JP2022508566A - Control of flow velocity in continuous casting - Google Patents

Abstract

The device (1) for controlling the magnetic flux in the mold (2) for continuous casting of metal is provided with at least two associated first magnetic coils (4) located on one side of the mold. One first front core (3) and at least two second having a related second magnetic coil (6) substantially aligned with the first front core and located on opposite sides of the mold. The front core (5) of 2 and the second front core are connected to the first front core, and the first front core is connected to the second front core, or the second front core is connected to the first front core. An external magnetic loop (7,8,9) that allows unidirectional magnetic flux to pass through the mold and a control interface (14) that allows independent control of the two subsets of the first magnetic coil. And.

Description

The present disclosure relates to the field of continuous metal casting, and in particular, proposes an apparatus for controlling the flow velocity in a thin slab casting machine.

Stability control is essential in the process of high speed continuous thin slab casting. The high productivity thin slab casting machine of the prior art can have a throughput of 8 tons or more per minute. In this scenario, the inlet flow rate as the molten steel enters the mold from the immersion nozzle (SEN) is fast, a strong turbulent effect occurs at the top of the strands, and the flow pattern is unstable, variable and time-varying. With the risk. Reducing these effects is important for obtaining uniform and constant thermal and flow conditions for the fluid steel to solidify uniformly in the mold.

In today's continuous casting machines, slab production often diversifies by grade and size. To accommodate these different casting machine outputs, the operation of the thin slab casting machine dynamically changes depending on the width, casting speed, SEN type, SEN immersion, overheating, mold funnel type and the like. A difficult aspect of the process is to provide an equivalent solidification environment that is independent of casting machine parameters, with conditions favorable for uniform solidification. Particularly present in high speed thin slab casting machines is the risk of excessive meniscus flow velocity, fluctuations, turbulence and biased flow, which can cause mold powder entrainment or initial shell solidification fluctuations. There is.

The electromagnetic brake (EMBR) not only brakes the flow of molten steel in the mold, but also controls the current flowing through the brake to adjust the braking force to an appropriate level according to the inflow speed of steel. Therefore, in a thin slab casting machine, a great alternative for dynamically canceling such a phenomenon that can cause quality deterioration is provided.

Conventional deterministic (or open-loop) EMBR control applies different currents to the EMBR under different casting conditions. Appropriate current settings are usually found by testing and numerical and physical modeling to assess steel quality and process stability. Not only are these methods cumbersome, time consuming and costly, they also work on a large scale and lack the sharpness to handle local and special events.

European Patent No. 2633928 is an attempt to improve EMBR control, i.e., by placing multiple independently controllable magnetic brakes in different zones of the casting die. This allows the operator a certain degree of freedom to cancel the left-right asymmetry or depth gradient in the flow of molten metal. However, due to the configuration of the magnetic poles, the magnetic brake can only apply a magnetic field in which the direction of at least one local magnetic field in the mold is opposite to the direction of the other local magnetic fields in the mold. In other words, the braking device according to European Patent No. 2633928, which has one left braking zone and one right braking zone, operates in modes such as (+,-) mode, (-, +) mode. It is possible, but it does not work, for example, in (+, +) mode or (+, 0) mode.

One object of the present disclosure is to propose a flow velocity control device that enables more flexible, flexible and / or more adaptable flow rate control in a mold for continuous casting of metal. This object is achieved by the present invention as defined by the independent claims.

In a first aspect, the device for controlling the flow velocity in the mold for continuous casting of metal is at least two first with a related first magnetic coil located on one side of the mold. And at least two second front cores with an associated second magnetic coil, substantially aligned with the first front core and located on opposite sides of the mold, and a second. By connecting the front core and the first front core, a magnetic flux in one direction passes from the first front core to the second front core or from the second front core to the first front core. It has an external magnetic loop that enables it. According to one embodiment, the flow rate controller further comprises a control interface that allows independent control of the two subsets of the first magnetic coil.

The combination of an external magnetic loop and a control interface that allows a portion of the first magnetic coil to be controlled independently of the other first magnetic coil allows the flow velocity controller to have different strengths in different regions of the mold. It can supply magnetic flux in one direction. The unidirectional magnetic flux is the magnetic flux directed from the mold side close to the first front core to the mold side close to the second front core at any place unless it is locally zero, or any of them. In terms of location, it is the magnetic flux directed from the mold side near the second front core to the mold side near the first front core. The presence of an external magnetic loop makes it possible to generate a unidirectional magnetic flux, but (+,-) or (-, +) type magnetic fluxes can also be applied and the net magnetic flux is zero (eg, for example). It can be (if the left and right sizes are equal) or non-zero (eg, if the left and right sizes are different). The presence of an external magnetic loop is such that the direction of at least one local magnetic field in the mold faces the direction of the other local magnetic field in the mold, as described in European Patent No. 2633928. The restriction is lifted.

In one embodiment, the control interface allows independent control of two or more subsets of the second magnetic coil. This is in addition to the independent control of two or more subsets of the first magnetic coil enabled by the control interface. The effect of the controllability of the second magnetic coil is that the geometry and / or local intensity of the magnetic flux can be controlled more accurately.

The subset of the first magnetic coil and / or the subset of the second magnetic coil may be located at different positions with respect to the lateral direction of the mold. For example, in an embodiment where the flow rate controller comprises one left side and one right side first front core and one left side and one right side second front core, two related left side magnetic coils. Can be controlled independently of the two related right magnetic coils. This allows for more precise adjustment of the applied magnetic flux with respect to the lateral direction, thereby allowing more precise control of the flow velocity including the flow geometry.

In a variant, the flow velocity controller can include two left and two right first front cores and two left and two right second front cores, two left first. Front cores can be placed at different heights to better cover the vertical direction of the mold. Similarly, each of the first front core on the right side, the second front core on the left side and the second front core on the right side can be arranged at different heights. According to this variant, the magnetic coils associated with the two left first front cores can be controlled independently of the magnetic coils associated with the two right first front cores. Further, (i) between the magnetic coils associated with the first front core on the upper left and lower left sides, (ii) between the magnetic coils associated with the second front core on the upper left and lower left sides, (iii) between the upper right side and the magnetic coils. Between the magnetic coils associated with the first front core on the lower right side, (iv) between the magnetic coils associated with the second front core on the upper right side and the lower right side, and / or (v) the second on the left side of the two. There is optional-not required-control independence between the magnetic coil associated with the two front cores and the magnetic coil associated with the two right-hand second front cores.

In the above embodiments, independent control can be achieved by the fact that the control interface comprises electrical terminals for exciting each subset of magnetic coils. In other words, electrically separated terminals (or terminal pairs) are provided for each subset. Alternatively, if the control interface comprises a processor and is at least partially implemented in software, control independence can be achieved by software instructions to this effect.

In one embodiment, the control interface is adapted to coordinately control the magnetic coils associated with a pair of aligned front cores. For example, the magnetic coil related to the first front core on the left (upper) side and the magnetic coil related to the second front core on the left (upper) side are coordinately controlled. The first front core on the left (upper) side and the second front core on the left (upper) side are the first front core on the left (upper) side and the left (upper) side that are approximately parallel to the lateral direction of the mold. ) Can be aligned in the sense that the axes of symmetry of the second front core on the side are substantially aligned. Coordinated control is understood in the sense that a control signal or exciting current that is substantially equal or proportional is applied to both magnetic coils so that the magnetic fluxes passing through both coils are equal or substantially equal. Should be. This can be achieved by providing a control interface with common electrical terminals (or pairs of terminals) for exciting the magnetic coils of those magnetic coils to be coordinated. Similarly, in the case of a control interface with a processor, coordinated control can be achieved by providing the corresponding software instructions.

In one embodiment, the magnetic coil is controlled based on sensor data related to temperature distribution or temperature gradient in the mold or sensor data related to meniscus characteristics. The sensor data can have spatial resolution with respect to the lateral direction of the mold. That is, the sensor data can include at least one value on the left side and one value on the right side. In embodiments with finer spatial resolution, there may be three or more different sensor data values corresponding to the same number of points or regions distributed along the lateral direction of the mold.

In one embodiment, the first and / or second front core comprises a flux shaping element. This allows the spatially non-uniform magnetic flux to pass through the mold. The flux shaping element can be reconfigurable.

In one embodiment, the external magnetic loop comprises a first and second level core that can be retracted away from the mold to allow for mold replacement or maintenance, and an external yoke. Be prepared. As a result, the second front core reaches the first front core via the second level core, the outer yoke, and the first level core, and the magnetic flux passes laterally through the mold to the second. It provides a magnetic circuit that can create a magnetic field in a virtually closed loop that reaches the front core.

In one embodiment, the flow velocity control device is supported so that it can move independently of the mold. Usually, the mold is attached to the shaking table for smoother casting. Flow control devices that do not benefit from vibration must be mounted on a different support structure than the shaking table. Thereby, the shaking table has a simpler design, is more economical to operate, and can reduce wear and fatigue, as the shaking table requires less weight to support.

A second aspect provides a system for continuous metal casting, comprising a mold, a molten metal supply, and a flow rate control device having the above characteristics. Preferably, the system is a thin slab casting machine.

In general, all terms used in the claims should be construed in accordance with their usual meaning in the art, unless otherwise specified herein. The terms flow velocity control device, electromagnetic braking device, electromagnetic brake (EMBR) and device for short can be used interchangeably in the present disclosure. All references to "elements, instruments, components, means, steps, etc." should be openly construed as referring to at least one example of an element, instrument, component, means, step, etc., unless otherwise stated. be. The steps of any method disclosed herein need not be performed in the exact order in which they are disclosed, unless expressly stated.

Next, as an example, embodiments and embodiments will be described with reference to the accompanying drawings.

It is a partial perspective sectional view of a thin slab casting machine provided with a single magnetic coil on both sides of a casting die. It is a partial perspective sectional view of a thin slab casting machine provided with a single magnetic coil on both sides of a casting die. It is a schematic top view of a thin slab casting machine equipped with an external yoke that cannot independently control the magnetic coils on both sides of the mold. FIG. 3 is a schematic top view of a thin slab casting machine comprising independently controllable left and right magnetic coils on both sides of a mold and two internal yokes arranged such that the directions of the left and right magnetic fields face each other. FIG. 3 is a schematic top view of a thin slab casting machine comprising an independently controllable left and right magnetic coils on both sides of a die and an external yoke according to an embodiment of the present invention. It is a schematic front view of the structure of the magnetic flux shaping element arranged on the front core of a thin slab casting machine. It is a perspective view of the front core of the thin slab casting machine which has the structure of the magnetic flux shaping element. It is a schematic front view of the structure of the magnetic flux shaping element shown in FIG. 7a. In a schematic top view of a thin slab casting machine with independently controllable left and right magnetic coils and an external yoke on either side of a mold showing a processor, control interface and sensor according to an embodiment of the invention. be. It is a perspective view of a casting mold in which a plurality of horizontally arranged optical fibers for sensing the temperature distribution in the mold are present on the wall. It is a figure which shows the velocity distribution v (x) and the meniscus height h with respect to the lateral direction x, and shows the transverse section (lower part) of SEN of a thin slab casting machine, and the transverse section (upper part) which passes through the BB line. ..

Next, aspects of the invention will be described more fully with reference to the accompanying drawings showing specific embodiments of the invention.

However, these embodiments can be embodied in many different forms and should not be construed as limitations, rather these embodiments are complete and complete in the present disclosure and all aspects of the invention. It is provided as an example to fully convey the scope of. Similar reference codes refer to similar elements throughout the description, as summarized in the description of the codes below.

1 and 2 are cross-sectional views of different amounts of opaque objects removed, showing a thin slab casting machine system with a common type of electromagnetic braking device. During operation, the SEN 13 discharges a molten metal such as steel, iron or a non-ferrous alloy into the mold 2. Due to the downward force of gravity of the metal itself and the subsequent weight of the metal above it in the mold 2, the metal moves vertically to reach the cooler region of the mold 2. Therefore, it gradually solidifies (crystallizes) and finally advances from the mold 2 as a continuous slab. The mold 2 can be made of copper, for example, optionally with a lubricated or coated inner surface to adjust friction, and can have a cross section of about 100 mm × 1400 mm, 5.5 m / min. Can be adapted to the casting speed of.

The electromagnetic braking devices shown in FIGS. 1 and 2 have a first front core 3 (visible only in FIG. 2) on the proximal side of the mold 2 and a second front on the distal side of the mold 2. It has a core 5 (visible only in FIG. 2). One magnetic coil 4, 6 surrounds each front core 3, 5, thereby being associated with the front cores 3, 5. An electrical terminal 10 for exciting the magnetic coil 4 on at least the proximal side is shown. The subdivided proximal portions 3.1, 5.1 of the first and second front cores 3, 5 are of cooling medium passages 11.1, 12.1 adapted to remove excess heat. It extends through the corresponding passage to the surface of the mold 2. The electromagnetic braking device further comprises first and second level cores 8 and 9, the first and second level cores 8 and 9 interacting with the front cores 3 and 5 and further closing the magnetic circuit. Interacts with the double-sided magnetic yoke 7 which is useful. The interface of the magnetic circuit may be solid or may include an air gap. The magnetic yoke 7 and the level cores 8 and 9 can be made of a ferromagnetic material such as iron.

The white arrows indicate the direction of the local magnetic flux while the magnetic coils 4 and 6 are excited. Under the action of the excited magnetic coils 4, 6, the metal flow in the mold 2 under the SEN 13 is exposed to a static magnetic field B substantially perpendicular to the flow velocity v. Therefore, the metal has a braking eddy current force F = σ (E + v × B) × B in a direction substantially opposite to the flow velocity v.
Receive. Note that E is a local electric field, and σ is the conductivity in an appropriate unit. The electromagnetic braking devices shown in FIGS. 1 and 2 may not allow independent control of the flow in different lateral positions of the mold 2.

FIG. 3 is a schematic top view of a thin slab casting machine provided with an electromagnetic braking device including an external yoke 7. This thin slab casting machine has the same characteristics as those described with reference to FIGS. 1 and 2. The electromagnetic braking device installed in the thin slab casting machine is provided with a single magnetic coils 4 and 6 on both sides of the mold 2. The magnetic coil is excited according to the signal generated by the connected control interface 14 to provide a magnetic flux similar to that suggested by the solid arrow. The control interface 14 can allow independent control over the two magnetic cores 4, 6, but it is not possible to give different strengths to the lateral magnetic fields on the left and right sides of the mold 2.

FIG. 4 shows the left and right first front cores 3a and 3b related to the left and right first magnetic coils 4a and 4b, and the left and right second front cores 5a related to the left and right second magnetic coils 6a and 6b. , 5b is a top view of a further prior art casting system with an electromagnetic braking device. The magnetic flux is circulated by the first internal magnetic yoke 15 that interacts with the left and right first front cores 3a and 3b and the second internal magnetic yoke 16 that interacts with the left and right second front cores 5a and 5b. Can be done. Since the magnetic flux indicated by the solid arrow is recirculated through the mold 2, as in European Patent No. 2633928, the illustrated electromagnetic braking device has left and right magnetic field directions facing each other. It can only generate such a magnetic field. This is true regardless of the controllability of the magnetic coils 4a, 4b, 6a, 6b.

The present invention proposes a solution for improving the controllability of a magnetic braking field. FIG. 5 shows a thin slab casting machine according to an embodiment of the present invention, which comprises a flow velocity control device 1 including independently controllable left and right magnetic coils 4 and 6 on both sides of a die and an external yoke 7. It is a schematic top view. The control interface 14a on the left side controls the excitation of the magnetic coils 4a, 6a corresponding to the first and second front cores 3a, 5a on the left side. Preferably, the two coils are coordinately controlled in the above sense. The control interface 14b on the right side is arranged to excite the corresponding coil on the right side of the mold 2. The flow velocity control device 1 enables independent control of the magnetic field passing through different lateral positions of the mold 2. The magnetic flux can circulate through an external loop that includes an external yoke 7 instead of the mold 2. For the general characteristics of the flow velocity control device 1 according to the present invention, the above description of the electromagnetic braking device shown in FIGS. 1 to 4 is referred to.

In the modification of the embodiment shown in FIG. 5, the first and second level cores 8 and 9 are also the first level core on the left side, the first level core on the right side, the second level core on the left side and the like. It can be divided into a second level core on the right side. The first left level core then interacts with the first left front core and the like.

FIG. 5 does not explicitly show the support structure of the flow velocity control device 1. The flow velocity control device 1 is preferably supported so as to be able to move independently of the mold 2. Although the mold 2 can be attached to the shaking table, it is preferable that the flow velocity control device 1 is attached to a support structure different from that of the shaking table. In this way, the shaking table supports a lighter load, which simplifies the design of the shaking table.

FIG. 6 is a schematic diagram of the arrangement of the magnetic flux shaping elements arranged in the proximal portions 5.1 and 6.1 of the front cores 5 and 6 of the flow velocity control device 1 in the thin slab casting machine. The filled squares correspond to the portions that extend relatively close to the mold 2, and the empty squares terminate relatively far from the mold 2. Front cores 5 and 6 made of mild steel, iron or other ferromagnetic materials have significantly higher magnetic permeability than air, so the magnetic flux prefers shorter air gaps and concentrates on shorter air gaps. .. Therefore, the local magnetic field becomes relatively stronger with a shorter air gap than with a longer air gap, and as a result, the magnetic flux passing through the mold 2 is more flexibly distributed. This magnetic distribution effect can be even more pronounced if the opposite front cores of the mold 2 have symmetrical flux shaping elements.

Since the configuration of the magnetic flux shaping element can be adapted to the expected flow pattern in consideration of the internal geometry of the mold 2, the characteristics of the SEN 13, the casting speed, and the like, an appropriate braking operation is realized. In some embodiments, the flux shaping element can be reconstructed after deployment to be useful in different casting processes or to incorporate later insights into a given casting process. Reconstructability is guaranteed when the flux shaping element is provided as a plurality of freely positionable magnetic protrusions 17 of the type shown in FIG. 7a. The protrusion 17 can be a rod of iron or another ferromagnetic material that is removable and attached to the recess of each front core. The reconstruction of the flux shaping element is preferably carried out between consecutive continuous casting batches.

In the example shown in FIG. 6, the magnetic flux shaping element makes the magnetic flux relatively strong in the lower portion except for the central portion. In a further example shown in FIG. 7b, the flux shaping element is substantially bowl-shaped corresponding to a position on the mold 2 where stronger braking is expected to be required. Each width of FIGS. 6 and 7b substantially corresponds to the full width of the mold 2. As the perspective views of FIGS. 1 and 2 suggest, the height can correspond to the upper part of the mold 2.

According to one embodiment of the invention, the left and right sides of each of the configurations shown are preferably included in the first (or second) front core of each left and right side with the associated magnetic coil. I want to recall. This provides dynamic left-right controllability, in addition to the option to reconstruct the flux shaping elements between casting batches. In other embodiments with a large number of magnetic coils, the lateral resolution of controllability can be further refined. The patterns shown in FIGS. 6 and 7b are mirror-symmetrical with respect to the left-right direction, but asymmetric patterns can also be used. The distribution of asymmetric braking force resulting from such a pattern may be advantageous for stabilizing the asymmetric casting jet from SEN13.

FIG. 8 is a schematic top view of a thin slab casting machine according to an embodiment of the present invention, which comprises independently controllable left and right magnetic coils 4a, 4b, 6a, 6b on both sides of a die 2 and an external yoke 7. Is. Further, a processor 18, left and right control interfaces 14a and 14b for exciting the magnetic coil, and left and right sensors 19a and 19b for detecting various flow parameters are provided. Flow parameters can include temperature distribution or temperature gradient in mold 2, meniscus height distribution, meniscus velocity, meniscus height variation and / or other meniscus characteristics. The control interfaces 14a and 14b can be connected to a thyristor power converter such as a converter of the DCS family of the applicant, or can be implemented as a thyristor power converter.

Local temperature can be sensed using fiber optic equipment using the methods and devices disclosed in WO 2017/032488, in particular FIGS. 1a, 1b, of WO 2017/032488, See FIGS. 1c, 1d and 2. FIG. 9 of the present disclosure is a perspective view of the upper part of the casting die 2 and the SEN 13. On the wall of mold 2, there is a sensor array with multiple optical fibers (broken lines) that extend horizontally to the lateral openings, which enable the sensing of temperature distribution or temperature gradients with high spatial resolution. do. The resulting sensor data can reveal solidification anomalies and capture the meniscus shape in detail to predict the meniscus flow velocity. Instead of FIG. 9, a vertically arranged optical fiber can also be used. The fully distributed measurement system easily captures both the left and right flow velocities and fluctuations of the SEN 13 and connects to the left and right independent flow control devices 1 of the above type to manage the flow asymmetry. Can be facilitated. High-resolution measurements of temperatures near the meniscus provide sufficient information to control the left and right flow velocities independently. Possible alternative control methods are based on a split set of mold level sensors with individual information about levels and variations from the left and right sides.

FIG. 10 shows the SEN 13 and the resulting inlet velocity distribution v (x). The lower part of the figure is a cross section of SEN13, which is realized as a two-passage fishtail type nozzle. At the top of FIG. 10, there is a cross section along the BB line, and it can be seen that the SEN 13 has a flat cross section that is substantially aligned with the lateral direction of the mold 2. The mold level sensor can allow the velocity distribution v (x) and the meniscus height h to be tracked so that the flow rate controller 1 has an appropriate braking magnetic field for stabilizing the flow. Can be controlled to apply. The magnetic field stabilizes the flow of the molten metal and helps guide the momentum towards the meniscus in a double-roll flow pattern, while minimizing meniscus fluctuations and having a shape suitable for adjusting the local meniscus flow velocity. Can be adapted as such. In one example, for a 100 × 1400 mm mold and a skew inlet velocity condition with ± 50% velocity variation, the left and right magnetic fields applied to equalize the flow velocity of ± 440 mm from the lateral center of the mold 2. It is necessary to make the sizes of the above substantially different by 23%. When this magnetic field is applied, the asymmetry of the meniscus flow is substantially leveled and the peak of the flow velocity is attenuated.

Returning to the description of FIG. 8, the present inventors can perform automatic meniscus flow velocity and asymmetry control by using the left and right independent flow velocity control devices 1 in combination with an online flow rate measuring sensor such as the above-mentioned mold level sensor. I noticed that it is configurable. The closed control loop can be implemented in a processor 18 provided as an industrially suitable computer environment for robust and continuous operation. The control loop can, for example, execute a PID algorithm. As the processor 18, the ABB Ability ™ Optimold Monitor sold by the applicant can be selected.

When the meniscus velocity in the mold is accurately predicted, the closed loop control system controls various control interfaces 14a, 14b of the flow velocity controller 1 to counter the meniscus velocity that is too low or too high. Apply a braking magnetic field or braking electromagnetic field. The control interface 14a on the left side controls the excitation of both the first magnetic coil 4a on the left side and the second magnetic coil 6a on the left side, and the control interface 14b on the right side controls the excitation of both the first magnetic coil 4b on the right side and the second magnetic coil 6a on the right side. It is understood that both excitations with the second magnetic coil 6b of the above are controlled. Similarly, the control loop cooperates with the flow velocity control device 1 to reduce the asymmetry of the flow pattern. For example, the larger flow velocity in one lateral half of the mold 2 can be suppressed by a locally enhanced DC (ie, non-oscillating) magnetic field. Controls can also be performed on the data from the electromagnetic level sensor and high frequency feedback can be used to obtain detailed level and variation information for the probe position. This enables control of the meniscus speed on the upper part of the mold 2 and control of the stability of the meniscus level.

In one embodiment, the control loop comprises two parts, the first part is the determination of EMBR current based on process inputs such as casting speed, SEN geometry, SEN depth, steel grade, mold dimensions and similar process characteristics. It is a department. The decision-making part may rely, in part, on magnetohydrodynamic simulations and / or recorded empirical data. The second part is the dynamic control unit of EMBR. The meniscus level sensors 19 arranged on the left and right sides of the mold 2 can measure the meniscus level and the meniscus fluctuation, take a transient value as an input, and realize dynamic control of the left / right current of the EMBR. The dynamic control unit can include repeated positive and negative adjustments of the initially acquired EMBR current value based on the process input.

In a further embodiment, the processor 18 connected to the control interface 14 is configured to control the magnetic coil based on a numerical simulation of transient hydrodynamics in the mold.

Aspects of the invention have been described primarily with reference to some embodiments. However, as will be readily appreciated by those skilled in the art, embodiments other than those described above are equally possible within the scope of the invention as defined by the appended claims.

1 Device, flow velocity control arrangement, electromagnetic braking device 2 Mold 3 1st front core 3.1 Proximal part of 1st front core 4 Coil related to 1st front core 5 2nd front core 5.1 Proximal part of the second front core 6 Coil related to the second front core 7 External yoke 8 First level core 9 Second level core 10 Electrical terminal 11 First cooling medium passage 12 Second cooling medium Passage 13 Immersion nozzle 14 Control interface 15 First internal yoke 16 Second internal yoke 17 Magnetic protrusion 18 Processor 19 Sensor

Claims (19)

A device (1) for controlling the flow velocity in the mold (2) for continuous casting of metal.
With at least two first front cores (3) with the associated first magnetic coil (4) located on one side of the mold.
With at least two second front cores (5) comprising the associated second magnetic coil (6), substantially aligned with the first front core and located on opposite sides of the mold.
The second front core is connected to the first front core so that the first front core becomes the second front core or the second front core becomes the first front core. An external magnetic loop (7,8,9) that allows the magnetic flux in the direction to pass through the mold, and
In the device (1) provided with
An apparatus (1) comprising a control interface (14) that allows independent control of the two subsets of the first magnetic coil. The device of claim 1, wherein the control interface allows independent control of two subsets of the second magnetic coil. The device according to claim 1 or 2, wherein the subset of the first or second magnetic coil is located at different positions with respect to the lateral direction of the mold. The apparatus according to any one of claims 1 to 3, wherein each of the subsets of the first or second magnetic coil comprises one or more magnetic coils. The device according to any one of claims 1 to 4, wherein the control interface is adapted to coordinately control the magnetic coil associated with a pair of aligned front cores. The device according to any one of claims 1 to 5, wherein the control interface comprises an electrical terminal (10) for exciting the magnetic coil of each subset. The device according to any one of claims 1 to 6, wherein the control interface comprises a processor (18). Further equipped with one or more sensors (19),
The processor of the control interface
It is configured to control the magnetic coil based on sensor data from the sensor representing temperature distribution and / or meniscus height distribution, meniscus velocity, meniscus height variation or another meniscus characteristic in the mold. , The apparatus according to claim 7. The apparatus according to claim 7 or 8, wherein the processor of the control interface is configured to process sensor data having spatial resolution with respect to the lateral direction of the mold. The processor according to any one of claims 7 to 9, wherein the processor of the control interface is configured to control the magnetic coil based on a numerical simulation of transient fluid dynamics in the mold. Device. The apparatus according to any one of claims 1 to 10, wherein the front core includes a magnetic flux shaping element for allowing a spatially non-uniform magnetic flux to pass through the mold. 11. The apparatus according to claim 11, wherein the magnetic flux shaping element is reconfigurable. 12. The apparatus of claim 12, wherein the reconfigurable magnetic flux shaping element comprises a plurality of freely positionable magnetic protrusions (17). The external magnetic loop
The first and second level cores (8, 9) arranged to interact with the first and second front cores, respectively.
With the external yoke (7),
The apparatus according to any one of claims 1 to 13. 14. The device of claim 14, wherein the level core is retractable away from the mold. The device according to any one of claims 1 to 15, further comprising a support structure that allows the device to move independently of the mold. 16. The device of claim 16, wherein none of the parts of the device is supported by a shaking table. A system for continuous metal casting
Mold (2) and
Metal supply unit (13) and
The device according to any one of claims 1 to 17, and the apparatus.
A system equipped with. The system according to claim 18, which is a thin slab casting machine.

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