A three-plate slide valve closure includes an upper stationary plate fixed beneath an outlet in a liquid melt container, a lower stationary plate positioned at a location spaced from the upper stationary plate, and a slide plate mounted between the upper and lower stationary plates for sliding movement between open and closed positions. The upper stationary plate, the slide plate and the lower stationary plate have extending therethrough first, second and third flow-through openings, respectively, which are aligned when the slide plate is in the open position. At least the upper inlet portion of the third flow-through opening, adjacent the slide plate, has a dimension in the direction of movement of the slide plate which is at least twice as great as the dimension of the second flow-through opening in such direction of movement.

Metal filament forming apparatus including a casting crucible having a tapping orifice and a casting nozzle for ejecting molten metal from the crucible are described. The casting nozzle is characterized by having an externally replaceable orifice member. The casting nozzle comprises three parts: (1) a nozzle body providing a conduit for the molten metal in association with the tapping orifice; (2) a replaceable orifice member positioned at the lower end of the nozzle body; and (3) retaining means for holding the replaceable orifice member in sealing engagement with the nozzle body. The crucible is preferably provided with a stopper rod to permit discontinuation of metal flow through the nozzle, while holding molten metal in the crucible.

In order to unchoke the casting outlet of a vessel such as a casting ladle fitted with a casting tube for transferring molten metal to a tundish, a feed pipe is engaged in a lateral opening formed in the upper portion of the casting tube and guided within the tube until the end of the feed pipe opens in the vicinity of the casting outlet. The feed pipe is then connected to a supply of oxygen or similar oxidizing gas which is discharged in a jet onto the mass of solidified metal which obstructs the outlet. After the outlet has been cleared by melting of the mass of metal, the feed pipe is withdrawn and the lateral opening of the casting tube is sealed-off.

A fill tube assembly is for a casting mold. The fill tube assembly includes a fill tube having a tubular member with a receiving end, a mold-engaging end and an intermediate portion. The mold-engaging end has a tapered flange radially extending therefrom, the remainder of the tubular-member has a substantially uniform cross-section. A clamping assembly is structured to maintain a substantially leak-proof seal at the fill tube, casting mold interface while accommodating dimensional variations. The clamping assembly includes a gasket, a load ring, a clamping plate and a pre-load gap between the clamping plate and the casting mold and optionally includes a dimensional compensating ring. When tightened, the clamping plate biases the load ring against the flange thereby distributing a uniform load against the casting mold, compressing the gasket therebetween while narrowing the pre-load gap to accommodate dimensional variations. A method of use is also disclosed.

An apparatus and method for selectively draining melt material, such as molten salt, utilizes an unobstructed drain conduit detachably connected, as by screw threads, to a vessel containing the material. Two heaters are utilized for the conduit, a drain heater at the vessel and a plugging heater spaced from the vessel. The conduit is placed at the plugging heater and partially filled with a predetermined quantity of plugging material in flowable form. The plugging material is, typically, the same salt in particulate form and is retained in the conduit by any suitable closure. The plugging heater is energized to melt the plugging material and is then de-energized so that a solid plug of this material forms in the conduit. The conduit, including the plug, is removed from the closure and the plugging heater and is connected to the vessel when the drain heater is de-energized and when the vessel does not contain molten melt material, as when the vessel is empty or this material is solidified. The molten material is then established in the vessel with limited heat transfer to the conduit so that the plug does not melt. When the melt material is to be drained, the drain heater is energized to heat the conduit and melt the plug so that the melt material drains through the conduit. When the conduit is suitably configured, such a quantity of the melt material may remain in the conduit to form another plug when the drain heater is de-energized.