JPH08108264A - Device for controlling fluidity of molten metal - Google Patents

Abstract

PURPOSE: To uniformly obtain the cleanness on the inner surface of a casting mold and to promote the float-up of gas bubble by equalizing the polarity of a magnetic pole end surface of a second set of linear motor to the polarity of the magnetic pole end surface of a first set of linear motor. CONSTITUTION: The linear motors 3F, 3L are formed with the combination of plural slot electric magnet cores 4F, 4L and electric coils inserted into the cores. The linear motors 3F, 3L generate driving force in the direction along the inner walls 1 to the molten metal MM, AC current, by which the faced end surfaces of the electric magnet cores 4F, 4L of the linear motors become the same polarity, is conducted in the electric coils. The faced electric magnet cores 4F and 4L generate repulsion magnetic field, and the permeated depth of magnetic flux to the molten steel MM is small and the magnetic flux concentrates near the inner surfaces of the mold sides. By this constitution, the inner surfaces of the mold side are cleaned and the entrapment of powder into the side surfaces of the molten steel is prevented. Further, the entrapment of gas bubble into the side surfaces of the molten steel (mold surfaces) is prevented and the clean steel slab surfaces can be obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flow control device for adjusting the flow rate of molten metal in a mold, and more particularly, the direction of the superficial flow of molten metal in a continuous casting mold is kept constant in the horizontal direction. And a flow control device for maintaining a constant direction.

[0002]

2. Description of the Related Art For example, in continuous casting, molten steel is poured into a mold from a tundish, and in the mold, the molten steel is drawn out while gradually cooling from the wall surface of the mold. If the temperatures on the wall surfaces of the mold having the same height are not uniform, surface cracks and shell breakages are likely to occur. In order to improve this, conventionally, using a linear motor, the molten steel is flow-driven in the mold in parallel with the upper surface thereof along the wall surface of the mold (for example, JP-A-1-228).
645).

Although the flow driving of molten steel presented in Japanese Patent Application Laid-Open No. 1-228645 has some effect, the circulating flow along the wall surface of the mold is disturbed by the flow of molten steel flowing into the tundish through the injection nozzle. . For this type of flow drive, a linear motor type electromagnet in which an electric coil is wound around each of a plurality of magnetic poles arranged along the long side of the mold is used, and the electric coil is for every three phases. Bundled in
It is connected to each phase of a three-phase power supply with a 120 ° phase shift in a bundled unit, and the voltage and / or frequency of the three-phase power supply is adjusted by an inverter or a cycloconverter.
The required driving force and speed are obtained.

Molten steel flows from the nozzle into the mold in two directions. That is, the molten steel flows toward the left and right short pieces and slightly toward the depth direction of the molten steel to generate a molten steel flow (protruding flow) in the short side direction of the mold and in the depth direction of the molten steel, which is the short side of the mold. Some flow upward and the other downward (depth direction), and the molten steel flow flowing upward generates a superficial flow from the short piece toward the nozzle. When molten steel is flowing out from the nozzle symmetrically toward both short sides at the same angle and the same flow velocity, the surface flow on the left and right of the nozzle is substantially symmetrical, but the two-way symmetry collapses due to nozzle clogging, etc. Alternatively, if the outflow direction of the molten steel is biased toward the long side, the symmetry of the left and right surface layer flows with respect to the nozzle is broken, and a swirling flow is generated, so that the powder on the meniscus is likely to be caught. On the other hand, when molten steel changes into a solid, gas (bubbles) such as CO is generated. In addition, if the molten steel stays on a part of the inner surface of the mold, the powder is likely to remain on the molten steel, and further seizure that causes breakout is likely to occur. In order to prevent these, it is preferable to form a stable rectification on the surface layer.

Therefore, conventionally, a pair of linear motors are arranged along the long side of the mold so as to sandwich the molten steel flow flowing from the nozzle into the mold or the surface layer flow generated thereby outside the mold wall. The electromagnetic drive force is applied to the molten steel by these to generate a stable static flow along the inner wall of the mold in the surface layer of the molten steel. When the circulating flow along the inner wall of the mold in the surface layer stably flows at a constant speed, the floating of the bubbles is promoted, the powder entrainment in the molten steel disappears, and the inner surface of the mold near the surface layer is wiped clean and the molten steel does not stay. .

[0006]

As described above, a strong electromagnetic force is required to generate a stable molten steel flow (surface flow) at a constant speed when the projecting flow from the injection nozzle is taken into consideration. Conventionally, a power source may be required for each linear motor, and in order to deepen the magnetic flux penetration from the linear motor to the molten steel, the number of poles of the linear motor is as small as about 2 and it is applied to the linear motor. The frequency of the three-phase alternating current is also 1
It is as low as ~ 2Hz.

However, without correcting the strength and / or imbalance of the protruding flow from the injection nozzle, only the surface flow on the surface of the meniscus is controlled, and the distribution (direction and strength) of the surface flow is determined as a static flow. When it is desired to stabilize near, the large electromagnetic force is not necessary, but it is more important to concentrate the electromagnetic force near the inner wall of the mold. In other words, in the electromagnetic force generated by the flow control device used for electromagnetically driving molten steel for the projecting flow from the injection nozzle, in the case of only stabilizing the superficial flow, the magnetic flux to the molten steel is The penetration depth (the y-direction component of the magnetic field parallel to the short side) is excessively large, and the electromagnetic force acts deeper in the molten steel than the surface of the meniscus, so that there is a risk of entraining the powder.

An object of the present invention is to promote the floating of bubbles on the surface of a meniscus, avoid the inclusion of powder in molten steel, and / or wipe the inner surface of the mold near the surface layer more effectively and with a small electric power. To do.

[0009]

[MEANS FOR SOLVING THE PROBLEMS] A molten metal flow control device of the present invention is a mold side (5F, 5L, 6R, which surrounds a molten metal (MM).
A first set of electromagnet cores having a plurality of slots arranged along one side (5F) of the 6L) so as to face the molten steel in the mold.
(4F) and a plurality of electric coils (CF1 to CF24) inserted in a plurality of slots, the first set of linear motors
(3F); The first set of electromagnet cores (4F) with the molten steel in the mold in between along the other side (5L) facing the one side (5F)
A combination of a second set of electromagnet cores (4L) having a plurality of slots and a plurality of electric coils (CL1 to CL24) inserted in the plurality of slots, which are arranged so as to face the magnetic pole end faces of The second set of linear motors (3L); and the electric coils (CF1 to CF24) of the first set of linear motors (3F) are applied with an AC voltage of a predetermined phase difference, and the second set of linear motors (3L) ) Electric coil (CL1 to CL24) with a predetermined phase difference, the magnetic pole end faces of the second set of linear motors (3L) facing the polarities of the magnetic pole end faces of the first set of linear motors (3F) Energizing means (VC, SW1 to SW4) for applying the alternating voltage to make the polarities of the same polarity;
Is provided.

In order to facilitate understanding, the reference numerals of corresponding elements in the embodiments described later are added in parentheses for reference.

[0011]

In the present invention, the linear motor (3F, 3L) is arranged along one side of the mold side (1) surrounding the molten metal (MM).
Is an electromagnet core (4F, 4L) having a plurality of slots and a plurality of electric coils (CF1 to 4L) inserted in the plurality of slots.
24, CL1 to 24). Linear motor (3F, 3L)
Generates a driving force with respect to the molten metal (MM) in a direction along one side of the mold side (1).

At this time, each electric coil (CF1 to 24, CL1 to 24)
The energizing means (VC, SW1 to SW4) energizes each of the above with an alternating current in which the opposite end faces of the electromagnet cores (4F and 4L) of the linear motor have the same polarity. This allows the opposing electromagnet core (4F
And 4L) generate magnetic fields that repel each other, and the penetration depth of the magnetic flux into the molten steel (MM) is small, and the magnetic flux concentrates near the inner surface of the mold side (5F, 5L). As a result, the inner surface of the mold side (5F, 5L) is wiped to prevent the powder from being drawn in (engaged) on the molten steel side surface (mold surface), and moreover, near the inner surface of the mold side (5F, 5L). The air bubbles are promoted to float, the air bubbles are prevented from being drawn (engaged) into the molten steel side surface (mold surface), and a clean steel surface is obtained.

Compared with the conventional case, the magnetic flux is concentrated on the molten steel side surface (mold surface) rather than the inside of the molten steel, and since deep penetration of the magnetic flux into the molten steel is not required, it is necessary to connect to each electric coil (CF1 to 24, CL1 to 24). Power can be supplied from a single power supply.

Other objects and features of the present invention will become apparent from the following description of embodiments with reference to the drawings.

[0015]

FIG. 1 shows the appearance of an embodiment of the present invention. Molten steel MM is injected into a space surrounded by the inner wall 1 of the continuous casting mold through a pouring nozzle 22 (not shown), and the meniscus (surface) of the molten steel MM is covered with the powder PW. The inner wall 1 of the mold is cooled by the cooling water flowing in the water box 2, the molten steel MM gradually solidifies from the surface in contact with the mold, and the slab SB is continuously withdrawn, but the molten steel is poured into the inner wall 1 of the mold. Therefore, there is always molten steel MM in the mold. Two linear motors 3F and 3L are provided at a position of the meniscus level (height direction z) of the molten steel MM, and these apply an electromagnetic force to a portion (surface layer area) immediately below the meniscus of the molten steel MM.

In FIG. 2, the inner wall 1 shown in FIG.
The cross section (2a-2a line enlarged cross section) horizontally broken at the electromagnet cores 4F and 4L portions of the magnets 3F and 3L is shown, and FIG. 3 shows the 3a-3a line enlarged cross section of FIG.

Referring to FIGS. 1 and 2, the inner wall 1 of the mold is composed of long sides 5F and 5L facing each other and short sides 6R and 6L facing each other, and each side is a copper plate 7F, 7L.
8R, 8L, non-magnetic stainless steel plate 9F, 9L, 10
It is a backing of R and 10L. In this example,
The electromagnet cores 4F, 4L of the linear motors 3F, 3L are slightly longer than the effective lengths of the mold long sides 5F, 5L (the lengths in the x direction in contact with the molten steel MM), and the depths (the lengths in the y direction) in the entire lengths thereof.
24 of the same slot are cut at a predetermined pitch. Electric coils CF1 to CF24 are attached to the respective slots of the electromagnet core 4F of the linear motor 3F.
Similarly, electric coils CL1 to CL24 are attached to the respective slots of the electromagnet core 4L of the linear motor 3L, and the linear motors 3F and 3L are arranged in the x direction along the long sides 5F and 5L with which the molten steel MM is in contact. Is intended to be applied to the molten steel MM.

In this embodiment, the linear motors 3F and 3L are used.
The cores 4F and 4L are slightly longer than the effective lengths of the mold long sides 5F and 7L (the lengths in the x direction with which the molten steel MM contacts), and 24 slots are cut at a predetermined pitch in their entire lengths. In each slot of the core 4F of the linear motor 3F,
# 1 group electric coils CF1 to CF12 and # 2
Group electric coils CF13 to CF24 are mounted. Further, the electric coils CL1 to CL12 of the # 3 group and the electric coils CL13 to CL24 of the # 4 group are mounted in each slot of the core 4L of the linear motor 3L.

FIG. 4 shows a system diagram showing the overall construction of an embodiment of the present invention, and FIG. 5 shows the connection in the group of all the electric coils shown in FIG. Linear motors 3F, 3
Each electric coil group # 1, # 2, # 3, # 4 of L is
The changeover switches SW1, SW2, SW3, and SW4 are connected to a power supply circuit VC that generates a three-phase AC voltage. The connection shown in FIG. 5 has four poles (N = 4), and three-phase alternating current (M = 3) is applied to the electric coil. For example, the electric coils CF1 to C of the # 1 group of the linear motor 3F
F12 is u, u, V, V, w, in this order in FIG.
It is represented by w, U, U, v, v, W, W. And "U" is the positive phase energization of the U phase of the three-phase AC (as it is energization)
"U" represents the reverse phase energization of the U phase (180 degrees out of phase from the U phase), and the U phase is applied to the winding start end of the electric coil "U", while the electric coil "U" means that the U phase is applied to the end of the winding. Similarly, “V” is the positive-phase energization of V-phase of three-phase AC, and “v” is V
"W" represents the W-phase positive phase energization of three-phase AC, and "w" represents the W-phase anti-phase energization. Terminals U1, V1 and W1 shown in FIG. 5 are power supply connection terminals of the electric coils CF1 to CF12 of the # 1 group of the linear motor 3F, and terminals U2, V2 and W2 are # 2 of the linear motor 3F. Power supply connection terminals for the electric coils CF13 to CF24 of the group, and terminals U3, V3 and W3 are electric coils CL1 to CL12 of the # 3 group of the linear motor 3L.
The power supply connection terminals of, and terminals U4, V4 and W4 are
Electric coil CF13 of # 4 group of linear motor 3L
~ CF24 power supply connection terminals. The opposing coils of the linear motor 3F and the linear motor 3L are connected so as to have the same pole (the magnetic pole end faces have the same polarity).

Each of the electric coils CF1 to CF12 of the # 1 group of the linear motor 3L has a switching relay switch SW1.
Is connected to a power supply circuit VC that generates a three-phase AC voltage. As shown in FIG. 4, the switch SW1 is
The relay coil is energized (switch this to SW1: O
N)), the electric coils CF1 to CF1 from the power supply circuit VC.
The power supply terminal U1 of the CF12 is supplied with the U phase of the three-phase AC, the power supply terminal V1 is supplied with the V phase of the three-phase AC, and the power supply terminal W1 is supplied with the W-phase of the three-phase AC. , The electric coils CF1 to CF12 of the # 1 group are
As shown by the solid arrow in FIG. 4, a moving magnetic field is applied to the molten steel MM, which is directed toward the paper surface and to the right in the x direction, whereby a thrust force in that direction is applied to the molten steel MM. The state in which the power supply to the relay coil of the switch SW1 is cut off (this is set to SW1: O
(Referred to as FF), the connection between the power supply terminals V1 and W1 is exchanged for the V-phase output and the W-phase output of the power supply circuit VC, and the W-phase of the three-phase AC is supplied to the power supply terminal V1.
Since the V phase of the three-phase AC is supplied to the power supply terminal W1,
Each of the electric coils CF1 to CF12 of one group is made of molten steel M.
A moving magnetic field that is opposite to the solid arrow shown in FIG.
The thrust in that direction is applied to.

Similarly, each of the electric coils CF13 to CF24 of the # 2 group of the linear motor 3F generates a three-phase AC voltage via the switching relay switch SW2.
It is connected to C. SW2: When ON, power supply circuit VC
The power supply terminal U2 of the electric coils CF13 to CF24 is supplied with a three-phase AC U phase, the power supply terminal V2 is supplied with a three-phase AC V phase, and the power supply terminal W2 is supplied with a three-phase AC W phase. As a result, the electric coils CF13 to CF24 of the # 2 group apply a moving magnetic field to the molten steel MM toward the paper surface and to the right in the x direction as shown by the solid line arrow in FIG. Thrust in that direction is applied to MM. Then, at SW2: OFF, the connection between the power supply terminals V2 and W2 is exchanged with respect to the V-phase output and the W-phase output of the power supply circuit VC, and the W-phase of the three-phase AC is supplied to the power supply terminal V2. Since the V phase of the three-phase AC is supplied to the power supply terminal W2, the electric coils CF13 to C of the # 2 group are supplied.
F24 gives a moving magnetic field to the molten steel MM, which is opposite to the solid line arrow shown in FIG. 4, and is directed to the left in the x direction toward the paper surface, whereby a thrust force in that direction is applied to the molten steel MM.

On the other hand, each of the electric coils CL1 to CL12 of the # 3 group of the linear motor 3L is connected to the power supply circuit VC for generating a three-phase AC voltage via the changeover relay switch SW3, and the # 4 group of the linear motor 3L. The respective electric coils CL13 to CL24 of the switching relay switch SW4
Is connected to a power supply circuit VC that generates a three-phase AC voltage. Switches SW3 and SW4 are SW1 and SW
In the case of SW3: ON, the U phase, V phase, and W phase of the three-phase AC are supplied from the power supply circuit VC to the power supply terminals U3, V3, and W3, respectively, with respect to the molten steel MM. A moving magnetic field to the right in the x direction indicated by a solid arrow in FIGS. 4 and 5 is applied, and thereby a thrust force in that direction is applied to the molten steel MM. When SW3 is OFF, U-phase, W-phase, and V-phase of three-phase AC from the power supply circuit VC are supplied to the power supply terminals U3, V3, and W3, respectively.
The phases are supplied, and a moving magnetic field to the left in the x direction opposite to the direction indicated by the solid arrow in FIGS. 4 and 5 is applied to the molten steel MM, whereby a thrust in that direction is applied to the molten steel MM. Also, SW
4: When ON, power supply terminals U4, V4, W4,
The U-phase, V-phase, and W-phase of three-phase alternating current are supplied from the power supply circuit VC, and a moving magnetic field to the right in the x direction indicated by a solid arrow in FIGS. 4 and 5 is applied to the molten steel MM. Directional thrust is applied. When SW4: OFF, power supply terminal U
4, V4, W4 are respectively supplied with U-phase, W-phase, and V-phase of three-phase AC from the power supply circuit VC, and the molten steel MM is fed to the molten steel MM as shown in FIG.
Further, a moving magnetic field to the left in the x direction opposite to the direction indicated by the solid line arrow in FIG. 5 is applied, whereby a thrust force in that direction is applied to the molten steel MM.

FIG. 6 shows the configuration of a power supply circuit VC for supplying a three-phase alternating current to the electric coils CF1 to CF24 of the linear motor 3F and the electric coils CL1 to CL24 of the linear motor 3L. A thyristor bridge 12 for DC rectification is connected to a three-phase AC power supply (three-phase power line) 11, and its output (pulsating current) is an inductor 13 and a capacitor 14.
Is smoothed by. The smoothed DC voltage is applied to the power transistor bridge 15 for forming the three-phase AC, and the U-phase of the three-phase AC output by the power transistor bridge 15 is turned ON / OFF via the switching relay switches SW1 to SW4 shown in FIG. Regardless of this, it is supplied to the power supply connection terminals U1 to U4. When the switches SW1 to SW4 are ON, the V phase of the three-phase AC is applied to the power supply connection terminals V1 to V4, and the W phase is applied to the power supply connection terminals W1 to W4. Further, when the switches SW1 to SW4 are off, the W phase of the three-phase alternating current is supplied to the power supply connection terminals V1 to V4, V
The phases are applied to the power supply connection terminals W1 to W4.

Each electric coil CF1 of the linear motor 3F
Each electric coil CL of CF24 and linear motor 3L
1 to CL24: predetermined coil voltage command value Vc
Is given to the phase angle α calculator 16, and the phase angle α calculator 16
Calculates a conduction phase angle α (thyristor trigger-phase angle) corresponding to the command value Vc, and gives a signal representing this to the gate driver 17. The gate driver 17 starts phase counting of the thyristor of each phase from the zero-cross point of each phase, and triggers conduction at the phase angle α. As a result, the direct current voltage indicated by the command value Vc is applied to the transistor bridge 15. On the other hand, the three-phase signal generator 18 uses the frequency designated by the frequency command value fc (3.3H in this embodiment).
The constant voltage three-phase alternating current signal of z) is generated and given to the comparator 19. The triangular wave generator 21 also supplies a constant voltage triangular wave having a frequency of 3 kHz to the comparator 19. The comparator 19 is U
When the phase signal level is positive, it is the triangular wave generator 1
8 is a high level H (transistor on) when the level is higher than the level of the triangular wave, and a low level L (transistor off) when the level is lower than the level of the triangular wave.
180 degrees) (to U-phase positive voltage output transistor)
To the gate driver 20, and when the level of the U-phase signal is negative, it is a high level H when it is below the level of the triangular wave provided by the triangular wave generator 21, and when it exceeds the level of the triangular wave, it is a low level L signal. In the negative section of the U phase (180-3
60 degrees) (to the U-phase negative voltage output transistor) to the gate driver 20. The same applies to the V-phase signal and the W-phase signal. The gate driver 20 turns on and off each transistor of the transistor bridge 15 in response to the signals addressed to these phases, positive and negative sections.

As a result, the U-phase voltage of three-phase AC is output to the power supply connection terminals U1 to U4, and the power supply connection terminals V1 to V4.
4 and the power supply connection terminals W1 to W4, each switch SW1
V phase voltage of 3 phase AC or W by ON / OFF of ~ 4
Phase voltages are output, the levels of these voltages are determined by the coil voltage command value Vc, and the frequency of the three-phase voltage is 3.3 Hz in this embodiment based on the frequency command value fc. That is, of the voltage value designated by the coil voltage command value Vc,
A three-phase AC voltage of 3.3 Hz is applied to the electric coils CF1 to CF of the linear motors 3F and 3L shown in FIGS.
24 and CL1 to CL24.

As described above, in this embodiment, a three-phase alternating current of 3.3 Hz is applied to the linear motors 3F and 3L having a four-pole configuration, and the linear motors 3F and 3L cause molten steel MM in the inner wall 1 of the mold. Is applied with a thrust in the direction along the inner wall 1 of the mold (x direction).

In FIG. 7A, when the switches SW1 and SW4 are ON and the switches SW2 and SW3 are OFF, the electric coil is energized 3
Shows the phase output of the phase alternating current and the direction of the thrust applied to the molten steel MM,
In (b), the switches SW1 and SW4 are OF
F indicates the phase output of the three-phase alternating current supplied to the electric coil and the direction of the thrust applied to the molten steel MM when the switches SW2 and SW3 are ON. Both (a) and (b) are opposed coils (electric coil group #
1 and # 4 and electric coil groups # 2 and # 3) have the same polarity, and (a) shows a force applied to the molten steel MM from the left and right in the direction along the inner wall 1 of the mold toward the center of the mold. In (b), a force is applied to the molten steel MM from the center of the mold to the left and right in the direction along the inner wall 1 of the mold.

In FIG. 8, the switches SW1 to SW4 are shown in FIG.
Molten steel MM when all are energized (ON) as shown in
The electromagnetic force distribution on the surface of is shown. As can be understood from this, the electromagnetic force is concentrated on the inner wall surface of the mold, the vertical force component (y-direction component) is small, and powder entrainment on the molten steel surface portion is prevented without considering the protruding flow from the injection nozzle, It can be seen that it is convenient to consider only helping the floating of bubbles. Also, since the AC frequency is as high as 3.3 Hz, the penetration depth of the magnetic flux into the molten steel is small, the vortex in the center of the molten steel (position farther from the mold wall) is weakened, and the possibility of powder entrainment is low and bubbles rise. Is promoted at the same time
Since the two linear motors are driven by a common power source,
Only one power supply is needed and low power requirements.

Since the thrust direction (pattern) can be selected by the switches SW1 to SW4, the powder is less involved and the thrust direction (pattern) is suitable for promoting the floating of bubbles. Can be set appropriately.

[0030]

According to the present invention, since the opposing linear motors generate an electromagnetic force of the same pole, the vertical force component (y-direction component) becomes small, the vortex flow is weak, and the powder can be wound accordingly. In addition, the electromagnetic force at the outer edges of adjacent vortices is continuous and the y-direction component is extremely small near the inner surface of the long side of the mold, so to speak, x of the electromagnetic force over the entire long side (x direction). A directional component is uniform, a constant direction (x direction) and a constant velocity creeping flow are produced, the wipe on the inner surface of the mold becomes uniform, and the floating of bubbles is promoted.

[Brief description of drawings]

FIG. 1 is a perspective view showing an external appearance of one embodiment of the present invention and a central longitudinal section.

FIG. 2 shows the electromagnet cores 4F and 4L shown in FIG.
It is an expanded sectional view fractured horizontally in a line.

FIG. 3 is an enlarged sectional view taken along line 3a-3a of FIG.

FIG. 4 is a block diagram showing an overall configuration of the present invention.

5 is a cross-sectional view corresponding to FIG. 2 showing connection and phase division of the electric coil shown in FIG.

FIG. 6 is a schematic view of an electric coil of each linear motor shown in FIG.
It is an electric circuit diagram which shows the structure of the power supply circuit VC which applies a phase alternating voltage.

FIG. 7 (a) shows switches SW2 and S shown in FIG.
Phase division of electric coil and molten steel M when W3 is turned off
2 shows the direction of flow of M, and FIG. 2B shows the direction of the driving force applied by the linear motor to the phase division of the electric coil and the molten steel MM when the switches SW1 and SW4 shown in FIG. 4 are turned off. It is a considerable sectional view.

FIG. 8 shows that all the switches SW1 to SW4 shown in FIG.
It is a top view which shows N and the electromagnetic force distribution which appears on the molten steel MM surface when a 3-phase alternating current voltage of 3.3 Hz is applied to a linear motor.

[Explanation of symbols]

1: Inner wall of mold 2: Water box 3F, 3L: Linear motor PW: Powder MM: Molten steel SB: Cast slab 4F, 4L: Electromagnetic core 5F, 5L: Long side 6R, 6L: Short side 7F, 7L: Copper plate 8R, 8L: Copper plate 9F, 9L: Non-magnetic stainless steel plate 10R, 10L: Non-magnetic stainless steel plate CF1 to CF24, CL1 to CL24: Electric coil U1, V1, W1: Power supply connection terminals for electric coil CF1 to CF12 U2, V2, W2: Power supply connection terminals for electric coils CF13 to CF24 U3, V3, W3: Power supply connection terminals for electric coils CL1 to CL12 U4, V4, W4: Power supply connection terminals for electric coils CL13 to CL24 SW1, SW2, SW3, SW4: Switching relays Switch VC: Power supply circuit 22: Pouring nozzle outlet

Claims (2)

[Claims] 1. A first set of electromagnet cores having a plurality of slots, which are arranged to face the molten steel in the mold along one side of the mold surrounding the molten metal, and are inserted into the plurality of slots. A first set of linear motors composed of a combination of a plurality of electric coils; facing the magnetic pole end surface of the first set of electromagnet cores with the molten steel in the mold interposed along the other side facing the one side. A second set of linear motors, each of which is a combination of a second set of electromagnet cores having a plurality of slots and a plurality of electric coils inserted in the plurality of slots; and a first set. AC voltage of a predetermined phase difference is applied to the electric coil of the linear motor of No. 2, and the polarity of the magnetic pole end face of the first set of the linear motor of the predetermined phase difference is applied to the electric coil of the second set of the linear motor. Opposing magnetic poles of the second set of linear motors A flow control device for molten metal, comprising: an energizing means for applying an AC voltage, the end faces of which have the same polarity. 2. A first group and a second group of energizing means respectively provide a phase difference of an AC voltage applied to an electric coil for reversing the direction of a moving magnetic field exerted on molten metal in a mold by each linear motor. The molten metal flow control device according to claim 1, further comprising switching means for switching.