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WO2020171079A1 - Installation de fabrication de fer à réduction directe - Google Patents

Installation de fabrication de fer à réduction directe Download PDF

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Publication number
WO2020171079A1
WO2020171079A1 PCT/JP2020/006333 JP2020006333W WO2020171079A1 WO 2020171079 A1 WO2020171079 A1 WO 2020171079A1 JP 2020006333 W JP2020006333 W JP 2020006333W WO 2020171079 A1 WO2020171079 A1 WO 2020171079A1
Authority
WO
WIPO (PCT)
Prior art keywords
chute
furnace
reduced iron
hdri
cooling furnace
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2020/006333
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English (en)
Japanese (ja)
Inventor
理彦 鉄本
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Kess LLC
Original Assignee
Kess LLC
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Kess LLC filed Critical Kess LLC
Publication of WO2020171079A1 publication Critical patent/WO2020171079A1/fr
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/02—Making spongy iron or liquid steel, by direct processes in shaft furnaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27B—FURNACES, KILNS, OVENS OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
    • F27B1/00—Shaft or like vertical or substantially vertical furnaces
    • F27B1/10—Details, accessories or equipment specially adapted for furnaces of these types
    • F27B1/21—Arrangements of devices for discharging
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F27—FURNACES; KILNS; OVENS; RETORTS
    • F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
    • F27D15/00—Handling or treating discharged material; Supports or receiving chambers therefor
    • F27D15/02—Cooling

Definitions

  • the present invention relates to a direct reduced iron production facility, and more particularly to a direct reduced iron production facility characterized by the structure of a chute connecting a reduction furnace and a cooling furnace.
  • the direct reduction ironmaking method typically introduces a reducing gas containing hydrogen and carbon monoxide as main components into a vertical reduction furnace to reduce the iron oxide and oxidize it. It is represented by the Midrex method of producing metallic iron by reducing iron in the solid phase.
  • the reducing gas uses water vapor and carbon dioxide (CO 2 ) as oxidants, and a hydrocarbon-containing gas such as natural gas whose main component is methane (CH 4 ) is an external heating type reformer ( It is manufactured by reforming under high temperature.
  • a hydrocarbon-containing gas such as natural gas whose main component is methane (CH 4 ) is an external heating type reformer ( It is manufactured by reforming under high temperature.
  • Reduced iron is obtained by charging iron oxide into a vertical reduction furnace and contacting it with this high-temperature reducing gas.
  • a cooling zone is provided below the reduction zone to cool the reduced iron and discharge it from the lower portion of the furnace.
  • HDIR high-temperature reduced iron
  • CDRI cooled reduced iron
  • the direct reduced iron production facility is divided into an upper reduction furnace and a lower reduced iron cooling furnace (cooling furnace), and HDRI is provided at the outlet of the upper reduction furnace.
  • HDRI is discharged from the reduction furnace in the upper part
  • CDRI is simultaneously discharged from the cooling furnace in the lower part.
  • the upper reduction furnace and the lower cooling furnace are connected by a chute, but this chute not only supplies the desired reduced iron to the cooling furnace, but also reduces the massive reduced iron and drops it from the inside of the furnace. It is necessary to be able to discharge the refractory and the dropped furnace parts, and the diameter of the chute must be larger than the diameter necessary to supply the reduced iron. In addition, it is necessary to move the gas of the reducing furnace and the cooling furnace back and forth through this chute as needed. At this time, the flow velocity of the gas is set to a predetermined speed or less so as not to hinder the fall of the reduced iron. A chute with a caliber that can be used is required.
  • the reduction furnace in the upper part and the cooling furnace in the lower part are separately supported from the structure, and it is necessary to absorb the thermal expansion. Also, it is necessary to absorb the thermal expansion of the chute itself. For this reason, it is necessary to install an expansion joint for absorbing thermal expansion in the chute or the connecting portion between the chute and the furnace (reduction furnace and/or cooling furnace).
  • the lower cooling furnace and the upper reducing furnace are connected by a chute, and when reducing iron is discharged from the lower cooling furnace, only the volume of the reduced iron discharged from the cooling furnace is removed from the upper reducing furnace. It is desired that hot reduced iron (HDIR) be stably replenished.
  • HDIR hot reduced iron
  • the diameter of the cooling furnace is determined by the cooling capacity, it is not realistic to reduce the diameter of the cooling furnace in order to reduce the volume determined by the angle of repose and the collapse angle.
  • the size of the chute is as described above when the mass of reduced iron, the crushing device for crushing it, etc. is dropped. It is also necessary to make the size of these parts and the refractory material that has fallen out of the furnace without being clogged by this chute, and it is not preferable to reduce the chute diameter from the viewpoint of stable operation.
  • the present invention has been made in order to solve the above problems, in a chute connecting the reduction furnace installed in the upper part and the cooling furnace installed in the lower part, in addition to supplying desired reduced iron
  • the reduced iron, the refractory that has fallen out of the furnace, and the parts inside the furnace can be discharged without being blocked by the chute, and a desired gas is moved between the reducing furnace and the cooling furnace.
  • Damage to the chute and the expansion joint installed on the chute that has a sufficient size to prevent the reduction of reduced iron at the gas flow rate and eliminates the problem of vibration that accompanies the fall of the raw material. It is an object of the present invention to provide a chute that has a structure capable of preventing the above, and can stably drop and supply HDRI without being dropped or supplied all at once.
  • the direct reduced iron production facility of the present invention includes a reduction furnace, a cooling furnace provided below the reduction furnace, and a chute that connects the reduction furnace and the cooling furnace.
  • the chute includes a main chute whose lowermost end is open inside the cooling furnace, and the raw material can be supplied to a region other than a region formed by projecting the vertical cross section of the lower end of the main chute onto a horizontal plane.
  • the chute comprises at least one opening or branch pipe provided in the main chute.
  • a notch is provided at the lower end of the main chute.
  • the direct reduced iron production facility of the present invention is provided with a main chute corresponding to the chute provided in the conventional direct reduced iron production facility.
  • This main chute has a sufficient size in consideration of lumped reduced iron and fallen objects dropped from the furnace.
  • the HDRI supplied from the large-diameter main chute is stably supplied as the HDRI immediately below the HDRI drops.
  • lumped reduced iron and fallen objects dropped from the furnace are also discharged from the open end of this main chute.
  • the gas flow velocity can be set to be equal to or lower than the desired flow velocity.
  • the HDRI is supplied to the surface layer determined by the repose angle and collapse angle of the reduced iron in the cooling furnace through at least one opening or branch pipe provided in the main chute, and the HDRI supply rate is the opening or branch pipe. Limited by Therefore, it is possible to prevent the HDRI from being supplied all at once, and it is possible to prevent vibration of the chute and damage to the chute and the expansion and contraction joints due to the supply of HDRI.
  • the supply rate of HDRI depends on the area where the raw material is supplied during the collapse.
  • the raw material in the case of a circular or vertical chute, when the raw material collapses from the vertical chute, the raw material is supplied from the area surrounded by the thickness of the collapsing layer in the chute portion and the edge (circumference) of the chute.
  • an elliptical opening is provided on the side surface of the main chute, the total area enclosed by the collapse layer and the elliptical opening at the opening is supplied. This limits the feed rate from the openings or branch pipes compared to when they are not installed.
  • the raw material layer surface does not move all the way to the collapse angle all at once because there is a height difference between the open end portion of the opening or the branch pipe and the portion that is not the open end of the opening or the branch pipe, HDRI is gradually supplied.
  • the direct reduced iron production facility of the present invention by adopting the above chute, reduced iron is supplied on average from the reducing furnace to the cooling furnace without being supplied all at once, and a chute connecting the reducing furnace and the cooling furnace. Vibration can be prevented. Therefore, it is possible to prevent damage to the expansion joint and the chute itself connected to the chute.
  • the size of the main chute can be arbitrarily and appropriately determined depending on the size of the assumed reduced lumped reduced iron, the substances dropped from the furnace, and the gas flow rate, and stable operation can also be achieved. ..
  • FIG. 1 It is a schematic diagram of the whole direct reduction iron manufacturing equipment structure. It is explanatory drawing which shows the structure of the chute (multi-hole chute) of Embodiment 1 of this invention, and the state of a cooling furnace. It is a figure which shows the modification of the chute and cooling furnace of Embodiment 1 of this invention. It is explanatory drawing which shows the structure of the chute (branch pipe holding chute of a furnace installation type) of Embodiment 2 of this invention, and the state of a cooling furnace, (a) is a side view, (b) is CC of (a). It is a line end view.
  • FIG. 1 shows a schematic diagram of the entire structure of a direct reduced iron manufacturing facility, that is, a vertical type direct reduced iron manufacturing furnace (reduction furnace) and a reduced iron cooling furnace (cooling furnace).
  • a direct reduced iron manufacturing facility that is, a vertical type direct reduced iron manufacturing furnace (reduction furnace) and a reduced iron cooling furnace (cooling furnace).
  • the expansion and contraction joints provided at the connecting portion between the chute and the reduction furnace and the cooling furnace are omitted.
  • the direct reduced iron manufacturing facility 10 includes a reduction furnace 2 installed in an upper part, a cooling furnace 4 installed in a lower part, and a chute 3 connecting the reduction furnace 2 and the cooling furnace 4.
  • the chute 3 is branched into a first pipe 31 and a second pipe 32 by a branch portion 3a.
  • One first pipe 31 is connected to the cooling furnace 4, and the other second pipe 32 is an exhaust pipe for exhausting high-temperature reduced iron (HDIR) from the reducing furnace 2.
  • HDIR high-temperature reduced iron
  • a raw iron oxide supply conveyor 1 for supplying the raw iron oxide is provided above the reduction furnace 2.
  • An HDRI discharge conveyor 6 for discharging HDRI is provided below the second pipe 32, and a CDRI discharge conveyor 5 for discharging reduced temperature iron (CDRI) at room temperature is provided below the cooling furnace 4. It is provided.
  • the raw iron oxide is supplied to the reduction furnace 2 via the raw iron oxide supply conveyor 1.
  • the raw material iron oxide is reduced with a high-temperature reducing gas supplied from a reducing gas production device (not shown).
  • the reduced HDRI is supplied to the cooling furnace 4 via the chute 3.
  • the HDRI is cooled in the cooling furnace 4 by a cooling gas supplied from a cooling gas manufacturing apparatus (not shown), and is discharged as CDRI by the CDRI discharging conveyor 5.
  • the HDRI is discharged from the second pipe 32 (discharge pipe) of the chute 3 and conveyed to a predetermined position (not shown) via a device such as the HDRI discharge conveyor 6.
  • the chute 3 includes a main chute 31.
  • the main chute 31 is similar to the chute provided in the conventional direct reduced iron manufacturing facility, and corresponds to the first pipe 31 described above.
  • the main chute 31 has an axial cross-sectional area smaller than the maximum axial cross-sectional area of the reduction furnace 2, and has a minimum axial cross-sectional area of a size that allows a fallen substance from the reduction furnace 2 to pass through. ing.
  • the perpendicular cross-sectional area through which the falling material from the reduction furnace 2 can pass is, for example, 300 mm or more in diameter.
  • the lower end of the main chute 31 is an open end 31a, which is open inside the cooling furnace.
  • the main chute 31 is provided with a plurality of openings 36 on its side surface.
  • the opening 36 has an elliptical shape.
  • the HDRI is supplied from the gaps above the large number of openings 36, the HDRI is first supplied to the collapse angle (the slope B1 formed by the collapse angle) at the opening 36, and a part of the HDRI does not exist in the range where the opening 36 exists. It will be in a flowing state. As a result, the HDRI is supplied little by little, and the HDRI that has been intermittently supplied is averaged and almost no vibration is observed.
  • the main chute 31 is of a size sufficient to allow falling objects to pass therethrough, and since the lower end of the main chute 31 is kept open, lumped reduced iron, crusher parts, refractories, etc. The large mass is discharged from the open end 31a at the lower end of the main chute 31 without any problem.
  • the flow velocity of the gas can be controlled to the flow velocity as planned, and the inhibition of the drop of HDRI caused by the excessive rise of the flow velocity can be suppressed.
  • the opening 36 has an elliptical shape.
  • the shape of the opening 36 is not limited to this, and any shape such as a rectangle, a triangle, an inverted triangle, a circle, a rhombus, or a trapezoid can provide the same effect. ..
  • the upper portion of the opening 36 into a semicircular shape or a notch shape so that the range of the opening 36 gradually expands as the HDRI falls, the supply of HDRI is further averaged and vibration is further suppressed.
  • the present invention is not limited to this, and as shown in FIG. 3, a notch 38 is provided in the lower end portion of the main chute 31 instead of the opening 36. Even if it is provided, the same effect can be obtained because the range where the reduced iron flows in is reduced. Both the opening 36 and the notch 38 may be provided, or either one may be provided.
  • the chute 3 includes the same main chute 31 as that of the first embodiment.
  • the main chute 31 is provided with the branch pipes 37 at the plurality of openings formed in the side circumferential surface.
  • the size of the branch pipe 37 is such that the total perimeter of the open end of the branch pipe is shorter than the perimeter of the main chute.
  • the HDRI is also supplied from the branch pipe 37 to the inside of the cooling furnace 4, so that the HDRI supply portion can be dispersed on the outer peripheral side of the cooling furnace 4.
  • the HDRI is supplied from the plurality of branch pipes 37, and the total perimeter of the open ends of the branch pipes 37 is shorter than the perimeter of the main chute. Even if the balance is lost in the vicinity of the slope A2) formed by and the HDRI flows into the collapse angle (slope B2 formed by the collapse angle), the supply range is sufficiently smaller than that of the main chute 31 and the raw material does not flow at once. Lost. That is, HDRI is first supplied up to the collapse angle (slope B2 formed by the collapse angle) in the branch pipe 37, and a part of the HDRI flows into the area where the branch pipe 37 does not exist. As a result, HDRI is supplied on average and does not cause vibration.
  • the raw material supply points are dispersed on the outer peripheral side of the cooling furnace 4, it is possible to prevent the raw material powder from being excessively segregated immediately below the main chute 31. As a result, the cooling gas flows evenly throughout the cooling furnace 4, and the problem of partial cooling shortage is solved.
  • the branch pipe 37 may be further provided with an opening, or a cutout may be provided at the lower end (open end) of the branch pipe 37. This makes it possible to supply HDRI more stably.
  • the chute 3 includes a main chute 31 similar to that of the first embodiment.
  • the main chute 31 is provided with branch pipes 37 at a plurality of openings formed in the side peripheral surface thereof.
  • the branch pipe 37 is provided so as to be inserted into the cooling furnace 4 from above the cooling furnace 4. Inside the cooling furnace 4, the branch pipe 37 is arranged vertically to the cooling furnace 4.
  • the process effect is satisfied, since the branch pipe 37 is installed inside the cooling furnace 4, there is a drop due to the wear of the branch pipe 37 itself, CDRI discharge failure occurs, and maintenance is not performed. Therefore, there was a problem that the entire plant had to be stopped.
  • the third embodiment by arranging the branch pipe 37 from the upper portion of the cooling furnace 4, the wear of the branch pipe 37 inside the cooling furnace 4 is reduced, and most of the maintenance is performed from the outside of the cooling furnace 4. It is possible to improve the utilization rate.
  • the supply of HDRI to the surface layer determined by the repose angle and the collapse angle of the reduced iron in the cooling furnace is provided in at least one of the main chutes. It is made from an opening or a branch pipe, and the supply rate of HDRI is limited by the opening or the branch pipe. Therefore, it is possible to prevent the HDRI from being supplied all at once, and it is possible to prevent vibration of the chute and damage to the chute and the expansion and contraction joints due to the supply of HDRI.
  • a main chute 31 of sufficient size is provided in consideration of the axial cross-sectional area through which the falling material from the reduction furnace 2 can pass, that is, the reduced iron that has become a lump and the falling material that has fallen out of the furnace.
  • the reduced iron supplied from the large-diameter main chute 31 is stably and gradually continuously supplied as the reduced iron immediately below the reduced iron falls.
  • the reduced iron that has become a lump and the fallen objects that have fallen out of the furnace are also discharged from the main chute 31.
  • the thermal expansion is absorbed by the expansion joint 7.
  • the HDRI is cooled by the cooling gas and then discharged by the CDRI discharge conveyor 5.
  • the ridgeline of HDRI in the upper part of the cooling furnace 4 gradually changes from the collapse angle (slope B formed by the collapse angle) to the ridgeline near the repose angle (slope A formed by the repose angle), and the balance is lost.
  • HDRI flows all the way to the collapse angle and repeats.
  • the expandable joint 7 and the chute 3 start to vibrate due to the external force of HDRI that flows in at once, and the expandable joint 7 functions as a spring, so that the vibration is not reduced and the chute 3 and the expandable joint 7 are damaged.
  • the reduced iron in the cooling furnace 4 is supplied to the surface layer determined by the repose angle and the collapse angle from the plurality of openings 36 or the branch pipes 37 provided in the chute 3.
  • the total area that can be supplied from the opening 36 or the branch pipe 37 is smaller than the circumferential length of the open end 31a of the main chute 31 and the area formed by the collapsing layer. Limited by tube 37.
  • the surface of the raw material layer has a height difference between the opening 36 or the branch pipe 37 portion and the portion not having the opening 36 or the branch pipe 37, the entire surface of the cooling furnace 4 does not shift to the collapse angle all at once, and the HDRI Is gradually supplied. Therefore, it is possible to prevent the HDRI from being supplied all at once, and to prevent vibration of the chute 3 and the expansion joint 7 provided on the chute 3 due to this, and also to prevent damage to the chute 3 and the expansion joint 7.
  • the main chute 31 is formed with a size sufficient to realize an appropriate flow velocity that does not prevent the reduction of the reduced iron, it is possible to move a required gas amount between the reduction furnace 2 and the cooling furnace 4.
  • the gas flow rate can also be maintained at the gas flow rate as originally planned.
  • the chute 3 has a configuration in which the opening 36 or the branch pipe 37 is provided in the main chute 31, but the configuration of the chute 3 is not limited to each of the above-described embodiments. That is, the chute 3 may include the opening 36 and the branch pipe 37 in the main chute 31. Further, the chute 3 can take any form as long as the raw material can be supplied to a region other than the region formed by projecting the axial cross section of the lower end of the main chute 31 onto a horizontal plane.
  • the area formed by projecting on the horizontal plane means an area formed by intersecting the horizontal plane with the axial cross section of the lower end portion of the main chute 31 extending in the axial direction of the main chute 31.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Charging Or Discharging (AREA)

Abstract

Le problème décrit par la présente invention est de fournir une goulotte reliant un four de réduction et un four de refroidissement l'un à l'autre, moyennant quoi il devient possible de fournir le fer réduit souhaité, d'évacuer du fer réduit agrégé, des réfractaires détachés de l'intérieur du four et des composants présents dans le four sans obstruer la goulotte avec ces matériaux, d'obtenir un débit de gaz qui ne peut pas inhiber la chute du fer réduit, et d'éliminer les vibrations qui peuvent se produire en association avec la chute de matières premières dans la goulotte. La solution selon la présente invention porte sur une installation de fabrication de fer à réduction directe qui est pourvue : d'une goulotte principale qui a une taille suffisante, déterminée en prenant en compte l'évacuation du fer réduit agrégé, des réfractaires détachés de l'intérieur d'un four et des objets chutant tels que des composants présents dans le four et en prenant également en compte le débit d'un gaz traversant la goulotte ; et d'au moins un orifice d'ouverture ou un tube de ramification qui est disposé dans la goulotte principale.
PCT/JP2020/006333 2019-02-19 2020-02-18 Installation de fabrication de fer à réduction directe Ceased WO2020171079A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2019027354 2019-02-19
JP2019-027354 2019-02-19

Publications (1)

Publication Number Publication Date
WO2020171079A1 true WO2020171079A1 (fr) 2020-08-27

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PCT/JP2020/006333 Ceased WO2020171079A1 (fr) 2019-02-19 2020-02-18 Installation de fabrication de fer à réduction directe

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6137329B2 (fr) * 1982-11-15 1986-08-23 Korufu Eng Gmbh
JP2001152222A (ja) * 1999-11-30 2001-06-05 Nippon Steel Corp 還元炉の排出装置
JP2003041310A (ja) * 2001-07-27 2003-02-13 Kobe Steel Ltd 溶融金属の製造方法
US20090051083A1 (en) * 2005-04-22 2009-02-26 Arbeno Vrech Reduction furnace

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS6137329B2 (fr) * 1982-11-15 1986-08-23 Korufu Eng Gmbh
JP2001152222A (ja) * 1999-11-30 2001-06-05 Nippon Steel Corp 還元炉の排出装置
JP2003041310A (ja) * 2001-07-27 2003-02-13 Kobe Steel Ltd 溶融金属の製造方法
US20090051083A1 (en) * 2005-04-22 2009-02-26 Arbeno Vrech Reduction furnace

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