| 摘要 |
PURPOSE:To decrease the burden of a person responsible for operations and to allow the operations to be stably executed by segmenting the evaluation of the in-furnace air permeability by a pressure drop to long-period rising air permeability and short-period rising air permeability, determining the boundary value and evaluating and monitoring the furnace condition fluctuation therefrom, thereby deciding the abnormality of the furnace conditions. CONSTITUTION:The air permeability evaluation by the pressure drop in the furnace is segmented to the long-period rising air permeability indicated by the average value of every specified time after raw materials are supplied before one round is made from past 30 minutes and the short-period rising air permeability indicated by the average value of every specified time below 30 minutes. The difference between the long period rising air permeability and the immediate near air permeability which is the judgment period is determined as the furnace condition fluctuation if the long-period rising air permeability and the difference between the above-mentioned short-period rising air permeability and the max. value of the immediate near air permeability is determined as the furnace condition fluctuation of the short-term air permeability. These differences are respectively evaluated by relative values and are monitored. The respective boundary values with the short time rise and long time rise in the respective periods of the decision on the abnormality of the furnace conditions are determined according to the levels of the fluctuations in the respective past air permeabilities. The abnormality of the furnace conditions are decided in accordance with these boundary values and the control to the blast furnace operations is started. |
