisting of fly ash, chark, quartz, lava, stones or clay as the main material, 5÷30 wt % of the inorganic binder is used. After sintering the mixture, perlite particles form communicating openings between their contacting surfaces so that the internal pores are in communication with each other.

EFFECT: increased efficiency of sound attenuation due to increase in sound absorption coefficient by increasing the sound absorption surfaces while maintaining the overall dimensions of the air handling unit.

5 dwg