CA1176059A - Process for protection of nozzles and refractory lining of a vessel for refining molten metal - Google Patents

Process for protection of nozzles and refractory lining of a vessel for refining molten metal

Info

Publication number
CA1176059A
CA1176059A CA000391551A CA391551A CA1176059A CA 1176059 A CA1176059 A CA 1176059A CA 000391551 A CA000391551 A CA 000391551A CA 391551 A CA391551 A CA 391551A CA 1176059 A CA1176059 A CA 1176059A
Authority
CA
Canada
Prior art keywords
process according
hydroxyl compound
gas
pipe
molten metal
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.)
Expired
Application number
CA000391551A
Other languages
French (fr)
Inventor
Dalton Nose
William Wells
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.)
Korf Technologies Inc
Original Assignee
Korf Technologies Inc
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 Korf Technologies Inc filed Critical Korf Technologies Inc
Application granted granted Critical
Publication of CA1176059A publication Critical patent/CA1176059A/en
Expired legal-status Critical Current

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/52Manufacture of steel in electric furnaces
    • C21C5/5211Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace
    • C21C5/5217Manufacture of steel in electric furnaces in an alternating current [AC] electric arc furnace equipped with burners or devices for injecting gas, i.e. oxygen, or pulverulent materials into the furnace
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/04Manufacture of hearth-furnace steel, e.g. Siemens-Martin steel
    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21CPROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28Manufacture of steel in the converter
    • C21C5/42Constructional features of converters
    • C21C5/46Details or accessories
    • C21C5/48Bottoms or tuyéres of converters
    • YGENERAL 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
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00Technologies related to metal processing
    • Y02P10/20Recycling

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Furnace Charging Or Discharging (AREA)
  • Nozzles (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
  • Furnace Housings, Linings, Walls, And Ceilings (AREA)
  • Furnace Details (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Abstract

ABSTRACT
A process for protecting oxygen injection nozzles and the surrounding refractory lining of a molten metal refining vessel having such oxygen injection nozzles beneath the bath surface.
The injection nozzle comprises at least three concentric pipes, the central conduit thereof being connected to a source of oxygen, the outer annular conduits thereof each being supplied with a protective fluid, said protective fluid containing at least one hydroxyl compound or water or a mixture thereof. The protective hydroxyl compounds are selected from the gaseous or liquid alcohol group and preferably from the aliphatic alcohol group. Methanol, ethanol, propanol and butanol are preferred alcohols.
Apparatus for carrying out the process is also disclosed.

Description

~17~S9 This ii~vent ion relates to a method ~or reiinir.g molten met~l:l, arl(~ more particu].arly to t~le refining of iron to steel.
Whell refining molten metal, particularly liquid pig iron, in an open hearth furnace, an electric arc furnace or in a converter by introducing an oxygen-containing gas into the molten metal below the surface of the bath, there is a problem involving the protection of the nozzle and the refractory lining of the vessel surrounding the nozzle fromtoo rapid wear.
In general, gaseous or liquid hydrocarbon compounds are used as a.protective fluid for this purpose.
OBJECT OF THE INVENTION
The principal object of the invention is to reduce the nozzle and refractory lining consumption in a process for refining molten metal, thus attaining a longer service li.fe of the device for injection of the oxygen-containing gas~

..~ ,...
SUMMARY OF INV~NTION
The present invention is a process for protecting oxygen injection nozzles and the surrounding refractory lining of a molten metal :refining vessel having such oxygen injection nozzles beneath the bat}l surface. The injection nozzle comprises at least three concentric pipes, the central conduit thereof being connected to a source of o~ygen, the outer annular conduits thereof each being supplied with a protective fluid, said protective fluid containing at east one of the group comprising a hydroxyl compound, water and a mixture thereof. The protective fluids can be the same in each annular passageway or they can be different compounds or mixtures.

sd/' ~lr ~176~59 It has become possible through the process of the invention to attain a service life of the nozzles and the refractory lining surrounding the nozzles of 400 operating hours. The extended service life of the nozzles compared to that in known processes is attributed to the increased heat of dissociation of hydroxyl compounds compared to hydrocarbon compounds. It has been deter-mined that 0.38 kg of alcohol exhibits the same heat of dissocia-tion when used for local cooling as 1 kg of propane (C3H8). It is also possible to blend the hydroxyl compounds with water or to use only water for cooling. Water must be atomized or vaporized to be effective.
Particularly suitable hydroxyl compounds are liquid ones that are miscible with water and remove as much heat as possible from the surroundings through an endothermic dissociation reaction.
Monovalent or polyvalent aliphatic or aromatic alcohols are particularly suitable for this purpose.
DESCRIPTION OF THE DRAWINGS
-The present invention will be more readily understood by referring to the following detailed description and the appended drawings, in which Figure 1 is a sectional view of an injection device according to the invention in a hearth-type furnace.
Figure 2 is an enlarged sectional view of a portion of Figure 1 showing the injection device with greater clarity.
DETAILED DESCRIPTION
Referring now to Figure 1, a hearth-type furnace 1 such as an open hearth furnace, has an injection device 2 installed in the sidewall thereof at at least one location, the device opening into the vessel under the bath level 3. Two burners 4 are directed downwardly toward the bath above the bath level.
Docket 1082
-2- Wells Nose 6(~59 As can be seen in Figure 2, the injection nozzle consists of three concentric pipes 11, 12, 13 held apart by spacers (not shown3, each of which is provided with a respective gas inlet 14, 15, 16 for gases or gas mixtures. These pipes form a central S conduit 17 and a first annular conduit 18 and a second annular, conduit 19. The opening of the pipes into the furnace interior can, as depicted, be designed in the form of annular conduits but also with annular discs covering the annular conduits with outlet openings along the circumference. The outer pipe 13 is anchored in the brickwork 6. In the outer region of the furnace wall, outer pipe 13 is surrounded by a closed pipe section 20 having an inlet 21 for a gaseous medium to maintain a positive pressure within chamber 22. Two concentric discs 23 are mounted on the outer surface of this pipe section 20. The pipe section 20, including the associated discs 23, serves to prevent the combustible gases flowing back between the refractory material and the outer jacket pipe. Pipe section 20 is optional.
Alternatively, discs 23 may be mounted on the outer jacket pipe 13.
Oxygen is injected during the refining process through the central conduit 17. Alcohol is supplied through the first annular conduit 18, which changes to a gaseous state at the tip of the nozzle because of the temperatures prevailing there. A mixture of 50% alconol and 50% carbon dioxide is injected through the second annular conduit 19. Nitrogen is supplied to the pipe section 20 through inlet 21.
The following indicates the process conditions for a preferred embodiment.
Docket 1082
-3- ~'ells ~ose ~76~S9 The concentrically arranged pipes of the injection device have the following dimensions:
Inner pipe 11 Inner Diameter 13 mm Outer Diameter 16 mm First jacket pipe 12 Inner Diameter 20 mm Outer Diameter 26 mm Second jacket pipe 13 Inner Diameter 32 mm Outer Diameter 48 mm Pipe section 20 Inner Diameter 60 mm Outer Diameter 72 mm Concentric discs 23 Outer Diameter 150 mm Pressure and throughput of the gases/gas mixtures measured in the supply lines to the individual pipes 11, 12, 13:
Pipe 11 and central conduit 17: 3.5 bar 3 m3/min First jacket pipe 12 and first annular conduit 18: 2.5 bar 0.3 m3/min Second jacket pipe 13 and second annular conduit 19: 2.5 bar 0.3 m3/min The values indicated apply to a 25 ton open hearth furnace.
The indicated gas pressure values increase by about 0.5 to 1 bar for larger furnaces and with application of the injection device in a converter.
If a mixture of alcohol and water is supplied through the first conduit instead of alcohol alone, the pressure is increased as well. A pressure of 3.5 bar has shown itself to be suitable with a mixture of 60% alcohol and 40% water.

Docket 1082
4- IYells Nose ~76~59 Table I shows the acceptable broad ranges of fluid pressures and flow rates through the three gas passageways.
Table I
Conduit Fluid Pressure (Bar) Flow (Nm3/min) 17 Oxygen 2.5 to 4.5 2.0 to 5.0 18,19 Carrier Gas 2.0 to 3.5 0.2 to 0.6 Protective Fluid 4.0 to 6.0 0.3 to 0.7 l/min Table II shows the preferred ranges of fluid pressures and flow rates through the three gas conduits.
Table II
Conduit Fluid Pressure (Bar) Flow (Nm3/min) 17 Oxygen 3.0 to 4.0 3.0 to 4.0 18,19 Carrier Gas 3.0 to 3.5 0.3 to 0.5 Protective Fluid 4.5 to 5.5 0.4 to 0.6 l/min The carrier gas in the examples of Tables I and II is preferably nitrogen. The gas indicated as oxygen can be any oxidizing gas or oxygen-containing gas.

Doc~et 1082 I~ells ~'ose

Claims (14)

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. Process for protection of underbath blowing nozzles and refractory lining of a vessel for refing a bath of molten metal therein, wherein an injection device projects through the vessel wall below the bath surface, said injection device being composed of at least three concentric pipes with annular gas passageways therebet-ween, said process comprising:
injecting oxygen through the central conduit of said device and injecting a protective fluid through the annu-lar passageways thereof, said protective fluid containing at least one of the group comprising an hydroxyl compound, water, and a blend of the two.
2. Process according to claim 1, characterized in that the hydroxyl compound is selected from the gaseous and liquid alcohol group.
3. Process according to claim 2, characterized in that the hydroxyl compound is selected from the aliphatic alcohol group.
4. Process according to claim 3, characterized in that the hydroxyl compound is selected from the methanol, ethanol, propanol and butanol group.
5. Process according to claim 1, characterized in that the blend of hydroxyl compounds and water contains at least 40% water by weight.
6. Process according to claim 1, characterized in that at least one hydroxyl compound is supplied through the inner annular passageway (18) and a blend of at least one hydroxyl compound and carbon dioxide is supplied through the outer annular passageway (19).
7. Process according to claim 1, characterized in that at least one hydroxyl compound is supplied through the inner annular passageway (18) and a blend of at least one hydroxyl compound and an inert gas is supplied through the outer annular passageway (19).
8. Process according to claim 6, characterized in that the proportion of the carbon dioxide is increased during the course of the refining process.
9. Process according to claim 1 wherein said protective fluid is water in atomized form.
10. Process according to claim 1 wherein said protective fluid is water in vaporized form.
11. Apparatus for injecting treating gas into a molten metal containing vessel beneath the surface of the molten metal therein, comprising:
a central pipe connected to a source of treating gas;
an annular jacketing pipe surrounding said central pipe and spaced therefrom to form an annular gas passageway therebetween, said jacketing pipe being connected to a source of protective gas;

an outer pipe surrounding said jacketing pipe and spaced therefrom to form an annular space therebetween, said outer pipe being connected to a source of protective gas; and a pair of spaced discs mounted external to and concentric with said outer pipe.
12. Apparatus according to claim 11 further comprising a tubular chamber surrounding said outer pipe.
13. Apparatus according to claim 12 wherein said discs are mounted on said chamber.
14. Apparatus according to claim 12 further comprising an inlet for a gaseous medium to maintain a positive pressure within said tubular chamber.
CA000391551A 1980-12-05 1981-12-04 Process for protection of nozzles and refractory lining of a vessel for refining molten metal Expired CA1176059A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19803045966 DE3045966A1 (en) 1980-12-05 1980-12-05 METHOD FOR PROTECTING THE NOZZLES AND THE FIRE-RESISTANT LINING OF A VESSEL TO FRESH A METAL MELT
DEP3045966.6 1980-12-05

Publications (1)

Publication Number Publication Date
CA1176059A true CA1176059A (en) 1984-10-16

Family

ID=6118446

Family Applications (1)

Application Number Title Priority Date Filing Date
CA000391551A Expired CA1176059A (en) 1980-12-05 1981-12-04 Process for protection of nozzles and refractory lining of a vessel for refining molten metal

Country Status (8)

Country Link
EP (2) EP0182965B1 (en)
BR (1) BR8108907A (en)
CA (1) CA1176059A (en)
DE (3) DE3045966A1 (en)
HU (1) HU193025B (en)
RO (1) RO85571B (en)
SU (1) SU1276262A3 (en)
WO (1) WO1982001891A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT394731B (en) * 1987-04-30 1992-06-10 Radex Austria Ag Method and gas-flushed block for blowing treatment materials into reaction vessels
US4754951A (en) * 1987-08-14 1988-07-05 Union Carbide Corporation Tuyere assembly and positioning method
DE4215858C2 (en) * 1992-05-14 1995-09-14 Metallgesellschaft Ag Method and device for the production of molten steel
DE4407769A1 (en) * 1994-03-09 1995-09-14 Metallgesellschaft Ag Method and device for producing molten steel from scrap
DE4429937A1 (en) * 1994-08-24 1996-02-29 Metallgesellschaft Ag Process for blowing non-ferrous metal scrap and metallurgical intermediates
AU5974396A (en) * 1995-06-07 1996-12-30 Molten Metal Technology, Inc. Appartus for self-sealing a submerged inlet tuyere of a molten metal reactor

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
BE635868A (en) * 1962-08-07
DE1758816C2 (en) * 1968-08-13 1975-11-20 Eisenwerk-Gesellschaft Maximilianshuette Mbh, 8458 Sulzbach-Rosenberg Process for refining pig iron to steel
DE1915133B1 (en) * 1969-03-25 1971-09-30 Noranda Mines Ltd Lance for introducing gases into molten material at high temperatures
FR2067143A1 (en) * 1969-11-13 1971-08-20 Creusot Loire Cooling upward-blowing immersed tuyere of refining converter
BE748186A (en) * 1970-03-27 1970-09-28 Centre Rech Metallurgique PNEUMATIC CAST IRON REFINING PROCESS.
BE781241A (en) * 1971-05-28 1972-07-17 Creusot Loire REFINING PROCESS FOR ALLIED STEELS CONTAINING CHROME AND MORE SPECIFICALLY STAINLESS STEELS
DE2147717A1 (en) * 1971-09-24 1973-03-29 Kloeckner Werke Ag Steel refining - using liquid coolant blown into melt together with oxygen through two-component blast-pipe
US3997334A (en) * 1972-04-28 1976-12-14 Centre De Recherches Metallurgiques-Centrum Voor Research In De Metallurgie Introduction of a liquid into a receptacle such as a converter
US3832161A (en) * 1972-07-18 1974-08-27 Creusot Loire Method of blowing-in through blast pipes submerged in a metallic bath
DE2326754C3 (en) * 1973-05-25 1978-04-20 Eisenwerk-Gesellschaft Maximilianshuette Mbh, 8458 Sulzbach-Rosenberg Device for the controlled supply of a fresh gas and a protective fluid medium
FR2340375A2 (en) * 1976-02-04 1977-09-02 Creusot Loire PROCESS FOR THE PREPARATION OF CHROME STEELS
US4023676A (en) * 1976-09-20 1977-05-17 Armco Steel Corporation Lance structure and method for oxygen refining of molten metal
DE2946030C2 (en) * 1979-11-14 1982-11-25 Korf Industrie Und Handel Gmbh + Co Kg, 7570 Baden-Baden Method for protecting the nozzles and the refractory lining of a vessel for refining a molten metal

Also Published As

Publication number Publication date
EP0182965A1 (en) 1986-06-04
BR8108907A (en) 1982-10-26
DE3045966A1 (en) 1982-07-08
DE3174854D1 (en) 1986-07-24
RO85571B (en) 1985-03-30
RO85571A (en) 1985-03-15
WO1982001891A1 (en) 1982-06-10
HU193025B (en) 1987-08-28
EP0182965B1 (en) 1988-12-21
DE3176955D1 (en) 1989-01-26
SU1276262A3 (en) 1986-12-07
EP0053802B1 (en) 1986-06-18
EP0053802A1 (en) 1982-06-16

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