Dofasco`s No. 4 blast furnace hearth breakout, repair and rescue
- Dofasco Inc., Hamilton, Ontario (Canada)
On May 5, 1994, after producing 9.5 million metric tons of iron, Dofasco`s No. 4 Blast Furnace experienced a hearth breakout 250 millimeters below the west taphole. The hot metal spill caused a fire resulting in severe damage and 33 days of lost production. During a 26-day period, electrical wiring, water drainage systems and both tapholes were repaired. Recovery from an unprepared furnace stop of this length, with the deadman depleted is difficult. To aid with the rescue Hoogovens-designed oxygen/fuel lances were commissioned. The furnace recovery began with a lance in each taphole and all tuyeres plugged. Six days after startup the furnace was casting into torpedo cars, and after nine days operation had returned to normal. This incident prompted Dofasco to expand the hearth monitoring system to detect and prevent similar occurrences. During the repair, 203 new thermocouples were installed in the hearth, concentrating on the tapholes and elephant foot areas. These thermocouples were installed at various depths and locations to allow heat flux calculations. This hearth monitoring system has already identified other problem areas and provided valuable information about hearth drainage patterns. This information has allowed them to develop control strategies to manage localized problem areas.
- OSTI ID:
- 129077
- Report Number(s):
- CONF-9504182--; ISBN 0-932897-99-1
- Country of Publication:
- United States
- Language:
- English
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