Electromagnetic stirring system for casting blank, electromagnetic stirrer and control method of electromagnetic stirrer

Abstract

The invention provides an electromagnetic stirring system for casting blanks, an electromagnetic stirrer and a control method of the electromagnetic stirrer. The electromagnetic stirrer comprises a first iron core with an opening and a coil structure wound on the first iron core; seen from the height direction of the electromagnetic stirrer, a groove defined by the first iron core with the opening is a T-shaped groove; when the coil structure is powered on, an N pole and an S pole which are arranged towards each other are formed on the first iron core.

Description

Technical Field

[0001] The invention relates to the technical field of continuous casting magnetoelectric equipment, in particular to a combined electromagnetic stirrer suitable for profiled blanks. Background Art

[0002] With the rapid development of my country's steel industry, continuous casting machines used in the steel industry have also developed, and electromagnetic stirrer technology has also continued to develop. The function of the electromagnetic stirrer inductor is to stimulate an alternating magnetic field when three-phase or two-phase alternating current is passed through. The alternating magnetic field induces current in the metal liquid. The metal liquid with the induced current is subjected to force in the magnetic field and then stirs, thereby improving the internal structure of the ingot.

[0003] Among the high-efficiency and economical steel types for construction, H-shaped casting billets are widely favored by people due to their advantages such as saving structural weight, strong bearing capacity and good cross-sectional stability, and have become one of the fastest-growing and most widely used economical cross-section steels. Figure 1-1 As shown, the H-shaped billet 20 has two wings 201 and a connecting portion 202 connecting the two wings 201. When viewed from the height direction (top view direction) of the H-shaped billet, the two wings 201 and the connecting portion 202 form an H-shaped structure as a whole.

[0004] As a near-net-shape continuous casting product, profiled billets are undoubtedly the best billets for producing H-type billets. The use of continuous casting profiled billets to roll H-type billets has significant advantages such as low energy consumption, fewer processes, high yield rate and low cost. However, due to the complex cross-sectional shape of H-type billets and the irregular central liquid core, they are more likely to produce various quality defects compared to billets with simple geometric shapes. In addition, the conventional electromagnetic stirrers suitable for square billets or round billets cannot be applied to H-type billets. Therefore, H-type billet continuous casting machines are basically not equipped with electromagnetic stirrers, resulting in loose internal structures, cracks and obvious segregation of H-type billets.

[0005] For example, the patent application with publication number CN113732258A provides a method for reducing the incidence of transverse cracks in micro-alloyed special-shaped billets. This method is aimed at the problem of transverse cracks in the special-shaped billets caused by the thermal stress formed by the secondary cooling in the straightening section of the traditional special-shaped billet continuous casting machine. The method uses an electromagnetic induction heating device to perform temperature compensation on the billet before passing through the straightening section, thereby reducing the thermal stress caused by the temperature gradient. However, this design cannot be used to solve the internal quality problems of H-type billets. Summary of the invention

[0006] The problem to be solved by the present invention is to provide an electromagnetic stirrer to improve at least one of the internal quality problems of loose internal structure, cracks and segregation that are prone to occur in H-type castings with complex cross-sectional shapes.

[0007] In order to solve the above technical problem, the technical solution adopted by the present invention is: an electromagnetic stirrer, comprising a first iron core (1), and a coil structure correspondingly wound on the first iron core (1); When viewed from the height direction of the electromagnetic stirrer, the first iron core (1) forms a ring-shaped structure with an opening (1A), and the groove surrounded by the first iron core (1) is a T-shaped groove (1S); When the coil structure is energized, an N pole and an S pole facing each other are formed on the first iron core (1).

[0008] According to the above technical solution of the present invention, the formed T-shaped groove can accommodate the wing of the H-type casting billet, and the connecting part of the H-type casting billet can pass through the opening. By forming the N pole and the S pole facing each other on the first iron core, the unsolidified molten metal of the wing of the H-type casting billet is stirred, so that the temperature of the unsolidified molten metal inside the wing is relatively uniform, and the flow of the unsolidified part of the liquid in the casting billet is promoted by stirring. When the part of the wing close to the outside solidifies, the liquid is added to the unsolidified part inside, so that there is enough liquid to participate in the solidification process, and the problems of loose organization and cracks inside the casting billet caused by uneven solidification area in the prior art are minimized.

[0009] Furthermore, the first iron core (1) comprises a first connecting section (11), a second connecting section (12), a third connecting section (13), a fourth connecting section (14), and a fifth connecting section (15) which are connected in sequence; An opening (1A) of the first iron core (1) is formed between the first connecting section (11) and the fifth connecting section (15); The third connecting section (13) extends from the second connecting section (12) to the fourth connecting section (14), and the gap between the first connecting section (11) and the fifth connecting section (15) is smaller than the gap between the second connecting section (12) and the fourth connecting section (14), so that the first iron core (1) forms a T-shaped groove (1S).

[0010] The structure for accommodating the wing part of the casting billet is thus formed by the above-mentioned connecting sections connected in sequence.

[0011] Preferably, the connection between the second connecting section (12) and the third connecting section (13), and the connection between the third connecting section (13) and the fourth connecting section (14) are both detachable connections.

[0012] According to the above preferred technical solution of the present invention, for ingots with wings of different widths (i.e., the dimensions along the direction perpendicular to the connecting portion of the ingot), the third connecting sections of different sizes can be replaced by the above detachable connection method to adapt to the electromagnetic stirring of ingots with corresponding wing widths.

[0013] Preferably, the extension direction of the second connecting segment (12) and the extension direction of the fourth connecting segment (14) are both the first direction (L1), the extension direction of the third connecting segment (13) is the second direction (L2), and the first direction (L1) and the second direction (L2) are perpendicular to each other.

[0014] Through the above-mentioned connecting sections connected in sequence, a structure for accommodating the wing portion of the casting billet is formed and adapted to the shape of the wing portion of the casting billet.

[0015] Preferably, the third connecting section (13) is a U-shaped structure; the extension direction of the bottom edge of the U-shaped structure is the first direction (L1); the two end surfaces of the U-shaped structure are respectively connected to the second connecting section (12) and the fourth connecting section (14); and the inner surface of the U-shaped structure is flush with the corresponding surface of the second connecting section (12) and the corresponding surface of the fourth connecting section (14).

[0016] According to the above preferred technical solution of the present invention, the two end faces of the U-shaped structure are respectively connected to the second connecting segment and the fourth connecting segment, so that the third connecting segment will not occupy the space of the T-shaped groove as much as possible, and the third connecting segment connects the second connecting segment and the fourth connecting segment, so that the connection between each connecting segment can be realized in sequence.

[0017] Preferably, the materials of the first connecting section (11), the second connecting section (12), the fourth connecting section (14) and the fifth connecting section (15) are all the first material, the material of the third connecting section (13) is a combination of the first material and the second material, the first material is silicon steel or electrical steel, and the second material is carbon structural steel or stainless steel.

[0018] According to the above preferred technical solution of the present invention, a combination of silicon steel / electrical steel and stainless steel / carbon structural steel is used. The stainless steel / carbon structural steel can reduce the hysteresis loss of the electromagnetic stirrer and reduce the heat generation of the electromagnetic stirrer.

[0019] Furthermore, the coil structure comprises a first coil (21), a second coil (22), a third coil (23), a fourth coil (24), a fifth coil (25), and a sixth coil (26); the power supply end of the first coil (21) and the power supply end of the fourth coil (24) are both first power supply ends (401), the power supply end of the second coil (22) and the power supply end of the fifth coil (25) are both second power supply ends (402), and the power supply end of the third coil (23) and the power supply end of the sixth coil (26) are both third power supply ends (403); the first power supply end (401), the second power supply end (402), and the third power supply end (403) respectively correspond to the A-phase output end, the B-phase output end, and the C-phase output end of the three-phase AC power supply (40).

[0020] Wherein, the arrangement of the coil structure may be: One form: the first coil (21) is wound on the first connecting section (11), the second coil (22) and the third coil (23) are wound on the second connecting section (12), the fourth coil (24) and the fifth coil (25) are wound on the fourth connecting section (14), and the sixth coil (26) is wound on the fifth connecting section (15); or Another form: the first coil (21) is wound on the first connecting section (11), the second coil (22) is wound on the first connecting point, the third coil (23) is wound on the second connecting section (12), the fourth coil (24) is wound on the fourth connecting section (14), the fifth coil (25) is wound on the second connecting point, and the sixth coil (26) is wound on the fifth connecting section (15); the first connecting point is the connecting point between the first connecting section (11) and the second connecting section (12), and the second connecting point is the connecting point between the fourth connecting section (14) and the fifth connecting section (15).

[0021] According to the above technical solution of the present invention, the arrangement of each coil in the coil structure in the connecting section can be realized, and the required magnetic field structure form can be achieved.

[0022] In a preferred technical solution, the first coil (21) and the fourth coil (24) are connected in series or in parallel to the first sub-circuit structure; the second coil (22) and the fifth coil (25) are connected in series or in parallel to the second sub-circuit structure; the third coil (23) and the sixth coil (26) are connected in series or in parallel to the third sub-circuit structure; one end of the first sub-circuit structure, one end of the second sub-circuit structure, and one end of the third sub-circuit structure are respectively connected to the first power supply end (401), the second power supply end (402), and the third power supply end (403); the other end of the first sub-circuit structure, the other end of the second sub-circuit structure, and the other end of the third sub-circuit structure are connected to each other.

[0023] In one connection method, the other end of the first sub-circuit structure, the other end of the second sub-circuit structure, and the other end of the third sub-circuit structure are connected to each other; in another connection method, the other end of the first sub-circuit structure, the other end of the second sub-circuit structure, and the other end of the third sub-circuit structure are connected to each other and then grounded.

[0024] According to the above technical solution of the present invention, power supply to each coil in the coil structure can be achieved.

[0025] Furthermore, a through slot (28) is provided on the inner wall of the first iron core (1) for allowing a corresponding coil of the coil structure to pass through.

[0026] According to the above technical solution of the present invention, the coil structure can pass through the through slot, so that sufficient accommodation space can be formed inside the first iron core for accommodating the wing portion of the ingot.

[0027] Furthermore, the electromagnetic stirrer also comprises a base (4) for mounting the first iron core (1), the base (4) being provided with an H-shaped through hole (41), the shape of the H-shaped through hole (41) being adapted to the shape of the casting blank (20).

[0028] According to the above technical solution of the present invention, the first iron core is installed on the base, and the H-shaped through hole allows the casting to pass through without interfering with the production of the casting.

[0029] Furthermore, the casting blank used for cooperating with the electromagnetic stirrer is an H-shaped casting blank formed by two wings (201) and a connecting portion (202) connected between the two wings (201); the electromagnetic stirrer comprises two first iron cores (1) respectively arranged corresponding to the two wings (202); and the base (4) is provided with a spacing adjustment structure for adjusting the spacing between the two first iron cores (1).

[0030] According to the above technical solution of the present invention, for ingots with different connecting portion lengths, the spacing between the two first iron cores can be adjusted by using a spacing adjustment structure, so that for ingots with different connecting portion lengths, the two first iron cores can be used to surround the two wings of the ingot, thereby facilitating electromagnetic stirring of the wings.

[0031] Furthermore, the casting blank used for cooperating with the electromagnetic stirrer is an H-type casting blank formed by two wings (201) and a connecting portion (202) connected between the two wings (201), or a T-type casting blank formed by connecting the wings (201) and the connecting portion (202); the first iron core (1) is arranged corresponding to the wings (201) of the casting blank (20).

[0032] When the electromagnetic stirrer cooperates with the casting billet (20), the first iron core (1) is wound around the outside of the corresponding wing portion (201) of the casting billet (20).

[0033] According to the above technical solution of the present invention, the two first iron cores can be respectively wound around the outer sides of the two wing parts of the ingot, so as to cooperate with each other and facilitate electromagnetic stirring of the two wing parts.

[0034] According to the same inventive concept, the present invention also provides a control method for the above electromagnetic stirrer, the control method comprising: energizing the coil structure, thereby forming an N pole and an S pole facing each other on the first iron core (1).

[0035] Furthermore, the first iron core (1) comprises a first connecting section (11), a second connecting section (12), a third connecting section (13), a fourth connecting section (14), and a fifth connecting section (15) which are connected in sequence; an opening (1A) of the first iron core (1) is formed between the first connecting section (11) and the fifth connecting section (15); the third connecting section (13) extends from the second connecting section (12) to the fourth connecting section (14), and a gap between the first connecting section (11) and the fifth connecting section (15) is smaller than a gap between the second connecting section (12) and the fourth connecting section (14), so that the first iron core (1) forms a T-shaped groove (1S); The extension direction of the second connecting section (12) and the extension direction of the fourth connecting section (14) are both the first direction (L1), the extension direction of the third connecting section (13) is the second direction (L2), and the first direction (L1) and the second direction (L2) are perpendicular to each other; The electromagnetic stirrer further comprises a second iron core (3) arranged corresponding to each of the first connecting section (11) and the fifth connecting section (15), and a seventh coil (33) is wound around the second iron core (3); The casting blank used for cooperating with the electromagnetic stirrer is an H-shaped casting blank formed by two wings (201) and a connecting portion (202) connected between the two wings (201), or a T-shaped casting blank formed by connecting the wings (201) and the connecting portion (202); When the electromagnetic stirrer is matched with the casting billet (20), the extension direction of the connecting portion (202) and the axial direction of the seventh coil (33) are both in the first direction; a magnetic shielding member (53) is provided between the second iron core (3) and the connecting portion (202); The control method comprises: when the coil structure and the seventh coil (33) are energized: If the magnetic pole formed by the first connecting section (11) is an N pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the first connecting section (11) facing the first connecting section (11) to be an N pole; If the magnetic pole formed by the first connecting section (11) is an S pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the first connecting section (11) facing the first connecting section (11) to be an S pole; If the magnetic pole formed by the fifth connecting segment (15) is an N pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the fifth connecting segment (15) facing the fifth connecting segment (15) to be an N pole; If the magnetic pole formed by the fifth connecting segment (15) is an S pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the fifth connecting segment (15) facing the fifth connecting segment (15) to be an S pole.

[0036] According to the above technical solution of the present invention, since the magnetic poles formed by the first connecting segment / fifth connecting segment and the part of the second iron core corresponding to the first connecting segment / fifth connecting segment facing the first connecting segment / fifth connecting segment are consistent, the first connecting segment / fifth connecting segment and the part of the second iron core facing the first connecting segment / fifth connecting segment form a repulsive magnetic field force, thereby minimizing the divergence of the first connecting segment / fifth connecting segment to the position away from the wing portion in the connecting part of the ingot, that is, minimizing the magnetic force on the position away from the wing portion, and making the magnetic force act on the wing portion or close to the wing portion as much as possible, mainly realizing electromagnetic stirring of the wing portion.

[0037] In a more preferred technical solution, in the second direction (L2), the distance between the first connecting section (11) and the connecting portion (202) is not less than the distance between the second iron core (3) corresponding to the first connecting section (11) and the connecting portion (202), and the distance between the fifth connecting section (15) and the connecting portion (202) is not less than the distance between the second iron core (3) corresponding to the fifth connecting section (15) and the connecting portion (202).

[0038] According to the above technical solution of the present invention, by setting the distance, the second iron core arranged corresponding to the connecting segment (the first connecting segment or the fifth connecting segment) generates a better magnetic field repulsion for the connecting segment.

[0039] According to the same inventive concept, the present invention also provides an electromagnetic stirring system for a cast billet, comprising a crystallizer, wherein the crystallizer has a crystallizer jacket (301) for being arranged outside the cast billet (20), and is characterized in that it also includes the electromagnetic stirrer as described above. The positional relationship between the first iron core and the crystallizer jacket can be in two forms: One form is: in the extension direction of the channel of the casting (20), the distance between the position of the first iron core (1) of the electromagnetic stirrer and the position of the crystallizer jacket (301) is in the range of (0, d1], where d1 is a preset distance.

[0040] Another form is: the first iron core (1) of the electromagnetic stirrer is sleeved on the outside of the crystallizer jacket (301).

[0041] According to the above technical solution of the present invention, since the liquid core ratio at the crystallizer is relatively high, in the above two forms, in the extension direction of the ingot channel, the distance between the position of the first iron core and the position of the crystallizer jacket is 0 or not greater than d1, so as to achieve the stirring of the unsolidified molten steel on the ingot wing as much as possible.

[0042] Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages: 1. The electromagnetic stirrer suitable for H-beam (i.e., special-shaped billet) proposed in the present invention can improve the metallurgical quality of the H-beam, filling the gap in electromagnetic stirring metallurgical equipment for H-beam.

[0043] 2. The electromagnetic stirrer of the present invention comprises a first iron core, and the second connecting section and the third connecting section, and the third connecting section and the fourth connecting section of the first iron core are all detachably connected, and the cross-sectional shapes of H-shaped steels of different sizes can be adapted by replacing the third connecting sections of different sizes; 3. The first iron core of the electromagnetic stirrer of the present invention is arranged around the wing of the H-beam, adapted to the cross-sectional shape of the wing of the H-beam, and significantly improves the electromagnetic stirring efficiency of the electromagnetic stirrer.

[0044] 4. The electromagnetic stirrer suitable for H-shaped blanks proposed by the present invention has a reasonable structural design and a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0046] Figure 1-1 It is a schematic diagram of the three-dimensional structure of an H-shaped casting billet in the prior art; Figure 1-2 It is a top view of a T-shaped casting billet of the prior art; Figure 2 It is a schematic diagram of the three-dimensional structure of an inductor in the electromagnetic stirrer of Example 1 of the present invention; Figure 3 1 is a schematic diagram of the three-dimensional structure of two inductors in the electromagnetic stirrer of Example 1 of the present invention, wherein the coil structure and the through grooves opened on the inner wall of the iron core are not shown; Figure 4 is a top view of two sensors in the electromagnetic stirrer of Example 1 of the present invention; Figure 5A schematic diagram of the liquid stirring direction formed by an inductor and the wing of an H-shaped casting in the electromagnetic stirrer of Example 1 of the present invention, wherein the coil structure and the through grooves opened on the inner wall of the iron core are not shown; Figure 6 is a top view of the base of Example 1 of the present invention; Figure 7 Schematic diagram of the positional relationship between the H-type casting and the electromagnetic stirrer and the crystallizer jacket of the electromagnetic stirring system in Example 1 of the present invention; Figure 8-1 A schematic diagram of a circuit connection structure between each coil and a three-phase AC power supply in Example 1 of the present invention; Figure 8-2 It is a schematic diagram of another circuit connection structure between each coil and a three-phase AC power supply in Embodiment 1 of the present invention; Figure 9-1 to Figure 9-8 They are schematic diagrams of the N pole and S pole formed by an inductor in the electromagnetic stirrer of Example 1 of the present invention in eight different states; Figure 10-1 to Figure 10-3 They are schematic diagrams of magnetic fields formed by an inductor in the electromagnetic stirrer of Example 1 of the present invention in three different states; Fig.11 is a schematic diagram of arrangement of each coil on the first core in the coil structure of Embodiment 2 of the present invention; Fig.12 It is a top view of an electromagnetic stirrer in a powered-on state provided in conjunction with an H-shaped casting billet according to Embodiment 3 of the present invention; Fig.13 yes Fig.12 MM cross-sectional diagram; Fig.14 yes Fig.12 A side view of the second core and the seventh coil; Fig.15 It is a top view of another power-on state of the electromagnetic stirrer provided in conjunction with the H-type casting billet according to Example 3 of the present invention.

[0047] In the above drawings: first core 1; first connecting section 11; second connecting section 12; third connecting section 13; fourth connecting section 14; fifth connecting section 15; opening 1A; T-shaped groove 1S; A first coil 21; a second coil 22; a third coil 23; a fourth coil 24; a fifth coil 25; a sixth coil 26; a junction box 27; a through slot 28; The second iron core 3; the first plate 31; the first extension section 32; the seventh coil 33; Base 4; H-shaped through hole 41; Magnetic shielding member 53; First direction L1; Second direction L2; Ingot 20; wing portion 201; connecting portion 202; receiving groove 20S; Crystallizer jacket 301; A three-phase AC power source 40 ; a first power supply terminal 401 ; a second power supply terminal 402 ; and a third power supply terminal 403 . DETAILED DESCRIPTION The following will be combined with the drawings of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0049] Example 1 This embodiment 1 provides an electromagnetic stirrer, comprising a first iron core 1 and a coil structure correspondingly wound on the first iron core 1; Viewed from the height direction of the electromagnetic stirrer, the first iron core 1 forms a ring-shaped structure with an opening 1A, and the groove surrounded by the first iron core 1 is a T-shaped groove 1S; When the coil structure is energized, an N pole and an S pole facing each other are formed on the first iron core 1. The number of the formed N pole and the number of the formed S pole can be one.

[0050] like Figure 2-Figure 5 As shown, the first core 1 comprises a first connecting section 11, a second connecting section 12, a third connecting section 13, a fourth connecting section 14, and a fifth connecting section 15 which are connected in sequence; An opening 1A of the first core 1 is formed between the first connecting section 11 and the fifth connecting section 15; The third connecting section 13 extends from the second connecting section 12 to the fourth connecting section 14, and the gap between the first connecting section 11 and the fifth connecting section 15 is smaller than the gap between the second connecting section 12 and the fourth connecting section 14, so that the first iron core 1 forms a T-shaped groove 1S. With the phase change of the electrical signal (e.g., current signal) of the first power supply terminal 401, the second power supply terminal 402, and the third power supply terminal 403 (e.g., the phase change of the electrical signal of the A-phase output terminal, the B-phase output terminal, and the C-phase output terminal of the three-phase AC power supply 40), after the first coil 21, the second coil 22, ..., and the sixth coil 26 are energized, within the range surrounded by the first connecting section 11, the second connecting section 12, the third connecting section 13, the fourth connecting section 14, and the fifth connecting section 15, the position where the N pole is formed rotates in a clockwise (or counterclockwise) direction, and the position where the S pole is formed rotates in the same direction as the rotation direction of the N pole, and the position where the N pole and the position where the S pole are always kept relative to each other.

[0051] The connection between the second connection segment 12 and the third connection segment 13, and the connection between the third connection segment 13 and the fourth connection segment 14 can be set to be detachable, and the specific structural form can be: the two end faces of the third connection segment 13 are provided with through holes extending in the first direction, and the positions of the second connection segment 12 corresponding to the through holes of the third connection segment 13 and the positions of the fourth connection segment 14 corresponding to the through holes of the third connection segment 13 can be provided with installation grooves, for example, the bolts can be passed through the through holes of the third connection segment 13 and then extended into the corresponding installation grooves on the second connection segment 12 / fourth connection segment 14, so as to achieve detachable connection. Alternatively, the first connection segment 11, the second connection segment 12, the third connection segment 13, the fourth connection segment 14, and the fifth connection segment 15 form an integrated structure.

[0052] Preferably, the extending direction of the second connecting segment 12 and the extending direction of the fourth connecting segment 14 are both the first direction L1, the extending direction of the third connecting segment 13 is the second direction L2, and the first direction L1 and the second direction L2 are perpendicular to each other.

[0053] Preferably, the third connecting section 13 is a U-shaped structure; the extension direction of the bottom edge of the U-shaped structure is the second direction L2. The two end surfaces of the U-shaped structure are respectively connected to the second connecting section 12 and the fourth connecting section 14; the inner surface of the U-shaped structure is flush with the corresponding surface of the second connecting section 12 and the corresponding surface of the fourth connecting section 14.

[0054] Preferably, the materials of the first connecting segment 11, the second connecting segment 12, the fourth connecting segment 14 and the fifth connecting segment 15 are all the first material, the material of the third connecting segment 13 is a combination of the first material and the second material, the first material is silicon steel or electrical steel, and the second material is carbon structural steel or stainless steel.

[0055] like Figure 2 , Figure 4 , Figure 7 As shown, the coil structure includes a first coil 21 , a second coil 22 , a third coil 23 , a fourth coil 24 , a fifth coil 25 , and a sixth coil 26 .

[0056] The power supply end of the first coil 21 and the power supply end of the fourth coil 24 are both the first power supply end 401, the power supply end of the second coil 22 and the power supply end of the fifth coil 25 are both the second power supply end 402, and the power supply end of the third coil 23 and the power supply end of the sixth coil 26 are both the third power supply end 403.

[0057] The first power supply terminal 401 , the second power supply terminal 402 , and the third power supply terminal 403 correspond to the A-phase output terminal, the B-phase output terminal, and the C-phase output terminal of the three-phase AC power source 40 , respectively.

[0058] The first coil 21 is wound on the first connecting section 11, the second coil 22 is wound on the second connecting section 12, the third coil 23 is wound on the second connecting section 12, the fourth coil 24 is wound on the fourth connecting section 14, the fifth coil 25 is wound on the fourth connecting section 14, and the sixth coil 26 is wound on the fifth connecting section 15.

[0059] The first connection point is a connection point between the first connection segment 11 and the second connection segment 12 , and the second connection point is a connection point between the fourth connection segment 14 and the fifth connection segment 15 .

[0060] like Figure 8-1 As shown, in one connection mode, the first coil 21 and the fourth coil 24 are connected in series to the first sub-circuit structure; the second coil 22 and the fifth coil 25 are connected in series to the second sub-circuit structure; the third coil 23 and the sixth coil 26 are connected in series to the third sub-circuit structure; one end of the first sub-circuit structure, one end of the second sub-circuit structure, and one end of the third sub-circuit structure are respectively connected to the first power supply terminal 401, the second power supply terminal 402, and the third power supply terminal 403; the other end of the first sub-circuit structure, the other end of the second sub-circuit structure, and the other end of the third sub-circuit structure are connected to each other at point P (i.e., forming a star connection), and point P does not need to be grounded.

[0061] like Figure 8-2 Another connection method shown is Figure 8-1 The difference is that the other end of the first sub-circuit structure, the other end of the second sub-circuit structure, and the other end of the third sub-circuit structure are connected to each other and then grounded.

[0062] In other embodiments, the connection between the first coil 21 and the fourth coil 24, the connection between the second coil 22 and the fifth coil 25, and the connection between the third coil 23 and the sixth coil 26 may also be in parallel. The series and parallel forms of the coils in different sub-circuits are independent of each other. That is, the coils in one sub-circuit may be connected in series (or in parallel), and the coils in other sub-circuits may be connected in parallel (or in series).

[0063] In this embodiment, the power supply signals of the first coil 21 and the fourth coil 24 have the same phase, the power supply signals of the second coil 22 and the fifth coil 25 have the same phase, and the power supply signals of the third coil 23 and the sixth coil 26 have the same phase. The power supply signal phases of the first coil 21, the second coil 22, and the third coil 23 differ by 120°. That is, the initial phases of the power supply signals of the first coil 21, the second coil 22, and the third coil 23 are θ1, θ2, and θ3, respectively, where θ2-θ1=θ3-θ2=120°.

[0064] Figure 9-1 to Figure 9-8They are schematic diagrams of the N pole and S pole formed by an inductor in the electromagnetic stirrer of Example 1 of the present invention in eight different states; Figure 10-1 to Figure 10-3 Schematic diagrams of magnetic fields formed by an inductor in the electromagnetic stirrer of Example 1 of the present invention in three different states, namely Figure 10-1 to Figure 10-3 The phase angles of the power supply signals corresponding to the first coil 21 are 0 degrees, 60 degrees, and 120 degrees respectively.

[0065] like Figure 2 As shown, the inner wall of the first core 1 is provided with a through slot 28 for the corresponding coil of the coil structure to pass through. Each coil from the first coil 21 to the sixth coil 26 is correspondingly provided with a through slot 28, and the part of each coil located on the inner side of the first core 1 passes through the through slot 28 along the height direction of the first core 1.

[0066] like Figure 6 As shown, the electromagnetic stirrer further comprises a base 4 for mounting the first iron core 1 , and an H-shaped through hole 41 is formed on the base 4 , and the shape of the H-shaped through hole 41 is adapted to the shape of the ingot 20 .

[0067] Preferably, the ingot used to cooperate with the electromagnetic stirrer is an H-type ingot formed by two wings 201 and a connecting portion 202 connected between the two wings 201, the electromagnetic stirrer includes two first iron cores 1 respectively arranged corresponding to the two wings 202, and the base 4 is provided with a spacing adjustment structure for adjusting the spacing between the two first iron cores 1.

[0068] Specific form of spacing adjustment structure: According to the actual cross-sectional dimensions of the ingot, a plurality of positioning portions (such as positioning grooves or positioning blocks) for cooperating with the outer periphery of the first iron core are provided on the base 4. When the electromagnetic stirrer cooperates with the corresponding ingot, the two first iron cores are limited by the corresponding positioning portions, thereby realizing the adjustment of the spacing between the two first iron cores 1.

[0069] The structural form of the casting billet used to cooperate with the electromagnetic stirrer can be: (1) If Figure 1-1 As shown, the casting billet is an H-shaped casting billet, which is formed by two wing portions 201 and a connecting portion 202 connected between the two wing portions 201; (2) If Figure 1-2 As shown, the ingot is a T-shaped ingot, which is formed by connecting a wing portion 201 and a connecting portion 202 .

[0070] The first iron core 1 is arranged corresponding to the wing portion 201 of the casting blank 20 ; when the electromagnetic stirrer is matched with the casting blank 20 , the first iron core 1 is wound around the outer side of the corresponding wing portion 201 .

[0071] According to the same inventive concept, the present invention also provides a control method for an electromagnetic stirrer, the control method comprising: energizing the coil structure, thereby forming an N pole and an S pole facing each other on the first iron core 1 .

[0072] According to the same inventive concept, the present invention also provides an electromagnetic stirring system for a cast billet, comprising a crystallizer having a crystallizer jacket 301 for being arranged outside the cast billet 20, and also comprising the above-mentioned electromagnetic stirrer, such as Figure 7 shown.

[0073] In the extension direction of the channel of the ingot 20 (in the height direction in this embodiment), the distance between the position of the first core 1 of the electromagnetic stirrer and the position of the crystallizer housing 301 is in the range of [0, d1], where d1 is a preset distance; or The mold jacket 301 may be a mold copper sleeve. The value range of d1 may be (0, 20 m], for example, d1 may be 3 m, 5 m, 10 m, 20 m. That is, the electromagnetic stirrer may be set at a position where the liquid core of the ingot is not solidified.

[0074] like Figure 7 As shown, in this embodiment, when the first iron core 1 of the electromagnetic stirrer and the crystallizer housing 301 are located at the same height, the crystallizer housing 301 is sleeved on the outside of the ingot 20 and has the same shape as the ingot 20. The ingot 20 passes through the inner space of the crystallizer housing 301. The first iron core 1 is arranged on the outside of the crystallizer housing 301. That is, the crystallizer housing 301 also has a wing, and the first iron core 1 is wound around the outside of the corresponding wing of the crystallizer housing 301.

[0075] The value range of the angle between the extension direction of the first connecting segment 11 and the extension direction of the second connecting segment 12 and the value range of the angle between the extension direction of the fourth connecting segment 14 and the extension direction of the fifth connecting segment 15 are both [90°, 120°].

[0076] The surfaces of the first core 1 located on both sides of the groove may be flush with the outer surface of the coil accommodated in the groove.

[0077] When the electromagnetic stirrer cooperates with the ingot 20 and the ingot is an H-type ingot, each first core 1 is wound around the outside of the corresponding wing 201 of the ingot 20, and the connecting portion 202 of the ingot 20 extends from at least one opening 1A of the first core 1 to the opening 1A of another first core 1.

[0078] The receiving groove 20S is surrounded by two wing portions 201 and a connecting portion 202 of the H-shaped casting blank 20, and the two receiving grooves 20S are respectively located on both sides of the connecting portion 202. The first connecting section and the fifth connecting section extend into the two receiving grooves 20S formed by the H-shaped casting blank 20.

[0079] When the electromagnetic stirrer cooperates with the ingot 20 and the ingot is a T-shaped ingot, the first core 1 is wound around the outside of the corresponding wing 201 of the ingot 20 , and the connecting portion 202 of the ingot 20 at least extends outward from the opening 1A of the first core 1 .

[0080] The second iron core 3 includes two first plates 31 which are parallel to each other and arranged toward each other in a first direction, and a first extension section 32 connected between the two first plates 31. The seventh coil 33 is wound on the first extension section 32 so as to be accommodated in a groove formed by the two first plates 31 and the first extension section 32. The extension direction of the first extension section 32 is the first direction. The first direction is perpendicular to the surface of the first plate 31.

[0081] The following is a further detailed description of Example 1 of the present invention.

[0082] The present invention overcomes the shortcomings of existing conventional electromagnetic stirrers and provides a combined electromagnetic stirrer specifically for profiled blanks, which can not only improve the electromagnetic stirring efficiency of the electromagnetic stirrer, but also ensure the stirring efficiency while combining different third connecting sections to be suitable for profiled blanks of different cross-sectional sizes, that is, the magnetic field stirring efficiency is improved and the versatility of the electromagnetic stirrer is improved. The present invention can make the electromagnetic field penetrate the liquid core more efficiently and improve the work efficiency of the electromagnetic field in driving the liquid core to move. In this embodiment, the profiled blank refers to an H-shaped blank, a T-shaped blank, and an I-beam.

[0083] An electromagnetic stirrer suitable for profiled blanks includes two electromagnetic inductors. Each inductor includes a first iron core and a coil structure wound on the first iron core. The two electromagnetic inductors can be made into rotationally symmetrical or different structures according to actual needs.

[0084] Each electromagnetic inductor is equipped with a junction box 27 and a water inlet and outlet (the cooling channel can be arranged in the inner cavity of the coil along the axial direction of each coil), which is convenient for connecting the power cord on site and the cooling water circuit. The third connecting section 13 can be of multiple models (with different lengths in the second direction), but its interface with the second connecting section 12 / the fourth connecting section 14 can be set to be consistent, and different third connecting sections can be selected to adapt to different sections of the billet on site. The electromagnetic stirrer is arranged around the periphery of the continuous casting billet, adapted to the cross-sectional shape of the special-shaped billet, and can be arranged between two pairs of support rollers. The electromagnetic stirrer can be fixed using a platform (such as a base 4) or an existing structure of the continuous casting machine. The support roller is the content of the existing technology. The connection method of the third connecting section 2 and the second connecting section 12 / the fourth connecting section 14 is detachably connected by fasteners or quick connectors. The connection method can be fastened by screws, bolts or studs. The winding of each coil can be wound by short-distance winding or Cramer winding. The winding of the coil is the content of the existing technology. In order to facilitate the arrangement of the winding of the winding, the coil can use a flat wire winding. In order to achieve more stable and excellent heat dissipation performance, the coil can use copper tube winding.

[0085] The third connection section is made of silicon steel sheet or other magnetic conductive materials, and its function is to conduct the magnetic circuit between the second connection section and the third connection section. The third connection section 2 can be made of a combination of silicon steel and carbon structural steel, or electrical steel and stainless steel. Stainless steel can reduce the hysteresis loss of the electromagnetic stirrer and stabilize the heating of the electromagnetic stirrer, that is, to ensure the heat dissipation performance.

[0086] The electromagnetic stirrer can be installed on the periphery of the copper sleeve of the crystallizer of the beam blank continuous casting machine. The liquid core ratio at the crystallizer is high, and the electromagnetic stirrer can stir the molten steel as much as possible. The electromagnetic stirrer can be electrically controlled separately, and the direction of the rotating magnetic field can be changed only by adjusting the electrical parameters. For example, the electromagnetic stirrer is installed in the secondary cooling section area of ​​the beam blank continuous casting machine. The specific installation position is in the middle space between the two pairs of support rollers of the beam blank continuous casting machine. The electromagnetic stirrer is fixed on a special base on the continuous casting machine. The material of the iron core can be selected from electrical steel or silicon steel, and the coil material can be selected from pure copper.

[0087] like Figure 4 , Figure 5 , Figure 9-1 to Figure 9-8 , Figure 10-1 to Figure 10-3 Each electromagnetic stirrer generates a frequency-adjustable rotating magnetic field in the same or opposite direction. The rotating magnetic field passes through the main liquid core of the profiled blank, inducing current in the metal liquid. The induced current drives the metal liquid to move under the force of the magnetic field, thereby improving the casting quality of the profiled blank.

[0088] Example 2 like Fig.11As shown, the difference between this embodiment 2 and embodiment 1 is that: the second coil 22 is wound outside the first connection, the fifth coil 25 is wound outside the second connection, the first connection is the connection between the first connection section 11 and the second connection section 12, and the second connection is the connection between the fourth connection section 14 and the fifth connection section 15; The power supply and magnetic pole formation of the coil structure of the second embodiment are similar to those of the first embodiment and will not be described in detail here.

[0089] Example 3 like Figure 12-Figure 15 This is a schematic diagram of the structure of Example 3 of the present invention.

[0090] The difference between the present embodiment 3 and the embodiment 1 is that: the electromagnetic stirrer further comprises a second iron core 3 corresponding to each of the first connecting section 11 and the fifth connecting section 15, and a seventh coil 33 is wound around the second iron core 3; The casting blank used for cooperating with the electromagnetic stirrer is an H-shaped casting blank formed by two wings 201 and a connecting portion 202 connected between the two wings 201, or a T-shaped casting blank formed by connecting the wings 201 and the connecting portion 202; When the electromagnetic stirrer is matched with the casting slab 20, the extending direction of the connecting portion 202 and the axial direction of the seventh coil 33 are both in the first direction; a magnetic shielding member 53 is provided between the second iron core 3 and the connecting portion 202; The control method comprises: when the coil structure and the seventh coil 33 are energized: If the magnetic pole formed by the first connecting segment 11 is a north pole, the seventh coil 33 is powered so that the magnetic pole formed by the portion of the second core 3 corresponding to the first connecting segment 11 facing the first connecting segment 11 is a north pole; If the magnetic pole formed by the first connecting segment 11 is an S pole, the seventh coil 33 is powered so that the magnetic pole formed by the portion of the second core 3 corresponding to the first connecting segment 11 facing the first connecting segment 11 is an S pole; If the magnetic pole formed by the fifth connecting segment 15 is a north pole, the seventh coil 33 is powered so that the magnetic pole formed by the portion of the second core 3 corresponding to the fifth connecting segment 15 facing the fifth connecting segment 15 is a north pole; If the magnetic pole formed by the fifth connecting segment 15 is an S pole, the seventh coil 33 is powered so that the magnetic pole formed by the portion of the second core 3 corresponding to the fifth connecting segment 15 facing the fifth connecting segment 15 is an S pole; Preferably, in the second direction L2, the distance between the first connecting segment 11 and the connecting portion 202 is not less than the distance between the second iron core 3 corresponding to the first connecting segment 11 and the connecting portion 202, and the distance between the fifth connecting segment 15 and the connecting portion 202 is not less than the distance between the second iron core 3 corresponding to the fifth connecting segment 15 and the connecting portion 202.

[0091] In this embodiment 3, the second core corresponding to the first connecting section 11 of one first core 1 and the second core corresponding to the fifth connecting section 15 of another first core 1 form an integrated structure. Of course, two second cores corresponding to the two first cores can also be arranged on one side of the connecting portion.

[0092] It should be noted that the various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0093] The embodiments of the present invention are described in detail above, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made according to the scope of the present invention should still be included in the scope of the present invention. After reading the present invention, the modifications of various equivalent forms of the present invention by those skilled in the art all fall within the scope defined by the claims attached to this application. In the absence of conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

Claims

1. An electromagnetic stirrer, characterized in that: It comprises a first iron core (1) and a coil structure correspondingly wound on the first iron core (1); When viewed from the height direction of the electromagnetic stirrer, the first iron core (1) forms a ring-shaped structure with an opening (1A), and the groove surrounded by the first iron core (1) is a T-shaped groove (1S); When the coil structure is energized, an N pole and an S pole facing each other are formed on the first iron core (1).

2. The electromagnetic stirrer according to claim 1, characterized in that: The first iron core (1) comprises a first connecting section (11), a second connecting section (12), a third connecting section (13), a fourth connecting section (14), and a fifth connecting section (15) which are connected in sequence; An opening (1A) of the first iron core (1) is formed between the first connecting section (11) and the fifth connecting section (15); The third connecting section (13) extends from the second connecting section (12) to the fourth connecting section (14), and the gap between the first connecting section (11) and the fifth connecting section (15) is smaller than the gap between the second connecting section (12) and the fourth connecting section (14), so that the first iron core (1) forms a T-shaped groove (1S); Preferably, the connection between the second connecting section (12) and the third connecting section (13), and the connection between the third connecting section (13) and the fourth connecting section (14) are both detachable connections; Preferably, the extension direction of the second connecting section (12) and the extension direction of the fourth connecting section (14) are both the first direction (L1), the extension direction of the third connecting section (13) is the second direction (L2), and the first direction (L1) and the second direction (L2) are perpendicular to each other; Preferably, the third connecting section (13) is a U-shaped structure; the extension direction of the bottom edge of the U-shaped structure is the second direction (L2); the two end surfaces of the U-shaped structure are respectively connected to the second connecting section (12) and the fourth connecting section (14); the inner surface of the U-shaped structure is flush with the corresponding surface of the second connecting section (12) and the corresponding surface of the fourth connecting section (14); Preferably, the materials of the first connecting section (11), the second connecting section (12), the fourth connecting section (14) and the fifth connecting section (15) are all the first material, the material of the third connecting section (13) is a combination of the first material and the second material, the first material is silicon steel or electrical steel, and the second material is carbon structural steel or stainless steel.

3. The electromagnetic stirrer according to claim 2, characterized in that: The coil structure comprises a first coil (21), a second coil (22), a third coil (23), a fourth coil (24), a fifth coil (25), and a sixth coil (26); The power supply end of the first coil (21) and the power supply end of the fourth coil (24) are both the first power supply end (401), the power supply end of the second coil (22) and the power supply end of the fifth coil (25) are both the second power supply end (402), and the power supply end of the third coil (23) and the power supply end of the sixth coil (26) are both the third power supply end (403); The first power supply end (401), the second power supply end (402), and the third power supply end (403) respectively correspond to the A-phase output end, the B-phase output end, and the C-phase output end of the three-phase AC power supply (40); The first coil (21) is wound on the first connecting section (11), the second coil (22) is wound on the second connecting section (12) or wound on the first connecting point, the third coil (23) is wound on the second connecting section (12), the fourth coil (24) is wound on the fourth connecting section (14), the fifth coil (25) is wound on the fourth connecting section (14) or wound on the second connecting point, and the sixth coil (26) is wound on the fifth connecting section (15); The first connection point is a connection point between the first connection section (11) and the second connection section (12), and the second connection point is a connection point between the fourth connection section (14) and the fifth connection section (15); Preferably: The first coil (21) and the fourth coil (24) are connected in series or in parallel to the first sub-circuit structure; The second coil (22) and the fifth coil (25) are connected in series or in parallel to the second sub-circuit structure; The third coil (23) and the sixth coil (26) are connected in series or in parallel to the third sub-circuit structure; One end of the first sub-circuit structure, one end of the second sub-circuit structure, and one end of the third sub-circuit structure are respectively connected to the first power supply end (401), the second power supply end (402), and the third power supply end (403); The other end of the first sub-circuit structure, the other end of the second sub-circuit structure, and the other end of the third sub-circuit structure are connected to each other.

4. The electromagnetic stirrer according to any one of claims 1 to 3, characterized in that: The inner wall of the first iron core (1) is provided with a through slot (28) for allowing the corresponding coil of the coil structure to pass through.

5. The electromagnetic stirrer according to any one of claims 1 to 3, characterized in that: The electromagnetic stirrer further comprises a base (4) for mounting the first iron core (1), the base (4) being provided with an H-shaped through hole (41), the shape of the H-shaped through hole (41) being adapted to the shape of the casting blank (20); Preferably, the casting blank used for cooperating with the electromagnetic stirrer is an H-shaped casting blank formed by two wings (201) and a connecting portion (202) connected between the two wings (201), the electromagnetic stirrer comprises two first iron cores (1) respectively arranged corresponding to the two wings (202), and the base (4) is provided with a spacing adjustment structure for adjusting the spacing between the two first iron cores (1).

6. The electromagnetic stirrer according to any one of claims 1 to 3, characterized in that: The casting blank used for cooperating with the electromagnetic stirrer is an H-shaped casting blank formed by two wings (201) and a connecting portion (202) connected between the two wings (201), or a T-shaped casting blank formed by connecting the wings (201) and the connecting portion (202); The first iron core (1) is arranged corresponding to the wing portion (201) of the casting blank (20); When the electromagnetic stirrer cooperates with the casting billet (20), the first iron core (1) is wound around the outside of the corresponding wing portion (201).

7. A control method for an electromagnetic stirrer according to any one of claims 1 to 6, characterized in that: The control method comprises: energizing the coil structure, thereby forming an N pole and an S pole arranged toward each other on the first iron core (1).

8. The control method of the electromagnetic stirrer according to claim 7, characterized in that: The first iron core (1) comprises a first connecting section (11), a second connecting section (12), a third connecting section (13), a fourth connecting section (14), and a fifth connecting section (15) which are connected in sequence; an opening (1A) of the first iron core (1) is formed between the first connecting section (11) and the fifth connecting section (15); the third connecting section (13) extends from the second connecting section (12) to the fourth connecting section (14), and a gap between the first connecting section (11) and the fifth connecting section (15) is smaller than a gap between the second connecting section (12) and the fourth connecting section (14), so that the first iron core (1) forms a T-shaped groove (1S); The extension direction of the second connecting section (12) and the extension direction of the fourth connecting section (14) are both the first direction (L1), the extension direction of the third connecting section (13) is the second direction (L2), and the first direction (L1) and the second direction (L2) are perpendicular to each other; The electromagnetic stirrer further comprises a second iron core (3) arranged corresponding to each of the first connecting section (11) and the fifth connecting section (15), and a seventh coil (33) is wound around the second iron core (3); The casting blank used for cooperating with the electromagnetic stirrer is an H-shaped casting blank formed by two wings (201) and a connecting portion (202) connected between the two wings (201), or a T-shaped casting blank formed by connecting the wings (201) and the connecting portion (202); When the electromagnetic stirrer is matched with the casting billet (20), the extension direction of the connecting portion (202) and the axial direction of the seventh coil (33) are both in the first direction; a magnetic shielding member (53) is provided between the second iron core (3) and the connecting portion (202); The control method comprises: when the coil structure and the seventh coil (33) are energized: If the magnetic pole formed by the first connecting section (11) is an N pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the first connecting section (11) facing the first connecting section (11) to be an N pole; If the magnetic pole formed by the first connecting section (11) is an S pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the first connecting section (11) facing the first connecting section (11) to be an S pole; If the magnetic pole formed by the fifth connecting segment (15) is an N pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the fifth connecting segment (15) facing the fifth connecting segment (15) to be an N pole; If the magnetic pole formed by the fifth connecting segment (15) is an S pole, the power supply to the seventh coil (33) causes the magnetic pole formed by the portion of the second iron core (3) arranged corresponding to the fifth connecting segment (15) facing the fifth connecting segment (15) to be an S pole.

9. The control method of the electromagnetic stirrer according to claim 8, characterized in that: In the second direction (L2), the distance between the first connecting section (11) and the connecting portion (202) is not less than the distance between the second iron core (3) corresponding to the first connecting section (11) and the connecting portion (202), and the distance between the fifth connecting section (15) and the connecting portion (202) is not less than the distance between the second iron core (3) corresponding to the fifth connecting section (15) and the connecting portion (202).

10. An electromagnetic stirring system for a cast billet, comprising a crystallizer, the crystallizer having a crystallizer jacket (301) for being arranged outside the cast billet (20), characterized in that: Also includes an electromagnetic stirrer as described in any one of claims 1-6; In the extension direction of the channel of the casting slab (20), the distance between the position of the first iron core (1) of the electromagnetic stirrer and the position of the crystallizer housing (301) is in the range of (0, d1], where d1 is a preset distance; or The first iron core (1) of the electromagnetic stirrer is sleeved on the outside of the crystallizer outer shell (301).

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