Abstract: The mold is equipped with a casting ring 6 which is formed by clamping together four generally rectilinear wall segments 8 that are, first, arranged like the sides of a picture frame about the rabbet 52 of a rectangular case 10, and then abutted together, sash-like, at their mitered ends 80, to form a ring, the casting surface 9 of which will produce the rectangular cross-sectional outline common to sheet ingot or the like, when molten metal is fed through the ring. The clamping action is produced by a set of screws 94 at the corners 10' of the case, and after the ring 6 is clamped about a pair of spaced, axially opposing lips 54 and 60 on the case and an annular plate 14 thereabove, the plate 14 is clamped to the top of the case, to secure the ring in place and seal the axial ends of the ring against fluid flow thereacross.

Abstract: Close control of the direct cooling rate is achieved by bubbling a substantially insoluble gas into the curtain-forming coolant as it is about to discharge onto the emerging ingot. The resulting bubble-entrained curtain of coolant experiences an increased velocity, and the increase is not accompanied by a reduction in the thermal conductivity of the coolant. Instead, the bubble-entrained coolant appears to have a scrubbing effect on the metal, which breaks up any film and reduces the tendency for film boiling to occur at the surface of the metal, thus allowing the process to operate at the more desirable level of nucleate boiling, if desired. This in turn makes it possible to regulate the cooling rate by selective use of the bubbling effect, including turning the effect on and off to allow film boiling to occur when desired, such as in the butt forming stage of the casting operation.

Abstract: One end opening of an open ended mold cavity has a diameter smaller than the peripheral wall of the cavity and a molten metal mass is introduced to the cavity by continuously filling the one end opening with the mass so that the molten metal splays about the inner peripheral edge of the opening to assume a cross-section between the ends of the cavity having a divergent/convergent outline, the intermediate continuum of which between the planes of maximum divergence and minimum convergence thereof, has a peripheral outline corresponding generally to the outline of the cavity at the peripheral wall thereof. A graphite or graphite-like ring is circumposed about the axis of the cavity in the peripheral wall thereof to form a solid but fluid permeable wall section that is disposed to define the peripheral outline of the intermediate continuum of the metallic mass.

Abstract: One or more top-opening mold cavity defining members are supported in the chamber of a coolant box adapted for the flow of liquid coolant therethrough about the members. Each member is supported in a telescoping assembly in which the top opening of the member is co-axial with an opening in the top of the chamber to enable molten metal to be introduced to the cavity of the member through the respective top openings of the chamber and the member. Moreover, each member has a greater outer peripheral diameter transverse the axis than the top opening of the chamber, and is engaged with the top of the chamber about the opening thereof in a first horizontal plane of the box. The member is also engaged with the defining surfaces of the chamber in a second horizontal plane of the box spaced below the aforesaid first horizontal plane of the box by a vertical gap.