EP0374563A1 - Electromagnetic stirrer for continuous casting - Google Patents
Electromagnetic stirrer for continuous casting Download PDFInfo
- Publication number
- EP0374563A1 EP0374563A1 EP19890122320 EP89122320A EP0374563A1 EP 0374563 A1 EP0374563 A1 EP 0374563A1 EP 19890122320 EP19890122320 EP 19890122320 EP 89122320 A EP89122320 A EP 89122320A EP 0374563 A1 EP0374563 A1 EP 0374563A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- iron core
- damping plate
- phase
- coils
- stirrer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22D—CASTING OF METALS; CASTING OF OTHER SUBSTANCES BY THE SAME PROCESSES OR DEVICES
- B22D11/00—Continuous casting of metals, i.e. casting in indefinite lengths
- B22D11/10—Supplying or treating molten metal
- B22D11/11—Treating the molten metal
- B22D11/114—Treating the molten metal by using agitating or vibrating means
- B22D11/115—Treating the molten metal by using agitating or vibrating means by using magnetic fields
Definitions
- the present invention relates to an electromagnetic stirrer for continuous casting according to the precharacterising part of claim 1.
- the present invention aims to provide a solution to the above problem and other problems associated therewith.
- the invention suggests an electromagnetic stirrer for continuous casting according to the introductor part of claim 1, which is characterized by the features of the characterizing part of claim 1.
- the iron core and the damping plate are built in a circle or in a rectangle or in a square so as to form a closed or partially closed magnetic circuit and - with respect to the damping plate - a closed electric circuit.
- the damping plate can sometimes be divided into several parts, separated by air gaps (interruptions), which is also possible with the iron core thus obtaining a partially closed electric circuit for eddy currents in the damping plate and a partially closed magnetic circuit, respectively.
- a coil-wound stirrer can be used, especially in mould stirrers in which the stirrer is built into a mechanical iron structure. A considerably increased efficiency is obtained with such a stirrer design.
- the coils can be arranged to surround the iron core, possibly also the damping plate, and be supplied from a single-phase, two-phase, three-phase, or multi-phase a.c. source.
- the invention can be applied to continuous casting plants for billets and blooms (from 60 mm square up to about 400 x 600 mm), the frequency being 2-20 Hz.
- ⁇ is the resistivity of the damping plate material
- ⁇ 2nf (angular frequency) and ⁇ x ⁇ o the permeability.
- the material in the damping plate is copper, silver, or an alloy of any of these metals.
- the coils 1 are pairwise connected in opposition to each other (R- and R+, S- and S+, T- and T+; see, i.a., at 1 (R+)).
- the direction of the magnetic field is shown at the arrows in the iron core 2.
- the iron core is here an undivided, circular iron core, but it may also be with interruptions.
- the coils 1 surround the iron core 2 but may also surround the surrounding damping plate 3 along with the core (see Figure 3). As will be seen in Figure 1, the coils consist of a number of sub-coils 1 (R, S, T + and -).
- the damping plate 3 has a thickness of at least one-third of' the penetration depth ⁇ and is made of an electrically highly conductive metal, such as copper or silver or an alloy of any of these metals.
- Figure 2 shows a rectangular stirrer supplied with two-phase current (R+ and R-, S+ and S-).
- the iron core 5 is square-shaped, but it may also be rectangular-shaped and may possibly be provided with interruptions.
- a coil is here shown on each leg of the square iron core 5 which is surrounded by a similarly square damping plate 6. Also this damping plate may be provided with interruptions and is to be made of electrically conducting material, such as silver or copper (see above).
- Figure 3 shows a circular stirrer in which the coils 7 surround both the iron core 2 and the damping plate 3.
- the damping plate may be provided with interruptions or air gaps so that the stirrer can be constructed from several sub-stirrers, which, inter alia, facilitates the mounting.
- the stirrers are preferably of a coil-wound kind but may, of course, also be formed with a different winding.
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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Continuous Casting (AREA)
Abstract
Electromagnetic stirrer for continuous casting, comprising at least ore iron core (2) provided with a number of coils (1). The iron core is provided with a damping plate (3) of electrically conducting material, forming a closed magnetic circuit, intended to damp the propagation of the magnetic field in the direction in which the damping plate is placed in relation to the iron core (1, 2).
Description
- The present invention relates to an electromagnetic stirrer for continuous casting according to the precharacterising part of claim 1.
- In continuous casting, especially in continuous casting moulds in which a stirrer is arranged to stir the liquid parts of the cast strand, a problem arises in that part of the magnetic field takes its path through the iron structure of the surrounding mould or the continuous casting machine. This may result in difficulties in obtaining a sufficient stirring power from the stirrer.
- The present invention aims to provide a solution to the above problem and other problems associated therewith.
- To achieve this goal the invention suggests an electromagnetic stirrer for continuous casting according to the introductor part of claim 1, which is characterized by the features of the characterizing part of claim 1.
- Further developments of the invention are characterized by the features of the additional claims. By damping the field leaking out and directing it towards the interior of the stirring region, a greater part of the available magnetic field can be utilized for stirring purposes.
- In a preferred embodiment the iron core and the damping plate are built in a circle or in a rectangle or in a square so as to form a closed or partially closed magnetic circuit and - with respect to the damping plate - a closed electric circuit.
- However, the damping plate can sometimes be divided into several parts, separated by air gaps (interruptions), which is also possible with the iron core thus obtaining a partially closed electric circuit for eddy currents in the damping plate and a partially closed magnetic circuit, respectively.
- A coil-wound stirrer can be used, especially in mould stirrers in which the stirrer is built into a mechanical iron structure. A considerably increased efficiency is obtained with such a stirrer design.
- The coils can be arranged to surround the iron core, possibly also the damping plate, and be supplied from a single-phase, two-phase, three-phase, or multi-phase a.c. source.
- The invention can be applied to continuous casting plants for billets and blooms (from 60 mm square up to about 400 x 600 mm), the frequency being 2-20 Hz.
- The damping plate should have a thickness of at least one-third of the depth of penetration, which is defined as
- By way of example, the invention will now be described in greater detail with reference to the accompanying drawings showing in
- Figure 1 a circular mould stirrer,
- Figure 2 a rectangular mould stirrer, and
- Figure 3 an alternative to Figure 1.
- The coils 1 are pairwise connected in opposition to each other (R- and R+, S- and S+, T- and T+; see, i.a., at 1 (R+)). The direction of the magnetic field is shown at the arrows in the iron core 2. The iron core is here an undivided, circular iron core, but it may also be with interruptions.
- The coils 1 surround the iron core 2 but may also surround the surrounding damping plate 3 along with the core (see Figure 3). As will be seen in Figure 1, the coils consist of a number of sub-coils 1 (R, S, T + and -).
- The damping plate 3 has a thickness of at least one-third of' the penetration depth δ and is made of an electrically highly conductive metal, such as copper or silver or an alloy of any of these metals. By the influence of the damping plate 3, the undesired outwardly protruding part of the magnetic field from the iron core 2 is dampened by the damping plate and thus deflected towards the interior of the cast strand.
- Figure 2 shows a rectangular stirrer supplied with two-phase current (R+ and R-, S+ and S-). Here the
iron core 5 is square-shaped, but it may also be rectangular-shaped and may possibly be provided with interruptions. A coil is here shown on each leg of thesquare iron core 5 which is surrounded by a similarly square damping plate 6. Also this damping plate may be provided with interruptions and is to be made of electrically conducting material, such as silver or copper (see above). - For the rectangular mould stirrer according to Figure 2, the field is shown at the moment when the R-phase has maximum current and the S-phase zero current (90° phase angle).
- Figure 3 shows a circular stirrer in which the coils 7 surround both the iron core 2 and the damping plate 3. The damping plate may be provided with interruptions or air gaps so that the stirrer can be constructed from several sub-stirrers, which, inter alia, facilitates the mounting.
- The stirrers are preferably of a coil-wound kind but may, of course, also be formed with a different winding.
- The stirrer according to the invention may be varied in many ways within the scope of the appended claims.
Claims (9)
1. Electromagnetic stirrer for continuous casting comprising at least one iron core (2;5) provided with a number of coils (1), characterized in that the iron core (2;5) is provided with a damping plate (3;6) of electrically conducting material, forming a closed magnetic circuit, intended to damp the propagation of the magnetic field in the direction in which the damping plate (3) is placed in relation to the iron core (2).
2. Stirrer according to claim 1, characterized in that the damping plate surrounds the iron core in such a way that the radially outwardly protruding portions of the magnetic field are subjected to dampening.
3. Stirrer according to claim 1 or 2, characterized in that the iron core and the damping plate are constructed in a circle or a rectangle or a square so as to form, respectively, a closed or partially closed magnetic circuit and a closed magnetic circuit.
4. Stirrer according to any of the preceding claims, characterized in that the stirrer coil is built up of several sub-coils and composed such that the iron core forms a closed or partially closed magnetic circuit with small air gaps between the sub-coils and that the damping plate or plates is or are formed with interruptions between the sub-coils.
5. Stirrer according to and of the preceding claims, characterized in that the coils are arranged to surround the iron core and are supplied from a single-phase, two-phase, three-phase, or multi-phase a.c. source.
6. Stirrer according to.any of the preceding claims, characterized in that the coils are arranged to surround the iron core and the damping plate and are supplied from single-phase, two-phase, three-phase, or a multi-phase a.c. source.
7. Stirrer according to any of the preceding claims, characterized in that the damping plate is made of copper or silver or an alloy of any of these materials.
8. Stirrer according to any of the preceding claims, characterized in that the thickness of the damping plate is at least one-third of the depth of penetration at a chosen frequency of the a.c. supply source.
9. Stirrer according to any of the preceding claims, characterized in that it is arranged in or at a continuous casting mould.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE8804423 | 1988-12-07 | ||
SE8804423A SE466586B (en) | 1988-12-07 | 1988-12-07 | ELECTROMAGNETIC MOVER BEFORE STRING |
Publications (1)
Publication Number | Publication Date |
---|---|
EP0374563A1 true EP0374563A1 (en) | 1990-06-27 |
Family
ID=20374169
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP19890122320 Withdrawn EP0374563A1 (en) | 1988-12-07 | 1989-12-04 | Electromagnetic stirrer for continuous casting |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP0374563A1 (en) |
JP (1) | JPH02182358A (en) |
SE (1) | SE466586B (en) |
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100450668C (en) * | 2006-07-07 | 2009-01-14 | 湖南中科电气股份有限公司 | Electromagnetic mixing roller of two cool areas of highfield unburnt earthenware |
WO2011057426A1 (en) * | 2009-11-12 | 2011-05-19 | 湖南中科电气股份有限公司 | Electromagnetic stirring roller with high magnetic field for secondary cooling region of plate blank |
WO2020052794A1 (en) | 2018-09-10 | 2020-03-19 | Ergolines Lab S.R.L. | Electromagnetic stirring device in a mould for casting aluminium or aluminium alloys, stirring method in a mould for casting aluminium or aluminium alloys, mould and casting machine for casting aluminium or aluminium alloys |
Families Citing this family (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPH06182512A (en) * | 1992-12-17 | 1994-07-05 | Kobe Steel Ltd | Electromagnetic stirrer in mold |
WO2022249996A1 (en) * | 2021-05-27 | 2022-12-01 | 株式会社 ヂーマグ | Molten metal stirring device and continuous casting system |
JP2023026973A (en) | 2021-08-16 | 2023-03-01 | 株式会社ヂーマグ | Molten metal driving device, molten metal stirring system, molten metal conveyance system, continuous casting system, and molten metal driving method |
Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2759035A (en) * | 1953-08-11 | 1956-08-14 | All Na Svenska Elek Ska Aktieb | Polyphase stirring winding |
US4294304A (en) * | 1976-06-14 | 1981-10-13 | Cem - Compagnie Electro-Mecanique | Electromagnetic centrifuging inductor for rotating a molten metal about its casting axis |
-
1988
- 1988-12-07 SE SE8804423A patent/SE466586B/en not_active IP Right Cessation
-
1989
- 1989-12-04 EP EP19890122320 patent/EP0374563A1/en not_active Withdrawn
- 1989-12-05 JP JP31450589A patent/JPH02182358A/en active Pending
Patent Citations (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US2759035A (en) * | 1953-08-11 | 1956-08-14 | All Na Svenska Elek Ska Aktieb | Polyphase stirring winding |
US4294304A (en) * | 1976-06-14 | 1981-10-13 | Cem - Compagnie Electro-Mecanique | Electromagnetic centrifuging inductor for rotating a molten metal about its casting axis |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN100450668C (en) * | 2006-07-07 | 2009-01-14 | 湖南中科电气股份有限公司 | Electromagnetic mixing roller of two cool areas of highfield unburnt earthenware |
WO2011057426A1 (en) * | 2009-11-12 | 2011-05-19 | 湖南中科电气股份有限公司 | Electromagnetic stirring roller with high magnetic field for secondary cooling region of plate blank |
WO2020052794A1 (en) | 2018-09-10 | 2020-03-19 | Ergolines Lab S.R.L. | Electromagnetic stirring device in a mould for casting aluminium or aluminium alloys, stirring method in a mould for casting aluminium or aluminium alloys, mould and casting machine for casting aluminium or aluminium alloys |
CN112689543A (en) * | 2018-09-10 | 2021-04-20 | 麦角灵实验室公司 | Electromagnetic stirring device for casting moulds for casting aluminium or aluminium alloys, stirring method for casting moulds for casting aluminium or aluminium alloys, moulds and casting machine for casting aluminium or aluminium alloys |
US11612931B2 (en) | 2018-09-10 | 2023-03-28 | Ergolines Lab S.R.L. | Electromagnetic stirring device in a mould for casting aluminium or aluminium alloys, stirring method in a mould for casting aluminium or aluminium alloys, mould and casting machine for casting aluminium or aluminium alloys |
Also Published As
Publication number | Publication date |
---|---|
SE466586B (en) | 1992-03-09 |
SE8804423L (en) | 1990-06-08 |
JPH02182358A (en) | 1990-07-17 |
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Legal Events
Date | Code | Title | Description |
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PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
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AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): DE FR GB IT |
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17P | Request for examination filed |
Effective date: 19901112 |
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17Q | First examination report despatched |
Effective date: 19911021 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN |
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18D | Application deemed to be withdrawn |
Effective date: 19920701 |