Abstract:
A vessel used for containing molten metal, e.g. a trough section for conveying molten metal from one location to another. The vessel has a refractory liner made of at least two refractory liner units positioned end to end, with a joint between the units, the units each having an exterior surface and a metal-contacting interior surface. A housing at least partially surrounds the exterior surfaces of the refractory liner units with a gap present between the exterior surfaces and the housing. Molten metal confinement elements, impenetrable by molten metal, are positioned on opposite sides of the joint within the gap, at least below a horizontal level corresponding to a predetermined maximum working height of molten metal held within the vessel in use, to partition the gap into a molten metal confinement region between the elements and at least one other region that may be used to hold equipment such as electrical heaters that may be damaged by contact with molten metal. Another embodiment employs refractory liner units of different thermal conductivity to maximize heat penetration into the molten metal from heaters in the gap, but to minimize heat loss at the inlet and outlet of the vessel where the end units contact the housing.
Abstract:
An exemplary embodiment provides a method of eliminating a shrinkage cavity in a metal ingot cast by direct chill casting. The method involves casting an upright ingot having an upper surface at an intended height. Upon completion of the casting, the lower tip of the spout is maintained below the molten metal near the center of the upper surface. The metal flow through the spout is terminated and a partial shrinkage cavity is allowed to form as metal of the ingot shrinks and contracts. Before the partial cavity exposes the lower tip of the spout, the cavity is preferably over-filled with molten metal, while avoiding spillage of molten metal, and then the flow of metal through the spout is terminated. These steps are repeated until no further contraction of the metal causes any part of the upper surface to contract below the intended ingot height.
Abstract:
An exemplary embodiment provides a method of eliminating a shrinkage cavity in a metal ingot cast by direct chill casting. The method involves casting an upright ingot having an upper surface at an intended height. Upon completion of the casting, the lower tip of the spout is maintained below the molten metal near the center of the upper surface. The metal flow through the spout is terminated and a partial shrinkage cavity is allowed to form as metal of the ingot shrinks and contracts. Before the partial cavity exposes the lower tip of the spout, the cavity is preferably over-filled with molten metal, while avoiding spillage of molten metal, and then the flow of metal through the spout is terminated. These steps are repeated until no further contraction of the metal causes any part of the upper surface to contract below the intended ingot height.
Abstract:
Exemplary embodiments of the invention relate to a vessel used for containing molten metal, e.g. a trough section for conveying molten metal from one location to another. The vessel has a refractory liner made of at least two refractory liner units positioned end to end, with a joint between the units, the units each having an exterior surface and a metal-contacting interior surface. A housing at least partially surrounds the exterior surfaces of the refractory liner units with a gap present between the exterior surfaces and the housing. Molten metal confinement elements, impenetrable by molten metal, are positioned on opposite sides of the joint within the gap, at least below a horizontal level corresponding to a predetermined maximum working height of molten metal held within the vessel in use, to partition the gap into a molten metal confinement region between the elements and at least one other region that may be used to hold equipment such as electrical heaters that may be damaged by contact with molten metal. Another embodiment employs refractory liner units of different thermal conductivity to maximize heat penetration into the molten metal from heaters in the gap, but to minimize heat loss at the inlet and outlet of the vessel where the end units contact the housing.