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

FIELD: machine engineering.

SUBSTANCE: in a low-noise ventilation system comprising a casing consisting of noise-absorbing frame panels with sound absorbing material in which a fan impeller is mounted fixed to a shaft passing through the casing rotating from a V-belt transmission by an electric motor also located on the frame, the casing being fixed with an input and the output of the square section of the branch pipe. Thereat a sound absorptive element is used as the sound-absorbing material of the cover panels, comprising a smooth and perforated surface between which a multi-layered sound absorbing structure is disposed which comprises 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 being formed by prismatic surfaces having a section parallel to the plane. The shape of the parallelogram, the internal surfaces of which have a dentate structure, or wavy, or a surface with spherical surfaces, the vertexes of the teeth facing inwardly of prismatic surfaces, with the edges of the prismatic surfaces fixed respectively on the smooth and perforated walls. 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, the inner surface of the perforated surface facing the sound-absorbing structure is lined with an acoustically transparent material.

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

3 dwg