Continuous casting of molten metal with vertically flexible edge containment

Abstract

An approach for continuous casting of molten metals with vertically flexible edge containment is disclosed. A vertically flexible edge containment device can confine molten metal in a moving mold cavity of a continuous metal casting apparatus. In operation, the vertically flexible edge containment device is configured to flex in a vertical direction relative to a flow of the molten metal in the moving mold cavity. The flex in the vertical direction of the vertically flexible edge containment device corresponds with changes in one of a thickness and height of the molten metal in the moving mold cavity as the molten metal travels from an upstream mold region to a downstream mold region before leaving an exit end of the moving mold cavity.

What is claimed is: 
     
         1 . A continuous metal casting apparatus, comprising:
 opposing rotating casting surfaces forming a moving mold casting region therebetween that defines a moving mold cavity, the moving mold casting region having an upstream mold region and a downstream mold region; and   a molten metal injector to introduce molten metal into an entrance end of the moving mold cavity;   a vertically flexible edge containment device to confine the molten metal in the moving mold cavity as the molten metal solidifies, wherein the vertically flexible edge containment device is configured to flex in a vertical direction relative to a flow of the molten metal in the moving mold cavity, wherein the flex in the vertical direction of the vertically flexible edge containment device varies as a function of a length that the molten metal in the moving mold cavity is from the molten metal injector.   
     
     
         2 . The continuous metal casting apparatus of  claim 1 , wherein the vertically flexible edge containment device comprises a web of material extending between the upstream mold region and the downstream mold region that is configured to vary in height as the molten metal travels from the upstream mold region to the downstream mold region. 
     
     
         3 . The continuous metal casting apparatus of  claim 1 , wherein the vertically flexible edge containment device comprises an endless loop of material that moves along with the opposing rotating casting surfaces, wherein the endless loop of material is configured to vary in height between the upstream mold region and the downstream mold region, the height variation in the endless loop of material corresponding with the length that the molten metal in the moving mold cavity is from the molten metal injector. 
     
     
         4 . The continuous metal casting apparatus of  claim 1 , wherein the vertically flexible edge containment device comprises an endless edge dam formed of edge dam blocks that revolve in a preselected path with the opposing rotating casting surfaces about the moving mold cavity. 
     
     
         5 . The continuous metal casting apparatus of  claim 4 , wherein each edge dam block comprises:
 a lower dam block portion;   an upper dam block portion seated on the lower dam block portion; and   a mechanism for imparting a default force between the lower dam block portion and the upper dam block portion that pushes the lower dam block portion and the upper dam block portion apart from each other.   
     
     
         6 . The continuous metal casting apparatus of  claim 5 , wherein the lower dam block portion comprises a lower main body that extends from a cast side to a non-cast side and an upward protruding region that extends upward from the lower main body at the cast side, the upward protruding region and the lower main body each having a surface that slopes downward from the cast side towards the non-cast side. 
     
     
         7 . The continuous metal casting apparatus of  claim 6 , wherein the upper dam block portion comprises an upper main body that extends from the non-cast side to the cast side and a shelf region that expands out from the upper main body towards the cast side, the upper main body and the shelf region each having a lower surface that slopes upward from the non-cast side to the cast side, wherein the upward sloping lower surface of the shelf region sits on the downward sloping surface of the upward protruding region and the upward sloping lower surface of the upper main body sits on the downward sloping surface of the lower main body. 
     
     
         8 . The continuous metal casting apparatus of  claim 6 , further comprising an edge dam block compressor that is configured to impart a compressive load into the edge dam blocks at the non-cast side while the edge dam blocks are moving through the upstream mold region, the compressive load counteracting the default force between the lower dam block portion and the upper dam block of each of the edge dam blocks in the upstream mold region. 
     
     
         9 . The continuous metal casting apparatus of  claim 8 , wherein the compressive load compresses the edge dam blocks in the upstream mold region towards the cast side of the edge dam blocks, leading to an increase in height of the of the edge dam blocks to full height. 
     
     
         10 . The continuous metal casting apparatus of  claim 9 , wherein the imparting mechanism of each of the edge dam blocks in the upstream mold region is further configured to impart a decreasing force in response to the edge dam blocks being at full height, the decreasing force causing a decrease in height from full height to a compressed height as the edge dam blocks travel to the downstream mold region. 
     
     
         11 . A continuous metal casting apparatus, comprising:
 opposing rotating casting surfaces forming a moving mold casting region therebetween that defines a moving mold cavity, the moving mold casting region having an upstream mold region and a downstream mold region;   a molten metal injector to introduce molten metal into an entrance end of the moving mold cavity;   an endless edge dam formed of edge dam blocks that revolve in a preselected path with the opposing rotating casting surfaces about the moving mold casting region to provide a side boundary to the molten metal in the moving mold cavity as the molten metal travels from the upstream mold to the downstream mold region before leaving an exit end of the of the moving mold cavity as a slab of metal, wherein each edge dam block comprises:   a lower dam block portion;   an upper dam block portion seated on the lower dam block portion; and   at least one spring situated to impart a force into the upper dam block portion while the edge dam block is moving through the upstream mold region, the imparted force pushing the upper dam block portion laterally towards a non-cast side opposing a cast side, reducing full height of the edge dam block to a compressed height as the edge dam block travels through the downstream mold region.   
     
     
         12 . The continuous metal casting apparatus of  claim 11 , further comprising an edge dam block compressor that is configured to impart a compressive load into the edge dam blocks at the non-cast side while the edge dam blocks are moving the upstream mold region. 
     
     
         13 . The continuous metal casting apparatus of  claim 12 , wherein the compressive load leads to an increase in height of the of the edge dam block to full height. 
     
     
         14 . The continuous metal casting apparatus of  claim 11 , wherein the at least one spring of each edge dam block comprises a first spring and a second spring spaced apart from the first spring in the lower dam block portion about the cast side. 
     
     
         15 . A method for providing vertically flexible edge containment to molten metal in a moving mold casting region having an upstream mold region and a downstream mold region that defines a moving mold cavity in a continuous moving belt metal casting machine, the method comprising:
 introducing the molten metal into an entrance end of the moving mold cavity with a molten metal injector;   confining the molten metal in the moving mold cavity with a vertically flexible edge containment device as the molten metal travels from the upstream mold region to the downstream mold region before leaving an exit end of the of the moving mold cavity as a slab of metal; and   flexing the vertically flexible edge containment device in a vertical direction relative to a flow of the molten metal in the moving mold cavity, wherein the flex in the vertical direction of the vertically flexible edge containment device corresponds with changes in one of a thickness and height of the molten metal in the moving mold cavity as the molten metal travels from the upstream mold region to the downstream mold region before leaving the exit end of the of the moving mold cavity.   
     
     
         16 . The method of  claim 15 , wherein the flexing comprises varying a height of the vertically flexible edge containment device as a function of a length that the molten metal in the moving mold casting region is from the molten metal injector. 
     
     
         17 . The method of  claim 15 , wherein the vertically flexible edge containment device comprises one of a web of material extending between the upstream mold region and the downstream mold region, and an endless loop of material that moves along with opposing rotating casting surfaces in the continuous moving belt metal casting machine. 
     
     
         18 . The method of  claim 15 , wherein the vertically flexible edge containment device comprises an endless edge dam formed of edge dam blocks that revolves in a preselected path with opposing rotating casting surfaces about the moving mold casting region. 
     
     
         19 . The method of  claim 18 , comprising:
 applying a compressive load at a non-cast side of the edge dam blocks that are passing through the upstream mold region, the compressive load compressing the edge dam blocks in the upstream mold region towards a cast side of the edge dam blocks, leading to an increase in height of the of the edge dam blocks to full height; and   reducing the full height of the edge dam blocks to a compressed height as the edge dam blocks move from the upstream mold region into the downstream mold region.   
     
     
         20 . The method of  claim 19 , wherein the vertically flexible edge containment device enables opposing rotating casting surfaces in the casting machine that form the moving mold casting region to maintain uniform contact with the molten metal in the mold casting region, the uniform contact ensuring uniform heat extraction throughout the casting machine such that the metal at the exit end of the of the moving mold cavity has a uniform transverse temperature profile.