US3900695A - Electric induction furnace - Google Patents

Electric induction furnace Download PDF

Info

Publication number
US3900695A
US3900695A US470604A US47060474A US3900695A US 3900695 A US3900695 A US 3900695A US 470604 A US470604 A US 470604A US 47060474 A US47060474 A US 47060474A US 3900695 A US3900695 A US 3900695A
Authority
US
United States
Prior art keywords
copper
coil
aluminum
layer
conductor
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.)
Expired - Lifetime
Application number
US470604A
Other languages
English (en)
Inventor
Conny Andersson
Bertil Hanas
Torsten Korsell
Jan Nilsson
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.)
ABB Norden Holding AB
Original Assignee
ASEA AB
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 ASEA AB filed Critical ASEA AB
Application granted granted Critical
Publication of US3900695A publication Critical patent/US3900695A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F5/00—Coils
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/007—Hydrostatic extrusion
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
    • B21C—MANUFACTURE OF METAL SHEETS, WIRE, RODS, TUBES, PROFILES OR LIKE SEMI-MANUFACTURED PRODUCTS OTHERWISE THAN BY ROLLING; AUXILIARY OPERATIONS USED IN CONNECTION WITH METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL
    • B21C23/00—Extruding metal; Impact extrusion
    • B21C23/22—Making metal-coated products; Making products from two or more metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
    • H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
    • H01B1/02—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors mainly consisting of metals or alloys
    • H01B1/026—Alloys based on copper
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B6/00—Heating by electric, magnetic or electromagnetic fields
    • H05B6/02—Induction heating
    • H05B6/36—Coil arrangements
    • H05B6/367—Coil arrangements for melting furnaces

Definitions

  • An electric induction furnace has an inductor coil formed from a tubular conductor through which cooling water may be flowed, and which is made with an inner layer of corrosion-resisting copper or copper alloy and an outer layer of aluminum or aluminum alloy and which, although oxidizable in air, forms an electrically non-conductive oxide layer eliminating the risk of short-circuiting between the coil convolutions, Material costs are reduced by making the aluminum layer considerably thicker than the copper layer.
  • An electric induction furnace conventionally comprises a crucible for containing a metal melt and an electric induction coil for inductively heating a melt in the crucible.
  • the coil is a coiled tubular conductor through which a cooling liquid can be flowed.
  • the tubular conductor has been made entirely of copper or possibly a copper alloy. This has been done not only because of the high electrical conductivity of copper, but also because of its resistance to corrosion, the cooling water passed through the tubular conductor sometimes being of a generally corrosive nature.
  • the object of the present invention is to provide an electric furnace inductor coil having the advantage of copper and aluminum combined.
  • the furnace with an inductor coil made from a tubular conductor having inner and outer metal layers, the inner layer being a copper or suitable copper alloy and the outer layer being made of some other metal which is substantially free from copper; specifically, the outer layer is made from aluminum or one of the aluminum alloys having high electrical conductivity.
  • This outer layer is made substantially thicker than the inner layer to reduce the materials cost, and therefore carries the majority of the current. the inner layer. with its good corrosion resistance, representing only about 7 to 20 percent of the total metal area of the tubular conductor.
  • This multi-layer tubular conductor may be made by the hydrostatic extrusion method, using conventional techniques, so that the interfaces of the two layers are integrated to a degree resulting in negligible electrical resistance between the two layers, thus substantially eliminating the possibility of coil-overheating due to such resistance should it be present.
  • FIG. I is a vertical section showing conventional tubular product extrusion equipment
  • FIG. 2 is a cross section of the conductor
  • FIG. 3 shows the induction furnace using the coil of this invention.
  • the furnace coil tubular conductor is shown as defining the interior water channel 11 with a round section and having the layer or liner conductor 12 made of copper or a copper alloy, outside of which is the tubular conductor 13 made of aluminum or a suitable aluminum alloy.
  • the inner layer 12, if made of copper alloy, should, of course, be suitably corrosion-resistant; in certain cases a layer of bronze or brass may be used.
  • the copper or copper alloy inner conductor layer should not make up more than from 7 to 20 percent of the total metal area since its presence is required only to resist the corrosion and possible ero sion due to the flowing of the cooling water through the inside or channel 11.
  • the cross sectional contour of the two layers may be the same; for example, they may both be circular or have some other suitable shape.
  • the thicker outer layer made of aluminum or aluminum alloy may have a different external shape than that of the inner layer providing the interfaces of the two layers are the same shape.
  • FIG. 2 shows the outer layer as having a rectangular outer contour with rounded corners, although such outside contour could also be oval or polygonal.
  • the multi-layer coil conductor by the hydrostatic extrusion process.
  • This permits the production of the conductor in a relatively inexpensive manner and assures a substantially resistance-free integration of the interfaces.
  • the connection is substantially metallurgical in character, having the effect of compression welding.
  • the differing conductor contours previously referred to may be effected without difficulty.
  • the hydrostatic extrusion process is well known, and anyone unfamiliar with it may refer to the combined teachings of British patent specification No. 1,240,154 and British patent specification No. 1,227,154.
  • FIG. I shows an example of the above.
  • a billet having a central copper tube I5 and an aluminum tube I6 concentric with the copper tube have their upper ends sealed by an end piece 17, using an elastic sealing sleeve I8, this entire workpiece being placed in the high pressure cylinder 19 of a hydrostatic press.
  • a mandrel 20 is positioned inside of the copper tube 15 and the bottom of the cylinder [9 contains a die 21 having a convergingly conical die orifice.
  • the mandrel is supported by a tubular support 22 surrounding the combination to be extruded, and having ports 23.
  • the hydrostatic pressure is provided by a ram [90 which fits the cylinder 19 and is moved downwardly to displace liquid, such as water, in the cylinder 19 between the ram 19a and the top of the support 22.
  • a ram 90 which fits the cylinder 19 and is moved downwardly to displace liquid, such as water, in the cylinder 19 between the ram 19a and the top of the support 22.
  • the hydrostatic pressures would ordinarily be more than 15 kbar.
  • FIG. 3 schematically shows a crucible 24 containing a metal melt 25 heated by an induction coil 26 which surrounds the crucible 24.
  • the coil 26 is wound from the multi-layer conductor of the present invention, such as the one illustrated by FIG. 2. Its terminal ends are connected with a suitable AC current supply 27 via connections 28 of the type providing for the introduction and removal of cooling water as indicated by the arrows shown in FIG. 3.
  • the crucible 24 and coil 26 are separable from each other so that a standard or copper or copper alloy tubular conductor coil may be used with the crucible if desired. It is to be understood that the crucible and coil may be standardized products of a furnace manufacturer, the difference between the coils being only that one may be in accord with the present invention and the other may be the standard prior art all-copper coil.
  • the furnace of FIG. 3 and furnaces of other designs having separable crucibles and coils may be standardized in construction, but providing for two alternative coils, one being the usual copper coil and the other being a coil according to the present invention, and the two kinds of coils may be given identical measurements so that they can be mounted in the furnace and connected to the electrical supply.
  • a coil made according to the present invention will first of all be considerably less expensive than the copper coil, but on the other hand the electrical losses will be somewhat higher.
  • a coil made according to the present invention using an aluminumcopper combination will involve losses about 25 percent higher than in the case of a conventional pure copper coil, but the manufacturing cost of the coil of this invention will be only about one-third that of the copper coil, this being based on the present cost of the two metals.
  • An electric induction furnace having a crucible for containing a metal melt and an electric induction coil for inductively heating a melt in said crucible, said coil being a coiled tubular conductor through which a cooling liquid can be flowed; wherein the improvement comprises said conductor having inner and outer metal layers, said inner layer being a metal selected from the class consisting of copper and copper alloy, and the outer layer being some other metal and which is sub stantially free from copper, said other metal being a metal selected from the class consisting of aluminum and aluminum alloy, said layers having integrated interfaces substantially free from electrical resistance.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Power Engineering (AREA)
  • General Induction Heating (AREA)
  • Windings For Motors And Generators (AREA)
  • Coils Of Transformers For General Uses (AREA)
  • Transformer Cooling (AREA)
  • Coils Or Transformers For Communication (AREA)
  • Crucibles And Fluidized-Bed Furnaces (AREA)
US470604A 1973-05-18 1974-05-16 Electric induction furnace Expired - Lifetime US3900695A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE7307026A SE372870B (enrdf_load_stackoverflow) 1973-05-18 1973-05-18

Publications (1)

Publication Number Publication Date
US3900695A true US3900695A (en) 1975-08-19

Family

ID=20317512

Family Applications (1)

Application Number Title Priority Date Filing Date
US470604A Expired - Lifetime US3900695A (en) 1973-05-18 1974-05-16 Electric induction furnace

Country Status (7)

Country Link
US (1) US3900695A (enrdf_load_stackoverflow)
JP (1) JPS5020252A (enrdf_load_stackoverflow)
AT (1) AT328759B (enrdf_load_stackoverflow)
DE (1) DE2421671A1 (enrdf_load_stackoverflow)
FR (1) FR2230046B3 (enrdf_load_stackoverflow)
IT (1) IT1011763B (enrdf_load_stackoverflow)
SE (1) SE372870B (enrdf_load_stackoverflow)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4207451A (en) * 1978-03-13 1980-06-10 Thermatool Corporation Multi-layered electrical induction coil subjected to large forces
US4486641A (en) * 1981-12-21 1984-12-04 Ruffini Robert S Inductor, coating and method
US5418811A (en) * 1992-04-08 1995-05-23 Fluxtrol Manufacturing, Inc. High performance induction melting coil
US6192969B1 (en) 1999-03-22 2001-02-27 Asarco Incorporated Casting of high purity oxygen free copper
US6428858B1 (en) 2001-01-25 2002-08-06 Jimmie Brooks Bolton Wire for thermal spraying system
US20020192134A1 (en) * 2001-05-25 2002-12-19 Japan Nuclear Cycle Development Institute Pyrochemical reprocessing method for spent nuclear fuel and induction heating system to be used in pyrochemical reprocessing method
US20110290364A1 (en) * 2010-03-31 2011-12-01 Halcor Metal Works S.A. Seamless composite metal tube and method of manufacturing the same
US20140353002A1 (en) * 2013-05-28 2014-12-04 Nexans Electrically conductive wire and method of its production

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5525495Y2 (enrdf_load_stackoverflow) * 1974-09-28 1980-06-19
FR2566890B1 (fr) * 1984-06-29 1986-11-14 Commissariat Energie Atomique Cage froide pour creuset a fusion par induction electromagnetique a frequence elevee
DE3427034C2 (de) * 1984-07-21 1996-06-27 Km Europa Metal Ag Verwendung eines durch Bor bzw. Lithium desoxidierten sauerstofffreien Kupfers für Hohlprofile
DE102007054418A1 (de) * 2007-11-13 2009-05-14 Wolf Neumann-Henneberg Elektrischer Leiter und Stanzgitter mit Stegleitern aus einem solchen elektrischen Leiter
JP5455690B2 (ja) * 2010-02-04 2014-03-26 Ｃｋｄ株式会社 電磁コイル、電子レンズ、および電磁バルブ
KR102038356B1 (ko) 2016-02-18 2019-10-31 가부시키가이샤 덴소 헤드업 디스플레이 장치
JP6771142B2 (ja) 2016-04-28 2020-10-21 パナソニックＩｐマネジメント株式会社 ヘッドアップディスプレイ装置
JP6722902B2 (ja) 2016-05-31 2020-07-15 パナソニックＩｐマネジメント株式会社 ヘッドアップディスプレイ装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3017485A (en) * 1957-11-19 1962-01-16 Asea Ab Means for electric vacuum furnaces
US3414660A (en) * 1964-12-16 1968-12-03 Asea Ab Means for protection against and/or indication of faults in coreless induction furnaces, heating furnaces and the like
US3704336A (en) * 1971-04-01 1972-11-28 Ajax Magnethermic Corp Support means for induction coil

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3017485A (en) * 1957-11-19 1962-01-16 Asea Ab Means for electric vacuum furnaces
US3414660A (en) * 1964-12-16 1968-12-03 Asea Ab Means for protection against and/or indication of faults in coreless induction furnaces, heating furnaces and the like
US3704336A (en) * 1971-04-01 1972-11-28 Ajax Magnethermic Corp Support means for induction coil

Cited By (14)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4207451A (en) * 1978-03-13 1980-06-10 Thermatool Corporation Multi-layered electrical induction coil subjected to large forces
US4486641A (en) * 1981-12-21 1984-12-04 Ruffini Robert S Inductor, coating and method
US5418811A (en) * 1992-04-08 1995-05-23 Fluxtrol Manufacturing, Inc. High performance induction melting coil
US5588019A (en) * 1992-04-08 1996-12-24 Fluxtrol Manufacturing, Inc. High performance induction melting coil
US6192969B1 (en) 1999-03-22 2001-02-27 Asarco Incorporated Casting of high purity oxygen free copper
US6861612B2 (en) 2001-01-25 2005-03-01 Jimmie Brooks Bolton Methods for using a laser beam to apply wear-reducing material to tool joints
US6428858B1 (en) 2001-01-25 2002-08-06 Jimmie Brooks Bolton Wire for thermal spraying system
US20020192134A1 (en) * 2001-05-25 2002-12-19 Japan Nuclear Cycle Development Institute Pyrochemical reprocessing method for spent nuclear fuel and induction heating system to be used in pyrochemical reprocessing method
US6793894B2 (en) * 2001-05-25 2004-09-21 Japan Nuclear Cycle Development Institute Pyrochemical reprocessing method for spent nuclear fuel and induction heating system to be used in pyrochemical reprocessing method
US20070163386A1 (en) * 2001-05-25 2007-07-19 Japan Nuclear Cycle Development Institute Pyrochemical reprocessing method for spent nuclear fuel
US7323032B2 (en) 2001-05-25 2008-01-29 Japan Nuclear Cycle Development Institute Pyrochemical reprocessing method for spent nuclear fuel
US20110290364A1 (en) * 2010-03-31 2011-12-01 Halcor Metal Works S.A. Seamless composite metal tube and method of manufacturing the same
US8663813B2 (en) * 2010-03-31 2014-03-04 Halcor Metal Works S.A. Seamless composite metal tube and method of manufacturing the same
US20140353002A1 (en) * 2013-05-28 2014-12-04 Nexans Electrically conductive wire and method of its production

Also Published As

Publication number Publication date
FR2230046B3 (enrdf_load_stackoverflow) 1977-03-11
JPS5020252A (enrdf_load_stackoverflow) 1975-03-04
AT328759B (de) 1976-04-12
ATA405774A (de) 1975-06-15
IT1011763B (it) 1977-02-10
DE2421671A1 (de) 1974-12-05
FR2230046A1 (enrdf_load_stackoverflow) 1974-12-13
SE372870B (enrdf_load_stackoverflow) 1975-01-13

Similar Documents

Publication Publication Date Title
US3900695A (en) Electric induction furnace
US4079192A (en) Conductor for reducing leakage at high frequencies
KR860001382B1 (ko) 전봉관(電縫管)제조용 임피이더(impeder)
US3566008A (en) Mechanical and electrical joint between copper and aluminum members and method of making such joint
GB2282558A (en) Resistance welding electrode and metod of manufacturing same
US2727945A (en) High frequency magnetic elements and telecommunication circuits
US3355796A (en) Manufacture of clad rods, wires and the like
US3800061A (en) Composite conductor containing superconductive wires
US2908739A (en) Water cooled crucible for high frequency heating
CN111451497B (zh) 一种平行纤维强化银石墨带状触头材料及其制备方法
US3666869A (en) Method and apparatus for setting up a temperature gradient
WO1996000448A1 (en) Superconductor with high volume copper and a method of making the same
US4814235A (en) Use of oxygen-free copper deoxidized by boron or lithium as material for hollow sections
CN107598176A (zh) 一种银金属氧化物电接触材料的制备工艺
US2120561A (en) Composite metallic bodies
EP0613583A1 (en) METHOD FOR PRODUCING A MELT-FUSE.
US2792482A (en) Heating means for billet containers of metal extrusion presses
DE3567397D1 (en) Process for the multiple use of a copper wire as an electrode wire in electric-resistance longitudinal seam welding
US2892988A (en) Electrical resistance elements and method of producing the same
GB1372798A (en) Induction heating coils
JPH02101108A (ja) 誘導加熱装置およびそれを使用する取鍋精錬方法
CN114086020A (zh) 基于自发热氧化工艺的银氧化锡电接触材料的制备方法及其产品
SU803725A1 (ru) Заготовка дл изготовлени сверхпровод щего кабельного издели
CN1042273C (zh) 互感器导电杆及其制造方法
US1681950A (en) Multiple-path water-cooled furnace