NO127646B - - Google Patents
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- Publication number
- NO127646B NO127646B NO04711/70A NO471170A NO127646B NO 127646 B NO127646 B NO 127646B NO 04711/70 A NO04711/70 A NO 04711/70A NO 471170 A NO471170 A NO 471170A NO 127646 B NO127646 B NO 127646B
- Authority
- NO
- Norway
- Prior art keywords
- field
- melting
- arc
- furnace
- furnaces
- Prior art date
Links
- 238000002844 melting Methods 0.000 claims description 13
- 230000008018 melting Effects 0.000 claims description 11
- 229910052751 metal Inorganic materials 0.000 claims description 11
- 239000002184 metal Substances 0.000 claims description 11
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 5
- 238000010891 electric arc Methods 0.000 claims description 5
- 239000010936 titanium Substances 0.000 claims description 5
- 229910052719 titanium Inorganic materials 0.000 claims description 5
- 230000015572 biosynthetic process Effects 0.000 claims description 4
- 230000000694 effects Effects 0.000 claims description 4
- 238000000034 method Methods 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 229910045601 alloy Inorganic materials 0.000 claims description 3
- 239000000956 alloy Substances 0.000 claims description 3
- 229910052845 zircon Inorganic materials 0.000 claims description 3
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 claims description 3
- 150000002739 metals Chemical class 0.000 claims description 2
- -1 titanium and zircon Chemical class 0.000 claims description 2
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 239000010949 copper Substances 0.000 description 2
- 238000003723 Smelting Methods 0.000 description 1
- 238000013019 agitation Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005669 field effect Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000009257 reactivity Effects 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Classifications
-
- 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
- H05B7/00—Heating by electric discharge
- H05B7/02—Details
- H05B7/14—Arrangements or methods for connecting successive electrode sections
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S403/00—Joints and connections
- Y10S403/05—Carbon electrode
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Plasma & Fusion (AREA)
- Discharge Heating (AREA)
- Furnace Details (AREA)
- Manufacture And Refinement Of Metals (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
- Coke Industry (AREA)
Description
Fremgangsmåte ved drift av elektriske lysbueovner. Procedure for operating electric arc furnaces.
Oppfinnelsen angår driften av elektriske lysbueovner og er særlig, men ikke helt og holdent, rettet mot lysbuesmelteov-ner som anvender forbrukbare elektroder av et sterkt reaktivt metall, f. eks. titan, og hvor smeltningen finner sted under vakuum. The invention relates to the operation of electric arc furnaces and is particularly, but not entirely, aimed at arc melting furnaces that use consumable electrodes of a highly reactive metal, e.g. titanium, and where the melting takes place under vacuum.
I det øyemed å oppnå kontroll av lysbuen er det vanlig ved ovner av denne type å anbringe et magnetisk felt i aksiell ret ning i forhold til ovnen i den hensikt å hindre dannelsen av lysbuer mellom elektroden og ovnens kobbervegger. For tiden fremstilles det magnetiske felt ved hjelp av spoler som innhyller ovnen og fører li-kestrøm. In order to achieve control of the arc, it is common for furnaces of this type to place a magnetic field in the axial direction in relation to the furnace in order to prevent the formation of arcs between the electrode and the copper walls of the furnace. Currently, the magnetic field is produced using coils that surround the oven and carry direct current.
Selv når en tar ovennevnte forholds-regler oppstår der situasjoner hvor kontroll av buen midlertidig tapes, og for å sik-re en mer pålitelig buekontroll er det ønske-lig å anvende sterkere eller mer intense magnetfelter. Ved økning av magnetfeltets styrke til en verdi passende for lysbuesta-bilisering er det imidlertid funnet at om-røringen av den smeltede metalldam, noe som normalt er fordelaktig, øker over en kontrollerbar grense idet der dannes en strømhvirvel av metall som har tendens til å trenge inn i rommet mellom elek-trodens sider og ovnens vegger. Videre for-årsaker den overdrevne omrøring et uøn-sket varmetap fra metalldammen. Even when the above precautions are taken, situations arise where control of the arc is temporarily lost, and to ensure a more reliable arc control it is desirable to use stronger or more intense magnetic fields. However, on increasing the strength of the magnetic field to a value suitable for arc stabilization, it has been found that the agitation of the molten metal pool, which is normally beneficial, increases beyond a controllable limit as a current vortex of metal is formed which tends to penetrate into the space between the sides of the electric trode and the walls of the oven. Furthermore, the excessive stirring causes an unwanted heat loss from the metal pond.
Ifølge foreliggende oppfinnelse omfat-ter en fremgangsmåte for drift av elektriske lysbueovner, særlig lysbuesmelteov-ner som arbeider i vakuum og er bestemt til smeltning av høytsmeltende, sterkt re-aktive metaller som titan og zirkon, og hvor det anvendes en forbrukbar elektrode av det metall eller den legering som skal smeltes, omfattende tilføring til det indre av ovnen av et magnetisk felt med aksial retning i forhold til ovnen og av tilstrekkelig styrke til å stabilisere buen, og oppfinnelsen karakteriseres ved at feltets retning reverseres med tilstrekkelig frekvens til å redusere feltets omrørende virkning og å hindre hvirveldannelse i metalldammen. According to the present invention, a method for operating electric arc furnaces, in particular arc melting furnaces which work in vacuum and are intended for melting high-melting, highly reactive metals such as titanium and zircon, and where a consumable electrode of that metal is used or the alloy to be melted, comprising supplying to the interior of the furnace a magnetic field with an axial direction relative to the furnace and of sufficient strength to stabilize the arc, and the invention is characterized by the fact that the direction of the field is reversed with sufficient frequency to reduce the stirring of the field effect and to prevent vortex formation in the metal pond.
Fortrinnsvis anvendes oppfinnelsen ved smeltning av ildfaste metaller eller lege-ringer med høy kjemisk reaksjonsevne, f. eks. titan, eller zirkon, idet en anvender forbrukbare elektroder og idet smeltningen utføres i vakkum, d.v.s. under slike trykk-forhold at lysbuen har en diffus karakter. Trykk på ca. i/2 mm eller mindre er spesi-elt egnet for dette formål. The invention is preferably used when melting refractory metals or alloys with high chemical reactivity, e.g. titanium, or zircon, as consumable electrodes are used and as the melting is carried out in a vacuum, i.e. under such pressure conditions that the arc has a diffuse character. Press approx. 1/2 mm or less is particularly suitable for this purpose.
Ifølge foreliggende oppfinnelse er det av viktighet at tidssyklusen til det magnetiske felt, d.v.s. avstanden langs tidsak-sen mellom korresponderende punkter på felt/tidsdiagrammet, varierer fra omkring 0,1 sek til omkring 5 sek, fortrinnsvis 0,1 til 2 sek., og for dette formål anvendes likestrøm som reverseres med passende frekvens. Det skal forstås at frekvensen av strømreverseringen i spolene ikke må være så høy at der dannes hvirvelstrømmer i ovnens kobbervegger. Når en f. eks. anvender alternerende strømmer med en frekvens av 50 cykler pr. sek., er det funnet at på grunn av dannelsen av hvirvelstrøm-mer faller det magnetiske felt i det indre av ovnen i en vesentlig grad og kan til og med reduseres til null. According to the present invention, it is important that the time cycle of the magnetic field, i.e. the distance along the time axis between corresponding points on the field/time diagram varies from about 0.1 sec to about 5 sec, preferably 0.1 to 2 sec., and for this purpose direct current is used which is reversed with a suitable frequency. It should be understood that the frequency of current reversal in the coils must not be so high that eddy currents are formed in the copper walls of the furnace. When an e.g. uses alternating currents with a frequency of 50 cycles per sec., it has been found that due to the formation of eddy currents, the magnetic field in the interior of the furnace falls to a significant extent and can even be reduced to zero.
Ved anvendelsen av et magnetisk felt som reverseres med en passende frekvens, er det funnet mulig å øke feltets styrke, da feltets omrøringsvirkning i en retning er motvirket når feltet reverseres slik at det under ingen deler av cyklusen kan dannes vesentlige hvirvler i metalldammen, og videre reduseres varmetapene. I stedenfor oppnåes en svak turbulens som tilveiebrin-ger en blanding av smeiten. Således mens titansmelteovner tidligere har vært drevet med en strøm i feltspolene av 2 amp. og et gitt antall vinninger, kan strømstyrker opp til 10 amp. nå anvendes idet feltets tidscyklus er 0,75 sek. for en strømstyrke av 10 amp. By using a magnetic field which is reversed with a suitable frequency, it has been found possible to increase the strength of the field, as the stirring effect of the field in one direction is counteracted when the field is reversed so that during no part of the cycle can significant vortices be formed in the metal pond, and further heat losses are reduced. Instead, a weak turbulence is achieved which provides a mixture of the melt. Thus, while titanium melting furnaces have previously been operated with a current in the field coils of 2 amp. and a given number of turns, currents can be up to 10 amp. is now used as the field's time cycle is 0.75 sec. for a current of 10 amp.
Da magnetfeltets styrke således kan økes, kan en oppnå større kontroll av den elektriske lysbue og mange uønskete side-virkninger ved lysbuen er redusert eller eli-minert. I denne forbindelse skal der nev-nes en uønsket effekt som en har merket ved industrielle smelteoperasjoner, hvor en på grunn av egenskapene til atmosfæren inne i ovnen og de magnetiske tilstander som der hersker, oppnår en glimutladning mellom elektroden og ovnens vegger. Til-stedeværelsen av denne glimutladning er meget alvorlig, da en stor andel av den til-førte strøm til ovnen vil forbigå buen og gå gjennom glimutladningen. As the strength of the magnetic field can thus be increased, greater control of the electric arc can be achieved and many unwanted side effects of the arc are reduced or eliminated. In this connection, mention should be made of an unwanted effect that has been noticed in industrial smelting operations, where due to the characteristics of the atmosphere inside the furnace and the magnetic conditions that prevail there, a glow discharge is obtained between the electrode and the walls of the furnace. The presence of this glow discharge is very serious, as a large proportion of the current supplied to the furnace will bypass the arc and go through the glow discharge.
Ved alvorligere tilfeller kan dette re-sultere i en reduksjon av smeltehastighe- In more severe cases, this can result in a reduction in melting speed
ten til omtrent null, og som videre er øde-leggende for strukturen av den støpte barre. Ved å drive smelteovnen ifølge foreliggende oppfinnelse, er imidlertid tenden-sen til glimutladning vesentlig redusert. ten to approximately zero, and which is further devastating for the structure of the cast ingot. By operating the melting furnace according to the present invention, however, the tendency to flash discharge is substantially reduced.
En videre fordel ved oppfinnelsen er at den resulterer i barrer med meget rene overflater. A further advantage of the invention is that it results in ingots with very clean surfaces.
Claims (2)
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19702001212 DE2001212B2 (en) | 1970-01-13 | 1970-01-13 | SCREW NIPPLE CONNECTION OF COAL OR GRAPHITE ELECTRODES IN ELECTRIC OVENS |
Publications (2)
Publication Number | Publication Date |
---|---|
NO127647B NO127647B (en) | 1973-07-23 |
NO127646B true NO127646B (en) | 1973-07-23 |
Family
ID=5759481
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
NO04711/70A NO127646B (en) | 1970-01-13 | 1970-12-08 |
Country Status (15)
Country | Link |
---|---|
US (1) | US3727095A (en) |
JP (1) | JPS4811542B1 (en) |
AT (1) | AT298088B (en) |
BE (1) | BE760964A (en) |
CA (1) | CA935853A (en) |
CH (1) | CH543214A (en) |
DE (1) | DE2001212B2 (en) |
ES (1) | ES194627Y (en) |
FR (1) | FR2074536A1 (en) |
GB (1) | GB1275894A (en) |
LU (1) | LU62394A1 (en) |
NO (1) | NO127646B (en) |
SE (1) | SE357870B (en) |
YU (1) | YU34168B (en) |
ZA (1) | ZA71210B (en) |
Families Citing this family (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE2226230C3 (en) * | 1972-05-30 | 1984-07-12 | Sigri Elektrographit Gmbh, 8901 Meitingen | Prefabricated part of a graphite electrode |
JPS5260937U (en) * | 1975-10-30 | 1977-05-04 | ||
US4005326A (en) * | 1975-10-31 | 1977-01-25 | Shigeru Suga | Electrode mounting in an arc lamp for use in light fastness testers |
US4006380A (en) * | 1975-10-31 | 1977-02-01 | Shigeru Suga | Mounting of carbon electrodes on a holder of an arc lamp |
US5575582A (en) * | 1995-01-18 | 1996-11-19 | Ucar Carbon Technology Corporation | Fastening device for securing electrode joints |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US1572534A (en) * | 1923-10-27 | 1926-02-09 | Nat Carbon Co Inc | Sectional electrode with locked screw-thread joint |
NL101950C (en) * | 1958-07-25 | 1900-01-01 | ||
US2969251A (en) * | 1960-02-15 | 1961-01-24 | Great Lakes Carbon Corp | Carbon electrode joint |
-
1970
- 1970-01-13 DE DE19702001212 patent/DE2001212B2/en active Pending
- 1970-11-03 CH CH1627970A patent/CH543214A/en not_active IP Right Cessation
- 1970-11-09 SE SE15110/70A patent/SE357870B/xx unknown
- 1970-11-17 GB GB54633/70A patent/GB1275894A/en not_active Expired
- 1970-11-26 ES ES1970194627U patent/ES194627Y/en not_active Expired
- 1970-12-02 YU YU2929/70A patent/YU34168B/en unknown
- 1970-12-08 NO NO04711/70A patent/NO127646B/no unknown
- 1970-12-16 AT AT1130270A patent/AT298088B/en active
- 1970-12-22 FR FR7047629A patent/FR2074536A1/fr not_active Withdrawn
- 1970-12-22 JP JP45115246A patent/JPS4811542B1/ja active Pending
- 1970-12-29 BE BE760964A patent/BE760964A/en unknown
-
1971
- 1971-01-08 US US00104907A patent/US3727095A/en not_active Expired - Lifetime
- 1971-01-11 LU LU62394D patent/LU62394A1/xx unknown
- 1971-01-13 CA CA102639A patent/CA935853A/en not_active Expired
- 1971-01-13 ZA ZA710210A patent/ZA71210B/en unknown
Also Published As
Publication number | Publication date |
---|---|
GB1275894A (en) | 1972-05-24 |
ES194627U (en) | 1975-01-01 |
LU62394A1 (en) | 1971-08-02 |
CA935853A (en) | 1973-10-23 |
NO127647B (en) | 1973-07-23 |
YU292970A (en) | 1978-05-15 |
ES194627Y (en) | 1975-05-01 |
US3727095A (en) | 1973-04-10 |
DE2001212A1 (en) | 1971-07-29 |
BE760964A (en) | 1971-05-27 |
YU34168B (en) | 1978-12-31 |
ZA71210B (en) | 1971-10-27 |
DE2001212B2 (en) | 1972-01-20 |
FR2074536A1 (en) | 1971-10-01 |
JPS4811542B1 (en) | 1973-04-13 |
AT298088B (en) | 1972-04-25 |
CH543214A (en) | 1973-10-15 |
SE357870B (en) | 1973-07-09 |
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