US3559623A - Lance for blowing oxygen into a kaldo furnace - Google Patents

Lance for blowing oxygen into a kaldo furnace Download PDF

Info

Publication number
US3559623A
US3559623A US792416*A US3559623DA US3559623A US 3559623 A US3559623 A US 3559623A US 3559623D A US3559623D A US 3559623DA US 3559623 A US3559623 A US 3559623A
Authority
US
United States
Prior art keywords
duct
lance
oxygen
main duct
auxiliary
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 - Lifetime
Application number
US792416*A
Other languages
English (en)
Inventor
Georges Decamps
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.)
Sollac SA
Original Assignee
Lorraine de Laminage Continu SA SOLLAC
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 Lorraine de Laminage Continu SA SOLLAC filed Critical Lorraine de Laminage Continu SA SOLLAC
Application granted granted Critical
Publication of US3559623A publication Critical patent/US3559623A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
    • C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
    • C21C5/28—Manufacture of steel in the converter
    • C21C5/42—Constructional features of converters
    • C21C5/46—Details or accessories
    • C21C5/4606—Lances or injectors

Definitions

  • the auxiliary duct means debouch substantially tangentially into the main oxygen duct at a point spaced from the outlet orifice of the lance by a distance which is at least four times the mean diameter of the portion of the main duct between the outlet orifice and the auxiliary oxygen duct means.
  • This invention relates to a lance for blowing oxygen into a furnace for refining iron into steel by the Kaldo process.
  • molten iron is contained in a furnace which is rapidly rotated about its longitudinal axis and which is inclined at an angle, generally about l620, to the horizontal.
  • the furnace has an opening at one end through which a lance directs oxygen on to the slag-metal surface.
  • the lance is inclined at an angle, generally about 20 to about 30, to the horizontal.
  • the lance is provided with a separate motor to enable it to be given a sweeping or oscillating motion in relation to the slag-metal surface when desired.
  • the oxygen is delivered by the lance at a linear flow rate such that one portion of the oxygen penetrates into the slag-metal bath and serves, more particularly, for the combustion of carbon to form carbon monoxide, and another portion of the oxygen remains in the free space of the furnace and is used in the combustion of the carbon monoxide issuing from the bath into carbon dioxide.
  • the combustion of the carbon monoxide which takes place in the furnace itself, improves the thermal economy of the refining operation and permits the melting of a considerable quantity of iron.
  • the volume flow rate of oxygen determines the linear flow rate of this .gas on impact with the slag-metal bath.
  • the desirability of obtaining an optimum combustion'coefficient for the conversion of carbon monoxide into carbon dioxide determines the distribution coefficient which is required between the portion of oxygen penetrating the slag-metal bath and the portion of oxygen remaining in the free space of the furnace and, therefore, determines the specific linear flow rate of the oxygen on impact with the slag-metal surface, which in turn fixes the volume flow rate of oxygen.
  • a lance for blowing oxygen into a furnace of the Kaldo-type comprising a main duct, a plurality of auxiliary duct means and a cooling circuit
  • the main duct comprises a rearward section which is connectable to a source of oxygen, a forward section which has an outlet orifice and is of a length which is at least 4 times its mean diameter, and a mixing chamber which is disposed between and interconnects said rearward and forward sections;
  • the plurality of auxiliary duct means are disposed externally of the rearward section of said main duct and debouch substantially tangentially into the mixing chamber; and wherein the cooling circuit encases the forward section and mixing chamber of said main duct and the plurality of auxiliary duct means.
  • the plurality of auxiliary duct means comprise a plurality of ducts arranged in the form of a helix about the rearward section of the main duct.
  • the mixing chamber of the main duct it is preferred for the mixing chamber of the main duct to have an axial length which is at least equal to the radial width of the helical ducts.
  • a lance according to the invention comprises a central tube, which has a rearward section, a mixing chamber and a forward section, defining the main oxygen duct, and a coaxial tube constituting with the external wall of the rearward section of 'the central tube an auxiliary oxygen duct of annular form which debouches, through a plurality of helical ducts into the mixing chamber.
  • These tubes are placed in a cylindrical double-wall casing, which constitutes with the coaxial tube and the forward section of the main tube the cooling circuit.
  • the forward section of the main tube has a length equal to at least 4 times its mean diameter.
  • the forward section is made fast at its rear end with the coaxial tube by means of a cylindrical connecting sleeve forming part of the coaxial tube.
  • the plurality of helical ducts extend over the entire cross section of the annular space defined between the coaxial tube and the rearward section of the central tube and debouch tangentially into the mixing chamber and thence into the forward section of the central tube, the mixing chamber having a diameter which is equal to that of the coaxial tube and an axial length which is at least equal to the radial width of said helical ducts.
  • all the oxygen entering through the rearward section of the main duct into the mixing chamber is rotated by the tangential jets of oxygen issuing from the auxiliary ducts, and the total quantity of oxygen issuing from the mixing chamber undergoes, in the forward section of the main duct, a sufficient pressure loss so that at the outlet orifice of the lance the jet of oxygen in its entirety flares rapidly in the form of a cone substantially without any central stabbing dart portion remaining.
  • FIG. 1 shows a diagrammatic axial section of a lance according to the invention.
  • FIG. 2 is a diagrammatic axial section of an enlarged scale of part of the lance shown in FIG. I.
  • the lance comprises a double-walled outer casing 1, a central tube 4 and a tube 7 disposed between and coaxial with the outer casing l and the central tube 4.
  • the double-walled outer casing 1 constitutes a cooling circuit connectable at 2 to a source of cooling fluid and at 3 to a recovery tank therefor, these not being shown.
  • the central tube 4 constitutes the main oxygen duct which is connectable at its rear end 5 to a source of oxygen under pressure and which debouches into the free atmosphere at its fore end 6.
  • the coaxial tube 7 and an extension sleeve 10 (FIG.
  • the central tube 4 can be considered to consist of two sections 4a and 4b separated by a mixing chamber 15.
  • the forward section 40 extends from the point at which the annular passageway 8 debouches into the central tube 4 to the outlet of the central tube 4.
  • the forward section 4a has a length which is substantially greater than its diameter, being equal to at least 4 and preferably from 5 to 10 times its diameter.
  • the forward section 40 of the tube 4 is fixed to the main portion of the tube 7 by means of the extension sleeve 10 which includes an annular shoulder 11 whose internal diameter is equal to that of the forward section 4a of the tube 4 and whose external diameter is equal to that of the main portion of the tube 7.
  • the rearward section 4b of the tube 4 extends from the point at which the annular passageway 8 debouches into the central tube 4 rearwardly to the point at which the tube 4 can be connected to the source of oxygen under pressure.
  • the rearward section 4!: of the tube 4 is provided on the outside thereof with helical ducts 12 which are defined by grooves 13 of a screw-threaded sleeve 14 and by the internal wall of the connecting sleeve 10.
  • the helical ducts 12 extend substantially over the entire cross section of the annular passageway 8 between the connecting sleeve and the external wall of the rearward section 4b of the tube 4. At one end, the helical ducts 12 communicate with the annular passageway 8, that is to say with the secondary oxygen duct and, at the other end, the helical ducts 12 deboueh into the mixing chamber 15, which is bounded by the shoulder 11, a portion of the connecting sleeve 10 and the frontal wall of the screw-threaded sleeve 14. and thence into the forward section 4a of the tube 4.
  • the chamber 15 communicates, on the one hand, with the rearward section 4b of the central tube 4 and, on the other hand, with the forward section 40 through an aperture 16 bounded by the inside of the shoulder 11.
  • the mixing chamber 15 has a diameter equal to the internal diameter of the tube 7 and of the connecting sleeve 10 and has an axial length at least equal to the radial width of the helical ducts 12.
  • the tube 4 had a diameter of 162 mm. and the mixing chamber 15 was situated at 1,300 mm. from the outlet orifice of the lance. With this lance it was possible to achieve a volume flow rate of oxygen of 560 NmP/mn.
  • V linear flow rates of oxygen on impact
  • D theoretical distances
  • a of the lance relative to the horizontal employing a volume flow rate of oxygen of 560 Nmflmn.
  • the jet of oxygen issuing from the lance is more or less flared in conical form depending on the magnitude of the oxygen delivery coming from the auxiliary oxygen ducts and mixing with the quantity of oxygen of the main oxygen duct.
  • the length of the forward section of the main duct is at least equal to 4 times the mean diameter of said duct, since it is in this section that a considerable pressure loss occurs on the part of the oxygen flow whose flow turbulence has just been substantially increased in the mixing chamber by the tangential jets issuing from the auxiliary ducts.
  • the pressure of the jet on issuing from the lance is relatively low.
  • a lance for blowing oxygen into a furnace of the Kaldotype ad comprising a main oxygen duct, a plurality of auxiliary oxygen duct means and a cooling circuit
  • the main duct comprises a rearward section which is connectable to a source of oxygen, a forward section which has the same diameter as the rearward section and an outlet orifice, and is of a length which is at least 4 times its mean diameter, and a mixing chamber which is disposed between and interconnects said rearward and forward sections and flushes on the one side with the forward end of the rearward section and on the other side with the rearward end of the forward section;
  • the plurality of auxiliary duct means are disposed externally of the rearward section of said main duct and deboueh substantially tangentially into the mixing chamber; and wherein the cooling circuit encases the forward section and mixing chamber of said main duct and the plurality of auxiliary duct means.
  • a lance for blowing oxygen into a furnace of the Kaldotype comprising a main duct, a plurality of auxiliary duct means and a cooling circuit
  • the main duct comprises a rearward section which is connectable to a source of oxygen, a forward section which has an outlet orifice and is of a length which is at least 4 times its mean diameter, and a mixing chamber which is disposed between and interconnects said rearward and forward sections and which has an axial length which is at least equal to the radial width of the auxiliary duct means
  • the plurality of auxiliary duct means comprises a plurality of ducts arranged helically about the rearward section of the main duct and deboueh substantially tangentially into the mixing chamber
  • the cooling circuit encases the forward section and mixing chamber of said main duct and the plurality of auxiliary duct means.

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)
  • Physical Or Chemical Processes And Apparatus (AREA)
  • Carbon Steel Or Casting Steel Manufacturing (AREA)
US792416*A 1968-01-25 1969-01-21 Lance for blowing oxygen into a kaldo furnace Expired - Lifetime US3559623A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR137485 1968-01-25

Publications (1)

Publication Number Publication Date
US3559623A true US3559623A (en) 1971-02-02

Family

ID=8645119

Family Applications (1)

Application Number Title Priority Date Filing Date
US792416*A Expired - Lifetime US3559623A (en) 1968-01-25 1969-01-21 Lance for blowing oxygen into a kaldo furnace

Country Status (6)

Country Link
US (1) US3559623A (en))
BE (1) BE725942A (en))
DE (1) DE1902637B2 (en))
FR (1) FR1564580A (en))
GB (1) GB1235657A (en))
LU (1) LU57675A1 (en))

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3910209A (en) * 1973-11-12 1975-10-07 Rheinstahl Ag Fluidized bed furnace having fuel air supply lance and a fuel air supply lance construction
US4320668A (en) * 1979-03-28 1982-03-23 Nippon Kokan Kabushiki Kaisha Sub-lance assembly for sampling and temperature-measuring of molten metal during refining thereof
US5596149A (en) * 1995-10-23 1997-01-21 The Babcock & Wilcox Company Pressure measurement tap for a pressurized fluidized bed

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2540519A2 (fr) * 1980-08-26 1984-08-10 Ugine Aciers Buse d'injection d'oxygene a jet supersonique stabilise pour la decarburation des fontes et, en particulier, des fontes au chrome
JPS59145717A (ja) * 1983-02-04 1984-08-21 ユジンヌ・アシエ 鋳鉄，特にクロム鋳鉄を脱炭するための安定した超音速流を噴出する酸素噴射ノズル
LU87856A1 (fr) * 1990-12-10 1992-08-25 Arbed Lance de soufflage
AUPQ535500A0 (en) * 2000-01-31 2000-02-17 Technological Resources Pty Limited Apparatus for injecting gas into a vessel

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3112194A (en) * 1960-10-19 1963-11-26 Union Carbide Corp Molten bath treating method and apparatus
US3169161A (en) * 1961-04-05 1965-02-09 Air Prod & Chem Oxygen-fuel probe
US3321139A (en) * 1963-11-25 1967-05-23 Siderurgie Fse Inst Rech Apparatus for treating molten metals

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3112194A (en) * 1960-10-19 1963-11-26 Union Carbide Corp Molten bath treating method and apparatus
US3169161A (en) * 1961-04-05 1965-02-09 Air Prod & Chem Oxygen-fuel probe
US3321139A (en) * 1963-11-25 1967-05-23 Siderurgie Fse Inst Rech Apparatus for treating molten metals

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3910209A (en) * 1973-11-12 1975-10-07 Rheinstahl Ag Fluidized bed furnace having fuel air supply lance and a fuel air supply lance construction
US4320668A (en) * 1979-03-28 1982-03-23 Nippon Kokan Kabushiki Kaisha Sub-lance assembly for sampling and temperature-measuring of molten metal during refining thereof
US5596149A (en) * 1995-10-23 1997-01-21 The Babcock & Wilcox Company Pressure measurement tap for a pressurized fluidized bed

Also Published As

Publication number Publication date
DE1902637C3 (en)) 1973-10-11
DE1902637A1 (de) 1971-04-22
DE1902637B2 (de) 1973-03-15
FR1564580A (en)) 1969-04-25
GB1235657A (en) 1971-06-16
BE725942A (en)) 1969-05-29
LU57675A1 (en)) 1969-04-15

Similar Documents

Publication Publication Date Title
US3559623A (en) Lance for blowing oxygen into a kaldo furnace
US3567202A (en) Device for injection by top-blowing into a metal bath
AU2007246207B2 (en) Apparatus for injecting gas into a vessel
US2499207A (en) Pressure-type burner and method of burning fuel
US2101850A (en) Muzzle attachment for guns
ES8405138A1 (es) Un procedimiento para inyectar un combustible pulverizado, en un alto horno.
US3612737A (en) Turbulence muffle burner
US3112194A (en) Molten bath treating method and apparatus
US3201104A (en) Oxygen lance for subsurface use
US3310238A (en) Furnace lances
KR930703466A (ko) 송풍파이프 및 송풍구장치
FR2451945A1 (fr) Tuyere de brassage de bain de metal liquide
US3938743A (en) Adjustably positionable supersonic nozzle means
JP2786266B2 (ja) 酸素吹き込みランス
EP0151499A2 (en) Liquid-cooled lance for blowing oxygen onto a steel bath and method of operating the lance
JP2005060834A (ja) 冶金用微粉炭吹き込みバーナー及び冶金炉内への微粉炭吹き込み方法
US3957258A (en) Nozzles of the lance heads for blowing oxygen from above in the refining processes
JP4427469B2 (ja) 高炉微粉炭吹込み用バーナー及びこれを用いた微粉炭吹込み方法
US2421552A (en) Casing and nozzle construction for rocket motors
US3309195A (en) Method of delivering oxygen to basic oxygen furnaces, and oxygen lances therefor
SU501073A1 (ru) Топливо-кислородна фурма
RU2181384C1 (ru) Фурма для продувки расплава металла
SU287990A1 (ru) Фурма
US2717031A (en) Injector operated welding and cutting burner
SU138686A1 (ru) Газова горелка