Classifications

• • C—CHEMISTRY; METALLURGY
  • C21—METALLURGY OF IRON
  • C21B—MANUFACTURE OF IRON OR STEEL
  • C21B7/00—Blast furnaces
  • C21B7/16—Tuyéres

Definitions

• This application discloses a blast furnace, a blast furnace tuyere, and a method for supplying reducing gas to a blast furnace.
• Patent Documents 1 and 2 disclose a method in which a lance for injecting reducing gas is disposed in the hot blast flow path or wall surface of a hot blast tuyere, and reducing gas is injected through the lance.
• Patent Document 3 discloses a method in which a fuel injection lance is inserted into the wall surface of a hot blast tuyere, and pulverized coal as fuel is injected into the blast furnace through the fuel injection lance.
• a blast furnace having hot blast tuyere The hot air tuyere
• the tuyere body has a hot air flow path
• the first reducing gas injection port penetrates the wall of the tuyere body
• the second reducing gas injection port penetrates the wall of the tuyere body at a different location than the first reducing gas injection port; Blast furnace.
• a blast furnace of aspect 1 an outlet of the first reducing gas blowing port and an outlet of the second reducing gas blowing port each face the hot air flow path; Blast furnace.
• a height position P1 of the center of the outlet of the first reducing gas injection port is higher than a height position P2 of the center of the opening of the tuyere body
• the height position P3 of the center of the outlet of the second reducing gas injection port is lower than the height position P2 of the center of the opening of the tuyere body.
• a method for supplying reducing gas to a blast furnace comprising: Hot air is supplied into the inside of the blast furnace through a hot air tuyere of the blast furnace, supplying a reducing gas into the blast furnace through a first reducing gas injection port penetrating a wall of a tuyere body of the hot air tuyere and a second reducing gas injection port penetrating a wall of the tuyere body at a position different from the first reducing gas injection port;
• a method for supplying reducing gas to a blast furnace comprising: ⁇ Aspect 6> A method for supplying a reducing gas to a blast furnace according to aspect 5, A reducing gas is supplied to the hot air flow path of the tuyere body from each of the outlet of the first reducing gas blowing port and the outlet of the second reducing gas blowing port.
• a method for supplying reducing gas to a blast furnace A method for supplying reducing gas to a blast furnace.
• a height position P1 of the center of the outlet of the first reducing gas injection port is higher than a height position P2 of the center of the opening of the tuyere body,
• the height position P3 of the center of the outlet of the second reducing gas injection port is lower than the height position P2 of the center of the opening of the tuyere body.
• a method for supplying reducing gas to a blast furnace A method for supplying reducing gas to a blast furnace.
• the reducing gas comprises hydrogen gas.
• a tuyere for a blast furnace The tuyere body, a first reducing gas injection port; a second reducing gas injection port; and The tuyere body has a hot air flow path, the first reducing gas injection port penetrates the wall of the tuyere body; the second reducing gas injection port penetrates the wall of the tuyere body at a different location than the first reducing gas injection port; Tuyere for blast furnace.
• the technology disclosed herein makes it possible to suppress unevenness in the concentration of reducing gas in the radial direction inside a blast furnace when reducing gas is supplied into the furnace.
• 1 is a schematic diagram illustrating an example of the configuration of a blast furnace, with some components provided in the blast furnace omitted.
• 1 is a schematic diagram showing an example of the configuration of a tuyere body, a first reducing gas injection port, and a second reducing gas injection port in a hot blast tuyere, in which the upper side of the drawing corresponds to the furnace top side and the lower side of the drawing corresponds to the furnace bottom side.
• FIG. 1 is a schematic diagram showing an example of the configuration of a tuyere body, a first reducing gas injection port, and a second reducing gas injection port in a hot blast tuyere, in which the upper side of the drawing corresponds to the furnace top side and the lower side of the drawing corresponds to the furnace bottom side.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the first reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the first reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the first reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the first reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the first reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the second reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the second reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the second reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the second reducing gas injection port.
• 10 is a schematic diagram showing an example of the positional relationship between the opening of the tuyere body in the hot blast tuyere and the outlet of the second reducing gas injection port. Simulation conditions are shown.
• Simulation conditions are shown. Simulation conditions are shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. Simulation conditions are shown. Simulation conditions are shown. Simulation conditions are shown. Simulation conditions are shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown. The hydrogen concentration distribution based on the simulation results is shown.
• blast furnace and method for supplying reducing gas to a blast furnace disclosed herein are described.
• the blast furnace and method for supplying reducing gas to a blast furnace disclosed herein are not limited to the following embodiment.
• a blast furnace 100 has a hot blast tuyere 10.
• the hot blast tuyere 10 has a tuyere body 11, a first reducing gas injection port 12, and a second reducing gas injection port 13.
• the tuyere body 11 has a hot blast flow path 11a.
• the first reducing gas injection port 12 penetrates the wall of the tuyere body 11.
• the second reducing gas injection port 13 penetrates the wall of the tuyere body 11 at a position different from that of the first reducing gas injection port 12.
• the hot blast tuyere 10 is provided, for example, below the shaft lower end 101ax of the blast furnace 100 and above the tap hole 102.
• the "shaft lower end” refers to the boundary between the shaft 101a and the belly 101b.
• the “shaft” refers to the portion above the belly 101b, where the furnace diameter typically increases from top to bottom.
• the “belly” refers to the portion below the shaft and above the bosch 101c, where the furnace diameter typically is greatest.
• the furnace diameter (diameter) of the belly 101b may be, for example, 5 m or more and 20 m or less, or 10 m or more and 18 m or less.
• the "tap hole” refers to a molten iron tap port provided at the bottom of the blast furnace 100.
• the "hot blast tuyere” refers to a nozzle for supplying hot air to the blast furnace.
• the blast furnace 100 may have a hot air tuyere 10 below the belly lower end 101bx and above the tap hole 102, or may have a hot air tuyere 10 below the morning glory lower end 101cx and above the tap hole 102.
• the number of hot air tuyere 10 provided in the blast furnace 100 is not particularly limited and can be determined according to the internal volume of the blast furnace.
• a plurality of hot air tuyere 10 may be arranged in the circumferential direction of the blast furnace 100.
• a plurality of hot air tuyere 10 may be arranged in the circumferential direction when viewed from above.
• the height position P2 of the center of each of the plurality of hot air tuyere 10 is the same.
• the tuyere body 11 is a hollow member having a hot air flow path 11a.
• the upstream side of the hot air flow path 11a of the tuyere body 11 is connected to a blowpipe (not shown), and the downstream side of the hot air flow path 11a faces the interior of the blast furnace 100.
• the tuyere body 11 has an opening 11ax (hot air outlet) as an outlet of the hot air flow path 11a at the tip facing the interior of the blast furnace 100.
• the tuyere body 11 can be connected to a hot air stove outside the blast furnace 100 via a hot air pipe, a blowpipe, or the like.
• the blast furnace 100 can be configured so that hot air is supplied from the hot air stove to the interior of the blast furnace 100 via the hot air pipe, the blowpipe, and the tuyere body 11.
• the opening diameter of the tuyere body 11 (the circle-equivalent diameter of the opening 11ax facing the inside of the blast furnace 100, the nozzle diameter) may be, for example, 20 mm or more and 400 mm or less, or 40 mm or more and 300 mm or less.
• the wall of the tuyere body 11 has, for example, an inner surface 11x facing the hot air flow path 11a, and an outer surface 11y and end surface 11z facing the inside of the blast furnace 100.
• a first reducing gas injection port 12 and a second reducing gas injection port 13, which will be described later, are provided to penetrate the wall.
• the tuyere body 11 may have a cooling water flow path inside the wall. This allows the tuyere body 11 and its surroundings to be cooled during operation of the blast furnace 100, thereby preventing thermal damage and the like.
• the tuyere body 11 is made of a known material, for example, copper.
• the first reducing gas injection port 12 can be connected to a reducing gas supply source 20 outside the blast furnace 100 via a reducing gas supply passage 21 or the like.
• the blast furnace 100 can be configured so that reducing gas is supplied from the reducing gas supply source 20 to the inside of the blast furnace 100 via the reducing gas supply passage 21 and the first reducing gas injection port 12.
• the configurations of the reducing gas supply source 20 and the reducing gas supply passage 21 are no particular limitations on the configurations of the reducing gas supply source 20 and the reducing gas supply passage 21.
• the first reducing gas injection port 12 is provided so as to penetrate the wall of the tuyere body 11.
• the first reducing gas injection port 12 has a flow path 12a in the wall surface of the tuyere body 11, and has an outlet 12ax downstream of the flow path 12a.
• the length, longitudinal shape, opening shape, etc. of the flow path 12a of the first reducing gas injection port 12 can be determined appropriately taking into account the wall thickness of the tuyere body 11 and the water-cooling structure within the wall.
• the outlet 12ax of the first reducing gas injection port 12 may face the hot air flow path 11a. That is, the first reducing gas injection port 12 may supply reducing gas so that it joins the hot air flow path 11a.
• the outlet 12ax of the first reducing gas injection port 12 may be provided on the end face 11z of the tuyere body 11. That is, the first reducing gas injection port 12 may supply reducing gas into the interior of the blast furnace 100 independently of the hot air flow path 11a.
• the reducing gas concentration distribution in the radial direction of the blast furnace 100 can be made more uniform.
• the distance from the center (centroid) of the downstream opening 11ax of the hot air flow path 11a to the center (centroid) of the outlet 12ax of the first reducing gas injection port 12 is not particularly limited. This distance may be, for example, 50 mm to 300 mm, or 70 mm to 150 mm.
• the diameter (diameter of a circle with an area equivalent) of the outlet 12ax of the first reducing gas injection port 12 may be, for example, 10 mm or more and 50 mm or less, or 20 mm or more and 30 mm or less.
• the diameter of the outlet 12ax of the first reducing gas injection port 12 may be 10% or more and 50% or less, or 15% or more and 30% or less, of the diameter of the opening 11ax of the tuyere body 11. When the outlet 12ax has such a diameter, it is easier to control the flow rate of the reducing gas.
• the second reducing gas injection port 13 can be connected to a reducing gas supply source 20 outside the blast furnace 100 via a reducing gas supply passage 21 or the like.
• the blast furnace 100 can be configured so that reducing gas is supplied from the reducing gas supply source 20 to the inside of the blast furnace 100 via the reducing gas supply passage 21 and the second reducing gas injection port 13.
• the configuration of the reducing gas supply source 20 or the reducing gas supply passage 21 There are no particular limitations on the configuration of the reducing gas supply source 20 or the reducing gas supply passage 21.
• the reducing gas supply source 20 and the reducing gas passage 21 connected to the second reducing gas injection port 13 may have the same configuration as the reducing gas supply source 20 and the reducing gas passage 21 connected to the first reducing gas injection port 12 described above, or may have a different configuration.
• the reducing gas supply source connected to the first reducing gas injection port 12 and the reducing gas supply source connected to the second reducing gas injection port 13 may be the same or different. That is, reducing gas may be supplied from one reducing gas supply source to each of the first reducing gas injection port 12 and the second reducing gas injection port 13 via a branch flow path, or reducing gas may be supplied from one reducing gas supply source to the first reducing gas injection port 12 and from a separate reducing gas supply source to the second reducing gas injection port 13.
• the second reducing gas injection port 13 is provided at a different position from the first reducing gas injection port 12, penetrating the wall of the tuyere body 11.
• the second reducing gas injection port 13 has a flow path 13a in the wall surface of the tuyere body 11, and has an outlet 13ax downstream of the flow path 13a.
• the length, longitudinal shape, opening shape, etc. of the flow path 13a of the second reducing gas injection port 13 can be determined appropriately taking into account the wall thickness of the tuyere body 11 and the water-cooling structure within the wall.
• the outlet 13ax of the second reducing gas injection port 13 may face the hot air flow path 11a. That is, the second reducing gas injection port 13 may supply reducing gas so that it joins the hot air flow path 11a.
• the outlet 13ax of the second reducing gas injection port 13 may be provided on the end face 11z of the tuyere body 11. That is, the second reducing gas injection port 13 may supply reducing gas into the interior of the blast furnace 100 independently of the hot air flow path 11a.
• the concentration distribution of the reducing gas in the radial direction of the blast furnace 100 can be made more uniform.
• the distance from the center (centroid) of the downstream opening 11ax of the hot air flow path 11a to the center (centroid) of the outlet 13ax of the second reducing gas injection port 13 is not particularly limited. This distance may be, for example, 50 mm or more and 300 mm or less, or 75 mm or more and 150 mm or less.
• the diameter (diameter of a circle with an area equivalent) of the outlet 13ax of the second reducing gas injection port 13 may be, for example, 10 mm or more and 50 mm or less, or 20 mm or more and 30 mm or less.
• the diameter of the outlet 13ax of the second reducing gas injection port 13 may be 10% or more and 50% or less, or 15% or more and 30% or less, of the diameter of the opening 11ax of the tuyere body 11. When the outlet 13ax has such a diameter, it is easier to control the flow rate of the reducing gas.
• the hot air tuyere 10 may have other reducing gas injection ports in addition to the first reducing gas injection port 12 and the second reducing gas injection port 13.
• the form of the other reducing gas injection ports is not particularly limited.
• the number of other reducing gas injection ports provided in the hot air tuyere 10 may be one or more.
• the height positions of the reducing gas injection ports provided in the hot air tuyere 10 are not particularly limited. The height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 and the height position P3 of the center of the outlet 13ax of the second reducing gas injection port 13 will be described later.
• the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be higher than the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 12ax of the first reducing gas injection port 12 may be located directly above the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 12ax of the first reducing gas injection port 12 in the circumferential direction of the blast furnace 100 may be the same as the position of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 12ax of the first reducing gas injection port 12 may be located diagonally above the center of the opening 11ax of the tuyere body 11. That is, in the circumferential direction of the blast furnace 100, the position of the center of the outlet 12ax of the first reducing gas injection port 12 may be different from the position of the center of the opening 11ax of the tuyere body 11. For example, as shown in FIG. 3B , when the opening 11ax of the tuyere body 11 is viewed from the front, a line L1 passing through the center of the opening 11ax and the center of the outlet 12ax may be inclined by an angle ⁇ 1 with respect to a vertical line L2 passing through the center of the opening 11ax.
• the angle ⁇ 1 may be, for example, between 0° and 45°. Note that while FIG. 3B illustrates an example in which the outlet 12ax is located on the left half side of the tuyere body 11, the outlet 12ax may also be located on the right half side of the tuyere body 11.
• the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be lower than the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 12ax of the first reducing gas injection port 12 may be provided directly below the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 12ax of the first reducing gas injection port 12 in the circumferential direction of the blast furnace 100 may be the same as the position of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 12ax of the first reducing gas injection port 12 may be provided obliquely below the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 12ax of the first reducing gas injection port 12 in the circumferential direction of the blast furnace 100 may be different from the position of the center of the opening 11ax of the tuyere body 11. For example, as shown in Fig. 3D , when the opening 11ax of the tuyere body 11 is viewed from the front, a line L1 passing through the center of the opening 11ax and the center of the outlet 12ax may be inclined at an angle ⁇ 2 with respect to a vertical line L2 passing through the center of the opening 11ax.
• the angle ⁇ 2 may be, for example, between 0° and 45°.
• Fig. 3D illustrates an example in which the outlet 12ax is located on the left half side of the tuyere body 11, but the outlet 12ax may also be located on the right half side of the tuyere body 11.
• the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be the same as the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 12ax of the first reducing gas injection port 12 may be provided directly beside the center of the opening 11ax of the tuyere body 11. Note that, although Fig. 3E illustrates an example in which the outlet 12ax is located on the left half side of the tuyere body 11, the outlet 12ax may also be located on the right half side of the tuyere body 11.
• the height position P3 of the center of the outlet 13ax of the second reducing gas injection port 13 may be higher than the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 13ax of the second reducing gas injection port 13 may be located directly above the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 13ax of the second reducing gas injection port 13 in the circumferential direction of the blast furnace 100 may be the same as the position of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 13ax of the second reducing gas injection port 13 may be located diagonally above the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 13ax of the second reducing gas injection port 13 in the circumferential direction of the blast furnace 100 may be different from the position of the center of the opening 11ax of the tuyere body 11. For example, as shown in Fig. 4B , when the opening 11ax of the tuyere body 11 is viewed from the front, a line L3 passing through the center of the opening 11ax and the center of the outlet 13ax may be inclined at an angle ⁇ 3 with respect to a vertical line L2 passing through the center of the opening 11ax.
• the angle ⁇ 3 may be, for example, between 0° and 45°.
• Fig. 4B illustrates an example in which the outlet 13ax is located on the left half side of the tuyere body 11, but the outlet 13ax may also be located on the right half side of the tuyere body 11.
• the height position P1 of the center of the outlet 13ax of the second reducing gas injection port 13 may be lower than the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 13ax of the second reducing gas injection port 13 may be provided directly below the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 13ax of the second reducing gas injection port 13 in the circumferential direction of the blast furnace 100 may be the same as the position of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 13ax of the second reducing gas injection port 13 may be provided obliquely below the center of the opening 11ax of the tuyere body 11. That is, the position of the center of the outlet 13ax of the second reducing gas injection port 13 in the circumferential direction of the blast furnace 100 may be different from the position of the center of the opening 11ax of the tuyere body 11. For example, as shown in Fig. 4D , when the opening 11ax of the tuyere body 11 is viewed from the front, a line L3 passing through the center of the opening 11ax and the center of the outlet 13ax may be inclined at an angle ⁇ 4 with respect to a vertical line L2 passing through the center of the opening 11ax.
• the angle ⁇ 4 may be, for example, between 0° and 45°.
• Fig. 4D illustrates an example in which the outlet 13ax is located on the left half side of the tuyere body 11, but the outlet 13ax may also be located on the right half side of the tuyere body 11.
• the height position P1 of the center of the outlet 13ax of the second reducing gas injection port 13 may be the same as the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the center of the outlet 13ax of the second reducing gas injection port 13 may be provided directly beside the center of the opening 11ax of the tuyere body 11. Note that, although Fig. 4E illustrates an example in which the outlet 13ax is located on the left half side of the tuyere body 11, the outlet 13ax may also be located on the right half side of the tuyere body 11.
• Each of the first reducing gas injection port 12 and the second reducing gas injection port 13 may penetrate any position in the wall of the tuyere body 11 so that the outlets 12ax, 13ax do not interfere with each other.
• the outlet 12ax of the first reducing gas injection port 12 may be located at any position in the upper half
• the outlet 13ax of the second reducing gas injection port 13 may be located at any position in the lower half
• both the outlet 12ax of the first reducing gas injection port 12 and the outlet 13ax of the second reducing gas injection port 13 may be located at any position in the upper half
• both the outlet 12ax of the first reducing gas injection port 12 and the outlet 13ax of the second reducing gas injection port 13 may be located at any position in the lower half.
• the height positions of the outlets 12ax, 13ax are divided into upper and lower, the distribution of the reducing gas concentration in the radial direction of the blast furnace 100 can be made more uniform.
• the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be higher than the height position P3 of the center of the outlet 13ax of the second reducing gas injection port 13.
• the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be higher than the height position P2 of the center of the opening 11ax of the tuyere body 11, and the height position P3 of the center of the outlet 13ax of the second reducing gas injection port 13 may be lower than the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the outlet 12ax of the first reducing gas blowing port 12 may be located at any position in the upper half
• the outlet 13ax of the second reducing gas blowing port 13 may be located at any position in the lower half.
• the outlet 12ax of the first reducing gas blowing port 12 and the outlet 13ax of the second reducing gas blowing port 13 may both be located at any position in the upper half, and the height position P1 of the center of the outlet 12ax of the first reducing gas blowing port 12 may be higher than the height position P3 of the center of the outlet 13ax of the second reducing gas blowing port 13.
• the outlet 12ax of the first reducing gas injection port 12 and the outlet 13ax of the second reducing gas injection port 13 may both be located somewhere in the lower half, and the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be higher than the height position P3 of the center of the outlet 13ax of the second reducing gas injection port 13.
• the hot air supplied from the hot air tuyere 10 into the blast furnace 100 may be, for example, air or oxygen-enriched air.
• the temperature of the hot air is, for example, 1000°C or higher.
• the temperature of the hot air may be 1000°C or higher and 2000°C or lower, 1000°C or higher and 1700°C or lower, 1000°C or higher and 1500°C or lower, or 1000°C or higher and 1300°C or lower.
• the flow velocity of the hot air at the opening 11ax of the tuyere body 11 may be appropriately adjusted depending on the operating conditions of the blast furnace 100, and may be, for example, 100 m/s or higher and 300 m/s or lower, or 200 m/s or higher and 250 m/s or lower.
• Reducing gas is a gas that functions as a reducing agent inside the blast furnace 100.
• the term "reducing gas” as used herein includes any gas that can generate a reducing agent (reducing component) by thermal decomposition inside the blast furnace 100.
• reducing gas include at least one selected from hydrogen gas, hydrocarbon gas (e.g., methane gas), carbon monoxide gas, ammonia gas, and alcohol gas (e.g., methanol gas or ethanol gas).
• At least one selected from coke oven gas (COG), converter gas (LDG), blast furnace gas (BFG), natural gas (NG), and synthesis gas (Syngas) may be used as the reducing gas.
• COG coke oven gas
• LDG converter gas
• BFG blast furnace gas
• NG natural gas
• Synngas synthesis gas
• the temperature of the reducing gas supplied from the first reducing gas injection port 12 and the second reducing gas injection port 13 to the inside of the blast furnace 100 may be, for example, 0°C or higher and 2000°C or lower, or 25°C or higher and 1500°C or lower.
• the flow velocity of the reducing gas at the outlet 12ax of the first reducing gas injection port 12 and the outlet 13ax of the second reducing gas injection port 13 may be, for example, lower than the sonic velocity at the operating temperature of each reducing gas.
• the flow velocity of the reducing gas at each of the outlet 12ax of the first reducing gas injection port 12 and the outlet 13ax of the second reducing gas injection port 13 may be 100 m/s or higher and 1000 m/s or lower.
• the flow velocity is 200 m/s or higher and 800 m/s or lower, ventilation inside the blast furnace 100 is stabilized, and operation in which the reduction reaction in the furnace proceeds stably is likely to be achieved.
• gases may be supplied together with the reducing gas from the first reducing gas supply port 12 and the second reducing gas supply port 13.
• gases include inert gases such as nitrogen gas.
• a method for supplying reducing gas to a blast furnace 100 includes: Hot air is supplied into the inside of the blast furnace 100 through the hot air tuyere 10 of the blast furnace 100, supplying a reducing gas into the blast furnace 100 through a first reducing gas injection port 12 penetrating the wall of the tuyere body 11 of the hot air tuyere 10 and a second reducing gas injection port 13 penetrating the wall of the tuyere body 11 at a position different from that of the first reducing gas injection port 12; Includes:
• reducing gas may be supplied to the hot air flow path 11a from each of the outlet 12ax of the first reducing gas injection port 12 and the outlet 13ax of the second reducing gas injection port 13.
• the height position P1 of the center of the outlet 12ax of the first reducing gas injection port 12 may be higher than the height position P2 of the center of the opening 11ax of the tuyere body 11, and the height position P3 of the center of the outlet 13ax of the second reducing gas injection port 13 may be lower than the height position P2 of the center of the opening 11ax of the tuyere body 11.
• the reducing gas may contain hydrogen gas.
• the technology of the present disclosure also has an aspect as a blast furnace tuyere.
• the blast furnace tuyere corresponds to the hot air tuyere 10 described above. That is, the blast furnace tuyere 10 according to one embodiment has a tuyere body 11, a first reducing gas injection port 12, and a second reducing gas injection port 13.
• the tuyere body 11 has a hot air flow path 11a
• the first reducing gas injection port 12 penetrates the wall of the tuyere body 11
• the second reducing gas injection port 13 penetrates the wall of the tuyere body 11 at a position different from the first reducing gas injection port 12.
• the iron oxide is reduced and dissolved by the reducing gas generated by the combustion of the coke, etc., and the reducing gas supplied from the first reducing gas injection port 12 and the second reducing gas injection port 13, thereby obtaining molten iron.
• the molten pig iron is tapped from a tap hole 102 provided at the bottom of the blast furnace 100.
• reducing gas is supplied into the blast furnace 100 through the first reducing gas injection port 12 and the second reducing gas injection port 13, thereby reducing the amount of carbon-containing reducing material such as coke used. As a result, the amount of CO2 generated can be reduced.
• the blast furnace 100 can have various configurations as long as it is capable of producing pig iron as described above.
• the blast furnace 100 may have other tuyere(s), ports, or lance(s) in addition to the hot blast tuyere 10 described above.
• the hot blast tuyere 10 may have other ports, lances, etc. in addition to the tuyere body 11, the first reducing gas injection port 12, and the second reducing gas injection port 13 described above.
• the hot blast tuyere 10 may have a pulverized coal injection lance, etc.
• the configuration of the blast furnace 100 other than the hot blast tuyere 10 is well known in the art, and therefore will not be described in detail here.
• the first reducing gas injection port 12 and the second reducing gas injection port 13 are used in combination as a means for supplying reducing gas into the interior of the blast furnace 100, and reducing gas is supplied from the multiple outlets 12ax, 13ax. This makes it possible to make the concentration distribution of the reducing gas in the radial direction of the interior of the blast furnace 100 more uniform than when reducing gas is supplied from only one outlet.
• first reducing gas injection port 12 and the second reducing gas injection port 13 are used in combination as a means of supplying reducing gas into the interior of the blast furnace 100, a larger amount of reducing gas can be supplied into the interior of the blast furnace 100, and the supply of reducing gas can be more easily stabilized, compared to when reducing gas is supplied via a single system.
• the present invention will be further described below with reference to examples, but the present invention is not limited to these examples.
• the present invention allows for various conditions to be adopted as long as the gist of the invention is not deviated from and the object is achieved.
• hydrogen gas is used as the reducing gas, but the type of reducing gas is not limited to this.
• the general-purpose thermal fluid analysis software FLUENT was used to perform a simulation taking into account gas flow, heat transfer, and chemical reactions, thereby evaluating the concentration of hydrogen molecules inside a blast furnace.
• the raceway region near the tuyere was treated as a cavity where no coke was present, and the coke-packed bed region in the blast furnace away from the raceway was treated as a porous medium.
• the standard k- ⁇ model was used for turbulence analysis, the vortex dissipation model for gas combustion, and the Field's model for the gasification reactions of O 2 , CO 2 , and H 2 O from the coke.
• FIG. 6A shows the hydrogen concentration distribution in the above case (1)
• Figure 6B shows the hydrogen concentration distribution in the above case (2)
• Figure 6C shows the hydrogen concentration distribution in the above case (3).
• the hydrogen concentration distribution was normalized by the average hydrogen mole fraction at a height of 12 m from the center of the tuyere.
• the bias in hydrogen concentration within the furnace varies depending on the means and position of hydrogen gas supply.
• the hydrogen concentration is high between the furnace wall and the center of the blast furnace.
• the hydrogen concentration is high on the wall side and in the furnace center of the blast furnace.
• the hydrogen concentration is high in the area near the furnace wall between the furnace wall and the center of the blast furnace.
• the hydrogen concentration distribution in the radial direction of the blast furnace can be averaged and made uniform.
• case (1) and case (2) above i.e., by using multiple hydrogen injection ports in combination, it is believed that the hydrogen concentration distribution in the radial direction of the blast furnace can be made more uniform.
• supplying hydrogen gas through two systems reduces the bias in the hydrogen concentration distribution in the radial direction inside the blast furnace compared to when hydrogen gas is supplied through a single system.
• a hot blast tuyere of a blast furnace has a tuyere body, a first reducing gas injection port, and a second reducing gas injection port.
• the tuyere body has a hot air flow path.
• the first reducing gas injection port penetrates the wall of the tuyere body;
• the second reducing gas injection port penetrates the wall of the tuyere body at a different location than the first reducing gas injection port.

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• 2025
  • 2025-04-15 JP JP2025546916A patent/JP7849649B2/ja active Active
  • 2025-04-15 WO PCT/JP2025/014761 patent/WO2025225450A1/ja active Pending
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