Fume evacuation duct with blower and retractable shutters, has shutters in pairs pivoted to inner surface of duct base and connected by hinges

摘要

The duct, designed to be installed e.g. in a tunnel or underground car park, or transported by an emergency vehicle, contains a blower system (2) and apertures in its base controlled by pairs of shutters (3). Each pair comprises front (5) and rear (7) shutters connected by a hinge and opened by a shuttle and slideway drive mechanism (13, 14, 17) connected to the front shutter and operated by a cable (20) and pulley (21) system. The rear shutter moves on rollers running in slideways along the sides of the aperture.