DE102004044637B3 - Controlled solidification plant for melts of electrically conductive material includes an annular cathode and several annular part anodes spaced out from each other - Google Patents

Abstract

The controlled solidification plant includes a container (3) for the material (2), an annular cathode (4), and several part anodes (5I>, 5II>, 5III>, 5IV>) spaced out from each other in a jacket (9). There are insulation rings (12, 12', 12", 12''') between the part anodes. There is a magnetic coil (6) passing radially around the jacket.

Description

The The invention relates to a plant for the controlled solidification of melts electrically conductive media in containers with cathode and anode and a magnetic coil surrounding both electrodes, one through the medium flowing through electric current and a magnetic field generated by the magnetic coil itself to cut.

application areas The invention relates to metallurgy, especially in melts with progressive solidification front. This is a good mix the melting guaranteed and avoided segregation of alloying constituents. The Mixing is a stirring following process. A special application is the continuous one Continuous casting.

In the conventional one Plant are the electric current and the magnetic field at least nearly perpendicular to each other and the resulting Lorentz force drives the liquid / melt in azimuthal motion in the form of a rotation in the container. By the centrifugal forces the rotating fluid At the same time, meridional vortices occur, so that in total a good mixing takes place.

• – eine Kristallisatorvorrichtung mit zwei Enden, die mit einer Schmelze befüllbar ist, die aus den Metallen hergestellt ist,
• – eine Homogenisierungsvorrichtung, die in den Kristallisator eingebaut ist und mit ihm in Verbindung steht,
• – Zuleitungsvorrichtungen, die an den beiden Enden der Kristallisatorvorrichtung zum Durchfließenlassen eines Gleichstroms durch die Schmelze in der Kristallisatorvorrichtung angebracht sind, um darin ein elektrisches Feld von zuvor festgelegter Stärke zu erzeugen,
• – mindestens einen Elektromagnet mit Pollücken, die die Kristallisatorvorrichtung umspannen und zur Erzeugung eines magnetischen Feldes von zuvor festgelegter Induktion darin eingestellt sind, und
• – eine Kühlvorrichtung, um die Schmelze innerhalb eines zuvor festgelegten Zeitraums zum Erstarren zu bringen,

wobei bei Gebrauch der Vorrichtung das elektrische Feld und das magnetische Feld einander kreuzen. Es entsteht eine Wechselwirkung zwischen dem elektrischen Feld, das durch den die Schmelze durchfließenden Gleichstrom erzeugt wird, und dem magnetischen Feld, das durch den zumindest einen Elektromagnet erzeugt wird, die Wirkung der Schwerkraft modifiziert, wodurch ein neutrales Gleichgewicht der Komponenten der Legierung erzeugt wird.A device for casting a homogeneous alloy is in the document EP 0 545 607 B1 described and includes

• A crystalliser having two ends, which can be filled with a melt made of the metals,
• A homogenizing device incorporated in and communicating with the crystallizer,
• Supply devices mounted at both ends of the crystallizer device for flowing a direct current through the melt in the crystallizer device to generate therein an electric field of predetermined strength,
• - At least one electromagnet with pole gaps, which span the crystallizer and are set for generating a magnetic field of predetermined induction therein, and
• A cooling device to solidify the melt within a predetermined period of time,

wherein, in use of the device, the electric field and the magnetic field intersect each other. An interaction arises between the electric field generated by the direct current flowing through the melt and the magnetic field generated by the at least one electromagnet, which modifies the action of gravity, thereby producing a neutral balance of the components of the alloy.

One Problem is that there are no switch-controlled electrodes gives. There is also no strong rotation of the liquid phase. The movement the liquid Phase has three-dimensional character. There is no symmetry in the generated Lorentz force.

Another electromagnetic stirring method for continuous casting molds is in the document EP 1001862 B1 described, wherein the molds have plates and are used in the continuous casting of sticks, blocks, round pieces, wherein means are used to generate a magnetic field, which acts on the cast metal in the mold. Each plate or group of plates is electrically insulated longitudinally from the adjacent plates or the subsequent group of plates and cooperates with its own means of generating an electric current. The main component of the stream has a direction parallel to the casting axis of the mold and the desired intensity and direction.

At least some of the plates are electrically connected in series and will powered. The plates themselves can be divided into several longitudinal segments be divided electrically isolated.

One The problem is that there are no external magnetic coils. The Magnetic field is generated by an electric current passing through the side walls of the crystallizer flows. The direction of the generated Lorentz force is perpendicular to the axis the melt. There are no switch-controlled electrodes.

A device for electrodynamic stirring of the sump of a metal slab is in the document DE 33 22 891 A1 described. The device is connected to a metallic support roller frame, which consists of upper and lower rollers, which passes through a metal slab outside of the casting mold, in the in a support roller frame part, an electric current in the direction of the slab is passed through the slab. In the support roller frame part there are two pairs of rollers, one pair consisting of a lower roller and the opposite upper roller, in which the lower roller and the upper roller are provided with at least one concentric to the axis of rotation just under the outer roller shell laid field coil over Current couplings are fed with a direct current, wherein either the current directions or the winding sense of the field coils are chosen so that in the slab between each pair of rollers aligned transversely to the slab running direction, either only one direction or side by side, opposite directions possessing magnetic field arises, with the condition that the direction of the magnetic field between the one pair of rollers is opposite to the direction of the magnetic field between the other pair of rollers.

One The problem is that the geometry of the device is cuboid. The magnetic field is generated perpendicular to the axis of the melt. It There are no switch-controlled electrodes.

• – einen quaderförmigen Behälter, in dem sich die Schmelze befindet,
• – einen Eisenkern, in dessen Spalt der Behälter eingebracht ist,
• – eine Feldwicklung zur Herstellung eines magnetischen Feldes in der Schmelze,
• – eine Gleichstromquelle,
• – einen Unterbrecher des Stromkreises der Feldwicklung und
• – Elektroden in Elektrodenhalterungen, die auf einer Deckelplatte platziert sind, die senkrecht zur magnetischen Achse der Feldwicklung ist.

It is further an apparatus for processing a melt with electromagnetic forces in the document SU 159 88 59 A3 describes the following functional units:

• A cuboid container in which the melt is located,
• An iron core, in the gap of which the container is inserted,
• A field winding for producing a magnetic field in the melt,
• A direct current source,
• - A breaker of the circuit of the field winding and
• - Electrodes in electrode holders, which are placed on a cover plate, which is perpendicular to the magnetic axis of the field winding.

The Device contains an additional Field winding, which is connected to the circuit of the electrodes and placed on the iron core coaxial with the field winding.

One Problem is that the Lorentz force generated by a device This is to create an additional pressure along the Melt is used to squeeze the solidified melt. The Electrodes remain in the solid melt after their solidification. The electric current and the magnetic field that is generated are highly dependent from the time.

Of the Invention is based on the object to dampen the instabilities and grain growth (CET) during to control the solidification of alloys.

• – einen Behälter, in dessen Behälterraum das Medium einfüllbar ist,
• – eine dem Boden zugeordnete ringförmige Katode und mehrere im Mantel voneinander beabstandete ringförmige Teilanoden,
• – jeweils zwischen der Katode und den Teilanoden und zwischen den Teilanoden selbst befindliche Isolationsringe,
• – die Magnetspule, die radial den Mantel umgibt und deren Magnetflussdichte B den Boden und das Medium durchsetzt, wobei zumindest zueinander senkrecht gerichtete Komponenten von Strom j_r und Magnetflussdichte B_z eine azimutale Mediumrotationen erzeugende Lorentz-Kraft F_θ ergeben,
• – eine mit dem Boden verbundene Kühlvorrichtung,
• – elektrische Versorgungsleitungen für die Katode, die Teilanoden sowie für die Magnetspule und
• – Anoden-Stromregler für die Teilanoden zur gesteuerten Schaltung während der vom Boden aus parallel zur Behälterachse fortschreitenden Erstarrungsfront, wobei die Anoden-Stromregler mit einer stromversorgenden Steuer-/Regeleinrichtung in Verbindung stehen.

The object of the invention is solved by the features of patent claim 1. The plant for the controlled solidification of melts of electrically conductive media in a container with cathode and anode and a magnetic coil surrounding the electrodes, wherein an electric current j flowing through the medium and a magnetic flux density B generated by the magnetic coil intersect, according to claim 1

• A container in whose container space the medium can be filled in,
• A ring-shaped cathode assigned to the bottom and a plurality of ring-shaped partial anodes spaced apart from one another in the shell,
• In each case insulation rings located between the cathode and the partial anodes and between the partial anodes themselves,
• - the magnetic coil radially surrounds the cladding and whose magnetic flux density B through the bottom and the medium, wherein at least mutually perpendicular directional components of current j _r and magnetic flux density B _for an azimuthal medium rotations generating Lorentz force F _θ shown
• A cooling device connected to the floor,
• - Electric supply cables for the cathode, the partial anodes and for the magnetic coil and
• - Anode current controller for the part anodes for controlled circuit during the progressing from the bottom parallel to the container axis solidification front, wherein the anode current controller are connected to a power-supplying control device.

The bottom-side cooling device is preferably with an inflow and an outflow for a planned temperature-controlled coolant Mistake.

Of the container jacket has a comprehensive insulation protection jacket.

• – einen Behälter, in dessen Behälterraum das Medium einfüllbar ist,
• – eine dem Mantel zugeordnete, im Öffnungsbereich befindliche, ringförmige Anode und mehrere im Boden voneinander beabstandete ringförmige Teilkatoden,
• – jeweils zwischen der Anode und den Teilkatoden und zwischen den Teilkatoden selbst befindliche Isolationsringe,
• – die Magnetspule, die radial den Mantel umgibt und deren Magnetflussdichte B den Boden und das Medium durchsetzt, wobei zumindest zueinander senkrecht gerichtete Komponenten von Strom j_r und Magnetflussdichte B_z eine azimutale Mediumrotationen erzeugende Lorentz-Kraft F_θ ergeben,
• – eine mit dem Mantel verbundene Kühlvorrichtung,
• – elektrische Versorgungsleitungen für die Teilkatoden, die Anode sowie für die Magnetspule und
• – Katoden-Stromregler für die Teilkatoden zur gesteuerten Schaltung der radial vom Mantel aus zur Behälterachse gerichtet fortschreitenden Erstarrungsfront, wobei die Kato den-Stromregler mit einer stromversorgenden Steuer-/Regeleinrichtung in Verbindung stehen.

A further system for the controlled solidification of melts of electrically conductive media in containers with cathode and anode and a magnetic coil surrounding the electrodes, wherein an electric current j flowing through the medium and a magnetic flux density B generated by the magnetic coil intersect, according to claim 4

• A container in whose container space the medium can be filled in,
• A ring-shaped anode located in the opening region and associated with the jacket, and a plurality of ring-shaped partial cathodes spaced apart from each other in the bottom,
• In each case insulation rings located between the anode and the partial cathodes and between the partial cathodes themselves,
• - the magnetic coil radially surrounds the cladding and whose magnetic flux density B through the bottom and the medium, wherein at least mutually perpendicular directional components of current j _r and magnetic flux density B _for an azimuthal medium rotations generating Lorentz force F _θ shown
• A cooling device connected to the jacket,
• - Electrical supply lines for the partial cathodes, the anode and for the magnetic coil and
• - Cathode current regulator for the sub-cathodes for controlled switching of radially directed from the jacket to the container axis progressive solidification front, wherein the Kato den-current controller with a power-supplying control / regulating device in connection.

The jacket-surrounding cooling device is with an inflow and outflow for a preferably temperature controllable coolant Mistake.

Of the container bottom can have a bottom insulation protection.

Of the container can be pot-shaped, kettle-like, cylindrical or the like. be educated.

The Anode is located in the upper open area of the shell, so at most far from the partial cathodes.

The Partial electrodes are available with the respective power supply control / regulating devices in conjunction, the current controller hardware and / or programmatically are formed, each sub-electrode associated with a current regulator is. The current regulators can be formed switched off.

With the flow regulators are stirring locally different current densities j and as a result different flow conditions in the electrically conductive liquid Medium adjustable.

Reached the solid phase of the solidification front is a partial anode or a partial cathode, becomes the partial electrode by detecting a temporal current change on the part electrode by the associated turn-off current regulator off. The conductivity the solidification mass is approximately two times larger than the conductivity the liquid Phase. The bigger stream in the solid phase no more to stir the liquid Phase at.

Preferably Detector circuits are present, each with the partial anodes or partial cathodes, and the signals to power switch preferably located in the electrode associated flow controllers if for the temporal change of current corresponding solidification conditions enter, wherein the partial electrodes in contact with the solidification front be switched off because the current flowing here is no longer for stirring the electrically conductive liquid Contributes to the medium.

There both the turn-off conditions in current detection for both the vertical progressive solidification front (partial anode formation with bottom cooling system) as well as for the radially advancing solidification front (partial cathode formation with jacket cooling system) equally can apply for both Teilelektrodenausbildungen summarized the Ausschaltbedingungen become.

was als Anzeige gelten kann und erkannt wird, dass die Erstarrungsfront der i-ten Teilelektrode nahe ist, wobei

Δt

– der Zeitintervall der Stromdetektion;

ΔI

– Stromdifferenzen zwischen den Zeitintervallen der Stromdetektion;

i

– die laufende Nummer (') der i-ten Teilelektrode, die von der Erstarrungsfront noch nicht kontaktiert und noch nicht ausgeschaltet ist, sind.

A general first switch-off condition is given below:
One of the constituent solidification front nearest i-th sub-electrode is turned off in the case when:
On the adjacent, the solidification front farther (i + 1) th sub-electrode is in each case a current drop ΔI _{i + 1} in the time .DELTA.t with

which can be regarded as a display and it is recognized that the solidification front of the i-th partial electrode is close, wherein

.delta.t

The time interval of the current detection;

.DELTA.I

- Current differences between the time intervals of the current detection;

i

- the serial number (') of the i-th sub-electrode, which is not yet contacted by the solidification front and not yet turned off, are.

The respective i-numbering (') takes place from the ground upwards for the floor cooling system and directed radially from the wall to the z-container axis for the jacket cooling system.

The farthest nth partial electrode, eg the uppermost partial anode or the partial cathode associated with the floor center, is switched off only in the case when all the liquid medium in the container has solidified. The criterion for this is a constant current with

• a) In der Zeit Δt gibt es einen kurzzeitigen Stromsprung ΔI_i ^t+Δt auf der i-ten Teilelektrode, die noch eingeschaltet ist, mit
  
  und
• b) auf der benachbarten, der Erstarrungsfront ferneren (i + 1)-ten Teilelektrode erfolgt jeweils ein Stromabfall ΔI_i+1 in der Zeit Δt mit
  
  was als Anzeige gelten kann und erkannt wird, dass die Erstarrungsfront der i-ten Teilelektrode sehr nahe ist, wobei Δt – der Zeitintervall der Stromdetektion; ΔI – die Stromdifferenzen zwischen den Zeitintervallen der Stromdetektion; i – die laufende Nummer (') der i-ten Teilelektrode, die von der Erstarrungsfront noch nicht kontaktiert und nicht ausgeschaltet ist, sind.

A special second switch-off condition is given by:
One of the forming solidification nearest-nearest i-th partial electrode is turned off in the case where the following happens simultaneously:

• a) In the time .DELTA.t there is a momentary current jump ΔI _i ^{t + .DELTA.t} on the ith sub-electrode, which is still on, with
  
  and
• b) on the adjacent, the solidification front farther (i + 1) -th sub-electrode is in each case a current drop ΔI _{i + 1} in the time .DELTA.t with
  
  which can be regarded as a display and it is recognized that the solidification front of the i-th partial electrode is very close, where Δt - the time interval of the current detection; ΔI - the current differences between the time intervals of current detection; i - the serial number (') of the ith sub-electrode, which is not yet contacted by the solidification front and is not turned off.

The respective i-numbering (') takes place from the ground upwards for the floor cooling system and directed radially from the wall to the z-container axis for the jacket cooling system.

The farthest nth partial electrode, eg the uppermost partial anode or the partial cathode associated with the floor center, is switched off only in the case when all the liquid medium in the container has solidified. The criterion for this is a constant current with

The means that one of the training solidification front nearest i-th sub-electrode can be turned off, depending on whether the general first or the special second off condition in the control / regulating device or in the associated computer is defined.

Of the Difference between the two switch-off conditions is the first switch-off condition corresponds to the case when the solidification front close and spaced in front of the partial electrode located. The special second switch-off condition then corresponds in the case when the solidification front reaches the ith partial electrode or has reached.

The first switch-off condition is universally applicable. The advantage of the second switch-off condition is that it is useful for influencing the instabilities in the transition zone between the flüs phase and the solidification mass (English Mushzone) is. The selection of the switch-off condition is essentially based on the properties of the alloy, whether it is a hypoeutectic or hypereutectic alloy.

The functionality is explained in more detail below:
The container is filled with molten metal. Between the individual counter electrode (eg cathode) and the partial electrodes (eg partial anodes) the potential difference is dimensioned: φ _A - φ _K. The current j arises between the counter electrode and the sub-electrodes. At the same time the connection of the magnetic coil takes place. An axial magnetic field B _z is generated within the container. The radial component of the magnetic field B _r is low compared to the axial component B _r << B _z . In the regions where the electric current j flowing through the melt and the magnetic flux density B generated by the magnetic coil intersect, a Lorentz force F _θ = -j _r B _{z is} generated which moves the melt in the azimuthal θ direction ,

Thanks to the Lorentz force F _θ , the melt is accelerated. Cooling begins either as soon as the power is turned on or at a time interval necessary to accelerate the melt. As the solidification front progresses, the current on all sub-electrodes increases. When approaching the solidification front to the edge of a partial electrode, an increase in current on the part of the electrode and simultane- ously a current drop takes place on the next spaced partial electrode.

On The reason for the behavior is the automatic disconnection of the partial electrode, closest to the Solidification front is located, founded, wherein the shutdown of the sub-electrodes are performed computer controlled can. The computer may belong to a controller.

The farthest partial electrodes only becomes complete solidification de melt off. The electricity reaches the farthest Partial electrode a fixed value and does not change over time.

• – einen Kokillen-Behälter aus
• – einer behälterwandungsimmanenten Ringanode und
• – einem Kühlring in Form einer Mantelkühlzone zur Erstarrung der Schmelze,
• – eine die Ringanode und den Kühlring umgebende kokillenbehälterexterne Magnetspule und
• – eine Eintrags-Katode, die mittig im Kokillen-Behälter angeordnet ist und in die Schmelze ragt,

wobei die Eintrags-Katode und die Ringanode derart angeordnet sind, dass der erzeugten Strom j senkrecht zum Magnetfeld geführt ist, das mit der Magnetspule erzeugt wird.Another system according to the invention for controlled solidification of melts of electrically conductive media in continuous casting in containers with cathode and anode and a magnetic coil surrounding the electrodes, wherein an electrical current flowing through the medium and a magnetic field generated by the magnetic coil intersect at least in mutually perpendicular components , contains according to claim 14,

• - a mold container
• - A container wall inherent ring anode and
• A cooling ring in the form of a jacket cooling zone for solidification of the melt,
• - A kokillenbehälterexterne magnetic coil surrounding the ring anode and the cooling ring and
• An entry cathode, which is arranged centrally in the mold container and projects into the melt,

wherein the input cathode and the ring anode are arranged such that the generated current j is guided perpendicular to the magnetic field generated with the magnetic coil.

Of the Mold container can be cylindrical.

in the Entrance area of the mold container is located externally the ring anode, which peripherally surrounded by the magnetic coil is. The entry cathode may be formed as a nozzle cathode and hang in the center of the mold container into it, the nozzle cathode immersed in the melt. The melt can in the direction of gravity flow out. The resulting Lorentz force F acts in the azimuthal direction and moves the liquid Area of the melt above the sump. The solidifying at the jacket cooling zone Melt slips towards the mold container exit and becomes but in the swamp and in the above located liquid Phase the medium still stirred. The ring anode therefore extends into the area of the sump.

Of the from the mold container pulled strand of solidified mass during the pass through the Jacket cooling zone consists of an already solidified, gradually thickening shell and a corresponding dwindling, still molten swamp.

Of the cooling ring can as a ring anode and at the same time as a mold container be educated.

further developments and specific embodiments of the invention are described in further subclaims.

The Invention will be described with reference to several embodiments by means of several Drawings closer explains:

It demonstrate:

1 a schematic front view of a first system for the controlled solidification of the melt of an electrically conductive medium with ring-like, disconnectable part anodes in the container shell and with cooled bottom, the solidification front of the melt axially directed from the bottom against the direction of gravity advances, and a perspective view of the container with outer holder Magnetic coil in 1a .

2 a schematic representation of a second system for the controlled solidification of the melt of an electrically conductive medium with ring-like, disconnectable partial cathodes in the bottom and with cooled container shell, wherein the solidification front of the melt advances directed radially from the container shell to the container axis,

3a a diagram of the current waveform I / I ₀ as a function of the relative height z _he vertically advancing solidification front with z _er / H and H as the height of the container in response to the arrangement of a central single cathode and a plurality of container shell-side partial anodes in the general first turn-off condition,

3b a diagram of the current waveform I / I ₀ as a function of the relative height z _he vertically advancing solidification front with z _er / H and H as the height of the container in response to the arrangement of a central single cathode and a plurality of container-manteliger tiger partial anodes in the special second switch-off condition,

4 a representation of the parameter size distributions in a container with cooled bottom and four annularly arranged part anodes, which are switched on and off, before the start of the cooling after 1 :

4a a meridional distribution of the electric current density,

4b : a meridional distribution of the electrical potential,

4c : a spatial distribution of the azimuthal velocity and

4d a spatial distribution of the meridional velocity,

5 a representation of the parameter size distributions in a container with cooled bottom and four annularly arranged partial anodes, four of which are turned on, at the beginning of the cooling phase after 1 ,

5a a meridional distribution of the electric current density,

5b : a meridional distribution of the electrical potential,

5c : a spatial distribution of the azimuthal velocity and

5d a spatial distribution of the meridional velocity,

6 a representation of the parameter size distributions in a container with cooled bottom and four ringför mig arranged partial anodes, of which the bottom is turned off, in the cooling phase after 1 :

6a a meridional distribution of the electric current density,

6b : a meridional distribution of the electrical potential,

6c : a spatial distribution of the azimuthal velocity and

6d a spatial distribution of the meridional velocity,

7 a representation of the parameter size distributions in a container with a cooled bottom and four annularly arranged part anodes, of which the bottom three, bottom-near are turned off, in the cooling phase after 1 :

7a a meridional distribution of the electric current density,

7b : a meridional distribution of the electrical potential,

7c : a spatial distribution of the azimuthal velocity and

7d a spatial distribution of the meridional velocity,

8th a representation of the parameter size distributions in a container with a cooled jacket wall and three annularly arranged partial cathodes, which are switched on and off, with the disconnected shell side near sub-cathode after 2 :

8a a meridional distribution of the electric current density,

8b : a meridional distribution of the electric potential,

8c : a spatial distribution of the azimuthal velocity and

8d : a spatial distribution of meridional velocity, and

9 a schematic representation of the plant for stirring molten metal during continuous casting.

The Reference numerals are for Parts with the same functions have been largely retained.

The 1 . 1a will be considered together below.

• – einen zylindrischen Behälter 3, in dessen Behälterraum 11 das Medium 2 einfüllbar ist,
• – eine dem Boden 10 zugeordnete ringförmige Katode 4 und mehrere im Mantel 9 voneinander beabstandete ringförmige Teilanoden 5', 5'', 5''', 5^IV
• – jeweils zwischen der Katode 4 und den Teilanoden 5', 5'', 5''', 5^IV und zwischen den Teilanoden 5', 5'', 5''', 5^IV selbst befindliche Isolationsringe 12, 12', 12'', 12''',
• – die Magnetspule 6, die radial den Mantel 9 umgibt und deren Magnetflussdichte B 8 den Boden 10 und das Medium 2 durchsetzt, wobei zumindest zueinander senkrecht gerichtete Komponenten von Strom j 7', 7'', 7''', 7^IV und Magnetflussdichte B 8 eine azimutale Mediumrotationen erzeugende Lorentz-Kraft F_θ 13 ergeben,
• – eine mit dem Boden 10 verbundene Kühlvorrichtung 14,
• – elektrische Versorgungsleitungen 15, 16 für die Katode 4 und die Teilanoden 5', 5'', 5''', 5^IV sowie für die Magnetspule 6 und
• – Anoden-Stromregler 17', 17'', 17''', 17^IV für die Teilanoden 5', 5'', 5''', 5^IV zur gesteuerten Schaltung der vom Boden aus parallel der Behälterachse 18 fortschreitenden Erstarrungsfront 19, wobei die Anoden-Stromregler 17', 17'', 17''', 17^IV mit einer stromversorgenden Steuer-/Regeleinrichtung 20 in Verbindung stehen.

In 1 is a schematic representation of a plant 1 for the controlled solidification of a melt of an electrically conductive liquid medium 2 in a container 3 with cathode and anode and a magnet coil surrounding both electrodes 6 , one through the medium 2 passing electric current j 7 and one from the solenoid 6 generated magnetic flux density B 8th intersect, shown. The attachment 1 contains, as well as in 1a is shown

• - a cylindrical container 3 in its container space 11 the medium 2 is fillable,
• - one to the ground 10 associated annular cathode 4 and several in the coat 9 spaced apart annular partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV
• - in each case between the cathode 4 and the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV and between the part anodes 5 ' . 5 '' . 5 ''' . 5 ^IV self-contained insulation rings 12 . 12 ' . 12 '' . 12 ''' .
• - the magnetic coil 6 that radially the coat 9 surrounds and whose magnetic flux density B 8th the ground 10 and the medium 2 interspersed, wherein at least mutually perpendicular components of current j 7 ' . 7 '' . 7 ''' . 7 ^IV and magnetic flux density B 8th an azimuthal medium rotation generating Lorentz force F _θ 13 yield,
• - one with the ground 10 connected cooling device 14 .
• - electrical supply lines 15 . 16 for the cathode 4 and the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV as well as for the magnetic coil 6 and
• - anode current regulator 17 ' . 17 '' . 17 ''' . 17 ^IV for the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV for controlled switching from the ground parallel to the container axis 18 progressive solidification front 19 , wherein the anode current regulator 17 ' . 17 '' . 17 ''' . 17 ^IV with a power supply control device 20 keep in touch.

The bottom-side cooling device 14 can be an inflow 21 and a drain 22 for a provided preferably temperaturregelbares coolant.

The container jacket can be a comprehensive insulation protective jacket 23 exhibit.

• – einen zylindrischen Behälter 25, in dessen Behälterraum 28 das Medium 2 einfüllbar ist,
• – eine dem Mantel 2b zugeordnete, im Öffnungsbereich 29 befindliche, ringförmige Anode 5 und mehrere im Boden 27 voneinander beabstandete ringförmige Teilkatoden 4''', 4'', 4',
• – jeweils zwischen der Anode 5 und den Teilkatoden 4''', 4'', 4' und zwischen den Teilkatoden 4''', 4'', 4' selbst befindliche Isolationsringe 30, 30', 30'',
• – die Magnetspule 6, die radial den Mantel 26 umgibt und deren Magnetflussdichte B 8 den Boden 27 und das Medium 2 durchsetzt, wobei zumindest zueinander senkrecht gerichtete Komponenten von Strom j 7^IV , 7^V , 7^VI und Magnetflussdichte B 8 eine azimutale Mediumrotationen erzeugende Lorentz-Kraft F_θ 31 ergeben,
• – eine mit dem Mantel 26 verbundene Kühlvorrichtung 32,
• – elektrische Versorgungsleitungen 15, 16 für die Teilkatoden 4''', 4'', 4' und die Anode 5 sowie für die Magnetspule b und
• – Katoden-Stromregler 33', 33'', 33''' für die Teilkatoden 4''', 4'', 4' zur gesteuerten Schaltung der radial vom Mantel 26 aus zur Behälterachse 18 gerichtet fortschreitenden Erstarrungsfront 34, wobei die Katoden-Stromregler 33', 33'', 33''' mit einer stromversorgenden Steuer-/Regeleinrichtung 35 in Verbindung stehen.

In 2 is a schematic view of a second plant 24 for the controlled solidification of the melt of the electrically conductive liquid medium 2 in a container 25 with cathode and anode and a magnet coil surrounding the electrodes 6 , one through the medium 2 passing electric current j 7 and one from the solenoid 6 outgoing magnetic flux density B 8th intersect, shown. The attachment 24 contains

• - a cylindrical container 25 in its container space 28 the medium 2 is fillable,
• - one the coat 2 B assigned, in the opening area 29 located, annular anode 5 and several in the ground 27 spaced apart annular Teilkatoden 4 ''' . 4 '' . 4 ' .
• - between the anode 5 and the partial cathodes 4 ''' . 4 '' . 4 ' and between the partial cathodes 4 ''' . 4 '' . 4 ' self-contained insulation rings 30 . 30 ' . 30 '' .
• - the magnetic coil 6 that radially the coat 26 surrounds and whose magnetic flux density B 8th the ground 27 and the medium 2 interspersed, wherein at least mutually perpendicular components of current j 7 ^IV . 7 ^v . 7 ^VI and magnetic flux density B 8th an azimuthal medium rotation generating Lorentz force F _θ 31 yield,
• - one with the coat 26 connected cooling device 32 .
• - electrical supply lines 15 . 16 for the partial cathodes 4 ''' . 4 '' . 4 ' and the anode 5 and for the solenoid b and
• - cathode current regulator 33 ' . 33 '' . 33 ''' for the partial cathodes 4 ''' . 4 '' . 4 ' to the controlled circuit of the radially from the jacket 26 out to the tank axis 18 directed advancing solidification front 34 where the cathode current regulator 33 ' . 33 '' . 33 ''' with a power supply control device 35 keep in touch.

The jacket-surrounding cooling device 32 can be an inflow 36 and a drain 37 for a preferably temperature-controlled coolant.

The tank bottom 27 can provide a lower insulation protection 38 exhibit.

The anode 5 is located in the upper open area of the mantle 26 So far away from the partial cathodes.

The inventive property of the container 3 . 25 is that the shell-side anode into several annular partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV or the bottom-side cathode into a plurality of annular partial cathodes 4 ''' . 4 '' . 4 ' are split, which are at least switched off. As a result, the use in stirring and mixing of melts is in each case with a progressive solidification front 19 . 34 possible. Reached the solid area of the solidification fronts 19 . 34 a partial anode 5 ' . 5 '' . 5 ''' . 5 ^IV or partial cathod 4 ''' . 4 '' . 4 ' Thus, the partial electrode is turned off by detecting a temporal current change on the partial electrode by the associated power switch, which is preferably in the electrode associated flow controller, since the large current flowing here no longer contributes to the stirring of the liquid phase. The conductivity of the solid phase is approximately two times greater than the conductivity of the liquid phase.

For this purpose detector circuits are present, each with the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV or partial cathodes 4 ''' . 4 '' . 4 ' communicate and indicate the location of the solidification front 19 ; 34 detect and give the signals to the associated power switch, preferably in the electrode associated flow controllers 17 ' . 17 '' . 17 ''' . 17 ^IV ; 33 ' . 33 '' . 33 ''' when, after contact of the solidified area of the solidification fronts 19 . 34 with the sub-electrodes, the temporal current change on the sub-electrode due to the higher conductivity of the solidification mass is detected, wherein the sub-electrodes 5 ' . 5 '' . 5 ''' . 5 ^IV respectively. 4 ''' . 4 '' . 4 ' be turned off, since the large current flowing here no longer contributes to the stirring of the electrically conductive liquid medium.

The following is the operation of the system 1 in 1 with the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV explains the operation of the system 24 with the partial cathodes 4 ''' . 4 '' . 4 ' in 2 is formed analog.

The container 3 is filled with molten metal. Between the cathode 4 and the anodes 5 ' . 5 '' . 5 ''' . 5 ^IV the potential difference is dimensioned: φ _A - φ _K. The current j arises between the electrodes 4 . 5 '; 4 . 5 ''; 4 . 5 '''; 4 . 5 ^IV , The distribution of the current density j 7 ' . 7 '' . 7 ''' . 7 ^IV and the potential φ is in the 4a and 4b shown before cooling. At the same time, the power supply of the solenoid takes place 6 , The generated magnetic field B _z is within the Behältexs 3 parallel to the z-container axis 18 available. The radial component of the magnetic field B _r is low in comparison to the axial component B _z with B _r << B _z . In the areas where the melt through 2 through which electric current j flowing through and the magnetic flux density B generated by the magnetic coil intersect, a Lorentz force F _{θ is} generated with F _θ = -j _r B _z , which is the melt 2 moved in azimuthal θ direction.

As a result of the Lorentz force F _θ , the melt begins 2 in the container 3 around the z-axis 18 to rotate. Cooling begins either simultaneously with the power on or at a time interval necessary for the acceleration of the melt 2 necessary is.

In the 3a and 3b are two graphs of the current waveform I / I ₀ in dependence on the relative height _he, for the vertically advancing solidification front with, _he / H and H as a height of the container shown. The ordinate indicates the relative current density I / I ₀ , where I _{0 is} the cathode current before cooling at the time t _{0 of} the turn-on. The abscissa is the amount _it for the progressive solidification front 19 to total height H at H = 50 mm with z _er / H. I ₀ = 4.07A corresponds to the current on cathode at time t _{0 of} the beginning of the cooling. The potentials for the anodes are φ _A = 10 ^-4 volts and for the cathode φ _K = -10 ^-4 volts and the magnetic flux density B _z = 10 ^-3 Tesla and B _r = 0 Tesla.

Parallel to this are the four partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV shown. The relative current curve 61 represents the cathode current, that of the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV to the cathode 4 total current flowing. The total current density is made up of the current components of the individual partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV together. In the area 62 delivers the first lowest partial anode 5 ' the highest proportion of electricity, while the top fourth partial anode 5 ^IV has the lowest proportion of electricity.

In the vertical progression of the solidification front 19 the current increases at all partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV , like in the 3 is shown. At an approximation of the solidification front 19 to the edge 66 the partial anode 5 ' there is a current gain on the part anodes 5 '' . 5 ''' 5 ^IV and at the same time the power take-off on the ground near first partial anode 5 ' immediately to zero. In the area 63 the current increases with ground-advancing solidification front 19 to the edge 67 the second partial anode 5 '' , The same applies for the areas 64 and 65 with the partial anodes 5 ''' . 5 ^IV ,

At the latest at the marginal approach of the solidification front 19 to the respective partial anode 5 ' . 5 '' . 5 '''takes place in each case an automatic, by the computer or the control / regulating device 20 including a power supply based shutdown of one of the partial anodes 5 ' . 5 '' . 5 ''', which is closest to the solidification front 19 located.

The top part anode 5 ^IV is turned off only at the complete melt solidification. The current reaches the upper fourth partial anode 5 ^IV the fixed value and does not change over time.

In the 3a . 3b are the diagrams of the shutdown of the partial anodes 5 ' . 5 '' . 5 ''' 5 ^IV depending on the progression of the solidification front 19 depending on the use of the general or special shutdown condition shown.

Similar to analogue diagrams, the system can 25 with the partial cathodes 4 ''' . 4 '' . 4 ' and the single anode 5 and the radially advancing, to the z-axis 18 directed solidification front 34 exhibit.

For the interaction of the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV at edge contact with the solidification front 19 the following switch-off states result.

was als Anzeige gelten kann und erkannt wird, dass die Erstarrungsfront 19 der i-ten Teilelektrode 5' nahe ist, wobei

Δt

– der Zeitintervall der Stromdetektion;

ΔI

– Stromdifferenzen zwischen den Zeitintervallen der Stromdetektion;

i

– die laufende Nummer (') der i-ten Teilanode 5', die von der Erstarrungsfront 19 noch nicht kontaktiert und noch nicht ausgeschaltet ist, sind.

A general first off condition is after 3a given below:
One of the developing solidification front 19 nearest i-th partial anode 5 ' will be turned off if the following happens:
On the neighboring, the solidification front 19 further (i + 1) th partial anode 5 '' takes place in each case a current drop ΔI _{i + 1} in the time .DELTA.t with

what can be considered an ad and it is recognized that the solidification front 19 the i-th partial electrode 5 ' is near, where

.delta.t

The time interval of the current detection;

.DELTA.I

- Current differences between the time intervals of the current detection;

i

- the serial number (') of the i-th partial anode 5 ' that of the solidification front 19 not yet contacted and not yet turned off are.

The respective i-numbering (') takes place from the ground upwards for the floor cooling system.

The farthest nth partial anode 5 ^IV , For example, the tank top part anode is turned off only in the case when the entire melt 2 in the container 3 is frozen. The criterion for this is a constant current with

The time interval Δt of the current detection and the current differences ΔI between the time intervals of the current detection with respect to the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV that of the solidification front 19 not yet contacted and not yet turned off can be monitored by a computer.

• a) In der Zeit Δt gibt es einen kurzzeitigen Stromsprung ΔI_i ^t+Δt auf der i-ten Teilanode 5', die noch eingeschaltet ist, mit
  
  und
• b) auf der benachbarten, der Erstarrungsfront 19 ferneren (i + 1)-ten Teilanode 5'' erfolgt jeweils ein Stromabfall ΔI_i+1 in der Zeit Δt mit
  
  was als Anzeige gelten kann und erkannt wird, dass die Erstarrungsfront 19 der i-ten Teilelektrode 5' sehr nahe ist, wobei Δt – der Zeitintervall der Stromdetektion; ΔI – die Stromdifferenzen zwischen den Zeitintervallen der Stromdetektion; i – die laufende Nummer (') der i-ten Teilanode 5', die von der Erstarrungsfront 19 noch nicht kontaktiert und nicht ausgeschaltet ist, sind.

A special second off condition is after 3b given by, which can also be used computer-monitored:
One of the developing solidification front 19 nearest i-th partial anode 5 ' will be turned off if the following happens:

• a) In the time .DELTA.t there is a momentary current jump ΔI _i ^{t + .DELTA.t} on the ith partial anode 5 ' that's still on, with
  
  and
• b) on the adjacent, the solidification front 19 further (i + 1) th partial anode 5 '' takes place in each case a current drop ΔI _{i + 1} in the time .DELTA.t with
  
  what can be considered an ad and it is recognized that the solidification front 19 the i-th partial electrode 5 ' is very close, where Δt - the time interval of the current detection; ΔI - the current differences between the time intervals of current detection; i - the serial number (') of the ith partial anode 5 ' that of the solidification front 19 not yet contacted and not turned off are.

The respective i-numbering (') of the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV also takes place from the ground up for the floor cooling system and analogously for the case of Teilkatoden 4 ''' . 4 '' . 4 ' directed radially from the wall to the z-container axis for the jacket cooling system.

The farthest nth partial electrode, eg the uppermost part anode 5 ^IV or the partial cathode 4 ''' which is assigned to the floor center, is turned off only in the case when the entire melt 2 in the container 3 respectively. 25 is frozen. The criterion for this is a constant current with

The means that one of the training solidification front nearest i-th partial electrode can then be turned off, depending on whether the general first or the special second switch-off condition is defined in the control device or in the associated computer.

In the representations of the 3a . 3b the following boundary conditions are given: I ₀ = 4.07 A, H = 50 mm, φ _K = -10 ^-4 V, φ _A = 10 ^-4 V, B _z = 10 ^-3 T, B _r = 0 T.

The explained switch off / shutdown procedures apply to containers 3 with the partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV and also analog for the container 25 with partial cathodes 4 ''' . 4 '' . 4 ' ,

To explain the effect of the invention are in the following 4 to 7 Boundary conditions and numerical simulations of solidification processes for the liquid metal specified.

The input data is: Density: ρ = 6000 kg / m ³ , Dynamic viscosity: μ = 2 × 10 ^-3 Ns / m ² , Conductivity: σ = 10 ⁶ A / Vm potential: φ _A = 10 ^-4 volts, φ _K = -10 ^-4 volts, Magnetic flux density: B _z = 10 ^-3 tesla.

The equations given below are for calculation and training purposes the distributions with respect to the currents indicated in the figures, the Potentials and speeds. The calculations were on a computer.

Around represent the current densities, potentials and speeds and to support the functioning, numerical simulations have been performed by means of a computer. The restriction The simulations were based on the rotationally symmetric case. The Equation system for the modeling of the solidification of the alloys is in the publication International Journal Heat Mass Transfer, 30 (10), (1987), 2161-2170: "A continuum model for momentum, heat and species transport in binary solid-liquid phase change systems - I. Model formulation "described. The system of equations was modeled using a finite-volume finite difference scheme discretized and calculated with SIMPLE algorithm.

The calculation of the Lorentz force on the case of the plant 1 for the controlled solidification of melts of electrically conductive media is carried out with the following equations:
The Lorentz force F → _L is a vector product of the electric current density j → and the magnetic flux density B →: F → L = j → × B →. (1)

The projections of the Lorentz force on the cylindrical axes have the following shape: F Lr = j θ B z - j z B θ , (2) F Lθ = j z B r - j r B z , (3) F lz = j r B θ - j θ B r , (4)

To calculate the current density, Ohm's law is included: j → = σ (E → + u → x B →). (5)

The projections of the electric current density on the cylindrical axes have the following form: j r = σ (E r + θ B z - u z B θ ), (6) j θ = σ (E θ + z B r - u r B z ) (7) j z = σ (E z + r B θ - u θ B r ). (8th)

Thus, the projections of the Lorentz force have the following form: F Lr = σ (-E z B θ - u r (B 2 z + B 2 θ + z B r B z + θ B r B θ ), (9) F Lθ = σ (E z B r - E r B z - u θ (B 2 z + B 2 r ) + B θ (u z B z + r B r )), (10) F lz = σ (E r B θ - u Z (B 2 r + B 2 θ ) + u r B r B z + θ B z B θ ). (11)

Here, it has been considered that E _θ = 0 for reasons of symmetry.

To calculate the electric current densities, the electric potential equation and the equation of continuity for the electric current density are used: E = -∇φ, (12) ∇ · j → = 0, (13)

To transforming equations (6) - (8), (12), (13) becomes the equation for the receive electrical potential:

The Equation (14) is the electrical potential calculation in the electrical conducting liquid Assigned to medium.

During the solidification process, it is expedient to assess and estimate the current heat in the electrically conductive liquid medium:
If the velocity is low compared to the heat transport due to the thermal conductivity, the one-dimensional energy equation has the following form:

After integration by the radius r is obtained:

If it is assumed that the maximum temperature difference between the cathode and the anode must become less than one degree Celsius, the following is obtained:

wobei λ die spezifische Wärmeleitfähigkeit und σ die elektrische Leitfähigkeit darstellen. Damit ist eine effektive Abkühlung möglich.If it is assumed that E _r ≈ Δφ / R, we obtain:

where λ represents the specific thermal conductivity and σ the electrical conductivity. This is an effective cooling possible.

If necessary, the melt 2 To heat up, the voltage must be at least:

H

– Höhe des Behältermantels 3

Δh

– Höhe der Teilanoden 5', 5'', 5''', 5^IV und

n

– Zahl der Teilanoden 5', 5'', 5''', 5^IV sind.

The distance D of the partial anodes on the container shell 3 corresponds to the D = H / n - Δh, where

H

- Height of the tank shell 3

.delta.h

- Height of the partial anodes 5 ' . 5 '' . 5 ''' 5 ^IV and

n

- Number of partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV are.

The The equations given are shown in the figures with the distributions of Current densities, potentials and speeds as drawings realized by program implementation in a computer.

The distributions of the calculated data for the container 3 with cooled bottom and with the partial anodes 5 ' . 5 '' . 5 ''' 5 ^IV trained container casing 3 in the 1 are shown in the 4 to 7 shown.

In 4 Figure 12 is an illustration of the parameter size distributions in the container 3 with cooled bottom and four annularly arranged partial anodes 5 ' . 5 '' . 5 ''' . 5 ^IV , which are switched on and off, after 1 before cooling down with

4a : a meridional distribution of electric current density,

4b : a meridional distribution of electrical potential,

4c : a spatial distribution of the azimuthal velocity and

4d : a spatial distribution of meridional velocity shown.

In 5 Figure 12 is an illustration of the parameter size distributions in the container 3 with cooled bottom and four annularly arranged partial anodes 5 ' . 5 '' 5 ''' 5 ^IV , which are switched on and off, after 1 with beginning bottom-side cooling with

5a : a meridional distribution of electric current density,

5b : a meridional distribution of electrical potential,

5c : a spatial distribution of the azimuthal velocity and

5d : a spatial distribution of meridional velocity shown.

In 6 Figure 12 is an illustration of the parameter size distributions in the container 3 with cooled bottom and four annularly arranged partial anodes 5 ' . 5 '' 5 ''' . 5 ^IV , which are switched on and off, after 1 during the bottom cooling, with the bottom-side lowest anode 5 ' is off, with

6a : a meridional distribution of electric current density,

6b : a meridional distribution of electrical potential,

6c : a spatial distribution of the azimuthal velocity and

6d : a spatial distribution of meridional velocity shown.

In 7 Figure 12 is an illustration of the parameter size distributions in the container 3 with cooled bottom and four annularly arranged partial anodes 5 ' . 5 '' 5 ''' . 5 ^IV , which are switched on and off, after 1 during bottom cooling, wherein the first, second, third sub-anode 5 ' . 5 '' . 5 '''are off, with

7a : a meridional distribution of electric current density,

7b : a meridional distribution of electrical potential,

7c : a spatial distribution of the azimuthal velocity and

7d : a spatial distribution of meridional velocity shown.

In 8th Figure 12 is an illustration of the parameter size distributions in the container 25 with cooled jacket wall and three annular angeodneten, bottom-side partial cathodes 4 ''' . 4 '' . 4 ' , which are switched on and off, after 2 during cooling, wherein the first wall-side Teilkatode 4 ' is switched off, with

8a : a meridional distribution of electric current density,

8b : a meridional distribution of electrical potential,

8c : a spatial distribution of the azimuthal velocity and

8d : a spatial distribution of meridional velocity shown.

The invention makes it possible for the controlled solidification of melts 2 container 3 . 25 can be used, which are formed regardless of their size. Likewise, controlled texture enhanced grain crystal growth can be brought about because the rate of rotation of the liquid phase can be made approximately constant.

Both Benefits can in improved, described below continuous casting with continuous casting containers - molds - used become.

In Extension of the object of the present invention is to improve the quality of the internal and outer structure to improve the continuously cast metals.

• – einen zylindrischen Kokillen-Behälter 41 aus
• – einer behälterwandungsimmanenten Ringanode 42 und
• – einem Kühlring 43 in Form einer Mantelkühlzone zur Erstarrung der Schmelze 2,
• – eine die Ringanode 42 und den Kühlring 43 umgebende kokillenbehälterexterne Magnetspule 44 und
• – eine Eintrags-Katode 45, die mittig im Kokillen-Behälter 41 angeordnet ist und in die Schmelze 2 ragt,

wobei die Eintrags-Katode 45 und die Ringanode 42 derart angeordnet sind, dass der erzeugten Strom j senkrecht zum Magnetfeld 46 geführt ist, das mit der Magnetspule 44 erzeugt wird. Die entstehende Lorentz-Kraft F_θ 47 wirkt in azimutale Richtung und bewegt den flüssigen Bereich der Schmelze 2 oberhalb des Sumpfes 48.There is a third, in 5 shown, inventive system 40 for controlled solidification of melts of electrically conductive media 2 in continuous casting in containers with cathode and anode and a magnetic coil surrounding the electrodes, wherein an electrical current flowing through the medium and a magnetic field generated by the magnetic coil intersect, provided, which contains

• - A cylindrical mold container 41 out
• - A container wall inherent ring anode 42 and
• - a cooling ring 43 in the form of a jacket cooling zone for solidification of the melt 2 .
• - one the ring anode 42 and the cooling ring 43 surrounding kokillenbehälterexterne magnetic coil 44 and
• An entry cathode 45 in the center of the mold container 41 is arranged and in the melt 2 protrudes,

wherein the entry cathode 45 and the ring anode 42 are arranged such that the generated current j perpendicular to the magnetic field 46 is guided, that with the magnetic coil 44 is produced. The resulting Lorentz force F _θ 47 acts in azimuthal direction and moves the liquid area of the melt 2 above the swamp 48 ,

In the entrance area of the mold container is the ring anode 42 that is peripheral to a magnet coil 44 is surrounded. Likewise, the ring anode 42 even be designed as a cooling ring and represent the cooled Kokillenbehälter. The entry cathode 45 can be designed as a nozzle cathode and depends centrally in the mold container 41 , wherein from the nozzle cathode 45 the melt 2 flows out in the direction of gravity. The melt 2 is subject to the Lorentz force F _θ 47 , wherein the at the jacket cooling zone 43 congealing mass 49 towards the mold container outlet 50 continues to slide and in the swamp 48 and in the liquid phase, the melt 2 still being stirred.

The from the mold container 41 drawn strand of solidification mass 49 while passing through the cooling ring 43 consists of an already solidified, gradually thickening shell and a corresponding dwindling, still molten swamp 48 ,

The entry cathode 45 represents a nozzle cathode, which is an insulator tube 53 upstream, through which the melt to be cast into a strand 2 in the direction 54 to the nozzle cathode 45 flows. The nozzle openings may be arranged vertically or horizontally in the nozzle discharge area. The nozzle cathode 45 is located below the surface during continuous casting 55 the melt 2 and extends into the liquid phase of the melt 2 ,

The power supply unit 51 including a controller is via the isolated supply line 56 with the nozzle cathode 45 , via the supply line 57 with the ring anode 42 and over the supply line 58 with the magnetic coil 44 connected. The cooling ring 43 each has a coolant flow 59 and a coolant drain 60 on.

The cooling ring ( 43 ) may optionally be formed as a ring anode and at the same time as a mold container.

The following is the operation based on the 9 explained in more detail.

In the flow direction 54 is via the nozzle cathode 45 the melt 2 in the mold container 41 pressed. The in eg gravity direction 54 outflowing melt 2 fills the mold container 41 , The melt contained therein 2 is subject to the Lorentz force F _θ 47 , The at the jacket cooling zone 43 forming solidification mass 49 slips towards the mold container exit 50 continue and become the controlled grain growth in the bottom and in the liquid phase of the melt above it 2 still stirred.

The from the mold container 41 the line drawn during the pass through the ring anode cooling ring area 42 / 43 from an already solidified, gradually thickening shell and a corresponding dwindling, still molten swamp 48 ,

In order to achieve a uniform structure and to evenly distribute segregations over the strand cross-section, the still liquid melt 2 stirred under the influence of the flowing current j and the magnetic field B in the cathode-ring anode region. For this purpose, the cathode 45 and the ring anode 42 arranged so that the current j 61 or a component thereof perpendicular to the magnetic field B 46 is directed, that with the magnetic coil 44 is produced. The resulting Lorentz force F _θ acts in the azimuthal direction and produces a meridional swirl 52 ,

1

first investment

2

medium

3

container

4

cathode

4 '

first Teilkatode

4 ''

second Teilkatode

4 '' '

third Teilkatode

5

anode

5 '

first part anode

5 ''

second part anode

5 '' '

third part anode

5 ^IV

fourth part anode

6

external solenoid

7

electrical Current j

8th

Magnetic flux density B

9

coat

10

ground

11

container space

12

first insulation ring

12 '

second insulation ring

12 '

third insulation ring

12 '' '

fourth insulation ring

13

Lorentz force F _θ

14

cooling device

15

electrical supply lines

16

electrical supply line

17 '

first Anodes Switching Regulators

17 ''

second Anodes Switching Regulators

17 '' '

third Anodes Switching Regulators

17 ^IV

fourth Anodes Switching Regulators

18

container axis

19

paraxial directed solidification front

20

first Control / regulating device

21

inflow

22

outflow

23

thermal Insulation mantle

24

second investment

25

second container

26

second coat

27

second ground

28

second container space

29

opening area

30

first insulation ring

30 '

second insulation ring

30 ''

third insulation ring

31

second Lorentz force F _θ

32

coat comprehensive cooling device

33 '

first Cathodes Switching Regulators

33 ''

second Cathodes Switching Regulators

33 '' '

third Cathodes Switching Regulators

34

radial directed solidification front

35

second Control / regulating device

36

second inflow

37

second outflow

38

thermal insulation

40

investment

41

Mold container

42

ring anode

43

cooling ring

44

solenoid

45

Entry cathode

46

magnetic field

47

Lorentz force F _θ

48

swamp

49

congealing mass

50

Kokillenbehälterausgang

51

power supply

52

meridional turbulence

53

insulating tube

54

flow direction

55

surface

56

supply line

57

supply line

58

Solenoid supply line

59

inflow

60

outflow

61

Katodenstromverlauf

62

first Area

63

second Area

64

third Area

65

fourth Area

66

first edge

67

second edge

H

container height

_he

Solidification front height

j

current density

B

Magnetic flux density

I

electricity

I ₀

Cathode current before the start of solidification at time t ₀

t

Time

Claims (18)

A plant for the controlled solidification of melts of electrically conductive media in a container with cathode and anode and a magnetic coil surrounding the electrodes, wherein an electric current j flowing through the medium and a magnetic flux density B generated by the magnetic coil intersect, characterized in that it contains - a container ( 3 ), in whose container space the medium ( 2 ), - a floor ( 10 ) associated annular cathode ( 4 ) and several in the mantle ( 9 ) spaced apart annular partial anodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ), - in each case between the cathode ( 4 ) and the partial anodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ) and between the partial anodes ( 5 ' . 5 '' 5 ''' . 5 ^IV ) self-contained isolation rings ( 12 . 12 ' . 12 '' . 12 ''' ), - the magnetic coil ( 6 ), which radially the jacket ( 9 ) and whose magnetic flux density B ( 8th ) the ground ( 10 ) and the medium ( 2 ), wherein at least mutually perpendicular components of current j ( 7 ' . 7 '' . 7 ''' . 7 ^IV ) and magnetic flux density B ( 8th ) an azimuthal medium rotation generating Lorentz force F ( 13 ), - one with the ground ( 10 ) connected cooling device ( 14 ), - electrical supply lines ( 15 . 16 ) for the cathode ( 4 ) and the partial anodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ) as well as for the magnetic coil ( 6 ) and - anode current regulator ( 17 ' . 17 '' . 17 ''' . 17 ^IV ) for the partial anodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ) for the controlled circuit of the ground parallel to the container axis ( 18 ) progressive solidification front ( 19 ), wherein the anode current regulator ( 17 ' . 17 '' . 17 ''' . 17 ^IV ) with a power supply control device ( 20 ) keep in touch. Plant according to claim 1, characterized in that the bottom-side cooling device ( 14 ) with an inflow ( 21 ) and an outflow ( 22 ) is provided for a temperature-controlled coolant. Plant according to claim 1 or 2, characterized in that the container casing ( 9 ) a comprehensive insulation protection jacket ( 23 ) having. Plant for the controlled solidification of melts of electrically conductive media in containers with cathode and anode and a magnetic coil surrounding the electrodes, wherein an electrical current j flowing through the medium and a magnetic flux density B generated by the magnetic coil intersect, characterized in that it contains a container ( 25 ), in whose container space ( 28 ) the medium ( 2 ), - one coat ( 26 ), in the opening area ( 29 ), annular anode ( 5 ) and several in the ground ( 27 ) spaced apart annular Teilkatoden ( 4 ''' 4 '' . 4 ' ), - in each case between the anode ( 5 ) and the partial cathodes ( 4 ''' . 4 '' . 4 ' ) and between the partial cathodes ( 4 ''' . 4 '' . 4 ' ) self-contained isolation rings ( 30 . 30 ' . 30 '' ), - the magnetic coil ( 6 ), which radially the jacket ( 26 ) and whose magnetic flux density B ( 8th ) the ground ( 27 ) and the medium ( 2 ), wherein at least mutually perpendicular components of current j ( 7 ^IV . 7 ^v . 7 ^VI ) and magnetic flux density B ( 8th ) an azimuthal medium rotation generating Lorentz force F ( 31 ), - one with the jacket ( 26 ) connected cooling device ( 32 ), - electrical supply lines ( 15 . 16 ) for the partial cathodes ( 4 ''' . 4 '' . 4 ' ), the anode ( 5 ) as well as for the magnetic coil ( 6 ) and - cathode current regulator ( 33 ''' . 33 '' . 33 ' ) for the partial cathodes ( 4 ''' . 4 '' . 4 ' ) to the controlled circuit of the radially from the jacket ( 26 ) out to the container axis ( 18 ) directed progressive solidification front ( 34 ), wherein the cathode current regulator ( 33 ''' . 33 '' . 33 ' ) with a power supply control device ( 35 ) keep in touch. Plant according to claim 4, characterized in that the jacket-surrounding cooling device ( 32 ) with an inflow ( 36 ) and an outflow ( 37 ) is provided for a temperature-controlled coolant. Installation according to claim 4 or 5, characterized in that the container bottom ( 27 ) a bottom insulation protection ( 38 ) having. Plant according to at least one of the preceding claims, characterized in that the sub-electrodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ; 4 ''' . 4 '' . 4 ' ) with a control device ( 20 . 35 ), whose current regulator ( 17 . 33 ) are formed in terms of hardware and / or programming, each subelectrode ( 5 ' . 5 '' . 5 ''' . 5 ^IV ; 4 ''' . 4 '' . 4 ' ) a current regulator ( 17 . 33 ) assigned. Plant according to at least one of the preceding claims, characterized in that with the current regulators ( 17 . 33 ) locally different current densities j and different flow conditions in the electrically conductive melt ( 2 ) are adjustable. Plant according to at least one of the preceding claims, characterized in that the sub-electrodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ; 4 ''' . 4 '' . 4 ' ) in the containers ( 3 . 25 ) at least as the solidification front ( 19 . 34 ) are formed switched off. Plant according to at least one of the preceding claims, characterized in that detector circuits are provided, each with the partial anodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ) or partial cathodes ( 4 ''' . 4 '' . 4 ' ) and indicate the position of the solidification front ( 19 ; 34 ) and the signals to power switch, preferably in the electrode-assigned current regulators ( 17 . 33 ), wherein the sub-electrodes ( 5 ' . 5 '' . 5 ''' . 5 ^IV ; 4 ''' . 4 '' . 4 ' ) are switched off when the flowing stream j no longer for stirring the electrically conductive liquid medium ( 2 ) contributes. Method for controlling the plant according to at least one of claims 1 to 3 or 4 to 10, characterized in that the forming solidification front ( 19 ; 34 ) closest i-th partial electrode ( 5 '; 4 ' ) is turned off in the event that the following is detected: On the adjacent, the solidification front ( 19 . 34 ) further (i + 1) -th partial electrode ( 5 ''; 4 '' ) takes place in each case a current drop ΔI _{i + 1} in the time .DELTA.t with

what can be considered an indication and it is recognized that the solidification front ( 19 ; 34 ) of the i-th partial electrode ( 5 '; 4 ' ), where Δt - the time interval of the current detection; ΔI - current differences between the time intervals of current detection; i - the serial number (') of the i-th partial electrode ( 5 '; 4 ' ), which is not yet contacted by the solidification front and has not yet been switched off, and wherein the respective i-numbering (') from the bottom upwards for the floor cooling system and from the wall radially to the z-tank axis ( 18 ) directed for the jacket cooling system. Process according to claim 11, characterized in that the solidification front ( 19 ; 34 ) closest i-th partial electrode ( 5 '; 4 ' ) is turned off in the event that the following is simultaneously detected: a) In the time Δt there is a momentary current jump ΔI _i ^{t + Δt} on the ith subelectrode ( 5 '; 4 ' ), which is still on, with

and b) on the adjacent (i + 1) th partial electrode ( 5 ''; 4 '' ) takes place in each case a current drop ΔI _{i + 1} in the time .DELTA.t with

which can be regarded as a display and it is recognized that the solidification front of the i-th partial electrode ( 5 '; 4 ' ), where Δt - the time interval of current detection; ΔI - the current differences between the time intervals of current detection; i - the serial number (') of the i-th partial electrode ( 5 '; 4 ' ), of the solidification front ( 19 ; 34 ) is not yet contacted and is not switched off, and wherein the respective i-numbering (') from the bottom upwards for the floor cooling system and from the wall radially to the z-container axis ( 18 ) directed for the jacket cooling system. Process according to Claim 11 or 12, characterized in that the nth partial electrode (farthest from the cooling) ( 5 ^IV ; 4 ''' ) eg the uppermost part of the tank ( 5 ^IV ) or the partial ( 4 ''' ), which is assigned to the floor center, is switched off only in the case when the entire melt ( 2 ) in the container ( 3 ; 25 ) is solidified, the criterion for a constant current with

is. Plant for the controlled solidification of melts of electrically conductive media during continuous casting, characterized in that for the controlled solidification of stirrable melts ( 2 ) conductive liquid media in containers with cathode and anode and a magnetic coil surrounding the electrodes ( 44 ) through the melt ( 2 ) and a magnetic field B generated by the magnetic coil intersect, wherein it contains a mold container ( 41 ) - a container wall-inherent ring anode ( 42 ) and - a cooling ring ( 43 ) in the form of a jacket cooling zone for carrying out the solidification of the melt ( 2 ), - one the ring anode ( 42 ) and the cooling ring ( 43 ) surrounding kokillenbehälterexterne magnetic coil ( 44 ) and - an entry cathode ( 45 ) in the middle in the open mold container ( 41 ) is arranged and from above into the melt ( 2 ), the entry cathode ( 45 ) and the ring anode ( 42 ) are arranged such that the generated current j ( 61 ) perpendicular to the magnetic field B ( 46 ), which is connected to the magnetic coil ( 44 ), the resulting Lorentz force F _θ ( 47 ) is directed in the azimuthal direction and the liquid region of the melt ( 2 ) above the swamp ( 48 ) emotional. Installation according to claim 13 and / or 14, characterized in that the entry cathode ( 45 ) represents a nozzle cathode comprising an insulator tube ( 53 ) is arranged upstream, through which the melt to be cast into a strand ( 2 ) in the direction ( 54 ) to the nozzle cathode ( 45 ) flows, wherein the nozzle cathode ( 45 ) during continuous casting below the surface ( 55 ) of the melt ( 2 ) is located. Plant according to claim 13 to 15, characterized in that the power supply unit ( 51 ) via the insulated supply line ( 56 ) with the nozzle cathode ( 45 ), via the supply line ( 57 ) with the ring anode ( 42 ) and via the supply line ( 58 ) with the magnetic coil ( 44 ) connected is. Installation according to one of the preceding claims, characterized in that the cooling ring ( 43 ) each have a coolant inflow ( 59 ) and a coolant flow ( 60 ) having. Installation according to one of the preceding claims, characterized in that the cooling ring ( 43 ) is designed as a ring anode and at the same time as a mold container.