A composite electromagnetic stirrer for stirring liquid metal

Abstract

The utility model discloses a kind of composite electromagnetic stirrers for stirring liquid metal, including inductor shell, traveling wave magnetic field inductor and rotating magnetic field inductor.Inductor shell is composed of inner shell, outer shell and upper and lower end plate. Traveling wave and rotating magnetic field inductor are arranged in shell and partially overlap radially in axial direction. Rotating magnetic field inductor includes coil and iron core with yoke part, tooth part, coil is wound on inwardly extending tooth part;Traveling wave magnetic field inductor is composed of at least one traveling wave generator, each generator includes coil and iron core. The design shortens the axial length of stirrer by radial overlap layout, suitable for narrow space;Extended iron core tooth part improves magnetic field efficiency;Single or complex effect of traveling wave and rotating magnetic field can generate axial, rotating or helical electromagnetic force, thereby improving steel liquid flow and solidification, improving casting blank quality.

Description

Technical Field

[0001] This utility model relates to the field of metallurgical equipment technology, and more specifically, to a composite electromagnetic stirrer for stirring liquid metal. Background Technology

[0002] Electromagnetic stirring technology is one of the key process equipment for improving billet quality in modern continuous casting. In the continuous casting production of square and round billets, applying an electromagnetic field in the crystallizer, secondary cooling zone, or at the end of solidification effectively stirs the unsolidified molten steel within the billet, thereby improving the solidification structure, reducing component segregation, and refining the grain size. Currently, the most widely used electromagnetic stirrer is based on the principle of a rotating magnetic field. It generates a rotating magnetic field around the billet, driving the molten steel to rotate, which plays a positive role in improving the surface and some internal quality of the billet.

[0003] However, traditional rotating magnetic field electromagnetic stirrers generate relatively simple magnetic field patterns, providing only circumferential stirring force. For some high-quality steel grades, especially high-alloy steels, the effectiveness of a single rotating stirring mode in promoting equiaxed grain growth, enhancing central feeding, and effectively eliminating central porosity and shrinkage cavities has reached its limit. To achieve better metallurgical results, those skilled in the art have begun to explore composite electromagnetic stirring technologies capable of generating multiple magnetic field modes, such as combining a traveling wave magnetic field that generates axial stirring force with a rotating magnetic field that generates rotational stirring force, in order to achieve more precise and powerful control over the flow of molten steel.

[0004] The inventors previously proposed a multi-mode electromagnetic stirring device, which independently arranges a traveling wave magnetic field generator and a rotating magnetic field generator along the axial direction within the inductor housing. While this approach achieves the combined effect of the two magnetic fields, the lack of axial overlap between the two generators results in a relatively long axial length for the entire device. In practical industrial applications, the installation space in the secondary cooling zone or at the solidification end of a continuous casting machine is often very limited, significantly restricting the applicability of such a large axially sized device. Therefore, a solution for a composite electromagnetic stirrer that can operate effectively within limited installation space is needed. Utility Model Content

[0005] In view of the above-mentioned technical problems in related technologies, this utility model proposes a composite electromagnetic stirrer for stirring liquid metal, which can overcome the above-mentioned shortcomings of the prior art.

[0006] To achieve the above-mentioned technical objectives, the technical solution of this utility model is implemented as follows: A composite electromagnetic stirrer for stirring liquid metal; Includes sensor housing, traveling wave magnetic field sensor, and rotating magnetic field sensor; The sensor housing includes an inner housing, an outer housing, a lower end plate of the housing, and an upper end plate of the housing. The traveling wave magnetic field sensor and the rotating magnetic field sensor are arranged axially within the sensor housing, and the traveling wave magnetic field sensor and the rotating magnetic field sensor partially overlap in radial space. The rotating magnetic field sensor includes a rotating coil and a rotating iron core. The rotating iron core includes an iron core yoke and a plurality of iron core teeth. The rotating coil is wound on the iron core teeth, and the iron core teeth extend toward the inner housing. The traveling wave magnetic field sensor consists of N traveling wave generators, where N is a natural number greater than or equal to 1, and each traveling wave generator includes a traveling wave coil and a traveling wave core.

[0007] Furthermore, the number of traveling wave coils on each of the traveling wave generators is a multiple of 2 or 3. The traveling wave coils are connected in a star or delta configuration and generate an axial traveling wave magnetic field when connected to two-phase or three-phase AC power.

[0008] Furthermore, the number of rotating coils in the rotating magnetic field sensor is a multiple of 2 or 3. The rotating coils are connected in a star or delta configuration and generate a rotating magnetic field when connected to two-phase or three-phase alternating current.

[0009] Furthermore, the traveling wave coil and the rotating coil are wound with hollow copper tubes or with sintered wire.

[0010] Furthermore, the traveling wave coil of the traveling wave generator is structured as a concentrated short-pitch winding or a cramm winding.

[0011] Furthermore, it also includes a power connector box, which is disposed on the sensor housing, and there are one or more such power connector boxes.

[0012] Furthermore, it also includes inlet and outlet water pipes, which are disposed on the sensor housing, and there are one or more of them.

[0013] The beneficial effects of this invention are as follows: By arranging the traveling wave magnetic field sensor and the rotating magnetic field sensor in a partially overlapping manner in the radial space, the overall axial length of the electromagnetic stirrer is effectively shortened, making it well-suited for industrial applications with limited installation space. Simultaneously, by extending the iron core teeth of the rotating magnetic field sensor, the magnetic field can be more effectively guided to the action area, ensuring full utilization of magnetic field energy within a compact structure. Finally, through the individual or combined action of the traveling wave magnetic field and the rotating magnetic field, controllable electromagnetic forces in axial, rotational, or spiral forms can be generated on the unsolidified molten steel within the billet, effectively improving the flow and solidification process of the molten steel, thereby achieving the goals of increasing the equiaxed crystal ratio, reducing central defects, and improving the internal quality of the continuously cast billet. Attached Figure Description

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 This is a schematic diagram of a composite electromagnetic stirrer for stirring liquid metal according to an embodiment of the present invention; Figure 2 This is a schematic diagram of an embodiment of a multi-mode electromagnetic stirring device proposed by the inventor in the previous work, as described in this utility model embodiment; Figure 3 This is a schematic diagram of the structure of a prior art rotating magnetic field sensor embodiment described in this utility model; Figure 4 This is a schematic diagram of the structure of the rotating magnetic field sensor embodiment described in this utility model; Figure 5 This is a schematic diagram of the structure of the traveling wave generator according to Embodiment 1 of this utility model; Figure 6 This is a schematic diagram of the structure of the traveling wave generator embodiment two described in this utility model.

[0016] In the picture: 1. Sensor housing; 2. Traveling wave magnetic field sensor; 3. Rotating magnetic field sensor; 4. Power connection box; 5. Inlet and outlet water pipes; 6. Continuous casting billet; 11. Inner housing; 12. Outer housing; 13. Lower end plate of housing; 14. Upper end plate of housing; 21. Traveling wave generator; 211. Traveling wave coil; 212. Traveling wave core; 31. Rotating coil; 32. Rotating core; 321. Core yoke; 322. Core teeth. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art are within the protection scope of the present utility model.

[0018] like Figure 1 and Figures 3 to 6As shown, this utility model discloses a composite electromagnetic stirrer for stirring liquid metal, including an inductor housing 1, a traveling wave magnetic field inductor 2, and a rotating magnetic field inductor 3. The inductor housing 1 includes an inner housing 11, an outer housing 12, a lower end plate 13, and an upper end plate 14. The traveling wave magnetic field inductor 2 and the rotating magnetic field inductor 3 are arranged axially within the inductor housing 1, and partially overlap in radial space. The rotating magnetic field inductor 3 includes a rotating coil 31 and a rotating iron core 32. The rotating iron core 32 includes an iron core yoke 321 and multiple iron core teeth 322. The rotating coil 31 is wound around the iron core teeth 322, and the iron core teeth 322 extend toward the inner housing 11. The traveling wave magnetic field inductor 2 is composed of N traveling wave generators 21, where N is a natural number greater than or equal to 1. Each traveling wave generator 21 includes a traveling wave coil 211 and a traveling wave iron core 212. The power connection box 4 is disposed on the sensor housing 1, and there are one or more of them. The water inlet and outlet pipes 5 are disposed on the sensor housing 1, and there are one or more of them. The continuously cast billet 6 passes through the inner housing 11.

[0019] The following is a detailed explanation with reference to the accompanying figures.

[0020] Figure 1 This invention illustrates a composite electromagnetic stirrer for stirring liquid metal, provided by an embodiment of the present invention. The stirrer mainly includes an inductor housing 1, a traveling wave magnetic field inductor 2, a rotating magnetic field inductor 3, a power supply connection box 4, and inlet / outlet water pipes 5. The inductor housing 1 is composed of an inner housing 11, an outer housing 12, a lower end plate 13, and an upper end plate 14. The traveling wave magnetic field inductor 2 and the rotating magnetic field inductor 3 are axially mounted inside the inductor housing 1 and have a partially overlapping area in the radial space. This arrangement helps to reduce the overall axial dimension of the stirrer and is suitable for applications with limited installation space. The rotating magnetic field inductor 3 consists of a rotating coil 31 and a rotating iron core 32. The rotating iron core 32 includes an iron core yoke 321 and multiple iron core teeth 322. The rotating coil 31 is wound around the iron core teeth 322, and the iron core teeth 322 extend towards the inner housing 11 of the inductor to enhance the magnetic field guiding effect and improve the magnetic field utilization rate. The traveling wave magnetic field sensor 2 consists of N traveling wave generators 21 (N is a natural number not less than 1). Each traveling wave generator 21 generates a traveling wave magnetic field along the axial direction inside the sensor housing 1 when energized. A power connection box 4 is located on the sensor housing 1, and there can be one or more of them, used to connect to an external power source. Inlet and outlet water pipes 5 are also located on the sensor housing 1, and there can be one or more sets, used to circulate cooling water to cool the sensor coil and housing.

[0021] The continuously cast billet 6 passes through the inner shell 11. When an alternating current is applied to the traveling wave magnetic field inductor 2, a traveling wave magnetic field is formed inside the agitator, which generates an axial stirring effect on the unsolidified molten steel in the continuously cast billet 6. When an alternating current is applied to the rotating magnetic field inductor 3, a rotating magnetic field is formed, which realizes the rotational stirring of the molten steel. If both are powered at the same time, the traveling wave magnetic field and the rotating magnetic field can be generated simultaneously. The two magnetic fields act together on the molten steel to realize the spiral stirring of the molten steel.

[0022] Figure 2 The image shows a comparative embodiment of a multi-mode electromagnetic stirring device proposed by the inventor in the previous case. In this embodiment, the traveling wave magnetic field sensor 2 and the rotating magnetic field sensor 3 are arranged sequentially along the axial direction within the sensor housing 1, with no radial overlap. The rotating iron core 32 in this embodiment has a conventional structure, and the core teeth 322 are not specially extended, making it suitable for applications with sufficient axial installation space.

[0023] Figure 3 The diagram illustrates a prior art rotating magnetic field sensor structure. The sensor 3 comprises a rotating coil 31 and a rotating iron core 32. The rotating iron core 32 includes a core yoke 321 and multiple core teeth 322, with the coil 31 wound around the core teeth 322. The core teeth 322 are not extended, and the number of rotating coils 31 is a multiple of 2 or 3; the example in the diagram shows 6 coils.

[0024] Figure 4 This is one embodiment of the rotating magnetic field sensor of this utility model. The core teeth 322 of its rotating core 32 have an extended structure, which can more effectively guide the magnetic field to the region near the inner housing 11, thereby improving the efficiency of the magnetic field action. The number of rotating coils 31 is a multiple of 2 or 3; in this example, there are 6.

[0025] Figure 5 This is a specific embodiment of the traveling wave generator 21 of this utility model. The traveling wave generator 21 consists of a traveling wave coil 211 and a traveling wave core 212. The traveling wave coil 211 is wound on the traveling wave core 212 in the form of a Cramer winding. The number of traveling wave coils 211 is a multiple of 2 or 3; the embodiment shown in the figure has 6.

[0026] Figure 6 This is another embodiment of the traveling wave generator 21 of this utility model. In this example, the traveling wave coil 211 adopts a concentrated short-pitch winding structure, and its number is also a multiple of 2 or 3; in this embodiment, there are 4 coils.

[0027] In summary, the beneficial effects of this utility model are as follows: This invention discloses a composite electromagnetic stirrer for stirring liquid metal, comprising an inductor housing, a traveling wave magnetic field inductor, and a rotating magnetic field inductor arranged axially within the inductor housing. The two inductors partially overlap in radial space to shorten the length of the electromagnetic stirrer, thus making it suitable for applications with limited length space. Simultaneously, the iron core teeth of the rotating magnetic field inductor are specially extended to guide the magnetic field closer to the inner housing of the inductor, improving the efficiency of the magnetic field.

[0028] A typical application of this composite electromagnetic stirrer for stirring liquid metal is as follows: it is installed in the secondary cooling zone or solidification end of a continuous casting machine, through which the continuous casting billet passes. A traveling wave magnetic field inductor is supplied with a certain form of alternating current (2-phase or 3-phase), generating a traveling wave magnetic field within the composite electromagnetic stirrer, thus producing an axial force on the unsolidified molten steel within the billet. A rotating magnetic field inductor is supplied with a certain form of alternating current (2-phase or 3-phase), generating a rotating magnetic field within the composite electromagnetic stirrer, thus producing a rotational force on the unsolidified molten steel within the billet. Simultaneously supplying alternating current (2-phase or 3-phase) to both the traveling wave magnetic field inductor and the rotating magnetic field inductor allows for the simultaneous generation of both traveling wave and rotating magnetic fields within the composite electromagnetic stirrer, thereby generating a spiral stirring force on the unsolidified molten steel within the billet. The shape, magnitude, and direction of the stirring force can be adjusted and controlled via a power supply. This invention relates to a composite electromagnetic stirrer for stirring liquid metal, which is suitable for situations where length and space are limited. After use, it can improve the flow of unsolidified molten steel in continuous casting billets, increase feeding force, improve the equiaxed crystal ratio of continuous casting billets, reduce center segregation, alleviate center porosity and shrinkage cavities, and meet the quality requirements of high alloy steel grades.

[0029] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A composite electromagnetic stirrer for stirring liquid metal, characterized in that, It includes a sensor housing (1), a traveling wave magnetic field sensor (2), and a rotating magnetic field sensor (3). The sensor housing (1) includes an inner housing (11), an outer housing (12), a lower end plate (13) and an upper end plate (14). The traveling wave magnetic field sensor (2) and the rotating magnetic field sensor (3) are arranged axially inside the sensor housing (1), and the traveling wave magnetic field sensor (2) and the rotating magnetic field sensor (3) partially overlap in radial space. The rotating magnetic field sensor (3) includes a rotating coil (31) and a rotating iron core (32). The rotating iron core (32) includes an iron core yoke (321) and a plurality of iron core teeth (322). The rotating coil (31) is wound on the iron core teeth (322), and the iron core teeth (322) extend toward the inner housing (11). The traveling wave magnetic field sensor (2) consists of N traveling wave generators (21), where N is a natural number greater than or equal to 1. Each traveling wave generator (21) includes a traveling wave coil (211) and a traveling wave core (212).

2. The composite electromagnetic stirrer for stirring liquid metal according to claim 1, characterized in that, The number of traveling wave coils (211) on each of the traveling wave generators (21) is a multiple of 2 or 3. The traveling wave coils (211) are connected in a star or delta configuration and generate an axial traveling wave magnetic field when connected to two-phase or three-phase AC power.

3. A composite electromagnetic stirrer for stirring liquid metal according to claim 1, characterized in that, The number of rotating coils (31) of the rotating magnetic field sensor (3) is a multiple of 2 or 3. The rotating coils (31) are connected in a star or delta configuration and generate a rotating magnetic field when connected to two-phase or three-phase AC power.

4. A composite electromagnetic stirrer for stirring liquid metal according to claim 1, characterized in that, The traveling wave coil (211) and the rotating coil (31) are wound with hollow copper tubes or with sintered wire.

5. A composite electromagnetic stirrer for stirring liquid metal according to claim 1, characterized in that, The traveling wave coil (211) of the traveling wave generator (21) has a structure of concentrated short-pitch winding or cramm winding.

6. A composite electromagnetic stirrer for stirring liquid metal according to claim 1, characterized in that, It also includes a power connector box (4), which is disposed on the sensor housing (1), and there are one or more of them.

7. A composite electromagnetic stirrer for stirring liquid metal according to any one of claims 1-5, characterized in that, It also includes inlet and outlet water pipes (5), which are disposed on the sensor housing (1), and there are one or more of them.

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