Apparatus for applying refractory coating to the roof linings of electric arc furnaces

An upstanding support affixed to the floor of a plant adjacent an electric-arc furnace and having a truss member rotatably attached thereto. The truss member at its free end has a vertical support member rotatably attached thereto and upstanding therefrom. The vertical support at its upper end has affixed thereto a radius arm member. The radius arm has the same radius of curvature as the roof lining of the electric-arc furnace. A refractory spraying unit is attached to, and is movable back and forth along the length of, the radius arm. When the roof of the electric-arc furnace is swung outwardly of the furnace between heats, the truss is swung about the upstanding support to carry the vertical support and radius arm directly beneath the furnace roof. Rotation of the radius arm and movement of the spraying unit along the length of the radius arm causes the roof lining to be coated with refractory.