method and device for determining the veraenderlichen carbon content in hot metal

摘要

1,127,055. Measuring carbon content of ore electrically. UNITED STATES STEEL CORP. Aug. 11, 1966 [Aug.26, 1965], No.36052/66. Heading G1N. The quantity of carbon removed during the refining of a bath of iron ore in a fuel-fired furnace is determined by measuring the difference between the carbon input to and output from the furnace. The carbon input is determined by positioning a first potentiometer slider 6 in accordance with the mass flow-rate of fuel, followed by a second potentiometer slider 16 positioned in accordance with the predetermined percentage of carbon content of the fuel. Thus the signal at 16 represents the rate of carbon input to the furnace via the fuel. The carbon output is determined by positioning a potentiometer slider 22 in accordance with the percentage of CO 2 in the waste gas, the potentiometer 24 being fed with a voltage derived from a transducer 27 measuring the mass rate of flow of waste gas and modifying this voltage by variable resistors 25, 26 so that the signal at slider 22 represents mass rate of carbon leaving the furnace via waste gas. The difference between the signals on sliders 16, 22 is obtained at 31, representing the rate of carbon removal from the iron ore and is integrated at 32. A divider 34 is fed with this signal and a voltage preset at 33 representing the initial weight of the iron ore charge, whereby the output signal from 34 is proportional to the percentage of carbon removed from the bath. This is subtracted at 36 from a preset signal at 35 representing the initial percentage of carbon in the charge, obtained e.g. by chemical analysis, giving a voltage representing the percentage of carbon remaining in the bath. The measurements made also enable the weight of metal in the bath to be calculated.