Molten metal driving device, molten metal stirring system, molten metal conveying system, continuous casting system, and molten metal driving method

Abstract

To obtain big driving force for a molten metal while being low power consumption.SOLUTION: A magnetic field device 2 in a molten metal driving device 1 comprises: iron cores 21 to 25; yokes 31, 32, 33 connecting the iron cores 21 to 25; coils 41a, 41b wound so as to sandwich the yoke 31 into the iron cores 21 to 25; coils 42a, 42b wound so as to sandwich the yoke 32 into the iron cores 21 to 25; and coils 43a, 43b wound so as to sandwich the yoke 33 into the iron cores 21 to 25. The coil 41a and the coil 41b are wound so as to generate a magnetic field H1 going to the yoke 31 when a first phase current flows, the coil 42a and the coil 42b are wound so as to generate a magnetic field H2 going to the yoke 32 when a second phase current flows, and the coil 43a and the coil 43b are wound so as to generate a magnetic field H3 going to the yoke 33 when a third phase current flows.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a molten metal driving device, a molten metal stirring system, a molten metal conveying system, a continuous casting system, and a molten metal driving method.

Background Art

[0002] Conventionally, a molten metal driving device that drives a molten metal of a non-ferrous metal such as aluminum or copper (hereinafter simply referred to as "molten metal" or "molten metal") by electromagnetic force is known. This molten metal driving device includes a magnetic field device that generates a moving magnetic field. When the moving magnetic field travels through the molten metal, eddy currents are generated in the molten metal. An electromagnetic force acts on the molten metal due to these eddy currents, and the molten metal is driven.

[0003] As a molten metal driving device using electromagnetic force, for example, Patent Document 1 describes a molten metal stirring device that generates a moving magnetic field by flowing a three-phase alternating current through a plurality of coils wound around an annular iron core and stirs the molten metal existing inside the annular iron core.

[0004] In addition, a linear motor type molten metal driving device is also widely used. In this method, a plurality of yokes (magnetic poles) are provided in parallel with each other on a single plate-shaped iron core, and coils are wound around the side surfaces of the respective yokes. By energizing the coils wound around the yokes, a magnetic field is radiated from the yokes.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By the way, in order to ensure sufficient driving force for the molten metal, it is required to generate a magnetic field with sufficient intensity in the space where the molten metal to be driven exists.

[0007] As a method of generating a strong magnetic field, it is conceivable to pass a large current through a coil. However, as the current flowing through the coil increases, there is a problem that the power consumption increases and the running cost of the molten metal driving device increases. In addition, the amount of heat generated by the molten metal driving device increases, and a powerful cooling facility such as a water-cooled type is required, so not only the manufacturing cost but also the maintenance cost increases.

[0008] As another method of generating a strong magnetic field, it is conceivable to increase the number of turns of the coil. However, the inductance of the coil increases in proportion to the square of the number of turns of the coil. For this reason, there is a problem that the flow of the alternating current is hindered and a strong magnetic field cannot be obtained. Further, although it is known that the driving force is proportional to the frequency of the alternating current, when the number of turns of the coil is increased and the inductance increases, it becomes difficult to increase the frequency of the alternating current.

[0009] The present invention has been made based on the above technical recognition, and an object thereof is to provide a molten metal driving device, a molten metal stirring system, a molten metal conveying system, a continuous casting system, and a molten metal driving method that can obtain a large driving force while consuming low power.

Means for Solving the Problems

[0010] The molten metal driving device according to an embodiment of the present invention is A molten metal driving device for driving a molten metal, A plurality of iron cores, A first yoke connecting the plurality of iron cores, A second yoke adjacent to the first yoke and connecting the plurality of iron cores, A third yoke adjacent to the second yoke and connecting the plurality of iron cores, First and second coils wound around at least one of the plurality of iron cores so as to sandwich the first yoke, Third and fourth coils wound around at least one of the plurality of iron cores so as to sandwich the second yoke, At least one of the plurality of iron cores is provided with fifth and sixth coils wound so as to sandwich the third yoke. Both the first coil and the second coil are wound so as to generate a magnetic field directed toward the first yoke when a current of the first phase flows, and both the third coil and the fourth coil are wound so as to generate a magnetic field directed toward the second yoke when a current of the second phase flows. Both the fifth coil and the sixth coil are wound so as to generate a magnetic field directed toward the third yoke when a current of the third phase flows.

[0011] Further, in the molten metal driving device, A plurality of sets of the sets of the first to third yokes may be provided on the plurality of iron cores.

[0012] Further, in the molten metal driving device, The thickness of the plurality of iron cores in the direction in which the first to third yokes extend may be smaller than the interval between the plurality of iron cores.

[0013] Further, in the molten metal driving device, The thickness of the plurality of iron cores in the direction in which the first to third yokes extend may be smaller than the thickness in the direction orthogonal to the direction.

[0014] Further, in the molten metal driving device, The first coil and the second coil are connected in series to form a first series coil, the third coil and the fourth coil are connected in series to form a second series coil, and the fifth coil and the sixth coil are connected in series to form a third series coil. The first series coil, the second series coil, and the third series coil may be star-connected. Further, in the molten metal driving device, The molten metal driving device may further include an AC power source that supplies an R-phase current to the first series coil, an S-phase current to the second series coil, and a T-phase current to the third series coil.

[0015] Also, in the molten metal driving device, it further includes a case for housing the plurality of iron cores, the case is provided with an air intake for taking air into the interior of the case and an air outlet for discharging the air in the case to the outside, the air intake and the air outlet may be arranged so as to sandwich the plurality of iron cores.

[0016] Also, in the molten metal driving device, a blower may be connected to the air intake.

[0017] Also, in the molten metal driving device, the plurality of iron cores extend parallel to each other, the first to third yokes may be arranged parallel to each other.

[0018] Also, in the molten metal driving device, the plurality of iron cores extend parallel to each other, the first to third yokes may be bent along the extending direction of the plurality of iron cores.

[0019] Also, in the molten metal driving device, the plurality of iron cores are annular iron cores, and are arranged at intervals so that the central axes of each are coaxial, and the first to third yokes may be arranged inside the annular iron cores.

[0020] The molten metal stirring system according to an embodiment of the present invention includes a furnace for storing molten metal, the molten metal driving device disposed below the furnace, and is characterized by including these.

[0021] The molten metal transfer system according to an embodiment of the present invention includes a trough for transferring molten metal, The molten metal driving device arranged so as to surround at least the lower part of the gutter; It is characterized by including.

[0022] The continuous casting system according to an embodiment of the present invention is A cylindrical mold; The molten metal driving device in which the mold is arranged inside the annular iron core; It is characterized by including.

[0023] The molten metal driving method according to an embodiment of the present invention is A molten metal driving method for driving a molten metal, A step of arranging a molten metal driving device having a magnetic field device so as to be adjacent to a furnace for storing a molten metal, a gutter for transporting the molten metal, or a mold, The magnetic field device includes a plurality of iron cores, a first yoke connecting the plurality of iron cores, a second yoke adjacent to the first yoke and connecting the plurality of iron cores, a third yoke adjacent to the second yoke and connecting the plurality of iron cores, a first and a second coil wound around at least one of the plurality of iron cores so as to sandwich the first yoke, a third and a fourth coil wound around at least one of the plurality of iron cores so as to sandwich the second yoke, and a fifth and a sixth coil wound around at least one of the plurality of iron cores so as to sandwich the third yoke, the step; A step of flowing a current of a first phase through the first coil and the second coil to generate a magnetic field toward the first yoke, flowing a current of a second phase through the third coil and the fourth coil to generate a magnetic field toward the second yoke, and flowing a current of a third phase through the fifth coil and the sixth coil to generate a magnetic field toward the third yoke; It is characterized by including.

Advantages of the Invention

[0024] According to the present invention, it is possible to provide a molten metal driving device, a molten metal stirring system, a molten metal conveying system, a continuous casting system, and a molten metal driving method that can obtain a large driving force while consuming low power.

Brief Description of the Drawings

[0025]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Mode for Carrying Out the Invention

[0026] Hereinafter, embodiments according to the present invention will be described with reference to the drawings. In each figure, components having the same function are denoted by the same reference numerals.

[0027] (First Embodiment) With reference to FIG. 1, a schematic configuration of the molten metal driving device 1 according to the first embodiment will be described. In FIG. 1, coils wound around the iron cores 21 to 25 of the magnetic field device 2 are not shown.

[0028] As shown in FIG. 1, the molten metal driving device 1 includes a magnetic field device 2, a case 5, a terminal box 6, and an AC power supply 7. This molten metal driving device 1 is configured to generate a moving magnetic field by the magnetic field device 2 supplied with three-phase alternating current from the AC power supply 7, and to electromagnetically drive the molten metal by this moving magnetic field.

[0029] The magnetic field device 2, although details will be described later, is configured to generate a moving magnetic field (the repulsive magnetic fields H R , H S , H T ) for driving the molten metal. The magnetic field device 2 is housed in the case 5. For example, the magnetic field device 2 is arranged at a predetermined position in the case 5 by an installation jig or a mounting base (not shown). During the operation of the molten metal driving device 1, the magnetic field device 2 is cooled by the cooling air taken in from the air intake 5a.

[0030] Case 5 is configured to house the magnetic field device 2. The material of the case 5 is not particularly limited, and for example, it is made of a metal such as a refractory material or stainless steel.

[0031] The case 5 has an air intake 5a and an air outlet 5b. The air intake 5a is provided to take in air for cooling the magnetic field device 2 into the case 5. The air outlet 5b is provided to discharge the air inside the case 5 to the outside. In the present embodiment, the air intake 5a is configured as a connection flange of the cold air supply air duct. For this reason, it is possible to connect a blower (not shown) to the air intake 5a and forcibly air-cool the magnetic field device 2.

[0032] As shown in FIG. 1, the air intake 5a and the air outlet 5b are arranged so as to sandwich the cores 21 to 25 along the direction in which the cores 21 to 25 extend. In the present embodiment, the air intake 5a and the air outlet 5b are respectively provided on opposite surfaces of the case 5 (surfaces orthogonal to the direction in which the cores 21 to 25 extend). Thereby, the cooling air taken into the case 5 from the air intake 5a passes between the cores 21 to 25 along the cores 21 to 25 and is then discharged from the air outlet 5b. Since the cooling air is discharged from the air outlet 5b after efficiently cooling the cores 21 to 25 in this way, the cooling efficiency of the magnetic field device 2 can be significantly increased.

[0033] As shown in FIG. 1, the terminal box (terminal box) 6 is provided on the case 5. A terminal post (not shown) is housed in the terminal box 6. The terminal post is electrically connected to the coil of the magnetic field device 2. The terminal box 6 has a wiring inlet 6a for introducing wiring for connecting the terminal post and the AC power supply 7.

[0034] The AC power supply 7 is a three-phase AC power supply and outputs three-phase (R-phase, S-phase, T-phase) AC currents. The AC power supply 7 may be configured to be variable in output current and / or frequency in order to adjust the driving force of the molten metal.

[0035] <Magnetic field device 2> Next, with reference to FIGS. 2 to 4, the configuration and operation of the magnetic field device 2 will be described in detail.

[0036] As shown in FIG. 2, the magnetic field device 2 includes a plurality of cores 21 to 25 arranged at intervals, a plurality of yokes 31 to 36, and a plurality of coils 41a to 46a, 41b to 46b.

[0037] The cores 21 to 25 are made of a ferromagnetic material, for example, composed of silicon steel sheets or carbon steel sheets. From the viewpoint of reducing iron loss, silicon steel sheets are advantageous. However, as will be described later, according to the present embodiment, since the eddy currents generated in the cores 21 to 25 during operation can be reduced more than before, it is possible to use a carbon steel sheet that is advantageous in terms of cost. By using a carbon steel sheet, the weight of the magnetic field device 2 can also be reduced.

[0038] In the present embodiment, as shown in FIG. 2, the cores 21 to 25 are in the form of thin plates or square bars. Note that the shapes of the cores 21 to 25 are not limited to thin plates or square bars, and may be, for example, round bars. Also, the number of cores is not limited to five and may be any number. For example, the number of cores may be determined based on the size of the melting furnace in which the molten metal to be driven is stored.

[0039] As shown in FIG. 2, in the present embodiment, the cores 21 to 25 extend parallel to each other. As a result, the cooling air taken in from the air inlet 5a flows along the cores and through the spaces between the cores, so that the magnetic field device can be cooled extremely efficiently compared to a conventional linear motor type magnetic field device (where the core is a single plate).

[0040] Note that, as shown in FIG. 2, the thickness W of the cores 21 to 25 in the direction in which the yokes 31 to 36 extend (the vertical direction in FIG. 2) may be smaller than the interval D between the cores. Thereby, the cooling efficiency of the cores by the air taken in from the air inlet 5a can be enhanced.

[0041] Further, as shown in FIG. 2, the thickness W of the cores 21 to 25 in the extending direction of the yokes 31 to 36 may be smaller than the thickness T in the direction orthogonal to the said direction. Thereby, the cooling efficiency of the core by the air taken in from the air intake port 5a can be enhanced.

[0042] The yokes 31 to 36 are provided between two coils wound around the cores 21 to 25, and function as magnetic poles when the coils are energized as described later. Each yoke is made of, for example, an alloy such as iron, pure iron (SUY), SS material, or permendur.

[0043] Three yokes form a set. That is, the yokes 31 to 33 constitute the first set, and the yokes 34 to 36 constitute the second set. The yokes 31 and 34 correspond to the R phase, the yokes 32 and 35 correspond to the S phase, and the yokes 33 and 36 correspond to the T phase.

[0044] The yokes 31 to 36 all connect a plurality of cores 21 to 25. In the present embodiment, the yokes 31 to 36 are arranged so as to be orthogonal to the plurality of cores 21 to 25. However, it is not limited to this, and a plurality of yokes may be arranged so as to be obliquely intersecting with a plurality of parallel cores.

[0045] The yokes 31 to 36 are arranged in parallel with each other in the order of the yokes 31, 32, 33, 34, 35, and 36. The yoke 32 is adjacent to the yoke 31, the yoke 33 is adjacent to the yoke 32, the yoke 34 is adjacent to the yoke 33, the yoke 35 is adjacent to the yoke 34, and the yoke 36 is adjacent to the yoke 35.

[0046] In addition, in the present embodiment, the yokes 31 to 36 are directly connected to the cores 21 to 25. However, it is not limited to this, and they may be connected to the cores 21 to 25 via a connection part (not shown). This connection body may be a protrusion provided on the cores 21 to 25, or may be a member separate from the cores and yokes.

[0047] Also, the number of yokes is not limited to six. For example, the number of yokes may be a multiple of three such as nine or twelve. The number of yokes may be determined based on, for example, the size of the melting furnace in which the molten metal to be driven is stored.

[0048] Also, in FIG. 2, the yokes 31 to 36 protrude from the cores 21 and 25 (the cores located at the ends among the plurality of cores arranged in parallel) in a plan view, but it is not limited to this, and they may not protrude.

[0049] Next, the coils wound around the cores 21 to 25 will be described.

[0050] As shown in FIG. 2, a pair of coils are wound around each core so as to sandwich the yoke. For example, around each of the cores 21 to 25, a coil 41a (first coil) and a coil 41b (second coil) are wound so as to sandwich the yoke 31. Similarly, a coil 42a (third coil) and a coil 42b (fourth coil) are wound so as to sandwich the yoke 32, and a coil 43a (fifth coil) and a coil 43b (sixth coil) are wound so as to sandwich the yoke 33. Further, in the present embodiment, a coil 44a (first coil) and a coil 44b (second coil) are wound so as to sandwich the yoke 34, a coil 45a (third coil) and a coil 45b (fourth coil) are wound so as to sandwich the yoke 35, and a coil 46a (fifth coil) and a coil 46b (sixth coil) are wound so as to sandwich the yoke 36.

[0051] In the present embodiment, the number of turns of each coil is the same in order to make the magnetic field strengths generated by the respective coils substantially equal. Note that insulating paper for insulation may be interposed between the coil and the core.

[0052] Coils 41a and 41b are wound around the iron core 21 in opposite directions. Similarly, for iron cores 22 to 25, coils 41a and 41b are wound around them in opposite directions. Coils 41a and 41b of each iron core are connected in series. Therefore, when energized, currents I in opposite directions flow through coils 41a and 41b, generating magnetic fields in opposite directions (see Fig. 4(a)).

[0053] Note that coils 41a and 41b may be wound in the same direction. In this case, coils 41a and 41b are connected in series so that magnetic fields in opposite directions are generated.

[0054] Regarding a pair of coils 42a, 42b, coils 43a, 43b, coils 44a, 44b, coils 45a, 45b, and coils 46a, 46b wound so as to sandwich yokes 32, 33, 34, 35, and 36 respectively, similar to coils 41a, 41b, they are wound so as to generate magnetic fields in opposite directions.

[0055] Both coils 41a and 41b are wound so as to generate a magnetic field H1 (described later) of approximately the same intensity toward yoke 31 when an R-phase current (current of the first phase) flows. Similarly, both coils 44a and 44b are wound so as to generate a magnetic field H1 of approximately the same intensity toward yoke 34 when an R-phase current flows.

[0056] Both coils 42a and 42b are wound so as to generate a magnetic field H2 toward yoke 32 when an S-phase current (current of the second phase) flows. Similarly, both coils 45a and 45b are wound so as to generate a magnetic field H2 toward yoke 35 when an S-phase current flows.

[0057] Both coil 43a and coil 43b are wound so as to generate a magnetic field H3 toward the yoke 33 when a current in the T-phase (current in the third phase) flows. Similarly, both coil 46a and coil 46b are wound so as to generate a magnetic field H3 toward the yoke 36 when a current in the T-phase flows.

[0058] The pair of coils are connected in series. For example, a pair of coils 41a and coil 41b wound around each of the iron cores 21 to 25 are connected in series to form a series coil 41. Similarly, a pair of coils 42a and coil 42b wound around each of the iron cores 21 to 25 are connected in series to form a series coil 42. A pair of coils 43a and coil 43b wound around each of the iron cores 21 to 25 are connected in series to form a series coil 43. A pair of coils 44a and coil 44b wound around each of the iron cores 21 to 25 are connected in series to form a series coil 44. A pair of coils 45a and coil 45b wound around each of the iron cores 21 to 25 are connected in series to form a series coil 45. A pair of coils 46a and coil 46b wound around each of the iron cores 21 to 25 are connected in series to form a series coil 46.

[0059] The series coils 41 to 46 are connected as shown in FIG. 3. That is, the series coil 41 and the series coil 44 are connected in series, the series coil 42 and the series coil 45 are connected in series, and the series coil 43 and the series coil 46 are connected in series. Then, the series-connected series coil 41 and series coil 44, the series-connected series coil 42 and series coil 45, and the series-connected series coil 43 and series coil 46 are star-connected. The series coil 41, the series coil 42, and the series coil 43 are connected to the R-phase terminal, the S-phase terminal, and the T-phase terminal of the AC power supply 7, respectively. Thereby, when the molten metal driving device 1 operates, an R-phase current of the AC power supply 7 flows through the series coils 41 and 44, an S-phase current of the AC power supply 7 flows through the series coils 42 and 45, and a T-phase current of the AC power supply 7 flows through the series coils 43 and 46.

[0060] Note that the connection between the coils is not limited to the above, and the moving magnetic field (HR ,H S ,H T ) may be generated in other connection forms.

[0061] Also, when there is one set of yokes (that is, only three yokes 31 to 33 of the magnetic field device), the series coils 41, 42, and 43 are star-connected.

[0062] In the above magnetic field device 2, for each of the iron cores 21 to 25, a pair of coils was provided so as to sandwich the yoke, but some coils may be omitted. For example, the pair of coils 41a and 41b may be provided only on the iron cores 21, 23, and 25, and the pair of coils 42a and 42b may be provided only on the iron cores 22 and 24.

[0063] <Operation of the magnetic field device 2> Next, with reference to FIGS. 4(a) and 4(b), the operation of the magnetic field device 2 will be described.

[0064] When the R-phase current of the AC power supply 7 flows through the series coil 41, as shown in FIG. 4(a), magnetic fields H1 of substantially the same magnitude and opposite directions are generated in the coils 41a and 41b, respectively. The magnetic field H1 generated in the coil 41a and the magnetic field H1 generated in the coil 41b both go toward the yoke 31. Then, as shown in FIG. 4(b), the two magnetic fields H1 collide and repel in the yoke 31, and the repulsive magnetic field H R generated thereby is radiated from the yoke 31 to the outside. The same applies to the series coil 44 through which the R-phase current flows, and the repulsive magnetic field H R is radiated from the yoke 34 to the outside.

[0065] The same applies to the S phase. That is, when the S-phase current of the AC power supply 7 flows through the series coil 42, magnetic fields H2 of substantially the same magnitude and opposite directions are generated in the coils 42a and 42b. The magnetic field H2 generated in the coil 42a and the magnetic field H2 generated in the coil 42b both go toward the yoke 32, and the two magnetic fields H2 collide and repel in the yoke 32. The repulsive magnetic field H Sis radiated outward from the yoke 32. The same applies to the series coil 45 through which the S-phase current flows, and a repulsive magnetic field H is radiated outward from the yoke 35. S is radiated.

[0066] The same applies to the T-phase. That is, when the T-phase current of the AC power supply 7 flows through the series coil 43, magnetic fields H3 of substantially the same magnitude and opposite directions to each other are generated in the coil 43a and the coil 43b. The magnetic field H3 generated in the coil 43a and the magnetic field H3 generated in the coil 43b both face the yoke 33, and the two magnetic fields H3 collide and repel at the yoke 33. The repulsive magnetic field H T is radiated outward from the yoke 33. The same applies to the series coil 46 through which the T-phase current flows, and a repulsive magnetic field H T is radiated.

[0067] The repulsive magnetic field H R the repulsive magnetic field H S and the repulsive magnetic field H T are repeatedly radiated from the magnetic field device 2 in this order. As a result, the molten metal above the magnetic field device 2 is driven in the direction from the yoke 31 to the yoke 36.

[0068] <Operating Effect of Molten Metal Driving Device 1> As described above, in the molten metal driving device 1, the magnetic field device 2 can radiate a strong repulsive magnetic field. Thereby, the magnetic field device 2 can generate a strong moving magnetic field without passing a large current through the coil or increasing the number of turns of the coil. Therefore, according to the molten metal driving device 1 of the present embodiment, a large driving force can be obtained while consuming low power.

[0069] Furthermore, in the molten metal driving device 1, since each of the cores 21 to 25 is thinner than the core (a single plate-shaped core) of the conventional magnetic field device, eddy currents generated in each of the cores 21 to 25 during energization of the coil can be reduced. For this reason, as the material of the cores 21 to 25, instead of laminating thin silicon steel sheets with low iron loss, general-purpose carbon steel sheets can be used. Therefore, the cost (design cost, material cost, manufacturing cost) of the magnetic field device 2 can be reduced, and the weight of the molten metal driving device 1 can be reduced.

[0070] Furthermore, in the molten metal driving device 1, since the core of the magnetic field device 2 is composed of a plurality of cores 21 to 25 arranged in parallel with intervals therebetween, the surface area of the core of the magnetic field device 2 increases. For this reason, the heat dissipation characteristics can be significantly improved as compared with the conventional case. As a result, in the conventional molten metal stirring device, it was essential to cool the magnetic field device by water cooling, but according to the present embodiment, it is possible to cool the magnetic field device by air cooling. In the case of water cooling, in order to prevent clogging of the pipeline, maintenance costs such as pre-treatment of cooling water such as softening treatment and regular removal of algae are enormous. According to the present embodiment, such maintenance costs can be reduced. In addition, the size of the molten metal driving device 1 can be reduced.

[0071] <Molten Metal Stirring System> As an application example of the molten metal driving device 1 according to the first embodiment, a molten metal stirring system 1100 will be described with reference to FIG. 5.

[0072] The molten metal stirring system 1100 includes a furnace 100 for storing molten metal and a molten metal driving device 1 disposed below the furnace 100. In this example, the molten metal driving device 1 is substantially the same size as the bottom wall of the furnace 100.

[0073] The furnace 100 is, for example, a melting furnace for melting non-ferrous metals such as aluminum or a holding furnace for holding molten metal. The non-ferrous metal may be, for example, Al, Cu, Zn, or an alloy of at least two of these, or an Mg alloy.

[0074] In FIG. 5, a furnace 100 is installed above the molten metal driving device 1. Not limited to this, the molten metal driving device 1 may be installed, for example, in a storage space (not shown) provided below the mounting surface of the furnace 100.

[0075] As shown in FIG. 5, a blower 50 is attached to the air intake 5a of the case 5. The magnetic field device 2 is forcibly cooled by the cooling air sent into the case 5 from the blower 50.

[0076] In the molten metal stirring system 1100, the repulsive magnetic fields H R , H S , H T sequentially radiated by the three-phase alternating current supplied from the AC power supply 7 drive the molten metal M in the furnace 100 along the direction of the arrow in FIG. 5 (that is, the direction from the yoke 31 to the yoke 36). The driven molten metal M hits the side wall of the furnace 100, spreads up, down, left, and right along the side wall, and then diffuses in the direction opposite to the driving direction. As a result, the molten metal M is stirred in the furnace 100.

[0077] Next, with reference to FIG. 6, another application example (molten metal stirring system 1100A) of the molten metal driving device 1 will be described. In this application example, a plurality of molten metal driving devices 1 are arranged below a furnace 100 that is larger than the molten metal driving device 1. In this example, the plurality of molten metal driving devices 1 are arranged along the side wall of the furnace 100 in plan view. Thereby, since the molten metal M in the furnace 100 is driven along the side wall of the furnace 100, it is efficiently stirred in the furnace 100.

[0078] Note that the molten metal driving device 1 may be arranged at the corner of the furnace 100 along the desired stirring direction.

[0079] (Second Embodiment) Next, with reference to FIG. 7, the molten metal driving device 1A according to the second embodiment will be described. FIG. 7 is a partial perspective side view of the molten metal driving device 1A having a magnetic field device 2A. Note that in FIG. 7, the coil wound around the core of the magnetic field device 2A is not shown.

[0080] One of the differences between the first embodiment and the second embodiment is that in the second embodiment, the yokes 31 to 36 are bent in a U shape. Hereinafter, the second embodiment will be described centering on the differences.

[0081] The molten metal driving device 1A includes a magnetic field device 2A, a case 5A, a terminal box 6, and an AC power supply 7. Since the terminal box 6 and the AC power supply 7 are the same as those described in the first embodiment, detailed descriptions thereof are omitted.

[0082] The magnetic field device 2A has the same components as the magnetic field device 2 described in the first embodiment. However, as shown in FIG. 7, in the magnetic field device 2A, the yokes 31 to 36 are bent in a U shape. Specifically, the yokes 31 to 36 are bent along the extending direction of the cores 21 to 25 between the core 21 and the core 22 and between the core 24 and the core 25. Thereby, the magnetic field device 2A has a U shape in side view, and a storage space is formed. In this storage space, a molten metal conveyance path (the trough 200 described later) or the furnace 100 is stored.

[0083] Note that the number of yokes may be increased or decreased according to the conveyance distance of the molten metal (the length of the trough). Also, the number of cores may be increased or decreased according to the width of the trough or the like.

[0084] As shown in FIG. 7, the case 5A is configured to be able to store the magnetic field device 2A in accordance with the shape of the magnetic field device 2A having a U shape in side view. A trough 200 for conveying the molten metal is placed on the upper surface 5s of the case. Note that the material of the case 5A is not particularly limited, and for example, it is made of a metal such as a refractory material or stainless steel.

[0085] Although not shown, air inlets 5a and air outlets 5b are provided at both ends of the case 5A (the tip side and the base end side of the trough 200), respectively. Thereby, similarly to the first embodiment, the cooling air can pass between the cores along the cores 21 to 25, and the cores 21 to 25 can be efficiently cooled.

[0086] FIG. 8 shows a molten metal transfer system 1200 in which a drain pipe 200 is disposed in a storage space defined by a case 5A (magnetic field device 2A). Note that in FIG. 8, the coil wound around the core of the magnetic field device 2A is not shown. FIG. 9 is a side view for explaining the generation of a magnetic field by the magnetic field device 2A of the molten metal driving device 1A. In this figure, a repulsive magnetic field H T is shown being radiated toward the drain pipe 200. Similar to the magnetic field device 2 of the first embodiment, in accordance with the supply of three-phase alternating current, a repulsive magnetic field H R , a repulsive magnetic field H S and a repulsive magnetic field H T are repeatedly radiated from the magnetic field device 2A toward the outside in this order. As a result, the molten metal M in the drain pipe 200 is conveyed in the direction from the yoke 31 to the yoke 36.

[0087] In the present embodiment, the core 21 and the core 25 are disposed along the side wall of the drain pipe 200. For this reason, even when the amount of molten metal to be conveyed is large, a driving force can be applied to the molten metal that is relatively far from the bottom wall of the drain pipe 200, and the molten metal can be efficiently conveyed.

[0088] <Example of use of the molten metal transfer system> FIGS. 10 and 11 show examples of usage forms of the molten metal transfer system 1200. In the example of FIG. 10, the molten metal M in the furnace 100 is poured out from the drain pipe 200, conveyed by the molten metal driving device 1A along the horizontally installed drain pipe 200, and then poured into the container 300.

[0089] In the example of FIG. 11, the tip side of the drain pipe 200 is lifted higher than the base end side, and the drain pipe 200 is installed in a so-called sloped state. A guide plate 210 is provided at the tip of the drain pipe 200. In the case of this example, the molten metal M is conveyed so as to rise in the drain pipe 200 against gravity.

[0090] Furthermore, in the example of FIG. 11, two molten metal transfer systems 1200A and 1200B are connected in series. The molten metal M from the furnace 100 is transferred one step upward by the molten metal transfer system 1200A and sent to the molten metal transfer system 1200B, and the molten metal M is further transferred one step upward by the molten metal transfer system 1200B. Thereby, the molten metal M in the furnace 100 can be moved to the container 300 located at a position two steps higher than the furnace 100.

[0091] Note that three or more molten metal transfer systems 1200 may be connected in series. Thereby, the horizontal transfer distance of the molten metal can be extended, and the transfer height can be made higher.

[0092] (Third Embodiment) Next, with reference to FIGS. 12 to 14, the molten metal driving device 1B according to the third embodiment will be described. FIG. 12 is a partially perspective front view of the molten metal driving device 1B having the magnetic field device 2B. FIG. 13 is a partial cross-sectional view of the side of the molten metal driving device 1B. FIG. 14 is a front view for explaining the generation of the magnetic field by the magnetic field device 2B of the molten metal driving device 1B. In FIGS. 12 to 14, the coils wound around the cores of the magnetic field device 2B are not shown.

[0093] One of the differences between the first embodiment and the third embodiment is that in the third embodiment, the cores 21 to 25 are annular cores. That is, the magnetic field device 2B of the present embodiment corresponds to the one in which both ends of the core of the magnetic field device 2 of the first embodiment (the left end and the right end of the cores 21 to 25 in FIG. 2) are connected to form the cores 21 to 25 into an annular shape. More specifically, the magnetic field device 2B of the third embodiment corresponds to the one in which the cores 21 to 25 of the magnetic field device 2 of the first embodiment are formed into an annular shape so that the yokes 31 to 36 are inside. Hereinafter, the third embodiment will be described centering on the differences.

[0094] The molten metal driving device 1B includes a magnetic field device 2B, a case 5B, a terminal box 6, an AC power supply 7, and a mounting base 8. Since the terminal box 6 and the AC power supply 7 are the same as those described in the first embodiment, detailed descriptions thereof are omitted. The mounting base 8 is a support base for supporting and fixing the cylindrical case 5B in which the magnetic field device 2B is housed.

[0095] The magnetic field device 2B has the same components as the magnetic field device 2 described in the first embodiment. However, as described above, the iron cores 21 to 25 are configured as annular iron cores. As shown in FIG. 13, the annular iron cores 21 to 25 are arranged at intervals so that their respective central axes CL are coaxial.

[0096] As shown in FIG. 12, the yokes 31 to 36 are arranged inside the annular iron cores 21 to 25. In the present embodiment, the yoke 31 faces the yoke 34, the yoke 32 faces the yoke 35, and the yoke 33 faces the yoke 36.

[0097] From the viewpoint of reducing magnetic flux leakage, it is preferable that the annular iron cores 21 to 25 are closed. However, the provision of a gap in a part of the annular iron core is not excluded, and a gap may be provided.

[0098] The annular iron cores 21 to 25 have, for example, a planar shape corresponding to the shape of the mold (casting). When the molten metal driving device 1B is provided in a mold for casting a billet, the iron cores 21 to 25 are annular. When the molten metal driving device 1B is provided in a mold for casting a slab, the iron cores 21 to 25 are rectangular annular.

[0099] In the present embodiment, as shown in FIG. 13, the annular iron cores 21 to 25 are arranged at equal intervals, but they may be arranged at unequal intervals.

[0100] Further, the annular cores 21 to 25 may be thin. As shown in FIG. 13, the annular cores 21 to 25 may be such that the thickness t1 in the direction along the central axis CL (first direction) is smaller than the thickness t2 in the direction orthogonal to the first direction (second direction). Thereby, the cooling efficiency of the magnetic field device 2B can be further improved, and the iron loss can be further reduced. It is preferable to set the thicknesses of the annular core in the first and second directions based on the magnetic saturation value of the annular core so as to ensure a desired magnetomotive force.

[0101] As shown in FIGS. 12 and 13, the case 5B is configured to be able to accommodate the magnetic field device 2B in accordance with the shape of the substantially cylindrical magnetic field device 2B. The magnetic field device 2B is housed in the case 5B such that the inner cylindrical portion of the case 5B is inserted through the annular cores 21 to 25. A spacer (not shown) made of an insulating material is interposed between the annular cores 21 to 25 and the inner cylindrical portion so that the annular cores 21 to 25 maintain a predetermined distance from the inner cylindrical portion of the case 5B. Then, a stud bolt (not shown) is provided so as to penetrate the spacer in the direction of the central axis CL of the magnetic field device 2B. By fixing both ends of this stud bolt to the case 5B, the magnetic field device 2B is fixed in the case 5B.

[0102] In the present embodiment, as shown in FIG. 12, an air inlet 5a and an air outlet 5b are provided in the case 5B. Thereby, similarly to the first embodiment, the cooling air can pass between the cores along the annular cores 21 to 25, and the annular cores 21 to 25 can be efficiently cooled.

[0103] In the present embodiment, the magnetic field device 2B is installed horizontally (that is, the central axis CL of the annular cores 21 to 25 is in the horizontal direction). However, the present invention is not limited to this, and the molten metal driving device 1B may be configured such that the magnetic field device 2B is installed vertically (that is, the central axis CL is in the vertical direction).

[0104] As shown in FIG. 14, the magnetic field device 2B of the present embodiment has a repulsive magnetic field H in accordance with the three-phase alternating current supplied from the AC power supply 7. R , repulsive magnetic field HS and the repulsive magnetic field H T are repeated in this order and radiated toward the central axis CL. More specifically, by supplying the R-phase current, the repulsive magnetic field H R is radiated from the yokes 31, 34 toward the central axis CL. Thereafter, by supplying the S-phase current, the repulsive magnetic field H S is radiated from the yokes 32, 35 toward the central axis CL. Further thereafter, by supplying the T-phase current, the repulsive magnetic field H T is radiated from the yokes 33, 36 toward the central axis CL. Thereafter as well, the repulsive magnetic field is periodically radiated. Thereby, the molten metal inside the annular cores 21 to 25 is driven around the central axis CL.

[0105] The repulsive magnetic fields H R , H S , H T radiated by the yokes 31 to 36 of the magnetic field device 2B have substantially the same intensity distribution along the central axis CL direction. Therefore, according to the molten metal driving device 1B, a uniform stirring force can be generated around the central axis CL.

[0106] Also, the stirring force of the molten metal can be adjusted by adjusting the magnitude and / or frequency of the alternating current output from the AC power supply 7.

[0107] Note that the number of cores in the magnetic field device 2B is not limited to five and may be any number. For example, the number of cores may be determined based on the length of the molten metal to be stirred (for example, the length of the mold 400 described later). Also, the number of yokes is not limited to six and may be a multiple of three such as nine or twelve. By increasing the number of yokes, the molten metal can be stirred more uniformly.

[0108] <Continuous casting system> As an application example of the molten metal driving device 1B according to the third embodiment, a continuous casting system 1300 will be described with reference to FIG. 15.

[0109] The continuous casting system 1300 is configured to receive a supply of molten metal M in a liquid phase state of a conductive material and take out a cast product P in a solid phase state by cooling the molten metal M.

[0110] The continuous casting system 1300 includes a cylindrical mold 400 and a molten metal driving device 1B in which the mold 400 is disposed inside a case 5B. The molten metal driving device 1B is arranged such that the annular iron cores 21 to 25 are coaxial with the mold 400. The mold 400 is provided so as to be inserted into the inner cylindrical portion of the case 5B of the molten metal driving device 1B.

[0111] The mold 400 receives a supply of molten metal M in a liquid phase state from the inlet side and discharges the cast product P in a solid phase state from the outlet side by cooling. The mold 400 of the present embodiment is cylindrical. This cylindrical mold 400 is arranged such that its central axis is coaxial with the central axis CL of the magnetic field device 2B. When the cast product is a slab, a rectangular cylindrical mold is used.

[0112] The mold 400 is made of a refractory material. When it is made of graphite, since graphite is soft in material, a cast product with a smoother surface can be obtained.

[0113] The mold 400 has a water jacket (not shown) for cooling the molten metal M flowing into the mold 400. Cooling water is circulated in the water jacket, and the outer periphery of the mold 400 is cooled by this cooling water. As a result, the molten metal M is rapidly cooled. Note that the water jacket can adopt various known structures.

[0114] As described above, when a three-phase alternating current of the AC power supply 7 is supplied to the magnetic field device 2B, a traveling magnetic field is generated in the mold 400. Eddy currents are generated in the unfrozen molten metal by this traveling magnetic field, and the molten metal M is stirred around the central axis CL. Then, the stirred molten metal is cooled by the water jacket, whereby a uniform and high-quality cast product P can be obtained.

[0115] Thus, according to the continuous casting system 1300, the molten metal M flows into the inlet side (the right side in FIG. 15) of the mold 400, and the cast product P as a product is continuously formed from the outlet side (the left side in FIG. 15).

[0116] As described above, according to the molten metal driving device 1B, since a uniform stirring force can be generated around the central axis CL, the molten metal M in the mold 400 can be uniformly stirred.

[0117] Therefore, according to the above-described continuous casting system 1300, a high-quality cast product P having a uniform composition can be obtained by the strong moving magnetic field generated by the magnetic field device 2B of the molten metal driving device 1B and being uniform around the central axis CL.

[0118] Based on the above description, those skilled in the art may be able to conceive of additional effects and various modifications of the present invention, but the aspects of the present invention are not limited to the individual embodiments described above. Various additions, changes, and partial deletions are possible without departing from the conceptual ideas and spirits of the present invention derived from the content defined in the claims and their equivalents.

[0119] For example, a molten metal transfer system may be configured by providing at least one or more of the molten metal driving devices 1 of the first embodiment on the bottom wall and / or side wall of the trough 200.

[0120] Further, a molten metal stirring system may be configured by housing the molten metal driving device 1A of the second embodiment in the storage space of the furnace 100.

[0121] Further, a molten metal stirring system may be configured by installing the furnace 100 inside the molten metal driving device 1B of the third embodiment.

Explanation of Reference Numerals

[0122] 1 Molten metal driving device 2, 2A, 2B Magnetic field device 21 - 25 Iron core 31 - 36 Yoke Coils 41a, 41b, 44a, 44b Coils 42a, 42b, 45a, 45b Coils 43a, 43b, 46a, 46b Series coils 41 - 46 Cases 5, 5A, 5B Air inlet 5a Air outlet 5b Upper surface 5s Terminal box 6 Wiring inlet 6a AC power supply 7 Mounting base 8 Blower 50 Furnace 100 Gutter 200 Guide plate 210 Container 300 Mold 400 Molten metal stirring system 1100, 1100A Molten metal conveying system 1200 Continuous casting system 1300 Central axis CL Spacing D (between cores) Magnetic fields H1, H2, H3 (generated by coils) H R , H S , H T Repulsive magnetic field Cast product P Thickness T, W (of core)

Claims

1. A molten metal driving device for driving a molten metal, comprising: a plurality of iron cores; a first yoke connecting the plurality of iron cores; a second yoke adjacent to the first yoke and connecting the plurality of iron cores; a third yoke adjacent to the second yoke and connecting the plurality of iron cores; a first coil and a second coil wound around at least one of the plurality of iron cores so as to sandwich the first yoke; a third coil and a fourth coil wound around at least one of the plurality of iron cores so as to sandwich the second yoke; a fifth coil and a sixth coil wound around at least one of the plurality of iron cores so as to sandwich the third yoke, wherein the first coil and the second coil are each wound so as to generate a magnetic field toward the first yoke when a current of a first phase flows, the third coil and the fourth coil are each wound so as to generate a magnetic field toward the second yoke when a current of a second phase flows, and the fifth coil and the sixth coil are each wound so as to generate a magnetic field toward the third yoke when a current of a third phase flows. A molten metal driving device characterized by the above.

2. The molten metal driving device according to claim 1, characterized in that a plurality of sets of the first to third yokes are provided for the plurality of iron cores.

3. The molten metal driving device according to claim 1 or 2, characterized in that the thickness of the plurality of iron cores in the direction in which the first to third yokes extend is smaller than the interval between the plurality of iron cores.

4. The molten metal driving device according to any one of claims 1 to 3, characterized in that the thickness of the plurality of iron cores in the direction in which the first to third yokes extend is smaller than the thickness in the direction orthogonal to the said direction.

5. The first coil and the second coil are connected in series to form a first series coil, the third coil and the fourth coil are connected in series to form a second series coil, the fifth coil and the sixth coil are connected in series to form a third series coil, and the first series coil, the second series coil and the third series coil are star-connected. The molten metal driving device according to any one of claims 1 to 4, characterized by the above.

6. The molten metal driving device according to claim 5, further comprising an AC power supply for flowing an R-phase current through the first series coil, an S-phase current through the second series coil, and a T-phase current through the third series coil.

7. further comprising a case for housing the plurality of iron cores, wherein the case is provided with an air intake for taking in air into the interior of the case and an air outlet for discharging the air in the case to the outside, The molten metal driving device according to any one of claims 1 to 6, wherein the air intake and the air outlet are arranged so as to sandwich the plurality of iron cores.

8. The molten metal driving device according to claim 7, wherein a blower is connected to the air intake.

9. the plurality of iron cores extend parallel to each other, The molten metal driving device according to any one of claims 1 to 8, wherein the first to third yokes are arranged parallel to each other.

10. the plurality of iron cores extend parallel to each other, The molten metal driving device according to any one of claims 1 to 8, wherein the first to third yokes are bent along the extending direction of the plurality of iron cores.

11. the plurality of iron cores are annular iron cores, and are arranged at intervals so that the central axes of each are coaxial, and the first to third yokes are arranged inside the annular iron cores. The molten metal driving device according to any one of claims 1 to 8, characterized in that

12. a furnace for storing molten metal, the molten metal driving device according to claim 9, arranged below the furnace, A molten metal stirring system, characterized by comprising

13. a trough for transporting molten metal, the molten metal driving device according to claim 10, arranged so as to surround at least the lower part of the trough, A molten metal transport system, characterized by comprising

14. a cylindrical mold, the molten metal driving device according to claim 11, wherein the mold is arranged inside the annular iron core, A continuous casting system, characterized by comprising

15. A molten metal driving method for driving molten metal, a step of arranging a molten metal driving device having a magnetic field device adjacent to a furnace for storing molten metal, a trough for transporting molten metal, or a mold The magnetic field device includes a plurality of iron cores, a first yoke connecting the plurality of iron cores, a second yoke adjacent to the first yoke and connecting the plurality of iron cores, a third yoke adjacent to the second yoke and connecting the plurality of iron cores, a first and a second coil wound around at least one of the plurality of iron cores so as to sandwich the first yoke, a third and a fourth coil wound around at least one of the plurality of iron cores so as to sandwich the second yoke, and a fifth and a sixth coil wound around at least one of the plurality of iron cores so as to sandwich the third yoke, and a step of: A step of flowing a current of a first phase through the first coil and the second coil to generate a magnetic field directed toward the first yoke, flowing a current of a second phase through the third coil and the fourth coil to generate a magnetic field directed toward the second yoke, and flowing a current of a third phase through the fifth coil and the sixth coil to generate a magnetic field directed toward the third yoke; A molten metal driving method characterized by comprising the above.

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