Shaft furnaces and process gas injectors for shaft furnaces

Abstract

A vertical shaft furnace, particularly a blast furnace, includes: an outer metal shell; a plurality of tuyeres configured to inject hot blast into the vertical shaft furnace; and means for injecting process gas into the furnace body region. The injector includes a nozzle body with a peripheral wall extending along a longitudinal axis from a front portion having at least one injection hole to a rear portion connected to a base member, wherein the nozzle body includes an internal gas passage for guiding process gas from an inlet port in the base member to one or more of the injection holes. The nozzle body is mounted through orifices in the metal shell such that the front portion having one or more injection holes is located inside the metal shell, while the rear portion is located outside the metal shell. The base member includes a peripheral mounting portion configured to hermetically connect the injector to a mounting unit surrounding the orifices in the metal shell. Furthermore, a process gas injector for a vertical shaft furnace is also provided.

Description

Technical Field

[0001] This invention relates generally to the field of metallurgy, and more specifically to the operation of a shaft furnace, i.e., a blast furnace, wherein a hot reducing gas is supplied to the furnace shaft, and particularly to the furnace body region. Background Technology

[0002] With the Paris Agreement and a near-global consensus on the necessity of taking emissions reduction actions, every industrial sector must research and develop solutions to improve energy efficiency and reduce carbon dioxide emissions.

[0003] Against this backdrop, players in the steel metallurgy sector have developed new methods to reduce the environmental footprint of blast furnace production lines. Indeed, despite alternative methods such as scrap melting or direct reduction in electric arc furnaces, the blast furnace (BF) remains the most widely used process in steel production today.

[0004] Among the methods developed to reduce CO2 emissions from blast furnaces, it has been proposed to introduce thermal reducing gas, typically syngas (which mainly consists of CO and H2), directly into the blast furnace shaft. This is also known as "shaft feed" and means introducing / supplying thermal reducing gas (syngas) through the furnace outer wall above the height of the hot blast (tuyere), i.e. above the furnace belly, and preferably in the gas-solid reduction zone of the ferrous oxide zone above the cohesive zone. Summary of the Invention

[0005] Purpose of the invention

[0006] The purpose of this invention is to improve the supply of thermal reducing gas into the blast furnace shaft. Invention Overview

[0008] Current gas injection practices stem from the observation that, despite numerous publications and patents referencing the concept of shaft feeding (i.e., introducing thermal process / reducing gases into the blast furnace shaft), industrial application in commercial blast furnaces has yet to be implemented. Some publications describe theoretical or experimental studies of gas injection in blast furnace shafts. Typically, CFD simulations or small-scale model experiments are used to investigate the effects of different parameters on gas permeation and distribution within the porous layered structure of coke and sinter / pellets present in the upper part of the blast furnace. Generally, these studies conclude that the penetration depth is rather limited, and the gas remains close to the blast furnace wall.

[0009] This invention proposes a vertical shaft furnace.

[0010] According to a vertical shaft furnace of the present invention, particularly a blast furnace, the vertical shaft furnace comprises:

[0011] A metal casing defining an outer wall of a furnace, preferably, the metal casing is provided with cooling elements and / or refractory material;

[0012] Multiple air vents are arranged around the outer wall at the height of the air vents to spray hot air into the vertical shaft furnace;

[0013] Apparatus for injecting process gas, particularly hot reducing gas, into the vertical shaft furnace at a jet height above the height of the tuyeres;

[0014] The device for injecting process gas includes at least one injector, the injector comprising:

[0015] A nozzle body having a peripheral wall extending along a longitudinal axis from a front portion having at least one injection hole to a rear portion opposite to the base member, wherein the nozzle body includes an internal gas passage for guiding gas from an inlet port in the base member to one or more of the injection holes;

[0016] The nozzle body is mounted through an orifice in the metal housing, such that a front region having one or more of the injection holes is located inside the metal housing, while a rear portion is located outside the metal housing; and

[0017] The base component includes a peripheral mounting portion configured to connect the injector to a mounting unit (mounting unit substrate positioned outside the housing) in a sealed (airtight) manner to the orifice in the metal housing.

[0018] This invention allows for increasing and adjusting the penetration depth of the injected process gas by providing an injector protruding within the furnace. The process gas is typically a thermal reducing gas, such as syngas, which primarily comprises CO and H2. The injector is preferably arranged to inject the thermal reducing gas into the furnace body region. In practice, such an injector is connected externally to a thermal reducing gas source (e.g., syngas (CO; H2)) via appropriate piping.

[0019] The injector has one or more injection holes (or nozzles) arranged laterally and / or at the tip of the injector body for discharging hot gas. Providing injection holes on a single injector offers significant flexibility regarding the direction of gas injection. Because the injector device is not limited to a single injection point, gas distribution can be increased.

[0020] Furthermore, such injectors can be oriented towards the center of the furnace or tangentially (towards the circumferential part of the inner shell). Tangential orientation helps to generate vortices in the blast furnace, which can increase gas distribution and mix with the gas rising from the tuyeres.

[0021] The number and angle of injectors, as well as the different combinations of the number, size, position, and angle of the injection holes in each injector, provide great flexibility to adapt the injector design to given process conditions or given blast furnaces (small / large blast furnaces).

[0022] Another advantage of this invention is that the injector can be easily retrofitted onto existing blast furnaces. By core drilling between the outer cooling channels of two adjacent cooling elements, the injector's dimensions are advantageously selected so that it can be placed between the two cooling elements (plate coolers – cast iron or copper, or others). Alternatively, the injector can be placed within a cooling wall with suitable cooling channels. This intervention can also be achieved during short-term blast furnace shutdowns using today's available rapid cooling wall replacement technologies.

[0023] In one embodiment, the opening in the metal housing is surrounded by a sealed mounting unit adapted to mate with the mounting portion of the base component.

[0024] In this implementation, the base member is configured to support the injector body, with the nozzle body secured to the base member at the rear portion of the nozzle body. The mounting portion surrounds the nozzle body and is sealed to the mounting unit. This allows the injector to be hermetically mounted to a metal housing. Proper hermetically tight mounting and injector design are particularly necessary because the process gases in the intended application contain CO and H2, which could spontaneously combust upon leakage to the outside or potentially form an explosive atmosphere when mixed with air.

[0025] The mounting unit may include a sleeve that surrounds the orifice and is securely fixed to the metal housing in a sealing manner. The sleeve is provided with a first annular flange that mates with a second annular flange on the mounting portion of the base component.

[0026] In one embodiment, the base member includes: a cup-shaped outer element having a bottom wall surrounded by sidewalls, the outer element including the second annular flange; and an inner element received within the outer element. The inner element has a first annular sealing surface that mates with the second annular sealing surface of the outer element.

[0027] In one embodiment, the internal element is annular and defines a central channel extending along the longitudinal axis, which forms an inlet port for process gas.

[0028] In one embodiment, the internal component has an outer peripheral surface including a first sealing surface; and the sidewall has an inner peripheral surface including a second sealing surface. The second sealing surface may be a truncated conical surface that tapers towards the bottom wall of the external component; and the first sealing surface is a mating truncated conical surface. Preferably, the first annular surface and the second annular surface have matching / identical cone angles.

[0029] The use of inner and outer conical sections provides a safety feature that allows for easy disassembly and airtight connection of the internal and external components, even if the probe is stuck inside the furnace due to mechanical or thermal deformation or due to accumulated parts or scaffolding. The external component, which is not in contact with the furnace atmosphere, can be removed, and the internal component, integrated with the nozzle body, can be removed separately to the outside. Alternatively, if the injector is completely deformed or has adhesive residue that prevents its removal, the injector can be forcefully pushed into the furnace. The internal component with the injector nozzle is then replaced with a spare part. Therefore, this design provides a safe and reliable way to disassemble, maintain, and replace the injector. For this purpose, the external dimensions of the nozzle body and internal components are designed to be smaller than the cross-section of the orifice in the metal housing, allowing the nozzle body and internal components to be pressed into the furnace.

[0030] The easily removable device also facilitates routine inspections of the injection area inside the furnace during blast furnace maintenance shutdowns. Removal of the injector allows for convenient inspection and possible cleaning / removal of scaffolding around the injection port.

[0031] In blast furnaces, injectors are typically arranged such that the front portion of the injector engages in an orifice in the metal shell, but also in an orifice in one or more cooling elements and / or in the refractory material covering the inner (or sometimes outer) surface of the metal shell. The nozzles of this invention are compatible with various cooling technologies, such as cooling plates / cooling walls or cooling boxes and spraying. Typically, the injector is positioned such that a certain length of the front portion of the nozzle body protrudes into the furnace, i.e., relative to the front side of the metal shell and / or one or more cooling elements and / or relative to the front of the cooling plate or the ceramic layer formed on the metal shell. The protrusion length can be adjusted depending on the application and configuration of the injection orifice. In some applications, such as for one or more axially protruding orifices, the tip of the injector can be arranged to protrude only slightly, or flush with the front side of the cooling element / ceramic layer. This may be desirable in applications where penetration depth is not a primary selection criterion but more emphasis is placed on injector life and reduced maintenance.

[0032] In some embodiments, a protruding cover is arranged above one or more injectors, and the protruding cover is configured to protect the front portion of the nozzle body protruding into the furnace from the impact of the descending load material. This protection of the injector nozzle body from abrasion by the descending load material (sinter / pellets and coke) can be achieved, for example, by an optionally water-cooled steel shell (smooth or corrugated); a ceramic or refractory lining; or a weld overlay made of abrasion-resistant material. Alternatively, the upper surface of the nozzle body can be shaped to facilitate the stagnation of the descending material. The injector can, for example, have a flat upper surface and upward peripheral ribs to retain the descending material.

[0033] Another possibility for protecting the protruding portion of the injector is to spray filler material above the injector to form a protective block. This can be accomplished via a feed channel arranged to extend from the area of ​​the base member and open in the front and upper regions of the peripheral wall, through which filler material can be sprayed after the injector is installed in the furnace shell. Thus, when the injector is installed in the furnace wall, filler material is introduced and accumulates above the injector as a protective substance.

[0034] Generally, injectors can be equipped with instruments that allow for thermal, mechanical, and / or process monitoring. For example, an injector may include one or more thermocouples to monitor the temperature of the gas flow. It may also include wear detection sensors.

[0035] Conveniently, the injector components have a generally axially symmetrical shape to facilitate manufacturing and installation. The nozzle body and base member can typically have a circular cross-section. In embodiments, elliptical or rectangular cross-sections are conceivable, particularly for the front portion of the nozzle body, but ideally the joint area between the nozzle body and the base member remains axially symmetrical.

[0036] The present invention also relates to a process gas injector for a shaft furnace as disclosed herein.

[0037] The injector includes a nozzle body having a peripheral wall extending along a longitudinal axis from a front portion having at least one injection orifice to an opposite rear portion connected to a base member. The nozzle body includes an internal gas passage for guiding process gas from an inlet port in the base member to one or more of the injection orifices. The nozzle body is configured for mounting via an orifice in a shaft furnace metal casing such that the front region having one or more injection orifices is located inside the metal casing, while the rear portion remains outside the metal casing. The base member includes a peripheral mounting portion configured for hermetically connecting the injector to a mounting unit surrounding the orifice in the metal casing.

[0038] This invention is an important complement to shaft feeding technology, for example, in applications such as those in currently developed syngas production methods or gas separation processes based on reforming of hydrocarbon-containing gases (coke oven gas, natural gas), thereby allowing CO and H2 to be concentrated in the gas stream for reuse after heating in the blast furnace. This invention will allow for the injection of large quantities of thermally reducing gas, thus significantly reducing coke consumption and CO2 emissions. Therefore, shaft feeding is an important technology for further improving the productivity of blast furnace processes, reducing operating costs, and decreasing coke consumption and CO2 emissions. Attached Figure Description

[0039] The invention will now be described by way of example with reference to the accompanying drawings, in which:

[0040] Figure 1 This is a schematic diagram of a blast furnace equipped with a vertical shaft for injecting thermal reducing gas.

[0041] Figure 2 : A schematic cross-sectional view of this injector installed in a blast furnace;

[0042] Figure 3 This is a schematic diagram illustrating a system used for injecting thermal reducing gas; and

[0043] Figure 4 a) A schematic diagram of the protective cover for the injector is shown in a side view, and b) A schematic diagram of the protective cover for the injector is shown in a front view. Detailed Implementation

[0044] Figure 1 A blast furnace 10 is schematically shown. The blast furnace 10 typically includes a hearth 12 and a metal shell 14 formed by a vertically extending shaft above the hearth 12. In this embodiment, the metal shell may be a steel shell. The upper region 12.1 of the hearth wall includes openings for tuyeres 16, which are used to introduce hot air into the furnace. In this upper region 12.1, the tuyeres 16 are distributed circumferentially around the furnace and supply hot air from peripheral / annular sleeves 18. The metal shell 14 is typically divided into three regions: the belly 14.1, the waist 14.2, and the shaft 14.3. The throat 20 of the blast furnace is closed by a top cone 22 with exhaust ports 24 and a top ring 26. Although not shown, a top charging device is arranged above the top cone 22 and is used to distribute the blast furnace feedstock into the furnace. The top charging device is preferably of the BELL LESS TOP® type, and the top charging device's distribution slot 28 is as follows... Figure 1 As shown.

[0045] The metal shell 14 forms the outer wall of the furnace. The inner surface of the metal shell 14 (i.e., facing the interior of the furnace) is typically covered with a cooling plate 30 (or cooling wall), such as... Figure 3 As better illustrated. This type of cooling plate typically has a plate-shaped body made of steel or copper (alloy) with internal coolant channels through which coolant (water) circulates. The front side of the cooling plate 30 (i.e., facing the furnace interior) is also typically covered with a protective layer of steel blade inserts or refractory material (not shown).

[0046] Figure 1 Reference numeral 32 in the attached figure indicates a vertical injection system configured to introduce thermal reducing gas into the vertical shaft of the blast furnace, specifically above the tuyeres. The thermal reducing gas is typically syngas containing CO and H₂. (See reference...) Figure 3The vertical jetting system 32 here includes multiple injectors 50 (described in detail below), which are connected to a first peripheral conduit 36 ​​(similar to sleeve 18) carrying syngas / process gas. In practice, the peripheral conduit is therefore connected to a process gas source (not shown). Each injector 50 is connected to the peripheral conduit 36 ​​via a separate connecting line 38. The injectors 50 are preferably water-cooled. Reference numeral 40 indicates a second peripheral conduit supplying fresh cooling water to the injectors, while the cooling water flowing out of the injectors is collected via a third peripheral conduit 42.

[0047] Now refer to Figure 2 A detailed description of an embodiment of the fuel injector is provided. The injector 50 includes a nozzle body 51 having a peripheral wall 52 extending from a front portion 54 along a longitudinal axis L to a rear portion 58 opposite to the base member 60. The peripheral wall 52 has, for example, two injection holes 56. The nozzle body 51 includes an internal gas passage 62 for guiding gas from an inlet port 64 in the base member 60 to the injection holes 56.

[0048] The nozzle body 51 is mounted through an orifice 66 in the metal housing 14 such that a front portion 54 having one or more injection holes is located inside the furnace, while a rear portion 58 is located outside the metal housing 14. The base member 60 is connected to the metal housing 14 in a sealing manner.

[0049] Because the metal housing 14 is internally covered by a cooling plate 30, the second orifice 66' is formed in the cooling plate (or adjacent cooling plate) in a manner that is axially continuous with the first orifice 66. The injector can therefore be suitably arranged with its front portion located inside the furnace. The nozzle body extends through the orifice in the metal housing 14 and the cooling plate 30 and protrudes from the cooling plate inside the furnace.

[0050] The second orifice 66' can be implemented in a single cooling plate or at the junction between two cooling plates, in a body section without internal coolant channels.

[0051] For ease of installation and sealing, a guide sleeve 67 (made of steel, ceramic, or a suitable metal alloy) may be arranged to extend into the two orifices 66, 66'. The outer diameter of the guide sleeve 67 corresponds to the diameter of the two orifices 66, 66', and the length of the guide sleeve 67 corresponds to the distance from the front side of the cooling plate to the outer side of the metal housing 14. The inner diameter of the guide sleeve 67 matches the outer diameter of the nozzle body 51.

[0052] An orifice 66 in the metal housing 14 is surrounded by a sealed mounting unit 68 adapted to mate with a peripheral mounting portion 70 of the base member 60. The mounting unit 68 includes a sleeve 68.1 (pipe segment) surrounding the orifice 66 and hermetically welded to the outer surface of the metal housing 14. The sleeve 68.1 extends generally along axis L away from the metal housing 14 and has a first annular flange 68.2 surrounding its inlet for mates with a second annular flange 70.1 of the peripheral mounting portion 70 of the base member. In this document, the terms "sealed" or "sealed" imply an airtight connection / assembly.

[0053] The base member 60 includes a cup-shaped outer element 72 and an inner element 74. The outer element 72 has a bottom wall 72.1 surrounded by sidewalls 72.2, and the inner element 74 is received within the outer element 72. The outer element 72 is oriented such that the recess of the outer element that receives the inner element 74 faces the nozzle body 51 of the injector. A peripheral mounting portion 70 is arranged in an axially continuous portion of the sidewall 72.2 facing the mounting unit 68. The peripheral mounting portion 70 includes a sleeve portion 70.2, which is welded to the outer element at one end and has a second annular flange 70.1 at the other end.

[0054] The internal element 74 is annular and defines a central channel 74.1 extending along a longitudinal axis L, the central channel forming the inlet port 64 for the process gas. The annular internal element 74 has a generally conical cross-section, an outer peripheral surface 74.2 opposite to the inner surface 74.1, and radially extending front and rear surfaces 74.3 and 74.4 of the nozzle body 51 of the directional injector and the bottom wall 72.1 of the outer element, respectively.

[0055] The outer peripheral surface 74.2 of the internal component includes a first annular sealing surface 74.5, which mates with a facing second annular sealing surface 72.3 on the inner side of the sidewall 72.2. In this embodiment, the first annular sealing surface 74.5 and the second annular sealing surface 72.3 are designed as mating truncated tapered surfaces to provide a metal-to-metal hermetic seal. Additional sealing can be achieved using O-rings or other metal seals. The second annular sealing surface 72.3 tapers towards the bottom wall 72.1, increasing the contact pressure at the sealing surface as it pushes the internal component 74 into the interior of the external component 72. Preferably, the taper angle of the first annular sealing surface 74.5 is the same as that of the second annular sealing surface 72.3.

[0056] The internal component 74 is secured to the external component 72 by a screw 76, which is engaged through the bottom wall 72.1 of the external component 72.

[0057] The nozzle body 51 also includes an inner tube 80 that extends axially from the base member 60 toward the front region in a manner continuous with respect to the central channel 74.1. The inner tube 80 is configured to guide process gas from the inlet port 64 to the injection orifice.

[0058] like Figure 2 As shown, the inlet port 64 includes a connecting conduit 65, which is fixed to the rear surface 74.4 of the internal component and surrounds the channel 74.1. The connecting conduit 65 extends through the bottom wall 72.1 in the opening 72.4 and includes a connecting portion, such as an annular flange 65.1, for connection to a corresponding flange 38.1 of a connecting conduit 38 communicating with a peripheral conduit 36 ​​supplying heat-reducing gas. Although not shown, the connecting conduit 65 and the connecting conduit 38 may be provided with a refractory lining.

[0059] The components of the nozzle body 51 and the base member 60 can typically be made of steel, steel alloy, or metal alloy. In this embodiment, the peripheral wall 52 and the inner tube 80 can be made of copper or copper alloy.

[0060] As can be seen, both the peripheral wall 52 and the inner tube 80 are constructed as tubular members that are closed at the front (except for the injection hole) and open at the rear, with the peripheral wall 52 and the inner tube 80 supported at the rear by the internal element 74. The term "supported" here means that the rear ends of the peripheral wall 52 and the inner tube 80 are fixed to the internal element 74, for example, by welding. Since the inlet of the inner tube 80 surrounds the central channel 74.1, and the peripheral wall 52 surrounds the inner tube 80, a closed annular gap 82 is formed between the two tubes.

[0061] With this double-wall configuration, the injection hole 56 is formed by a small tube segment 57 extending from the inner tube 80 to the peripheral wall, such as... Figure 2 As shown.

[0062] In this variant, the injection port 56 is tilted forward, thus facing the center of the shaft. Typically, the injection port can be configured to inject process gas axially (opening in the tip of the injector body) or laterally, as shown, forward or downward (perpendicular to axis L), or even tangentially (i.e., along the circumferential portion of the inner casing) to create a vortex effect.

[0063] Reference numeral 77 indicates a centering ring fixed to the front surface 74.3 of the inner ring. The dimensions (diameter / thickness) of this centering ring substantially correspond to the dimensions of the guide sleeve 67. Therefore, the thickness of the centering ring 77 corresponds to the annular space between the outer wall and the sleeve 70.2.

[0064] The fuel injector 50 is exposed to a large amount of heat within the furnace. Therefore, an outer heat protection layer 84, made of, for example, ceramic material, steel alloy, or hardface, is formed on the outer surface of the peripheral wall 52. An inner heat protection layer 86, preferably based on ceramic or refractory material, protects the inner surface of the inner tube 80. In embodiments, the inner heat protection layer 86 may be an insulating layer. An intermediate layer made of metal or insulating material may be disposed between the inner tube 80 and the inner heat protection layer 86. Preferably, the copper-based components (peripheral wall 52 and inner tube 80) and the steel layers (intermediate layer and outer heat protection layer 84) are metallurgically bonded together through a diffusion layer.

[0065] Preferably, water can flow through the annular gap 82 formed in the nozzle body 51. It is foreseeable that the annular gap 82 can avoid stagnation zones and ensure a sufficiently high water velocity through the guiding element, thereby allowing effective protection of the injector from the heat of the blast furnace on one hand and the effects of the hot syngas on the other. Therefore, a coolant inlet channel is formed in the base member 60, comprising an inlet guide channel 88 (larger than the first cooling pipe 96) in the sidewall 72.2 of the outer element 72 and a curved channel 90, the curved channel 90 having a threaded inlet portion and an opening from the first annular sealing surface 74.5 to the front surface 74.3 of the inner element 74 communicating with the annular gap 82.

[0066] The coolant outlet passage includes an outlet guide passage 92 and a curved passage 94 having a threaded inlet portion. The outlet guide passage 92 is spaced apart from / opposite to the inlet portion 88 in the sidewall 72.2 of the outer element 72. The curved passage 94 extends from the first annular sealing surface 74.5 to an opening in the front surface 74.3 of the inner element 74 that communicates with the annular gap 82.

[0067] Additional sealing elements may be arranged on the outer surface of the inlet and outlet passages having sidewalls 72.2.

[0068] A first cooling pipe 96 is fitted into an inlet guide channel 88 and further extends into a bend channel 90, where the first cooling pipe 96 is screwed into the inlet portion in a sealing manner. At the opposite end, the first cooling pipe 96 includes a connector (not shown) for direct or indirect connection to the peripheral pipe 40. A second cooling pipe 98 is fitted into an inlet portion 92 and further extends into a bend channel 94, where the second cooling pipe 98 is screwed into the inlet portion in a sealing manner. At the opposite end, the second cooling pipe 98 includes a connector (not shown) for direct or indirect connection to the peripheral pipe 42. In an embodiment, the first cooling pipe 96 and the second cooling pipe 98 may be water pipes or coolant pipes. The inlet guide channel 88 and the outlet guide channel 92 have a cross-section slightly larger than the outer diameter of the first cooling pipe 96 and the second cooling pipe 98.

[0069] Reference numeral 68.3 indicates a filling nozzle through which grouting material, insulating material or similar material can be sprayed into the gap 79 between the nozzle body 51 and the sleeve 68.1 (on the outside of the furnace), thereby reducing the risk of leakage and / or filling with dust, etc.

[0070] In one embodiment, a protruding cover may be arranged above one or more injectors, and this protruding cover is configured to protect the front portion of the nozzle body protruding into the furnace from the impact of descending load material. This protection of the injector nozzle body from abrasion by the descending load material (sinter / pelletized ore and coke) can be achieved, for example, by a smooth or corrugated steel casing. The principle of the protruding cover 100 is as follows... Figure 4 As shown, a cap extending along the longitudinal direction L of the injector is formed. This protruding cover 100 covers the protruding length of the injector (shown by dashed lines). It can be seen that the protruding cover 100 is a curved steel profile, more specifically having an inverted, rounded V-shape. The apex 100.1 of the V-shape is above the injector 50, and two branches 100.2 extend on both sides of the injector 50, optionally even extending below the injector. The protruding cover 100 can be cooled directly or indirectly by liquid. Coolant channels can be arranged, for example, on the lower side of the housing.

[0071] It should also be noted that the connecting pipe 38 may include an elbow 38.1, the rear of which is provided with a maintenance and inspection port 38.2, the longitudinal central axis of which corresponds to the longitudinal axis L of the injector. A cover, observation glass, and / or camera are detachably attached to the inspection port 38.2. The glass can be observed simultaneously using both a camera and vision, for example, by using a properly positioned beam splitter. Since the interior of the blast furnace is dark at the shaft height, opposite to the tuyeres height, the camera is preferably a thermal and / or infrared camera and / or one that can provide additional light source.

Claims

1. A vertical shaft furnace, the vertical shaft furnace comprising: A metal casing (14) defines an outer wall of the furnace; Multiple air vents (16) are arranged around the metal casing (14) at the height of the air vents to inject hot air into the vertical shaft furnace; A device for injecting process gas into the vertical shaft furnace at a jet height higher than the height of the tuyeres; The vertical shaft furnace is characterized in that the apparatus for injecting process gas into the vertical shaft furnace includes at least one injector (50), the injector (50) comprising: A nozzle body (51) having a peripheral wall (52) extending along a longitudinal axis from a front portion (54) having at least one injection hole (56) to a rear portion (58) opposite to a base member (60) configured to support the nozzle body (51), wherein the nozzle body (51) includes an internal gas passage (62) for guiding process gas from an inlet port (64) in the base member (60) to one or more of the injection holes (56). The nozzle body (51) is mounted through an orifice in the metal housing (14) such that the front portion (54) having one or more of the spray holes (56) is located inside the metal housing (14), while the rear portion (58) is located outside the metal housing (14). And wherein the base member (60) includes a peripheral mounting portion (70) surrounding a portion of the rear portion (58) of the nozzle body (51), and the peripheral mounting portion (70) is configured to connect the injector (50) to a mounting unit (68) surrounding the orifice in the metal housing (14) in an airtight manner.

2. The vertical shaft furnace according to claim 1, wherein, The vertical shaft furnace is a blast furnace, and / or the process gas is a thermal reducing gas.

3. The vertical shaft furnace according to claim 1 or 2, wherein, The metal casing (14) is provided with cooling elements and / or refractory materials.

4. The vertical shaft furnace according to claim 1 or 2, wherein, The mounting unit (68) includes a sleeve (68.1) that surrounds the orifice and is fixed to the metal housing (14) in a sealed manner; the sleeve (68.1) is provided with a first annular flange (68.2) that engages with a second annular flange (70.1) on the peripheral mounting portion (70) of the base member (60).

5. The vertical shaft furnace according to claim 4, wherein, The base component (60) includes: An external element (72), the external element (72) being cup-shaped, the external element (72) having a bottom wall (72.1) surrounded by sidewalls (72.2), the external element (72) including a second annular flange (70.1); and An internal element (74) is received within the external element (72); The internal element (74) has a first annular sealing surface (74.5) that mates with the second annular sealing surface (72.3) of the external element (72).

6. The vertical shaft furnace according to claim 5, wherein, The internal element (74) is annular and defines a central channel (74.1) extending along the longitudinal axis, the central channel (74.1) forming the inlet port (64) of the process gas.

7. The vertical shaft furnace according to claim 5, wherein, The internal element (74) has an outer peripheral surface including the first annular sealing surface (74.5); and the sidewall (72.2) has an inner peripheral surface including the second annular sealing surface (72.3).

8. The vertical shaft furnace according to claim 7, wherein, The second annular sealing surface (72.3) is a truncated conical surface that tapers toward the bottom wall (72.1) of the external element (72); and the first annular sealing surface (74.5) is a mating truncated conical surface.

9. The vertical shaft furnace according to claim 6, wherein, The nozzle body (51) includes an inner tube (80) that extends axially from the base member (60) toward the tip in a manner that is axially continuous with the central channel (74.1), and the inner tube (80) is configured to guide process gas from the inlet port (64) to the injection hole (56).

10. The vertical shaft furnace according to claim 9, wherein, A closed annular gap (82) is formed between the inner tube (80) and the peripheral wall (52); and The base component (60) includes a coolant inlet channel and a coolant outlet channel, the coolant inlet channel and the coolant outlet channel being arranged to supply coolant fluid to the annular gap (82) and correspondingly extract coolant fluid from the annular gap (82).

11. The vertical shaft furnace according to claim 10, wherein, The coolant inlet passage includes an inlet guide passage (88) in the sidewall (72.2) of the outer element (72) and a curved passage that leads from the first annular sealing surface (74.5) to the front side of the inner element (74) and communicates with the annular gap (82); and The coolant outlet channel includes an outlet guide channel (92) in the sidewall (72.2) of the outer element (72) and a curved channel that leads from the first annular sealing surface (74.5) to the front side of the inner element (74) and communicates with the annular gap (82).

12. The vertical shaft furnace according to claim 11, wherein, A first cooling pipe (96) is sealed in the coolant inlet channel, and a second cooling pipe (98) is sealed in the coolant outlet channel. Each of the first cooling pipe (96) and the second cooling pipe (98) has a connector for connecting to a corresponding coolant supply pipe and a collection pipe.

13. The vertical shaft furnace according to claim 1 or 2, wherein, The metal housing (14) is provided with cooling elements, and the nozzle body (51) is also inserted through an orifice in one or more of the cooling elements, whereby the front portion (54) protrudes from the hot side of one or more of the cooling elements at a predetermined distance from the hot side of one or more of the cooling elements.

14. The vertical shaft furnace according to claim 13, wherein, A ceramic layer is formed on the hot side of the cooling element, and the nozzle body (51) is also inserted through an orifice in the ceramic layer, thereby the front portion (54) protrudes from the ceramic layer at a predetermined distance from the ceramic layer.

15. The vertical shaft furnace according to claim 1 or 2, wherein, A ceramic layer is formed on the metal housing (14), and the nozzle body (51) is also inserted through an orifice in the ceramic layer, thereby the front portion (54) protrudes from the ceramic layer at a predetermined distance from the ceramic layer.

16. The vertical shaft furnace according to claim 1 or 2, wherein, A protruding cover (100) is arranged above one or more of the injectors, and the protruding cover (100) is configured to protect the front portion (54) of the nozzle body (51) protruding into the shaft furnace from the impact of falling furnace charge.

17. The vertical shaft furnace according to claim 1 or 2, wherein, The injection orifice (56) is configured to allow the injection of process gas along and / or transverse to the longitudinal axis; and / or At least some of the injection holes (56) are arranged laterally in the front portion (54) to inject gas downstream of the shaft furnace or to inject gas tangentially.

18. The vertical shaft furnace according to claim 1 or 2, wherein, The injector (50) is arranged to pass through the metal housing (14) such that the longitudinal axis of the injector (50) points toward the center of the shaft furnace or is oriented tangentially.

19. The vertical shaft furnace according to claim 6, wherein, The injector (50) includes a connecting pipe (65) which is connected at one end to the rear face of the inner element (74) and surrounds the central channel (74.1), the connecting pipe (65) extends through an opening (72.4) in the bottom wall (72.1) of the outer element (72), and includes a connector at the other end of the connecting pipe (65).

20. The vertical shaft furnace according to claim 19, wherein, The apparatus for injecting process gas into the shaft furnace includes a peripheral conduit (36) surrounding the metal casing (14), and each injector (50) is connected to the peripheral conduit (36) via a separate connecting line (38) to a connector of the connecting conduit (65) of the injector (50).

21. The vertical shaft furnace according to any one of claims 9 to 12, wherein, The peripheral wall (52) is covered with an outer heat protection layer (84) and / or the inner tube (80) is provided with an inner heat protection layer (86).

22. The vertical shaft furnace according to any one of claims 9 to 12, wherein, The peripheral wall (52) is covered with a weld overlay made of wear-resistant material.

23. The vertical shaft furnace according to claim 1 or 2, wherein, The injector (50) includes one or more thermocouples and / or wear detectors.

24. The vertical shaft furnace according to claim 1 or 2, wherein, The upper surface of the nozzle body (51) is shaped to facilitate the stagnation of the descending material.

25. The vertical shaft furnace according to claim 24, wherein, The upper surface of the nozzle body (51) is shaped to facilitate the stagnation of descending material through a flat upper surface with upward peripheral ribs.

26. The vertical shaft furnace according to claim 1 or 2, wherein, The injector (50) includes a feed channel for filling material, which is open in the front and upper regions of the peripheral wall (52).

27. The vertical shaft furnace according to claim 5, wherein, The external dimensions of the nozzle body (51) and the internal element (74) are designed to be smaller than the cross-section of the orifice in the metal housing (14), so that the nozzle body (51) and the internal element (74) can be forced into the shaft furnace.

28. The vertical shaft furnace according to claim 1 or 2, wherein, The mounting unit (68) or the peripheral mounting portion (70) includes a filling nozzle (68.3) for spraying grouting material and insulating material into an annular space surrounding the peripheral wall (52).

29. A process gas injector for a vertical shaft furnace, the process gas injector comprising a nozzle body (51) having a peripheral wall (52) extending along a longitudinal axis from a front portion (54) having at least one injection hole (56) to an opposite rear portion (58) connected to a base member (60), the base member (60) being configured to support the nozzle body (51), wherein, The nozzle body (51) includes an internal gas passage (62) for guiding process gas from an inlet port (64) in the base member (60) to one or more of the injection holes (56). The nozzle body (51) is configured to pass through an orifice in the metal casing (14) of the vertical shaft furnace, such that a front portion (54) having one or more of the injection holes (56) is located inside the metal casing (14), while a rear portion (58) remains outside the metal casing (14); and The base member (60) includes a peripheral mounting portion (70) surrounding a portion of the rear portion (58) of the nozzle body (51), and the peripheral mounting portion (70) is configured to connect the process gas injector to a mounting unit (68) surrounding an orifice in the metal housing (14) in an airtight manner.

Images