JP2001021270A - Three-phase ac arc electric furnace - Google Patents
Three-phase ac arc electric furnaceInfo
- Publication number
- JP2001021270A JP2001021270A JP11197170A JP19717099A JP2001021270A JP 2001021270 A JP2001021270 A JP 2001021270A JP 11197170 A JP11197170 A JP 11197170A JP 19717099 A JP19717099 A JP 19717099A JP 2001021270 A JP2001021270 A JP 2001021270A
- Authority
- JP
- Japan
- Prior art keywords
- electric furnace
- phase
- furnace
- conductor
- electric
- 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.)
- Pending
Links
Classifications
-
- 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
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、炉用変圧器と、
それに接続された二次側導体と、それに接続された電極
とからなり、被溶解物を三相交流のアーク放電で溶解す
る電気炉に関する。[0001] The present invention relates to a furnace transformer,
The present invention relates to an electric furnace including a secondary conductor connected thereto and an electrode connected thereto, and melting an object to be melted by three-phase alternating current arc discharge.
【０００２】[0002]
【従来の技術】従来技術を図５、図６、図７を用いて説
明する。図５は従来技術に係る電気炉全体の配置図であ
る。図６および図７は従来技術に係る電気炉における電
気設備の単線結線図である。図５に示すように、従来技
術においては炉用変圧器１の二次側端子から電気室壁端
子２までを固定の導体３とし、電気室壁４から電気炉本
体上部の固定導体５までを可とう性のある導体６として
いた。なお、この可とう性のある導体６は電気炉の電極
を昇降させる為に可とう性をもたせる必要があった。こ
こで、図５に示す電気設備のインピーダンス（以下、電
気炉インピーダンスという。）は、炉用変圧器１、各固
定導体３、可とう性導体６および電気炉上部の固定導体
５の配置で決定され、この値は固定であった。そこで、
電気炉の操業状況に応じて電気炉インピーダンスを変更
する必要がある場合には、炉用変圧１の一次側にタップ
切替え器付きのリアクトル７を接続し、そのタップを切
替えることで電気炉インピーダンスを変更していた。2. Description of the Related Art A conventional technique will be described with reference to FIGS. FIG. 5 is a layout view of the entire electric furnace according to the related art. 6 and 7 are single-line diagrams of electric equipment in an electric furnace according to the related art. As shown in FIG. 5, in the related art, the conductor from the secondary terminal of the furnace transformer 1 to the electric chamber wall terminal 2 is a fixed conductor 3, and the conductor from the electric chamber wall 4 to the fixed conductor 5 in the upper part of the electric furnace main body. The flexible conductor 6 was used. The flexible conductor 6 had to be flexible in order to raise and lower the electrodes of the electric furnace. Here, the impedance of the electric equipment shown in FIG. 5 (hereinafter referred to as electric furnace impedance) is determined by the arrangement of the furnace transformer 1, each fixed conductor 3, the flexible conductor 6, and the fixed conductor 5 on the upper part of the electric furnace. And this value was fixed. Therefore,
If it is necessary to change the electric furnace impedance in accordance with the operating conditions of the electric furnace, connect a reactor 7 with a tap changer to the primary side of the furnace transformer 1 and switch the tap to reduce the electric furnace impedance. Had changed.
【０００３】なお、リアクトルに付属のタップ切替え器
には、通常「負荷時タップ切替え器」あるいは「無電圧
タップ切替え器」が用いられる。タップを切替える場合
に、例えば、タップ切替え器が「負荷時タップ切替え
器」の場合は、電気炉に電流をしながらタップを切替え
ることができる。一方、タップ切替え器が「無電圧タッ
プ切替え器」の場合には、図６に示すような構成の場
合、電気炉への電流を遮断器８により遮断してからタッ
プを切替える必要があり、切替え中は電気炉を停止する
ことが必要となる。ただし「無電圧タップ切替え器」の
場合でも、図７に示すような回路構成にすることによ
り、電気炉の停止を回避することは一応可能である。[0003] As a tap changer attached to the reactor, a "load tap changer" or a "no-voltage tap changer" is usually used. When the tap is switched, for example, when the tap switch is a “load tap switch”, the tap can be switched while applying current to the electric furnace. On the other hand, when the tap changer is a “no-voltage tap changer”, in the case of the configuration shown in FIG. 6, it is necessary to cut off the current to the electric furnace by the circuit breaker 8 and then change the tap. During this time, it is necessary to shut down the electric furnace. However, even in the case of the "no-voltage tap changer", it is possible to avoid stopping the electric furnace by adopting a circuit configuration as shown in FIG.
【０００４】[0004]
【発明が解決しようとする課題】上述した従来技術にお
いては、リアクトル７を炉用変圧器１の一次側に設置す
ることで電気炉インピーダンスの変更を行うが、この場
合電気室にリアクトル７を設置するためのスペースが必
要になり、さらにリアクトル７の設置に係る費用が必要
になる。また、タップ切替え器を切替えに時間のかから
ない「負荷時タップ切替え器」にするとリアクトルが大
型となる。一方、「無電圧タップ切替え器」の場合、図
７のような構成にすることにより操業の中断を回避でき
るが、図６の場合と比較して遮断器９，１０の2台分の
設置スペースと費用が余分に掛かることとなる。しか
も、いずれもタップの切替によるために、設定値は断続
的となり、操業状況に応じたきめ細かな電気炉インピー
ダンスの調整ができない。In the above-mentioned prior art, the electric furnace impedance is changed by installing the reactor 7 on the primary side of the furnace transformer 1. In this case, the reactor 7 is installed in the electric room. In addition, a space for performing the operation is required, and further, a cost for installing the reactor 7 is required. In addition, if the tap changer is a “load-time tap changer” that does not require much time for switching, the reactor becomes large. On the other hand, in the case of the “no-voltage tap changer”, the operation interruption can be avoided by adopting the configuration as shown in FIG. 7, but the installation space for the two circuit breakers 9 and 10 is smaller than that of FIG. And extra costs. In addition, the setting value is intermittent because all of the taps are switched, and it is not possible to finely adjust the electric furnace impedance in accordance with the operating condition.
【０００５】この発明は、以上の問題点を解決し、省ス
ペース化が可能で、かつ低コストで電気炉インピーダン
スの無段階連続的な制御が可能な三相交流アーク式電気
炉を提供することを目的とする。An object of the present invention is to provide a three-phase AC arc type electric furnace capable of solving the above problems, saving space, and controlling the electric furnace impedance steplessly and continuously at low cost. With the goal.
【０００６】[0006]
【課題を解決するための手段】上記の課題は次の発明に
より解決される。請求項１に記載の発明は、炉用変圧器
と、それに接続された二次側導体と、それに接続された
電極とからなり、被溶解物を三相交流のアーク放電で溶
解する電気炉において、前記二次側導体の各相間距離の
変更手段を有することを特徴とする三相交流アーク式電
気炉である。The above object is achieved by the following invention. The invention according to claim 1 is an electric furnace that includes a transformer for a furnace, a secondary conductor connected to the furnace, and an electrode connected to the furnace, and melts an object to be melted by three-phase alternating current arc discharge. And a means for changing the distance between the phases of the secondary-side conductor.
【０００７】この発明は、電気炉用変圧器の二次側導体
の各相間距離を変更できる構造とすることにより、電気
炉インピーダンスを通電中無段階に変更させることが可
能となる。これにより、電気炉の停止を伴うことなく、
かつ容易に電気炉の操業時期に応じた適切な電気炉イン
ピーダンスに変更することができる。According to the present invention, the electric furnace impedance can be changed steplessly during energization by employing a structure in which the distance between the phases of the secondary conductor of the electric furnace transformer can be changed. As a result, without stopping the electric furnace,
In addition, it is possible to easily change the electric furnace impedance to an appropriate electric furnace impedance according to the operation time of the electric furnace.
【０００８】請求項２に記載の発明は、二次側導体の各
相間距離の変更手段は、二次側導体の中間部に設けられ
た端子と、該端子の前後に接続された可とう性のある導
体と、前記端子の移動手段であることを特徴とする請求
項１に記載の三相交流アーク式電気炉である。According to a second aspect of the present invention, the means for changing the distance between the phases of the secondary conductor includes a terminal provided at an intermediate portion of the secondary conductor, and a flexible member connected before and after the terminal. The three-phase AC arc type electric furnace according to claim 1, wherein the three-phase AC arc type electric furnace is a conductor having a hole and a moving means of the terminal.
【０００９】この発明は、電気室壁の貫通部に設置され
ている三相個別の壁端子の距離を任意に変更できる構造
とすることにより、電気炉用変圧器の二次側導体の各層
間距離を調整する。これにより、電気炉の停止を伴うこ
となく、かつ容易に電気炉の操業時期に応じた適切な電
気炉インピーダンスに変更することができる。The present invention provides a structure in which the distance between the three-phase individual wall terminals installed in the penetrating portion of the wall of the electric room can be arbitrarily changed, so that each layer of the secondary conductor of the electric furnace transformer can be formed. Adjust the distance. Thus, the electric furnace impedance can be easily changed to an appropriate electric furnace impedance according to the operation time of the electric furnace without stopping the electric furnace.
【００１０】[0010]
【発明の実施の形態】本発明の実施の形態を図を用いて
説明する。DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described with reference to the drawings.
【００１１】炉用変圧器１の二次側導体の相間距離を変
えることにより、電気炉インピーダンスの変更を行う場
合の原理を図４に示す。ここで、図４は炉用変圧器１か
ら電気炉本体までを三線結線図で示したものである。各
相の導体のインピーダンスはそれぞれの導体の形状、大
きさで決定される自己インダクタンスL1,L2,L3と各導体
間の距離によって決定される相互インダクタンスM12, M
23, M31によって決定される。三相交流の場合には各導
体のインピーダンスZ1,Z2,Z3は、以下の式であらわされ
る。FIG. 4 shows the principle of changing the electric furnace impedance by changing the phase distance between the secondary conductors of the furnace transformer 1. Here, FIG. 4 shows a three-line connection diagram from the furnace transformer 1 to the electric furnace main body. The impedance of the conductor in each phase is determined by the shape and size of each conductor, and the mutual inductance M12, M is determined by the distance between the conductors, L1, L2, and L3.
23, determined by M31. In the case of three-phase alternating current, the impedances Z1, Z2, Z3 of each conductor are represented by the following equations.
【００１２】 Z1＝ω×L1+a×ω×M12+a2×ω×M31 Z2＝ω×L2+a×ω×M23+a2×ω×M12 Z3＝ω×L3+a×ω×M31+a2×ω×M23 ここで、 ω：角周波数 a：-1/2 + j√3/2 a2：-1/2 - j√3/2 である。Z1 = ω × L1 + a × ω × M12 + a 2 × ω × M31 Z2 = ω × L2 + a × ω × M23 + a 2 × ω × M12 Z3 = ω × L3 + a × ω × M31 + a 2 × ω × M23 where ω: angular frequency a: -1/2 + j√3 / 2 a 2 : -1/2-j√3 / 2.
【００１３】相互インダクタンスM12, M23, M31は導体
の相互の距離が大きくなるほど小さくなり、距離が小さ
くなるほど大きくなるので、この導体距離を可変にする
ことで各相のインピーダンスを可変とすることができ
る。The mutual inductances M12, M23, and M31 decrease as the distance between the conductors increases, and increase as the distance decreases. Therefore, by varying the conductor distance, the impedance of each phase can be varied. .
【００１４】本発明に係る実施の形態を図１、図２、図
３に示す。ここで、図１は電気室壁の断面方向から見た
電気炉全体の配置図、図２は電気室壁の端子部の正面
図、図３は電気室壁の端子距離を可変する部分の詳細図
である。図１に示すように各相毎に炉用変圧器１の二次
側端子に接続された可とう導体１１は電気室壁４の貫通
部に設置されている壁端子１２に接続される。壁端子１
２の電気室外側に接続された可とう導体６は電気炉本体
の上部導体５に接続される。なお、可とう導体１１およ
び可とう導体６は通過する電流量によって複数の導体に
より構成しても良い。An embodiment according to the present invention is shown in FIGS. 1, 2 and 3. FIG. Here, FIG. 1 is a layout view of the entire electric furnace viewed from a cross-sectional direction of the electric room wall, FIG. 2 is a front view of a terminal portion of the electric room wall, and FIG. FIG. As shown in FIG. 1, a flexible conductor 11 connected to the secondary terminal of the furnace transformer 1 for each phase is connected to a wall terminal 12 provided in a penetrating portion of the electric chamber wall 4. Wall terminal 1
The flexible conductor 6 connected to the outside of the electric room 2 is connected to the upper conductor 5 of the electric furnace main body. Note that the flexible conductor 11 and the flexible conductor 6 may be formed of a plurality of conductors depending on the amount of current passing therethrough.
【００１５】図２に示すように壁端子１２は三相（R,S,
T）個別にあり、それぞれ電気室の壁に稼動できる範囲
で穴が空けられている。左右の相（R,S）は水平方向に
移動可能であり、また中相（T）は垂直方向に移動でき
るように穴が空けられている。なお、図２では壁端子１
２は1相当たりの板状の導体が2枚構成になっているが、
電流量によってこの数を変更できることはいうまでもな
い。As shown in FIG. 2, the wall terminal 12 has three phases (R, S,
T) Individually, each hole is drilled to the extent that it can be operated on the wall of the electrical room. The left and right phases (R, S) are movable in the horizontal direction, and the middle phase (T) is perforated so as to be movable in the vertical direction. Note that in FIG.
2 is composed of two plate-shaped conductors per phase,
It goes without saying that this number can be changed depending on the amount of current.
【００１６】図３に示すように壁端子１２は、絶縁物１
３によって覆われ壁から電気的に絶縁されている。その
絶縁物１３には車輪１４が設けられている。また、壁端
子１２の駆動用に壁穴に絶縁物１５を介して固定されて
いる駆動シリンダ１６が絶縁物１３に固定されている。
また、壁穴には絶縁物１７が敷かれその上にレール１８
が固定されている。As shown in FIG. 3, the wall terminal 12 is
3 and is electrically insulated from the wall. Wheels 14 are provided on the insulator 13. Further, a drive cylinder 16 fixed to the wall hole via an insulator 15 for driving the wall terminal 12 is fixed to the insulator 13.
An insulator 17 is laid in the wall hole, and a rail 18
Has been fixed.
【００１７】駆動シリンダ１６が伸縮することによっ
て、レール１８上を車輪１４を介して壁端子１２が移動
し、端子の移動に伴って可とう導体１１および可とう導
体６が各相間の距離を変えるように動く。As the drive cylinder 16 expands and contracts, the wall terminals 12 move on the rails 18 via the wheels 14, and the flexible conductors 11 and 6 change the distance between the phases as the terminals move. Move like so.
【００１８】なお、各相間インピーダンスの不平衡化を
防止するためには、各相間の距離は同時並行して変更す
ることが好ましいが、操業状況に応じて意図的に不平衡
とする場合もある。In order to prevent the imbalance of the impedance between the phases, it is preferable to change the distance between the phases at the same time. However, the distance may be intentionally unbalanced depending on the operation situation. .
【００１９】ここで、電気炉内の被溶解物を溶解する初
期段階においてアーク放電を安定化させるため電気炉イ
ンピーダンスを増やしたいときは、左右（R,S）の壁端
子１２を広げる方向に、さらに中相（T）の壁端子１２
を上方向に動かすことによって実現する。また、電気炉
内の被溶解物の精錬段階において電流を増やすため電気
炉インピーダンスを小さくしたいときは、左右（R,S）
の壁端子１２を狭める側に動かし中相（T）の壁端子４
を下方向に動かすことによって実現する。ここで、壁端
子１２を停止させる点は連続的に任意の点を定めても良
いし、あらかじめ何個所か停止位置を決めておいて、電
気炉の操業状況に応じて各点に移動させても良い。Here, when it is desired to increase the electric furnace impedance in order to stabilize the arc discharge in the initial stage of melting the material to be melted in the electric furnace, the left and right (R, S) wall terminals 12 are expanded in the direction of spreading. Furthermore, the wall terminal 12 of the middle phase (T)
Is realized by moving. If you want to reduce the electric furnace impedance to increase the current in the refining stage of the melt in the electric furnace, use the left and right (R, S)
The wall terminal 12 of the middle phase (T)
Is realized by moving. Here, the point at which the wall terminal 12 is stopped may be set continuously at an arbitrary point, or may be determined in advance at some points and moved to each point according to the operation state of the electric furnace. Is also good.
【００２０】なお、端子間距離を９００ｍｍ動かすこと
により約４０％のインピーダンスの変更が可能となるこ
とが確かめられている。It has been confirmed that the impedance can be changed by about 40% by moving the distance between terminals by 900 mm.
【００２１】[0021]
【発明の効果】本発明は、電気炉用変圧器の二次側導体
の各相間距離を変更することにより、電気炉インピーダ
ンスを通電中連続的に変更することが可能となり、省ス
ペース化が可能で、安価に電気炉インピーダンスの制御
が可能な三相交流アーク式電気炉を提供する。According to the present invention, it is possible to continuously change the electric furnace impedance during energization by changing the distance between each phase of the secondary conductor of the electric furnace transformer, thereby saving space. And a three-phase AC arc type electric furnace capable of controlling the electric furnace impedance at low cost.
【図１】本発明に係る電気室壁の断面方向から見た電気
炉全体の配置図である。FIG. 1 is a layout view of an entire electric furnace viewed from a cross-sectional direction of an electric room wall according to the present invention.
【図２】本発明に係る電気室壁の端子部の正面図であ
る。FIG. 2 is a front view of a terminal portion of an electric room wall according to the present invention.
【図３】本発明に係る電気室壁の端子距離を可変する部
分の詳細図である。FIG. 3 is a detailed view of a portion of the electric room wall that varies the terminal distance according to the present invention.
【図４】本発明に係るインピーダンス変更の原理を示す
図である。FIG. 4 is a diagram showing the principle of impedance change according to the present invention.
【図５】従来技術に係る電気炉全体の配置図である。FIG. 5 is a layout view of the entire electric furnace according to the related art.
【図６】従来技術に係る電気設備の単線結線図である。FIG. 6 is a single-line diagram of electric equipment according to the related art.
【図７】従来技術に係る電気設備の単線結線図である。FIG. 7 is a single-line diagram of electric equipment according to the related art.
１ 炉用変圧器 ２ 壁端子 ３ 炉用変圧器の上部導体 ４ 電気室壁 ５ 固定導体 ６ 可とう導体 ７ リアクトル ８ 遮断器 ９ 遮断器 １０ 遮断器 １１ 可とう導体 １２ 壁端子 DESCRIPTION OF SYMBOLS 1 Furnace transformer 2 Wall terminal 3 Upper conductor of furnace transformer 4 Electric room wall 5 Fixed conductor 6 Flexible conductor 7 Reactor 8 Circuit breaker 9 Circuit breaker 10 Circuit breaker 11 Flexible conductor 12 Wall terminal
───────────────────────────────────────────────────── フロントページの続き (51)Int.Cl.7 識別記号 ＦＩ テーマコート゛(参考） Ｈ０５Ｂ 7/144 Ｈ０５Ｂ 7/144 Ｚ 7/18 7/18 Ａ Ｆターム(参考） 3K084 AA05 AA11 AA12 BC01 BC02 DA02 DA11 4K045 AA04 BA02 DA02 GB03 4K063 AA03 AA04 AA12 BA02 BA13 CA01 CA04 CA06 FA53 FA74 FA78 ──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. 7 Identification symbol FI Theme coat ゛ (Reference) H05B 7/144 H05B 7/144 Z 7/18 7/18 A F term (Reference) 3K084 AA05 AA11 AA12 BC01 BC02 DA02 DA11 4K045 AA04 BA02 DA02 GB03 4K063 AA03 AA04 AA12 BA02 BA13 CA01 CA04 CA06 FA53 FA74 FA78
Claims (2)
導体と、それに接続された電極とからなり、被溶解物を
三相交流のアーク放電で溶解する電気炉において、前記
二次側導体の各相間距離の変更手段を有することを特徴
とする三相交流アーク式電気炉。1. An electric furnace, comprising a furnace transformer, a secondary conductor connected thereto, and an electrode connected thereto, wherein the electric furnace melts an object to be melted by a three-phase alternating current arc discharge. A three-phase AC arc type electric furnace having a means for changing a distance between phases of side conductors.
間部に設けられた端子と、該端子の前後に接続された可
とう性のある導体と、前記端子の移動手段であることを
特徴とする請求項１に記載の三相交流アーク式電気炉。2. The distance changing means is a terminal provided at an intermediate portion of a secondary side conductor, a flexible conductor connected before and after the terminal, and a means for moving the terminal. The three-phase AC arc type electric furnace according to claim 1, wherein:
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11197170A JP2001021270A (en) | 1999-07-12 | 1999-07-12 | Three-phase ac arc electric furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP11197170A JP2001021270A (en) | 1999-07-12 | 1999-07-12 | Three-phase ac arc electric furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001021270A true JP2001021270A (en) | 2001-01-26 |
Family
ID=16369967
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP11197170A Pending JP2001021270A (en) | 1999-07-12 | 1999-07-12 | Three-phase ac arc electric furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001021270A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009125645A1 (en) | 2008-04-09 | 2009-10-15 | 新日本製鐵株式会社 | Induction heating apparatus and induction heating method |
-
1999
- 1999-07-12 JP JP11197170A patent/JP2001021270A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2009125645A1 (en) | 2008-04-09 | 2009-10-15 | 新日本製鐵株式会社 | Induction heating apparatus and induction heating method |
| US8420990B2 (en) | 2008-04-09 | 2013-04-16 | Nippon Steel & Sumitomo Metal Corporation | Induction heating apparatus and induction heating method |
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