In Study Of Molten Iron Temperature On-line Monitoring System On AOD Furnace Based On The Technology Of Optical-fiber Colorimetric Thermometer

In the process of Argon Oxygen Refining Cr (Mn) alloy,temperature measurement have a decisive significance in performance of all aspects of smelting products. If the temperature is too high,then the loss of oxygen absorber in the products will be enlarged and their ability to reduce oxygen will be weaken.As a result,phenomenons like crack and subcutaneous bubbles will be easy to occur and sundry inside ferrosilicon products will be more;Meanwhile,if the temperature is too low,liquidity between molten iron and slag will be worse and impurities in molten iron will not be easy to flip,which makes it is not suitable for deoxygenation,decarburization,dephosphorization and desulfuration. Online measurement of temperature in the process of AOD furnace smelting will help to improve automation of the metallurgical process.This paper choosed optical-fiber colorimetric pyrometry to monitor molten metal temperature on AOD furnace smelting process. The researches mainly included:1.In the process of Argon Oxygen Refining Cr (Mn) alloy, temperature measure-ment have a decisive significance in performance of all aspects of smelting products. If the temperature is too high,then the loss of oxygen absorber in the products will be enlarged and their ability to reduce oxygen will be weaken.As a result,phenomenons like crack and subcutaneous bubbles will be easy to occur and sundry inside ferrosilicon products will be more;Meanwhile,if the, temperature is too low,liquidity between molten iron and slag will be worse and impurities in molten iron will not be easy to flip,which makes it is not suitable for deoxygenation,decarburization,dephosphorization and desulfuration.Online measurement of tem-perature in the process of AOD furnace smelting will help to improve automation of the metallurgical process.2.First,through the study of the structure of AOD Furnace,the oxygen blowing gun at the bottom of AOD furnace is selected as a collection point of optical signals.Bottom blowing oxygen lance blows smelting gases into furnace and receives the optical intensity of hot metal in the furnace in its end at the same time.Then,Sapphire Fiber is used to transmit optical signals to the location a little far away from the furnace.After splitting, filtering, photovoltaic conversion, optical amplification and circuit processing, temperature measurement results are obtained. Last,programs written in LabVIEW in the Supervisory Computer processs measurement data and realize Real-time temperature display,temperature curve drawing,historical data query,data backup and preserve-ation,temperature limit alarm setting and other operations. 3.This essay discusses emission rates and messwert in the method of Least squares,analyzes all sorts of possible sources of interference in the measurement system,and simulates the ratio of the two electric signals measured. In order to verify the accuracy of temperature,conducted an adjustable light source temperature experiment;In order to improve the accuracy of fiber optic colorimetric thermometer system,conducted a intermediate frequency furnace temperature experiment simulating AOD furnace working state in the laboratory; In order to improve the accuracy of fiber optic colorimetric thermodetector during the smelting process of AOD furnace,and to adapt to the scene bad working environment,did a 10t AOD furnace temperature field experiment in Steel Group in Jilin Ferroalloy Plant;In order to eliminate the temperature changes caused by the exchange of the bottom blowing gas and liquid iron,and to improve accuracy of each sample value during the process of temperature measurement,establish-ed a temperature compensation mode based on the radiation absorption properties of gas-liquid interface and the functional relationships.Experimental results bear out the supposition of the accuracy of temperature measurement colorimetricthermometer, and precision production more in line with the requirements of AOD furnace.This design of fiber-line temperature measurement system than the color used in the AOD furnace production will play a guidance on the role of the industry.