This application relates to the casting of metals, and, more particularly, to casting mold systems for casting systems.
A direct chill (DC) casting process is a semi-continuous process for producing solid metal ingots (e.g., aluminum alloy ingots) from liquid melt. In the DC casting process, liquid melt is initially cooled in a shallow bottomless mold whose cavity shape is based on the desired cross-section of the ingot. Initially a bottom block seals the mold cavity from the lower side. During the casting process, the liquid melt is poured from the upper side into the mold, and the bottom block is lowered into a curtain of coolant (e.g., cooling water), which further cools the metal in the periphery, resulting in a solidified shell that holds a liquid sump. The downward motion of the bottom block follows a specified casting speed profile. After the initial ramp-up of the casting speed, the casting progresses in steady state during which the thermal and solidification profiles do not vary with time.
In steady state casting, there are two distinct cooling regions—a primary cooling region and a secondary cooling region. The initial cooling at the periphery of the ingot in the mold is known as the primary region. In the primary cooling region, the heat extraction rate from the melt is very high at the first point of contact because the melt is in direct contact with the water cooled mold. But, after the formation of this initially solidified shell, an air gap is formed at the mold/ingot interface due to solidification shrinkage. This air gap leads to a drop in the heat transfer rate within the mold region, and partial re-melting of the solidified shell may result in the primary cooling region due to this drop in the heat transfer rate.
After emerging from the mold, the solidified ingot goes into a secondary cooling region where it is further cooled by direct coolant impingement on the periphery of the ingot. In the secondary cooling region, cooling of the ingot is due to boiling heat transfer as the coolant is in direct contact with the hot ingot surface. Based on the cooling conditions, most of cooling (95% of total) is achieved by the secondary cooling.
Embodiments covered by this patent are defined by the claims below, not this summary. This summary is a high-level overview of various embodiments and introduces some of the concepts that are further described in the Detailed Description section below. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used in isolation to determine the scope of the claimed subject matter. The subject matter should be understood by reference to appropriate portions of the entire specification of this patent, any or all drawings, and each claim.
According to certain embodiments, a direct chill casting mold system includes a mold and a coolant bar. The mold defines a casting cavity having a casting axis. The coolant bar includes a plurality of nozzles and is configured to dispense a coolant via the plurality of nozzles onto a periphery of a metal product after the metal product has passed through the mold. In various aspects, the coolant bar is movable relative to the casting axis (e.g., linearly, rotationally, etc.).
According to some embodiments, a direct chill casting mold system includes a mold defining a casting cavity having a casting axis. The direct chill casting mold system also includes a coolant bar having a plurality of nozzles. The coolant bar is configured to dispense a coolant via the plurality of nozzles onto a periphery of a metal product after the metal product has passed through the mold. In certain embodiments, an angle of at least one nozzle of the plurality of nozzles is adjustable relative to the casting axis.
According to various embodiments, a direct chill casting mold system includes a mold, a first coolant bar, and a second coolant bar. The mold defines a casting cavity having a casting axis. The first coolant bar is downstream from the mold and includes a plurality of first nozzles. The first coolant bar is configured to dispense a coolant via the plurality of first nozzles onto a periphery of a metal product after the metal product has passed through the mold. The second coolant bar is downstream from the mold and includes a plurality of second nozzles. The second coolant bar is configured to dispense the coolant via the plurality of second nozzles onto the periphery of the metal product after the metal product has passed through the mold. In certain embodiments, the first coolant bar is fixed in a direction substantially perpendicular to the casting axis, and the second coolant bar is adjustable in the direction substantially perpendicular to the casting axis.
According to some embodiments, a direct chill casting mold system includes a mold and a coolant bar. The mold defines a casting cavity having a casting axis, and the mold is adjustable in the direction substantially perpendicular to the casting axis such that a dimension of the casting cavity in the direction substantially perpendicular to the casting axis is adjustable. The coolant bar includes a plurality of nozzles, and the coolant bar is configured to dispense a coolant via the plurality of nozzles onto a periphery of a metal product after the metal product has passed through the mold. In various aspects, the coolant bar is movable relative to the casting axis.
Various implementations described herein can include additional systems, methods, features, and advantages, which cannot necessarily be expressly disclosed herein but will be apparent to one of ordinary skill in the art upon examination of the following detailed description and accompanying drawings. It is intended that all such systems, methods, features, and advantages be included within the present disclosure and protected by the accompanying claims.
The specification makes reference to the following appended figures, in which use of like reference numerals in different figures is intended to illustrate like or analogous components.
The subject matter of embodiments of the present disclosure is described here with specificity to meet statutory requirements, but this description is not necessarily intended to limit the scope of the claims. The claimed subject matter may be embodied in other ways, may include different elements or steps, and may be used in conjunction with other existing or future technologies. This description should not be interpreted as implying any particular order or arrangement among or between various steps or elements except when the order of individual steps or arrangement of elements is explicitly described. Directional references such as “up,” “down,” “top,” “bottom,” “left,” “right,” “vertical,” “horizontal,” “lateral,” “longitudinal,” “front,” and “back,” among others, are intended to refer to the orientation as illustrated and described in the figure (or figures) to which the components and directions are referencing.
Described herein are casting mold systems for DC casting systems. While the casting mold systems described herein can be used with any metal, they may be especially useful with aluminum. The casting mold systems described herein each include a mold and at least one coolant bar.
The mold defines a casting cavity having a casting axis along which metal is moved as it is cast into a solidified product. In some cases, the mold may be internally cooled. In various examples, the mold is adjustable in one or more directions that are not parallel to the casting axis (hereinafter referred to as “adjustment directions”). In some examples, one or more adjustment directions are substantially perpendicular to the casting axis such that a dimension of the mold (and as such a dimension of the cast product) can be adjusted as desired. In one non-limiting example, in a vertical casting system, the mold may be adjustable in a horizontal direction.
The at least one coolant bar is downstream from the mold and includes a plurality of nozzles. During the casting process, the at least one coolant bar dispenses a coolant, including but not limited to water, via the plurality of nozzles onto a periphery of the metal product after the metal product has passed through the mold. In some embodiments, at least one of the plurality of nozzles is arranged at an oblique or otherwise non-zero (or non-parallel) angle relative to an axis of the coolant bar, although it need not be in other examples. In various examples, the axis of at least one of the plurality of nozzles may be adjustable relative to the axis of the coolant bar. As used herein, a “non-zero” angle is one that is not parallel with respect to a particular axis.
In various embodiments, the at least one coolant bar is movable relative to the casting axis. In various embodiments, the at least one coolant bar is adjustable linearly. Additionally or alternatively, the at least one coolant bar is pivotable or rotatable about a pivot axis that is not parallel to the casting axis. In certain cases, the pivot axis may be substantially perpendicular to the casting axis, although it need not be in other examples. In other examples, the at least one coolant bar may be movable relative to the casting axis via additional or alternative movements as desired. In certain embodiments, the at least one coolant bar is adjustable relative to the casting axis such that the axis of at least one of the plurality of nozzles is adjustable. In certain embodiments, the at least one coolant bar is movable between a start position, a transition position, and a run position. In some cases, in the start position, at least one nozzle of the plurality of nozzles is a first distance from the casting axis; in the transition position, the at least one nozzle of the plurality of nozzles is a second distance from the casting axis that is less than the first distance; and in the run position, the at least one nozzle of the plurality of nozzles is a third distance from the casting axis that is less than the second distance.
In some optional embodiments, more than one coolant bar, such as two coolant bars, may be utilized with casting mold system. The coolant bars may be arranged in various positions relative to each other and relative to the mold along the casting axis as desired (e.g., a coolant bar may be downstream from the mold and upstream from another coolant bar, may be downstream from the mold and another coolant bar, etc.). In certain embodiments with more than one coolant bar, at least one characteristic of one coolant bar optionally may be different from the other coolant bar. The at least one characteristic may include, but is not limited to, a number of nozzles, a pattern or arrangement of nozzles, a pressure at which the nozzles dispense the coolant, an angle of one or more of the nozzles relative to the axis of the coolant bar and/or the casting axis, movement relative to the casting axis, a surface profile facing the casting axis, combinations thereof, or other various characteristics as desired. As one non-limiting example, one coolant bar may be adjustable in the adjustment direction while the other coolant bar is fixed (not adjustable) in the adjustment direction. As another non-limiting example, one coolant bar may have a plurality of nozzles where each nozzle is arranged substantially perpendicular to the casting axis while the other coolant bar may have a plurality of nozzles where each nozzle is arranged at an oblique (or otherwise non-zero or non-parallel) angle relative to the casting axis. As a further non-limiting example, one coolant bar may have a substantially planar surface profile facing the casting axis while the other coolant bar may have a non-planar surface profile facing the casting axis. As another non-limiting example, one coolant bar may dispense the coolant at a first pressure, and the other coolant bar may dispense the coolant at a second pressure that is less than the first pressure. In one non-limiting example, one coolant bar may dispense the coolant with a gas and/or a supercritical fluid, while the other coolant bar may dispense just the coolant. Various other characteristics may be varied between two or more coolant bars as desired. In other embodiments, the characteristics need not be varied between two or more coolant bars.
The casting mold system described herein may provide improved cooling compared to existing mold systems, and the improved cooling may allow for the overall casting system to cast at a faster speed compared to existing casting systems without bleed-out and/or other defects in the ingot. The improved speed may allow for more metal to be cast in a given time period compared to existing casting systems and/or a shorter overall processing time for a given amount of metal compared to existing casting systems. In some examples, the casting mold system may optionally allow for faster casting speeds by providing two or more layers of coolant jets, which may ensure nucleate cooling by providing a better cooling capacity without a breakdown to film cooling. In some non-limiting examples, the casting mold system may allow for casting speeds of at least 60 mm/min., such as at least 70 mm/min., such as at least 75 mm/min., such as at least 80 mm/min, such as at least 85 mm/min.
The casting mold system described herein may also provide ingots having improved properties. As one non-limiting example, the casting mold system described herein may provide an ingot having an improved shape because the casting mold system can adjust the ingot's shape during the casting process as desired, which may reduce the amount of metal that would otherwise have to be scrapped in existing casting systems. In various examples, the casting mold system may also allow for multiple alloys to be cast on the same mold system because the shape of the mold can be adjusted as desired for each alloy. In certain examples, the casting mold system may also allow for ingots having different thicknesses to be cast with the same mold because the shape of the mold is adjustable as desired. In some embodiments, the casting mold system described herein may provide an ingot having a reduced shell zone or no detectable shell zone.
The mold 104, which may be internally cooled with a coolant such that the mold has cooled casting surfaces, provides initial primary cooling of the molten metal and peripherally confines and cools the molten metal to start formation of the region of solidified metal 112 of the ingot 110. The cooling metal moves out and away from the mold 104 through the mold outlet 108 along a casting axis 120. Jets 122 of coolant are directed from the mold 104 onto the outer surface of the ingot 110 as it emerges from the mold 104 in order to provide secondary cooling that thickens the region of solidified metal 112 and enhances the cooling process. The coolant may be a liquid, including but not limited to water.
Similar to the mold 104, the mold 204 includes a mold inlet 206 and a mold outlet 208 and defines a casting axis 220 along which metal may move during a casting process. While only a portion of the casting mold system 202 is illustrated in
In various examples, the mold 204 is adjustable in one or more adjustment directions 231.
In the embodiment of
The coolant bar 226 is at least partially downstream from the mold outlet 208 and is configured to dispense a coolant via a plurality of nozzles 236 onto a periphery of a metal product after the metal product has passed through the mold 204. In certain examples, the coolant bar 226 is positioned relative to the mold 204 such that at least one of the nozzles 236 is downstream from the mold 204. The coolant bar 226 may be constructed from various suitable materials as desired and may be a continuous structure or may include one or more bar sub-sections. The coolant bar 226 generally includes a top end 228 and a bottom end 230 opposite from the top end 228, and a bar axis 232 extends from the top end 228 to the bottom end 230. A face 234 of the coolant bar 226 includes the plurality of nozzles 236 that are configured to dispense a coolant onto a periphery of an ingot during casting. As best illustrated in
The arrangement of the nozzles 236 illustrated in
In various embodiments, the coolant bar 226 is movable relative to the casting axis 220 such that an angle and/or position of the nozzles 236 relative to the casting axis 220 can be adjusted as desired. When the coolant bar 226 includes one or more bar sections, one bar section may be movable independently from or in conjunction with another bar section. The coolant bar 226 may be adjustable via the same actuator mechanisms or different mechanisms as those used to control the mold 204. In certain embodiments, a controller or controllers may be provided to control the coolant bar. The controller or controllers may be various suitable computing devices as desired with a processor and/or a memory. In such embodiments, the controller or controllers may be operably connected to the actuator mechanisms or as otherwise desired such that the coolant bar is controlled as desired. In some embodiments, the controller or controllers may be operably connected to one or more sensors, and the controller may control the coolant bar based on information detected by the sensor(s). Additionally or alternatively, the controller may be used to control other aspects of the casting mold system. As some non-limiting examples, the controller may control a bottom block of the system, an angle of the coolant bar, a position of the coolant bar, a shape of the mold, a water flow rate, and/or as otherwise desired. In some embodiments, the coolant bar 226 is adjustable in the same adjustment direction(s) 231 as the mold 204, although it need not be in other examples. Additionally or alternatively to being linearly movable, the coolant bar 226 may have various other movement patterns as desired. In the embodiment of
During a casting process with the casting mold system 202, molten metal is introduced into the mold cavity 205 via the mold inlet 206. The casting surface 225 of the mold 204 provides primary cooling of the molten metal, and the metal exits the mold outlet 208 as a solidifying ingot. The coolant bar 226 provides secondary cooling by directing the coolant from the coolant chamber 240 to the nozzles 236 such that the nozzles 236 dispense the coolant on the periphery of the ingot. In various embodiments, and as discussed in greater detail below with respect to
In one aspect, and as best illustrated in
In various embodiments, the nozzles 236A are configured to dispense the coolant at a first pressure, and the nozzles 236B are configured to dispense the coolant at a second pressure that is different from the first pressure. In some non-limiting examples, the first pressure and the second pressure may be from about 250 psi to about 750 psi, although they may be outside of this range in other embodiments. In the example illustrated, the first pressure is greater than the second pressure such that the coolant bar 926A is a high pressure coolant bar and the coolant bar 9261B is a low pressure coolant bar. In various embodiments, one of the coolant bars (e.g., coolant bar 926A) is optionally in fluid communication with a gas and/or supercritical fluid, including but not limited to nitrogen or compressed air, and is configured to dispense the coolant with the gas and/or supercritical fluid. In various embodiments, one of the coolant bars is fixed relative to the casting axis 220, and the other coolant bar is movable relative to the casting axis 220. In the embodiment illustrated, the high pressure coolant bar 926A is fixed relative to the casting axis 220, and the low pressure coolant bar 926B is movable relative to the casting axis 220 (e.g., pivotably, in a plane perpendicular to the casting axis 220, etc.). In other embodiments, the high pressure coolant bar 926A may be movable and/or the low pressure coolant bar 926B may be fixed. Moreover, the arrangement of the high pressure coolant bar 926A and the low pressure coolant bar 926B relative to the mold 204 should not be considered limiting.
In certain embodiments, the multiple coolant bars 926A-B may help align nozzle positions appropriately relative to the casting axis 220 and relative to movement of the mold 204 relative to the casting axis 220. In some embodiments, the multiple coolant bars 926A-B may help maintain the distance between the high pressure nozzles 236A of the coolant bar 926A with the ingot. The coolant bar 926B with the low pressure nozzles 236B may minimize or reduce bounce-off of coolant from the ingot, and the movement of the low pressure coolant bar 926B relative to the ingot (linearly, rotationally, etc.) may allow for nozzle positions and/or angles to change relative to the ingot, thereby providing a desired heat transfer at various stages of casting.
A collection of exemplary embodiments are provided below, including at least some explicitly enumerated as “Illustrations” providing additional description of a variety of example embodiments in accordance with the concepts described herein. These illustrations are not meant to be mutually exclusive, exhaustive, or restrictive, and the disclosure not limited to these example illustrations but rather encompasses all possible modifications and variations within the scope of the issued claims and their equivalents.
Illustration 1. A direct chill casting mold system comprising: a mold defining a casting cavity comprising a casting axis, and a coolant bar comprising a plurality of nozzles, wherein the coolant bar is configured to dispense a coolant via the plurality of nozzles onto a periphery of a metal product after the metal product has passed through the mold, and wherein the coolant bar is movable relative to the casting axis.
Illustration 2. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the coolant bar comprises a coolant bar axis, wherein the plurality of nozzles comprises a first set of nozzles and a second set of nozzles, wherein each nozzle of the first set of nozzles extends at a first non-zero angle relative to the coolant bar axis, and wherein each nozzle of the second set of nozzles extends at a second non-zero angle relative to the coolant bar axis that is different from the first non-zero angle.
Illustration 3. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the coolant bar is movable between a start position, a transition position, and a run position, wherein: in the start position, at least one nozzle of the plurality of nozzles is a first distance from the casting axis; in the transition position, the at least one nozzle of the plurality of nozzles is a second distance from the casting axis that is less than the first distance; and in the run position, the at least one nozzle of the plurality of nozzles is a third distance from the casting axis that is less than the second distance.
Illustration 4. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the mold and the coolant bar are each movable relative to the casting axis in a direction substantially perpendicular to the casting axis.
Illustration 5. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the coolant bar is a first coolant bar and the plurality of nozzles are a first plurality of nozzles, wherein the direct chill casting mold system further comprises a second coolant bar comprising a second plurality of nozzles, and wherein the second coolant bar is between the mold and the first coolant bar along the casting axis.
Illustration 6. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the second coolant bar is fixed in the direction substantially perpendicular to the casting axis.
Illustration 7. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the first coolant bar is configured to dispense the coolant at a first pressure, wherein the second coolant bar is configured to dispense the coolant at a second pressure, and wherein the second pressure is greater than the first pressure.
Illustration 8. A direct chill casting mold system comprising: a mold defining a casting cavity comprising a casting axis; and a coolant bar comprising a plurality of nozzles, wherein the coolant bar is configured to dispense a coolant via the plurality of nozzles onto a periphery of a metal product after the metal product has passed through the mold, and wherein an angle of at least one nozzle of the plurality of nozzles is adjustable relative to the casting axis.
Illustration 9. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the mold is internally cooled.
Illustration 10. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the coolant bar comprises a coolant bar axis, wherein the plurality of nozzles comprises a first set of nozzles and a second set of nozzles, wherein each nozzle of the first set of nozzles extends at a first non-zero angle relative to the coolant bar axis, and wherein each nozzle of the second set of nozzles extends at a second non-zero angle relative to the coolant bar axis that is different from the first non-zero angle.
Illustration 11. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the coolant bar is pivotable about a pivot axis that is substantially perpendicular to the casting axis such that the angle of the at least one nozzle is adjustable relative to the casting axis.
Illustration 12. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the mold and the coolant bar are each movable relative to the casting axis in a direction substantially perpendicular to the casting axis such that a dimension of the casting cavity in the direction substantially perpendicular to the casting axis is adjustable.
Illustration 13. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the mold comprises a plurality of mold sections that are movable relative to each other, and wherein the coolant bar comprises a plurality of coolant bar sections that are movable relative to each other.
Illustration 14. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the coolant bar is a first coolant bar and the plurality of nozzles are a first plurality of nozzles, wherein the direct chill casting mold system further comprises a second coolant bar comprising a second plurality of nozzles, wherein the second coolant bar is configured to direct the coolant via the second plurality of nozzles onto the periphery of the metal product after the metal product has pass through the mold.
Illustration 15. A direct chill casting mold system comprising: a mold defining a casting cavity comprising a casting axis; a first coolant bar downstream from the mold, the first coolant bar comprising a plurality of first nozzles, wherein the first coolant bar is configured to dispense a coolant via the plurality of first nozzles onto a periphery of a metal product after the metal product has passed through the mold; and a second coolant bar downstream from the mold, the second coolant bar comprising a plurality of second nozzles, wherein the second coolant bar is configured to dispense the coolant via the plurality of second nozzles onto the periphery of the metal product after the metal product has passed through the mold, wherein the first coolant bar is fixed in a direction substantially perpendicular to the casting axis, and wherein the second coolant bar is adjustable in the direction substantially perpendicular to the casting axis.
Illustration 16. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the mold is adjustable in the direction substantially perpendicular to the casting axis such that a dimension of the casting cavity in the direction substantially perpendicular to the casting axis is adjustable.
Illustration 17. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the first coolant bar is configured to dispense the coolant at a first pressure, wherein the second coolant bar is configured to dispense the coolant at a second pressure that is less than the first pressure, and wherein the first coolant bar is between the mold and the second coolant bar.
Illustration 18. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the mold is internally cooled.
Illustration 19. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the plurality of second nozzles comprises a first set of second nozzles and a second set of second nozzles, wherein an angle of each one of the first set of second nozzles relative to the casting axis is different from an angle of each one of the second set of second nozzles relative to the casting axis.
Illustration 20. The direct chill casting mold system of any preceding or subsequent illustrations or combination of illustrations, wherein the second coolant bar is movable between a start position, a transition position, and a run position, wherein: in the start position, at least one nozzle of the plurality of second nozzles is a first distance from the casting axis; in the transition position, the at least one nozzle of the plurality of second nozzles is a second distance from the casting axis that is less than the first distance; and in the run position, the at least one nozzle of the plurality of second nozzles is a third distance from the casting axis that is less than the second distance.
Illustration 21. A direct chill casting mold system comprising: a mold defining a casting cavity comprising a casting axis, wherein the mold is adjustable in the direction substantially perpendicular to the casting axis such that a dimension of the casting cavity in the direction substantially perpendicular to the casting axis is adjustable; and a coolant bar comprising a plurality of nozzles, wherein the coolant bar is configured to dispense a coolant via the plurality of nozzles onto a periphery of a metal product after the metal product has passed through the mold, and wherein the coolant bar is movable relative to the casting axis.
The above-described aspects are merely possible examples of implementations, merely set forth for a clear understanding of the principles of the present disclosure. Many variations and modifications can be made to the above-described embodiment(s) without departing substantially from the spirit and principles of the present disclosure. All such modifications and variations are intended to be included herein within the scope of the present disclosure, and all possible claims to individual aspects or combinations of elements or steps are intended to be supported by the present disclosure. Moreover, although specific terms are employed herein, as well as in the claims that follow, they are used only in a generic and descriptive sense, and not for the purposes of limiting the described embodiments, nor the claims that follow.
This application claims priority to U.S. Provisional Application No. 62/705,915, filed on Jul. 22, 2020 and entitled DIRECT CHILL CASTING MOLD SYSTEM, and U.S. Provisional Application No. 62/200,798, filed Mar. 30, 2021 and entitled DIRECT CHILL CASTING MOLD SYSTEM, both of which are hereby incorporated by reference in their entireties.
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/US2021/042209 | 7/19/2021 | WO |
Number | Date | Country | |
---|---|---|---|
63200798 | Mar 2021 | US | |
62705915 | Jul 2020 | US |