Continuous casting can be used in steelmaking to produce semi-finished steel shapes such as ingots, slabs, blooms, billets, etc. During a typical continuous casting process (10), as shown in
A typical continuous casting nozzle (20), or submerged entry nozzle (SEN), is shown in more detail in
As the sliding gate assembly (16) moves to an open position from a closed position to allow the liquid steel (2) to flow into the mold (18), the incoming turbulent steel jet (3) may flow near the wall of the bore (26) of the nozzle (20), as shown in
In some instances in the prior art, the flow paths (4) of the liquid steel (2) from the ports (24) of the nozzle (20) become uneven and biased such that the liquid steel (2) is directed in a downward direction toward a broad face (19) of the mold (18), as shown in
Moreover, such uneven flow paths (4) throughout the mold (18) may produce liquid mold powder entrainment and/or uneven heat transfer. These uneven flow paths (4) may be enhanced when the nozzle (20) starts to clog with clusters of foreign particles in the steel (2). The agglomeration and attachment of these particles at different zones of the body of the nozzle (20) may distort the initial internal geometry, and may thereby change the flow paths (4) in the mold (18). Accordingly, once the nozzle (20) is clogged to a predetermined amount, the nozzle (20) may need to be changed. An increase of nozzle (20) changes during a sequence due to clogging may reduce the quality of the steel (2) as the flow paths (4) in the mold (18) are changed during the time the new nozzle (20) reaches steady state again. Such uneven flow paths (4) may require the mold operator to manually feed mold powder given that the melting rate becomes different and unsteady from one side of the mold (18) to the other.
Accordingly, there is a need to provide a continuous casting nozzle that produces a more uniform flow path of liquid steel into a mold.
A deflector is provided at a bottom portion of a continuous casting nozzle to improve fluid flow of the liquid steel into a mold by redirecting the liquid steel toward a central portion of the bore of the nozzle. This may reduce the number of laminations by mold powder entrainment, nozzle clogging, nozzle changes, surface defects in the mold, scarfing practices on slabs, interruptions in the operation, and/or manually feeding mold powder. Accordingly, such a continuous casting nozzle may improve the quality of the molded steel and the efficiency of the continuous casting process, while reducing costs.
It is believed that the present invention will be better understood from the following description of certain examples taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements.
The drawings are not intended to be limiting in any way, and it is contemplated that various embodiments of the present disclosure may be carried out in a variety of other ways, including those not necessarily depicted in the drawings. The accompanying drawings incorporated in and forming a part of the specification illustrate several aspects of the present disclosure, and together with the descriptions serve to explain the principles and concepts of the present disclosure; it being understood, however, that the present disclosure is not limited to the precise arrangements shown.
The following description and embodiments of the present disclosure should not be used to limit the scope of the present disclosure. Other examples, features, aspects, embodiments, and advantages of the present disclosure will become apparent to those skilled in the art from the following description. As will be realized, the present disclosure may contemplate alternate embodiments than those exemplary embodiments specifically discussed herein without departing from the scope of the present disclosure. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not restrictive.
Referring to
In the illustrated embodiment, the bore (126) comprises a first pair of walls (121) and a second pair of side walls (122) such that each wall (121) of the first pair of walls (121) is transverse to each wall (122) in the second pair of side walls (122). The walls (121) of the first pair of walls (121) taper inward toward the longitudinal axis (A) in the lower portion (129) of the bore (126) from the shelf (123) to the closed end (128), as best seen in
These side walls (122) comprise the opposing ports (124) on each side wall (122). Each port (124) may be aligned to extend outwardly from the longitudinal axis (A) along a plane (C). Referring to
Accordingly, the deflector (120) may be positioned at a bottom portion of a continuous casting nozzle (20) and positioned within a mold (18) below the bath level of the liquid steel (2). Liquid steel (2) may thereby flow through the deflector (120), out of the ports (124), and into the mold (18). Referring to
The fillets (125) positioned above the ports (124) may provide a smooth transition of the liquid steel (2) from the vertical steel jet (3) flowing from the bore (126) to flow paths (4) of the liquid steel (2) exiting the ports (124). Such a smooth transition may reduce nozzle clogging. Further, the taper along the walls (121) in the deflector (120) to the bottom of the bore (126) may increase the momentum in the direction of the centerline of the well bottom to direct the steel jet (3). Accordingly, the larger shelf (123) and/or tapered walls (121) may detach and redirect the steel jet (3) centrally along the walls (121) transverse to the ports (124), while the smaller shelf (123) and/or substantially straight side walls (122) may detach and centrally redirect the steel jet (3) a smaller amount above the ports (124). This may allow the fillets (125) to transition the steel jet (3) out of the ports (124) along the plane (C) aligned with the ports (124) such that the flow paths (4) of the liquid steel (2) impinge the narrow faces (17) of the mold (18) instead of the broad faces (19). This redirection of the discharged liquid steel (2) may thereby prevent high asymmetrical flows throughout the volume of the mold (18) such that the flow paths (4) of the liquid steel (2) exiting the deflector (120) are more symmetrical, as shown in
As best seen in
For instance, another embodiment of a deflector (220) is shown in
The walls (221) of the bore (226) transverse to the side walls (222) are substantially parallel along the longitudinal axis (A), instead of being tapered as in the deflector (120) described above, in the lower portion (229) of the bore (226) from the sloped wall (223) to the closed end (228), as best seen in
The side walls (222) comprise the opposing ports (224), as shown in
Accordingly, the deflector (220) may be positioned at a bottom portion of a continuous casting nozzle (20) and positioned within a mold (18) below the bath level of the liquid steel (2). Liquid steel (2) may thereby flow through the deflector (220), out of the ports (224), and into the mold (18). The deflector (220) may redirect at least a portion of the steel jet (3) toward a center of the deflector (220) along the longitudinal axis (A) before the steel jet (3) exits the deflector (220) through the ports (224). For instance, the sloped wall (223) within the deflector (220) may provide a disruption in the flow of the steel jet (3) to detach at least a portion of the steel jet (3) from the wall (221) of the bore (226) to centrally redirect the steel jet (3). The substantially straight profile of the side walls (222) parallel to the ports (124) may prevent an abrupt separation of the liquid steel (2) from these side walls (222) of the bore (226). As the steel jet (3) reaches the closed end (228) of the bore (226), a swirl may be produced in the steel jet (3) that divides into two flow paths (4) in opposite directions when liquid steel (2) is discharged into the mold (18) from the two ports (224).
The fillets (225) positioned above the ports (224) may provide a smooth transition of the liquid steel (2) from the vertical steel jet (3) flowing from the bore (226) to flow paths (4) of the liquid steel (2) exiting the ports (224). Such a smooth transition may reduce nozzle clogging. Further, the smaller diameter between the walls (121) in the deflector (220) relative to the diameter between the side walls (222) may increase the momentum in the direction of the centerline of the well bottom to direct the steel jet (3). Accordingly, the sloped wall (223) and/or smaller diameter between the walls (221) may detach and redirect the steel jet (3) centrally along the walls (221) transverse to the ports (224), while the substantially straight side walls (122), without a sloped wall (223) and/or a wider diameter may detach and centrally redirect the steel jet (3) a smaller amount above the ports (224). This may allow the fillets (225) to transition the steel jet (3) out of the ports (224) such that the flow paths (4) of the liquid steel (2) are directed along the plane (C) defined by the ports (226) to impinge the narrow faces (17) of the mold (18) instead of the broad faces (19). This redirection of the discharged liquid steel (2) may thereby prevent high asymmetrical flows throughout the volume of the mold (18) such that the flow paths (4) of the liquid steel (2) exiting the deflector (220) are more symmetrical and/or increase the momentum of the upper loops of the flow paths (4) to provide a more desirable flow of the liquid steel (2) into the mold (18). Other suitable configurations for the deflector (220) will be apparent to one with ordinary skill in the art in view of the teachings herein.
In one embodiment, continuous casting nozzle may comprise a deflector at a bottom portion of the nozzle. The deflector may comprise a bore extending through the deflector from an open end to a closed end along a longitudinal axis of the deflector. The bore may comprise a first pair of walls and a second pair of walls transverse to the first pair of walls. A pair of ports may extend through the deflector from the bore to an outer surface of the deflector. A width of the bore between the first pair of walls may be substantially rapidly decreased between an upper portion of the bore and a lower portion of the bore. Each port of the pair of ports may be positioned on opposing walls of the second pair of walls. The pair of ports may be positioned proximally above the closed end of the bore. Each wall of the second pair of walls may comprise at least one fillet positioned above each port to form a rounded surface between each wall and each port. Each port of the pair of ports may extend along a plane substantially parallel with the first pair of walls, wherein each port of the pair of ports may be angled downward relative to the longitudinal axis of the deflector along the plane. Each wall of the first pair of walls may comprise a shelf between the upper portion and the lower portion tranvserse to the longitudinal axis such that each wall of the first pair of walls steps inward toward the longitudinal axis of the deflector. Each wall of the first pair of walls may taper inward toward the longitudinal axis from the shelf to the closed end of the bore. Each wall of the second pair of walls may comprise a shelf tranvserse to the longitudinal axis such that each wall of the second pair of walls steps inward toward the longitudinal axis of the deflector, wherein a thickness of the shelf between the second pair of walls may be smaller than a thickness of the shelf between the first pair of walls. Each wall of the first pair of walls may comprise an arcuate surface at the upper portion and a flat surface at the lower portion. Each wall of the first pair of walls may comprise a slope between the upper portion and the lower portion such that each wall of the first pair of walls slopes inward toward the longitudinal axis of the deflector. Each wall of the first pair of walls may be substantially parallel with the longitudinal axis of the deflector from the slope to the closed end of the bore. Each wall of the second pair of walls may comprise a uniform arcuate surface.
In another embodiment, a continuous casting nozzle may comprise a deflector at a bottom portion of the nozzle. The deflector may comprises a bore extending through the deflector from an open end to a closed end along a longitudinal axis of the deflector. A pair of ports may extend through the deflector from the bore to an outer surface of the deflector. A diameter of the bore may substantially rapidly decrease along the longitudinal axis above the pair of ports such that a portion of a flow of fluid through the deflector becomes detached from a surface of the bore to thereby redirect the flow of fluid toward the longitudinal axis prior to exiting through the pair of ports.
A method for directing a liquid into a continuous casting mold through a nozzle, wherein the nozzle comprises a bore extending through the nozzle from an open end to a closed end along a longitudinal axis and a pair of ports extending through the nozzle from the bore to an outer surface of the nozzle above the closed end, may comprise: positioning a bottom portion of the nozzle within the mold; flowing liquid into the open end of the bore such that a flow path of the liquid is offset from the longitudinal axis of the bore; redirecting the flow path of the liquid through the bore toward the longitudinal axis of the bore such that at least a portion of the flow path of the liquid is detached from a surface of the bore; and dispensing the liquid into the mold through the pair of ports. The nozzle may comprise at least one fillet having a rounded surface positioned above each port of the pair of ports to smoothly transition the flow path of the liquid from vertically along the longitudinal axis to outwardly through the pair of ports tranverse to the longitudinal axis. The pair of ports may be aligned along a plane such that a central portion of each port of the pair of ports extends along the plane, wherein the liquid is directed outwardly from the nozzle along the plane when the liquid is dispensed into the mold through the pair of ports. The liquid may be directed to a narrow face of the mold. The flow path of the liquid dispensed through a first port of the pair of ports may be substantially symmetrical with the flow path of the liquid dispensed through a second port of the pair of ports. A mainstream of the flow path of the liquid dispensed from each port of the pair of ports may be directed outwardly downward from the nozzle and a secondary stream of the flow path of the liquid dispensed from each port of the pair of ports may be directed outwardly upward from the nozzle to form an upper loop. A diameter of the bore may be substantially rapidly decreased to detach at least a portion of the flow path of the liquid from a surface of the bore. The amount of liquid directed toward the longitudinal axis may be increased along the surfaces of the bore that are transverse to the surfaces of the bore comprising the pair of ports.
Having shown and described various embodiments of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Several of such potential modifications have been mentioned, and others will be apparent to those skilled in the art. For instance, the examples, embodiments, geometrics, materials, dimensions, ratios, steps, and the like discussed above are illustrative and are not required. Accordingly, the scope of the present invention should be considered in terms of any claims that may be presented and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.
This application claims priority to U.S. Provisional Application Ser. No. 62/425,800, entitled “Continuous Casting Nozzle Tapered Deflector Bore Design for Improved Fluid Flow,” filed on Nov. 23, 2016, the disclosure of which is incorporated by reference herein.
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Number | Date | Country | |
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