Top pour shroud

An apparatus for providing a protective gas shroud around molten metal being teemed into an ingot mold from a ladle or the like having secured to the bottom thereof a slide gate assembly, said slide gate assembly comprising a fixed apertured plate,a movable apertured plate, a main housing secured to the bottom of the ladle providing a slideway and a spring carriage secured in the slideway of the main housing and said spring box carriage carrying and biasing the movable apertured plate against the stationary apertured plate, piston means for moving the spring box carriage within the main housing to bring the apertures in said plates into and out of registry, the improvement comprising:

• (a) an elongate nozzle extending downwardly from the movable apertured plate;
• (b) a plenum box extending downwardly from and secured to the underside of the spring box carriage to be carried thereby, said plenum box having an opening in the top thereof to receive the downwardly extending nozzle and means to form a rough seal around the periphery of the nozzle where it extends through the top of the plenum box;
• (c) a bracket fixed to the plenum box and extending away from it;
• (d) a shaft secured for rotation relative to said bracket with lifting forks fastened thereto;
• (e) a hood telescopically extendable and retractable with respect to the plenum box, said plenum box having trunnions fixed thereto extending therefrom for engaging distal ends of lifting forks, said hood having a flange skirt extending outward from the lower edge thereof;
• (f) piston means extending from said bracket for causing rotation of the shaft thus extending and retracting the hood to accommodate varying distances between the ladle and the ingot mold;
• and
• (g) means to introduce a protective gas into the plenum box;
• whereby after the ladle is aligned with the mold into which hot metal is to be teemed, the piston may be permitted to lower the hood until the skirt flange rests upon the top edge of the mold or hot top and the slide gate can be opened dragging the hood over the top of the mold or hot top into alignment with the mold.

In an apparatus for providing a protective gas shroud around molten metal being teemed into an ingot mold from a ladle or the like having secured to the bottom thereof a slide gate assembly, said gate assembly comprising a fixed apertured plate, a movable apertured plate, a main housing secured to the bottom of the ladle providing a slideway and a spring box carriage secured in the slideway of the main housing and said spring box carriage carrying and biasing the movable apertured plate against the stationary apertured plate, piston means for moving the spring box carriage within the main housing to bring the apertures in said plates into and out of registry, the improvement comprising:

• (a) an elongate nozzle extending downwardly from the movable apertured plate;
• (b) a plenum box extending downwardly from and secured to the underside of the spring box carriage to be carried thereby, said plenum box having an opening in the top thereof to receive the downwardly extending nozzle and means to form a rough seal around the periphery of the nozzle where it extends through the top of the plenum box;
• (c) a bracket fixed to the plenum box and extending away from it;
• (d) a shaft secured for rotation relative to said bracket with lifting forks fastened thereto;
• (e) a hood telescopically extendable and retractable with respect to the plenum box, said plenum box having trunnions fixed thereto extending therefrom for engaging distal ends of lifting forks, said hood having a flange skirt extending outward from the lower edge thereof;
• (f) piston means extending from said bracket for causing rotation of the shaft thus extending and retracting the hood to accommodate varying distances between the ladle and the ingot mold;
• and
• (g) means to introduce a protective gas into the plenum box;
• whereby after the ladle is aligned with the mold into which hot metal is to be teemed, the piston may be permitted to lower the hood until the skirt flange rests upon the top edge of the mold or hot top and the slide gate can be opened dragging the hood over the top of the mold or hot top into alignment with the mold.

A method of teeming molten metal into ingot molds from a ladle havng a slide gate thereon comprising the steps for:

• (1) providing an apparatus secured to the bottom of the slide gate having:
• (a) a plenum box sealed to and extending downwardly from the sliding part of the slide gate;
• (b) a hood telescopically extendable and retractable with respect to the plenum box and forming a rough sliding seal therewith, said hood having a skirt flange at the bottom thereof, the width of said skirt flange in the direction of movement of the slide gate being greater than the maximum slide gate movement;
• (c) means fixed relative to the plenum box to extend and retract the hood to accommodate varying distances between the ladle and the ingot mold;
• and
• (d) means for introducing a protective gas in the plenum box;
• (2) purging the ingot molds and covering with a burn away temporary cover;
• (3) placing the ladle over the ingot molds and lowering the hood;
• and
• (4) opening the slide gate dragging the hood over the top of the ingot molds.