Abstract: A mill layout operating apparatus system and procedure for maximizing the recovery of exhaust or effluent gases from an electric arc metal refining or melting furnace is provided that makes use of a longitudinally extending scrap preheating bucket station providing ductway pad. The pad extends at its end to provide a down-positioned scrap loading station for each bucket immediately after its preheated content has been fed into the furnace preliminary to a second melting operation. At the same time, scrap buckets are positioned along the parallel stations of the ductway pad to preheat their scrap loads with the effluent or exhaust gas issuing from a smoke chest of the furnace and as generated by a preceding melting-down operation. The number of or capacities of the preheating buckets to be positioned on the ductway pad is proportioned to the amount of charge required for each furnace melting-down operation.

Abstract: A metal melting furnace is provided having an enclosing roof that has a refractory brim portion affixed to and carried by the side walls, and has a refractory crown portion that is adapted to be removably positioned to close-off and open a central charging opening defined and encompassed by the brim portion. The crown portion by-passes electrodes in its "down" position and is to be raised and lowered and swung into and out of a clearing position with respect to the charging opening. Exhaust fume from a side-positioned smoke hole of the furnace is directed either into and positively drawn through a side-positioned-preheating scrap container or through an exhaust chest for subsequent environmental treatment before discharge into the atmosphere.

Abstract: An electric arc melting furnace for metal has a roof liftably positioned on a funnel-shaped refractory mouth portion, has conventional electrode openings therethrough, and provides for a smoke hole through which fumes may be exhausted. A cooling fluid-receiving circulating metal duct is positioned to extend along and in a somewhat supporting relation with respect to an outer periphery of the funnel-shaped mouth portion for introducing cooling fluid into J-shaped, heat chambers that are positioned in a circumferentially spaced relation within and about a refractory side wall in such a manner as to provide for a maximum cooling action adjacent a sill area of the furnace. Cooling-fluid-receiving and circulating chambers in the side wall are, in effect, closed or sealed-off with respect to each other. Warmed fluid or air exhausting from the chambers in the side wall may be used for heating cooler areas inside the furnace, for outside furnace discharge for room heating, etc.

Abstract: An electric furnace roof having spaced-apart, inner and outer, cooling-fluid-circulating refractory tile or block-carrying metal ring structures is provided with an upwardly offset, outwardly extending, roof ledge segment which, with an aligned, cooperating furnace side wall segment defines a smoke hole open portion to the furnace. The side wall segment of the furnace wall, with the roof segment, also provides an inner smoke chest that is open to the smoke hole portion, and has an upwardly enlarged funnel shape, and is metal reinforced. The roof segment is provided with a cooling water circulating loop system which may be independent of cooling means supplying inner and outer, radially spaced-apart, metal ring structures of the roof. The roof is adapted to be raised and lowered as a unit in a conventional manner with respect to the furnace wall and to be swung to one side thereof for scrap-charging and maintenance purposes.

Abstract: A dual ring liftable and swingable roof for an electric furnace is provided with an outer, hanger-suspended, refractory tile, apron-defining roof portion between its outer fluid-cooled ring and its upwardly positioned inner ring. A central part of the roof is covered by refractory tile members that are hanger-suspended and that define spaced-apart, electrode-receiving and fume exhaust-discharging hole portions. An overhead metal frame structure has a pair of spaced-apart, water-jacketed, primary side beams that extend across the roof to support a centrally disposed air supply ductwork that extends about the hole portions, and that supplies cooling air to adjacent hanger and tile member. A quadrant arrangement of secondary beams is utilized, to connect the inner and outer ring members; one part of the secondary beams is also water-jacketed to connect opposite ends of the pair of primary beam members and provide a continuous flow of cooling fluid.

Abstract: A dual-ring roof is provided for an electric arc furnace which may be suspended for lift-off and on operation with respect to a receiving mouth ledge portion about a charging opening in the furnace. The rings are radially spaced with respect to each other to define inner and an outer refractory tile receiving areas; they are of structural metal construction and have jacketing for continuous circulation of cooling fluid therealong. An outer, sprung, refractory skirt section is carried in the area between the rings, and the inner ring has an upwardly spaced relation with respect to the outer ring and carries centrally thereof an inner, refractory, sprung section or dome. The inner, central refractory roof section is provided with electrode and fume exhaust hole portions therein. The fume hole portion is enclosing and defined by a fluid-cooled ring through which fluid circulates in tandem with fluid being circulated through the inner roof ring.