VOLUMETRIC CONTROL FOR BLOWER FILTER DEVICES

The invention relates to a volumetric control for blower filter devices in which a control unit ( 5 ) determines a differential pressure between measuring points ( 1, 2 ) that is converted into a control signal for the fan output. To this end, at least two measuring points ( 1, 2 ) are arranged in the airflow behind the fan impeller ( 3 ) and in front of the consumer, in particular, the breathing hood ( 4 ). The measuring points ( 1, 2 ) can be located in the airflow inside the case filter device behind the impeller wheel ( 3 ) and in front of the outlet of the blower filter device or one measuring point is placed in the airflow inside the housing of the case filter device behind the impeller wheel ( 3 ) and one is placed in the vicinity of the connection of the breathing hood ( 4 ) or both measuring points are located in the breathing hose ( 8 ).