| 摘要 |
PURPOSE:To obtain a nozzle having a comparatively simple structure, excellent gas blow controllability, and a high keepability for the stability of a mushroom by using a specific structure of a double-structure blow nozzle attached to the bottom of a refining container for molten metal. CONSTITUTION:A gas blow nozzle 13 provided in a furnace bottom sheath 12 and a bottom refractory 5 is made up of a concentric double pipe consisting of an outer cylinder 14 and an inner cylinder 15, and the cylinder 15 is welded to the inner face of the clynider 14 through a thin plate holder 16. The lower end of the cylinder 15 is provided with a valve seat 17, forming an inner cylinder gas flow throttle valve structure with a valve 18 which is supported by a worm 20 through a rack lever 19 in a vertically movable manner. The worm 20 is operated by a drive lever 22 coupled with a handle 21. The lever 22 is connected rotatably to the inside of a sheath pipe 23 whose both ends are attached to the walls of the cylinder 14 across the cylinder 15. CO2 is supplied from a pipe 24 provided to fit to the through hole 25 of the bottom of the cylinder 14, directed in the directions of arrows 26-29, and injected into molten metal from the nozzle 13. |
