WASTE GAS EXTRUDING APPARATUS

摘要

In a waste gas exhaust system for a vacuum process that uses halogen or halogen-compound gases e.g. in aluminium dry etching. The system includes a booster pump and an oil-sealed rotary pump as an auxiliary pump. The life of the rotary pump is extended by filling the exhaust side of the rotary pump with an inert gas (nitrogen) at a pressure above atmospheric. The exhaust gases from the rotary pump are absorbed in a dry absorption column. The lower vapour pressure components of the exhaust gases are trapped by a cooled dust trap between the booster pump and the auxiliary pump. The exhaust gases are heated between the two pumps.