Application of Regenerative Burner for Ladle Preheating System of Electric Furnace

Ladles for molten steel from the electric furnace are preheated by gas burner which is established on the top of the lid while waiting for the next charge. Preheating temperature is about 1270K because of reducing thermal shock to ladle refractories. Exhaust gas temperature is so high in this case, that any recuperators made of metals can not endure. Then we could not recover such a high sensible heat of exhaust gas. NKK Corporation in collaboration with Nippon Furnace Kogyo Kaisha, LTD. have developed a regenerative burner applying the compact ceramic honeycomb regenerators. So NKK Corporation could establish the regenerative burner heating system on the top of the lid as the electric furnace ladle preheating system in Keihin Works. The newly constructed heating system has heating capacity of 680 kW per hour. As a result we obtain preheating air at about 1170K recovered from exhaust gas at about 1270K, and achieve over 50% energy saving. In addition, uniform heating of the regenerative burner decrease 50% temperature deviation (from 50K to 20K) inside the ladle compared with the conventional system. And the cost of ladle refractories is smaller than that of the conventional system.