Abstract: Molten steel is conducted by a tubular shroud interconnecting a slide gate at a bottom tap hole of a ladle with the molten steel in an underlying tundish of a continuous caster. The flow path is confirmed to be isolated from contaminants in atmospheric air by applying a source of partial vacuum to the internal cavity of tubular shroud to allow prevailing atmospheric pressure acting on molten steel in a tundish to push molten steel upwardly in the internal cavity of the tubular shroud. A measure of the partial vacuum in the cavity of the shroud is used to assess the integrity of the gas tight seal. Before and after the integrity of the gas tight seal is determined, a three way valve is used to apply an inert gas to the volume in the cavity of the shroud.

Abstract: A scrap charging apparatus for an electric arc furnace includes a scrap holding bunker having diverging side walls extending between end walls separated by a scrap discharge opening supplying scrap from a fall space in the bunker to a scrap discharge chute. The end wall remote to the scrap discharged opening of the chute slopes at an acute angle to organized scrap entering the discharged opening. A throat opening for scrap passing into the scrap discharge chute is controlled by a pivotal scrap jam relief gate moveable between a scrap metering position, a relief position and a scrap compacting position.

Abstract: An electric steel-making furnace has a furnace roof carried by an upper furnace shell on a lower furnace shell to substantially envelop an atmosphere above liquid steel and slag floating thereon in the lower furnace shell. A transfer car supports the lower furnace shell for transport from a furnace-operating site to a remote exchange site for exchanging one or more of the furnace roof, the upper furnace shell and the lower furnace shell. The furnace transfer car has a furnace support platform engaged with the lower furnace shell and supported for tilting of the furnace on the transfer car by actuators at the furnace operating site in a direction to increase the depth of slag at the deslagging passageway for decanting slag floating on liquid steel in the lower furnace shell. Actuators are also provided to tilt the furnace on the transfer car to increase the depth of liquid steel at a tap hole assembly during tapping of a steel heat.

Abstract: A bearing system for accommodating angular movements occurring during operation of a linear actuator in a lifting structure for a ladle containing liquid steel in a continuous casting installation. Annular bearings on a piston and in an end wall of a piston and cylinder assembly allow free rotation of the piston about a first axis during controlled excursions of translating motion by the piston along the cylinder. A first attachment shaft is joined by cylindrical bearings to the arms of a first clevis for only sliding rotational motion about a second axis. A second attachment shaft secured to a second clevis carries a cylindrical bearing between the clevis arms for only sliding rotational motion about a third axis parallel with the second axis. A saddle is secured to an attachment on the piston rod and having an elongated annular load-bearing surface defining a fourth axis extending along a force transmitting junction with the first attachment shaft.

Abstract: A mold for the continuous casting of beam blanks is provided with a casting passage which, as seen in a transverse plane of the mold, has two lateral portions for forming the flanges of a beam blank and a central portion for forming the web of the beam blank. The thickness of the mold wall is reduced in the central portion of the casting passage in order to improve heat transfer.

Abstract: An existing steel making installation having a basic oxygen furnace facility is converted to an electric arc furnace facility for refining steel by modifying the furnace support pedestals to form spaced apart horizontal rail support pads and spaced apart rails are mounted on the pads and a superstructure extending horizontally at one side of the space formally occupied by the basic oxygen furnace. An electric arc furnace is mounted on a furnace transfer car for movement along newly installed horizontal rails between a furnace operating position and a furnace exchange position. The electric furnace having a tapping orifice for discharging treated steel and a slag discharge trough. Ladle transfer cars previously used for handling slag and steel from the basic oxygen furnace are reused for the same purpose during operation of the electric arc furnace. A fume opening in the electric furnace roof is connected by a vertical fume section and an elbow to the existing fume system.

Abstract: An electric furnace includes a stationary lower shell having a sloping floor extending downwardly to a tap hole to always maintain a sufficient ferrostatic head three times the tap hole for slag free tapping. The configuration of the refractory for containing a heat, is sufficient to maintain a liquid metal heel of at least 70% of the heat before tapping for maintaining flat bath operation during refining a steel melt. An upper furnace shell is supported on the lower furnace shell and a furnace roof is supported by the upper furnace shell. The entire furnace is mounted on a furnace transfer car that is anchored for stationary operation but moved to a furnace exchange position for servicing any of the components making up the furnace. The furnace roof and/or upper furnace shell may be supported at a furnace operate position while the lower furnace shell is transported to the furnace exchange position.

Abstract: Disclosed is an electrode control system for an electric arc furnace having a furnace transformer. The electrode control system includes a current transformer for measuring operating current of the electrode and a voltage transformer for measuring operating voltage of the electrode. An active power transducer is connected to the current transformer and the voltage transformer for calculating active power of the electrode from the measured operating current and operating voltage as a first output signal. A reactive power transducer is connected to the current transformer and the voltage transformer for calculating the reactive power of the electrode from the measured operating current and operating voltage as a second output signal. A programmable control unit is connected to the active power transducer and the reactive transducer for receiving the first and second input signals.

Abstract: A scrap charging apparatus for an electric arc furnace uses a skip hoist to supply scrap to a holding bunker having diverging end walls extending between converging side walls. The containment space for the scrap is increased by this wall arrangement and provides an impetus in the bunker for scrap flow to an underlying scrap delivery chute. The scrap delivery chute is formed by an elongated scrap carrying trough having a greater width than the exit width of the scrap holding bunker for delivering scrap to a charging opining for an electric arc furnace A superstructure supporting the scrap holding bunker at an elevated and lateral spaced location from the electric arc furnace. A ram controlled by a drive incrementally advances scrap along the scrap delivery chute for introducing successive preselected volumes of scrap to a charging opining for an electric arc furnace.