Uniform distribution nozzle

Abstract

A uniform distribution nozzle for a twin roll caster adapted to extend along and above a pair of casting rolls having an unitary body and with a top member arranged along the top side of the unitary body. The top member having a plurality of molten metal metering nozzles spaced apart along the length of the body for transferring molten metal from a tundish and/or transition piece into an interior cavity in the uniform distribution nozzle and below the top member. The molten metal is further transferred from the interior cavity of the uniform distribution nozzle into a casting pool at the casting rolls.

What is claimed is: 
     
         1 . A uniform distribution nozzle for a twin roll caster adapted to extend along and above a pair of casting rolls and to deliver metal from a transition piece to a location above the pair of casting rolls and forming a casting pool of molten metal supported by the pair of casting rolls, the uniform distribution nozzle comprising:
 a unitary body formed of refractory and having a length configured to extend along a length of a casting pool in an axial direction of the pair of casting rolls, the body length extending at least 90% of the casting pool length,   a top member arranged along a top side of the body and including a plurality of molten metal metering nozzles spaced apart along the length of the body; and,   an interior cavity arranged within the body and below the top member, the interior cavity having a height extending from the top to a bottom of the body;   the body further including a plurality of outlet ports arranged below the top member and extending from the interior cavity to an exterior of the body, where the interior cavity is configured to receive molten metal from the plurality of metering nozzles to form an interior molten metal pool and discharge the molten metal from the uniform distribution nozzle through the plurality of outlet ports and into the casting pool during casting.   
     
     
         2 . The uniform distribution nozzle of  claim 1 , where the body further includes a pair of end portions, each end portion located at one end of a pair of opposing ends of the body length, each end portion including at least a pair of triple point outlet ports extending from the interior cavity and to the exterior of the body at a location above an intended height of the casting pool, each triple point outlet port is configured to discharge the molten metal contained in the interior cavity in a direction toward a location where one casting roll of a pair of casting rolls engages a side dam of the twin roll caster. 
     
     
         3 . The uniform distribution nozzle of  claim 2 , where each end portion includes an end cavity extending outwardly away from the interior cavity in a direction of the body length, each end cavity adapted to receive molten metal through the at least one of the plurality of metering nozzles of the top member. 
     
     
         4 . The uniform distribution nozzle of  claim 2 , where each end portion includes an end cavity extending outwardly from the interior cavity in a direction of the body length, each end cavity open to the interior cavity at a top side of a raised section separating the interior cavity and end cavity. 
     
     
         5 . The uniform distribution nozzle of  claim 3 , where the length of the body is configured to provide a gap between each end portion and an adjacent side dam of the twin roll caster when arranged within the twin roll caster during casting. 
     
     
         6 . The uniform distribution nozzle of  claim 1  further including one or more gas ports extending through the uniform distribution nozzle and into the interior cavity, the one or more gas ports being arranged above an intended maximum head height location of the interior molten metal pool during casting operations. 
     
     
         7 . The uniform distribution nozzle of  claim 1 , where the top member is unitary with the body. 
     
     
         8 . The uniform distribution nozzle of  claim 1 , where the uniform distribution nozzle is configured to maintain an average head height of the interior molten metal pool within the interior cavity that is equal to or greater than 15 mm. 
     
     
         9 . A twin roll caster for continuously casting metal strip comprising:
 a pair of casting rolls laterally positioned to form a nip between them and side dams to form a molten metal pool supported by the pair of casting rolls between a pair of opposing side dams and adapted to counter rotate to form shells on the pair casting rolls brought together at the nip to cast metal strip downwardly from the nip;   a uniform distribution nozzle adapted to extend along and above the pair of casting rolls and to deliver metal from the uniform distribution nozzle to a location above the pair of casting rolls to form a casting pool of molten metal supported by the pair of casting rolls, the uniform distribution nozzle comprising: a unitary body formed of refractory and having a length configured to extend along a length of the casting pool in an axial direction of the pair of casting rolls, the body length extending at least 90% of a casting pool length; a top member arranged along a top side of the body and including a plurality of molten metal metering nozzles spaced apart along the length of the body; and, an interior cavity arranged within the body and below the top member, the interior cavity having a height extending from the top member to a bottom of the body, the body further including a plurality of outlet ports arranged below the top member and extending from the interior cavity to an exterior of the uniform distribution nozzle, where the interior cavity is configured to receive molten metal from the plurality of metering nozzles to form an interior molten metal pool and discharge the molten metal from the uniform distribution nozzle through the plurality of outlet ports and into the casting pool during casting; and,   a metal delivery system adapted to introduce molten metal through the uniform distribution nozzle downwardly converging toward the nip.   
     
     
         10 . The caster of  claim 9 , where the body of the uniform distribution nozzle further includes a pair of end portions, each end portion located at one end of a pair of opposing ends of the body length, each end portion including at least a pair of triple point outlet ports extending from the interior cavity and to the exterior of the delivery nozzle at a location above an intended height of the casting pool, each triple point outlet port is configured to discharge the molten metal contained in the interior cavity in a direction toward a location where one casting roll of the pair of casting rolls engages a side dam of the twin roll caster. 
     
     
         11 . The caster of  claim 10 , where each end portion of the uniform distribution nozzle includes an end cavity extending outwardly away from the interior cavity in a direction of the body length, each end cavity adapted to receive molten metal through the plurality of metering nozzles of the top member. 
     
     
         12 . The caster of  claim 11 , where the top member of the uniform distribution nozzle is arranged within a molten metal storage cavity of a storage vessel. 
     
     
         13 . The caster of  claim 12 , where the storage vessel is a transition piece arranged between the uniform distribution nozzle and a tundish. 
     
     
         14 . The caster of  claim 9  further including one or more gas ports extending through the uniform distribution nozzle and into the interior cavity, the one or more gas ports being arranged above an intended maximum head height location of the interior molten metal pool during casting operations. 
     
     
         15 . A method of casting metal strip comprising:
 providing a pair of casting rolls laterally disposed to form a nip between them, and adapted to support a casting pool of molten metal to be cast, with a pair of opposing side dams positioned adjacent end portions of the pair of casting rolls to confine the casting pool laterally;   providing a uniform distribution nozzle adapted to extend along and above the pair of casting rolls and to deliver metal from the uniform distribution nozzle to a location above the pair of casting rolls to form the casting pool of molten metal supported by the pair of casting rolls, the uniform distribution nozzle comprising: a unitary body formed of refractory and having a length configured to extend along a length of the casting pool in an axial direction of the pair of casting rolls, the body length extending at least 90% of a casting pool length; a top member arranged along a top side of the body and including a plurality of molten metal metering nozzles spaced apart along the length of the body; and, an interior cavity arranged within the body and below the top member, the interior cavity having a height extending from the top member to a bottom of the body, the body further including a plurality of outlet ports arranged below the top member and extending from the interior cavity to an exterior of the uniform distribution nozzle, where the interior cavity is configured to receive molten metal from the plurality of metering nozzles to form an interior molten metal pool and discharge the molten metal from the uniform distribution nozzle through the plurality of outlet ports and into the casting pool during casting; and,   delivering molten metal through the uniform distribution nozzle and to the casting pool, such that molten metal is caused to flow from the plurality of metering nozzles of the uniform distribution nozzle and into the interior molten metal pool arranged in the interior cavity, and from the interior molten metal pool, through the plurality of outlet ports, and into the casting pool; and   counter rotating the pair of casting rolls to deliver cast strip downwardly from the nip as casting proceeds.   
     
     
         16 . The method of  claim 15 , where the body of the uniform distribution nozzle further includes a pair of end portions, each end portion located at one end of a pair of opposing ends of the body length, each end portion including at least a pair of triple point outlet ports extending from the interior cavity and to the exterior of the delivery nozzle at a location above an intended height of the casting pool, each triple point outlet port is configured to discharge the molten metal contained in the interior cavity in a direction toward a location where one casting roll of the pair of casting rolls engages a side dam of the twin roll caster, the method further including discharging molten metal from each pair of triple point ports in a direction toward and in the vicinity of the location where one casting roll of the pair of casting rolls engages the side dam of the twin roll caster. 
     
     
         17 . The method of  claim 15  further including one or more gas ports extending through the uniform distribution nozzle and into the interior cavity, the one or more gas ports being arranged above an intended maximum head height location of the interior molten metal pool during casting operations, where the method further includes:
 passing a flow of gas through the one or more gas ports. 
 
     
     
         18 . The method of  claim 17 , where in passing the flow of gas through the one or more gas ports, a gas substantially insoluble within the molten metal is passed through the one or more gas ports, the molten metal forming steel. 
     
     
         19 . The method of  claim 18 , where the gas is inert. 
     
     
         20 . The method of  claim 18 , where the gas is argon.