VENTILATION BOX OF THE SUBWAY Russian patent published in 2009 - IPC F24F13/24 E21F1/00 

FIELD: ventilation.

SUBSTANCE: box is designed for ventilation shaft of the subway. The box includes a headgear construction with air-conducting windows and external barrier in the form of ring-shaped shield. The shield is made in the form of cone widening upward and of amorphous material, and the inner surface of which is coated with a protective coating with sound reflecting inner surface. There is a through clearance between the shield and headgear construction.

EFFECT: sound reduction.

3 cl, 1 dwg