Real-time optical diagnostics for the basic oxygen steelmaking process
This article deals with the development of real-time optical diagnostic techniques for process control in basic oxygen steelmaking. Results are presented of pilot-scale feasibility experiments conducted in the two-ton basic oxygen furnace (BOF) at Bethlehem Steel Corporation`s Homer Research Laboratories. Two line-of-sight optical techniques are being evaluated for determining the concentration and temperature of infrared-active gases in the BOF off-gas. The primary objective is to relate the concentration of these gas-phase species to the carbon content of the molten metal, and thereby provide a real-time indication of the process endpoint. Three cw lasers were used to measure the extent of beam attenuation at three different wavelengths in the particle-laden off-gas. The primary attenuation mechanism appears to be scattering by a dense, sub-micron diameter FeO fume. Initial infrared emission experiments with a Fourier transform infrared spectrometer at 1-cm{sup {minus}1} spectral resolution show partially resolved lines in the P-branch of the fundamental CO ground state and first hot-band transitions; CO{sub 2} bandheads are also clearly observed at 2384 and 2397 cm{sup {minus}1}. A second set of experiments was conducted to test the feasibility of oxygen-lance based fiber-optic imaging/pyrometric sensors for measurements of melt temperature and reaction zone properties. During bottom injection of nitrogen, clearly defined images of the melt/slag surface were obtained using both visible and near-infrared video systems. During oxygen blowing, optical emission from the hot spot was observed to fluctuate widely, with characteristic frequencies in the range of 3--10 Hz. Near the end of the process, the emission is characterized by periodic intensity bursts, interpreted as individual ignition events of duration 10--50 msec. Hot spot temperatures were calculated from the emission at 800 and 950 nm wavelengths using a grey-body assumption.
- Research Organization:
- Sandia National Labs., Livermore, CA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC04-76DR00789
- OSTI ID:
- 10139319
- Report Number(s):
- SAND-93-8409; CONF-9210213-5; ON: DE93009451
- Resource Relation:
- Conference: 1992 Combustion Institute fall meeting of the western states section,Berkeley, CA (United States),12-13 Oct 1992; Other Information: PBD: Feb 1993
- Country of Publication:
- United States
- Language:
- English
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