US3764299A - Process of operating a blast furnace by varying gaseous feed rates - Google Patents

Process of operating a blast furnace by varying gaseous feed rates Download PDF

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Publication number
US3764299A
US3764299A US00146914A US3764299DA US3764299A US 3764299 A US3764299 A US 3764299A US 00146914 A US00146914 A US 00146914A US 3764299D A US3764299D A US 3764299DA US 3764299 A US3764299 A US 3764299A
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Prior art keywords
blast
gas
furnace
air
blown
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Expired - Lifetime
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US00146914A
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English (en)
Inventor
W Wenzel
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JFE Engineering Corp
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Nippon Kokan Ltd
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Priority claimed from DE19702030468 external-priority patent/DE2030468C3/de
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B5/00—Making pig-iron in the blast furnace
    • C21B5/06—Making pig-iron in the blast furnace using top gas in the blast furnace process
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B65—CONVEYING; PACKING; STORING; HANDLING THIN OR FILAMENTARY MATERIAL
    • B65G—TRANSPORT OR STORAGE DEVICES, e.g. CONVEYORS FOR LOADING OR TIPPING, SHOP CONVEYOR SYSTEMS OR PNEUMATIC TUBE CONVEYORS
    • B65G47/00—Article or material-handling devices associated with conveyors; Methods employing such devices
    • B65G47/34—Devices for discharging articles or materials from conveyor 
    • B65G47/46—Devices for discharging articles or materials from conveyor  and distributing, e.g. automatically, to desired points
    • B65G47/50—Devices for discharging articles or materials from conveyor  and distributing, e.g. automatically, to desired points according to destination signals stored in separate systems
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B19/00—Programme-control systems
    • G05B19/02—Programme-control systems electric
    • G05B19/04—Programme control other than numerical control, i.e. in sequence controllers or logic controllers
    • G05B19/07—Programme control other than numerical control, i.e. in sequence controllers or logic controllers where the programme is defined in the fixed connection of electrical elements, e.g. potentiometers, counters, transistors
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
    • C21B2100/40—Gas purification of exhaust gases to be recirculated or used in other metallurgical processes
    • C21B2100/44—Removing particles, e.g. by scrubbing, dedusting
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
    • Y02P10/122—Reduction of greenhouse gas [GHG] emissions by capturing or storing CO2
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
    • Y02P10/143—Reduction of greenhouse gas [GHG] emissions of methane [CH4]
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • ABSTRACT OF THE DISQLOSURE A method of operating a blast-furnace comprising blowing into the furnace a gaseous auxiliary reduction medium, such as reducing gas, at a level above the blast tuyeres and substantially above the zone in which the burden melts down, While simultaneously blowing in blast air through the blast tuyeres, wherein the feed rate of said reduction medium and the feed rate of said blast air are both periodically varied, each between a maximum and a minimum value, said feed rates being matched, one to the other, to provide a substantially constant rate of production of top gases and to give an optimum gas velocity at the top of the furnace.
  • a gaseous auxiliary reduction medium such as reducing gas
  • This invention relates to blast-furnaces and their operation.
  • the present invention consists in providing a method which enables the reducing gases that are to be blown in to be introduced considerably more deeply into the blast-furnace, it also being possible for such gases to reach the middle zone.
  • the method of the invention consists in periodically varying, between a maximum and a minimum, the quantities of gas which are to be blown simultaneously into the blast furnace and Which consists of the combustion blast to be introduced through the blast-air tuyeres, and the auxiliary reducing gas to be blown in at a higher level through separate elements.
  • An important feature of this invention is that the rate of production of to gas is kept at high level by means of suitable interrelated elements for controlling the two streams of gas fed to the blastfurnace so that this rate is practically constant and represents the maximum quantity of gas that can flow from the furnace top without disadvantageous effects due to excessive gas velocity.
  • the optimum conditions for blowing in two gaseous media, and particularly the blast air may render it necessary not to reduce the quantity of gas periodically to zero, but to a minimum value which can be for example 20% of the maximum input. This is particularly necessary as regards blowing the air through the blast air tuyeres of the blast-furnace, since otherwise there might arise the danger of molten constituents from the interior of the furnace, particularly molten slag, entering the blast tuyeres and stopping them up.
  • a further important feature of the invention consists in maintaining, in the furnace stack, specific temperatures at which optimum effects as regards the performance of the blast-furnace can be obtained.
  • the position at which the auxiliary reducing gas is blown into the stack is so selected that this gas is introduced into the blastfurnace just above the zone at which melting of the ore or of the spongy iron resulting from the ore takes place.
  • the gases rising through the smelting zone from the well of the blast-furnace have a temperature of roughly 1200 to 1300 C. at this point.
  • the blown-in auxiliary gases have the effect of reducing this temperature as rapidly as possible to a value of about 1000 C. as a result of mixing with the auxiliary gases.
  • This step offers the important advantage of restricting to the maximum extent, by direct reduction, the coke-consumption zone which attains a temperature of approximately 1000 C., so that a saving in coke is effected.
  • this rapid cooling of the stack gases is also achieved by blowing in an auxiliary gas of appropriately low temperature, 800 C. for example.
  • the temperature of the stack contents located above the fusion zone is periodically raised by the ascending well gases during the period in which the blast air is being injected at maximum rate, and thereafter are cooled again to the required lower temperature limit during the period in which the reducing gases are blown in.
  • the top gas is the various portions of the blow-in period is put to different uses depending upon the particular quality of the gas.
  • the gas to be regenerated can be drawn off during the portion of the period in which auxiliary reducing gas is blown in.
  • the top gas can be passed to a water scrubber and/or carbon dioxide scrubber and/or it can be chemically regenerated by chemical reaction with fossil fuels such as oil or methane, and blown into the blast furnace stack again after heating to about 800 C.
  • the top gas for heating the regenerators in which the air blast for the furnace is raised to temperatures of 1100 C.
  • a step in the method of the invention that is of importance from the point of view of economics consists in the joint operation of two or more adjacent blast-furnaces operating in accordance with the same process.
  • This joint operation can consist in using low-grade top gases from one of the blast-furnaces for heating the air blast for the other blast-furnaces, if possible without storing the gas; on the other hand, highgrade top gases from such a blast-furnace can be used after regeneration as an auxiliary reducing gas in one or more neighbouring blast-furnaces.
  • oxygen-enriched air or concentrated oxygen are used with water vapour and/or carbon dioxide as the blast air for the furnace.
  • a particularly simple embodiment of the invention consists in using only one regenerator in each case for preheating the combustion air blast and/or for heating the auxiliary reduction gas, and in matching the heating-up and heat delivery period of the regenerator to the period required for blowing the heated medium in question into the blast furnace.
  • such gas-production methods are adapted to suit the blast-furnace process by matching the working periods during which the gas is produced on a timedependent basis to the blow-in periods of the blastfurnace, taking into account the gas-quantity/time function of said periods.
  • methane can be reacted with water vapour in a regenerator, gas production being adjusted to the requirements of the blastfurnace.
  • FIG. 1 shows schematically a blast-furnace and associated equipment
  • FIG. 2 shows a tuyere
  • a blast-furnace is shown schematically at 1; the burden 2, consisting of ore, coke and fluxing materials is introduced at the top of the furnace, i.e. at the stack.
  • the molten products 3, that is, pig iron and slag, are drawn off from the well of the blast-furnace.
  • the hot blast air 4 is injected at the level of the blast tuyeres of the furnace.
  • the streams of top gas 5:: and 5b escape through the top of the furnace.
  • the melting-down zone 6 in which the primary iron and primary slag are melted down by means of the hot well gases rising from the level of the blast tuyeres, the primary iron and primary slag then flowing into the lower furnace.
  • the arrangement shown in FIG. 1 also includes a gas scrubbing installation 11 of known construction, in which, by known methods, carbon dioxide and/or water vapour are washed out of a part-stream 12 of the top gas 5a and are exhausted into a duct 13. If, in the gas scrubbing installation 11, a process is carried out that requires a heating operation, the heating gas 14 necessary for this is drawn as a part-stream from the top gas 5b and is combusted with air which is not shown separately in this sketch. The resultant burned gas is exhausted from the scrubbing installation 11 through the duct 15.
  • Reducing gas 16 from an outside source is optionally jointly introduced into the top gas scrubbing installation 11 with the part-stream 12 of the top-gas 5b that is to be scrubbed, said reducing gas 16 being produced in known manner from f ssil fuels and separately from the blast-fur ace plant here illustrated, and the reducing gas also contains fairly large quantities of water vapour and/or carbon dioxide.
  • the reduction gas is heated in this installation 18 preferably on a recuperative basis.
  • the heating gas used is constituted by a part-stream 19 of the top gas b which is combusted with air not shown separately in this sketch.
  • the burned gas occurring during combustion is exhausted from the gas-heating installation 18 through the duct 20.
  • reducing gas 21 from an outside source which is produced in known manner from fossil fuels separately from the blast-furnace plant shown in FIG. 1 and which is already largely free from carbon dioxide and water vapour, is heated together with the scrubbed reduction gas 17.
  • FIG. 1 also shows the control elements 23 to 27 in the various gas ducts.
  • the purpose of the regulating element 23 is to take off from the low-nitrogen top gas stream 5a, the stream of reducing gas that is required by the blast-furnace 1 and is passed through the gas scrubbing installation 11 and the gas heater 18 and is blown into the stack of the blast-furnace as hot reducing gas 22.
  • the purpose of the regulator 27 is to adjust the quantity of cold blast air to the required level for blowing hot blast air 4 into the tuyeres of the blast-furnace 1.
  • the regulating elements 24, 25 and 26 adjust the flow of hot gas from the hot-gas collecting duct 29 to the quantity required by the gas scrubbing installation 11, the gas heater 18 and the blast-air heater 7.
  • a particular feature of the invention is constituted by the fact that the gas regulator 23 periodically releases a maximum quantity of reducing gas, whilst at the same time the regulator 27 passes a minimum quantity of blast air to the blast-air heater 7. After a certain blow-in period in this condition, the system is reversed, and the regulator 23 brings the quantity of reducing gas down to a minimum, whereas at the same time the regulator 27 raises the quantity of blast air to a maximum.
  • special measures are employed for blowing in the blast air. Since the quantity of blast air is periodically reduced from a maximum quantity to a minimum quantity which can be 20% or less of the maximum quantity, special means are used to ensure that the depth of penetration of the blast air into the charge of the blast-furnace remains sufficiently great. The required depth of penetration is ensured by maintaining the velocity of the blast air at substantially the same level when it enters the furnace chamber, both when the maximum and minimum quantities of blast air are blown in. For this purpose, it is necessary to suit the injection cross-section to the quantities of blast air.
  • FIG. 2 An advantageous arrangement for this latter purpose is illustrated in FIG. 2.
  • This schematic illustration shows a blast-furnace tuyere 30 through which water flows and which has a blow-in cross-section 31.
  • the blast-air supply pipe 32 runs to the tuyere 30.
  • Lateral pockets 33 and 33a are fitted to this supply pipe 32.
  • Contained in the pockets are slides 34 and 34a which are preferably made of ceramic material and can be moved into or out of the blast-air supply pipe 32 by means of rods 35 and 35a.
  • rods 35 and 35a In the upper portion of the drawing, is illustrated the position of the blast-air injection device with the slide 34 retracted, while in the lower part of the slide 34a is shown in the pushed-in position.
  • the pipe 36 for supplying auxiliary blast air In the middle of the blast-air supply pipe 32 is the pipe 36 for supplying auxiliary blast air, this pipe being supported or centered on stands 39.
  • the slides 34 and 34a In the pushed-in position, the slides 34 and 34a each lie closely against the surface of the pipe 36 at the blast inlet end 37. In the retracted position of the slides 34 and 34a, the stream 40 of blast air can pass freely over the entire cross-section of the supply pipe 32, including the middle pipe 36.
  • the slides 34 and 34a When the slides 34 and 34a are pushed in, they close off the annular chamber round the middle pipe 36, so that the stream 40 of blast air can only be supplied to the mouth 31 of the blast tuyere through the middle pipe 36.
  • a method of operating a blast-furnace containing a plurality of peripherally spaced blast tuyeres, and a plurality of peripherally spaced auxiliary tuyeres positioned at a level above the blast tuyeres and substantially above the zone in which the burden melts down comprising blowing an auxiliary reducing gas through said auxiliary tuyeres while simultaneously blowing blast air through the blast tuyeres, and periodically varying the feed rate of said auxiliary reducing gas through each of said auxiliary tuyeres between maximum and minimum values, and periodically vary the feed rate of said blast air between maximum and minimum values, said feed rates being (i) varied in oppo site directions so that when the feed rate of blast gas to blast tuyeres is at a maximum the feed rate of auxiliary reducing gas to auxiliary tuyeres is at a minimum, and vice versa, and (ii) matched with respect to each other to provide a substantially constant rate of production of top gas and to give an optimum gas
  • top gas which is to be used for heating blast air is drawn off from the top gas stream during the period in which the blast air is blown into the furnace at maximum rate.
  • regenerators are used for heating the blast air and the auxiliary reducing gas, and only one generator being used for each purpose.
  • a method as specified in claim 8 in which the duration of the periods of time during which, respectively, the auxiliary reducing gas and the blast air are blown into the furnace at their maximum rate are so matched that while the blast air is blown in at maximum rate the material in the process of being melted is held up by the upward stream, and While the auxiliary reducing gas is blown in at maximum rate the melted material flows down as a result of the corresponding reduction in the flow rate of the blast air.
  • auxil- 8 obviouslyy reducing gas is produced by reacting at least one fuel from the group consisting of natural gas and petroleum with an oxygen containing medium outside of the blast furnace.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Iron (AREA)
US00146914A 1970-06-20 1971-05-26 Process of operating a blast furnace by varying gaseous feed rates Expired - Lifetime US3764299A (en)

Applications Claiming Priority (1)

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DE19702030468 DE2030468C3 (de) 1970-06-20 Verfahren zum Betrieb von Hochöfen mit Hilfsreduktionsgasen

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US (1) US3764299A (enExample)
AT (1) AT325075B (enExample)
BE (1) BE767715A (enExample)
FR (1) FR2095390B1 (enExample)
GB (1) GB1334174A (enExample)
IT (1) IT940424B (enExample)
LU (1) LU63311A1 (enExample)
NL (1) NL157056B (enExample)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3904398A (en) * 1972-08-22 1975-09-09 Centre Rech Metallurgique Manufacturing pig iron in a blast furnace
US3955963A (en) * 1973-05-18 1976-05-11 Centre De Recherches Metallurgigues-Centrum Voor Research In De Metallurgie Method of reducing ore
US4047935A (en) * 1974-12-11 1977-09-13 United States Steel Corporation Process for direct-reduction of iron-ore employing nuclear reactor-powdered catalytic reformer
US20080237944A1 (en) * 2005-11-09 2008-10-02 Thyssenkrupp At.Protec Gmbh Method For Operating a Shaft Furnace, and Shaft Furnance Operable By That Method
EP2426223A4 (en) * 2009-04-30 2015-03-18 Jfe Steel Corp PROCESS FOR USING A HIGH-STOVE, ASSOCIATED METHOD OF COMBUSTION OF LOW-VALUE GAS, AND HIGH-STOVE EQUIPMENT
CN116144853A (zh) * 2022-11-29 2023-05-23 湖南华菱湘潭钢铁有限公司 一种快速恢复高炉炉况的方法
CN116200560A (zh) * 2021-11-30 2023-06-02 宝山钢铁股份有限公司 基于碳循环的高炉低碳炼铁方法

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4381938A (en) * 1980-06-12 1983-05-03 Claflin H Bruce Multi-purpose zone controlled blast furnace and method of producing hot metal, gases and slags
US5234490A (en) * 1991-11-29 1993-08-10 Armco Inc. Operating a blast furnace using dried top gas

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR721515A (fr) * 1930-07-23 1932-03-04 Tuyère à action alternante pour cubilots
GB872062A (en) * 1957-12-26 1961-07-05 Texaco Development Corp Ore reduction process and apparatus

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3904398A (en) * 1972-08-22 1975-09-09 Centre Rech Metallurgique Manufacturing pig iron in a blast furnace
US3955963A (en) * 1973-05-18 1976-05-11 Centre De Recherches Metallurgigues-Centrum Voor Research In De Metallurgie Method of reducing ore
US4047935A (en) * 1974-12-11 1977-09-13 United States Steel Corporation Process for direct-reduction of iron-ore employing nuclear reactor-powdered catalytic reformer
US20080237944A1 (en) * 2005-11-09 2008-10-02 Thyssenkrupp At.Protec Gmbh Method For Operating a Shaft Furnace, and Shaft Furnance Operable By That Method
US8173064B2 (en) 2005-11-09 2012-05-08 Thyssenkrupp At.Pro Tec Gmbh Method for operating a shaft furnace, and shaft furnance operable by that method
US8444910B2 (en) 2005-11-09 2013-05-21 Thyssenkrupp At.Pro Tec Gmbh Method for operating a shaft furnace, and shaft furnace operable by that method
EP2426223A4 (en) * 2009-04-30 2015-03-18 Jfe Steel Corp PROCESS FOR USING A HIGH-STOVE, ASSOCIATED METHOD OF COMBUSTION OF LOW-VALUE GAS, AND HIGH-STOVE EQUIPMENT
CN116200560A (zh) * 2021-11-30 2023-06-02 宝山钢铁股份有限公司 基于碳循环的高炉低碳炼铁方法
CN116144853A (zh) * 2022-11-29 2023-05-23 湖南华菱湘潭钢铁有限公司 一种快速恢复高炉炉况的方法

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Publication number Publication date
LU63311A1 (enExample) 1971-09-13
NL7107044A (enExample) 1971-12-22
BE767715A (nl) 1971-10-18
IT940424B (it) 1973-02-10
AT325075B (de) 1975-10-10
FR2095390B1 (enExample) 1974-04-26
NL157056B (nl) 1978-06-15
GB1334174A (en) 1973-10-17
DE2030468B2 (de) 1975-07-24
FR2095390A1 (enExample) 1972-02-11
DE2030468A1 (de) 1972-01-05

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