| 摘要 |
A casting furnace is fed an inert gas under pressure through a feed line with the pressure being regulated by a melt level control device. When the pressure is reduced, the inert gas is exhausted from the casting furnace by an exhaust line, the feed line having a check valve to prevent gas which is contaminated by magnesium from entering the feed line. An oxidizing gas, preferably pressurized air, is periodically fed into the exhaust line by an oxidizing gas line for cleaning the drain line and the pressure-controlling aperture therein by oxidizing the magnesium. |
