ENERGY SAVING OF SLAB REHEATING FURNACES BY IMPROVEMENTS OF REFRACTORIES

Slab reheating furnaces in the steel making process consume a lot of thermal energy; some of which is lost through refractories lining to the furnaces roof, wall, bottom and beams/supports. The energy loss extends to 10-30 percent of the energy input from fuel. Therefore, the improvement of the insulation of refractories is important for saving energy in slab reheating furnaces. On the other hand, refractories must also have improved durability to increase productivity due to the high occupancy rate of furnaces. In this paper, we report the recent results of energy saving by improving refractories materials and structures for slab reheating furnaces at Oita-works in Japan. As for the beams/supports, which lose large amount of energy to cooling water, the energy loss was greatly reduced by applying three-layered insulation structure and the durability of refractories was improved.