Patent ID: 8666557

Claim:
A method of charge material flow rate adjustment in a charging process of a shaft furnace, wherein: batches of charge material are discharged into said furnace from a top hopper using a flow control valve associated to said top hopper for controlling a flow rate of charge material fed to a distribution device for controlling the distribution of charge material inside the furnace, each batch representing a quantity of charge material that is stored intermediately in said top hopper in order to be discharged into the furnace; said method comprising: storing a respective set of plural valve settings for each batch, each valve setting of a set being associated to a different stage during the discharge of a respective batch from the respective top hopper, so that each different stage corresponds to a different operating status of said distribution device during the discharge of the respective batch; for a discharge of a given batch: at each stage in the discharge of said given batch: operating said flow control valve at a constant valve opening on the basis of the valve setting associated to said stage; determining an actual average flow rate at which charge material is discharged during said stage; and correcting each of said plural valve settings of the set stored for said given batch offline in function of the actual average flow rate determined for the associated stage.