| 摘要 |
PURPOSE:To maintain the flow rates of the supply gases in the inside and outside pipes of the tuyere of a converter by throttling the gases to be supplied to the inside and outside pipes on generation of a switching command, flowing the supply gases to be switched to the respective pipes and controlling the flow rate thereof then stopping the supply of the above-described preceding gases. CONSTITUTION:The supply of gases from the 1st pipeline to the 2nd pipeline for an inside pipe 7 and from the 3rd pipeline to the 4th pipeline for an outside pipe 6 is changed over respectively among the 1st and the 2nd pipelines communicating with the inside pipe 7 of the above-described tuyere 8 and the 3rd and the 4th pipelines communicating with the outside pipe 6. The shut-off valves 4D, 4B of the 2nd and the 4th pipelines are opened to start flowing of the 2nd and the 4th gases D, B respectively upon incoming of a switching command. When the opening of the valves 4D, 4B is finished, the set values for controlling the respective flow rates of the 1st and the 3rd gases C, A in the 1st and the 3rd pipelines are stepped down simultaneously. If there is no abnormality after a specified time, the valves 4C, 4D in the 1st and the 3rd pipelines are closed and the automatic control for controlling the respective flow rates of the gases D, B for the 2nd and the 4th pipelines is started and the switching of the gases is completed. |
