Auxiliary ventilation device for an exhaust gas line of a fireplace and an exhaust gas line provided with such an auxiliary ventilation device, in particular an external exhaust gas line

摘要

The system (10) has a secondary air inlet pipe (12) that is provided with a secondary air inlet opening (22). The opening width of secondary air intake pipe is adjusted in dependence on difference between the pressures on opposite flap sides (28,30). An annular channel (42) is provided with a channel input (46) which is opened to outside environment of secondary air system. A throat (44) is provided between the channel input and channel output (48). The annular channel at the throat is connected with the air inlet chamber portion (34) through communication aperture (36).