Patent ID: 8498320

Claim:
A melting furnace comprising: double walls having a first cooling passage therebetween; and a gas supplying unit configured to supply a gas to the melting furnace, the gas supplying unit comprising: a cooling passage pipe having a second cooling passage thereinside and protruding from a bottom to an inside of the melting furnace, an end of the cooling passage pipe connected only to an inner wall of the double walls such that a cooling liquid commutes between the first cooling passage and the second cooling passage, the cooling passage pipe having at least one opening in a side thereof; a gas supplying pipe penetrating the double walls having the first cooling passage and one end portion of the gas supplying pipe positioned inside the cooling passage pipe; and a nozzle pipe connected perpendicularly to the gas supplying pipe and having at least one nozzle hole formed at an end thereof, the nozzle hole leading to the opening in the side of the cooling passage pipe.