Abstract: A stopper drive mechanism is removably mounted on a molten metal vessel having a discharge opening and is adapted to move a stopper into and out of closing engagement with the discharge opening. A piston and cylinder unit of the stopper drive mechanism is operably connected with the stopper and has a valve unit connected thereto for controlling the piston and cylinder unit. The piston and cylinder unit comprises a cylinder that defines a working chamber with a piston slidably disposed therein. The piston has the same effective working area on opposite sides thereof. The valve unit comprises a control valve for controlling the flow of hydraulic fluid to and from the opposite sides of the piston and a bypass valve that is adapted to selectively communicate opposite sides of the piston with each other for manual movement of the stopper.

Abstract: A housing assembly of a sliding closure unit for controlling the discharge of molten metal from a metallurgical vessel includes a housing member mounted on the metallurgical vessel adjacent an outlet thereof, and a cover member mounted on the housing member by joints to enable the cover member to pivot with respect to the housing member and to be removable therefrom. The joints include joint bases on at least four sides of each of the housing and cover members and including, for each of the housing and cover members, first and second oppositely spaced sides with the joint bases thereof defining parallel first and second joint axes, respectively, and third and fourth oppositely spaced sides with the joint bases thereof defining parallel third and fourth axes, respectively. The joint bases on each side of the cover member face joint bases of a respective side of the housing member.

Abstract: Molten metal is teemed through a discharge nozzle controlled by a shut-off device during which inert gas is injected into an inlet portion of the discharge nozzle. A reduction of the cross section of the discharge nozzle due to the formation therein of deposits is prevented by injecting at least a portion of the inert gas into the inlet portion in a pulse-like manner by controlling the supply of the inert gas with respect to time and volume. The inert gas may be supplied from a source as partial volumes through plural branch lines each provided with shut-off and control valves, and the operation of such valves may be programmed to control the duration and repetition period of the supply of each partial volume.

Abstract: An apparatus, for use with a metallurgical vessel for the continuous casting of molten metal through a discharge opening thereof, prevents solidification of the first charge of molten metal in the discharge opening. A first overflow pipe is mounted above the discharge opening, and a second overflow pipe is mounted about the first overflow pipe and defines therewith an annular recess. Within the recess is provided a material capable of effecting the flow characteristics of the first portion of the molten material to be discharged.