System and method for hydrogen use in a blast furnace
A system for uniform hydrogen and carrier gas distribution in blast furnaces addresses non-uniformity issues, enabling stable and efficient hydrogen injection, reducing carbon emissions and improving operational stability.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- CLEVELAND CLIFFS STEEL PROPERTIES INC
- Filing Date
- 2025-01-22
- Publication Date
- 2026-07-30
AI Technical Summary
The use of hydrogen in blast furnaces leads to non-uniform Raceway Flame Temperature and heat distribution, causing instability and limiting hydrogen injection, while existing methods often use batch amounts suitable for only a few production cycles.
A system for uniform distribution of hydrogen and combustible carrier gas mixture across tuyeres using a mixing conduit, double-block and bleed valves, and controlled gas delivery to ensure stable operation.
Achieves stable and efficient hydrogen injection, reducing carbon emissions, and improving operational stability and efficiency in blast furnaces.
Smart Images
Figure US2025012495_30072026_PF_FP_ABST
Abstract
Description
SYSTEM AND METHOD FOR HYDROGEN USE IN ABLAST FURNACEBACKGROUND
[0001] A blast furnace is a key component in the steelmaking process, used for smelting iron ore to produce molten iron, or "pig iron," which is then used as a primary material in steel production. The process involves layering iron ore, coke (a carbon-rich substance derived from coal), and fluxes inside the furnace. Air is blasted into the furnace at high speeds and temperatures through nozzles called tuyeres, causing the coke to bum and produce carbon monoxide, which reduces the iron ore to iron. The molten iron collects at the bottom of the furnace, while impurities form slag, which floats on top of the iron and can be removed. This method is widely used due to its efficiency in producing large quantities of molten iron.DESCRIPTION OF DRAWINGS
[0002] While the specification concludes with claims which particularly point out and distinctly claim the embodiments provided herein, it is believed the present disclosure will be better understood from the following description of certain examples taken in conjunction with the accompanying examples and figures.
[0003] FIG. 1 shows a schematic front view of an apparatus used for smelting iron ore that includes a blast furnace.
[0004] FIG. 2 shows a block diagram of a method of using a gas mixture including hydrogen gas with the apparatus of FIG. 1.
[0005] The figures are not intended to be limiting in any way, and it is contemplated that various embodiments of the present disclosure may be carried out in a variety of other ways. The accompanying figures incorporated in and forming a part of the specification show aspects of the claimed embodiments, and together with the description serve to explain various principles; it being understood, however, that the embodiments provided herein are not limited to what is shown in the figures.DETAILED DESCRIPTION
[0006] The following description of certain examples should not be used to limit the scope of the present disclosure. Other examples, features, aspects, embodiments, and advantages will become apparent to those skilled in the art from the following description. As will be realized, the embodiments provided herein are capable of other aspects.Accordingly, the examples, figures, and descriptions should be regarded as illustrative in nature and not restrictive.
[0007] In the steel making process described above using a blast furnace requires significant energy and produces significant carbon emissions with the combustion processes. There is a desire across the industry to decarbonize, meaning to reduce the carbon footprint including greenhouse gas emissions. The present disclosure relates to apparatuses, systems, and methods for improving the environmental impact of blast furnaces by incorporating hydrogen gas as a combustion fuel and reductant for the blast furnace. The result is a reduced carbon footprint including a reduction in greenhouse gas emissions, such as carbon dioxide. However, the use of hydrogen in a blast furnace can lead to decrease in temperature of the flame in front of the tuyeres (known as Raceway Flame Temperature) and also change the heat distribution in front of the tuyeres. Applicants have discovered that a non-uniform hydrogen distribution among the tuyeres can lead to a non-uniform Raceway Flame Temperature and non-uniform heat distribution in front of the various tuyeres. Such lack of uniformity can lead to instability within the furnace. Ultimately, a non-uniform distribution will limit the total quantity of hydrogen (e.g., H2) that can be injected. For this reason, uniformity of H2 distribution among the tuyeres provided by the embodiments described herein can provide more stable operation and ultimately a higher total H2 injection. Many previous efforts to incorporate hydrogen utilized a batch amount of hydrogen, i.e., a limited quantity suitable for only a few production cycles or only a subset of tuyeres. As will be described in greater detail below and with reference to the figures, in the present embodiments, hydrogen gas is used in combination with another combustible carrier gas to achieve more uniform gas mixture delivery and distribution across a plurality of blast furnace tuyeres. The incorporation of hydrogen in this manner improves the reduction process, leading tohigher efficiency and reduced carbon emissions. For example, improvements to the uniformity of distribution of the hydrogen gas and combustible carrier gas components within the mixture can improve the stability of operation of the blast furnace. Benefits to operational stability, according to the embodiments provided herein, can include less variability of fuel and other inputs, increased efficiency, and smoother operation.Furthermore, the embodiments provided herein can be utilized for substantially continuous hydrogen injection in blast furnaces. Accordingly, hydrogen can be injected using all of the tuyeres of the blast furnace during normal operation, substantially continuously over a period time spanning multiple throughputs of iron ore. At least some of the present embodiments include a double-block and bleed valve system to safely provide controlled and stable hydrogen containing gas delivery to the furnace.
[0008] FIG. 1 schematically shows an apparatus (10) for smelting iron ore. The apparatus (10) includes a blast furnace (12) having a furnace body (14) configured to receive the materials for smelting iron ore, including iron ore itself, coke, and flux materials such as limestone. The apparatus (10) includes a plurality of tuyeres (16) that are each configured to supply inputs into the furnace body (14). Each tuyere (16) serves as the entry point for hot blast air and fuel that are combusted to generate heat and reducing gases. Hot blast air is supplied from one or more hot stoves to a bustle pipe (17) and distributed through the plurality of tuyeres (16). The fuel can include a tuyere input gas (18) that is delivered to each tuyere (16) through a lance pipe (one per tuyere) and configured to inject the tuyere input gas (18) into the hot blast air. Optionally, each tuyere (16) can include one or more additional lances for supplying additional fuel, such as, for example, pulverized coal. Alternatively or additionally, another fuel can be injected into the hot blast air via the same lance as the tuyere input gas (18). In some versions, one or more tuyeres of the plurality of tuyeres (16) may be positioned at different heights along a longitudinal axis of the blast furnace (12).
[0009] The apparatus (10) includes a supply ring (20) fluidly connected with the plurality of tuyeres (16) and is configured to distribute the tuyere input gas (18) into the blast furnace (12) via the tuyeres (16). In the present example, the tuyere input gas (18) is delivered to the plurality of tuyeres (16) at a substantially equal rate to thereby delivertuyere input gas (18) to the blast furnace (12) substantially uniformly. As used herein, the phrase, fluidly connect can mean that a flow path is provided between a first object and a second object such that a fluid can be transmitted from the first object to the second object via the flow path.
[0010] Upstream from the supply ring (20) is a mixing conduit (22) having an injection point (24) and a distribution end (25). Fluidly connected with the mixing conduit (22) is a carrier gas conduit (26) configured to deliver a carrier gas (28) to the mixing conduit (22). Similarly, fluidly connected with the mixing conduit (22) is a hydrogen gas conduit (30) configured to deliver a hydrogen gas (32) to the mixing conduit (22). The injection point (24) is the portion of the mixing conduit (22) where the carrier gas (28) and the hydrogen gas (32) first become coexistent. In the illustrated version, the carrier gas conduit (26) fluidly connects with the mixing conduit (22) in a manner where the mixing conduit (22) is an extension of the carrier gas conduit (26). Also in the illustrated version, the hydrogen gas conduit (30) connects with the mixing conduit (22) at the injection point (24) of the mixing conduit (22). In some other versions, both the hydrogen gas conduit (30) and the carrier gas conduit (26) can be fluidly connected with the mixing conduit (22) at the injection point (24) of the mixing conduit (22). In still other versions, the carrier gas conduit (26) can be fluidly connected with the injection point (24) of the mixing conduit (22) while the hydrogen gas conduit (30) is either fluidly connected with a separate injection point (not shown) of the mixing conduit (22) or the mixing conduit (22) can be an extension of the hydrogen gas conduit (30). In whichever configuration is used, the mixing conduit (22) is configured to receive both the combustible carrier gas (28) and the hydrogen gas (32) such that they form a gas mixture — the tuyere input gas (18).
[0011] The apparatus (10) further includes a hydrogen gas source or supply (34) with piping to deliver the hydrogen gas (32) to the hydrogen gas conduit (30). Similarly, there is a combustible carrier gas source or supply (36) with piping to deliver the combustible carrier gas (28) to the carrier gas conduit (26). The hydrogen gas supply (34) and / or the combustible carrier gas supply (36) do not need to be batch systems like supply tanks. In certain preferred embodiments, the hydrogen gas supply (34) and / or the combustiblecarrier gas supply (36) may be continuous systems like connections with a commercial supply line.
[0012] The apparatus (10) further optionally includes one or more double-block and bleed valves (38), flow measurement, and a control valve, to regulate and control the volume flow rate, which are incorporated into the gas piping. Each double-block and bleed valve (38) comprise two block valves arranged in series, with a bleed valve located between them. Double-block and bleed valves (38) are configured to isolate a flow by closing the block valves and then venting the space between the block valves using the bleed valve. In one version of apparatus (10), a double-block and bleed valve (38) is installed inline between the hydrogen gas conduit (30) and the mixing conduit (22), and / or installed inline between the carrier gas conduit (26) and the mixing conduit (22). In one example, having the double-block and bleed valve (38) associated with the hydrogen gas flow provides for a stable and controlled way to isolate the hydrogen gas flow from the combustible carrier gas flow. Still further it may provide for a stable and controlled way to isolate either or both gases from reaching the supply ring (20) and / or the plurality of tuyeres (16). In view of the teachings herein, other locations for double-block and bleed valves will be apparent to those of ordinary skill in the art.
[0013] Referring collectively FIGS. 1 and 2, a block diagram of method steps is shown to illustrate a method (100) that incorporates hydrogen gas (32) with an apparatus (10) for smelting iron ore that includes a blast furnace (12). In a step (102) of the method (100), the hydrogen gas (32) is supplied via the hydrogen gas conduit (30) to the mixing conduit (22). In a step (104) of the method (100), the combustible carrier gas (28) is supplied via the carrier gas conduit (26) to the mixing conduit (22). In a step (106) of the method (100), the hydrogen gas (32) is mixed with the combustible carrier gas (28) within the mixing conduit (22). This mixture of the hydrogen gas (32) and the combustible carrier gas (28) forms the tuyere input gas (18). In a step (108) of the method (100), the tuyere input gas (18) is supplied to a supply ring (20) that is fluidly connected with the mixing conduit (22). Accordingly, the hydrogen gas (32) and the combustible carrier gas (28) can be mixed together prior to being supplied to the supply ring (20). The gases generally flow in the direction of the arrows provided in FIG. 1.Furthermore, in a step (110) of the method (100), the tuyere input gas (18) is supplied to the plurality of tuyeres (16) via the supply ring (20). With method (100), mixing of the hydrogen gas (32) and the combustible carrier gas (28) between the injection point (24) and the distribution end (25) can improve the uniformity of gas distribution, and lead to more stable temperature operation of the blast furnace (12).
[0014] In some versions of the method (100), one or both of the hydrogen gas conduit (30) and the carrier gas conduit (26) are fluidly connected to the mixing conduit (22) at the injection point (24) of the mixing conduit (22). In some versions of the method (100), the mixing of the hydrogen gas (32) and the combustible carrier gas (28) occurs downstream of the injection point (24) within the mixing conduit (22). In some versions of the method (100), the supply ring (20) can be fluidly connected with the mixing conduit (22) at the distribution end (25) of the mixing conduit (22) and offset an injection length relative to the injection point (24) of the mixing conduit (22).Accordingly, the injection length can be defined as the overall length of the mixing conduit (22) between the injection point (24) and the distribution end (25) including any section that has been bent, where any bend (40) is considered part of the overall length.
[0015] The mixing conduit (22) can be a pipe or tube of sufficient dimensions to promote sufficiently uniform distribution of the hydrogen gas (32) and the combustible carrier gas (28) within the tuyere input gas (18). In some embodiments, the injection length, the average interior diameter, or both can be controlled to deliver tuyere input gas (18) that is substantially uniformly mixed to the supply ring (20). The average interior diameter corresponds to the flow path provided by the mixing conduit (22), i.e., the flow path bounded by the interior walls of the mixing conduit (22). An offset ratio is given by the injection length of the mixing conduit (22) divided by the average interior diameter the mixing conduit (22) averaged over the injection length, using the same distance units. According to the embodiments provided herein, the offset ratio can be greater than or equal to about 20, such as, for example, greater than or equal to about 25 in one embodiment, greater than or equal to about 50 another embodiment, or greater than or equal to about 70 in a further embodiment. In some versions, there may be additionalmodifications at the injection point (24), such as a sparger to provide improved mixing for relatively small injection lengths.
[0016] In some embodiments, distribution of the hydrogen gas (32) and the combustible carrier gas (28) can be enhanced further by including bends (40) within the mixing conduit (22). In some embodiments, the mixing conduit (22) can include at least two bends (40). Alternatively or additionally, the angle (42) of bends (40) can be controlled to promote mixing. According to the embodiments provided herein, a sum of the angles (42) of the bends (40) formed in the mixing conduit (22) can be greater than or equal to about 180° such as, for example, greater than or equal to about 225°.
[0017] In some examples, the combustible carrier gas (28) may comprise the majority of the total gas mixture. In one embodiment, the combustible carrier gas (28) may comprise at least 80% of the total gas mixture — the tuyere input gas (18) — with the hydrogen gas (32) comprising the remainder. In the above example, hydrogen gas (32) is described as a percentage of the tuyere input gas (28) at about 20% or less. In other versions this ratio of gases may differ. However, depending on the amount of the carrier combustible gas (28), hydrogen gas (32) rate may be greater than or equal to 1 pound per net ton of hot metal (Ib / nthm) produced by the blast furnace (12) such as, for example, greater than or equal to about 1 Ib / nthm and less than or equal to about 10 Ib / nthm. By way of example only, and not limitation, in another example the hydrogen gas (32) may comprise up to about 50% of the total gas mixture with the combustible carrier gas (28) making up the remainder. Still in some versions the volume fraction of the hydrogen gas (32) in the tuyere input gas (18) may exceed the volume fraction of the combustible carrier gas (28). For instance, the hydrogen gas (32) may comprise 80% to 95% of the tuyere input gas (18) by volume with the combustible carrier gas (28) comprising the remainder. In view of the teachings herein, other ratios of gases will be apparent to those of ordinary skill in the art.
[0018] With respect to the combustible carrier gas (28), in some versions the combustible carrier gas (28) is natural gas (mainly CH4), although in view of the teachings herein other combustible carrier gases or mixtures defining the carrier gas will be apparent to those of ordinary skill in the art. In some versions, other inputs through separate conduitsystems to the plurality of tuyeres (16) include one or more of the following: oxygen (O2) with nitrogen (N2), pure oxygen (O2), and / or fuel such as coal injection.
[0019] In some examples, the hydrogen gas (32), the combustible carrier gas (28), or both can be heated prior to mixing. For instance, a heater (41) can be used in line with the hydrogen gas supply to raise the temperature of the incoming hydrogen gas (32). Using heated or hot hydrogen or carrier gas can benefit the method because the tuyere input gas (18) enters the blast furnace (12) at a higher controlled temperature to allow a higher hydrogen rate or higher combustible carrier gas rate for stable and controlled combustion and reduction reactions within the blast furnace (12).
[0020] In some examples, the apparatus (10) may also include additional features such as one or more sensors (42) and a control unit (44) to monitor conditions of the blast furnace (12) based on inputs from the one or more sensors (42). For instance the one or more sensors (42) may measure attributes including temperature, pressure, gas composition, flow rates, among others. The one or more sensors (42) may send real-time data to the control unit (44), which can adjust the ratio of hydrogen gas to combustible carrier gas, as well as the flow rates of either or both of the gases, to control furnace performance. In one example, the one or more sensors (42) may include an emergency shut-off feature that activates in response to a detected gas leak or pressure anomality. In view of the teachings herein, other ways to configure the one or more sensors (42) and control unit (44) to control the blast furnace (12) will be apparent to those of ordinary skill in the art.
[0021] In one example, the method (100) used about 18,000 linear feet of supply pipe to deliver flow rates of hydrogen gas of 30,000 to 100,000 standard cubic feet per hour (SCFH) (0.23 m3 / s to 0.79 m3 / s) from a supply with a source pressure of about 200 pounds per square inch (psi). At 100,000 SCFH, the target volume of hydrogen in the tuyere input gas is about 7%. Still in other examples the flow of hydrogen gas can be up to 800,000 SCFH (6.3 m3 / s), which results in the target volume of hydrogen in the tuyere input gas as about 20%, depending on the volume flow rate of the carrier gas. The supply pipe in the above example was a 6 inch schedule 80 pipe.
[0022] According to a first exemplary embodiment, a method for operating a blast furnace, which can include a plurality of tuyeres, a hydrogen gas can be supplied via a hydrogen conduit to a mixing conduit. A combustible carrier gas can be supplied via a carrier gas conduit to the mixing conduit, wherein the carrier gas conduit, the hydrogen conduit, or both are fluidly connected to the mixing conduit at an injection point. The hydrogen gas and the combustible carrier gas can be mixed within the mixing conduit downstream of the injection point, whereby a tuyere input gas can be formed. The tuyere input gas can be supplied to a supply ring fluidly connected to the mixing conduit offset an injection length relative to the injection point of the mixing conduit. The mixing conduit can have an average interior diameter averaged over the injection length. The tuyere input gas can be supplied to the plurality of tuyeres via the supply ring.
[0023] According to a second exemplary embodiment, an offset ratio can be equal to the injection length divided by the average interior diameter of the mixing conduit, and wherein the offset ratio can be greater than 20. According to a third exemplary embodiment, wherein the offset ratio can be greater than 25. According to a fourth exemplary embodiment, wherein the offset ratio can be greater than 50. According to a fifth exemplary embodiment, wherein the offset ratio can be greater than 70.
[0024] In a sixth exemplary embodiment, any of the first through fifth exemplary embodiments of a method can further include heating the hydrogen gas prior to mixing the hydrogen gas and the combustible carrier gas within the mixing conduit.
[0025] In a seventh exemplary embodiment, for any of the first through sixth exemplary embodiments, the combustible carrier gas can be natural gas.
[0026] In an eighth exemplary embodiment, for any of the first through seventh exemplary embodiments, the tuyere input gas can include up to 20% hydrogen gas by volume. In a ninth exemplary embodiment, for any of the first through seventh exemplary embodiments, the tuyere input gas can include up to 50% hydrogen gas by volume. In a tenth exemplary embodiment, for any of the first through seventh exemplary embodiments, the tuyere input gas can include up to 80% hydrogen gas by volume. In aneleventh exemplary embodiment, for any of the first through seventh exemplary embodiments, the tuyere input gas can include up to 95% hydrogen gas by volume.
[0027] In a twelfth exemplary embodiment, any of the first through eleventh exemplary embodiments of a method can further include delivering the tuyere input gas at an equal rate across each tuyere of the plurality of tuyeres.
[0028] In a thirteenth exemplary embodiment, any of the first through twelfth exemplary embodiments of a method can further include using a double-block and bleed valve to selectively isolate the hydrogen gas from the combustible carrier gas.
[0029] In a fourteenth exemplary embodiment, for any of the first through thirteenth exemplary embodiments, a flow rate of hydrogen gas supplied to the mixing conduit can be based at least in part on a temperature at one or more tuyeres of the plurality of tuyeres.
[0030] In a fifteenth exemplary embodiment, for any of the first through fourteenth exemplary embodiments, the mixing conduit can have at least two bends. Alternatively or additionally, a cumulative total of angles of the bends of the mixing conduit can be greater than or equal to 180°.
[0031] As shown and described herein, an exemplary method for operating a blast furnace having a plurality of tuyeres includes supplying a hydrogen gas via a hydrogen conduit to a mixing conduit. Additionally, the method includes supplying a combustible carrier gas via a carrier gas conduit to the mixing conduit, wherein the carrier gas conduit, the hydrogen conduit, or both are fluidly connected to the mixing conduit at an injection point, and wherein the mixing conduit has an average interior cross-sectional area. The method includes mixing the hydrogen gas and the combustible carrier gas within the mixing conduit downstream of the injection point, whereby a tuyere input gas is formed. The method further includes supplying the tuyere input gas to a supply ring fluidly connected to the mixing conduit offset an injection length relative to the injection point of the mixing conduit, and supplying the tuyere input gas to the plurality of tuyeres via the supply ring, wherein a mixing ratio is equal to the injection length divided by the average interior cross-sectional area of the mixing conduit, and wherein the mixing ratio is greater than 3.5.
[0032] As shown and described herein, an exemplary apparatus for smelting iron ore includes a blast furnace having a furnace body. There are a plurality of tuyeres connected with the furnace body and configured to deliver a tuyere input gas to the blast furnace. The tuyere input gas comprises a mixture of hydrogen gas and a combustible carrier gas. The apparatus further includes a supply ring connected with the plurality of tuyeres and configured to deliver the tuyere input gas to the plurality of tuyeres. There is a mixing conduit connected with the supply ring and configured to deliver the tuyere input gas to the supply ring. A carrier gas conduit connects with the mixing conduit and is configured to deliver the combustible carrier gas to the mixing conduit. A hydrogen gas conduit connects with the mixing conduit and is configured to deliver the hydrogen gas to the mixing conduit. With the apparatus, the tuyere input gas is delivered to the plurality of tuyeres at an equal rate across each tuyere of the plurality of tuyeres.
[0033] It should be understood that any one or more of the teachings, embodiments, examples, etc. described herein may be combined with any one or more of the other teachings, embodiments, examples, etc. that are described herein. The following-described teachings, embodiments, examples, etc. should therefore not be viewed in isolation relative to each other. Various suitable ways in which the teachings herein may be combined will be readily apparent to those of ordinary skill in the art in view of the teachings herein. Such modifications and variations are intended to be included within the scope of the claims.
[0034] Having shown and described various examples of the present invention, further adaptations of the methods and systems described herein may be accomplished by appropriate modifications by one of ordinary skill in the art without departing from the scope of the present invention. Accordingly, the scope of the present invention should be considered in terms of the following claims and is understood not to be limited to the details of structure and operation shown and described in the specification and drawings.
Claims
I / We claim:
1. A method for operating a blast furnace comprising a plurality of tuyeres, the method comprising:(a) supplying a hydrogen gas via a hydrogen conduit to a mixing conduit;(b) supplying a combustible carrier gas via a carrier gas conduit to the mixing conduit, wherein the carrier gas conduit, the hydrogen conduit, or both are fluidly connected to the mixing conduit at an injection point;(c) mixing the hydrogen gas and the combustible carrier gas within the mixing conduit downstream of the injection point, whereby a tuyere input gas is formed; (d) supplying the tuyere input gas to a supply ring fluidly connected to the mixing conduit having an injection length relative to the injection point of the mixing conduit, and wherein the mixing conduit has an average interior diameter averaged over the injection length; and(e) supplying the tuyere input gas to the plurality of tuyeres via the supply ring, wherein an offset ratio is equal to the injection length divided by the average interior diameter of the mixing conduit, and wherein the offset ratio is greater than 20.
2. The method of claim 1, further comprising heating the hydrogen gas, the combustible carrier gas, or both prior to mixing the hydrogen gas and the combustible carrier gas within the mixing conduit.
3. The method of claim 1, wherein the combustible carrier gas is natural gas.
4. The method of claim 1, wherein the tuyere input gas comprises up to 20% hydrogen gas by volume.
5. The method of claim 1, wherein the tuyere input gas is delivered at an equal rate across each tuyere of the plurality of tuyeres.
6. The method of claim 1, further comprising using a double-block and bleed valve system to selectively isolate the hydrogen gas from the combustible carrier gas and to control a volume flow rate of hydrogen.
7. The method of claim 1, wherein a flow rate of hydrogen gas supplied to the mixing conduit is based on a temperature or other sensors at or in front of one or more tuyeres of the plurality of tuyeres.
8. The method of claim 1, wherein the mixing conduit has at least two bends.
9. The method of claim 8, wherein a cumulative total of angles of the bends of the mixing conduit is greater than or equal to 180°.
10. An apparatus for smelting iron ore comprising:(a) a blast furnace having a furnace body;(b) a plurality of tuyeres connected with the furnace body and configured to deliver a tuyere input gas to the blast furnace, wherein the tuyere input gas comprises a mixture of hydrogen gas and a combustible carrier gas;(c) a supply ring connected with the plurality of tuyeres and configured to deliver the tuyere input gas to the plurality of tuyeres;(d) a mixing conduit connected with the supply ring and configured to deliver the tuyere input gas to the supply ring;(e) a carrier gas conduit connected with the mixing conduit and configured to deliver the combustible carrier gas to the mixing conduit; and(f) a hydrogen gas conduit connected with the mixing conduit and configured to deliver the hydrogen gas to the mixing conduit, wherein the tuyere input gas is delivered to the plurality of tuyeres at an equal rate across each tuyere of the plurality of tuyeres.
11. The apparatus of claim 10, wherein an offset ratio is equal to an injection length divided by an average interior diameter obtained by averaging over the injection length of the mixing conduit, and the offset ratio is greater than 20.
12. The apparatus of claim 10, further comprising a double-block and bleed valve configured to isolate the hydrogen gas from the combustible carrier gas.
13. The apparatus of claim 10, wherein the combustible carrier gas is a natural gas.
14. The apparatus of claim 10, further comprising a heater configured to heat the hydrogen gas before mixing with the combustible carrier gas at the mixing conduit.
15. The apparatus of claim 10, wherein a flow of the hydrogen gas to the mixing conduit is regulated based on a temperature or other sensors at or in front of one or more tuyeres of the plurality of tuyeres.
16. The apparatus of claim 10, wherein the tuyere input gas comprises up to 20% hydrogen gas by volume.
17. The apparatus of claim 10, wherein the tuyere input gas comprises up to 95% hydrogen gas by volume.
18. The apparatus of claim 10, further comprising one or more sensors and a control unit configured to control one or more of the hydrogen gas flow, the combustible carrier gas flow, and the tuyere input gas flow.
19. The apparatus of claim 18, wherein the control unit is configured to adjust the ratio of the hydrogen gas to the combustible carrier gas based on real-time measurements of conditions within the blast furnace based on the one or more sensors.
20. The apparatus of claim 18, wherein the one or more sensors are configured to detect a gas leak and the control unit in response to the leak detection automatically isolates the hydrogen gas supply.
21. A method for operating a blast furnace comprising a plurality of tuyeres, the method comprising:(a) supplying a hydrogen gas via a hydrogen conduit to a mixing conduit;(b) supplying a combustible carrier gas via a carrier gas conduit to the mixing conduit, wherein the carrier gas conduit, the hydrogen conduit, or both are fluidly connected to the mixing conduit at an injection point;(c) mixing the hydrogen gas and the combustible carrier gas within the mixing conduit downstream of the injection point, whereby a tuyere input gas is formed; (d) supplying the tuyere input gas to a supply ring fluidly connected to the mixing conduit offset an injection length relative to the injection point of the mixing conduit, and wherein the mixing conduit has an average interior diameter averaged over the injection length; andsupplying the tuyere input gas to the plurality of tuyeres via the supply ring.
22. The method of claim 21, wherein an offset ratio is equal to the injection length divided by the average interior diameter of the mixing conduit, and wherein the offset ratio is greater than 20.
23. The method of claim 21, wherein an offset ratio is equal to the injection length divided by the average interior diameter of the mixing conduit, and wherein the offset ratio is greater than 25.
24. The method of claim 21, wherein an offset ratio is equal to the injection length divided by the average interior diameter of the mixing conduit, and wherein the offset ratio is greater than 50.
25. The method of claim 21, wherein an offset ratio is equal to the injection length divided by the average interior diameter of the mixing conduit, and wherein the offset ratio is greater than 70.
26. The method of any of claims 21 to 25, further comprising heating the hydrogen gas prior to mixing the hydrogen gas and the combustible carrier gas within the mixing conduit.
27. The method of any of claims 21 to 26, wherein the combustible carrier gas is a natural gas.
28. The method of any of claims 21 to 27, wherein the tuyere input gas comprises up to 20% hydrogen gas by volume.
29. The method of any of claims 21 to 27, wherein the tuyere input gas comprises up to 50% hydrogen gas by volume.
30. The method of any of claims 21 to 27, wherein the tuyere input gas comprises up to 80% hydrogen gas by volume.
31. The method of any of claims 21 to 27, wherein the tuyere input gas comprises up to 95% hydrogen gas by volume.
32. The method of any of claims 21 to 31, wherein the tuyere input gas is delivered at an equal rate across each tuyere of the plurality of tuyeres.
33. The method of any of claims 21 to 32, further comprising using a double-block and bleed valve to selectively isolate the hydrogen gas from the combustible carrier gas.
34. The method of any of claims 21 to 33, wherein a flow rate of hydrogen gas supplied to the mixing conduit is based on a temperature at one or more tuyeres of the plurality of tuyeres.
35. The method of any of claims 21 to 34, wherein the mixing conduit has at least two bends.
36. The method of any of claims 21 to 35, wherein a cumulative total of angles of the bends of the mixing conduit is greater than or equal to 180°.
37. The apparatus of claim 10, wherein an offset ratio is equal to an injection length divided by an average interior diameter of the mixing conduit, and the offset ratio is greater than 25.
38. The apparatus of claim 10, wherein an offset ratio is equal to an injection length divided by an average interior diameter of the mixing conduit, and the offset ratio is greater than 50.
39. The apparatus of claim 10, wherein an offset ratio is equal to an injection length divided by an average interior diameter of the mixing conduit, and the offset ratio is greater than 70.
40. The apparatus of any of claims 10 - 11 and 37-39, further comprising a double-block and bleed valve configured to isolate the hydrogen gas from the combustible carrier gas.
41. The apparatus of any of claims 10 - 11 and 37-40, wherein the combustible carrier gas is a natural gas.
42. The apparatus of any of claims 10 - 11 and 37-41, further comprising a heater configured to heat the hydrogen gas before mixing with the combustible carrier gas at the mixing conduit.
43. The apparatus of any of claims 10 - 11 and 37-42, wherein a flow of the hydrogen gas to the mixing conduit is regulated based on a temperature at one or more tuyeres of the plurality of tuyeres.
44. The apparatus of any of claims 10 - 11 and 37-43, wherein the tuyere input gas comprises up to 20% hydrogen gas by volume.
45. The apparatus of any of claims 10 - 11 and 37-43, wherein the tuyere input gas comprises up to 95% hydrogen gas by volume.
46. The apparatus of any of claims 10 - 11 and 37-45, further comprising one or more sensors and a control unit configured to control one or more of the hydrogen gas flow, the combustible carrier gas flow, and the tuyere input gas flow.
47. The apparatus of claim 46, wherein the control unit is configured to adjust the ratio of the hydrogen gas to the combustible carrier gas based on real-time measurements of conditions within the blast furnace based on the one or more sensors.
48. The apparatus of any of claims 10 - 11 and 37-47, wherein the one or more sensors are configured to detect a gas leak and the control unit in response to the leak detection automatically isolates the hydrogen gas supply.