Method and apparatus for continuous casting of metals

Apparatus for casting metal strip by continuous belt casting comprising:

• (a) a pair of continuous belts formed of a heat conductive material mounted one above the other;
• (b) a pair of at least two pulleys including an entry pulley and an exit pulley, each of said belts being mounted on one entry pulley and one exit pulley and passing around the entry pulley whereby the belts define a curved surface about said entry pulley and a substantially linear surface after the belt passes around the entry pulley, the entry pulleys being mounted one above the other so that the belts, as they pass around the entry pulleys, define a gap of fixed dimension;
• (c) a pair of pinch rolls located between the entry pulleys and the exit pulleys adjacent the linear surface of the belts, the pinch rolls being positioned one above the other and having a gap therebetween, with the belts passing over the pinch rolls and defining a pinch roll nip therebetween, said nip lying in a plane defined by the axes of the pinch rolls, the nip having a gap that is smaller than the gap at the entry pulleys so that the linear surfaces of the belts converge toward each other and form a tapered molding zone therebetween;
• (d) nozzle means for supplying a molten metal to the linear surface of each belt, and the nozzle means having a tip extending to both belts and positioned after the gap at the entry pulleys, wherein the tip, along with the linear surfaces of the belts and the pinch roll nip define the tapered molding zone so that the last point of the molten metal to freeze is near the pinch roll nip and the metal strip is substantially solidified at the pinch roll nip;
• (e) edge containment means for preventing flow of molten metal beyond the edge of the converging belts in the molding zone, the edge containment means operating to accommodate a progressively smaller distance between the edges of the belts that occurs as a result of the linear surfaces of the belts converging toward each other in the tapered molding zone;
• and
• (f) means associated with the pinch rolls to control the spacing therebetween so that the substantially solidified cast metal strip has a thickness that is greater than the nip between the pinch rolls, and the nip thereby provides a compressive force on the substantially solidified cast strip at the pinch roll nip sufficient to cause the cast strip to have a thickness profile that substantially matches the gap of the pinch rolls.

A method for casting of metals by continuous belt casting comprising the steps of:

• (a) introducing molten metal with a nozzle between a pair of belts formed of a heat conductive material, each belt moving around pulleys, including an entry pulley and an exit pulley, wherein said nozzle having a tip extending to both belts and positioned after the gap of entry pulleys, a pair of pinch rolls disposed between the entry pulleys and the exit pulleys, the pinch rolls defining a nip therebetween, with the nip lying in a plane defined by the axes of the pinch rolls substantially perpendicular to the belts, each belt passing around the entry pulley defines a curved surface about the entry pulley and a substantially linear surface after the belt passes around the entry pulley, the substantially linear surfaces converging toward each other as they pass from the entry pulleys to the pinch rolls to define a tapered molding zone therebetween;
• (b) regulating the speed of the moving belts and the gap between the pinch rolls at the nip thereof so that the last point of the molten metal to freeze is near the pinch roll nip and solidification of the molten metal is substantially complete in the tapered molding zone to form a strip of cast metal having a thickness greater than the thickness of the pinch roll nip;
• and
• (c) advancing the cast strip to the pinch roll nip to effect a compressive force on the substantially solidified cast strip at the nip sufficient to cause elongation thereof so that the cast strip is in compression in the direction of travel after exiting from the pinch roll nip to minimize cracking of the cast strip.

A method for casting of metals by continuous belt casting comprising the steps of:

• (a) introducing molten metal with a nozzle between a pair of casting belts formed of heat conductive metal, each of said belts moving around pulleys, including an entry pulley and an exit pulley, wherein said nozzle having a tip extending to both belts and positioned after the gap of the entry pulleys, a pair of pinch rolls disposed between the entry pulleys and exit pulleys, the pinch rolls defining a nip therebetween, with the nip lying in a plane defined by the axes of the pinch rolls substantially perpendicular to the belts the belts defining a molding zone therebetween and each belt, as it passes from the entry pulleys to the pinch rolls, defines a linear tapered molding zone surface;
• (b) regulating the speed of the moving belts and the gap between the pinch rolls at the nip thereof so that the last point of the molten metal to freeze is near the pinch roll nip and solidification of the molten metal is substantially complete at the pinch roll nip to form a strip of cast metal having a thickness greater than the gap between belts at the pinch roll nip;
• (c) advancing the cast strip to the pinch roll nip to effect a compressive force on the substantially solidified cast strip at the nip sufficient to cause elongation thereof so that the cast strip is in compression in the direction of travel after exiting from the nip to minimize cracking of the cast strip;
• and
• (d) cooling each of the belts to substantially remove the heat transferred to the belt from the molten metal and the cast strips.