Improvements Achieved From Tenova's Upgrade of the Reheat Furnace Combustion System at Nucor Steel-Hertford County

摘要

Nucor Steel, the largest steel producer in the United States and largest mini-mill steelmaker, operates a 1.3 million ton per year plate mill at its Hertford, NC facility. It produces thicknesses of 1/4" to 3", and widths of 72" to 125" for a wide range of industries. The facility, constructed in 1999, includes a melt shop, continuous caster, reheat furnace, rolling mill, and a cooling bed. Nucor also has hot leveling, cold leveling, side trimming, plate marking, and heat treating capabilities.The reheat furnace, shown in Figure 1, is a walking beam/walking hearth type furnace that heats 6" to 10" thick slabs from either a hot charge or cold charge condition to a discharge temperature of about 2350°F. Slabs are lifted from the charge table and then charged into the furnace by three charge machines that can work either independently or synchronized. While traveling through the furnace, the slabs are conveyed on water-cooled skids, allowing for the slabs be heated from both the top and bottom burners. Finally, the slabs are discharged from the furnace by three extractor machines, which set the slabs on the mill roll table.