| 摘要 |
PROBLEM TO BE SOLVED: To effectively heat the inner part of a tundish by restraining and preventing oxygen from flowing into the tundish to be heated. SOLUTION: N2 being an inert gas is heated by being passed from either one of two heat regenerative preheaters 2A, 2B connected to the tundish 1 and charged into the tundish 1, and N2 is sucked from the other preheater, a heat reservoir is heated by combustion burners 5A, 5B, and the N2 is exhausted together with the combustion exhaust gas as the exhaust gas. At the time of heating the tundish 1 with convective heat transmission of the high temp. N2 by alternately repeating this operation, in order to restrain and prevent the flow-in of O2 contained in the combustion exhaust gas and the atmospheric air, even in the case of reducing the combustion exhaust gas when switching the charging/suction of N2 , the charging N2 flow rate is increased, the exhaust gas flow rate is reduced, or dilute gas flow rate is increased, for example, so that the suction N2 flow rate becomes less than the charging N2 flow rate by a prescribed value to maintain the positive pressure in the tundish 1. |
