摘要 |
In a charging process of a shaft furnace, in particular of a blast furnace, batches of charge material are typically discharged in cyclical sequence into the furnace from a top hopper using a flow control valve. A method and system is proposed for adjusting the flow rate of charge material in such a process. Pre-determined valve characteristics for certain types of material are provided, each indicating the relation between flow rate and valve setting for one type of material. According to the invention, a specific valve characteristic is stored for each batch of charge material, each specific valve characteristic being bijectively associated to one batch and indicating the relation between flow rate and valve setting of the flow control valve specifically for the associated batch. In relation to discharging a given batch of the sequence the invention proposes: using the stored specific valve characteristic associated to the given batch for determining a requested valve setting corresponding to a flow rate setpoint and using the requested valve setting to operate the flow control valve; determining an actual average flow rate for the discharge of the given batch; correcting the stored specific valve characteristic associated to the given batch in case of a stipulated deviation between the flow rate setpoint and the actual average flow rate. |