Monitoring and control of pig iron refining

Claim 1

A METHOD OF MONITORING AND CONTROLLING A PIG IRON REFINING OPERATION IN WHICH AN OXYGEN-CONTAINING GAS IS BLOWN FROM ABOVE BY MEANS OF A LANCE ONTO A BATH OF MOLTEN PIG IRON IN A VESSEL, REFINING AGENTS ARE FED INTO THE VESSEL, AND THE GASES LEAVING THE VESSEL ARE WITHDRAWN THROUGH A HOOD; THE REFINING OPERATION TAKING PLACE UNDER REGULABLE REFINING CONDITIONS COMPRISING THE HEIGHT OF THE LANCE ABOVE THE BATH, THE RATE OF FLOW OF GAS THROUGH THE LANCE, AND THE RATE AT WHICH REFINING AGENTS ARE FED IN; THE METHOD COMPRISING THE STEPS OF I. AUTOMATICALLY DETERMINING THE MEANS SPEED OF SAID GASES AT A GIVEN POSITION IN THE HOOD AT WHICH THE CO IN SAID GASES HAS BURNT TO CO2 AND PRIOR TO DUST REMOVAL OR DRYING OF SAID GASES, BY A AUTOMATICALLY MEASURING THE TIME TAKEN BY AN ACOUSTIC WAVE TO TRAVEL THROUGH SAID GASES FROM AN EMITTER TO A RECEIVER UPSTREAM OF THE EMITTER, B. AUTOMATICALLY MEASURING THE TIME TAKEN BY AN ACOUSTIC WAVE TO TRAVEL THROUGH SAID GASES FROM AN EMITTER TO A RECEIVER DOWNSTREAM OF THE EMITTER, AND C. TRANSMITTING SAID TIME MEASUREMENTS TO A COMPUTING DEVICE ADAPTED TO CALCULATE SAID MEANS SPEED FROM SAID TIME MEASUREMENTS; II. AUTOMATICALY DETERMINING THE CARBON CONTENT OF SAID GASES AT SAID GIVEN POSITION BH SPECTROGRAPHIC ANLYSIS; III. AUTOMATICALLY MEASURING THE TEMPERATURE OF SAID GASES AT SAID GIVEN POSITIION; IV. TRANSMITTING THE CALCULATED VALUE OF THE MEANS SPEED, THE DETERMINED VALUE OF THE CARBON CONTENT, AND THE MEASURED VALUE OF THE TEMPERATURE TO A COMPUTING DEVICE ADAPTED TO CALCULATE THE RATE OF DECARBURISATION OF SAID BATH FROM SAID VALUES; V. AUTOMATICALLY COMPARING THE CALCULATED VALVE OF THE DECARBURISATION RATE WITH A PREDETERMINED INSTANTANEOUS OPTIMUM VALUE; VI. AUTOMATICALLY GENERATING A SIGNAL REPRESENTATIVE OF THE DIFFERENCE, IF ANY, BETWEEN SAID CALCULATED VALUE AND SAID PREDETERMINED INSTANTANEOUS OPTIMUM VALUE; AND VII. AUTOMATICALY REGULATING AT LEAST ONE OF SAID REGULABLE REFINING CONDITIONS IN ACCORDANCE WITH SAID SIGNAL SO AS TO REDUCE OR ANNUL SAID DIFFERENCE.

Claim 2

A METHOD OF MONITORING AND CONTROLLING A PIG IRON REFINING OPERATION IN WHICH AN OXYGEN-CONTAINING GAS IS BLOWN FROM ABOVE BY MEANS OF A LANCE ONTO A BATH OF MOLTEN PIG IRON IN A VESSEL, REFINING AGENTS ARE FED INTO THE VESSEL, AND THE GASES LEAVING THE VESSEL ARE WITHDRAWN THROUGH A HOOD; THE REFINING OPERATION TAKING PLACE UNDER REGULABLE REFINING CONDITIONS COMPRISING THE HEIGHT OF THE LANCE ABOVE THE BATH, THE RATE OF FLOW OF GAS THROUGH THE LANCE, AND THE RATE AT WHICH REFINING AGENTS ARE FED IN; THE METHOD COMPRISING THE STEPS OF I. AUTOMATICALLY DETERMINING THE MEANS SPEED OF SAID GASES AT A GIVEN POSITION IN THE HOOD AT WHICH THE CO IN SAID GASES HAS BURNT TO CO2 AND PRIOR TO DUST REMOVAL OR DRYING OF SAID GASES, BY A AUTOMATICALLY MEASURING THE TIME TAKEN BY AN ACOUSTIC WAVE TO TRAVEL THROUGH SAID GASES FROM AN EMITTER TO A RECEIVER UPSTREAM OF THE EMITTER, B. AUTOMATICALLY MEASURING THE TIME TAKEN BY AN ACOUSTIC WAVE TO TRAVEL THROUGH SAID GASES FROM AN EMITTER TO A RECEIVER DOWNSTREAM OF THE EMITTER, AND C. TRANSMITTING SAID TIME MEASUREMENTS TO A COMPUTING DEVICE ADAPTED TO CALCULATE SAID MEANS SPEED FROM SAID TIME MEASUREMENTS; II. AUTOMATICALY DETERMINING THE CARBON CONTENT OF SAID GASES AT SAID GIVEN POSITION BH SPECTROGRAPHIC ANLYSIS; III. AUTOMATICALLY MEASURING THE TEMPERATURE OF SAID GASES AT SAID GIVEN POSITIION; IV. TRANSMITTING THE CALCULATED VALUE OF THE MEANS SPEED, THE DETERMINED VALUE OF THE CARBON CONTENT, AND THE MEASURED VALUE OF THE TEMPERATURE TO A COMPUTING DEVICE ADAPTED TO CALCULATE THE RATE OF DECARBURISATION OF SAID BATH FROM SAID VALUES; V. AUTOMATICALLY COMPARING THE CALCULATED VALVE OF THE DECARBURISATION RATE WITH A PREDETERMINED INSTANTANEOUS OPTIMUM VALUE; VI. AUTOMATICALLY GENERATING A SIGNAL REPRESENTATIVE OF THE DIFFERENCE, IF ANY, BETWEEN SAID CALCULATED VALUE AND SAID PREDETERMINED INSTANTANEOUS OPTIMUM VALUE; AND VII. AUTOMATICALY REGULATING AT LEAST ONE OF SAID REGULABLE REFINING CONDITIONS IN ACCORDANCE WITH SAID SIGNAL SO AS TO REDUCE OR ANNUL SAID DIFFERENCE.