Slab electromagnetic stirring device for wide and thick plates

Abstract

The application provides a high magnetic field slab electromagnetic stirring device for wide and thick plates, which comprises an electromagnetic stirring structure; the electromagnetic stirring structure comprises an iron core (3) and a coil (4); the iron core (3) is integrally punched and formed by silicon steel sheets and then is stacked layer by layer; the coil (4) is wound in the slot of the iron core (3); the iron core (3) is fixed by means of the penetrating mode of the insulating bolt (7) between each wire package of the coil (4); the part of the iron core (3) opposite to the area of the water gap (1) adopts an arc-shaped iron core structure (5), and the coil (4) is wound on the arc-shaped iron core structure (5), so that the magnetic circuit is continuous on the whole cross section. The application can keep the magnetic circuit continuous on the whole cross section of the cast slab, and is especially suitable for the cross section of 2150mm-4300mm of the wide and thick plate.

Description

Technical Field

[0001] This invention relates to the field of electromagnetic stirring of slabs, specifically to electromagnetic stirring apparatus for slabs of thick plates, and especially to electromagnetic stirring apparatus for slabs of thick plates with high magnetic field. Background Technology

[0002] The reason why the electromagnetic stirrer for thick slabs is so heavy is that it is installed inside the crystallizer jacket. If its cross-sectional dimensions exceed 2150mm, the weight of the electromagnetic stirrer exceeds the bearing capacity of the crystallizer jacket, which will cause the jacket to deform.

[0003] To address this, patent document CN113664170A discloses an electromagnetic stirring device for a slab crystallizer, comprising a multi-segment linear magnetic field generator. The linear magnetic field generator includes an iron core, which comprises iron core laminations. An iron core pressure plate is located outside the iron core laminations. Multiple coils are wound around the outside of the iron core, and the coils are made of hollow copper tubing. A shield is located outside the non-working surface of the coils. The multi-segment linear magnetic field generators are connected together via a housing frame. An electrical connection box and a coolant connection pipe pass through the housing frame. Cooling water passage one passes through the iron core pressure plate, and cooling water passage two passes through the shield. In other words, this patent document employs a segmented iron core design for thick slabs, equivalent to using two electromagnetic stirrers on a single cross-section.

[0004] However, the shortcomings of the existing technology are: the magnetic circuit is broken in the middle, the magnetic field on the cross-section of the cast billet is reduced and becomes extremely uneven (e.g., Figure 2 (As shown); the middle is interrupted and there is no stirring, so the quality of the billet center cannot be improved, especially the bubble defect. This is right in the sprue area. The argon gas blown out of the sprue cannot be stirred and removed and will be captured by the solidified billet shell, forming bubble defects and affecting the quality of the billet. For some small cross-section billets, especially in the range of 1650-2150mm, the electromagnetic stirring effect is greatly reduced due to the insufficient number of poles, and it cannot play its role. Summary of the Invention

[0005] In view of the deficiencies in the prior art, the purpose of this invention is to provide an electromagnetic stirring device for slabs of thick plates.

[0006] An electromagnetic stirring device for slabs of thick plates according to the present invention includes an electromagnetic stirring structure;

[0007] The electromagnetic stirring structure includes: an iron core 3 and a coil 4;

[0008] Core 3 is made of silicon steel sheets through integral stamping and then stacked layer by layer;

[0009] Coil 4 is wound inside the slot of iron core 3;

[0010] The iron core 3 is fixed between each coil of coil 4 by means of insulating bolts 7 passing through it.

[0011] The portion of the iron core 3 facing the water inlet 1 adopts an arc-shaped iron core structure 5, and a coil 4 is wound on the arc-shaped iron core structure 5 to maintain the magnetic circuit continuity across the entire cross-section.

[0012] Preferably, it also includes a crystallizer jacket 2;

[0013] The electromagnetic stirring structure is installed in the crystallizer jacket 2.

[0014] Preferably, a square copper tube water cooling method is used to reduce the coil temperature.

[0015] Preferably, the insulating bolt 7 is fitted with an insulating sleeve 8.

[0016] Preferably, a support beam 6 is provided in the middle of the crystallizer jacket 2. The support beam 6 is made of carbon steel so that the magnetic field generated by the electromagnetic stirring is introduced into the water inlet 1 area through the support beam 6.

[0017] Preferably, during operation, the entire electromagnetic stirring structure is installed in the crystallizer jacket 2 cavity via flange 9.

[0018] Preferably, the cross-section of the thick plate exceeds 2150mm.

[0019] Preferably, the cross-section of the thick plate is 2150mm-4300mm.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention can maintain the magnetic circuit continuous and unlayered throughout the entire cross-section of the cast billet, and is especially suitable for wide and thick plates with a cross-section of 2150mm-4300mm. The wider the cast billet, the more poles the electromagnetic stirring design has, and the greater and more uniform the magnetic field strength, thereby making full use of the function of multiple magnetic poles in wide and thick plates, and achieving high strength and uniformity of the electromagnetic stirring magnetic field in wide and thick plates.

[0022] 2. This invention achieves an integrated design of a thick plate electromagnetic stirring core by adopting an arc-shaped iron core structure with a coil wound in the center.

[0023] 3. This invention uses a crystallizer jacket 2 reinforced with a diameter plate made of carbon steel, which contacts the bow-shaped iron core to enhance the magnetic field at the bow-shaped part of the crystallizer, thereby increasing the stirring intensity in the nozzle area and improving the quality of the central part of the cast billet. Attached Figure Description

[0024] Other features, objects, and advantages of the present invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the present invention.

[0026] Figure 2 This is a schematic diagram showing a segmented magnetic field that becomes smaller, non-uniform, and without a central magnetic field.

[0027] Figure 3 A schematic diagram illustrating the design of a monolithic iron core with a large and uniform magnetic field strength.

[0028] The diagram shows:

[0029] Water inlet 1

[0030] Crystallizer Jacket 2

[0031] Iron Core 3

[0032] Coil 4

[0033] Bow-shaped iron core structure 5

[0034] Support beam 6

[0035] Insulating bolt 7

[0036] Insulating sleeve 8

[0037] Flange 9 Detailed Implementation

[0038] The present invention will now be described in detail with reference to specific embodiments. These embodiments will help those skilled in the art to further understand the present invention, but do not limit the invention in any way. It should be noted that those skilled in the art can make several changes and improvements without departing from the concept of the present invention. These all fall within the protection scope of the present invention.

[0039] The essence of a slab electromagnetic stirrer is to control the flow, heat transfer, and even solidification of molten steel during continuous casting by using electromagnetic force. This results in a significant improvement in the surface and subsurface quality of the continuously cast slab, increasing the cleanliness of the steel, expanding the equiaxed crystal zone of the slab, reducing compositional segregation, and mitigating or eliminating central porosity and central shrinkage cavities, thereby achieving the goal of producing high-quality, high-grade steel.

[0040] Traditional electromagnetic stirrers for slabs with cross-sections below 2150mm are designed with an integral iron core. The integral iron core design ensures that the magnetic circuit is not layered, and as the cross-section increases, the number of magnetic poles increases. The more magnetic poles there are, the stronger and more uniform the magnetic field becomes, resulting in a better stirring effect.

[0041] However, for cross-sections exceeding 2150mm, the traditional slab stirring device structure is difficult to apply to wide and thick plates because the crystallizer jacket cannot withstand the weight of the electromagnetic stirring.

[0042] According to the present invention, an electromagnetic stirring device for thick plates is provided. The iron core 3 is integrally stamped into an arc shape from silicon steel sheets, and then stacked layer by layer. This increases the strength of the iron core, reduces eddy currents in the silicon steel sheets, and reduces heat generation in the iron core 3. The coil 4 is wound inside the slots of the iron core 3 and uses a square copper tube for internal water cooling to lower the coil temperature and extend its service life. Insulating bolts 7 are used to fix the iron core 3 between each coil of the coil 4, increasing the deformation resistance of the iron core 3. To reduce heat generation from the insulating bolts 7, an insulating sleeve 8 is fitted over them.

[0043] The iron core facing the water inlet 1 area adopts an arc-shaped iron core structure 5, and a coil 4 is wound on it to maintain the magnetic circuit continuity across the entire cross-section, thereby improving the uniformity and strength of the magnetic field on the cross-section of the billet.

[0044] The crystallizer jacket 2 is where the electromagnetic stirrer is installed on the continuous casting machine. Its load-bearing capacity is limited; when the cross-section of the electromagnetic stirrer exceeds 2150mm, the weight of the stirrer exceeds its bearing capacity, causing deformation. A support beam 6 is designed in the middle of the jacket to improve its load-bearing capacity. To enhance the stirring intensity in the nozzle 1 area, the support beam 6 is made of carbon steel, allowing the magnetic field generated by the electromagnetic stirrer to be introduced into the nozzle 1 area through the support beam 6, increasing stirring in the nozzle 1 area and improving product quality. During operation, the entire electromagnetic stirrer is installed in the crystallizer jacket 2 cavity via flange 9.

[0045] This invention employs an integral iron core design (such as...) Figure 3 As shown, due to its numerous magnetic poles, high magnetic field strength, and uniform distribution of magnetic field strength across its cross-section, the metallurgical effect obtained is optimal.

[0046] In the description of this application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0047] Specific embodiments of the present invention have been described above. It should be understood that the present invention is not limited to the specific embodiments described above, and those skilled in the art can make various changes or modifications within the scope of the claims, which do not affect the essence of the present invention. Unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

Claims

1. An electromagnetic stirring device for slabs of thick plates, characterized in that, Includes an electromagnetic stirring structure; The electromagnetic stirring structure includes: an iron core (3) and a coil (4); The iron core (3) is formed by integral stamping of silicon steel sheets and then stacking them layer by layer; The coil (4) is wound inside the slot of the iron core (3); The iron core (3) is fixed between each coil of the coil (4) by means of insulating bolts (7) passing through it. The part of the iron core (3) facing the water inlet (1) adopts an arc-shaped iron core structure (5), and a coil (4) is wound on the arc-shaped iron core structure (5) to maintain the magnetic circuit continuous and unlayered throughout the entire cross-section.

2. The electromagnetic stirring device for slabs of thick plates according to claim 1, characterized in that, It also includes the crystallizer jacket (2); The electromagnetic stirring structure is installed in the crystallizer jacket (2).

3. The electromagnetic stirring device for slabs of thick plates according to claim 1, characterized in that, The coil temperature is reduced by using a square copper tube with internal water cooling.

4. The electromagnetic stirring device for slabs of thick plates according to claim 1, characterized in that, Insulating bolt (7) with outer insulating sleeve (8).

5. The electromagnetic stirring device for slabs of thick plates according to claim 2, characterized in that, A support beam (6) is set in the middle of the crystallizer jacket (2). The support beam (6) is made of carbon steel so that the magnetic field generated by the electromagnetic stirring is introduced into the water inlet (1) area through the support beam (6).

6. The electromagnetic stirring device for slabs of thick plates according to claim 2, characterized in that, During operation, the entire electromagnetic stirring structure is installed in the cavity of the crystallizer jacket (2) by means of flange (9) connection.

7. The electromagnetic stirring device for slabs of thick plates according to any one of claims 1 to 6, characterized in that, The cross-section of the thick plate exceeds 2150mm.

8. The electromagnetic stirring device for slabs of thick plates according to claim 7, characterized in that, The cross-section of the thick plate is 2150mm-4300mm.

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