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 is related to a device for continuous or semi-continuous casting of metals. It comprises in particular an electromagnetic brake comprising at least two magnetic cores arranged on one side of a mould and attached thereto, and a yoke which is detachably connected to the two magnetic cores and interconnects them.
• Electromagnetic brakes comprise arrangements for generation of a static, magnetic field generated through direct current or a magnetic field generated through permanent magnets or an alternating, low-frequency pulsating magnetic field in the liquid metal in a mould in a device for continuous or semi-continuous casting of metals.
• the movement of the tap jet into the rest of the liquid metal is retarded by the field and the tap jet is split such that its impulse is weakened or ceases.
• the field of the invention includes in particular devices for casting of "slabs", where the mould has a rectangular cross section and opposite pairs of magnetic cores are arranged along the opposite long sides of the mould and connected to a yoke each.
• each magnetic core is divided into a front part being permanently arranged at the mould and a back part being detachably connected to the front part.
• Each back core part carries a coil and each of the coils is wound substantially parallel to the mould wall around the back magnetic core part.
• the front part of the magnetic core can have the shape of a plate or similar comprising a magnetic material and being permanently connected to the mould.
• the back part has a surface for abutment against the front part which has an area and a geometry which is adjusted to the area and the geometry of the front part which in its turn is depending on the size of the mould among other things.
• Prior art magnetic cores in addition take up a relatively large space in a direction perpendicularly out from the mould wall.
• the object of the invention is achieved by means of a device of the initially defined kind, being characterized in that the yoke carries a coil and that the coil is wound around the yoke substantially between the two magnetic cores interconnected by the yoke.
• the placement of the coil on the yoke results in that some magnetic core parts do not need to carry any coil and be limited by the coil in the same way as with prior art devices. They can easily be extended or shortened in the longitudinal direction of the yoke, that is along the width of the mould.
• the mould is preferably rectangular transversal to the casting direction and has two opposite long sides, along one of which the yoke extends substantially parallel thereto, and the coil is preferably wound around the yoke such that the centre axis of the coil is substantially parallel to said long side and extends perpendicularly to the casting direction in the mould.
• the coil, or the part of the yoke around which the coil is wound can be made easily accessible and exchangeable but can also give access to devices placed under the brake, for instance lifting devices.
• the magnetic cores are arranged with a space therebetween, the coil being positioned substantially right in front of said space. The coil can with advantage be allowed to push into said space in order to save space.
• the yoke comprises a portion, which is detachable from the rest of the yoke and carries the coil.
• the yoke comprises two yoke parts, arranged on opposite sides of said portion, forming a cradle in which said yoke portion can rest and having a surface each adapted to abut against a respective magnetic core.
• the cradle defined by said yoke parts is preferably arranged to allow a displacement of the coil carrying portion substantially vertically out of said cradle in order to facilitate exchange and maintenance of the coil or parts of the device being located vertically under the coil and which would otherwise be hard to access.
• the yoke parts which are arranged on opposite sides of the coil carrying yoke portion can easily be adjusted to different mould widths, or more particularly magnetic core widths, by ad- justment of their length.
• a further object of the invention is to provide a yoke, which is constructed such that the electromagnetic brake can easily be adjusted to different mould widths without the coil or the coils arranged on the brake constituting any substantial obstacle of such an adjustment. Furthermore, the yoke shall be designed according to a principle, which favours a very little space consuming construction of the electromagnetic brake of which the yoke is a part.
• a yoke according to the preamble of patent claim 13, which is characterized in that it carries a coil being wound around the yoke substantially between said surfaces. Said surfaces are two separate surfaces of the yoke which are adapted to detachably abut against one magnetic core each of two magnetic cores arranged at a mould.
• the yoke is moreover preferably arranged and designed in the way described above with reference to the device according to the invention.
• Fig 3 is a schematic, cross section view according to Ill-Ill in Fig 2 and
• Fig 4 is a schematic, cross section view according to IV-IV in Fig 2.
• Fig 1 shows a prior art device for continuous or semi-continuous casting of metals, the device comprising an electromagnetic brake 1.
• the device furthermore comprises a copper mould 2 of a kind known per se on opposite sides of which the electromag- netic brake 1 is arranged.
• the electromagnetic brake 1 comprises a number of magnetic cores 3, 4, 5, 6 connected to the mould wall.
• the magnetic cores 3-6 are arranged in pairs on opposite sides of the mould along the long sides 7, 8 thereof and cover substantially the entire width of the mould except for a centre portion of the mould.
• the magnetic cores 3, 4 and 5, 6, respectively, of each magnetic core pair are connected by means of a yoke 9, 10.
• the magnetic cores 3, 4 and 5, 6, respectively, are welded into windows in so called backup plates 11 , 12 made from stainless steel and forming support walls for the copper sheets of the mould.
• Figs 2-4 show an embodiment of the device according to the invention, which shows an improved further development of the device according to Fig 1.
• the device according to the invention comprises an electromagnetic brake 24, comprising two pairs of magnetic cores 25, 26 and 27, 28, respectively, arranged along opposite long side walls 29, 30 of a copper mould 31 known per se.
• the magnetic cores 25-28 are arranged in a way corresponding to Fig 1 and serve to contribute to a generation of a magnetic field similar to the one described for the device according to Fig 1.
• the magnetic cores are not divided into front and back parts, where the back parts carry coils, which is the case in Fig 1.
• each magnetic core pair are connected by means of a yoke 32, 33.
• Each yoke 32, 33 comprises a portion 34, 35, on which a coil 36, 37 is wound, each such portion being positioned substantially right in front of a space between the two magnetic cores 25, 26 and 27, 28, respectively, interconnected by the yokes 36, 37.
• the yokes are detachably connected to the magnetic cores.
• the yokes 32, 33 On opposite sides of the coil carrying portion 34, 35, the yokes 32, 33 comprise two further parts 38, 39 and 40, 41 , respectively, forming a cradle for the coil carrying portion 34, 35 and having surfaces 46-49 for abutment against the respective magnetic cores 25-28.
• the coil carrying portions 34, 35 are detachably attached, here fastened by bolts from above, to the further parts 38, 39 and 40, 41 , respectively.
• the cradle defined by the further parts 38, 39 and 40, 41 is such that it allows displacement of the coil carrying portions 34, 35 substantially vertically upwards. In that way the coils 36, 37 can be easily dismounted and exchanged if required.
• the coil carrying portions 34, 35 can have the shape of a circular or square bar of magnetic material, around which the coils 36, 37 are wound.
• the yokes 32, 33 furthermore comprise a number of pivoted portions 42-45, here being arranged to be pivoted substantially horizontally to enable access of parts of the device being situated under the electromagnetic brake 24 and which may need to be accessed for exchange and maintenance.
• the pivoted parts 42-45 form part of the parts 38-41 described above which are arranged on opposite sides of the coil carrying portions 34, 35 and connected thereto.
• Typical parts included in the device and situated under the electromagnetic brake 24 and which must be made accessible are for instance lifting devices for lifting the mould with under- lying segments, and parts requiring exchange and maintenance, for instance cylinders which are used for control of the metal string being continuously cast by means of the device.
• the yokes 32, 33 could comprise further parts or portions, but the proposed solution is sufficient for enabling a fast and simple adjustment of the yoke size to different mould widths, that is magnetic core widths.
• the coil carrying portions 34, 35 have a standard size and the length of the further parts 38-41 is adjusted with reference to the width of the mould/magnetic core.
• the yokes 32, 33 preferably have the shape of bars or plates.
• the coil carrying portions 34, 35 can be supplied separately to a user of a device for continuous or semi-continuous casting of metals, who then easily cuts and shapes the further parts 38-41 himself from a suitable bar material.
• the yokes 32, 33, the magnetic cores 25-28 and the coils 36, 37 are arranged to generate a static magnetic field generated through direct current or a magnetic field generated through permanent magnets or an alternating, low-frequency pulsating magnetic field in the liquid metal in the mould of the device.
• Yokes and magnetic cores are all made of a magnetic material, preferably iron.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Continuous Casting (AREA)
• Braking Arrangements (AREA)

Applications Claiming Priority (3)

Publications (2)

Family

ID=20416873

Family Applications (1)

Country Status (7)

Families Citing this family (4)

Family Cites Families (5)

• 1999
  • 1999-09-03 SE SE9903146A patent/SE515990C2/sv not_active IP Right Cessation
• 2000
  • 2000-08-22 EP EP00957185A patent/EP1214165B1/de not_active Expired - Lifetime
  • 2000-08-22 AU AU68838/00A patent/AU6883800A/en not_active Abandoned
  • 2000-08-22 JP JP2001521490A patent/JP2003508229A/ja active Pending
  • 2000-08-22 CA CA002382417A patent/CA2382417A1/en not_active Abandoned
  • 2000-08-22 DE DE60016255T patent/DE60016255T2/de not_active Expired - Lifetime
  • 2000-08-22 WO PCT/SE2000/001598 patent/WO2001017713A1/en active IP Right Grant

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events