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
  • C21C5/48—Bottoms or tuyéres of converters

Definitions

• the present invention relates to tuyeres of refining converters with separate, double or multiple feed, blowing an oxidizing gas, which may be pure oxygen, in the central conduit of the tuyere, while the peripheral annular conduit is fed by a substance protecting the nose of the tuyere against hot wear.
• an oxidizing gas which may be pure oxygen
• the present invention has as its object a process for protection of a tuyere of a refining converter with separate, double or multiple feed, blowing an oxidizing gas which may be pure oxygen through one of its conduits, which may be the central conduit, characterised by the feed of at least one other conduit of the tuyere, which may be the peripheral conduit or conduits, with a viscous, pasty, or powdery material, which is compressed, and which contain carbon, and more particularly heavy hydrocarbons, and protects the nose of the tuyere against hot wear.
• the material which protects the tuyere against hot wear is a paste constituted by dissolution of a suitable proportion of paraffin in fuel oil.
• the material which protects the tuyere against hot wear is constituted by residues from the treatment of crude mineral oils, such as semi-fluid pitches, or soft pitches, or hard pitches, or heavy or extra heavy fuel oil, or greases.
• the material which protects the nose of the tuyere is constituted by coke in fine pieces, or pulverised and compressed.
• the material which protects the nose of the tuyere is constituted by pulverised carbon in suspension in a fluid or pasty material.
• the material which protects the nose of the tuyere is a dissolution in a suitable proportion of pitch or petroleum coke in fuel oil.
• the material which protects the nose of the tuyere is a tar.
• the material which protects the nose of the tuyere is a more or less pasty filling of tar and ofa refractory lining material in small fragments or in grains, which may be dolomite or magnesia or chalk, or any other suitable refractory material.
• the flow of protective viscous, pasty or powdery material is controlled by any suitable mechanical, electrical or pneumatic means, such that it may be increased if appreciable wear of the tuyere appears and reduced if a partial obstruction of the tuyere is produced, deleteriously reducing the flow of oxidizing gas.
• the protection of the tuyere with separate, triple or multiple feed is improved by the introduction of a third fluid, such as ordinary air, or a neutral gas, or steam, or water, for example, into an intermediate conduit between the central conduit of the tuyere blowing pure oxygen or an oxidizing gas and the peripheral conduit or conduits fed by the protective, viscous or pasty or powdery material, under pressure.
• a third fluid such as ordinary air, or a neutral gas, or steam, or water
• This variant of the invention has the effect of opposing any partial obstruction of the central conduit of the tuyere which may be produced when certain viscous or pasty materials are employed.
• one of the main advantages of the invention as compared with known processes, is that'it does not use a liquid or gaseous fluid for the protection of the tuyere, but a substance of a consistency which is intermediate between the purely liquid state and the purely solid state, and which nevertheless is able to flow, i.e., a viscous, pasty or powdery substance, which is compressed; the compression ensures its advance into the tuyere to the extent of its consumption at the nose of the latter.
• a tuyere constituted by two concentric tubes, the inner tube having an inner diameter of 20 mm and an outer diameter of 25 mm, the outer tube having an inner diameter of 30 mm and an outer diameter of 35 mm, the two tubes being precisely centred one within the other in a conventional manner, pure oxygen is blown into the inner tube, at the rate of 25Nm /min at 12 bars, and crude vaseline is introduced into the outer tube at the rate of 1 kg per minute, by means of a greaser of conventional type, suitably regulated for the duration of at least one operation of refining in the converter. For a blow of 10 minutes, the consumption of vaseline per tuyere is thus 10 kg per operation.
• the total consumption of vaseline is kg, i.e., about 2.5 Kg to the tonne of steel produced.
• Process for the protection of a tuyere of a refining converter with multiple feed the steps of blowing an oxidizing gas including pure oxygen, through one of its conduits, which may be the central conduit of the tuyere, and feeding at least one peripheral conduit of the tuyere with a carbon containing material selected from the group consisting of viscous hydrocarbons, pasty hydrocarbons and compressed powders containing carbon whereby the nose of the tuyere is protected against wear by hot corrosion.
• the carbon containing material being residues from the treatment of crude mineral oils selected from the group consisting of semi-fluid pitches, soft pitches, hard pitches, heavy fuel oil, extra heavy fuel oil and greases.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)
• Loading And Unloading Of Fuel Tanks Or Ships (AREA)
• Carbon Steel Or Casting Steel Manufacturing (AREA)
• Furnace Charging Or Discharging (AREA)
• Production Of Liquid Hydrocarbon Mixture For Refining Petroleum (AREA)

Applications Claiming Priority (1)

Publications (1)

Family

ID=9083236

Family Applications (1)

Country Status (13)

Cited By (2)

Families Citing this family (3)

Citations (1)

• 0
  • BE BE788512D patent/BE788512A/xx unknown
• 1971
  • 1971-09-21 FR FR7133852A patent/FR2153153B1/fr not_active Expired
• 1972
  • 1972-08-11 GB GB3760572A patent/GB1398726A/en not_active Expired
  • 1972-09-06 ZA ZA726088A patent/ZA726088B/xx unknown
  • 1972-09-07 US US00286936A patent/US3801084A/en not_active Expired - Lifetime
  • 1972-09-11 CA CA151,435A patent/CA999139A/fr not_active Expired
  • 1972-09-14 IT IT69915/72A patent/IT974966B/it active
  • 1972-09-19 BR BR006472/72A patent/BR7206472D0/pt unknown
  • 1972-09-19 PL PL1972157812A patent/PL76129B1/pl unknown
  • 1972-09-19 LU LU66112A patent/LU66112A1/xx unknown
  • 1972-09-20 SU SU1834318A patent/SU453848A3/ru active
  • 1972-09-20 ES ES406860A patent/ES406860A1/es not_active Expired
  • 1972-09-21 JP JP47095058A patent/JPS5241722B2/ja not_active Expired

Patent Citations (1)

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