EP0737531B1 - Elektromagnetisches Zurückhalten von Schmelze mittels Stromerregung - Google Patents

Elektromagnetisches Zurückhalten von Schmelze mittels Stromerregung Download PDF

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Publication number
EP0737531B1
EP0737531B1 EP19950105646 EP95105646A EP0737531B1 EP 0737531 B1 EP0737531 B1 EP 0737531B1 EP 19950105646 EP19950105646 EP 19950105646 EP 95105646 A EP95105646 A EP 95105646A EP 0737531 B1 EP0737531 B1 EP 0737531B1
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EP
European Patent Office
Prior art keywords
confining
gap
coil
open end
current
Prior art date
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EP19950105646
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English (en)
French (fr)
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EP0737531A1 (de
Inventor
Howard L. Gerber
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Inland Steel Co
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Inland Steel Co
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Publication date
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Priority to ES95105646T priority Critical patent/ES2123849T3/es
Priority to EP19950105646 priority patent/EP0737531B1/de
Priority to DE1995606225 priority patent/DE69506225T2/de
Publication of EP0737531A1 publication Critical patent/EP0737531A1/de
Application granted granted Critical
Publication of EP0737531B1 publication Critical patent/EP0737531B1/de
Priority to HK98112705.4A priority patent/HK1011626B/en
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Expired - Lifetime legal-status Critical Current

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    • 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
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0622—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars formed by two casting wheels
    • 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
    • B22D11/06—Continuous casting of metals, i.e. casting in indefinite lengths into moulds with travelling walls, e.g. with rolls, plates, belts, caterpillars
    • B22D11/0637—Accessories therefor
    • B22D11/0648—Casting surfaces
    • B22D11/066—Side dams
    • B22D11/0662—Side dams having electromagnetic confining means
    • 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
    • B22D11/11—Treating the molten metal
    • B22D11/114—Treating the molten metal by using agitating or vibrating means
    • B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
    • B22D27/00—Treating the metal in the mould while it is molten or ductile ; Pressure or vacuum casting
    • B22D27/02—Use of electric or magnetic effects

Definitions

  • the present invention relates generally to apparatuses and methods for electromagnetically confining molten metal and more particularly to an apparatus and method for preventing the escape of molten metal through the open end of a vertically extending gap between two horizontally spaced members between which the molten metal is located.
  • An example of an environment in which the present invention is intended to operate is a system for continuously casting molten metal directly into strip, e.g. steel strip.
  • a system typically comprises a pair of horizontally spaced, counter-rotating rolls defining a horizontally disposed, vertically extending gap therebetween for receiving the molten metal.
  • the gap defined by the rolls tapers in a downward direction toward the nip between the rolls.
  • the rolls are cooled, and in turn cool the molten metal as the molten metal descends through the gap, exiting as a solid metal strip at the nip between the rolls.
  • the gap has an open end adjacent each end of a roll.
  • the molten metal is unconfined by the rolls at each open end of the gap.
  • a dam must be employed to prevent molten metal from escaping outwardly through the open end of the gap.
  • Mechanical dams or seals have been used for this purpose, but they have disadvantages which are described in Pareg [sic] U.S. Patent No. 4,936,374 and in Lari, et al. U.S. Patent No. 4,974,661, and the disclosures thereof are incorporated herein by reference.
  • an electromagnet having a magnetic core encircled by an electrically conductive coil and having a pair of spaced magnet poles located adjacent the open end of the gap.
  • the magnet is energized by the flow through the coil of a time-varying current (e.g., alternating current or fluctuating direct current), and the magnet generates a time-varying magnetic field extending across the open end of the gap and between the poles of the magnet.
  • the magnetic field can be either horizontal or vertical, depending upon the disposition of the poles of the magnet. Examples of magnets which produce a horizontal field are described in the aforementioned Pareg [sic] U.S.
  • Examples of magnets which produce a vertical magnetic field are described in the aforementioned Lari, et al. U.S. Patent No. 4,974,661. The disclosures of all of these patents are incorporated herein by reference.
  • the time-varying magnetic field induces eddy currents in the molten metal adjacent the open end of the gap.
  • the induced eddy currents create their own time-varying magnetic field which, at the open end of the gap, provides a magnetic flux density which is additive to the magnetic flux density provided by the magnetic field from the electromagnet.
  • the resulting repulsive body force is directed toward the molten metal at the open end of the gap.
  • Another expedient for magnetically confining molten metal at the open end of a gap between a pair of rolls is to locate, adjacent the open end of the gap, a coil through which a time-varying current flows. This causes the coil to generate a magnetic field which induces eddy currents in the molten metal adjacent the open end of the gap resulting in a repulsive body force similar to that described above in connection with the system employing magnet poles adjacent the gap.
  • Embodiments of a coil-type of magnetic confining dam are described in Gerber, et al. U.S. Patent No. 5,197,534 and Gerber U.S. Patent No. 5,279,350, and the disclosures therein are incorporated herein by reference.
  • the coupling factor is typically less than one.
  • the coupling factor (k) can have approximate values somewhere between 0.18 and 0.90 depending upon the geometry of the molten metal pool at the open end of the gap.
  • the coupling factor decreases with increased skin depth (i.e. penetration) of the induced eddy currents in the molten metal. Skin depth increases with a reduction in frequency; therefore, a reduction in frequency results in a decrease in the coupling factor (k) which in turn decreases the repulsive body pressure (P).
  • the repulsive body pressure In order to contain the molten steel, the repulsive body pressure must be at least equal to the pressure urging the molten metal outwardly through the open end of the gap between the rolls.
  • the repulsive body pressure (P) can be increased by increasing the peak magnetic flux density (B) produced by the dam, but an increase in that flux density also increases the power loss in the dam (power dissipated as heat).
  • the power loss in the dam is reduced without any substantial decrease in the repulsive body pressure. This is accomplished by employing a conduction current in the molten metal. Such an arrangement has several advantages (described below) over an arrangement employing solely induced eddy currents in the molten metal for generating a magnetic confining field.
  • the confining coil employed in all embodiments of the present invention, has a vertically disposed first confining coil portion facing the pool of molten metal at the open end of the gap between the rolls of the continuous strip caster.
  • the bottom of the first coil portion is electrically connected to the bottom of a vertically disposed second confining coil portion.
  • An upper electrode extends into the top of the pool of molten metal adjacent the open end of the gap.
  • Other, lower electrodes or brushes (a) contact the solidified steel strip at a location just below the nip of the rolls, adjacent the open end of the gap, or (b) contact the two rolls at that location or (c) contact both the strip and the rolls as in (a) and (b) combined.
  • time-varying current is introduced into the first confining coil portion.
  • all of the current from the current source e.g. the secondary coil of a transformer
  • the current source e.g. the secondary coil of a transformer
  • one current flow is directed upwardly through the second confining coil portion
  • another current flow is directed to the lower electrodes or brushes just below the nip of the rolls and then flows upwardly, as conduction current, through the pool of molten metal to the upper electrode.
  • the current from the current source is initially provided as two, separate, discrete current flows: (a) one current flow is directed through the first and second confining coil portions as described above; (b) the other current flow is initially directed to the aforementioned lower electrodes or brushes, and it flows, as conduction current, upwardly through the molten metal, as described above.
  • the magnetic flux density (B) which produces the repulsive body pressure to confine the molten metal pool incorporates three components: (1) the magnetic flux density due to the magnetic field generated by the current flowing through the confining coil; (2) the magnetic flux density due to the magnetic field generated by the induced eddy currents in the pool of molten metal; and (3) the magnetic flux density due to the magnetic field generated by the conduction current flowing through the pool of molten metal.
  • the second component, i.e. (2) is substantially less a factor with regard to the whole of the magnetic flux density than in an arrangement in which the electric currents in the molten metal pool are solely induced eddy currents.
  • the depth of penetration of that current is not so much a function of frequency, but rather it is more a function of the placement of the electrodes.
  • the time-varying conduction current is fluctuating DC, a reduction in frequency has essentially no effect on current distribution; when the time-varying conduction current is AC, a reduction in frequency has a substantially lessened effect on current distribution than an arrangement without conduction current in the molten metal.
  • a reduction in the frequency of the time-varying conduction current does not produce a significant change in current distribution. Accordingly, there is no significant decrease in the coupling factor (k) (which decreases with increased skin depth).
  • a decrease in frequency to reduce the power loss in the confining coil does not produce a decrease in the coupling factor associated with the conduction current; nor does it produce a significant decrease in the flux density due to the magnetic field generated by the conduction current. Any negative effect on the repulsive body pressure from such a reduction in frequency would be substantially less than the negative effect resulting from a situation where the electric currents in the pool of molten metal were solely induced eddy currents.
  • the time-varying current produces a time-varying magnetic field having a corresponding frequency comprising cycles of increasing and decreasing magnetic flux density.
  • the ability of the magnetic field to contain the molten metal can be adversely affected if the frequency of the time-varying current is reduced too much.
  • the frequency cannot be reduced below a lower limit at which the time period between the peak magnetic flux density for consecutive cycles of the time-varying magnetic field is too long to prevent outflow of molten metal through the open end of the gap between the rolls.
  • the magnetic flux density generated by an arrangement in accordance with the present invention, employing conduction current in the pool of molten metal is greater than the magnetic flux density generated by an arrangement in which the current in the pool of molten metal consists solely of induced eddy currents.
  • FIG. 30 indicated generally at 30 is an electromagnetic confining apparatus for preventing the escape of molten metal 38 through the open end 36 of a vertically extending gap 35 between two horizontally spaced members 31, 32 between which a pool 38 of molten metal is located.
  • the horizontally spaced members comprise a pair of counter-rotating casting rolls of a continuous strip caster. Casting rolls 31, 32 have a nip 39 therebetween at the bottom of vertically extending gap 35.
  • the counter-rotating rolls comprise means for solidifying metal from molten pool 38 into a continuous strip 37 extending downwardly from nip 39. Rolls 31, 32 are cooled in a conventional manner not disclosed here.
  • Pool 38 is typically molten steel.
  • electromagnetic confining apparatus 30 comprises an electrically conductive, confining coil 40 adjacent open end 36 of gap 35.
  • Coil 40 generates a first horizontal magnetic field that extends toward molten metal pool 38 through open end 36 of gap 35.
  • Coil 40 comprises a vertically disposed first confining coil portion 41 facing open end 36 of gap 35 and a vertically disposed second confining coil portion 42 electrically connected at 43 to first coil portion 41. Second coil portion 42 is spaced behind and faces first coil portion 41.
  • electromagnetic confining apparatus 30 also comprises brushes 46, 47 for electrically contacting at least one of (a) strip 37 and (b) casting rolls 31, 32, at a location below nip 39 and adjacent open end 36 of gap 35.
  • Apparatus 30 further comprises an electrode 48 for electrically contacting molten metal pool 38 at a location above nip 39 and adjacent open end 36 of gap 35.
  • a transformer 50 including a primary coil 51 for receiving an input current and at least one secondary coil, e.g. 52 in Fig. 6.
  • the secondary coil comprises a pair of separate, discrete coil portions 52a and 52b.
  • the secondary coil is in the form of a center-tap coil indicated at 53.
  • first confining coil portion 41 has upper and lower ends 44, 45 respectively.
  • Vertically disposed second confining coil portion 42 has upper and lower ends 54, 55 respectively.
  • transformer 50 comprises a pair of separate, discrete secondary coil portions 52a and 52b. Each secondary coil portion includes a pair of opposite coil termini.
  • Line 56 electrically connects one terminus 70 of secondary coil portion 52b to upper end 44 of first confining coil portion 41.
  • Return line 57 electrically connects the other terminus 71 of secondary coil portion 52b to the upper end 54 of second confining coil portion 42.
  • Line 58 electrically connects one terminus 60 of secondary transformer coil portion 52a to brushes 46, 47 via branch lines 58a, 58b respectively (Fig. 3).
  • Return line 59 electrically connects the other terminus 61 of the transformer's secondary coil portion 52a to electrode 48.
  • Lines 56 and 57 comprise first conductor means for directing a time-varying electric current from transformer 50 through first coil portion 41, in a first vertical direction (downwardly in Fig. 5), and then through second coil portion 42 in a second vertical direction opposite the first vertical direction, i.e. upwardly through second coil portion 42. More particularly, current from the transformer's secondary coil portion 52b flows through line 56, then downwardly through first confining coil portion 41, then through electrical connection 43, connecting the bottoms 45, 55 of coil portions 41 and 42, then upwardly through second confining coil portion 42 and then through return line 57 to secondary coil portion 52b. The time-varying current flowing through the confining coil portions 41, 42 generates a first horizontal magnetic field adjacent open end 36 of gap 35.
  • Electrically conductive line 58, branch lines 58a, 58b, brushes 46, 47, electrode 48 and electrically conductive return line 59 comprise second conductor means for directing a time-varying electric current, from the transformer's secondary coil portion 52a, vertically through molten metal pool 38, as conduction current, adjacent open end 36 of vertically extending gap 35.
  • the flow of conduction current through pool 38 is in a direction opposite that of the current flowing through first confining coil portion 41 (i.e. upwardly through molten metal pool 38). This flow of conduction current generates a second horizontal magnetic field adjacent open end 36 of gap 35.
  • the directions of the currents flowing through first and second confining coil portions 41, 42 are shown at 62, 63 respectively, and the direction of conduction current flowing through molten metal pool 38 is shown at 64 (Figs. 5 and 7).
  • the directions of the first and second horizontal magnetic fields are shown at 65 and 66 respectively in Fig. 7. The two magnetic fields flow in the same direction and augment each other.
  • Confining coil 40, and the first and second conductor means comprise apparatus which, in the presence of molten metal pool 38, cooperate to provide a magnetic repulsive pressure which urges the molten metal inwardly away from open end 36 of gap 35.
  • the secondary coil of the transformer comprises a single coil 52.
  • line 56 electrically connects one terminus 90 of secondary coil 52 to upper end 44 of first confining coil portion 41.
  • Return line 57 electrically connects the upper end 54 of the second confining coil portion 42 to the other terminus 91 of secondary transformer coil 52.
  • Lower end 45 of first confining coil portion 41 is connected, through electrical connection 43 and a pair of connection lines 68 (only one of which is shown in Fig. 6) to brushes 46, 47.
  • Return line 59 connects electrode 48 to terminus 91 of secondary transformer coil 52.
  • terminus 91 is also connected to return line 57 in turn connected to the upper end 54 of second confining coil portion 42.
  • time-varying electric current flows from the transformer's secondary coil 52 through line 56, then downwardly through first confining coil portion 42, then into electrical connection 43 where the current is divided.
  • One part of the current flows upwardly through second confining coil portion 42 and then through line 57 back to the transformer's secondary coil 52.
  • Another part of the current flows through connection lines 68 into brushes 46, 47 and then upwardly through molten metal 38 to electrode 48 from which it flows through return line 59 back to the transformer's secondary coil 52.
  • the time-varying current flowing through coil 40 generates a first horizontal magnetic field having a direction shown at 65 in Fig. 7; the time-varying conduction current flowing through molten metal pool 38 generates a second horizontal magnetic field having a direction shown at 66 in Fig. 7. These are the same directions as the magnetic fields generated by the embodiment of Fig. 5.
  • the second horizontal magnetic field having a direction indicated at 66 in Fig. 7, augments the first horizontal magnetic field, having a direction indicated by 65 in Fig. 7, to increase the magnetic repulsive pressure at the open end 36 of gap 35.
  • the conduction current flowing vertically through molten metal pool 38 always flows in a direction 64 opposite the direction 62 of the current flowing vertically through first confining coil portion 41.
  • the direction 66 of the horizontal magnetic field generated by the conduction current flowing through molten metal pool 38 is always the same as the direction 65 of the horizontal magnetic field generated by coil 40.
  • eddy currents induced by the first horizontal magnetic field and flowing in the same direction 64 as the conduction current.
  • the horizontal magnetic field generated by the induced eddy currents flows in the same direction 66 as the horizontal magnetic field generated by the conduction current flowing through the molten metal pool, and augments the horizontal magnetic field generated by the conduction currents and by the time-varying current flowing through the confining coil 40.
  • Figs. 5 and 6 illustrate embodiments in which the time-varying current is AC.
  • the time-varying electric current may also be fluctuating DC.
  • An embodiment employing fluctuating DC is illustrated in Fig. 10.
  • the embodiment of Fig. 10 is similar to the embodiment of Fig. 6, with certain differences. The similarities will not be repeated. The differences are described below.
  • Transformer 50 in Fig. 10 has a secondary coil 72 with a center tap 73 connected to return lines 57 and 59. Each end of secondary coil 72 is connected to a respective rectifier 74, 75 each in turn electrically connected to line 56 for directing current into the upper end 44 of first confining coil portion 41. Fluctuating DC current from rectifiers 74, 75 flows downwardly through first confining coil portion 41.
  • first confining coil portion 41 As the current leaves first confining coil portion 41, at its lower end 45, the current is divided into two parts: a first part of the divided current is directed through electrical connection 43 into second confining coil portion 42 and flows upwardly therethrough; a second part of the divided current is directed through electrical connections 68 and brushes 46, 47 into molten metal pool 38 through which the second part of the current flows upwardly.
  • Return line 57 connects current flowing from the upper end 45 of second confining coil portion 42 to center tap 73 on secondary transformer coil 72, and return line 59 connects current flowing from electrode 48 to center tap 73.
  • part of the current flowing downwardly through first confining coil portion 41 also flows through molten metal pool 38.
  • no part of the current flowing through molten metal pool 38 flows through any part of confining coil 40.
  • the horizontal magnetic fields generated by the time-varying current flowing through confining coil 40 and by the conduction current flowing through molten metal pool 38 cooperate to provide a magnetic repulsive pressure which urges molten metal pool 38 inwardly away from open end 36 of gap 35.
  • first confining coil portion 41 comprises a front face 76, a rear face 77 and a pair of opposite sides 78, 79.
  • a magnetic member 80 electrically insulated from first coil portion 41, typically by a thin layer of insulation (not shown).
  • Magnetic member 80 is typically composed of conventional magnetic material and defines a low reluctance return path for the magnetic field generated by the time-varying current flowing through confining coil 40.
  • Magnetic member 80 comprises a pair of arm portions 81, 82 each located on a respective opposite side 78, 79 of first coil portion 41 and each extending in the direction of open end 36 of gap 35.
  • Magnetic member 80 also comprises a rear connecting portion 83 extending between arm portions 81, 82 and located between first and second confining coil portions 41, 42.
  • the apparatus of the present invention is devoid of any magnetic shield on the outside of magnetic arm portions 81, 82.
  • Such a shield has been employed to confine the magnetic field generated by the confining coil to a space adjacent open end 36 of gap 35. This is important where one relies upon induced eddy currents in molten metal pool 38 as the primary current source for the horizontal magnetic field generated by current flowing through molten metal pool 38.
  • conduction current is the primary source of current for the horizontal magnetic field generated by current flowing through molten metal pool 38. Accordingly, the magnetic shield of Gerber, et al. '534 is not necessary.
  • Electrode 48 is disposed between casting rolls 31, 32, above nip 39 (Fig. 2). Electrode 48 is composed of an electrically conductive material which is resistant to the high temperature of molten metal pool 38 into which electrode 48 is at least partially immersed. Electrode 48 may be composed of graphite, for example.
  • Casting rolls 31, 32 may be composed of copper, or copper alloy, or a ceramic material or austenitic (non-magnetic) stainless steel.
  • a casting roll composed of ceramic material is not very conductive electrically.
  • the relevant electrical connection to molten metal pool 38 is through brushes 46, 47 and strip 37.
  • a spring is employed to urge the brush into contact with strip 37, and such a spring is shown representationally at 85 in Fig. 9.
  • the relevant electrical connection to molten metal pool 38 includes the casting rolls.
  • the relevant electrical connection is between a brush 46, 47 and a roll 31, 32; the connection may additionally be between a brush and strip 37.
  • a spring 86 is employed to urge the brush into contact with the casting roll, and such a spring is shown representationally at 86 in Fig. 8.
  • Brushes 46, 47 are composed of an electrically conductive material, such as graphite or phosphor bronze.
  • a brush When a brush is composed of metal (such as phosphor bronze), it may be internally cooled. When the brush is composed of graphite, cooling may be effected by employing a brush holder which is internally cooled. Cooling arrangements of the types described in the preceding parts of this paragraph are within the skill of the art.

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Continuous Casting (AREA)

Claims (22)

  1. Ein Gießsystem mit einer Gießvorrichtung und einer elektromagnetischen Eindämmvorrichtung (30), wobei die Gießvorrichtung zwei horizontal beabstandete Elemente (31, 32) umfaßt, die einen sich vertikal erstreckenden Spalt (35) bilden, in dem sich ein Bad mit geschmolzenem Metall (38) befindet, wobei der Spalt eine offene Seite (36) aufweist und die elektromagnetische Eindämmvorrichtung (30) ein Austreten des geschmolzenen Metalls (38) durch die offene Seite (36) verhindert, ferner die elektromagnetische Eindämmvorrichtung (30) elektrisch leitfähige Eindämmspuleneinrichtungen (40) benachbart zu der offenen Seite (36) des Spaltes (35) zum Erzeugen eines ersten horizontalen Magnetfeldes umfaßt, das sich durch die offene Seite (36) des Spaltes (35) zu dem Bad mit geschmolzenem Metall (38) erstreckt, wobei die Eindämmspuleneinrichtung (40) einen vertikal angeordneten ersten Eindammspulenbereich (41), der zu der offenen Seite (36) des Spaltes (35) zeigt, und einen vertikal angeordneten zweiten Eindämmspulenbereich (42) umfaßt, der mit dem ersten Spulenbereich (41) elektrisch verbunden und sich in einem Abstand hinter dem ersten Spulenbereich befindet und zu dem ersten Spulenbereich zeigt, wobei die elektromagnetische Eindämmvorrichtung (30) außerdem eine erste Leitereinrichtung (56, 57) zum Lenken eines zeitlich variierenden elektrischen Stromes durch einen der Spulenbereiche in einer ersten vertikalen Richtung und dann durch den anderen Spulenbereich in einer zweiten vertikalen Richtung, die zu der ersten vertikalen Richtung entgegengesetzt ist, umfaßt, um ein erstes horizontales Magnetfeld benachbart zu der offenen Seite (36) des Spaltes (35) zu erzeugen, wobei die elektromagnetische Eindämmvorrichtung (30) gekennzeichnet ist durch:
    eine zweite Leitereinrichtung (46 bis 48, 59 und entweder 58, 58a, 58b oder 68) zum Lenken des zeitlich variierenden elektrischen Stromes vertikal durch das Schmelzebad (38) als Leitungsstrom benachbart zu der offenen Seite (36) des sich vertikal erstreckenden Spaltes (35) in einer zu derjenigen des durch den ersten Spulenbereich (41) fließenden Stromes entgegengesetzten Richtung, um ein zweites horizontales Magnetfeld benachbart zu der offenen Seite (36) des Spaltes (35) zu erzeugen;
    wobei die Eindämmspuleneinrichtung (41, 42), die erste Leitereinrichtung (56, 57) und die zweite Leitereinrichtung (46 bis 48, 59 und entweder 58, 58a, 58b oder 68) bei Anwesenheit des Schmelzebades (38) zusammenwirken, um einen magnetischen Abstoßungsdruck zu liefern, der das geschmolzene Metall (38) von der offenen Seite (36) des Spaltes (35) nach innen weg drückt.
  2. Ein Gießsystem nach Anspruch 1, dadurch gekennzeichnet, daß
    die horizontal beabstandeten Elemente (31, 32) ein Paar sich gegensinnig drehende Gießwalzen einer Endlosstreifengießvorrichtung umfassen;
    die Gießwalzen an der Unterseite des sich vertikal erstreckenden Spaltes (35) einen Walzenspalt (39) zwischen sich aufweisen;
    und die sich gegensinnig drehenden Walzen (31, 32) eine Einrichtung zum Verfestigen des Metalls aus dem Schmelzbad (38) in einen Endlosstreifen (37) aufweisen, der sich von dem Walzenspalt (39) nach unten erstreckt.
  3. Ein Gießsystem nach Anspruch 2, und umfassend:
    eine Transformatoreinrichtung (50), die eine Primärspuleneinrichtung (51) zum Empfangen eines Eingangsstromes und wenigstens eine Sekundärspuleneinrichtung (52 oder 53) zum Verbinden der ersten und zweiten Leitereinrichtungen einschließt.
  4. Ein Gießsystem nach Anspruch 3, dadurch gekennzeichnet, daß die zweite Leitereinrichtung umfaßt:
    eine Bürsteneinrichtung (46, 47) zum elektrischen Kontaktieren wenigstens eines von (a) Streifen (37) und (b) einer Gießwalze (31 oder 32) an einem Ort unter dem Walzenspalt (39) und benachbart zu der offenen Seite (36) des Spaltes (35);
    und eine Elektrodeneinrichtung (48) zum elektrischen Kontaktieren des Schmelzebades (38) an einem Ort über dem Walzenspalt (39) und benachbart zu der offenen Seite (36) des Spaltes (35).
  5. Ein Gießsystem nach Anspruch 4, dadurch gekennzeichnet, daß
    der vertikal angeordnete erste Eindämmspulenbereich (41) obere und untere Enden (44, 45) aufweist;
    die Sekundärspuleneinrichtung des Transformators (50) eine einzige Spule (52) aufweist;
    die erste Leitereinrichtung eine Einrichtung (56) zum Lenken des Stromes von der einzigen Sekundärspule (52) des Transformators (50) in das obere Ende (44) des ersten Eindämmspulenbereiches (41) umfaßt;
    und die zweite Leitereinrichtung eine Einrichtung (68) zum elektrischen Verbinden des unteren Endes (45) des ersten Eindämmspulenbereiches (41) mit der Bürsteneinrichtung (46) umfaßt.
  6. Ein Gießsystem nach Anspruch 4, dadurch gekennzeichnet, daß
    jeder der vertikal angeordneten ersten und zweiten Eindämmspulenbereiche (41, 42) obere und untere Enden (44, 54 und 45, 55) aufweist;
    die Sekundärspuleneinrichtung des Transformators (50) ein Paar separate, diskrete Sekundärspulen (52a, 52b) umfaßt;
    jede der Sekundärspulen (52a, 52b) des Transformators (50) ein Paar Anschlüsse (60, 61 und 70, 72) einschließt;
    die erste Leitereinrichtung (a) eine erste Einrichtung (56) zum elektrischen Verbinden eines Anschlusses (70) einer Sekundärtransformatorspule (52b) mit dem oberen Ende (44) eines vertikal angeordneten Eindämmspulenbereiches (41) und (b) eine zweite Einrichtung (57) zum elektrischen Verbinden des anderen Anschlusses (71) der einen Sekundärtransformatorspule (52b) mit dem oberen Ende (54) des anderen vertikal angeordneten Eindämmspulenbereiches (42) umfaßt;
    die zweite Leitereinrichtung eine Leitung (58 und entweder 58a oder 58b) zum elektrischen Verbinden eines Anschlusses (60) der anderen Sekundärtransformatorspule (52a) mit einer von (i) der Bürsteneinrichtung (46, 47) und (ii) der Elektrodeneinrichtung (48) umfaßt;
    und die zweite Leitereinrichtung außerdem eine weitere Leitung (59) zum elektrischen Verbinden des anderen Anschlusses (61) der anderen Sekundärtransformatorspule (52a) mit der anderen von (i) der Bürsteneinrichtung (46, 47) und (ii) der Elektrodeneinrichtung (48) umfaßt.
  7. Ein Gießsystem nach Anspruch 6, dadurch gekennzeichnet, daß
    die erste elektrische Verbindungseinrichtung der ersten Leitereinrichtung eine Einrichtung (56) zum elektrischen Verbinden des einen Anschlusses (70) der einen Sekundärtransformatorspule (52b) mit dem oberen Ende (44) des ersten vertikal angeordneten Eindämmspulenbereiches (41) umfaßt;
    und die eine Leitung der zweiten Leitereinrichtung eine Einrichtung (58 und 58a oder 58b) zum elektrischen Verbinden des einen Anschlusses (60) der anderen Sekundärtransformatorspule (52a) mit der Bürsteneinrichtung (46 oder 47) umfaßt.
  8. Ein Gießsystem nach Anspruch 4, dadurch gekennzeichnet, daß
    die Elektrodeneinrichtung (48) zwischen den Gießwalzen (31, 32) über dem Walzenspalt (39) angeordnet ist und eine Einrichtung zum wenigstens teilweisen Eintauchen in das Bad aus geschmolzenem Metall (38) umfaßt.
  9. Ein Gießsystem nach Anspruch 8, dadurch gekennzeichnet, daß die Elektrodeneinrichtung (48) aus Graphit zusammengesetzt ist.
  10. Ein Gießsystem nach Anspruch 4, dadurch gekennzeichnet, daß
    jede Gießwalze (31, 32) aus wenigstens einem von (a) Kupfer und (b) Kupferlegierung zusammengesetzt ist;
    und die Vorrichtung (30) eine Einrichtung (86) zum Inkontaktbringen der Bürsteneinrichtung (46, 47) mit der Walze (31, 32) umfaßt.
  11. Ein Gießsystem nach Anspruch 4, dadurch gekennzeichnet, daß
    jede Gießwalze (31, 32) aus einem keramischen Material zusammengesetzt ist;
    und die Vorrichtung eine Einrichtung (87) zum Inkontaktbringen der Bürsteneinrichtung (46, 47) mit dem Streifen (37) umfaßt.
  12. Ein Gießsystem nach Anspruch 10 oder 11, dadurch gekennzeichnet, daß
    die Bürsteneinrichtung (46, 47) aus einem von (a) Graphit und (b) Phosphorbronze zusammengesetzt ist.
  13. Ein Gießsystem nach Anspruch 4, dadurch gekennzeichnet, daß
    jede Gießwalze (31, 32) aus austenitischem Edelstahl zusammengesetzt ist.
  14. Ein Gießsystem nach Anspruch 1, und umfassend:
    ein Paar gegenüberliegende Seiten (78, 79) auf dem vertikal angeordneten ersten Eindämmspulenbereich (41);
    eine Einrichtung (80), die aus einem magnetischen Material zusammengesetzt ist, zum Bilden eines Rücklaufweges mit einem niedrigen magnetischen Widerstand für das erste Magnetfeld;
    wobei die aus einem magnetischen Material zusammengesetzte Einrichtung (80) (a) ein Paar Armbereiche (81, 82), wobei jeder sich auf einer jeweiligen entgegengesetzten Seite (78, 79) des ersten Eindämmspulenbereiches (41) befindet und sich in der Richtung der offenen Seite (36) des Spaltes (35) erstreckt, und (b) einen Verbindungsbereich (83) umfaßt, der sich zwischen den Armbereichen (81, 82) erstreckt und sich zwischen den vertikal angeordneten ersten und zweiten Eindämmspulenbereichen (41, 42) befindet;
    wobei die Vorrichtung an der Außenseite der Armbereiche (81, 82) keine magnetische Abschirmung aufweist.
  15. Ein Gießsystem nach Anspruch 1, dadurch gekennzeichnet, daß
    im Gebrauch die zweite Leitereinrichtung das zweite horizontale Magnetfeld erzeugt, um das erste horizontale Magnetfeld zu verstärken und den magnetischen Abstoßungsdruck an der offenen Seite des Spaltes zu erhöhen.
  16. Ein Gießsystem nach Anspruch 1, dadurch gekennzeichnet, daß der zeitlich variierende elektrische Strom ein Wechselstrom ist.
  17. Ein elektromagnetisches Eindämmverfahren zum Verhindern des Austritts von geschmolzenem Metall (38) durch die offene Seite eines sich vertikal erstreckenden Spaltes (35) zwischen zwei horizontal beabstandeten Elementen (31, 32), zwischen denen sich geschmolzenes Metall (38) befindet, wobei das Verfahren die Schritte des Bereitstellens einer elektrisch leitfähigen Eindämmspuleneinrichtung (40) mit einem ersten vertikal angeordneten Eindämmspulenbereich (41), der zu der offenen Seite (36) des Spaltes (35) zeigt, und einem vertikal angeordneten zweiten Eindämmspulenbereich (42), der mit dem ersten Eindämmspulenbereich (41) elektrisch verbunden ist und sich in einem Abstand hinter dem ersten Eindämmspulenbereich befindet und zu dem ersten Eindämmspulenbereich zeigt, und des Lenkens eines zeitlich variierenden elektrischen Stromes durch einen (41) der Eindämmspulenbereiche in einer ersten vertikalen Richtung und dann durch den anderen (42) der Eindämmspulenbereiche in einer vertikalen Richtung entgegengesetzt zu der ersten vertikalen Richtung, um ein erstes horizontales Magnetfeld zu erzeugen, das sich durch die offene Seite (36) des Spaltes (35) zu dem Bad mit geschmolzenem Metall (38) erstreckt, und wobei das Verfahren gekennzeichnet ist durch:
    den zusätzlichen Schritt des Lenkens des zeitlich variierenden elektrischen Stromes vertikal durch das Schmelzebad (38) als ein Leitungsstrom benachbart zu der offenen Seite (36) des Spaltes (35) in einer zu derjenigen des durch den ersten Spulenbereichs (41) fließenden Strom entgegengesetzten Richtung, um ein zweites horizontales Magnetfeld benachbart zu der offenen Seite (36) des Spaltes (35) zu erzeugen; und dadurch daß
    die vorangehend genannten Schritte zusammenwirken, um einen magnetischen Abstoßungsdruck zu liefern, der das geschmolzene Metall (38) von der offenen Seite (36) des Spaltes (35) weg nach innen drückt.
  18. Ein Verfahren nach Anspruch 17, dadurch gekennzeichnet, daß
    das zweite horizontale Magnetfeld das erste horizontale Magnetfeld verstärkt, um den magnetischen Druck an der offenen Seite (36) des Spaltes (35) zu erhöhen.
  19. Ein Verfahren nach Anspruch 17 und umfassend:
    Bereitstellen eines Rücklaufweges (81, 83, 82) mit einem niedrigen magnetischen Widerstand, der aus einem magnetischen Material zusammengesetzt ist, für das erste Magnetfeld und ohne eine magnetische Abschirmung für den Rücklaufweg.
  20. Ein Verfahren nach Anspruch 18 und umfassend:
    Lenken des Stromes durch den ersten Eindämmspulenbereich (41) nach unten;
    Aufteilen des Stromes in zwei Teile, wenn der Strom den ersten Eindämmspulenbereich (41) verläßt;
    Lenken eines ersten Teiles des aufgeteilten Stromes durch den zweiten Eindämmspulenbereich (42) nach oben;
    und Lenken eines zweiten Teiles des aufgeteilten Stromes durch das Bad mit geschmolzenem Metall (38) als besagten Leitungsstrom nach oben.
  21. Ein Verfahren nach Anspruch 17 und umfassend:
    Lenken eines ersten Stromflusses durch den ersten Eindämmspulenbereich (41) nach unten;
    Liefern eines zweiten Stromflusses, der nicht durch die Eindämmspuleneinrichtung (40) fließt;
    und Lenken des zweiten Stromflusses durch das Bad mit geschmolzenem Metall (38) als besagten Leitungsstrom nach oben.
  22. Ein Verfahren nach Anspruch 17, dadurch gekennzeichnet, daß der zeitlich variierende elektrische Strom ein Wechselstrom ist.
EP19950105646 1995-04-13 1995-04-13 Elektromagnetisches Zurückhalten von Schmelze mittels Stromerregung Expired - Lifetime EP0737531B1 (de)

Priority Applications (4)

Application Number Priority Date Filing Date Title
ES95105646T ES2123849T3 (es) 1995-04-13 1995-04-13 Confinamiento electromagnetico de metal fundido con ayuda de corriente conductiva.
EP19950105646 EP0737531B1 (de) 1995-04-13 1995-04-13 Elektromagnetisches Zurückhalten von Schmelze mittels Stromerregung
DE1995606225 DE69506225T2 (de) 1995-04-13 1995-04-13 Elektromagnetisches Zurückhalten von Schmelze mittels Stromerregung
HK98112705.4A HK1011626B (en) 1998-12-02 Electromagnetic confinement of molten metal with conduction current assistance

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
EP19950105646 EP0737531B1 (de) 1995-04-13 1995-04-13 Elektromagnetisches Zurückhalten von Schmelze mittels Stromerregung

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EP0737531A1 EP0737531A1 (de) 1996-10-16
EP0737531B1 true EP0737531B1 (de) 1998-11-25

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Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5197534A (en) * 1991-08-01 1993-03-30 Inland Steel Company Apparatus and method for magnetically confining molten metal
DE69224904T2 (de) * 1992-06-22 1998-07-16 Inland Steel Co Vorrichtung und Verfahren zum Eindämmen flüssigen Metalls durch Magnetismus

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DE69506225T2 (de) 1999-04-29
HK1011626A1 (en) 1999-07-16
ES2123849T3 (es) 1999-01-16
DE69506225D1 (de) 1999-01-07

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