Model-Based Monitoring of Basic Oxygen Furnace

In‐Situ Measurement of CO‐ and CO2‐Concentrations in BOF Off‐Gas

“…The off‐gas parameters of the BOF process are high temperatures (1,400–1,600 °C), high off‐gas volumes (∼60–80 m 3 (STP)/t crude steel) with a high amount of pure iron and iron‐oxide dust particles in a micrometer range (∼ 15–20 kg/t crude steel), so‐called “brown smoke”, and gas compositions containing 60–80 vol.‐% {CO} and 5–20 vol.‐% {CO 2 } 4, 5, 21. The evaluation of available optical measurement methods shows, that the application of passive FTIR spectroscopy is advantageous for the measurement of hot gases, because no additional external signal source is required; instead the internal heat of the gas is used as radiation source.…”

BOS Vessel Vibration Measurement for Foam Level Detection

“…Mats BRÄMMING, 1,5) In the BOS process liquid slag together with dispersed metal droplets, solid particles and process gases form an expanding foam. Certain process conditions may lead to excessive foam growth, forcing foam out through the vessel mouth, an event commonly known as 'slopping'.…”

“…A common method of recording slopping is image analysis utilizing surveillance cameras that cover either the area underneath the vessel 5) or the converter mouth.…”

“…As the foam is an acoustical insulator, the measured noise level decreases with increasing foam height. Other methods utilize oxygen lance vibration, 2,6) radio waves, 5,7) micro waves 8,9) or radar. 10) Finally, some form of indirect foam level control can be based on off-gas data.…”

“…The most common method today for controlling the foam level is the 'sonicmeter', where a microphone, placed in the lower stack 2,3) or close to the vessel mouth, 4,5) is used to monitor process noise, mainly created by the oxygen jet. As the foam is an acoustical insulator, the measured noise level decreases with increasing foam height.…”