| 摘要 |
A refractory shutoff assembly for controlling the discharge of molten metal from a metallurgical vessel includes a refractory inner pipe to be fixedly mounted in a bottom of the vessel, such inner pipe having therethrough at least one opening at a position to be above the vessel bottom. A refractory outer pipe is mounted about the inner pipe and has therethrough at least one opening. The outer pipe has a lower end with an annular end surface. The outer pipe is movable relative to the inner pipe axially thereof between an open position, whereat the opening in the outer pipe aligns with the opening in the inner pipe, and a closed position, whereat such openings are isolated to block molten metal discharge. The length of possible axial movement of the outer pipe relative to the inner pipe from the open position is sufficient to enable movement of the outer pipe to another closed position, whereat the openings are isolated from each other and whereat the annular end surface sealingly abuts on an annular surface extending around the inner pipe, thereby entirely enclosing the inner pipe. |
