DEVICE FOR ADJUSTING AIRFLOW RATE Russian patent published in 2013 - IPC F24F11/00 

FIELD: ventilation.

SUBSTANCE: device for adjusting airflow rate comprises a vertically disposed housing of the air duct with an end opening at the lower part and the valve mounted in it, the valve is made in the form of a leaf diaphragm, which leaves are mounted with its one end to the housing of the air duct with the ability to rotate about an axis of fastening, have two surfaces intersecting at angle to one another, the upper of which lies in a horizontal plane and is perforated. The valve comprises a mechanism of its return to the initial position, made in the form of a spring of temperature-sensitive material which changes its rigidity, which one end is fixed to the housing of the air duct and the second is fixed to the leaf of the diaphragm.

EFFECT: simplification of the device design, improvement of quality of adjusting airflow rate and extension of its field of application on existing exhaust shafts without changes in their design.