Patent ID: 8494679

Claim:
A method for dynamic control of a converter process during blowing of oxygen in steelmaking by way of exhaust gas analyses, with the aid of a process model with static process computation and with the aid of a submodel with dynamic process monitoring that is independent of the process model and that operates as a process monitor based on exhaust gas analysis, the method comprising the steps of: in a closed-loop control system that comprises a process monitoring and management unit with a measurement system, signal processing unit, the submodel as process monitor, and a process control or process management unit, as well as a process procedure with converter and process control or process operation; predicting oxygen content for blowing using the process model with static process computation; analyzing exhaust gas samples of the converter in the measurement system to determine analytical values of O 2 , CO, CO 2 and N 2 in the exhaust gas, using the submodel with dynamic process monitoring; obtaining signals representing said analytical values; processing said signals thus obtained, which correspond to the analytical values, in the signal processing unit; and then data correcting said process model with static process computation flow from the submodel into the process control or management unit for process control or process operation; wherein, with the aid of the submodel that is independent of the process model, the data correcting comprises: using a suitable combination of the constituent signals obtained, and computing values for critical decarburization time (t) and for an end of O 2 blowing (t′ EoB ); wherein the oxygen content predicted by the process model is corrected at a beginning of the process and adjusted to actual conditions towards an end of the decarburization period, where the critical decarburization time (t′ crit ) is expressed by: t=t′ crit if CP ( t )≧ CPP and CP ( t )=(N 2 )^n/(CO)^ m wherein CCP=predetermined limit parameter, CP=(N 2 )^n/(CO)^m for converters with a gap and low CO post-combustion, CP=(N 2 /CO 2 ) s for converters without a gap and high CO post-combustion, and the end of O 2 blowing (t′ EoB ) is expressed by: t=t′ EoB if EoB ( t )≧ EoBP 1 and EoB =(CO+CO 2 )− rPC wherein post-combustion in %=PC=CO 2 /(CO+CO 2 )100 and EoBP1=predetermined limit parameter, and the parameters in the equations for the critical decarburization time and for the end of O 2 blowing depend on the converter design and on the availability of gap adjustment and need to be adjusted at regular intervals.