Gas injector for shaft injection in blast furnaces

Abstract

An injector for injecting hot gases, particularly heated reducing gases, into a furnace or reactor includes a tubular body (12) extending along a major axis (L) between a mounting portion (18) configured to secure the injector to the furnace and a nose portion (14) to be disposed within the furnace, the tubular body including an inner gas passage (20) for directing heated gas from an inlet orifice (22) in the mounting portion to at least one outlet orifice (16) in the nose portion. The tubular body (12) includes supply and return coolant channels (40 and 42) defined between cooperating inner and outer tubes (30 and 34), the supply and return coolant channels being formed as intertwined helical channels extending in the same layer along the major axis.

Description

[Technical Field]

[0001] The present invention relates generally to the field of metallurgy, and more particularly to the operation of a shaft furnace, or blast furnace, in which hot reducing gas is supplied to the furnace shaft. [Background technology]

[0002] The Paris Agreement and near-global consensus on the need to take action on emissions make it imperative for each industry sector to consider developing solutions to improve energy efficiency and reduce CO2 emissions.

[0003] In this context, actors in the field of ferrous metallurgy have developed new approaches to reduce the environmental footprint of the blast furnace iron production route. Indeed, despite alternative methods such as scrap melting or direct reduction in electric arc furnaces, the blast furnace (BF) remains today the most widely used process for steel production.

[0004] One technique that has been developed to reduce the carbon footprint during steel production is so-called "shaft injection", where hot gases (mainly CO and H) are injected into the upper part of the blast furnace, above the cohesive zone, in a section that is generally protected internally by a refractory lining or cooling elements such as plates or staves or plate coolers, or by cooling elements that protrude on the inner wall of the furnace.

[0005] This injection of hot gases into the blast furnace at shaft level (shaft injection) or into the shaft furnace has been cited in many publications and inventions, but industrial application has not yet been implemented for commercial blast furnaces.

[0006] A gas injector for shaft supply is disclosed, for example, in US Pat. No. 5,649,399. The gas injector comprises a tubular body defining a gas flow path, and a coolant fluid is circulated in an annular gap.

[0007] Other injector designs have been developed without cooling configurations (see, for example, U.S. Patent No. 5,929,393). However, injectors without cooling do not achieve the higher strength of materials used at lower temperatures and also result in larger dimensions.

[0008] Furthermore, prior art injectors are molded from expensive, premium materials and are subjected to differential (thermally induced) stresses at many points along their body during use, causing some portions of the injector body to exhibit different stress-related expansion / distance than others, thereby reducing the life and reliability of the injector.

[0009] Therefore, one challenge is to increase the durability and versatility of injectors that operate in aggressive gas atmospheres, in abrasive conditions with solid material flow at very high temperatures, and in dusty environments. Summary of the Invention [Problem to be solved by the invention]

[0010] SUMMARY OF THE INVENTION It is an object of the present invention to provide a gas injector of improved design which overcomes the above-mentioned drawbacks and meets the desired requirements of durability and versatility. [Means for solving the problem]

[0011] In order to achieve the above object, the present invention proposes an injector for injecting hot gas, in particular hot reducing gas, into a furnace or reactor, more particularly into a metallurgical furnace or reactor, in particular into a shaft furnace or blast furnace, the gas injector being specially developed for injecting hot gas, i.e. hot / heated reducing gas, into the furnace or reactor, more particularly into a shaft furnace or blast furnace. a tubular body extending along a major axis between a mounting portion configured to secure the injector to a furnace and a nose portion disposed inside the furnace, the tubular body comprising an internal gas passage for directing hot gas (particularly heated reducing gas) from an inlet orifice in the mounting portion to at least one outlet orifice in the nose portion; The tubular body includes supply and return coolant channels defined between cooperating inner and outer tubes, the supply and return coolant channels being formed as intertwined helical channels extending in a major axis direction within the same layer.

[0012] The main advantage of the present invention is achieved by arranging the supply and return coolant channels in the same layer. Such an arrangement is possible due to the specific design of the injector of the present invention, where the inner and outer tubes cooperate to define the supply and return channels. The supply and return channels are intertwined, that is, they are adjacent to each other in the same layer, and therefore at the same level.

[0013] The design of the present invention is compact, and combining the supply and return channels in the same layer is more compact than having, for example, two overlapping layers (one for the supply flow and one for the return flow), thereby either providing more space for the passage of reducing gas through the injector or reducing the overall outer dimensions of the injector, particularly the outer diameter.

[0014] Another advantage of the present invention is that the supply and return coolant channels cool the injector, increasing its resistance to wear and reliability in the event of a sudden charge drop. Because the coolant channels are intertwined, both coolant flows are arranged next to each other. In other words, the channels through which the coolant flows in opposite directions are staggered. Due to the present invention's configuration of the supply and return coolant channels formed as intertwined spiral channels, the surface of the injector of the present invention is cooled more uniformly than the surface of a conventional injector with a conventional cooling configuration, thereby reducing thermal stress in the material forming the tube and therefore reducing deformation of the injector. This provides the gas injector with the desired durability and versatility.

[0015] Any suitable material may be used for the injector tubular body. However, the injector body (i.e., the inner and outer tubes) is preferably made of steel or alloy steel (or steel alloy), more preferably stainless steel or high-temperature steel. High-temperature steel corresponds to steel that is resistant to corrosion at high temperatures and maintains its strength at higher temperatures than conventional steels. High-temperature steel may be, for example, the following steel grades: 1.4841; 1.5415; 1.4842; 1.4659; 1.4859; 1.4889 or similar. Alternatively, the injector body may be made of copper, a copper alloy, nickel, or a nickel alloy.

[0016] In an embodiment, the inner tube comprises two intertwining spiral grooves that define a supply channel and a return channel, the spiral grooves extending from the mounting portion to the nose portion, and the two spiral grooves being fluidly connected at the nose portion.

[0017] Furthermore, an inlet port is arranged in the mounting portion connecting the first spiral groove, and an outlet port is arranged in the mounting portion connecting the second spiral groove. The inlet and outlet ports are advantageously connected to a coolant circulation system. Coolant (e.g., water) from a coolant source enters the first spiral groove through the inlet port, flows through the first groove towards the nose portion where the first and second grooves are connected, and then flows back through the second spiral groove towards the mounting portion where the coolant exits the second groove through the outlet port (towards a collector duct).

[0018] One advantage of the present invention relates to the size of the injector. As mentioned above, due to the specific design in which the supply coolant channel and the return coolant channel are arranged in the same layer, the overall outer diameter of the injector of the present invention can be small / compact, allowing more space for the passages. This is achieved by the specific design of the injector of the present invention, in which the ratio of the outer diameter of the outer tube to the inner diameter of the inner tube is preferably less than 2.5, less than 2, or even less than 1.5. For example, in embodiments, the outer and inner diameters can be dimensioned as follows: 220 / 110 mm, 270 / 160 mm, 250 / 135 mm. These values ​​are merely indicative and do not limit the scope of the present disclosure.

[0019] In an embodiment, the nose portion comprises an end face in which the at least one outlet orifice is located, the end face being at least partially inclined relative to the main axis such that the end face is oriented downwards in use. Advantageously, the inclined end face prevents the descending charge from entering the injector, thereby reducing the risk of blockage or flow restriction of the injector.

[0020] Furthermore, the inclined end faces advantageously facilitate uniform cooling of the nose portion of the injector of the present invention, in which the supply and return coolant channels are formed in the same layer, when the supply channels close to the tip of the nose can follow the tip at a short, substantially constant distance. This advantageously results in uniform cooling when the coolant cannot take shortcuts, in contrast to what is known in the art, such as that of FR 2 085 511, where the water flow is smaller at the top because the path for the water is longer and therefore the resistance is higher.

[0021] The end face may be flat or curved. Preferably, the angle between the end face and the main axis is between 10° and 60°, more preferably 20°. However, the angle may be adapted depending on the response angle of the material in the furnace and the size of the injector.

[0022] According to the same or another embodiment, the injector includes a sealing arrangement between the inner and outer tubes. Preferably, the sealing arrangement includes a spiral seal interposed between two spiral grooves. In other words, the supply and return coolant channels are separated from each other by a seal disposed in the space extending between the two channels. Such a location of the seal advantageously reduces bypass of coolant from one channel to the other, even if the outer tube deforms during operation. The spiral seal may include any suitable material, but preferably includes a water-swellable material, more preferably a water-swellable fiber. If one channel begins to leak, the coolant (typically water) contacts the water-swellable material, which advantageously expands to close the forming gap, thereby preventing further leakage of the coolant.

[0023] According to the same or other embodiments, the injector further comprises a tubular protective insert disposed in the passage of the tubular body and defining a central flow path for the reducing gas. The insert protects the inner surface of the inner tube, thereby increasing its lifespan and efficiency. The protective insert is disposed within the passage and defines a central flow path for the heated reducing gas.

[0024] The protective insert may be made of any suitable material, but is preferably made of a thermally insulating and / or stress-resistant and / or chemically resistant material. More preferably, the insert is made of a ceramic and / or high-density ceramic material, such as alumina, magnesia, zirconia, or silicon carbide.

[0025] Advantageously, an insulating material can be disposed between the tubular body and the protective insert. This reduces the temperature loss of the injected hot reducing gas, leading to higher gas reactivity and energy savings. In an embodiment, the tubular protective insert has a concave outer surface, and the insulating material is provided as an outer layer on the concave outer surface. The insulating material can be provided in any desired shape and can be supplied as one, two, or several pieces that can be formed / assembled into an outer layer around the tubular protective insert. In a preferred embodiment, the insulating material is provided as two half-cylinders that fit within the concave outer surface of the protective insert. The insulating material can generally be any material with insulating properties, preferably comprising an alumina-based or zirconia-based ceramic material, more preferably a microporous ceramic and / or ceramic fiber.

[0026] In an embodiment, the injector further comprises a mounting flange extending radially from the tubular body for at least indirectly securing the injector to the outer furnace wall.

[0027] According to the same or other embodiments, the injector further comprises a connection flange surrounding the mounting portion for connecting the injector to a corresponding flange of a reducing gas supply pipe of a metallurgical furnace gas injection system.

[0028] According to another aspect, the present invention also relates to a gas injection system for a furnace, in particular a blast furnace, comprising a furnace wall (or shell) at least partially covered with an inner protective layer, the gas injection system comprising at least one injector according to the present invention, which injector traverses the furnace wall and the protective layer, respectively. Conventionally, the protective layer may comprise refractory material and / or cooling elements. The cooling elements may comprise cooling boxes and / or cooling panels / cooling staves.

[0029] For cooling staves with internal coolant channels, the inventive design with single layer coolant channels is advantageous for its compactness, as the injectors can be located within the plate body of the stave, between the coolant channels or adjacent to the coolant channels.

[0030] The injector may be positioned through the outer wall and protective layer so that the injector tip is flush with the inner surface of the protective layer (facing the charge / charge material) or protrudes therefrom, in the latter case protruding from the inner surface of the protective layer by a distance of, for example, 50, 100, or 200 mm, or possibly more.

[0031] In an embodiment, the injector is oriented perpendicular to the furnace wall (i.e., pointing toward the center of the furnace) or tangentially. In a preferred embodiment, the angle between the injector and the furnace wall is between 50° and 90°. Angles less than 50° can cause space problems inside the furnace. A tangential orientation helps to create a swirl flow within the furnace, which helps to increase gas distribution and mixing with gas rising from the tuyere level, and also increases the residence time of the gas within the furnace, thus improving gas utilization.

[0032] According to the same or another embodiment, the gas injection system further comprises at least one guide sleeve, which is fixed to the furnace wall and traverses the furnace wall and the staves. The injector is received in the guide sleeve and protrudes from the guide sleeve into the furnace. Advantageously, this sleeve protects the cooling elements of the furnace during the replacement of the injector during operation. The guide sleeve prevents the descending charge from being trapped between the injector and the stave during the replacement process, reducing the risk of major damage.

[0033] The gas injection system may further include at least one mounting sleeve secured to the furnace wall and projecting into the interior of the furnace, the guide sleeve extending within the mounting sleeve.

[0034] According to yet another aspect, the present invention also relates to a shaft furnace, in particular a blast furnace, comprising: a metal shell defining a furnace wall; at least one tuyere located at tuyere level for injecting hot gas into the shaft furnace; a gas injection system according to the present invention comprising at least one injector, At least one injector is positioned at an injection level above the tuyere level.

[0035] It should be noted that the present injector can be used in a variety of shaft / blast furnace operating modes.

[0036] The hot reducing gas may generally be a gas containing mainly (>50% by volume) CO or reducing agent species such as H. In particular, the reducing gas may be "synthesis gas." The reducing gas may be injected into the furnace via an injector at a temperature comprised between 600 and 1200°C, in particular between 800 and 1200°C. The reducing gas injection may be carried out at a velocity between 40 and 200 m / s.

[0037] Injection of hot reducing gas is typically accomplished using multiple injectors according to the present disclosure, which are distributed circumferentially around the shaft / blast furnace, preferably within a distance of 0.5 to 2.5 meters between injectors. Such evenly spaced injectors allow for even distribution of injected gas around the furnace periphery and further help to concentrate rising gases coming up through the furnace from the bosh region.

[0038] Conventionally, the gas injected through the tuyere at tuyere level can be hot air to combust the coke in the charge. Alternatively, a hot reducing gas (e.g., synthesis gas) can be injected through the tuyere at a relatively high temperature, with or without oxygen. [Brief explanation of the drawings]

[0039] The invention will now be described, by way of example only, with reference to the accompanying drawings, in which: [Figure 1] 1 is a first perspective schematic view of one embodiment of an injector of the present invention; FIG. [Figure 2] FIG. 2 is a second perspective schematic view of the injector of the present invention. [Figure 3] FIG. 3 is a cross-sectional schematic view of the injector of FIG. 2. [Figure 4] FIG. 3 is a detailed perspective schematic view of a portion of the injector of FIG. 2. [Figure 5] FIG. 3 is an exploded perspective schematic view of the injector of FIG. 2. DETAILED DESCRIPTION OF THE INVENTION

[0040] 1-5 show different views of one embodiment of an injector 10 according to the present disclosure.

[0041] The gas injector 10 is designed to inject heated reducing gas into furnaces, particularly blast furnaces, but can be used to inject hot gas into furnaces or reactors in general, particularly metallurgical furnaces / reactors. The injector 10 comprises a tubular body 12 (or injector body) extending along a major axis L from a nose (front) portion 14 having, for example, one injection hole or exit orifice 16 (or more) to an opposite (rear) mounting portion 18. The tubular body 12 includes an internal gas passage 20 for conducting hot / heated reducing gas from an inlet orifice 22 in / at the mounting portion 18 to the injection hole 16. The tubular body 12 is typically made of steel or a steel alloy or metal alloy. In practice, the inlet orifice 22 is coupled to a source of hot gas, i.e., hot reducing gas (not shown), via appropriate piping / ducting.

[0042] Mounting portion 18 includes a mounting flange 24 extending radially from tubular body 12 for at least indirectly mounting, i.e., securing, injector 10 to a furnace wall portion, typically the furnace outer wall / shell (not shown). Mounting portion 18 further includes a connection flange 26 extending radially from tubular body 12 and surrounding inlet opening 22 for connecting the injector to a corresponding flange of a reducing gas supply pipe of a gas injection system (not shown). Other types of connection means for connecting inlet orifice 22 of injector 10 to the supply piping may also be used.

[0043] The injector 10 or its tubular body 12, particularly if the portion of the injector 10 surrounding the injection hole or exit orifice 16 in the installed state protrudes inside the blast furnace, is provided with a cooling system 28, such as cooling channels connected to a coolant circulation system (not shown).

[0044] It should be understood that the injector 10 of the present invention has a tubular body 12 comprised of two tubes: an inner tube 30 and an outer tube 34. As can be seen, the outer tube 34 defines the outer wall of the injector, while the inner tube 30 defines the gas passageway 20.

[0045] The tubular body 12 includes supply and return coolant channels 40 and 42 defined between the inner and outer tubes 30 and 34. The supply and return channels 40 and 42 are formed as intertwined spiral channels extending in a main direction (defined by axis L) within the same layer. The supply channel 40 extends from an inlet port 44 in the mounting portion 18 to the nose 14 of the tubular body 12, and the return channel 42 extends from the nose portion 14 to an outlet port 46 in the mounting portion 18 of the tubular body 12. The inlet and outlet ports 44 and 46 open through the outer tube 34. The supply and return channels 40 and 42 are fluidly connected to each other at the nose portion 14. As can be seen from the drawing, because the supply and return channels are intertwined, they are positioned next to each other within the same layer. Thus, they are at the same level, and the supply and return channels extend adjacent to each other throughout the length of the tubular body 12, forming a single-layer structure.

[0046] In other words, the supply and return channels are bounded laterally (across major axis L) by the inner and outer tubes 30, 34. The supply and return channels are two separate flow paths for the coolant that are intertwined or alternating (i.e., not one above the other) within the same layer defined by the inner and outer tubes 30, 34. The supply and return channels surround the gas passage 20.

[0047] The inner tube 30 and outer tube 34 are shaped / configured to cooperate with one another to define the supply coolant channel 40 and the return coolant channel 42. In the illustrated embodiment, the outer surface 50 of the inner tube 30 includes two intertwining spiral grooves 48.1, 48.2 that define the supply coolant channel 40 and the return coolant channel 42, respectively, separated by a helical ridge 48.3. In such an embodiment, the inner surface 52 of the outer tube 34 is smooth, closing the coolant channels. However, other configurations are possible; for example, the outer surface of the inner tube 30 may be smooth, while the inner surface of the outer tube 34 may be machined to include two intertwining spiral grooves.

[0048] A sealing arrangement is provided between the inner tube 30 and the outer tube 34 of the tubular body 12. According to the embodiment of FIG. 4, the sealing arrangement comprises a helical seal 54 interposed between two helical grooves 48.1, 48.2. The seal 54 is disposed within the groove of the helical ridge 48.3. The seal 54 may generally be made from any suitable material, although a water-swellable material, such as a water-swellable fiber, is preferred. The inner and outer tubes are assembled in a fixed, sealed manner relative to one another. For example, the inner and outer tubes can be welded at their axial ends, which also provides the desired water seal.

[0049] The nose portion 14 of the injector tubular body 12 further comprises an end face 56 in which the exit orifice 16 is disposed. The end face 56 is inclined relative to the major L axis such that an angle θ is formed between the end face 56 and the major L axis, such that the end face faces downward in use. The angle θ may be, for example, between 10° and 60°. According to the illustrated embodiment, the end face 56 is flat, although other configurations are possible, and the end face may, for example, be curved.

[0050] In use, the injector 10 is exposed to considerable heat inside the furnace. Therefore, a protective insert 60, which acts as an insulating layer, preferably ceramic or refractory, is advantageously disposed inside the inner tube 30 and thus in the passage 20 of the tubular body 12. The protective insert 60 is of tubular / cylindrical shape and protects the inner surface of the inner tube 30 while leaving a central passage 20.1 for the flow of reducing gas through the injector. The outer diameter of the protective insert 60 is generally sized to correspond, with some clearance, to the inner diameter of the inner tube 30 of the tubular body 12. The protective insert 60 may generally be made of ceramic or a high-density ceramic, such as an oxide ceramic, in particular magnesia, alumina, zirconia, or silicon carbide.

[0051] An intermediate layer of insulating material 64 can be disposed between the inner tube 30 and the protective insert 60. In this variant, the outer surface of the protective insert includes a recess 62, i.e., the insert 60 has a concave outer surface, and the insulating material 64 is disposed within the recess 62. As can be seen in FIG. 5, the protective insert has a tubular shape with two end shoulders 61 on its outer surface that axially separate the annular recess 62. The insulating material 64 is configured as two semi-cylinders 64.1, 64.2 that fit within the annular recess 62 on the outer surface of the protective insert 60 (FIG. 5). However, other configurations are also possible, and the insulating material can be provided in any other shape, such as a cylindrical sleeve, with the protective insert inserted inside the sleeve-shaped insulating material. The insulating layer can be made of any suitable insulating material, such as an oxide ceramic.

[0052] In its installed state, the injector 10 is positioned so that it protrudes slightly into the interior of the blast furnace, as shown in FIG. 1 . A blast furnace conventionally comprises a hearth and a shaft-forming steel shell 71 (shown in dashed lines) extending vertically above the hearth. The steel shell constitutes the furnace outer wall. Its inner surface (i.e., toward the interior of the furnace) is generally covered with a cooling plate (or stave). Such cooling plates typically have a slab-shaped body made of steel or copper (alloy) with internal coolant channels through which coolant (water) circulates. The front surface of the cooling plate (i.e., facing the interior of the furnace) is also generally covered with a steel blade insert or a protective layer of refractory material (not shown). The dashed line 73 in FIG. 1 indicates the inner surface of the protective lining formed by the cooling plate, with or without the insert / refractory material, for example, and LP indicates the protruding length, which may be approximately 50, 100, or 200 mm or more.

[0053] The mounted injector 10 protrudes inside the furnace through a corresponding opening in the shell so that the nose part 14 with the outlet orifice 16 is located inside the furnace, while the mounting part 18 is outside the outer wall. If cooling plates are present, these are provided with corresponding openings (holes through the thickness of the cooling plates) and the injector is placed through these openings. The injector body 12 extends through openings in the furnace shell (opening 71.1) and the cooling plate (protective lining 71) and protrudes from the cooling plate inside the furnace (over a length LP).

[0054] The injector 10 is hermetically mounted in the opening 71.1 of the furnace shell 71 by means of a mounting flange 24. To facilitate installation and sealing purposes, a mounting sleeve 66 (made of steel, ceramic material, or a suitable metal alloy) can be arranged to extend into the two openings. The mounting sleeve 66 has an outer diameter corresponding to the diameters of the two openings (i.e., those of the outer shell and the cooling plate) and a length adapted to lead through the shell 71. The mounting sleeve 66 has a respective mounting flange 68 that is fixed to the furnace wall in any suitable manner (e.g., hermetically bolted or welded).

[0055] Guide sleeves 70, each having a flange 72, may be further secured to the outer furnace wall and arranged to extend through the furnace wall and protective lining (cooling elements and / or refractory). Guide sleeves 70 extend into mounting sleeve 66 and receive injectors 10 that protrude therefrom into the furnace. Guide sleeves 70 supply gas to a length corresponding to the distance from the outer surface of the shell to front surface 71 or the protective lining.

[0056] The injector 10 can be mounted to the furnace wall in any suitable manner. The injector can be oriented perpendicular to the furnace wall (pointing towards the center of the furnace) or tangentially (i.e., at any angle below 90°, preferably above 50° relative to the furnace wall at the location of the injector). [Explanation of symbols]

[0057] 10 Injector 12 Tubular body 14 Nose part 16 Exit Orifice 18 Mounting part 20 Gas passage 22 inlet orifice 24 Injector mounting flange 26 Connection flange 28 Cooling System 30 Inner tube 34 Outer tube 40 supply coolant channels 42 return coolant channel 44 Inlet Port 46 Exit Port 48.1, 48.2 Interlaced spiral groove 48.3 Spiral ridge 50 Outer surface of inner tube 52 Inner surface of outer tube 54 Spiral Seal 56 End face 60 Protective Inserts 61 End shoulder 62 recess 64 Insulation Layer 64.1, 64.2 Half of the insulation 66 Mounting sleeve 68 Mounting sleeve flange 70 Guide sleeve 72 Guide sleeve flange L spindle θ angle between the end face and the main axis [Prior art documents] [Patent documents]

[0058] [Patent Document 1] International Publication No. 2022 / 064046 [Patent Document 2] International Publication No. 2022 / 058771

Claims

1. An injector for injecting high-temperature gas into a metallurgical furnace or reactor, particularly for injecting heated reducing gas into a furnace or reactor, A tubular body (12) extending along a main axis (L) between a mounting portion (18) configured to fix the injector to the furnace and a nose portion (14) to be positioned inside the furnace, wherein the tubular body (12) comprises an internal gas passage (20) for guiding heated gas from an inlet orifice (22) of the mounting portion to at least one outlet orifice (16) of the nose portion, An injector wherein the tubular body (12) includes a supply coolant channel (40) and a return coolant channel (42) defined between a cooperating inner tube (30) and an outer tube (34), and the supply coolant channel and the return coolant channel are formed as entangled helical channels extending in the direction of the main axis within the same layer.

2. The inner tube comprises two interlocking helical grooves (48.1, 48.2) defining the supply channel and the return channel, the helical grooves extending from the mounting portion to the nose portion, and the two helical grooves being fluidly connected at the nose portion. The inlet port (44) is positioned in the mounting portion that connects the first helical groove, The injector according to claim 1, wherein the outlet port (46) is located in the mounting portion that connects the second helical groove.

3. The injector according to claim 1, wherein the ratio of the outer diameter of the outer tube to the inner diameter of the inner tube is less than 2.5, preferably less than 2 or 1.

5.

4. The injector according to claim 1, wherein the nose portion (14) comprises an end face (56) on which the at least one outlet orifice is located, and the end face is at least partially inclined with respect to the spindle such that the end face faces downward when in use.

5. The injector according to claim 4, wherein the end face (56) is flat or curved.

6. The injector according to claim 4, wherein the angle (θ) between the end face and the main shaft is between 10° and 60°, and preferably 20°.

7. The injector according to any one of claims 1 to 6, comprising a sealing configuration between the inner tube and the outer tube.

8. The injector according to claim 7, wherein the sealing configuration comprises a helical seal (54) interposed between the two helical grooves.

9. The injector according to claim 8, wherein the helical seal comprises a water-swellable material, preferably a water-swellable fiber.

10. The injector according to any one of claims 1 to 6, further comprising a tubular protective insert (60) disposed in the passage of the tubular body.

11. The injector according to claim 10, wherein the protective insert is made of a thermal insulation material and / or a stress-resistant material and / or a chemical-resistant material, preferably the insert is made of an oxide ceramic, graphite, and / or silicon carbide.

12. The injector according to claim 10, wherein the heat insulating material (64) is disposed between the tubular body (12) and the protective insert (60).

13. The injector according to claim 12, wherein the tubular protective insert has a concave outer surface, and the heat insulating material is provided on the concave outer surface as a peripheral layer.

14. The injector according to claim 13, wherein the heat insulating material is provided as two semi-cylindrical (64.1, 64.2) that fit into the concave outer surface.

15. The injector according to claim 12, wherein the heat insulating material preferably includes alumina-based ceramic or zirconia-based ceramic as microporous ceramic and / or ceramic fibers.

16. The injector according to any one of claims 1 to 6, further comprising a mounting flange (24) extending radially from the tubular body for fixing the injector to the outer wall of the furnace at least indirectly.

17. The injector according to any one of claims 1 to 6, further comprising a connecting flange (26) surrounding the mounting portion for connecting the injector to a corresponding flange of a reducing gas supply pipe of a metallurgical furnace gas injection system.

18. The injector according to any one of claims 1 to 6, wherein the injector body is made of steel or alloy steel, preferably stainless steel or high-temperature steel.

19. A gas injection system for a furnace or reactor, particularly a blast furnace, comprising a furnace wall (71) having a protective layer, wherein the gas injection system comprises at least one injector as described in claim 1, the injector traversing the furnace wall and the protective layer.

20. The gas injection system according to claim 19, wherein the injector is oriented perpendicular or tangentially to the furnace wall, and preferably the angle between the injector and the furnace wall is between 50° and 90°.

21. The gas injection system according to claim 19, further comprising at least one guide sleeve (70), the guide sleeve being fixed to the furnace wall and traversing the furnace wall and the staves, the injector being received within the guide sleeve and protruding from the guide sleeve within the furnace.

22. The gas injection system according to claim 21, further comprising at least one mounting sleeve (68) fixed to the furnace wall and protruding inside the furnace, wherein the guide sleeve extends within the mounting sleeve.

23. The gas injection system according to claim 19, wherein the supply coolant channel is connected to a coolant fluid supply source and the return coolant channel is connected to a coolant collector duct.

24. The gas injection system according to claim 19, wherein the protective layer includes a cooling element and / or a refractory material, and the gas injector is positioned such that the nose portion is on the same plane as the inner surface of the protective layer or protrudes from the protective layer by a certain distance (PL).

25. Shaft furnaces, especially blast furnaces, A metal shell that defines the furnace wall, At least one tuyere positioned at the tuyere level for injecting high-temperature gas into the shaft furnace, A gas injection system according to any one of claims 19 to 24, A shaft furnace in which at least one of the injectors is positioned at an injection level above the tuyere level.

Images