JP3210811B2 - Flow controller for molten metal - Google Patents

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, to controlling the direction of the surface flow of molten metal in a continuous casting mold as horizontally as possible. Also, the present invention relates to a flow control device for setting a direction.

[0002]

2. Description of the Related Art In continuous casting, for example, molten steel is poured into a mold from a tundish, and the molten steel is drawn from the mold wall while being gradually cooled. If the temperatures on the mold wall surfaces at the same height are not uniform, surface cracks and shell ruptures are likely to occur. In order to improve this, conventionally, a molten steel is flow-driven in a mold in parallel with the upper surface thereof along a mold wall by using a linear motor (for example, see Japanese Patent Application Laid-Open No. 1-228).
645).

Although the flow driving of molten steel disclosed in Japanese Patent Application Laid-Open No. 1-228645 has a certain effect, the circulating flow along the mold wall surface is disturbed by the flow of molten steel flowing into the tundish through the injection nozzle. . For this type of flow driving, 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. Bundled into
Each phase of the three-phase power supply having a phase shift of 120 ° is connected 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.

[0004] Molten steel flows into the mold from the nozzle in two directions. In other words, the molten steel flows toward the left and right short pieces and slightly in the depth direction of the molten steel, and a molten steel flow (protruding flow) occurs in the short side direction of the mold and slightly in the depth direction of the molten steel, which hits the short side of the mold. Some flows upward and others downward (in the depth direction), and the molten steel flow flowing upward produces a surface flow from the short piece toward the nozzle. When molten steel is flowing symmetrically from the nozzle toward both short sides at the same angle and the same flow velocity, the left and right surface flows are approximately symmetric with respect to the nozzle, but the two-way symmetry is lost due to nozzle clogging and the like. When the outflow direction of the molten steel is deviated to the long side, the symmetry of the left and right surface flows with respect to the nozzle is broken, a swirling flow is generated, and the powder on the meniscus is easily entrained. On the other hand, when the molten steel changes to a solid, a gas (bubbles) such as CO is generated. In addition, if the molten steel stays in a part of the inner surface of the mold, the powder tends to remain in the molten steel, and it is easy to cause seizure which causes breakout. In order to prevent these, it is preferable to form a stable rectification on the surface layer.

Therefore, conventionally, a pair of linear motors is arranged along the long side of the mold so that the molten steel flow flowing out of the nozzle into the mold or the surface flow generated thereby is sandwiched outside the mold wall. By these means, an electromagnetic driving force is applied to the molten steel to generate a stable static flow along the inner wall of the mold on the surface layer of the molten steel. When the circulating flow along the inner wall of the mold flows stably at a constant speed on the surface layer, the floating of bubbles is promoted, powder is not entrained in the molten steel, the inner surface of the mold near the surface layer is wiped clean, and the stagnation of the molten steel is eliminated .

[0006]

As described above, a strong electromagnetic force is required to generate a stable molten steel flow (surface flow) at a constant speed in consideration of the projecting flow from the injection nozzle. Conventionally, a power supply is required for each linear motor, and the number of poles of the linear motor is as small as about 2 poles in order to deepen the magnetic flux from the linear motor to the molten steel. Frequency of the three-phase alternating current
It is as low as about 2 Hz.

However, without correcting the strength and / or imbalance of the protruding flow from the injection nozzle, only the surface flow on the meniscus surface is controlled, and the distribution (direction and intensity) of the surface flow is determined by static flow. In order to stabilize the temperature near the mold, a large electromagnetic force is not required, but it is more important to concentrate the electromagnetic force near the inner wall of the mold. In other words, the electromagnetic force generated by the flow control device used for the electromagnetic drive of molten steel for the projecting flow from the injection nozzle can be used to stabilize only the superficial flow. Since the penetration depth (the y-direction component of the magnetic field parallel to the short side) is excessive and the electromagnetic force acts deeper into the molten steel than the meniscus surface, there is a danger that the powder may be involved.

SUMMARY OF THE INVENTION It is an object of the present invention to promote the floating of air bubbles on the surface of a meniscus, avoid powder entrainment in molten steel, and / or wipe the inner surface of a mold near the surface layer more effectively and with low power. I do.

[0009]

According to the present invention, there is provided a molten metal flow control apparatus, comprising: a mold side (5F, 5L, 6R,
6L) A first set of electromagnet cores having a plurality of slots arranged along one side (5F) of the molten steel in the mold.
(4F) and the first set of linear motors consisting of a combination of multiple electric coils (CF1 to CF24) inserted in multiple slots
(3F); along another side (5L) opposite to the one side (5F), opposed to the magnetic pole end face of the first set of electromagnet cores (4F) with molten steel in the mold therebetween. Also, a second set of linear motors (3L) composed of 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. ); And applying an AC voltage having a predetermined phase difference to the electric coils (CF1 to CF24) of the first set of linear motors (3F), and applying the electric coils (CL1 to CL24) of the second set of linear motors (3L). The first set of linear motors having a predetermined phase difference
The polarity of the pole tip surface of the second set of linear motors (3L) opposite to the polarity of the pole tip surface of the motor (3F) is the same.
Applying an AC voltage, energization means (VC, SW1 to SW4); a flow control apparatus for molten metal comprising, the energization hand
The stages (VC, SW1 to SW4) are where each linear motor is
Electric coil for reversing the direction of the moving magnetic field
Switching means (S) for switching the phase difference of the AC voltage applied to the
W1 to SW4).

[0010] In the parentheses, for easy understanding, reference numerals of corresponding elements in the embodiments described later are added for reference.

[0011]

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

At this time, each electric coil (CF1-24, CL1-24)
In each of these, the energizing means (VC, SW1 to SW4) applies an alternating current in which the opposed 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 repulsive magnetic fields, respectively, so that the penetration depth of the magnetic flux into the molten steel (MM) is small, and the magnetic flux is concentrated 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 into the side surface (mold surface) of the molten steel (mold surface). Of the air bubbles in the molten steel is promoted, the air bubbles are prevented from being drawn into (entangled with) the molten steel side surface (mold surface), and a clean steel single surface can be obtained.

Compared with the prior art, since the magnetic flux concentrates on the molten steel side surface (mold surface) rather than inside the molten steel, and does not require deep penetration of the magnetic flux into the molten steel, each electric coil (CF1-24, CL1-24)
Can be energized by one power supply. Switching hand
Thrust direction (pattern) can be selected by step (SW1 to SW4)
Less powder entrainment and air bubbles rise
Proper thrust direction (pattern) suitable for acceleration
Can.

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 powder PW. The inner wall 1 of the mold is cooled by the cooling water flowing into the water box 2, and the molten steel MM is gradually solidified from the surface in contact with the mold and the slab SB is continuously drawn out, but 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 the position of the meniscus level (height direction z) of the molten steel MM, and these apply an electromagnetic force to a portion (surface area) immediately below the meniscus of the molten steel MM.

FIG. 2 shows that the inner wall 1 shown in FIG.
FIG. 3 shows a cross section (an enlarged cross section taken along the line 2a-2a) of the electromagnet cores 4F and 4L of the rotors 3F and 3L, and FIG. 3 shows an enlarged cross section taken along the line 3a-3a in FIG.

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

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

FIG. 4 is a system diagram showing the overall configuration of one embodiment of the present invention, and FIG. 5 shows connections in the group of all the electric coils shown in FIG. Linear motor 3F, 3
Each of the electric coil groups # 1, # 2, # 3, and # 4 of L
It is connected to a power supply circuit VC that generates a three-phase AC voltage via changeover switches SW1, SW2, SW3, and SW4. The connection shown in FIG. 5 has four poles (N = 4), and supplies a three-phase alternating current (M = 3) to the electric coil. For example, the electric coils CF1 to CF of the # 1 group of the linear motor 3F
F12, u, u, V, V, w,
They are represented as w, U, U, v, v, W, W. And "U" is 3-phase AC U-phase positive-phase energization (current energization as it is).
And "u" represents reverse-phase energization of the U phase (energization 180 degrees out of phase with the U phase), and the electric coil "U" is applied with the U phase at the winding start end. "U" means that the U phase is applied to the end of the winding. Similarly, “V” indicates V-phase positive-phase energization of three-phase AC, and “v” indicates V-phase.
“W” indicates the positive phase energization of the W phase of the three-phase AC, and “w” indicates the negative phase energization of the W phase. Terminals U1, V1 and W1 shown in FIG. 5 are power supply connection terminals of 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. Terminals U3, V3 and W3 are power supply connection terminals of the electric coils CF13 to CF24 of the group, and the terminals U3, V3 and W3 are electric coils CL1 to CL12 of the # 3 group of the linear motor 3L.
Terminals U4, V4 and W4 are
Linear motor 3L # 4 group electric coil CF13
電源 CF24 are 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 polarity (the pole faces are of the same polarity).

The electric coils CF1 to CF12 of the # 1 group of the linear motor 3L are connected to 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
A state where the relay coil is energized (this is called SW1: O
N), the power supply circuit VC supplies the electric coils CF1 to CF1.
The power terminal U1 of the CF 12 is supplied with the U-phase of three-phase AC, the power terminal V1 is supplied with the V-phase of three-phase AC, and the power terminal W1 is supplied with the W-phase of three-phase AC. , # 1 group of the electric coils CF1 to CF12,
As shown by the solid arrow in FIG. 4, a moving magnetic field is applied to the molten steel MM toward the paper surface and to the right in the x direction, whereby a thrust in the direction is applied to the molten steel MM. A state where the power supply to the relay coil of the switch SW1 is cut off (this is referred to as SW1: O
FF), the connection between the power supply terminals V1 and W1 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 three-phase AC is supplied to the power supply terminal V1.
Since the V phase of the three-phase alternating current is supplied to the power supply terminal W1,
Each group of electric coils CF1 to CF12 is made of molten steel M
M is given a moving magnetic field opposite to the solid line arrow shown in FIG.
, A thrust in the direction is applied.

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

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

FIG. 6 shows a configuration of a power supply circuit VC for supplying 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 supplied to an inductor 13 and a capacitor 14.
Is smoothed. The smoothed DC voltage is applied to a power transistor bridge 15 for forming a three-phase AC, and the U-phase of the three-phase AC output from the power transistor bridge 15 is turned on / off via switching relay switches SW1 to SW4 shown in FIG. Is supplied to the power 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 connection terminals V1 to V4, and the W phase is applied to the power connection terminals W1 to W4. When the switches SW1 to SW4 are OFF, the W phase of the three-phase AC is connected to the power connection terminals V1 to V4,
The phases are applied to the power connection terminals W1 to W4.

Each electric coil CF1 of the linear motor 3F
Each electric coil CL of CF24 and linear motor 3L
Predetermined coil voltage command value Vc given to 1 to CL24
Is supplied to the phase angle α calculator 16 and the phase angle α calculator 16
Calculates the conduction phase angle α (thyristor trigger-phase angle) corresponding to the command value Vc, and supplies a signal representing this to the gate driver 17. The gate driver 17 starts the 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 DC voltage indicated by the command value Vc is applied to the transistor bridge 15. On the other hand, the three-phase signal generator 18 outputs the frequency specified by the frequency command value fc (3.3H in this embodiment).
z), a constant-voltage three-phase AC signal is generated and supplied to the comparator 19. A triangular wave generator 21 also provides a constant voltage triangular wave having a frequency of 3 kHz to the comparator 19. The comparator 19 is U
When the level of the phase signal is positive, it is the triangular wave generator 1
8 is a high level H (transistor on) when the level is greater than or equal to the triangular wave level, and a low level L (transistor off) when the level is less than the triangular level.
180 degrees) (to U-phase positive voltage output transistor)
When the level of the U-phase signal is negative, the signal is at a high level H when the level is below the level of the triangular wave provided by the triangular wave generator 21 and at a low level L when the level exceeds the level of the triangular wave. In the negative interval of the U phase (180-3
60 degrees) (to the U-phase negative voltage output transistor). The same applies to the V-phase signal and the W-phase signal. The gate driver 20 turns on and off the transistors of the transistor bridge 15 in response to the signals for each phase, positive and negative sections.

Thus, the three-phase AC U-phase voltage is output to the power supply connection terminals U1 to U4, and the power supply connection terminals V1 to V4 are output.
4 and the power connection terminals W1 to W4
V-phase voltage of three-phase AC or W by ON / OFF of ~ 4
The phase voltages are output, the levels of these voltages are determined by the coil voltage command value Vc, and the frequency of this three-phase voltage is 3.3 Hz according to the frequency command value fc in this embodiment. That is, of the voltage value specified by the coil voltage command value Vc,
The 3.3 Hz three-phase AC voltage is applied to each of 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, 3L having a four-pole configuration, and the linear motors 3F, 3L cause the molten steel MM in the mold inner wall 1 to be applied. , A thrust in the direction (x direction) along the mold inner wall 1 is applied.

FIG. 7A shows a state where the electric coil is energized when the switches SW1 and SW4 are ON and the switches SW2 and SW3 are OFF.
The phase output of the phase alternating current and the direction of the thrust given to the molten steel MM are shown,
In (b), the switches SW1 and SW4 are turned off.
F indicates the phase output of the three-phase alternating current supplied to the electric coil when the switches SW2 and SW3 are ON, and the direction of the thrust applied to the molten steel MM. In both (a) and (b), opposing coils (electric coil group #
1 and # 4 and the 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 mold inner wall 1 toward the center of the mold. In (b), a force is applied to the molten steel MM from the center of the mold toward the left and right in the direction along the mold inner wall 1.

FIG. 8 shows switches SW1 to SW4 in FIG.
Molten steel MM when all energized (ON) as shown in
3 shows an electromagnetic force distribution on the surface of the solid state. 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 is prevented without considering the protruding flow from the injection nozzle, It can be seen that it is convenient to consider only helping the air bubbles to float. In addition, 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 at the center of the molten steel (at a position farther from the mold wall) is weakened, and the possibility of powder entrainment is low, and bubbles rise. Is promoted,
Since two linear motors are driven by a common power supply,
Only one power source is required and the required power is low.

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

[0030]

According to the present invention, since the opposed linear motors generate the same electromagnetic force, the vertical force component (y-direction component) is reduced, the eddy current is weak, and the entrainment of the powder is correspondingly possible. In addition, near the inner surface of the long side of the mold, the electromagnetic force of the outer edge of the adjacent vortex is continuous, and the component in the y direction is extremely small, so to say, the electromagnetic force in the x direction over the entire length of the long side (x direction). A uniform surface, a constant direction (x-direction) and a constant velocity creeping flow are provided, so that the wiping of the inner surface of the mold becomes uniform and the floating of bubbles is promoted. Low entrainment of powder, air bubbles
A thrust direction suitable for promoting the upward can be appropriately set.

[Brief description of the drawings]

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

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

FIG. 3 is an enlarged sectional view taken along line 3a-3a in FIG. 2;

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

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

FIG. 6 shows an electric coil of each linear motor shown in FIG.
FIG. 3 is an electric circuit diagram showing a configuration of a power supply circuit VC for applying a phase AC voltage.

FIG. 7A shows switches SW2 and S shown in FIG.
Phase separation of electric coil and molten steel M when W3 is turned off
FIG. 2B shows a direction in which the linear motor M flows, and FIG. 2B shows a direction of the driving force applied by the linear motor to the molten steel MM when the switches SW1 and SW4 shown in FIG. It is a considerable sectional view.

FIG. 8 shows that all switches SW1 to SW4 shown in FIG.
FIG. 6 is a plan view showing an electromagnetic force distribution appearing on the surface of molten steel MM when a 3.3 Hz three-phase AC voltage is applied to the linear motor.

[Explanation of symbols]

1: inner wall of mold 2: water box 3F, 3L: linear motor PW: powder MM: molten steel SB: cast piece 4F, 4L: electromagnet core 5F, 5L: long side 6R, 6L: short side 7F, 7L: copper plate 8R, 8L: Copper plate 9F, 9L: Non-magnetic stainless plate 10R, 10L: Non-magnetic stainless plate CF1 to CF24, CL1 to CL24: Electric coil U1, V1, W1: Power connection terminals of electric coil CF1 to CF12 U2, V2, W2: Power connection terminals of electric coils CF13 to CF24 U3, V3, W3: Power connection terminals of electric coils CL1 to CL12 U4, V4, W4: Power connection terminals of electric coils CL13 to CL24 SW1, SW2, SW3, SW4: Switching relay Switch VC: Power supply circuit 22: Pouring nozzle outlet

────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-5-38559 (JP, A) JP-A-5-23804 (JP, A) JP-A-63-183761 (JP, A) JP-A-4- 200849 (JP, A) JP-A-7-241649 (JP, A) JP-A-7-241654 (JP, A) JP-A-7-246444 (JP, A) JP-A 8-90169 (JP, A) JP-A-6-182518 (JP, A) Japanese Utility Model Application Sho 57-56548 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) B22D 11/04 311 B22D 11/115 B22D 27 / 02

Claims (1)

(57) [Claims] A first set of electromagnet cores having a plurality of slots disposed along one side of a mold surrounding the molten metal and facing the molten steel in the mold, and inserted into the plurality of slots. A first set of linear motors comprising a combination of a plurality of electric coils; along another side opposing the one side, facing a pole tip surface of the first set of electromagnet cores with molten steel in a mold therebetween; A second set of linear motors comprising 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; An AC voltage having a predetermined phase difference is applied to the electric coil of the linear motor, and the AC voltage of the predetermined phase difference is applied to the electric coil of the second set of linear motors with respect to the polarity of the magnetic pole end surface of the first set of linear motors. Magnetic poles of the second set of linear motors And polarity of the same polarity face, applying an AC voltage, energization means; a flow control apparatus for molten metal comprising, said energizing means, the linear motor to the molten metal in the mold
Electric coil to reverse the direction of the moving magnetic field
Includes switching means for switching the phase difference of the applied AC voltage
A flow control device for molten metal, comprising: