JP2010214392A

JP2010214392A - Electromagnetic stirring device

Info

Publication number: JP2010214392A
Application number: JP2009061568A
Authority: JP
Inventors: Toyohiko Kamiyoshi; 豊彦神吉; Koshi Sato; 孔司佐藤
Original assignee: Nippon Steel Engineering Co Ltd
Current assignee: Nippon Steel Engineering Co Ltd
Priority date: 2009-03-13
Filing date: 2009-03-13
Publication date: 2010-09-30

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three phase linear type electromagnetic stirring device in which the capacity of a three phase AC power source is decreased, and the distribution of the stirring force in the longitudinal direction of a linear type iron core is uniformed. <P>SOLUTION: The electromagnetic stirring device 10 has, in the molten steels subjected to continuous casting, a plurality of magnetic poles 13 arranged in parallel, linear type iron cores 14, 15 arranged so as to be confronted, coils of a U phase, a V phase and a W phase coiled around the linear type iron cores 14, 15, and a three phase AC power source with variable frequency feeding three phase electric current to the coil of each phase. The number of turns N<SB>o</SB>of unit coils 16, 19, 22 and 25 at the edge parts respectively arranged at both the edge sides of the linear type iron cores 14, 15 is made larger than the number of turns N<SB>I</SB>of the remaining unit coils 17, 18, 20, 21, 23, 24, 26, 27, and the uniformization of the electric current flowing through the coils of the U phase, the V phase and the W phase is achieved. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

本発明は、連続鋳造設備に設置され、鋳片の未凝固溶鋼を撹拌する３相リニア型の電磁撹拌装置に関する。 The present invention relates to a three-phase linear electromagnetic stirring device that is installed in a continuous casting facility and stirs unsolidified molten steel of a slab.

連続鋳造設備において、鋳片の品質向上を目的として電磁撹拌装置を鋳型部もしくは二次冷却帯部に適用することが広く知られている。そして、電磁撹拌装置のうち、移動磁界を利用する３相リニア型の電磁撹拌装置においては、特許文献１に記載されるように、リニア型鉄心に各相コイルが巻かれた構造のものが一般的である。また、特許文献２には、複数ストランドに適用する場合、各ストランドにおける撹拌力を均一化する目的でコイル群の巻数比をストランド毎に変えることが開示されている。 In a continuous casting facility, it is widely known that an electromagnetic stirring device is applied to a mold part or a secondary cooling zone part for the purpose of improving the quality of a slab. Of the electromagnetic stirring devices, a three-phase linear type electromagnetic stirring device that uses a moving magnetic field generally has a structure in which each phase coil is wound around a linear type iron core as described in Patent Document 1. Is. Patent Document 2 discloses that when applied to a plurality of strands, the winding ratio of the coil group is changed for each strand for the purpose of uniformizing the stirring force in each strand.

特開２００４−４２０６５号公報Japanese Patent Laid-Open No. 2004-42065 特開２００６−２８９４４８号公報JP 2006-289448 A

しかしながら、特許文献１、２に記載された発明では、相互インダクタンスの関係から、リニア型鉄心に巻かれたコイルのうち、リニア型鉄心の両端側にそれぞれ配置される端部のコイルのインピーダンスは、端部のコイルを除いた残りのコイルのインピーダンスより小さくなる。その結果、コイルに３相平衡電源（１２０度ずつ各相の位相がずれて電圧値が等しい電源）を接続して通電した場合、端部のコイルを含む相の電流は大きくなり、端部のコイルを除いた残りのコイルのみを含む相の電流は小さくなる。一方、コイルで発生する磁界による撹拌力は、電源周波数に依存するため、最も強力な撹拌力を得る目的で、電磁撹拌装置の電源はインバータ電源等の周波数可変の３相交流電源が適用されるのが一般的である。ここで、周波数可変の３相交流電源の容量は、３相の電流がバランスしていない場合、最大電流が流れる相の電流の値で決まってしまうため、３相の電流がバランスしていない場合は必要以上に大きな容量の電源を準備する必要があり、設備がコストアップするという問題がある。また、端部のコイルを含む相のコイル電流が大きく、端部のコイルを除いた残りのコイルのみを含む相のコイルの電流が小さいため、結果的に溶鋼に作用する撹拌力のリニア型鉄心の長手方向の撹拌力分布が不均一になり、均一な溶鋼撹拌効果が得られないという問題がある。 However, in the inventions described in Patent Documents 1 and 2, from the mutual inductance relationship, among the coils wound around the linear iron core, the impedance of the end coil respectively disposed on both ends of the linear iron core is: It becomes smaller than the impedance of the remaining coils excluding the end coil. As a result, when a three-phase balanced power source (a power source having an equal voltage value with a phase shift of 120 degrees each) is connected to the coil, the current of the phase including the end coil increases, The current of the phase including only the remaining coils excluding the coils becomes small. On the other hand, since the stirring force due to the magnetic field generated by the coil depends on the power supply frequency, a variable-frequency three-phase AC power source such as an inverter power source is applied as the power source of the electromagnetic stirring device for the purpose of obtaining the strongest stirring force. It is common. Here, the capacity of the three-phase AC power source with variable frequency is determined by the value of the phase current through which the maximum current flows when the three-phase current is not balanced. There is a problem that it is necessary to prepare a power supply having a larger capacity than necessary, which increases the cost of the equipment. In addition, since the coil current of the phase including the end coil is large and the current of the phase coil including only the remaining coil excluding the end coil is small, the linear iron core of the stirring force acting on the molten steel as a result The distribution of the stirring force in the longitudinal direction becomes non-uniform, and there is a problem that a uniform molten steel stirring effect cannot be obtained.

本発明はかかる事情に鑑みてなされたもので、３相のコイルに流れる電流の均一化を図って周波数可変の３相交流電源の容量を小さくすると共に、リニア型鉄心の長手方向の撹拌力分布を均一にすることが可能な３相リニア型の電磁撹拌装置を提供することを目的とする。 The present invention has been made in view of such circumstances, and the current flowing in the three-phase coil is made uniform to reduce the capacity of the variable-frequency three-phase AC power source, and the stirring force distribution in the longitudinal direction of the linear iron core. It is an object of the present invention to provide a three-phase linear electromagnetic stirring device that can make the temperature uniform.

前記目的に沿う本発明に係る電磁撹拌装置は、連続鋳造される溶鋼を間にして、並べて配置される複数の磁極を有し、対向して配置されるリニア型鉄心と、該リニア型鉄心にそれぞれ巻回されたＵ相、Ｖ相、及びＷ相のコイルと、該コイルに３相電流を供給する周波数が可変の３相交流電源とを有する電磁撹拌装置において、
前記リニア型鉄心の両端側にそれぞれ配置される端部の単位コイルの巻き数Ｎ_Ｏを、該端部の単位コイルを除いた残りの単位コイルの巻き数Ｎ_Ｉより多くして、前記コイルに流れる電流の均一化を図っている。
ここで、連続鋳造される溶鋼とは、鋳型部内の溶鋼又は二次冷却帯部を通過する鋳片の中央部に残留する溶鋼を指す。 An electromagnetic stirrer according to the present invention that meets the above-mentioned object has a plurality of magnetic poles arranged side by side with a continuously cast molten steel in between, and a linear type iron core that is arranged oppositely, and the linear type iron core. In an electromagnetic stirrer having a wound U-phase, V-phase, and W-phase coil, and a three-phase AC power source with a variable frequency for supplying a three-phase current to the coil
The number of turns N _O of the end unit coils arranged on both ends of the linear iron core is made larger than the number of turns N _I of the remaining unit coils excluding the end unit coils, and the coils The current flowing is made uniform.
Here, the continuously cast molten steel refers to molten steel in the mold part or molten steel remaining in the center of the slab passing through the secondary cooling zone.

本発明に係る電磁撹拌装置において、前記Ｕ相のコイル、前記Ｖ相のコイル、及び前記Ｗ相のコイルは、いずれも１の単位コイルから又は複数の単位コイルが直列あるいは並列に接続されて構成することができる。 In the electromagnetic stirrer according to the present invention, the U-phase coil, the V-phase coil, and the W-phase coil are all configured from one unit coil or a plurality of unit coils connected in series or in parallel. can do.

本発明に係る電磁撹拌装置において、前記端部の単位コイルの巻き数Ｎ_Ｏに対する前記残りの単位コイルの巻き数Ｎ_Ｉの比Ｎ_Ｏ／Ｎ_Ｉは１．１以上で１．４２以下とすることができる。 In the electromagnetic stirrer according to the present invention, the ratio N _O / N _I of the number N _I of turns of the remaining unit coils to the number N _O of turns of the unit coils at the end is 1.1 or more and 1.42 or less. be able to.

本発明に係る電磁撹拌装置においては、リニア型鉄心の端部の単位コイルの巻き数Ｎ_Ｏを、残りの単位コイルの巻き数Ｎ_Ｉより多くして、各相のコイルに流れる電流の均一化を図るので、電磁撹拌装置の３相交流電源の容量を小さくすることができ、電磁撹拌装置（３相交流電源）のコストダウンが可能になる。また、各相のコイルに流れる電流が均一化することで、溶鋼に作用するリニア型鉄心の長手方向の撹拌力分布が均一になり、均一な溶鋼撹拌流を発生させて円滑な溶鋼撹拌を行うことができる。 In the electromagnetic stirring device according to the present invention, the number of turns N _O of the unit coil at the end of the linear iron core is made larger than the number of turns N _I of the remaining unit coils to equalize the current flowing through the coils of each phase. Therefore, the capacity of the three-phase AC power source of the electromagnetic stirring device can be reduced, and the cost of the electromagnetic stirring device (three-phase AC power source) can be reduced. In addition, since the current flowing through the coils of each phase is made uniform, the distribution of the stirring force in the longitudinal direction of the linear iron core acting on the molten steel becomes uniform, and a uniform molten steel stirring flow is generated to perform smooth molten steel stirring. be able to.

本発明に係る電磁撹拌装置において、Ｕ相のコイル、Ｖ相のコイル、及びＷ相のコイルが、いずれも１の単位コイルから又は複数の単位コイルが直列あるいは並列に接続されて構成される場合、溶鋼撹拌を行う領域の寸法に合わせて最適な電磁撹拌装置を作製できる。 In the electromagnetic stirrer according to the present invention, the U-phase coil, the V-phase coil, and the W-phase coil are all configured from one unit coil or a plurality of unit coils connected in series or in parallel. An optimum electromagnetic stirring device can be produced in accordance with the size of the region where the molten steel is stirred.

本発明に係る電磁撹拌装置において、端部の単位コイルの巻き数Ｎ_Ｏに対する残りの単位コイルの巻き数Ｎ_Ｉの比Ｎ_Ｏ／Ｎ_Ｉが１．１以上で１．４２以下の場合、従来の電磁撹拌装置において、端部の単位コイルを含む相のコイルに流れる電流が、残りの単位コイルを含む相のコイルに流れる電流に対して１．２〜２倍の範囲で大きくても、各相のコイルに流れる電流の均一化を図ることができる。 In the electromagnetic stirrer according to the present invention, when the ratio N _O / N _{I of the} number N _I of remaining unit coils to the number N _O of unit coils at the end is 1.1 or more and 1.42 or less, In the electromagnetic stirring device, the current flowing through the phase coil including the unit coil at the end is larger in a range of 1.2 to 2 times the current flowing through the phase coil including the remaining unit coil. The current flowing through the phase coils can be made uniform.

（Ａ）は本発明の一実施の形態に係る電磁撹拌装置を鋳型部に設置した場合の平面図、（Ｂ）は（Ａ）のＰ−Ｐ矢視断面図である。(A) is a top view at the time of installing the electromagnetic stirring apparatus which concerns on one embodiment of this invention in a casting_mold | template part, (B) is PP sectional drawing of (A). 従来技術に係る電磁撹拌装置の作用を模式的に示す説明図である。It is explanatory drawing which shows typically the effect | action of the electromagnetic stirring apparatus which concerns on a prior art. 本発明の一実施の形態に係る電磁撹拌装置の作用を模式的に示す説明図である。It is explanatory drawing which shows typically the effect | action of the electromagnetic stirring apparatus which concerns on one embodiment of this invention.

続いて、添付した図面を参照しつつ、本発明を具体化した実施の形態につき説明し、本発明の理解に供する。
図１（Ａ）、（Ｂ）に示すように、本発明の一実施の形態に係る電磁撹拌装置１０は、連続鋳造設備で連続鋳造される溶鋼が間に来るように、例えば、鋳型１２を間にして、並べて配置される複数の磁極１３（図１では７つ）を有し、対向して配置されるリニア型鉄心１４、１５と、リニア型鉄心１４に巻回され、対となる２つの単位コイル１６、１７が直列に接続されたＵ相、対となる２つの単位コイル１８、１９が直列に接続されたＶ相、対となる２つの単位コイル２０、２１が直列に接続されたＷ相の計６個の単位コイル１６〜２１と、リニア型鉄心１５に巻回され、対となる２つの単位コイル２２、２３が直列に接続されたＵ相、対となる２つの単位コイル２４、２５が直列に接続されたＶ相、対となる２つの単位コイル２６、２７が直列に接続されたＷ相の計６個の単位コイル２２〜２７と、単位コイル１６〜２７に、１２０度ずつ位相がずれたＵ相、Ｖ相、Ｗ相の３相電流を供給する周波数が可変の３相交流電源（図示せず）とを有している。 Next, embodiments of the present invention will be described with reference to the accompanying drawings for understanding of the present invention.
As shown in FIGS. 1 (A) and 1 (B), an electromagnetic stirring device 10 according to an embodiment of the present invention has, for example, a mold 12 so that molten steel continuously cast by a continuous casting facility is in between. In between, there are a plurality of magnetic poles 13 (seven in FIG. 1) arranged side by side, and the linear type iron cores 14 and 15 arranged opposite to each other, and wound around the linear type iron core 14 to form a pair 2 Two unit coils 16 and 17 are connected in series, a pair of unit coils 18 and 19 are connected in series, a V phase is connected, and two pair of unit coils 20 and 21 are connected in series. A total of six unit coils 16 to 21 of the W phase and a U phase in which two unit coils 22 and 23 that are wound around the linear iron core 15 are connected in series, and two unit coils 24 that form a pair , 25 are connected in series to the V phase, and the two unit coils 26, 27 are paired. The frequency for supplying a total of six unit coils 22 to 27 of W phase connected in series and three phase currents of U phase, V phase, and W phase shifted by 120 degrees to unit coils 16 to 27. It has a variable three-phase AC power source (not shown).

鋳型１２は、平面視して長方形状の空間部が内側に形成されるように、空間部の短辺側で対向して配置される短辺銅板２９、３０と、空間部の長辺側で短辺銅板２９、３０を両側から挟んで対向して配置される長辺銅板３１、３２とを有している。そして、短辺銅板２９、３０はそれぞれ短辺側バックプレート３３、３４により支持され、長辺銅板３１、３２はそれぞれ長辺側バックプレート３５、３６により支持されている。また、リニア型鉄心１４、１５は、長辺側バックプレート３５、３６の背面側で、鋳型１２内に浸漬ノズル３７を介して注入される溶鋼３８の湯面（メニスカス）の下方位置に相当する高さ位置に、リニア型鉄心１４、１５の磁極１３の端面が長辺銅板３１、３２と平行な同一平面上に並ぶように水平配置されている。なお、長辺側バックプレート３５、３６は、例えば、オーステナイト系ステンレス鋼で形成されている。 The casting mold 12 includes short-side copper plates 29 and 30 that are arranged to face each other on the short side of the space portion so that a rectangular space portion is formed on the inside in plan view, and on the long-side side of the space portion. It has long-side copper plates 31 and 32 arranged to face each other with the short-side copper plates 29 and 30 sandwiched from both sides. The short side copper plates 29 and 30 are supported by the short side back plates 33 and 34, respectively, and the long side copper plates 31 and 32 are supported by the long side back plates 35 and 36, respectively. The linear iron cores 14 and 15 correspond to positions below the molten metal surface (meniscus) of the molten steel 38 injected into the mold 12 via the immersion nozzle 37 on the back side of the long side back plates 35 and 36. At the height position, the end faces of the magnetic poles 13 of the linear iron cores 14 and 15 are horizontally arranged so as to be aligned on the same plane parallel to the long side copper plates 31 and 32. The long side back plates 35 and 36 are made of, for example, austenitic stainless steel.

そして、３相交流電流を流したときに、単位コイル１６にＵ相、単位コイル２１に−Ｗ相、単位コイル１８にＶ相、単位コイル１７に−Ｕ相、単位コイル２０にＷ相、単位コイル１９に−Ｖ相、単位コイル２２にＵ相、単位コイル２７に−Ｗ相、単位コイル２４にＶ相、単位コイル２３に−Ｕ相、単位コイル２６にＷ相、単位コイル２５に−Ｖ相の３相交流電流が流れるように、単位コイル１６〜２７が３相交流電源と結線されている。なお、−Ｕ相はＵ相と１８０度位相が異なる交流が流れる相であることを、−Ｖ相はＶ相と１８０度位相が異なる交流が流れる相であることを、−Ｗ相はＷ相と１８０度位相が異なる交流が流れる相であることをそれぞれ表している。 When a three-phase alternating current is passed, the unit coil 16 has a U phase, the unit coil 21 has a -W phase, the unit coil 18 has a V phase, the unit coil 17 has a -U phase, and the unit coil 20 has a W phase. -V phase for coil 19, U phase for unit coil 22, -W phase for unit coil 27, V phase for unit coil 24, -U phase for unit coil 23, W phase for unit coil 26, -V for unit coil 25 The unit coils 16 to 27 are connected to a three-phase AC power source so that a three-phase AC current of the phase flows. The -U phase is a phase in which an alternating current that is 180 degrees different from the U phase flows, the -V phase is a phase in which an alternating current that is 180 degrees different from the V phase is flowing, and the -W phase is a W phase. It represents that the alternating current is different in phase by 180 degrees.

各単位コイル１６〜２７に流れる３相電流の位相変化に伴い、鋳型１２内において、リニア型鉄心１４側では単位コイル１６から単位コイル１９に向けて（リニア型鉄心１４の長手方向に）移動する移動磁界が、リニア型鉄心１５側では単位コイル２２から単位コイル２５に向けて（リニア型鉄心１５の長手方向に）移動する移動磁界がそれぞれ発生する。そして、これらの移動磁界の移動方向は互いに逆方向なので、鋳型１２内には移動磁界の移動する方向（リニア型鉄心１４、１５の長手方向に）に電磁力（撹拌力）が生じ、鋳型１２内の溶鋼３８に矢印の方向に溶鋼撹拌流３９が発生する。 Along with the phase change of the three-phase current flowing through the unit coils 16 to 27, the linear type iron core 14 moves in the mold 12 from the unit coil 16 toward the unit coil 19 (in the longitudinal direction of the linear type iron core 14). A moving magnetic field is generated in which the moving magnetic field moves from the unit coil 22 toward the unit coil 25 (in the longitudinal direction of the linear iron core 15) on the linear iron core 15 side. Since the moving directions of these moving magnetic fields are opposite to each other, an electromagnetic force (agitating force) is generated in the moving direction of the moving magnetic field (in the longitudinal direction of the linear iron cores 14 and 15) in the casting mold 12. A molten steel stirring flow 39 is generated in the molten steel 38 in the direction of the arrow.

ここで、リニア型鉄心１４の両端側にそれぞれ配置される端部の単位コイル１６、１９の巻き数Ｎ_Ｏを、端部の単位コイル１６、１９を除いた残りの単位コイル１７、１８、２０、２１の巻き数Ｎ_Ｉより多くし、リニア型鉄心１５の両端側にそれぞれ配置される端部の単位コイル２２、２５の巻き数Ｎ_Ｏを、端部の単位コイル２２、２５を除いた残りの単位コイル２３、２４、２６、２７の巻き数Ｎ_Ｉより多くしている。 Here, the number of turns N _O of the end unit coils 16 and 19 respectively disposed on both ends of the linear iron core 14 is set to the remaining unit coils 17, 18, and 20 excluding the end unit coils 16 and 19. the remainder was larger than the number of turns _{N I} 21, the number of turns _{N O} unit coils 22 and 25 of the end that is arranged on both end sides of the linear core 15, excluding the unit coils 22 and 25 of the end portion It is larger than the number of turns _{N I} unit coils 23,24,26,27 in.

これにより、相互インダクタンスの影響を受けても、リニア型鉄心１４（１５）にそれぞれ巻かれた単位コイル１６〜２１（２２〜２７）のうち、リニア型鉄心１４（１５）の両端側にそれぞれ配置される端部の単位コイル１６、１９（２２、２５）のインピーダンスと、端部の単位コイル１６、１９（２２、２５）を除いた残りの単位コイル１７、１８、２０、２１（２３、２４、２６、２７）のインピーダンスを均一化することができ、各単位コイル１６〜２１（２２〜２７）に流れる電流の均一化を図ることができる。その結果、リニア型鉄心１４、１５の長手方向の撹拌力分布が均一になり、溶鋼撹拌流３９は均一になって円滑な溶鋼撹拌を行うことができる。 Thereby, even if it receives to the influence of mutual inductance, it arrange | positions at the both ends of the linear type iron core 14 (15) among the unit coils 16-21 (22-27) wound around the linear type iron core 14 (15), respectively. And the remaining unit coils 17, 18, 20, 21 (23, 24) excluding the end unit coils 16, 19 (22, 25). , 26, 27) can be made uniform, and the current flowing through each of the unit coils 16-21 (22-27) can be made uniform. As a result, the distribution of the stirring force in the longitudinal direction of the linear iron cores 14 and 15 becomes uniform, the molten steel stirring flow 39 becomes uniform, and smooth molten steel stirring can be performed.

なお、残りの単位コイル１７、１８、２０、２１（２３、２４、２６、２７）の巻き数Ｎ_Ｉに対する端部の単位コイル１６、１９（２２、２５）の巻き数Ｎ_Ｏの比Ｎ_Ｏ／Ｎ_Ｉは１．１以上で１．４２以下である。このため、各単位コイルが同一の巻き数の場合、相互インダクタンスの影響で端部の単位コイルを含む相のコイルに流れる電流が、残りの単位コイルを含む相のコイルに流れる電流に対して１．２〜２倍の範囲で大きくなっても、端部のコイル１６、１９（２２、２５）の巻き数Ｎ_Ｏを１．１〜１．４２倍だけ大きくすることで、各単位コイル１６〜２１（２２〜２７）に流れる電流の均一化を図ることができる。 The ratio _{N O} number of turns _{N O} unit coils end against the number of turns _{N I} of the remaining unit coils 17,18,20,21 (23,24,26,27) 16,19 (22, 25) / _{N I} is 1.42 or less 1.1 or more. Therefore, when each unit coil has the same number of turns, the current flowing in the phase coil including the unit coil at the end due to the mutual inductance is 1 for the current flowing in the phase coil including the remaining unit coils. Even if it becomes large in the range of 2 to 2 times, by increasing the number of turns N _O of the end coils 16, 19 (22, 25) by 1.1 to 1.42 times, each unit coil 16 to 21 (22-27) can be made uniform.

続いて、本発明の一実施の形態に係る電磁撹拌装置１０を鋳型部に設置した場合の作用について、従来技術と比較しながら説明する。
図２に、従来技術に係る電磁撹拌装置４０に設けられたリニア型鉄心４１を示す。リニア型鉄心４１は、並べて配置される７つの磁極１３ａを有し、リニア型鉄心４１には、対となる２つの単位コイル４２、４３が直列に接続されたＵ相、対となる２つの単位コイル４４、４５が直列に接続されたＶ相、対となる２つの単位コイル４６、４７が直列に接続されたＷ相の計６個の単位コイル４２〜４７が巻回されている。そして、単位コイル４２に３相交流電流のＵ相を流したときに、単位コイル４７に−Ｗ相、単位コイル４４にＶ相、単位コイル４３に−Ｕ相、単位コイル４６にＷ相、単位コイル４５に−Ｖ相の３相交流電流が流れるように、単位コイル４２〜４７が図示しない３相交流電源と結線されている。なお、単位コイル４２〜４７の巻き数はすべて同一である。 Next, the operation when the electromagnetic stirring device 10 according to the embodiment of the present invention is installed in the mold part will be described while comparing with the prior art.
In FIG. 2, the linear type iron core 41 provided in the electromagnetic stirring apparatus 40 which concerns on a prior art is shown. The linear iron core 41 has seven magnetic poles 13a arranged side by side. The linear iron core 41 has a U phase in which two pair of unit coils 42 and 43 are connected in series, and two units in a pair. A total of six unit coils 42 to 47 of the V phase in which the coils 44 and 45 are connected in series and the W phase in which two unit coils 46 and 47 to be paired are connected in series are wound. When the U phase of the three-phase alternating current is passed through the unit coil 42, the unit coil 47 is -W phase, the unit coil 44 is V phase, the unit coil 43 is -U phase, the unit coil 46 is W phase, The unit coils 42 to 47 are connected to a three-phase AC power source (not shown) so that a -V phase three-phase AC current flows through the coil 45. The number of turns of the unit coils 42 to 47 is the same.

各単位コイル４２〜４７の巻き数が同一の場合、相互インダクタンスの影響で、端部の単位コイル４２、４５のインピーダンスが低下し、単位コイル４２、４５をそれぞれ含むＵ相とＶ相のコイルに流れる電流は、残りの単位コイル４６、４７を含むＷ相のコイルに流れる電流に比べて大きくなる。このため、相互インダクタンスの影響を無視して各単位コイル４２〜４７に理論的に流れる電流を１とすると、例えば、単位コイル４２、４３、４４、４５に流れる電流は１．２、単位コイル４６、４７に流れる電流は０．６となる。その結果、Ｕ相とＶ相の単位コイル４２、４３、４４、４５により生じる電磁力による撹拌力が大きく、Ｗ相の単位コイル４６、４７により生じる撹拌力が小さいため、結果的に溶鋼に作用する撹拌力のリニア型鉄心４１の長手方向の撹拌力分布が不均一になり、均一な溶鋼撹拌効果が得られない。 When the number of turns of each of the unit coils 42 to 47 is the same, the impedance of the end unit coils 42 and 45 decreases due to the influence of the mutual inductance, so that the U-phase and V-phase coils including the unit coils 42 and 45 respectively. The flowing current is larger than the current flowing through the W-phase coil including the remaining unit coils 46 and 47. For this reason, assuming that the current that theoretically flows in each of the unit coils 42 to 47 is 1 while ignoring the influence of the mutual inductance, for example, the current that flows in the unit coils 42, 43, 44, 45 is 1.2, and the unit coil 46 , 47 is 0.6. As a result, the stirring force generated by the electromagnetic force generated by the U-phase and V-phase unit coils 42, 43, 44, 45 is large, and the stirring force generated by the W-phase unit coils 46, 47 is small. The distribution of the stirring force in the longitudinal direction of the linear iron core 41 of the stirring force becomes nonuniform, and a uniform molten steel stirring effect cannot be obtained.

一方、図３に示すように、本実施の形態に係る電磁撹拌装置１０に設けられたリニア型鉄心１５では、端部の単位コイル２２、２５の巻き数を、単位コイル２３、２４、２６、２７の巻き数より多くしている（図３の例では、例えば１．２倍としている）。これにより、相互インダクタンスの影響を受けた際に、単位コイル２２、２５のインダクタンスが増大し、結果としてインピーダンスが増大して、すべての単位コイル２２〜２７のインピーダンスが均一化する。その結果、Ｕ相、Ｖ相、Ｗ相の各コイル２２〜２７に流れる電流も均一化し、リニア型鉄心１５の長手方向の撹拌力分布が均一になり、均一な溶鋼撹拌効果が得られる。
そして、従来技術に係る電磁撹拌装置４０に使用する３相交流電源の容量は、最大電流が流れるＵ相（Ｖ相）を流れる電流値で決まるが、本実施の形態に係る電磁撹拌装置１０に使用する３相交流電源の容量は、Ｕ相（Ｖ相、Ｗ相）に流れる電流の値により決まり、電磁撹拌装置１０で使用する３相交流電源の容量を小さくすることができ、電磁撹拌装置（３相交流電源）のコストダウンを図ることができる。 On the other hand, as shown in FIG. 3, in the linear type iron core 15 provided in the electromagnetic stirring device 10 according to the present embodiment, the number of turns of the unit coils 22 and 25 at the end is set to the unit coils 23, 24, 26, More than 27 windings (in the example of FIG. 3, for example, 1.2 times). As a result, when affected by the mutual inductance, the inductances of the unit coils 22 and 25 are increased. As a result, the impedance is increased and the impedances of all the unit coils 22 to 27 are made uniform. As a result, the currents flowing in the U-phase, V-phase, and W-phase coils 22 to 27 are also uniformed, the stirring force distribution in the longitudinal direction of the linear iron core 15 is uniformed, and a uniform molten steel stirring effect is obtained.
And although the capacity | capacitance of the three-phase alternating current power supply used for the electromagnetic stirring apparatus 40 which concerns on a prior art is decided by the electric current value which flows through the U phase (V phase) through which a maximum electric current flows, in the electromagnetic stirring apparatus 10 which concerns on this Embodiment. The capacity of the three-phase AC power source used is determined by the value of the current flowing in the U phase (V phase, W phase), and the capacity of the three phase AC power source used in the electromagnetic stirring device 10 can be reduced. The cost of (three-phase AC power supply) can be reduced.

以上、本発明を、実施の形態を参照して説明してきたが、本発明は何ら上記した実施の形態に記載した構成に限定されるものではなく、特許請求の範囲に記載されている事項の範囲内で考えられるその他の実施の形態や変形例も含むものである。
例えば、本実施の形態では、２個の単位コイルを直列に接続してＵ相、Ｖ相、及びＷ相の各コイルを構成したが、２個の単位コイルを並列に接続してＵ相、Ｖ相、及びＷ相の各コイルを構成することができる。
また、鋳型の寸法に合わせてリニア型鉄心の長さを選定し、リニア型鉄心にそれぞれ巻回するＵ相、Ｖ相、及びＷ相の各単位コイルの個数を１、又は３以上とすることができる。そして、各相の単位コイルの個数を３以上とした場合、３以上の単位コイルは直列に接続しても、並列に接続してもよい。
更に、電磁撹拌装置のリニア型鉄心を、二次冷却帯部において、通過する鋳片に残留する溶鋼を間にして対向して配置することもできる。 As described above, the present invention has been described with reference to the embodiment. However, the present invention is not limited to the configuration described in the above-described embodiment, and the matters described in the scope of claims. Other embodiments and modifications conceivable within the scope are also included.
For example, in the present embodiment, two unit coils are connected in series to configure each of the U-phase, V-phase, and W-phase coils. However, two unit coils are connected in parallel to form a U-phase, V-phase and W-phase coils can be configured.
The length of the linear type iron core is selected according to the dimensions of the mold, and the number of unit coils of U phase, V phase, and W phase wound around the linear type iron core is set to 1 or 3 or more. Can do. When the number of unit coils for each phase is 3 or more, the 3 or more unit coils may be connected in series or in parallel.
Furthermore, the linear iron core of the electromagnetic stirrer can be disposed opposite to the molten steel remaining in the passing slab in the secondary cooling zone.

１０：電磁撹拌装置、１２：鋳型、１３、１３ａ：磁極、１４、１５：リニア型鉄心、１６〜２７：単位コイル、２９、３０：短辺銅板、３１、３２：長辺銅板、３３、３４：短辺側バックプレート、３５、３６：長辺側バックプレート、３７：浸漬ノズル、３８：溶鋼、３９：溶鋼撹拌流、４０：電磁撹拌装置、４１：リニア型鉄心、４２〜４７：単位コイル
10: electromagnetic stirrer, 12: mold, 13, 13a: magnetic pole, 14, 15: linear iron core, 16-27: unit coil, 29, 30: short side copper plate, 31, 32: long side copper plate, 33, 34 : Short side back plate, 35, 36: long side back plate, 37: immersion nozzle, 38: molten steel, 39: molten steel stirring flow, 40: electromagnetic stirring device, 41: linear iron core, 42 to 47: unit coil

Claims

連続鋳造される溶鋼を間にして、並べて配置される複数の磁極を有し、対向して配置されるリニア型鉄心と、該リニア型鉄心にそれぞれ巻回されたＵ相、Ｖ相、及びＷ相のコイルと、該コイルに３相電流を供給する周波数が可変の３相交流電源とを有する電磁撹拌装置において、
前記リニア型鉄心の両端側にそれぞれ配置される端部の単位コイルの巻き数Ｎ_Ｏを、該端部の単位コイルを除いた残りの単位コイルの巻き数Ｎ_Ｉより多くして、前記コイルに流れる電流の均一化を図ることを特徴とする電磁撹拌装置。 A linear iron core having a plurality of magnetic poles arranged side by side with molten steel being continuously cast in between, and a U-phase, a V-phase, and a W wound around the linear iron core, respectively. In an electromagnetic stirrer having a phase coil and a three-phase AC power source with variable frequency for supplying a three-phase current to the coil,
The number of turns N _O of the end unit coils arranged on both ends of the linear iron core is made larger than the number of turns N _I of the remaining unit coils excluding the end unit coils, and the coils An electromagnetic stirrer characterized by equalizing flowing current.

請求項１記載の電磁撹拌装置において、前記Ｕ相のコイル、前記Ｖ相のコイル、及び前記Ｗ相のコイルは、いずれも１の単位コイルから又は複数の単位コイルが直列あるいは並列に接続されて構成されていることを特徴とする電磁撹拌装置。 2. The electromagnetic stirring device according to claim 1, wherein the U-phase coil, the V-phase coil, and the W-phase coil are all connected from one unit coil or a plurality of unit coils in series or in parallel. An electromagnetic stirrer characterized by comprising.

請求項１及び２のいずれか１項に記載の電磁撹拌装置において、前記端部の単位コイルの巻き数Ｎ_Ｏに対する前記残りの単位コイルの巻き数Ｎ_Ｉの比Ｎ_Ｏ／Ｎ_Ｉは１．１以上で１．４２以下であることを特徴とする電磁撹拌装置。 3. The electromagnetic stirring device according to claim 1, wherein a ratio N _O / N _I of the number of turns N _I of the remaining unit coils to the number of turns N _O of the unit coils at the end is 1. An electromagnetic stirrer characterized by being 1 or more and 1.42 or less.