| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for controlling a nozzle, wherein an exchanging timing of the nozzle-like refractory can accurately be decided. SOLUTION: When the actually measured value measured by bringing a measuring element into contact with a control portion of a new nozzle-like refractory is set as an initial value P, a setting value until the thickness of the control portion comes to the reduced thickness limitation is denoted as Q, the minimum number of using until the nozzle-like refractory receives molten steel is denoted as R and the receiving number of the molten steel is denoted as n, the control value of the nozzle-like refractory at the time of being the n-th of the receiving number of the molten steel, is obtained from the following formula: the control value=P+n×[(Q-P)/R]. Then, after oxygen-washing, the control portion is measured with the measuring element at least one or more times of the maximum use number of times R, and in the case of exceeding the control value to the measured value, it is judged that the exchange of the nozzle-like refractory is necessary, and in the case of non-exceeding the control value, it is determined that this refractory can successively be used. COPYRIGHT: (C)2007,JPO&INPIT
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