Lid for electric arc furnace for melting steel - has arched main-part and central parts of fire resistant material with iron@ plate seamlessly surrounding central part with air-gap to main part

摘要

Arc furnace roof presents a vaulted ring disc shaped watercooled main steel part placed on the vessel and with a centre hole fitted with a refractory vaulted centre piece. The centre piece has electrode passage holes and is enclosed without clearance by a solid sheet ring fixed to the centre piece between this and the main part of the roof. The ring is inserted in the centre hole so as to leave an air gap between them and is held from above by a support which also completes metal contact between ring and the main part of the roof. The sheet metal ring (7) should be free of direct contact with coolant pipes both on the surface of the outside casing of the ring within the air gap and on the bottom edge of the ring (11) facing into the furnace. USE/ADVANTAGE - Electric steelmaking. Arcing between electrodes and roof is kept clear of coolant circuit, giving extended roof life.