時系列モデルによる連続製鋼プロセス用キュポラの操業管理

抄録

CSM Process is a continuous steelmaking process, developed to supersede electric furnace. In its demonstration plant, melting of scrap was carried out by a hot blast, liningless cupola to supply the steelmaking furnace with molten iron continuously for several days. The essentials of the cupola are to avoid bridging, which is caused by growth of skull at watercooled stack shell, and to keep the molten iron temperature T_M above a certain level. As a result of time series analysis with the records obtained during operation of the plant, following things were revealed.
(1) When the correlation of heat loss from stack shell H_S and windbox pressure P_B is neglegible while that of H_S and exhaust gas temperature T_E is appreciable, considerable melting should be taking place near the shell, and bridging is anticipated.
(2) As a function of blast temperature T_B and % coke C_R, the behavior of T_M can be expressed by a time series model, which is useful for forecasting as well as checking the stationarity. According to this model, 10°C rise of T_B should bring approximately 4°C increase in T_M without appreciable delay in average. Effect of C_R to T_M is estimated to be 515°C/% with 34 h delay.