Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D43/00—Mechanical cleaning, e.g. skimming of molten metals
  • B22D43/001—Retaining slag during pouring molten metal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
  • B22D11/10—Supplying or treating molten metal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/08—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like for bottom pouring
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/50—Pouring-nozzles
  • B22D41/507—Pouring-nozzles giving a rotating motion to the issuing molten metal
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B22—CASTING; POWDER METALLURGY
  • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
  • B22D41/00—Casting melt-holding vessels, e.g. ladles, tundishes, cups or the like
  • B22D41/50—Pouring-nozzles
  • B22D41/62—Pouring-nozzles with stirring or vibrating means
• • 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
  • C21C5/4653—Tapholes; Opening or plugging thereof

Definitions

• the present invention relates generally to vortex suppression in tundishes.
• a proposed method of vortex suppression of the invention uses a rotating magnetic field ("RMF") .
• RMF rotating magnetic field
• This method does not involve the arrangement of any ceramic components inside the tundish and therefore is free from the above-mentioned drawbacks.
• the parameters of RMF are easy to change and, hence, the process of vortex suppression using RMF can be easily controlled within broad limits.
• a method of suppressing a vortex arising in a tundish or ladle at the lowering .of the free surface of a melt below a critical level using a rotating magnetic field continuously excited by m- phase current (i.e., any suitable number of current phases or m-phase voltage) in the melt above an outflow pipe, wherein the direction of RMF rotation is opposite to the direction of melt rotation in the vortex.
• m- phase current i.e., any suitable number of current phases or m-phase voltage
• FIG. 1 shows a vertical cross-section of a portion of a tundish adjacent to a discharge hole with an RMF inductor, in accordance with the invention
• FIG. 2 shows a horizontal cross-section of a three-phase RMF inductor with six explicit poles, taken from line A-A of FIG. 1;
• FIG. 3 shows the configuration of pole pieces of a two-phase inductor with four explicit poles, in accordance with the invention
• FIG. 4 shows the configuration of pole pieces of a three-phase inductor with three explicit poles, in accordance with the invention
• FIG. 5 schematically illustrates induced current oscillations in the inductor windings, in accordance with the present invention
• FIG. 6 shows a schematic diagram of a tundish used during experiments on vortex suppression
• FIG. 7 shows the results of experiments conducted on the tundish of FIG. 6.
• a tundish cover 1 (FIG. 1) , inspection window 2 is made, and above this window 2, optical probe 3 may be mounted, which records the displacement of melt surface 4.
• m-phase voltage may be applied to inductor 6 (FIG. 2) .
• RMF is excited above discharge hole 5, which induces a rotating system of currents in the melt .
• Interaction of these currents with the RMF generates electromagnetic body forces (“EMBF”) that can either hinder or accelerate vortex formation above discharge hole 5, depending on the way of switching on inductor 6.
• EMBF electromagnetic body forces
• sinusoidal waveforms of current are generated in an inductor (e.g., inductor 6) of the type described herein such that RMF is excited above discharge hole 5.
• inductor 6 e.g., inductor 6
• superwaves may be generated and applied to inductor 6 when its windings are connected to a power supply (not shown) .
• FIG. 5 schematically illustrates the formation of doubly-modulated sinusoidal current oscillations (two-level SuperWaves) .
• FIG. 5 illustrates low-frequency carrier wave 110 modulated, for example, by waves 120 and 130. Minor waves 120 and 130 have progressively higher frequencies (compared to major wave 110) . Other modulation levels of even higher frequency may modulate major wave 110, but are not shown for clarity. This superwave is depicted in the time-domain in FIG. 5.
• the delay +t varied from 0 to 2 seconds, I 0 varied from 8A to 13A. Apparently, the greatest effect is observed at the maximal current in the absence of delay. It is noteworthy that in this case, maximal disturbance of the metal surface in the tundish is observed.
• the inductor may be made with 4 (items 7 in FIG. 3) , 8, etc. poles; in the case of three-phase current, the inductor may be made with 3 (items 8 in FIG. 4) , 6 (items 9 in FIG. 2) , etc. poles) .
• These poles may be located around the outflow pipe 10 (FIG. 1) .
• the magnetic circuit of inductor 6 preferably consists of ferromagnetic back 11 with explicit poles 9, 12 (FIG. 2) and coils 13 arranged on them (FIG. 1) .
• the magnetic circuit may preferably be made of sheet electrotechnical steel or in the form of thin-sheet jacket' 14 (FIG. 2) , preferably filled with iron powder 15 (FIG. 1) whose particles are electrically insulated.
• the magnetic circuit may preferably be cast from steel or cast iron.
• Pole pieces 16 (FIG. 1) , 7 (FIG. 3) , 8 (FIG.
• the inductor may preferably be fixed to tundish jacket 17 using flange 20, which may preferably be made of nonmagnetic steel rigidly connected with the poles of the magnetic circuit .

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Continuous Casting (AREA)
• Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (8)

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• 2005
  • 2005-09-13 WO PCT/US2005/032922 patent/WO2006031964A1/en active Application Filing
  • 2005-09-13 US US11/226,711 patent/US20060131795A1/en not_active Abandoned
  • 2005-09-13 BR BRPI0515178-3A patent/BRPI0515178A/pt not_active IP Right Cessation
  • 2005-09-13 CN CNA2005800347406A patent/CN101039768A/zh active Pending
  • 2005-09-13 CA CA002580166A patent/CA2580166A1/en not_active Abandoned
  • 2005-09-13 JP JP2007531477A patent/JP2008513214A/ja active Pending
  • 2005-09-13 KR KR1020077008110A patent/KR20070052343A/ko not_active Application Discontinuation
  • 2005-09-13 EP EP05795170A patent/EP1791665A1/en not_active Withdrawn

Non-Patent Citations (1)

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