EP0228827A1 - Brassage d'un métal en fusion - Google Patents

Brassage d'un métal en fusion Download PDF

Info

Publication number
EP0228827A1
EP0228827A1 EP86309455A EP86309455A EP0228827A1 EP 0228827 A1 EP0228827 A1 EP 0228827A1 EP 86309455 A EP86309455 A EP 86309455A EP 86309455 A EP86309455 A EP 86309455A EP 0228827 A1 EP0228827 A1 EP 0228827A1
Authority
EP
European Patent Office
Prior art keywords
mould
loops
molten metal
strand
loop
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Withdrawn
Application number
EP86309455A
Other languages
German (de)
English (en)
Inventor
Keith Richard Whittington
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Concast Standard AG
TI Group Services Ltd
Original Assignee
Concast Standard AG
TI Group Services Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Concast Standard AG, TI Group Services Ltd filed Critical Concast Standard AG
Publication of EP0228827A1 publication Critical patent/EP0228827A1/fr
Withdrawn legal-status Critical Current

Links

Images

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

  • This invention relates to the stirring of molten metal.
  • the molten metal is poured into the open top of a cooled copper mould and the metal emerges from the bottom of the mould as a continuous strand.
  • a solidified skin is formed on the metal which contains the still molten core as it emerges from the mould.
  • the invention provides a method of stirring molten metal in an open-topped mould characterised by the steps of pouring molten metal into the top of the mould, cooling the metal as it passes through the mould so that a skin of solidified metal is formed at the walls of the mould and contains the molten metal as it passes downwardly out of the lower end of the mould as a strand containing molten metal, and electromagnetically inducing a magnetic field in the molten metal by placing induction apparatus about the strand adjacent the lower end of the mould, the induction apparatus being arranged to produce a magnetic field which rotates about a vertical axis in said strand and the rotary stirring of the molten metal being arranged to induce motion of the molten metal upwards and downwards from the level of the apparatus.
  • apparatus for stirring molten metal characterised by comprising an electromagnetic transducer formed of three or more closed loops of electrically conductive material located around the vertical axis of the mould, the loops being coupled to the phases of a multi-phasn alternating current supply so that the currents passing through the loops will produce a magnetic field which rotates about the vertical axis of the mould, the loops being positioned below the lower end of the mould to locate around the strand of metal emerging from the mould.
  • each loop is constructed as individual units separable from one another, each loop including an inner portion carrying an electric current derived from a transformer portion including an energising coil radially outwardly located relative to the inner portion and to the vertical axis of the mould.
  • each loop has a transformer portion which carries at least one energising coil, different loops having an energising coil connected to different phases of the multi-phase supply.
  • the loops are of non-ferromagnetic material and the loops are associated with ferromagnetic pole piece means, the pole piece means including a common pole piece member for providing a continuous flux path around the strand,and individual pole members associated with each loop.
  • the common pole piece member may be formed as elements one associated with each loop and separable from each other.
  • Fig. 1 shows a known stirrer for stirring molten metal in a mould.
  • the mould 10 is of a known kind having an open top into which molten metal is poured from a pourer 11.
  • the mould is of copper and is of rectangular, round or of other suitable cross-section.
  • the mould is cooled and the molten metal solidifies at the walls of the mould as it moves downwardly in the mould so as to form a thin skin of solidified metal which surrounds and contains the still molten metal as it emerges from the lower end of the mould as a strand 12.
  • the induction means 13 at the upper end of the mould induces a rotary stirring action about the vertical axis of the mould and the induction means 14 below the lower end of the mould induces a linear stirring action in the up and down direction, as indicated by arrows 15 and 16 respectively in Fig. 1.
  • each stirrer is adapted for a specific mould and a standard construction of stirrer which is more widely usable is difficult to achieve.
  • the stirrer is located relative to the mould in a position in which it is more likely to interfere with operation of the mould.
  • the upper stirring means be located above the mould in order to achieve adequate stirring in the upper region and to overcome problems due to the presence of the copper mould with its high electrical conductivity.
  • a magnetic field rotating about a vertical axis has been produced whereby a magnetic field which penetrates down into the mould is provided.
  • a magnetic field penetrates down into the molten metal to a limited extent and a below mould stirrer is still necessary if adequate stirring of the molten metal is to be achieved.
  • a stirrer 20 is provided at the lower end of the mould 10 and around the strand 12 emerging from the mould.
  • the stirrer 20 is of the kind generating a magnetic field rotating about the vertical axis of the mould
  • movement of the molten metal is generated up into the mould and down into the strand below the stirrer 20.
  • Such movement is indicated by the arrows in Fig. 2.
  • a rotary movement 21 is induced adjacent the stirrer which is directed about the vertical axis of the mould.
  • This movement induces up and down movement above and below the stirrer as indicated at 22 and 23.
  • Such up and down movement in turn induces rotary movements about the vertical axis towards the upper end of the mould at 24 and at a lower part of the strand 12 at 25a. It has been found that by this means stirring movement of the molten metal at a distance from the stirrer of the order of ten times the width of the strand can be induced.
  • each loop is associated with a transformer or energising coil and the transformers are coupled to a multi-phase alternating current supply such that a magnetic field is produced rotating about an axis passing between the conductive elements.
  • loops 25 can be arranged, as shown, immediately below the end of the mould 10 and around the strand 12.
  • the loops 25 are, in this case, four in number and are associated with a square cross-section mould 10.
  • Each loop is made of non-ferromagnetic material with an inner loop element 26, and an outer loop element 27.
  • the inner and outer elements are interconnected with one another by intermediate elements 28 which are common to two loops 25.
  • the energising coils are omitted but, in this arrangement, they would normally be associated with the intermediate elements 28.
  • the inner and outer elements 26 and 27 are formed as continuous members and the inner elements 26 are normally associated with ferromagnetic pole pieces, to be described, to provide a low reluctance flux path, in known manner.
  • FIG. 4 an alternative form of stirrer is shown which, unlike that of Fig. 3, is capable of being withdrawn from a position adjacent the strand (not shown).
  • the stirrer includes four loops 25A, 25B, 25C and 25D formed as separate units, each having an inner loop element 26A and an outer loop element 27A, the loop elements 26A and 27A being joined at their ends by intermediate loop elements 28A and 28B to form individual closed loops.
  • energising or transformer coils 29 are associated with the outer loop elements 27A.
  • the stirrer When in an operative position the stirrer is arranged with the intermediate loop elements 28A and 28B of adjacent loops closely adjacent one another but due to the loops being formed as individual units they may each be withdrawn outwardly in the directions of arrows A in the event of, for example, a break out from the strand 12 and for installation and maintenance purposes.
  • Fig. 5 shows an arrangement of pole pieces which may be used with the stirrer parts of Figs. 3 and 4.
  • the pole piece arrangement includes a continuous pole piece member 30 usually of laminated ferromagnetic material and, in plan view, the strand cross-section ie, in this case, of square shape. Along each aide of the member 30 is located a discrete pole piece element 31, the elements 31 concentrating the magnetic field to cause it to penetrate into the strand.
  • Fig. 6 shows an alternative pole piece arrangement in which a continuous pole piece member 30 is provided which is conveniently attached directly to the lower end of the mould 10 (not shown).
  • the pole piece elements 31 are, in this case, attached to the inner elements 26A of separable loops 32 (only two of which are shown) similar to those of Fig. 4 whereby the loops 32, together with the elements 31, are movable towards and away from the strand (not shown).
  • the continuous pole piece member 30 may be replaced by four separable members 34 one associated with and connected to each associated loop member 32, as shown in Fig. 7.
  • the members 34 are obliquely angled at their ends so that when the loops 32 and, hence, the members 34 are moved to an operational position adjacent the strand, i.e. in the direction of arrows X, the ends come into close proximity to one another to provide a substantially continuous flux path.
  • Each of the members 34 carries a discrete pole piece element 35.
  • bridging pole piece members 37 one at each corner of the strand 12, can be used.
  • Each of the loops 32 carries a pole piece element 38 which together with the bridging members 37 define a substantially continuous flux path around the strand when in an operative position.
  • the loops 32 can be adapted to different sizes of strand 12.
  • the bridging members 37 can overlap the loops 32 to accommodate different sizes.
  • the loops are each associated with energising coils or transformers 29 to generate a magnetic field which rotates about the vertical axis of the strand 12.
  • the coils 29 are connected to a multi-phase alternating current supply and different coils are associated with different phases. In this way the magnetic field induced by the currents is made to rotate about the vertical axis perpendicular to the plane of the loops.
  • Fig. 9 shows one arrangement of the phases in the loops.
  • a two phase supply is used for the four loops 32A, 32B, 32C and 32D.
  • the phases of opposite loops 32A, 32C and 32B, 32D are equal and opposite at any one instant and one pair of opposite loops is of different phase to the other pair of opposite loops.
  • the loops each have two energising coils 29, 29A associated with the loops so that the current is more equally shared.
  • coils of adjacent loops carry part of the current of one phase of the supply and the coils of opposite pairs of loops are of opposite phase.
  • the cross-section of the loops can be reduced compared with the Fig. 9 arrangement for the same magnetic field strength.
  • Slab moulds producing a strand 12" having an elongate rectangular shape, as shown in Fig. 12 can also use an arrangement of separable loops, in this case arranged along opposite sides of the strand 12". As illustrated three loops 40, 41 are arranged along each side of the strand 12" and a three phase supply is advantageously employed in the manner indicated.
  • stirrers described have the advantage of effecting stirring without the need for an additional stirrer and, especially when separable frames defining the loops are used, the stirrer need not be individually constructed for each mould configuration. Moreover the stirrer may be fitted to an existing mould without significant modification of the mould.
  • stirrer Being situated below the mould the stirrer is not subjected to the same problems as above-mould stirrers and, if necessary the stirrer can be withdrawn from adjacent the strand in the event of, for example, a break out of molten metal from the strand.
  • the strand as it emerges from the mould has a thin solidified skin which has a high electrical resistance and a low permeability at the temperatures involved, so that the magnetic field is easily able to penetrate the skin into the molten metal in this region. Moreover the field penetrates directly into the molten metal and does not have to fringe down into the metal as with above-mould stirrers. Thus the current required in the conducting loops may be reduced compared with above-mould stirrers or stirrers in which the flux has to penetrate the copper wall of the mould.
  • the loops require to be cooled during use and water or oil coolant is passed through channels in the loops or through pipes secured to the loops (neither of which is shown).
  • the coils may be housed in stainless steel boxes (not shown) insulated from the loops and coolant may be passed through the boxes to cool the coils.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Continuous Casting (AREA)
EP86309455A 1985-12-19 1986-12-04 Brassage d'un métal en fusion Withdrawn EP0228827A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB8531335 1985-12-19
GB08531335A GB2184674A (en) 1985-12-19 1985-12-19 Stirring of molten metal during continuous casting

Publications (1)

Publication Number Publication Date
EP0228827A1 true EP0228827A1 (fr) 1987-07-15

Family

ID=10590026

Family Applications (1)

Application Number Title Priority Date Filing Date
EP86309455A Withdrawn EP0228827A1 (fr) 1985-12-19 1986-12-04 Brassage d'un métal en fusion

Country Status (3)

Country Link
EP (1) EP0228827A1 (fr)
JP (1) JPS62187552A (fr)
GB (1) GB2184674A (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114309509A (zh) * 2021-09-28 2022-04-12 上海大学 一种立式连铸时空电磁搅拌模式控制方法及其装置

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105935752B (zh) * 2016-07-08 2019-07-23 东北大学 一种控制铸坯中心质量的立式电磁搅拌方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4183395A (en) * 1977-02-03 1980-01-15 Asea Aktiebolag Multi-phase stirrer
GB2061783A (en) * 1979-10-31 1981-05-20 Asea Ab Electromagnetic stirring in continuous casting
GB2077161A (en) * 1980-06-05 1981-12-16 Ti Group Services Ltd Stirring molten metal in a casting mould

Family Cites Families (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3804147A (en) * 1971-03-30 1974-04-16 Etudes De Centrifugation Continuous rotary method of casting metal utilizing a magnetic field
FR2236584B1 (fr) * 1973-05-21 1976-05-28 Siderurgie Fse Inst Rech
JPS5437086B2 (fr) * 1973-07-16 1979-11-13
AT359225B (de) * 1978-03-23 1980-10-27 Voest Alpine Ag Drehfeld-stranggiesskokille
GB2020561B (en) * 1978-04-05 1983-01-12 Asea Ab Continuous casting method
SE410940C (sv) * 1978-04-05 1985-08-29 Asea Ab Forfaringssett for omroring vid strenggjutning
SE430223B (sv) * 1979-11-06 1983-10-31 Asea Ab Forfaringssett for omroring vid strenggjutning
JPS5825852A (ja) * 1981-07-29 1983-02-16 住友重機械工業株式会社 連続鋳造による成品の品質改良方法
GB2109724A (en) * 1981-11-20 1983-06-08 British Steel Corp Improvements in or relating to electromagnetic stirring in the continuous casting of steel
JPS58119445A (ja) * 1982-01-11 1983-07-15 Sumitomo Light Metal Ind Ltd 銅または銅合金の連続的鋳造方法

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4183395A (en) * 1977-02-03 1980-01-15 Asea Aktiebolag Multi-phase stirrer
GB2061783A (en) * 1979-10-31 1981-05-20 Asea Ab Electromagnetic stirring in continuous casting
GB2077161A (en) * 1980-06-05 1981-12-16 Ti Group Services Ltd Stirring molten metal in a casting mould

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN114309509A (zh) * 2021-09-28 2022-04-12 上海大学 一种立式连铸时空电磁搅拌模式控制方法及其装置
CN114309509B (zh) * 2021-09-28 2024-05-14 上海大学 一种立式连铸时空电磁搅拌模式控制方法及其装置

Also Published As

Publication number Publication date
GB8531335D0 (en) 1986-01-29
GB2184674A (en) 1987-07-01
JPS62187552A (ja) 1987-08-15

Similar Documents

Publication Publication Date Title
CA1079796A (fr) Agitateur electromagnetique pour moulage en continu
EP0531286B2 (fr) Confinement lateral de metal liquide a l'aide de champs magnetiques alternatifs horizontaux
US4470448A (en) Electromagnetic stirring
KR100586665B1 (ko) 연속 주조 장치에서의 용융금속의 전자기적 제동장치
US4693299A (en) Continuous metal casting apparatus
EP0228827A1 (fr) Brassage d'un métal en fusion
SE8801983L (sv) Foerfarande foer elektromagnetisk omroerning av metallsmaeltor
US4572673A (en) Treatment of molten materials
GB2077161A (en) Stirring molten metal in a casting mould
GB2079195A (en) Stirring Molten Metal in a Casting Mould
US4454909A (en) Mold stator for electromagnetic stirring
US4842043A (en) Mold stirrer
GB2079196A (en) Stirring Molten Metal in a Casting Mould
BR8502605A (pt) Aparelho de fundicao continua e aperfeicoamento no dito aparelho de fundicao continua
EP0464151A1 (fr) Agitation electromagnetique de metal en fusion dans un moule pendant le moulage
GB2059834A (en) Electromagnetic stirring of liquid metal in continuous casting
US4886109A (en) Movable strand stirrer
JPS56139265A (en) Electromagnetic stirrer in continuous casting plant
JPS5791855A (en) Electromagnetic stirrer in continuous casting facility
Melford Stirring Molten Metal in a Casting Mould
JPS61172668A (ja) 電磁撹拌装置
JPH11132667A (ja) 金属るつぼ

Legal Events

Date Code Title Description
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

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE ES FR GB GR IT LI LU NL SE

RBV Designated contracting states (corrected)

Designated state(s): DE FR GB IT SE

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

18D Application deemed to be withdrawn

Effective date: 19880118

RIN1 Information on inventor provided before grant (corrected)

Inventor name: WHITTINGTON, KEITH RICHARD