Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
  • B22D1/002—Treatment with gases
  • B22D1/005—Injection assemblies therefor
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D1/00—Treatment of fused masses in the ladle or the supply runners before casting
• • 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
  • F27D3/00—Charging; Discharging; Manipulation of charge
  • F27D3/16—Introducing a fluid jet or current into the charge

Definitions

• the present invention is concerned with the delivery of ⁇ 5 a pressurized gas to a molten metal bath contained in a container, for the purpose of purging and/or agitating the molten metal, in accordance with the preamble of Claim 1, and relates to a method of clearing the throughflow passage of a gas-delivery nozzle from the 10 solid metal blockages that are liable to occur when the delivery of gas to the melt is stopped.
• the invention also relates to an arrangement according to the preamble of Claim 2 for carrying out the inventive method.
• Ladles are used to transport and to treat molten metals in the steel, metal and ferroalloying industries.
• an inert gas such as argon, is injected into the melt through the bottom of the ladle. Hitherto, this gas has
• the molten material is unable to penetrate the pores or channels.
• porous plugs place a limit on the gas- pressures that can be used, which in turn places a limit
• the object of the present invention is to eliminate the aforesaid problems encountered with the use of nozzles for injecting gases into ladles, so as to enable the porous plugs used hitherto to be replaced with nozzles.
• the inventive nozzle may, for example, be mounted on the bottom of a molten metal container, such as a ladle, converter or the like.
• the nozzle is connected to a container which contains gas under high pressure, through the intermediary of a valve which functions to « control the gas flow and gas pressure.
• the nozzle or a part of the nozzle, is comprised of an electrically conductive material of such electrical resistance as to generate heat when an electric current is passed therethrough.
• the nozzle includes a heating wire which is connected to a source of electric current and which is wound around the nozzle tube or around the region of the gas throughflow passage, said
• tube preferably being made of a ceramic material.
• Pro ⁇ vided on the bottom end of the nozzle is a screw-thread ⁇ ed tube for connection with a quick-coupling between the nozzle and the conduit or pipe leading to the gas-flow control valve.
• the nozzle is surrounded by a body of
• the valve of the gas container is opened to allow gas to pass from the container while, at the same time causing an electric current to be applied to the nozzle, such as to heat at the nozzle and therewith
• 2 orifice is suitably from 0.2 to 15mm , preferably from
• the gas pressure will suitably lie in a range of from 5 to 250 bars, preferably from 10 to 50 bars. It will be understand from the aforegoing that when using nozzles to deliver a purging gas to molten metal contained in a ladle, the nozzle will become blocked by the molten metal which is drawn into the nozzle immedi- ately the supply of gas is cut-off, by closing the gas- flow control valve, this molten metal freezing on the nozzle walls and forming a solid plug. In accordance with the invention, when the valve is opened to allow pressurized gas to flow from the gas container an elec- trie current is, at the same time, supplied to the nozzle, which subsequently becomes hot enough to melt or at least partially melt the plug.
• the force of the gas entering the nozzle is then suffi ⁇ cient to push the plug from the nozzle and into the molten metal bath.
• the gas pressure and gas flow can then be adjusted to values appropriate to gas-purging purposes and also to the geometry of the container, i.e. the ladle or converter.
• the arrangement also includes a monitoring means which monitors the state of gas throughflow and which func ⁇ tions to switch off the supply of electric current to the nozzle when gas flows freely therethrough

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Furnace Charging Or Discharging (AREA)
• Treatment Of Steel In Its Molten State (AREA)
• Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
• Manufacture And Refinement Of Metals (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=20382038

Family Applications (1)

Country Status (4)

Family Cites Families (3)

• 1991
  • 1991-03-04 SE SE9100616A patent/SE470009B/sv not_active IP Right Cessation
• 1992
  • 1992-02-20 AU AU13502/92A patent/AU1350292A/en not_active Abandoned
  • 1992-02-20 WO PCT/SE1992/000103 patent/WO1992015413A1/en not_active Application Discontinuation
  • 1992-02-20 EP EP19920906195 patent/EP0574479A1/en not_active Withdrawn

Non-Patent Citations (1)

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