WO2018122716A1

WO2018122716A1 - Manifolds for mixing fluids and related methods

Info

Publication number: WO2018122716A1
Application number: PCT/IB2017/058355
Authority: WO
Inventors: Mansour N. AL-HARBI; Abdulaziz Fahad AL-JUTAILI; Theeban M. AL-OTAIBI
Original assignee: Sabic Global Technologies B.V.
Priority date: 2016-12-28
Filing date: 2017-12-22
Publication date: 2018-07-05

Abstract

Manifolds and methods for using the same. Some manifolds (54) include a body (58) defining an inlet (62), an interior surface (102) extending between the inlet and a sidewall that defines at least a portion of a chamber (82), the chamber (82) being in fluid communication with and having a larger maximum transverse dimension than the inlet (62), and an outlet (66) in fluid communication with the chamber (82), one or more first conduits (118) in fluid communication with the chamber (82), each having an outlet (122) configured to provide a first fluid to the chamber (82), and one or more second conduits (138) in fluid communication with the chamber (82), each having an outlet (142) configured to provide a second fluid to the chamber (82), wherein the center of the outlet (142) of each of the second conduit(s) (138) is closer to the interior surface (102) of the body than is the center of the outlet (122) of each of the first conduit(s) (118).

Description

MANIFOLDS FOR MIXING FLUIDS AND RELATED METHODS

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority of US. Provisional Application No. 62/439,698, filed December 28, 2016, which is hereby incorporated by reference in its entirety.

BACKGROUND OF THE INVENTION

A. Field of Invention

[0002] The present invention relates generally to manifolds for mixing fluids, and more specifically, but not by way of limitation, to manifolds for use in enriching a reducing gas with a hydrocarbon fuel and an oxidant.

B. Description of Related Art

[0003] In direct-reduced iron (DRI) making operations, a DRI precursor (e.g., iron oxide pellets, lump ores, and/or the like) is contacted with a reducing gas to produce DRI. In some instances, it may be desirable to enrich the reducing gas with a hydrocarbon fuel and/or an oxidant prior to contacting the DRI precursor with the reducing gas. Due, at least in part, to sub-optimal flow characteristics, high temperatures, and/or the like within equipment for performing such enrichment, carbon deposition within the equipment may occur. Such carbon deposition can decrease the effectiveness of and/or increase the maintenance requirements of the equipment. SUMMARY OF THE INVENTION

[0004] Some embodiments of the present manifolds comprise: a body defining an inlet, an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being in fluid communication with and having a larger maximum transverse dimension than the inlet, and an outlet in fluid communication with the chamber, one or more first conduits in fluid communication with the chamber, each having an outlet configured to provide a first fluid to the chamber, and one or more second conduits in fluid communication with the chamber, each having an outlet configured to provide a second fluid to the chamber, wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits. In some embodiments, the inlet of the body, the chamber, and the outlet of the body are coaxial.

[0005] In some embodiments, a minimum distance between the center of one of the one or more second outlets that is closest to the interior surface and the interior surface is 95% or less of a minimum distance between the center of one of the one or more first outlets that is closest to the interior surface and the interior surface.

[0006] In some embodiments, the outlet of each of the one or more first conduits is defined by the sidewall of the body. In some embodiments, each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits. In some embodiments, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit.

[0007] In some embodiments, the sidewall is cylindrical. In some embodiments, at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle that is approximately 90°.

[0008] Some embodiments of the present methods comprise: directing a first fluid through an inlet and an outlet of a body of a manifold, the body including an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being disposed between and in fluid communication with the inlet and the outlet and having a larger maximum transverse dimension than the inlet, directing a second fluid into the chamber through an outlet of each of one or more first conduits, and directing a third fluid into the chamber through an outlet of each of one or more second conduits, wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits. [0009] In some embodiments, a minimum distance between the center of one of the one or more second outlets that is closest to the interior surface and the interior surface is 95% or less of a minimum distance between the center of one of the one or more first outlets that is closest to the interior surface and the interior surface.

[0010] In some embodiments, the outlet of each of the one or more first conduits is defined by the sidewall of the body. In some embodiments, at least one of the one or more second conduits is not surrounded by one of the one or more first conduits. In some embodiments, each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits. In some embodiments, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit.

[0011] In some embodiments, the sidewall is cylindrical. In some embodiments, at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle that is approximately 90°.

[0012] In some embodiments, the first fluid includes a reducing gas. In some embodiments, the reducing gas comprises hydrogen (H₂) and carbon monoxide (CO). In some embodiments, the second fluid includes a hydrocarbon fuel. In some embodiments, the third fluid includes an oxidant.

[0013] Some embodiments comprise directing the first fluid from the outlet of the body to a furnace. In some embodiments, the furnace comprises a direct-reduced iron (DRI) furnace. In some embodiments, at least a portion of the first fluid is produced by reforming natural gas in a reformer. [0014] The term "coupled" is defined as connected, although not necessarily directly, and not necessarily mechanically; two items that are "coupled" may be unitary with each other. The terms "a" and "an" are defined as one or more unless this disclosure explicitly requires otherwise. The term "substantially" is defined as largely but not necessarily wholly what is specified (and includes what is specified; e.g., substantially 90 degrees includes 90 degrees and substantially parallel includes parallel), as understood by a person of ordinary skill in the art. In any disclosed embodiment, the terms "substantially" and "approximately" may be substituted with "within [a percentage] of what is specified, where the percentage includes .1, 1, 5, and 10 percent.

[0015] The phrase "and/or" means and or. To illustrate, A, B, and/or C includes: A alone, B alone, C alone, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C. In other words, "and/or" operates as an inclusive or.

[0016] Further, a device or system that is configured in a certain way is configured in at least that way, but it can also be configured in other ways than those specifically described.

[0017] The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), and "include" (and any form of include, such as "includes" and "including") are open-ended linking verbs. As a result, an apparatus that "comprises," "has," or "includes" one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Likewise, a method that "comprises," "has," or "includes" one or more steps possesses those one or more steps, but is not limited to possessing only those one or more steps. [0018] Any embodiment of any of the apparatuses, systems, and methods can consist of or consist essentially of - rather than comprise/have/include - any of the described steps, elements, and/or features. Thus, in any of the claims, the term "consisting of or "consisting essentially of can be substituted for any of the open-ended linking verbs recited above, in order to change the scope of a given claim from what it would otherwise be using the open- ended linking verb.

[0019] The feature or features of one embodiment may be applied to other embodiments, even though not described or illustrated, unless expressly prohibited by this disclosure or the nature of the embodiments.

[0020] In the context of the present invention, twenty embodiments are now described. Embodiment 1 is a manifold. The manifold includes a body defining an inlet; an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being in fluid communication with and having a larger maximum transverse dimension than the inlet; and an outlet in fluid communication with the chamber; one or more first conduits in fluid communication with the chamber, each having an outlet configured to provide a first fluid to the chamber; and one or more second conduits in fluid communication with the chamber, each having an outlet configured to provide a second fluid to the chamber and being at least partially surrounded by a respective one of the one or more first conduits; wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits. Embodiment 2 is the manifold of embodiment 1, wherein the outlet of each of the one or more first conduits is defined by the sidewall of the body. Embodiment 3 is the manifold of embodiment 1 or 2, wherein, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit. Embodiment 4 is the manifold of any of embodiments 1 to 3, wherein at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle that is approximately 90°. Embodiment 5 is the manifold of any of embodiments 1 to 4, wherein a minimum distance between the center of one of the one or more second outlets that is closest to the interior surface and the interior surface is 95% or less of a minimum distance between the center of one of the one or more first outlets that is closest to the interior surface and the interior surface. Embodiment 6 is the manifold of any of embodiments 1 to 5, wherein the inlet of the body, the chamber, and the outlet of the body are coaxial. [0021] Embodiment 7 is a method, the method including the steps of directing a first fluid through an inlet and an outlet of a body of a manifold, the body including an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being disposed between and in fluid communication with the inlet and the outlet and having a larger maximum transverse dimension than the inlet; directing a second fluid into the chamber through an outlet of each of one or more first conduits; and directing a third fluid into the chamber through an outlet of each of one or more second conduits; wherein each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits; and wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits. Embodiment 8 is the method of embodiment 7, wherein, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit. Embodiment 9 is the method of embodiment 7 or 8, wherein the first fluid includes a reducing gas; the second fluid includes a hydrocarbon fuel; and the third fluid includes an oxidant.

[0022] Embodiment 10 is a method, the method including the steps of directing a first fluid including a reducing gas through an inlet and an outlet of a body of a manifold, the body including an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being disposed between and in fluid communication with the inlet and the outlet and having a larger maximum transverse dimension than the inlet; directing a second fluid including a hydrocarbon fuel into the chamber through an outlet of each of one or more first conduits; and directing a third fluid including an oxidant into the chamber through an outlet of each of one or more second conduits; wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits. Embodiment 11 is the method of embodiment 10, wherein at least one of the one or more second conduits is not surrounded by one of the one or more first conduits. Embodiment 12 is the method of embodiment 10, wherein each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits. Embodiment 13 is the method of embodiment 12, wherein, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit. Embodiment 14 is the method of any of embodiments 10 to 13, wherein the reducing gas contains hydrogen (H₂) and carbon monoxide (CO). Embodiment 15 is the method of any of embodiments 9 to 14, including the step of directing the first fluid from the outlet of the body to a furnace. Embodiment 16 is the method of embodiment 15, wherein the furnace includes a direct-reduced iron (DRI) furnace. Embodiment 17 is the method of any of embodiments 9 to 16, wherein at least a portion of the first fluid is produced by reforming natural gas in a reformer. Embodiment 18 is the method of any of embodiments 7 to 17, wherein a minimum distance between the center of one of the one or more second outlets that is closest to the interior surface and the interior surface is 95% or less of a minimum distance between the center of one of the one or more first outlets that is closest to the interior surface and the interior surface. Embodiment 19 is the method of any of embodiments 7-18, wherein at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle that is approximately 90°. Embodiment 20 is the method of any of embodiments 7 to 19, wherein the sidewall is cylindrical.

[0023] Some details associated with the embodiments are described above and others are described below.

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The following drawings illustrate by way of example and not limitation. For the sake of brevity and clarity, every feature of a given structure is not always labeled in every figure in which that structure appears. Identical reference numbers do not necessarily indicate an identical structure. Rather, the same reference number may be used to indicate a similar feature or a feature with similar functionality, as may non-identical reference numbers.

[0025] FIG. 1 is a schematic view of one embodiment of the present systems, including a reformer, a manifold, and a furnace. [0026] FIG. 2 is an end view of one embodiment of the present manifolds, which may be suitable for use in the system of FIG. 1. [0027] FIG. 3 is a side view of the manifold of FIG. 2.

[0028] FIG. 4 is a cross-sectional end view of the manifold of FIG. 2, taken along line 4-4 of FIG. 3, shown without the second conduits.

[0029] FIG. 5 is a cross-sectional perspective view of the manifold of FIG. 2, taken along line 5-5 of FIG. 2, and is drawn to scale.

[0030] FIGs. 6A-6D each depict an exemplary placement of a first conduit outlet relative to a second conduit outlet that may be suitable for use in some embodiments of the present manifolds.

[0031] FIG. 7 depicts the volume of a sample one of the present manifolds, divided into radial slices.

[0032] FIG. 8 depicts a radial slice of the volume of a comparative manifold.

[0033] FIGs. 9A and 9B show fluid temperature within the comparative and sample manifolds, respectively.

[0034] FIGs. 10A and 10B show mass fraction of "h"— an indication of carbon generated due to natural gas cracking— for fluid within the comparative and sample manifolds, respectively.

DETAILED DESCRIPTION

[0035] FIG. 1 is a schematic view of one embodiment 10 of the present systems within which an embodiment (e.g., 54) of the present manifolds can be used. In system 10, flows of material are indicated by dashed lines. Structures for conveying such flows of material can include conduits, tubes, pipes, hoppers, and/or the like. System 10 can be configured to produce DRI. For example, system 10 can include a furnace 14 within which a direct- reduced iron precursor 18 (e.g., iron oxide pellets, lump ores, and/or the like) can be heated and exposed to a reducing gas 22 to produce DRI. Such a reducing gas (e.g., 22) can comprise, for example, hydrogen, carbon monoxide, reformed gas, syngas, and/or the like, which can be produced from, for example, natural gas, coke oven gas, coal, and/or the like.

[0036] To illustrate, in system 10, reducing gas 22 can be produced using a reformer 26. Reformer 26 can comprise any suitable reformer, including, for example, a steam reformer, in which a reducing gas precursor 30 is heated in the presence of steam and a catalyst to produce reducing gas 22, an autothermal reformer, in which oxygen and carbon dioxide and/or steam are reacted with a reducing gas precursor 30 to produce a reducing gas 22, a partial oxidation reformer, in which a sub-stoichiometric mixture of a reducing gas precursor 30 and an oxidant are combusted to produce a reducing gas 22, or the like. In other embodiments, such a reducing gas (e.g., 22) can be produced in any suitable fashion, such as, for example, by gasifying coal in a gasifier. In some systems, a reducing gas (e.g., 22) can comprise a reducing gas precursor (e.g., 30) (e.g., in such systems, a reformer 26 can be omitted).

[0037] In some instances, it may be desirable to enrich reducing gas 22 prior to introducing the reducing gas to furnace 14 (e.g., to produce enriched reducing gas 34). For example, a hydrocarbon fuel 38 (e.g., natural gas, methane, ethane, butane, propane, naphtha, and/or the like, whether liquid and/or gas) can be added to reducing gas 22 to facilitate (e.g., further) reforming of the reducing gas, thereby enhancing the effectiveness of the reducing gas within furnace 14. For further example, an oxidant 42 (e.g., oxygen (O2), air, CO2, and/or the like, whether liquid and/or gas) can be added to reducing gas 22 to increase temperatures within furnace 14 (e.g., to offset temperature decreases within the furnace due to the addition of hydrocarbon fuel 38 to the reducing gas). When hydrocarbon fuel 38 and/or oxidant 42 are added to reducing gas 22, high temperatures, sub-optimal flow characteristics (e.g., recirculation regions and/or the like that can cause increased residence time for the hydrocarbon fuel at or proximate to the point of addition), and/or the like can lead to cracking and/or combustion of the hydrocarbon fuel and thus carbon deposition within equipment at or proximate to the point of addition. Such carbon deposition can decrease the effectiveness of such equipment and/or increase the maintenance requirements of such equipment.

[0038] As will be described in more detail below, an embodiment 54 of the present manifolds can be used to enrich reducing gas 22 with hydrocarbon fuel 38 and oxidant 42 and direct enriched reducing gas 34 to furnace 14 while mitigating carbon deposition within the manifold. System 10 is provided solely by way of illustration, as the present manifolds (e.g., 54) can be used in any suitable system in which it is desirable to mix fluids, at least one of which is combustible, while mitigating deposition of combustion byproducts.

[0039] Referring now to FIGs. 2-5, shown is manifold 54. Manifold 54 can include a body 58 defining an inlet 62 and an outlet 66. Inlet 62 can be in fluid communication with outlet 66 such that a first fluid, such as reducing gas 22, can enter body 58 via the inlet and exit the body via the outlet. Body 58 can be coupled to other structures (e.g., conduit(s), furnace 14, and/or the like) to permit fluid communication between inlet 62, outlet 66, and the other structures in any suitable fashion, such as, for example, via flange(s), fastener(s), and/or the like. Inlet 62 can be co-axial with outlet 66; for example, a longitudinal axis of the inlet can be substantially aligned with a longitudinal axis of the outlet. Inlet 62 and outlet 66 can each have any suitable size or shape. For example, inlet 62 and/or outlet 66 can have an inner cross-sectional perimeter that is circular, elliptical, otherwise rounded, triangular, square, rectangular, or otherwise polygonal.

[0040] Body 58 of manifold 54 can define a chamber 82 that is disposed between and in fluid communication with inlet 62 and outlet 66. More particularly, chamber 82 can be defined, at least in part, by an interior sidewall 78 of body 58. Chamber 82 can have a maximum transverse dimension 86 that is larger than a maximum transverse dimension 90 of inlet 62. For example, maximum transverse dimension 90 of inlet 62 can be less than or approximately equal to any one of, or between any two of: 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, or 90% (e.g., approximately 40%) of maximum transverse dimension 86 of chamber 82. Sidewall 78, and thus at least a portion of chamber 82, can have any suitable shape; for example, the sidewall can have an inner cross-sectional perimeter that is circular, elliptical, otherwise rounded, triangular, square, rectangular, or otherwise polygonal (e.g., the sidewall can be cylindrical, conical, or prismatic).

[0041] Body 58 of manifold 54 can include an interior surface 102 (e.g., a back wall) that extends between inlet 62 and sidewall 78. At least a portion of interior surface 102 can be angularly disposed relative to sidewall 78 at an angle 106. Angle 106 can be greater than or approximately equal to any one of, or between any two of: 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 100, 105, 110, 115, 120, or more degrees (e.g., approximately 90°). In the embodiment shown, interior surface 102 and sidewall 78 are smooth; however, in other embodiments, a manifold can include an interior surface (e.g., 102) and/or a sidewall (e.g., 78) having textured portion(s), protrusion(s) (e.g., ridge(s), bump(s), and/or the like), recess(es) (e.g., dimples), and/or the like, which can mitigate the formation of a boundary layer on the interior surface and/or the sidewall when fluid is flowing within the manifold. In this embodiment, interior surface 102 is planar; however, in other embodiments, a manifold can include an interior surface (e.g., 102) that is concave or convex (e.g., when viewed from an outlet 66 of the manifold).

[0042] Manifold 54 can include one or more first conduits 118, each in fluid communication with chamber 82 and having an outlet 122 configured to provide a second fluid, such as hydrocarbon fuel 38, to the chamber. For example, each of first conduit(s) 118 can extend through sidewall 78, for each of the first conduit(s), outlet 122 can be defined by the sidewall, and/or the like. More particularly, first conduit(s) 118 can be disposed along sidewall 78 such that the first conduit(s) are disposed around at least a portion of a periphery of chamber 82. Manifold 54 can include a (e.g., annular) fluid distribution chamber 126 disposed around or defined within at least a portion of sidewall 78 and in fluid communication with each of first conduit(s) 118 such that the second fluid can be provided from the fluid distribution chamber to the first conduit(s). Outlet(s) 122 of first conduit(s) 118 can have any suitable shape; for example, each outlet 122 can have an inner cross- sectional perimeter that is circular, elliptical, otherwise rounded, triangular, square, rectangular, or otherwise polygonal. A manifold (e.g., 54) can include any suitable number of first conduit(s) (e.g., 118), such as, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more first conduit(s).

[0043] Manifold 54 can include one or more second conduits 138, each in fluid communication with chamber 82 and having an outlet 142 configured to provide a third fluid, such as oxidant 42, to the chamber. For example, each of second conduit(s) 138 can extend through sidewall 78, for each of the second conduit(s), outlet 142 can be defined by the sidewall, and/or the like. More particularly, second conduit(s) 138 can be disposed along sidewall 78 such that the second conduit(s) are disposed around at least a portion of a periphery of chamber 82. The third fluid can be provided to second conduit(s) 138 in any suitable fashion; for example, manifold 54 can include a fluid distribution chamber in fluid communication with each of the second conduit(s) (e.g., similarly to as described above for fluid distribution chamber 126). Outlet(s) 142 of second conduit(s) 138 can have any suitable shape; for example, each outlet 142 can have an inner cross-sectional perimeter that is circular, elliptical, otherwise rounded, triangular, square, rectangular, or otherwise polygonal. A manifold (e.g., 54) can include any suitable number of second conduit(s) (e.g., 138), such as, for example, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or more second conduit(s).

[0044] Referring additionally to FIG. 6A, a center 150 of outlet 142 of at least one of (e.g., each of) second conduit(s) 138 can be closer to interior surface 102 of body 58 than is a center 146 of outlet 122 of at least one of (e.g., each of) first conduit(s) 118. For example, for at least one of (e.g., each of) outlet(s) 142, a minimum distance 148 between its center 150 and interior surface 102 can be less than or substantially equal to any one of, or between any two of: 95, 90, 85, 80, and 75% of a minimum distance 152, for at least one of (e.g., each of) outlet(s) 122, between its center 146 and the interior surface. In some embodiments, center 146 of each outlet 122 is farther from interior surface 102 than is center 150 of any outlet 142. A center (e.g., 146, 150) of an outlet (e.g., 122, 142) can be: (1) the centroid of a shape defined by an inner cross-sectional perimeter of the outlet; (2) the intersection of a longitudinal axis of the portion of the respective conduit (e.g., 118, 138) that defines the outlet with the exit plane of the outlet; (3) if the outlet is circular, the center of the circle; and/or the like. Such relative positioning of outlet(s) 122 and outlet(s) 142 can, for example: (1) encourage the third fluid from outlet(s) 142 to disturb fluid within manifold 54 at or proximate to interior surface 102 (e.g., decreasing the residence time of such fluid within the manifold); (2) if the first fluid and/or second fluid are combustible and the third fluid is an oxidant, encourage the third fluid from outlet(s) 142 to heat deposits on the interior surface (e.g., burning off the deposits); and/or the like.

[0045] In some embodiments, second conduit(s) (e.g., 138) of a manifold (e.g., 54) can be angled toward an interior surface (e.g., 102) of the manifold. For example, for at least one of the second conduit(s), a longitudinal axis of a portion of the conduit that defines its respective outlet (e.g., 142) can extend from the outlet and toward an inlet (e.g., 62) of the manifold. Such angled second conduit(s) (e.g., 138) can, for example, achieve the same or similar benefits described above for relative positioning of outlet(s) 122 and outlet(s) 142.

[0046] Referring additionally to FIG. 6A, at least one of (e.g., each of) second conduit(s) 138 can be at least partially surrounded by a respective one of first conduit(s) 118. For example, in this embodiment, for at least one of (e.g., each of) second conduit(s) 138: (1) none of a portion of the second conduit that defines its outlet 142 extends laterally beyond outlet 122 of one of first conduit(s) 118 that at least partially surrounds the second conduit (e.g., in any direction that is perpendicular to a longitudinal axis of a portion of the first conduit that defines its outlet); (2) an inner cross-sectional perimeter 166 of outlet 142 of the second conduit is completely surrounded by an inner cross-sectional perimeter 162 of outlet 122 of one of first conduit(s) 118 that at least partially surrounds the second conduit; and/or the like. For further example and as shown in FIGs. 6B and 6C, in some embodiments, for at least one of (e.g., each of) second conduit(s) (e.g., 138), an inner cross-sectional perimeter (e.g., 166) of an outlet (e.g., 142) of the second conduit is partially surrounded (e.g., 50% or more, FIG. 6B, less than 50%, FIG. 6C) by an inner cross-sectional perimeter (e.g., 162) of an outlet (e.g., 122) of one of first conduit(s) (e.g., 118) that at least partially surrounds the second conduit. Such partial surrounding of a second conduit (e.g., 138) by a first conduit (e.g., 118) can facilitate mixing of fluids flowing from the first and second conduits. As shown in FIG. 6D, in some embodiments, at least one of (e.g., each of) second conduit(s) (e.g., 138) is not surrounded (e.g., in whole or in part) by one of first conduit(s) (e.g., 118).

[0047] Some embodiments of the present methods comprise: directing a first fluid through an inlet (e.g., 62) and an outlet (e.g., 66) of a body (e.g., 58) of a manifold (e.g., 54), the body including an interior surface (e.g., 102) extending between the inlet and a sidewall (e.g., 78) that defines at least a portion of a chamber (e.g., 82), the chamber being disposed between and in fluid communication with the inlet and the outlet and having a larger maximum transverse dimension (e.g., 86) than that of the inlet (e.g., 90), directing a second fluid into the chamber through an outlet (e.g., 122) of each of one or more first conduits (e.g., 118), and directing a third fluid into the chamber through an outlet (e.g., 142) of each of one or more second conduits (e.g., 138), wherein a center (e.g., 150) of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center (e.g., 146) of the outlet of each of the one or more first conduits.

[0048] In some methods, the outlet of each of the one or more first conduits is defined by the sidewall of the body. In some methods, at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle (e.g., 106) that is approximately 90°. In some methods, the sidewall is cylindrical.

[0049] In some methods, at least one of the one or more second conduits is not surrounded by one of the one or more first conduits. In some methods, each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits. In some methods, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit.

[0050] In some methods, the first fluid includes a reducing gas (e.g., 22), the second fluid includes a hydrocarbon fuel (e.g., 38), and the third fluid includes an oxidant (e.g., 42). In some methods, the reducing gas comprises hydrogen (H₂) and carbon monoxide (CO).

[0051] Some methods comprise directing the first fluid from the outlet of the body to a furnace (e.g., 14). In some methods, the furnace comprises a DRI furnace. In some methods, at least a portion of the first fluid by reforming natural gas (e.g., as reducing gas precursor 30) in a reformer (e.g., 26).

EXAMPLES [0052] The present invention will be described in greater detail by way of specific examples. The following examples are offered for illustrative purposes only and are not intended to limit the invention in any manner. Those of skill in the art will readily recognize a variety of noncritical parameters that can be changed or modified to yield essentially the same results.

Comparison of Fluid Flow within One of the Present Manifolds and Fluid Flow within a

Comparative Manifold

[0053] Computational fluid dynamics simulations were used to compare fluid flow within a sample one of the present manifolds 54 and fluid flow within a comparative manifold. Though the sample and comparative manifolds were otherwise similar, in the sample manifold, the center of the outlet of each of the second conduits was closer to the interior surface than was the center of the outlet of each of the first conduits, and, in the comparative manifold, the outlet of each of the second conduits was concentric with (had a center that was coincident with the center of) the outlet of a respective one of the first conduits. [0054] To begin, each of the sample and comparative manifolds was modelled by its volume; FIG. 7 depicts the volume of the sample manifold divided into radial slices, and FIG. 8 depicts a radial slice of the volume of the comparative manifold. In FIGs. 7 and 8, some portions of the depicted volumes are labeled with reference numerals of the structures that define them. In the simulations, for each manifold, natural gas and oxygen were injected into the portion of the volume representative of the chamber as reducing gas was flowed through that portion, where the injection of natural gas and oxygen were through portions of the volume representative of the first and second conduits, respectively. For each manifold, the results of the simulations were visualized for a slice of the volume (FIGs. 7 and 8) as shown in FIGs. 9A-10B. [0055] FIGs. 9A and 9B show fluid temperature within the comparative and sample manifolds, respectively. For each of the manifolds, combustion of natural gas resulted in increased temperature proximate the interior surface. Via positioning of its second conduits closer to the interior surface; however, the sample manifold achieved improved combustion proximate the interior surface when compared to the comparative manifold, resulting in a more concentrated high temperature region proximate the interior surface within the sample manifold than within the comparative manifold. Moreover, in the sample manifold, temperature of fluid downstream of the first and second conduits was generally higher than in the comparative manifold. [0056] FIGs. 10A and 10B show the mass fraction of "h"— an indication of carbon generated due to natural gas cracking— for fluid within the comparative and sample manifolds, respectively. As shown, improved combustion proximate the interior surface in the sample manifold resulted in a lower mass fraction of "h" proximate the interior surface when compared to the comparative manifold. Indeed, in the sample manifold, the largest concentrations of "h" were located downstream of the first and second conduits, relatively far from the interior surface.

[0057] The above specification and examples provide a complete description of the structure and use of illustrative embodiments. Although certain embodiments have been described above with a certain degree of particularity, or with reference to one or more individual embodiments, those skilled in the art could make numerous alterations to the disclosed embodiments without departing from the scope of this invention. As such, the various illustrative embodiments of the methods and systems are not intended to be limited to the particular forms disclosed. Rather, they include all modifications and alternatives falling within the scope of the claims, and embodiments other than the one shown may include some or all of the features of the depicted embodiment. For example, elements may be omitted or combined as a unitary structure, and/or connections may be substituted. Further, where appropriate, aspects of any of the examples described above may be combined with aspects of any of the other examples described to form further examples having comparable or different properties and/or functions, and addressing the same or different problems. Similarly, it will be understood that the benefits and advantages described above may relate to one embodiment or may relate to several embodiments.

[0058] The claims are not intended to include, and should not be interpreted to include, means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) "means for" or "step for," respectively.

Claims

1. A manifold comprising:

a body defining:

an inlet;

an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being in fluid communication with and having a larger maximum transverse dimension than the inlet; and

an outlet in fluid communication with the chamber;

one or more first conduits in fluid communication with the chamber, each having an outlet configured to provide a first fluid to the chamber; and

one or more second conduits in fluid communication with the chamber, each having an outlet configured to provide a second fluid to the chamber and being at least partially surrounded by a respective one of the one or more first conduits; wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits.

2. The manifold of claim 1, wherein the outlet of each of the one or more first conduits is defined by the sidewall of the body.

3. The manifold of claim 1 or 2, wherein, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit.

4. The manifold of claim 1 or 2, wherein at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle that is approximately 90°.

5. The manifold of claim 1 or 2, wherein a minimum distance between the center of one of the one or more second outlets that is closest to the interior surface and the interior surface is 95% or less of a minimum distance between the center of one of the one or more first outlets that is closest to the interior surface and the interior surface.

6. The manifold of claim 1 or 2, wherein the inlet of the body, the chamber, and the outlet of the body are coaxial.

7. A method comprising:

directing a first fluid through an inlet and an outlet of a body of a manifold, the body including an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being disposed between and in fluid communication with the inlet and the outlet and having a larger maximum transverse dimension than the inlet;

directing a second fluid into the chamber through an outlet of each of one or more first conduits; and

directing a third fluid into the chamber through an outlet of each of one or more second conduits;

wherein each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits; and

wherein a center of the outlet of each of the one or more second conduits is closer to the interior surface of the body than is a center of the outlet of each of the one or more first conduits.

8. The method of claim 7, wherein, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit.

9. The method of claim 7 or 8, wherein:

the first fluid includes a reducing gas;

the second fluid includes a hydrocarbon fuel; and

the third fluid includes an oxidant.

10. A method comprising: directing a first fluid including a reducing gas through an inlet and an outlet of a body of a manifold, the body including an interior surface extending between the inlet and a sidewall that defines at least a portion of a chamber, the chamber being disposed between and in fluid communication with the inlet and the outlet and having a larger maximum transverse dimension than the inlet;

directing a second fluid including a hydrocarbon fuel into the chamber through an outlet of each of one or more first conduits; and directing a third fluid including an oxidant into the chamber through an outlet of each of one or more second conduits;

11. The method of claim 10, wherein at least one of the one or more second conduits is not surrounded by one of the one or more first conduits.

12. The method of claim 10, wherein each of the one or more second conduits is at least partially surrounded by a respective one of the one or more first conduits.

13. The method of claim 12, wherein, for at least one of the one or more second conduits, none of a portion of the second conduit that defines its outlet extends laterally beyond the outlet of the respective first conduit.

14. The method of any of claims 10 to 13, wherein the reducing gas comprises hydrogen (H₂) and carbon monoxide (CO).

15. The method of any of claims 10-13, comprising directing the first fluid from the outlet of the body to a furnace.

16. The method of claim 15, wherein the furnace comprises a direct-reduced iron (DRI) furnace.

17. The method of any of claims 10-16, wherein at least a portion of the first fluid is produced by reforming natural gas in a reformer.

18. The method of any of claims 7 or 10, wherein a minimum distance between the center of one of the one or more second outlets that is closest to the interior surface and the interior surface is 95% or less of a minimum distance between the center of one of the one or more first outlets that is closest to the interior surface and the interior surface.

19. The method of any of claims 7 or 10, wherein at least a portion of the interior surface of the body is angularly disposed relative to the sidewall of the body at an angle that is approximately 90°.

20. The method of any of claims 7 or 10, wherein the sidewall is cylindrical.