To reduce a pressure loss due to sticking of smoky dust to the inside of an exhaust duct of a vacuum refining furnace such as AOD, VOD or RH or a vessel and of a gas cooler.
An exhaust gas channel of a vacuum refining furnace 1 is provided with a bypass channel 6 in parallel with a gas cooler 3, and a water- cooled jacket 9 is so provided as to surround the tube body of the bypass channel 6, while an exhaust gas temperature gage 8 and an opening regulation damper are provided. Exhaust gas is passed through both of the gas cooler 3 and the bypass channel 6, while the temperature of the exhaust gas introduced into a dry type dust collector 4 is made the hear-resistance temperature of the collector 4 or below. According to this constitution, the quantity of the exhaust gas introduced into the gas cooler 3 can be lessened, while overheat of the dry type dust collector 4 is prevented. Therefore the amount of smoky dust sticking to the inside of an exhaust duct 2 and the gas cooler 3 is lessened and it is possible to reduce a pressure loss due to sticking of the smoky dust and to execute vacuum refining with excellent efficiency.
TANAKA TOMOAKI
SUMI MAKOTO
NITTETSU PLANT DESIGNING CORP