This is an addn. to 857269, which describes a fume collector with a prim. duct and a sec. duct. The novelty in the present invention is that the prim. duct is connected by a valve to the lower part (a) of a switching chamber, whereas the sec. duct is connected to the upper part (b) of the chamber. Part (a) is connected to part (b) by a vertical pipe, which is surrounded by a ring-shaped water bath. In part (b) is a bell, which can be lowered into the water bath to prevent fumes in chamber (b) from entering zone (a). The result is that fumes from either the prim.- or the sec.- duct can be fed to the outlet of the switching chamber.
展开▼
