CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to, and the benefit of, U.S. provisional application no. 62/777,055, filed December 7, 2018 with the U.S. Patent Office, which is hereby incorporated by reference.

BACKGROUND

Field

[0002] Embodiments of this disclosure relate generally to desulfurization lances for desulfurizing molten metal, such as iron, for the making of steel.

Description of the Related Art

[0003] It is well known that sulfur is an undesirable element in the production of steel. Removal of sulfur from hot metal, such a molten iron, is referred to as desulfurization. Desulfurization is commonly performed by injecting of one or more reagents into a mixture of molten metal to remove sulfur present in the mixture. This removal of sulfur results in the formation of slag. In certain instances, desulfurization consists of pneumatic injection of fine grained desulfurization reagent(s) into hot metal with high dosing precision via a dispensing vessel and a refractory lined lance. For example, the molten metal may be contained in a ladle, such as refractory ladle or a ladle within a torpedo car, with the lance being inserted into the molten metal with the reagent(s) being discharged from a submerged end of the lance. In the lance, the reagent(s) is/are mixed with a carrier gas, which together are injected into the molten metal. Common reagents include calcium carbide, or a combination of lime and magnesium or of lime, calcium carbide, and magnesium. Common carrier gases include nitrogen or any inert gas. This process is commonly referred to as a dip lance process, which has been deemed a highly economical, effective, and reliable method of desulfurization. The reagent(s) in the injection line of the lance is/are under dense flow conditions to maximize reagent delivery yet optimized to reduce abrasive wear of injection lines. The lance injects the reagent(s) at a depth within the molten metal, which causes an intimate mixing of the desulfurization reagent within the hot metal. It is appreciated that the desulfurization reagents can be injected singly, simultaneously, or with a time lag. Each such process variation is termed mono-injection, co-injection, or multi-injection respectively. The output end of the lance has exit ports associated with a manifold, where design and quantity of exit ports can influence the effectiveness of desulfurization. It has become apparent, however, that there is a desire to improve the effectiveness of desulfurization by improving the reagent outlet design.

SUMMARY

[0004] Embodiments of the disclosure include a manifold (also interchangeably referred to as a distributor) and a desulfurization lance incorporating such manifold or the features provided therein.

[0005] In particular embodiments, a manifold for use in a desulfurization lance in the manufacture of steel includes a body extending longitudinally from a first end to a second end and having a central longitudinal axis located centrally within the body and extending longitudinally from the first end and to the second end. The first end includes an inlet adapted to fluidly connect with a carrier conduit of the lance to receive one or more reagents with a carrier gas. The second end includes a plurality of outlets for delivering the one or more reagents with a carrier gas into a pool of molten metal retained within a refractory ladle for desulfurization of the molten metal. The manifold further includes a plurality of conduits arranged between the first and second ends of the manifold. Each conduit, which may form a tube, pipe, or more generally an elongate hollow or cavity formed within a surrounding structure, has an inner passage in fluid communication with the manifold inlet and one of the plurality of manifold outlets. Stated differently, it can be said that the manifold includes a plurality of passages arranged between the first and second ends of the manifold. Each inner passage (which forms one of the“plurality of passages”) extends lengthwise between the inlet and one of the plurality of manifold outlets in a direction away from the body central axis as each conduit (which forms one of the“plurality of passages”) extends from the first end and to the second end of the manifold. Each inner passage (or more simply“passage”) has a cross-sectional area that varies as each extends from the first end to the second end of the manifold.

[0006] In certain instances, each conduit (or, each“passage”) has a conduit inlet (also referred to as a“passage inlet” corresponding to one of the plurality of passages) located at the manifold inlet and a conduit outlet (also referred to as a“passage outlet” corresponding to one of the plurality of passages) arranged at an opposing end of the conduit (or, of each “passage”), where the cross-sectional area of each conduit (or“passage”) at the conduit inlet (or“passage inlet”) is greater than a cross-sectional area of the conduit (or“passage”) at the conduit outlet (or“passage outlet”). Optionally, a sum of the inlet cross-sectional areas for the plurality of conduits (or“plurality of passages”) is more (greater) than a sum of the outlet cross-sectional areas for the plurality of conduits (or “plurality of passages”). Other relational associations between the sums for the inlet and outlet cross-sectional areas are possible.

[0007] Optionally, a partition is arranged between each of the plurality of conduits (or “plurality of passages”) at an inlet end of each conduit (or“passage”), the partition having a terminal end forming a blade facing the manifold inlet. Each partition may be arranged substantially at the manifold inlet, or in close relation, or otherwise spaced apart from the manifold inlet.

[0008] In extending in a direction away from the body central axis as each conduit (“passage”) extends from the first end and to the second end, in certain instances, a longitudinal central axis of each conduit (or“passage”) is biased from the body central axis by an angle greater than zero degrees and less than 90 degrees, in absolute value, or by an angle equal to or less than 18 degrees or of substantially 1 to 10 degrees, in absolute value. Other angles may be employed in other instances.

[0009] In certain instances the variable cross-sectional area tapers from the first end and to the second end. In doing so, the variable cross-sectional area may taper constantly (consistently) or intermittently from the first end and to the second end. It is also appreciated that when tapering, the variable cross-sectional area may decrease from the first end and to the second end.

[0010] Particular embodiments comprise a desulfurization lance for desulfurizing molten metal in the manufacture of steel. The lance includes a carrier conduit extending longitudinally from a first end and to a second end, the carrier conduit configured to discharge one or more reagents with a carrier gas. The lance also includes a manifold in accordance with any embodiment or variation thereof contemplated herein, or, the features described in any such manifold.

[0011] Particular embodiments comprise a method of using a desulfurization lance. Such methods include providing a desulfurization lance for desulfurizing molten metal in the manufacture of steel, the lance comprising any contemplated herein. The method further includes arranging the second end of the desulfurization lance within a pool of molten metal retained in an internal cavity of a ladle, the internal cavity having a depth and a transverse extent. The method further includes discharging the one or more reagents from the lance and into the pool of molten metal. In certain instances, the lance is substantially centered across a transverse extent of the internal cavity. Optionally, in arranging the desulfurization lance within the ladle, the lance is spaced 6 to 18 inches above a floor of the internal cavity. Other distances may be employed in other variations. It is appreciated that the ladle may be substantially filled to a rated capacity with molten metal, or to a level less than the rated capacity.

[0012] The foregoing and other objects, features, and advantages will be apparent from the following more detailed descriptions of particular embodiments, as illustrated in the accompanying drawings wherein like reference numbers represent like parts of particular embodiments. Since a conduit defines a corresponding inner passage, more generally, it can be said that a plurality of passages are present in the manifold, and as such, herein and hereafter, a“plurality of passages” can be used interchangeably with a“plurality of conduits” and a“passage” can be used interchangeably with a“conduit” of the plurality of conduits as well as any of the“inner passages” formed by any of the plurality of conduits, with the exception of the when each of the plurality of conduits are described as having inner passages. In instances herein where the manifold is described as including a plurality of conduits arranged between the first and second ends, each conduit having an inner passage in fluid communication with the manifold inlet and one of the plurality of manifold outlets, the manifold can also be more generally described as including a plurality of passages arranged between the first and second ends, each passage being in fluid communication with the manifold inlet and one of the plurality of manifold outlets. Also, herein and hereafter, a “passage inlet” may be used interchangeably with a“conduit inlet” and a“passage outlet” may be used interchangeably with a“conduit outlet”.

DETAILED DESCRIPTION OF THE DRAWINGS

[0013] FIG. 1 is a side elevational view of a desulfurization lance in accordance with an exemplary embodiment of the disclosure;

[0014] FIG. 2 is an enlarged view of area 2 of FIG. 1 showing a discharge end of the desulfurization lance;

[0015] FIG. 3 is a manifold in accordance with an exemplary embodiment of the disclosure;

[0016] FIG. 4 is a top view of the manifold of FIG. 3;

[0017] FIG. 5 is a bottom view of the manifold of FIG. 3; [0018] FIG. 6 is a side view of the manifold of FIG. 3;

[0019] FIG. 7A is a top view of a manifold showing the inlet portioned for fluid communication with three (3) manifold conduits, in accordance with another exemplary embodiment;

[0020] FIG. 7B is a top view of a manifold showing the inlet portioned for fluid communication with four (4) manifold conduits, in accordance with another exemplary embodiment;

[0021] FIG. 8 is a side elevational view showing the placement of a desulfurization lance arranged substantially centrally within a refractory ladle, where the lance is arranged substantially midway across a width of the internal molten metal retention cavity;

[0022] FIG. 9 is a top view of the desulfurization lance centrally arranged within the refractory ladle shown in FIG. 8, where the lance is shown substantially centered in the circular cross-section of the internal molten metal retention cavity;

[0023] FIG. 10 shows comparative CFD (computational fluid dynamics) velocity flow trajectory model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle;

[0024] FIG. 11 shows comparative CFD velocity flow contour model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0025] FIG. 12 shows comparative CFD velocity flow contour model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0026] FIG. 13 shows comparative CFD 3 -dimensional velocity contour model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle, the results being shown along parallel planes extending transversely and arranged at different heights within the ladle;

[0027] FIG. 14 shows comparative CFD thermal profile model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0028] FIG. 15 shows comparative CFD 3-dimensional thermal contour model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle, the results being shown along parallel planes extending transversely and arranged at different heights within the ladle;

[0029] FIG. 16 shows comparative CFD 3 -dimensional thermal surface contour model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle, the results being shown along the interior cavity surfaces of an associated ladle;

[0030] FIG. 17 shows comparative CFD velocity flow trajectory model results for two lances operating under the same conditions in a ladle, a first having a pair of constant cross-sectional area manifold conduits (where the cross-sectional shape may change but the area does not notably change) and a second having a pair of contracting manifold conduits, where the manifold inlet of the first lance has an inside diameter of 0.75” and the second lance having manifold inlet inside diameter of 1.0”;

[0031] FIG. 18 shows comparative CFD velocity flow contour model results for the two lances operating under the same conditions in a ladle as described in association with FIG. 17, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0032] FIG. 19 shows comparative CFD velocity flow contour model results for the two lances operating under the same conditions in a ladle as described in association with FIG. 17, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0033] FIG. 20 shows comparative CFD thermal profile model results for the two lances operating under the same conditions in a ladle as described in association with FIG. 17, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0034] FIG. 21 shows comparative CFD thermal profile model results for the two lances operating under the same conditions in a ladle as described in association with FIG. 17, the results being shown along a pair of perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle;

[0035] FIG. 22 shows comparative CFD 3 -dimensional thermal surface contour model results for the two lances operating under the same conditions in a ladle as described in association with FIG. 17, the results being shown along the interior cavity surfaces of an associated ladle; and, [0036] FIGS. 23-35 are each a grayscale reproduction of corresponding color FIGS. 10-22, where FIGS. 23-35 are arranged in the same order as FIGS. 10-22, and where symbols have been included in each FIG. 10-35 to the left of a scaled legend representing a stated range of measurements for a particular parameter shown in each corresponding figure, where each color or gray scale shade represents a range of values for the particular parameter shown in color or gray scale shade, where both color and gray scale versions have been provided due to the difficulties in depicting the contents otherwise.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0037] Embodiments of the present disclosure include a manifold for a desulfurization lance used in the desulfurization of molten metal, such as iron, in the manufacturing of steel. The molten metal may be retained as a pool in any vessel, such as a refractory ladle or torpedo car, for example. The manifold is also referred to synonymously as a distributor. It is appreciated that this manifold may form a portion of the lance or a component thereof. Other embodiments include a lance incorporating the manifold and a method of using the lance with manifold to desulfurize molten metal.

[0038] The manifolds described herein have been developed to improve the injection of reagents into a molten metal pool and the resulting flow within the molten metal pool. The improved pattern of injection results in the following improvements:

(1) attaining a more uniform distribution of reagents in all directions for a given

period of time;

(2) attaining a maximum distribution of reagents in a shorter period of time;

(3) more effectively mixing the reagents with the molten metal in the shortest period of time to minimize reagent consumption; and,

(4) reducing the period of time required for desulfurization, which results in the

reduced consumption of desulfurization reagents.

[0039] In particular embodiments, a manifold for use in a desulfurization lance includes a body extending longitudinally, that is, lengthwise, from a first end to a second end. Each end forms a terminal end of the manifold. The body also includes a central longitudinal axis located centrally within the body and extending longitudinally, that is, lengthwise, from the first end and to the second end along the length of the body. This central axis can be said to be centrally located along a widthwise extent, that is, a transverse extent, of the body, where the width or transverse extent extends in a direction perpendicular to the body length. In being centrally located, in certain instances the central axis is located centrally along each of the first and second ends of the body. The body length can be said to extend in the direction of the lance length when the manifold is arranged within the lance, the central axis being arranged parallel with a central longitudinal axis of the lance, that which extends in the direction of the lance length.

[0040] When forming a separate component from the lance, it is appreciated that the body may form any desired shape configured to be received by the lance. For example, the body may be cylindrical or a rectangular prism in certain instances. The body may also be formed of any desired material suitable for its use within the lance. For example, the body may be formed of a metal, metal alloy, plastic, refractory mix or ceramic, or concrete. It is also appreciated that the body may be formed using any desired process, such as molding, machining, pressing, and/or casting.

[0041] The first end of the manifold includes an inlet adapted to fluidly connect with a carrier conduit to receive one or more reagents with a carrier gas. It is appreciated that the reagent and gas may be received under any known or desired conditions as appreciated by one of ordinary skill. For example, in certain instances, the reagent(s) is/are supplied at 68 to 70 psi (pounds per square inch) pressure (e.g., lime at 70 psi and magnesium at 68 psi, with the flow rate of magnesium being 30 lbs/minute and the flow rate of lime being 90 lbs/minute, each of which may vary in the allowable range of tolerance. The manifold inlet may be centrally located along the body, such as along the manifold central axis, or may otherwise be arranged non-centrally, for the purpose of aligning the inlet with a carrier conduit arranged within the lance for the purpose of receiving reagent(s) with a carrier gas for discharge into molten metal for desulfurization. Centrally aligned connotes that the center of the manifold inlet is centered across a transverse extent of the manifold or within 5% deviation thereof. It is appreciated that the carrier conduit may comprise any desired structure known to one of ordinary skill, such as a pipe or tube, for example. The second end of the manifold includes a plurality of outlets for delivering the one or more reagents with a carrier gas into a pool of molten metal retained within a refractory ladle for desulfurization of the molten metal. The inlet and outlets comprise any desired shape. For example, in certain instances, the inlet and outlets are circular.

[0042] The manifold further includes a plurality of conduits arranged between the first and second ends of the manifold, each conduit having an inner passage in fluid communication with the manifold inlet and one of the plurality of manifold outlets. Each conduit may form a tube, pipe, or more generally an elongate hollow or cavity formed within a surrounding structure to define an inner passage as described or contemplated herein. Each inner passage can be said, in certain instances, to extend lengthwise from the manifold inlet and to one of the plurality of manifold outlets in a direction away from the body central axis as each conduit extends from the first end and to the second end. In other words, the inner passages radiate (extend) outwardly in a widthwise direction of the manifold or body as each conduit extends towards the second end of the manifold body (or more generally, of the manifold). In doing so, each such conduit, or at least a terminal portion of each such conduit, is biased relative to a central longitudinal axis of the manifold body. In certain instances, the length of each inner passage extends along a linear path, such as is shown by example in the figures, although it is contemplated that the length of each inner passage may extend along a non linear path in other variations. It is also appreciated that any quantity of conduits may be arranged within the manifold, the plurality of conduits being equal in quantity to the quantity of outlets contained in the manifold. In certain instances, for example, the manifold includes 2, 3, or 4 conduits. Additional conduits are contemplated in other variations.

[0043] To improve the flow of reagent within the molten metal during desulfurization and thereby improve the efficiency and effectiveness of desulfurization, at least one inner passage of one of the conduits has a variable cross-sectional area that contracts (decreases) as each such inner passage (conduit) extends from the first end and to the second end, that is, from the inlet and to a corresponding outlet. By virtue of this contraction, the flow of reagent is characterized as having an increased or elevated velocity, sufficient to achieve improved reagent distribution within the molten metal. The cross-sectional area is measured in a consistent direction/orientation, such as by measuring the cross-section along a plane extending perpendicular to the body central axis. In certain instances each inner passage of each conduit of the plurality of conduits has a variable cross-sectional area that contracts (decreases) as each such inner passage extends from the inlet and to a corresponding outlet.

[0044] Each conduit within the manifold can be described as having a conduit inlet located at spaced apart or recessed from the manifold inlet and a conduit outlet arranged at an opposing end of the conduit. It is appreciated that each conduit outlet may be arranged at or recessed (spaced apart) from the second end of the manifold/manifold body. In lieu thereof, it is appreciated that each conduit outlet may be arranged along an exterior side of the manifold between the first and second ends. It follows that for each conduit having a variable and decreasing cross-sectional area, the cross-sectional area of the conduit inlet is greater than the cross-sectional area of the conduit outlet for the same corresponding conduit. As a result, when the cross-sectional area of the conduit inner passage decreases toward the manifold or inner passage outlet, the velocity of the reagent(s) with carrier gas increases. In certain instances when the cross-sectional area decreases, the sum of the conduit inlet cross-sectional areas for the plurality of conduits is greater than a sum of the outlet cross-sectional areas for the plurality of conduits. For each conduit, the conduit inlet is a passage inlet, while the conduit outlet is a passage outlet associated with the inner passage arranged within each such conduit. In combination, the conduit inlet cross-sectional areas taken together in sum for all manifold conduits substantially equal the cross-sectional area of the inner passage within the carrier conduit feeding into the manifold inlet. “Substantially” equal accounts for very small variances within manufacturing tolerances and the optional presence of a partition arranged between the manifold conduits, which when present only very slightly reduces the sum of conduit inlet cross-sectional areas relative to the inner passage cross-sectional area, such as when the terminal end thickness of the partition is 0.1 mm or less. It is noted that each conduit outlet forms an outlet of the manifold and of the lance, meaning, the reagent flow is discharged into the molten metal from each conduit outlet without first passing through any other structure, which may reduce the increased velocity achieved and/or alter the discharge direction of the reagent flow.

[0045] It is appreciated that the variable cross-sectional area for each inner passage in a corresponding conduit may vary such that the cross-sectional area decreases (contracts) as the inner passage and the void therein extends lengthwise toward the conduit outlet, that is, from a passage inlet and to a passage outlet. This decrease (contraction) is gradual or tapers in certain instances, where this gradual or tapering change occurs constantly and substantially the full length of the conduit. In other variations, the gradual or tapering occurs intermittently or constantly less than the substantial length of the conduit. In particular exemplary instances, each manifold conduit experiences a substantially 15% reduction per inch of length. For example, in one exemplary instance, a manifold conduit having a length of 3.57 inches (biased by 11.4 degrees over a 3.5 inch length of the manifold body) experiences a 54% reduction in cross-section from a conduit inlet to a conduit outlet, such as where the manifold conduit inlet has an inlet area of 0.44 square inches (e.g., where the manifold inlet has an inside diameter of substantially 1.05 inches that is divided into 2 conduits) and the manifold conduit outlet has an outlet area of 0.23 square inches (0.54 inch diameter). It is appreciated that the amount of reduction per inch of conduit length may range 10% to 20% reduction per inch (e.g., 36% to 71% over 3.57” long conduit), or otherwise as desired to achieve improved reagent mixture and distribution within a target volume of molten metal.

[0046] One or more partitions may optionally be arranged at, or in close proximity and recessed (spaced apart) from, the manifold inlet, or at another location between the manifold inlet and the second end of the manifold. In certain instances, the one or more partitions effectively partition the manifold inlet into the individual conduit passage inlets. In doing so, it can be said that the one or more partitions are arranged between each of the plurality of conduits at an inlet end of each conduit. While these partitions may from any shape, in certain instances, to reduce the likelihood of reagent build-up at the manifold inlet, any such partition forms a blade, where each partition has a terminal end facing the manifold inlet that forms the blade. In forming a blade, the partition at the terminal end has a thickness. For example, in certain instances, the terminal end thickness is 0.1 mm or less. In certain instances, the terminal end has a minimum thickness of 0.05 mm. It is appreciated that any partition may extend across the manifold inlet partially or fully along any linear or non-linear path. By example, when partitioning the manifold inlet into two conduit inlets, a single partition may extend across the manifold inlet. By further example, when partitioning the manifold inlet into three conduit inlets, two or three partitions may be employed. In yet another example, when partitioning the manifold inlet into four conduit inlets, two to four partitions may be employed, for example.

[0047] To further assist in the improvement in the flow of reagent within the molten metal during desulfurization, and to thereby improve the efficiency and effectiveness of desulfurization, the length of any manifold conduit may generally extend outwardly in a direction away from the central longitudinal axis of the manifold as the conduit extends towards the second end of the manifold. In other words, any manifold conduit may radiate (extend) outwardly away from the central longitudinal axis by extending both in a direction of the manifold body width and in a direction towards the second end of the manifold. This lengthwise extension may be linear or non-linear; however, by discharging reagent outwardly from each conduit outlet in a direction both towards the sides of the ladle side walls and downwardly towards the ladle bottom (that is, towards the internal cavity floor of the ladle), an improvement in flow and ultimately distribution can improve desulfurization. In particular instances, in extending in a direction away from the body central longitudinal axis as each conduit extends towards the second manifold end, a longitudinal central axis of each conduit is biased from the body central axis by an angle greater than zero degrees and less than 90 degrees, in absolute value. In particular embodiments, the angle defining this bias is, in absolute value, on average 18 degrees or less, substantially 1 degree to 10 degrees, or substantially 1 degree to 9.8 degrees. In certain instances, the angle is substantially 5 to 9 degrees or 8 to 9 degrees, on average and in absolute value. As noted previously, each conduit outlet forms a reagent flow outlet of the manifold and lance from which reagent flow is discharged directly into the molten metal at the bias angle herein described.

[0048] In particular embodiments, the desulfurization lance for desulfurizing molten metal includes one or more carrier gas inlets and one or more reagent inlets, each of the carrier gas and reagent inlets being in fluid communication with the carrier conduit. The reagent(s) and carrier gas may be mixed within the lance or prior to presentation to the manifold for injection into molten metal. There are a variety of different lance constructions known to which the one or more reagents with carrier gas are delivered to the manifold at the manifold inlet. For example, in certain instances the carrier conduit includes one or more reagent conduits. In such instances, the one or more carrier gas inlets are in fluid communication with a carrier gas cavity or a carrier gas conduit, each of the carrier gas cavity and conduit also having at least one outlet. At least a portion of the lance may be surrounded externally by a protective shell. In certain instances, a protective shell is arranged about a lower portion of the carrier conduit, the carrier conduit being located coaxially within the protective shell, which may form a tube or pipe. This protective shell may be formed of refractory material. In any such instance, the lance includes any manifold described or suggested previously or elsewhere herein. It is appreciated that in certain embodiments the lance remains stationary after being positioned within the ladle and the molten steel during desulfurization. In other instances, the lance rotates to stir or agitate the molten steel during desulfurization, which can further improve the efficiency and effectiveness of desulfurization relative to the stationary lance. Still, while a stationary lance may be less effective and efficient, a rotating lance requires additional mechanical complexities that may result in issues of reliability, as well as increased maintenance and operating costs.

[0049] As noted previously, embodiments of the disclosure include methods of using a desulfurization lance to conduct a desulfurization process on molten metal, such as iron, in the manufacture of steel. It is appreciated that any desulfurization lance having any manifold described or suggested above or elsewhere herein may be provided and employed in any such method. The lance with manifold are arranged at least partially within an internal cavity of a ladle. Therein, a discharge end of the desulfurization lance is arranged within a pool of molten metal contained within the internal cavity, the internal cavity having a depth and a transverse extent, which, in other words, forms a width. Once arranged within the molten metal, the methods include discharging the one or more reagents with carrier gas from the lance and into the pool of molten metal. In certain embodiments, the lance is substantially centered (that is, substantially centrally located) transversely within the internal cavity. Substantially centered means that the lance is within a 5% deviation from being perfectly centered transversely, that is, it is within a 5% deviation of each transverse dimension. In particular instances thereof, the lance is spaced 6” to 18” above a floor of the internal cavity. For example, this spacing above the floor may be employed when the ladle is a 200 ton ladle having a tapered internal cavity expanding in diameter from the floor to the top opening. It is appreciated that these stated spacing distances may be altered for other conditions, which may include using different ladle designs and shapes and filling the ladle more or less relative to an intended or rated ladle capacity. Substantially filling a ladle to its rated capacity means that the ladle is filled to the rated capacity in normal conditions. While in these embodiments the lance is transversely substantially centered within the molten metal vessel (ladle), it is appreciated that the lance may be arranged in an off-centered position in other variations. It is also appreciated that the lance and manifold may be employed in any sized ladle, such as a 120 to 300 ton ladle, which may or may not have a tapered internal cavity similar to that described in the 200 ton ladle above.

[0050] Certain exemplary embodiments are discussed below in association with the figures.

[0051] With reference to FIG. 1, a desulfurization lance 10 is shown for desulfurizing molten metal. The lance includes one or more carrier gas inlets and one or more reagent inlets, each of the carrier gas and reagent inlets being in fluid communication with the carrier conduit. Lance 10 generally forms an elongate structure having a length Lio extending from a first end 12 and to a second end 14. The second end 14 is also referred to as a discharge end. Discharge end 14 includes a manifold 20 for discharging reagent(s) with a carrier gas from the lance and into molten metal from one or more conduits arranged within the manifold. As noted previously, the reagent(s) and carrier gas may be mixed within the lance or prior to presentation to the manifold for injection into molten metal, and as such, there are a variety of different lance constructions known to one of ordinary skill. The lance is shown to have a lower portion be surrounded externally by a protective shell 16, a carrier conduit 18 being located coaxially within the protective shell 16, which may form a tube or pipe made of refractory material.

[0052] FIG. 2 provides an enlarged view of the lance discharge end 14 as shown in FIG. 1.

[0053] With reference now to FIGS. 3-6 a manifold 20 is shown in accordance with an exemplary embodiment. In particular, the manifold 20 includes a body 22 extending longitudinally, that is, lengthwise, from a first end EI22 to a second end E2 ₂₂ - A central longitudinal axis A22 is located centrally within the body and extends longitudinally, that is, lengthwise, from the first end EI22 and to the second end E222 along the length L22 of the body 22. This central longitudinal axis A22 can be said to be centrally located along a widthwise extent, that is, a transverse extent, of the body, where the width or transverse extent W22 extends in a direction perpendicular to the body length L22. The central longitudinal axis A22 is located centrally along each of the first and second ends EI22, E222 of the body 22, and is also referred to as the manifold central longitudinal axis. The first and second ends EI22, E222 of the body 22 are also referred to herein as first and second ends of the manifold 10, respectively. With reference back to FIGS. 1-2, the manifold body length L ₂ 2 extends in the direction of the lance length when the manifold is arranged within the lance 10, the central axis A22 being arranged parallel with a central longitudinal axis A10 of the lance, which extends in the direction of the lance length L10. In this exemplary embodiment, the body 22 forms a cylinder for receipt by a similarly shaped cavity within the desulfurization lance, although other shapes may be employed in other variations.

[0054] In the exemplary embodiment shown in FIGS. 3-6, manifold first end EI22 includes a manifold inlet I22 adapted to fluidly connect with a carrier conduit to receive one or more reagents with a carrier gas. Inlet I22 includes a recess 24 configured to receive a portion of the carrier conduit of the lance. While the recess 24 is cylindrical, in other variations other shapes may be employed. Inlet I22 is centrally located along the body 22 and central longitudinal axis A22 for the purpose of aligning the inlet with a carrier conduit arranged within the lance, although a non-central arrangement is possible in other variations. Second end E2 ₂₂ includes a plurality of outlets O22 for delivering the one or more reagents with a carrier gas. Outlets O22 also form conduit outlets in the embodiment shown. The inlet I22 and outlets O22 are circular, but may form other shapes in other variations.

[0055] With continued reference to FIGS. 3-6, manifold 20 further includes a plurality of conduits 28 arranged between the first and second ends EI22, E222 of the manifold or body, each conduit having an inner passage P ₂ s in fluid communication with the manifold inlet I ₂₂ and one of the plurality of manifold outlets Each conduit 28 may form a tube or pipe or the like, or more generally may form an elongate hollow or cavity formed within a surrounding structure to define an inner passage P ₂₈ as described or contemplated herein. Each inner passage P ₂₈ extends lengthwise from the inlet I ₂₂ and to one of the plurality of outlets O ₂₂ in a direction away from the body central axis A ₂₂ as each conduit extends from the first end EI ₂₂ and to the second end E2 ₂₂ · In other words, the inner passages radiate (extend) outwardly in a widthwise direction W ₂₂ as each extends towards the second end E2 ₂₂ . The length of each inner passage extends along a linear path, which can be represented by linear longitudinal central axis A ₂₈ for each manifold conduit 28. In the embodiment shown, two (2) conduits 28 are employed. By separate example, in FIG. 7A, three (3) conduits 28 are employed while in FIG. 7B four (4) conduits 28 are employed.

[0056] It is noted that the length L ₂₈ each manifold conduit 28 extends outwardly in a direction away from the central longitudinal axis A ₂₂ of the body 22 as each conduit 28 extends towards the second end E ₂₂ of the body 22. In other words, each manifold conduit 28 radiates (extends) outwardly away from the central longitudinal axis A ₂₂ by extending both in a direction of the manifold body width W ₂₂ and in a direction towards the second end E2 ₂₂ of the manifold. This lengthwise extension is linear, as reflected by the central longitudinal axis A ₂₈ of the conduit 28. This outward extension is also reflected by the longitudinal central axis A ₂₈ being biased from the body central longitudinal axis A ₂₂ by an angle Q that is greater than zero degrees but less than 90 degrees, in absolute value. In particular embodiments, angle Q is, in absolute value, on average 18 degrees or less (and greater than 0 degrees) or on average 1 degree to 10 degrees or on average 1 degree to 9.8 degrees.

[0057] Each conduit 28 within the manifold 20 has a conduit inlet I ₂₈ located at the manifold inlet I ₂₂ and a conduit outlet O ₂₈ arranged at an opposing end of the conduit 28. In the embodiment shown, the cross-sectional area of the conduit inlet I ₂ s is greater than the cross- sectional area of the conduit outlet O ₂₈ for the same corresponding conduit 28. As noted previously, the conduit inlet I ₂₈ is a passage inlet, while the conduit outlet O ₂₈ is a passage outlet.

[0058] In the exemplary embodiment shown in FIGS. 3-6, the inner passage P ₂₈ of each conduit 28 has a variable cross-sectional area that decreases as each extends in a direction from the first end EI ₂₂ to the second end E2 ₂₂ , that is, in a direction away from the inlet I ₂₂ and toward a corresponding outlet O ₂₂ . The cross-sectional area is measured along a plane PL _X extending perpendicular to the body central axis A ₂₂ . In the alternative, the cross- sectional area may be measured along a plane perpendicular to the central longitudinal axis A ₂₈ of each corresponding conduit 28. In this instance, each inner passage P _2S has a variable cross-sectional area as each such inner passage extends from the inlet I ₂₂ and to a corresponding outlet 0 ₂₂ . In the present embodiment shown in FIGS. 3-6, the variable cross- sectional area for each inner passage P _2S for each conduit 28 decreases as the inner passage extends lengthwise toward the conduit outlet 0 ₂ s, that is, from a passage inlet I _2S and to a passage outlet 0 ₂ s- This decrease is gradual, tapering constantly and continuously along the length of each inner passage P ₂ s. This is also true for each embodiment shown in FIGS. 7A and 7B. In other variations, the cross-sectional area of each conduit 28 and inner passage P _2S contracts (decreases) intermittently along the length of each conduit 28 between a corresponding conduit inlet I _2S and outlet 0 ₂ s- Further, in this embodiment, the sum of the conduit/passage inlet I _2S cross-sectional areas for the plurality of conduits 28 is greater than a sum of the conduit/passage outlet 0 ₂ s cross-sectional areas for the plurality of conduits 28.

[0059] With particular reference to the exemplary embodiment shown in FIGS. 3, 4, and 6, a partition 30 is shown extending across the manifold inlet I ₂₂ at an exit thereof between a pair of conduits 28. Partition 30 also divides the manifold inlet I ₂₂ into the two individual conduit passage inlets I _2S , thereby separating the pair of conduit inlets I ₂ s. It is appreciated that one or more additional partitions may arranged separate a plurality of conduits and their corresponding inlets I ₂ s. In extending at least partially or full across the manifold inlet I ₂₂ , a partition 30 may be arranged along the entrance or exit of manifold inlet I ₂₂ or across any portion of the cavity forming the manifold inlet I ₂₂ . In the embodiment shown, the partition 30 extends along the exit of manifold inlet I ₂₂ . In lieu of extending along the manifold inlet I ₂₂ , a partition 30 may be spaced apart from the manifold inlet I ₂₂ in the direction of second end E2 ₂₂ . In each instance, one or more partitions 30 separate two or more conduit inlets I ₂ s. In the embodiment shown, partition 30 forms a blade, where a terminal end facing the manifold inlet I ₂₂ forms the blade. In forming a blade, the partition 30 at the terminal end has a thickness of 0.1 mm or less. The partition also extends across the manifold inlet I ₂₂ fully along a linear path. With reference to another exemplary embodiment in FIG. 7, a plurality of partitions 30 are shown partitioning the manifold inlet into three conduit inlets I ₂ s.

[0060] With regard to arranging a desulfurization lance in a vessel containing a pool of molten metal, FIGS. 8 and 9 show a desulfurization lance 10 with a manifold 20 as described in the preceding figures, the lance 10 being arranged substantially centrally within a refractory ladle 40. In particular, the lance 10 is substantially centered across a transverse extent (that is, across width W ₄₂ ) of the ladle interior cavity 42. The interior cavity 42 is defined by one or more sidewalls 44 and a bottom (floor) 46, and is configured to retain molten metal therein. With particular reference to FIG. 8, the lance 10 is shown spaced apart from a bottom (floor) 46 of the lance internal cavity 42. In the embodiment shown, where the ladle is a 200 ton ladle as described previously above, the lance 10 at the discharge end 14 is spaced above the interior cavity bottom by a height H ranging from 6 to 18 inches to achieve a desired flow upon injection of reagent with a carrier gas from the lance manifold 20. Other heights may be employed to achieve other desired flows or to adapt to other conditions.

[0061] The benefits of employing the manifold described herein have been quantified using computational fluid dynamic (CFD) modeling under certain operating parameters using different lances having different discharge designs.

[0062] Initially, in FIGS. 10-16, two prior art lance designs were compared using CFD models, where all conditions remained the same except the manifold design for each. Specifically, the first lance employed a single, central discharge port (outlet) directed towards the internal cavity floor of the ladle while a second lance used a T-port discharge configuration, the T-port configuration comprising a pair of discharge ports (outlets) arranged 180 degrees opposite one another so to discharge reagent in a transverse direction against a sidewall of the ladle interior cavity.

[0063] FIG. 10 shows comparative CFD (computational fluid dynamics) velocity flow trajectory model results for a single, central discharge port lance and a T-port lance operating under the same conditions in a ladle. In comparing the two lances, the velocity flow trajectories evidence a direct impact along the interior cavity floor for the central port lance while the T-port lance is dividing the outward flow in half between the opposing outlets, each of which direct flow into opposing portions of the interior cavity sidewall. Therefore, the focused discharge forces are reduced using the T-port lance, as is any impact the discharge has on the ladle refractory linings. Additionally, the T-port lance provides improved mixing capabilities when compared to the central port lance due to the reduction in rebounding effects and spread volume of reagents in unit of time due to lower impact forces. This is evidenced by a visibly improved distribution of elevated velocity throughout the cavity. In FIGS. 11 and 12, perpendicular planes showing the velocity flow contours along each quadrant evidences an improved distribution of elevated velocity flow throughout the interior cavity for the T-port lance as compared to the central port lance. FIG. 13 further evidences an improved distribution of elevated velocity flow throughout the interior cavity for the T- port lance as compared to the central port lance when comparing parallel planes extending transversely and arranged at different heights within each ladle. In FIG. 14, perpendicular planes intersecting centrally within the ladle and extending vertically and transversely relative to the ladle show that a warmer and more homogenous thermal profile is achieved using a central port lance in lieu of a T-port lance. FIG. 14 shows better horizontal thermal stratification for central port and better perpendicular stratification for T-port. Comparison of thermal profiles overall shows that the central port lance creates better thermal homogeneity. With regard to the T-port lance, a reduction in thermal stratification and thermal vortexing effect is shown in FIG. 14 as compared to the central port lance, as is evidenced by the non- uniform arrangement of heat between the quadrants at different elevations, which enhances the mixing efficiency using the T-port lance. Thermal vortexing refers to the formation of a thermal vortex and the extent of such formation as evidenced by the presence of different temperatures or temperature gradients, where lower temperature molten metal becomes arranged elevationally lower relative to warmer molten metal and where a transverse temperature gradient is achieved. FIG. 15 further evidences the reduced stratification and thermal vortexing by showing reduced homogeneity annularly around each elevational plane, which results in improved mixing effectiveness. In FIG. 16, the T-port lance generates a more uniform thermal distribution along the surface of the ladle. Consistent therewith, it is noted that due to the division of flow into two outlets with the T-port lance, the resulting side wall impact is not noticeable. However, with reference to the central port lance, elevated heat is shown at the point of impact along the internal cavity floor.

[0064] A CFD comparison was then conducted between two different manifold designs each having a manifold inlet and a pair of conduits each extending radially outward while also extending away from the inlet and to an outlet to compare the effects of contraction. In a first manifold, the cross-section of the conduits, that is, of the conduit inner passages, remained substantially constant in cross-sectional area (although the cross-sectional shape changed) as each extended longitudinally from the inlet and to a corresponding outlet. In a second manifold, the cross-section of the conduits, that is, of the conduit inner passages, contracted (decreased) as each extended longitudinally from the inlet and to a corresponding outlet. The inlets for the first manifold (identified as“0.75 inch 80” in the figures) were smaller than the manifold conduit inlets for the second manifold (identified as“VORD” in the figures), while the manifold outlets remained the same size (0.75”) for each of the first and second manifolds. The manifold inlet for the first manifold was fed by a carrier conduit having a 0.75 inch inner diameter (forming an inner passage diameter) while the manifold inlet for the second manifold was fed by a carrier conduit having a 1.0 inch inner diameter (inner passage diameter). The conduit outlets for each of the first and second manifold measured 0.54 inches in diameter, and directed reagent directly into the molten metal, thereby operating as lance outlets. Otherwise, the manifolds were of the same height and width, and the outlets were of the same quantity, size, shape, and spacing. Also, the angle (0) by which by which each of the conduits were biased relative to a central longitudinal axis of the manifold body was substantially the same (approx. 11.4 degrees). Each of the conduits also extended lengthwise linearly for the same distance, and for a distance of 3.5 inches in the direction of the manifold length. In performing these CFD comparisons, the operating conditions (inputs) were the same for each manifold. For example, the reagants are supplied at 68 to 70 psi (pounds per square inch) pressure (e.g., lime at 70 psi and magnesium at 68 psi, with the flow rate of magnesium being 30 lbs/minute and the flow rate of lime being 90 lbs/minute). These are targeted figures and rates may vary in the allowable range of tolerance. With reference to FIG. 17, velocity flow trajectories are shown for both first manifold (“0.75 inch 80”) and second manifold (“VORD”), which are also referred to as first and second lances, respectively. As is observed, the flow trajectories for the second manifold fill a greater volume of the ladle than those of the first manifold. As a result, greater mixing efficiencies are achieved for the second manifold relative to the first manifold. FIGS. 18 and 19 show comparative CFD velocity flow contour model results, where the first manifold achieves elevationally higher velocity distribution than that of the second manifold. These results also show improved mixing efficiency for the second manifold relative to the first manifold due to the difference between different diameter of inlet conduits and the resulting difference in contraction. It is appreciated that the second manifold achieves a higher exit velocity than the first manifold due to the conduit contraction present in the second manifold conduits (which taper from a 1.0 inch inlet as compared to a 0.75 inch inlet for the first manifold). Upon comparing the thermal profiles in FIGS. 20 and 21, the second manifold achieves a more even thermal distribution, including extending higher elevationally than the first manifold. Stated differently, the first manifold provides molten metal having a greater thermal gradient/variation. As a result, the second manifold reduces thermal stratification and thermal vortexing relative to the first manifold. Finally, in comparing the thermal profile achieved by each manifold along the internal cavity ladle surfaces, FIG. 22 shows that the thermal profiles achieved are comparable. While the CFD results shown in FIGS. 17 to 22 establish performance differences between the first and second manifolds, with the second manifold having contracting improved mixing efficiencies over uniform area conduits and relative to the lances utilizing central port and T-port manifolds.

[0065] Based upon the foregoing, particular embodiments include the following (in addition to other embodiments described and contemplated herein):

1. A manifold for use in a desulfurization lance in the manufacture of steel, the

manifold comprising:

a body extending longitudinally from a first end to a second end and having a central longitudinal axis located centrally within the body and extending longitudinally from the first end and to the second end,

the first end including an inlet adapted to fluidly connect with a carrier conduit of the lance to receive one or more reagents with a carrier gas,

the second end including a plurality of outlets for delivering the one or more reagents with a carrier gas into a pool of molten metal retained within a refractory ladle for desulfurization of the molten metal;

a plurality of conduits arranged between the first and second ends of the manifold, each conduit having an inner passage in fluid communication with the manifold inlet and one of the plurality of manifold outlets, where each inner passage extends lengthwise between the inlet and one of the plurality of outlets in a direction away from the body central axis as each conduit extends from the first end and to the second end of the manifold body; and

each inner passage having a cross-sectional area that varies as each extends from the first end to the second end where each conduit of the plurality of conduits has a conduit inlet located at the manifold inlet and a conduit outlet arranged at an opposing end of the conduit, where the cross-sectional area of each conduit at the conduit inlet is greater than a cross-sectional area of the conduit at the conduit outlet.

2. The manifold of 1 above, where a sum of the inlet cross-sectional areas for the plurality of conduits is greater than a sum of the outlet cross-sectional areas for the plurality of conduits. 3. The manifold of 1 above, where a partition is arranged between each of the plurality of conduits at an inlet end of each conduit.

4. The manifold of 3 above, where the partition has a terminal end forming a blade facing the manifold inlet.

5. The manifold of 3 above, where the partition is arranged substantially at the

manifold inlet.

6. The manifold of 1 above, where in extending in a direction away from the body central axis as each conduit extends from the first end and to the second end, a longitudinal central axis of each conduit is biased from the body central axis by an angle greater than zero degrees and less than 90 degrees, in absolute value.

7. The manifold of 6 above, where the angle is equal to or less than 18 degrees on average, in absolute value.

8. The manifold of 7 above, where the angle is substantially 1 to 10 degrees on

average, in absolute value.

9. The manifold of 1 above, where the variable cross-sectional area tapers from the first end and to the second end.

10. The manifold of 9 above, where the variable cross-sectional area tapers constantly from the first end and to the second end.

11. The manifold of 10 above, where the variable cross-sectional area decreases from the first end and to the second end.

12. A desulfurization lance for desulfurizing molten metal in the manufacture of steel, the lance comprising:

a carrier conduit extending longitudinally from a first end and to a second end and configured to discharge one or more reagents with a carrier gas;

a manifold as recited in any one of 1 to 11 above.

13. A method of using a desulfurization lance comprising:

providing a desulfurization lance for desulfurizing molten metal in the manufacture of steel, the lance including:

a carrier conduit extending longitudinally from a first end and to a second end and configured to discharge one or more reagents with a carrier gas;

a manifold as recited in any one of 1 to 11 above; arranging the second end of the desulfurization lance within a pool of molten metal retained in an internal cavity of a ladle, the internal cavity having a depth and a transverse extent; and,

discharging the one or more reagents from the lance and into the pool of molten metal.

14. The method of 13 above, where the lance is substantially centered across a

transverse extent of the internal cavity.

15. The method of 14 above, where in arranging the desulfurization lance within the ladle, the lance is spaced 6 to 18 inches above a floor of the internal cavity.

16. The method of 15 above, where ladle is substantially filled to rated capacity with molten metal.

[0066] To the extent used, the terms “comprising,” “including,” and “having,” or any variation thereof, as used in the claims and/or specification herein, shall be considered as indicating an open group that may include other elements not specified. The terms“a,”“an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. The terms“at least one” and“one or more” are used interchangeably. The term“single” shall be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” are used when a specific number of things is intended. The terms“preferably,” “preferred,”“prefer,”“optionally,”“may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (i.e., not required) feature of the embodiments. Ranges that are described as being“between a and b” are inclusive of the values for“a” and“b” unless otherwise specified.

[0067] While various improvements have been described herein with reference to particular embodiments thereof, it shall be understood that such description is by way of illustration only and should not be construed as limiting the scope of any claimed invention. Accordingly, the scope and content of any claimed invention is to be defined only by the terms of the following claims, in the present form or as amended during prosecution or pursued in any continuation application. Furthermore, it is understood that the features of any specific embodiment discussed herein may be combined with one or more features of any one or more embodiments otherwise discussed or contemplated herein unless otherwise stated.