JPH04262842A - Method for measuring molten metal level in mold for continuous casting - Google Patents

Abstract

PURPOSE:To accurately detect molten metal level in a mold for continuous casting regardless of the mold size and whether the width changes or not. CONSTITUTION:A transmitting coil 10 and a receiving coil 11 are burried as inserting the suitable level L of molten metal 2 in the mold 1, and the transmitting coil 10 is excited with low frequency exciting current outputted by oscillating circuit 12. Induction current induced to the receiving coil 11 with energy in magnetic field generated at this time, is grasped and phase difference between this and the above exciting current, is detected with a phase difference detector 14. The energy in the magnetic field reaching to the receiving coil 11 is influenced with length of propagation in the molten metal 2, i.e., height of the molten metal level, and phase lag and lowering of intensity are developed to induction current induced in the receiving coil 11. By using the phase difference outputted from the phase difference detector 14, the preset level of molten metal 2 is calculated with an arithmetic part 15.

Description

【発明の詳細な説明】[Detailed description of the invention]

【０００１】0001

【産業上の利用分野】本発明は、連続鋳造用の鋳型内部
に注入されて該鋳型の内部に滞留する溶湯のレベルを測
定する方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for measuring the level of molten metal injected into a mold for continuous casting and remaining inside the mold.

【０００２】0002

【従来の技術】連続鋳造設備の操業は、上下に開口を有
する筒形の鋳型に溶融金属（溶湯）を注入し、該鋳型の
水冷された内壁に接触せしめて冷却し、外側を凝固シェ
ルにて被覆された鋳片を得て、これを鋳型の下側開口部
から連続的に引き抜きつつ更に冷却し、内側にまで凝固
が進行した後に所定の寸法に切断して、圧延等の後工程
での素材となる製品鋳片を得る手順にて行われる。[Prior Art] The operation of continuous casting equipment involves pouring molten metal into a cylindrical mold with openings at the top and bottom, cooling it by contacting the water-cooled inner wall of the mold, and turning the outside into a solidified shell. The coated slab is obtained, and it is further cooled while being continuously pulled out from the lower opening of the mold, and after solidification progresses to the inside, it is cut into a predetermined size and used in subsequent processes such as rolling. This process is used to obtain product slabs, which are the raw material for the process.

【０００３】ところで連続鋳造設備においては、鋳型内
部の溶湯レベルを測定し、この測定結果と予め設定され
た適正レベルとの偏差を解消すべく溶湯の注入量を調節
するレベル制御が実施されており、このレベル制御は、
鋳型内部における溶湯の冷却状態を適正化し、製品鋳片
における表面疵の生成、ブレークアウトの発生等、連続
鋳造設備の安定操業を阻害する各種の不都合を未然に解
消するために極めて重要なものである。このようなレベ
ル制御の実施に際しては、溶湯レベルをオンラインにて
測定する必要があり、従来においては、図６にその実施
態様を示す方法が一般的に採用されている。By the way, in continuous casting equipment, level control is implemented in which the level of the molten metal inside the mold is measured and the amount of molten metal injected is adjusted to eliminate the deviation between this measurement result and a preset appropriate level. , this level control is
This is extremely important for optimizing the cooling state of the molten metal inside the mold and eliminating various problems that impede the stable operation of continuous casting equipment, such as the formation of surface defects and breakouts on product slabs. be. When implementing such level control, it is necessary to measure the molten metal level online, and conventionally, a method whose embodiment is shown in FIG. 6 has been generally adopted.

【０００４】図示の如く従来の溶湯レベル測定方法は、
鋳型１の上側開口部から溶湯２の表面に臨ませて、該表
面と略直交する軸心を有するセンサコイル２０を配設し
て、これに高周波の励磁電流を通電せしめて行われる。 このとき、導電体である溶湯２の表面には渦電流が誘起
され、これにより発生する磁場の作用により、前記セン
サコイル２０又はこれと同軸的に配した検出用コイルの
インピーダンスが変化するから、この変化を監視するこ
とにより溶湯２の表面位置、即ち、溶湯レベルが特定で
きるのである。なお、溶湯２の表面には、該表面の酸化
防止、該表面からの熱放散防止等を目的として供給され
るパウダ６が堆積しているが、このパウダ６は非導電体
であり、前述した測定の結果に影響を及ぼすことはない
。As shown in the figure, the conventional method for measuring the molten metal level is as follows:
This is carried out by disposing a sensor coil 20 facing the surface of the molten metal 2 from the upper opening of the mold 1 and having an axis substantially perpendicular to the surface, and applying a high-frequency excitation current to the sensor coil 20 . At this time, an eddy current is induced on the surface of the molten metal 2, which is a conductor, and the impedance of the sensor coil 20 or the detection coil disposed coaxially therewith changes due to the action of the magnetic field generated thereby. By monitoring this change, the surface position of the molten metal 2, that is, the molten metal level can be specified. Note that powder 6 is deposited on the surface of the molten metal 2, which is supplied for the purpose of preventing oxidation of the surface, prevention of heat dissipation from the surface, etc., but this powder 6 is a non-conductor and does not meet the above-mentioned conditions. It does not affect the measurement results.

【０００５】[0005]

【発明が解決しようとする課題】ところが、特に小型の
連続鋳造設備においては、鋳型１内部の溶湯２の表面上
に前記センサコイル２０の配設のための十分な空間を確
保し得ないことがあり、更に、この配設により連続鋳造
設備の操業が阻害される虞もあって、従来の溶湯レベル
測定方法の実施が難しい場合が多い。また、センサコイ
ル２０の配設が可能であったとしても、該センサコイル
２０と鋳型１との間に十分な間隔が確保されていないた
めに、センサコイル２０又は前記検出用コイルのインピ
ーダンス変化に導電体である鋳型１の電磁的な影響が生
じ、測定誤差を招来する難点があった。[Problems to be Solved by the Invention] However, especially in small-sized continuous casting equipment, it is difficult to secure sufficient space on the surface of the molten metal 2 inside the mold 1 for arranging the sensor coil 20. Furthermore, this arrangement may impede the operation of the continuous casting equipment, and it is often difficult to implement conventional molten metal level measurement methods. Furthermore, even if the sensor coil 20 can be disposed, a sufficient distance is not secured between the sensor coil 20 and the mold 1, so that impedance changes of the sensor coil 20 or the detection coil may be affected. There was a problem in that electromagnetic effects of the mold 1, which is a conductor, caused measurement errors.

【０００６】更に、幅変更が可能な鋳型１を用いる連続
鋳造設備においては、鋳型１の電磁的な影響を一定に保
つべく、実開平１−１５１９４８号公報に開示されてい
るように、センサコイル２０の平面位置、又はこれと検
出用コイルとの平面位置を鋳型１の幅変更に応じて変更
する必要が生じ、このための複雑な機構を必要とする難
点があった。Furthermore, in continuous casting equipment using a mold 1 whose width can be changed, in order to keep the electromagnetic influence of the mold 1 constant, a sensor coil is used as disclosed in Japanese Utility Model Application Publication No. 1-151948. It becomes necessary to change the planar position of 20 or the planar position of this and the detection coil in accordance with the change in the width of the mold 1, and there is a problem in that a complicated mechanism is required for this purpose.

【０００７】本発明は斯かる事情に鑑みてなされたもの
であり、鋳型内部の溶湯レベルを、該鋳型の大きさの如
何、及び幅変更の有無に拘わらず誤差なく検出でき、特
に小型の連続鋳造設備において有用な溶湯レベル測定方
法を提供することを目的とする。The present invention has been made in view of the above circumstances, and is capable of detecting the molten metal level inside a mold without error, regardless of the size of the mold and whether or not the width has been changed. The purpose of this invention is to provide a method for measuring molten metal level useful in casting equipment.

【０００８】[0008]

【課題を解決するための手段】本発明の第１発明に係る
連続鋳造用鋳型の溶湯レベル測定方法は、連続鋳造設備
の操業中に鋳型の内部にて適正レベルの上下に変動する
溶湯レベルを測定する方法において、前記鋳型の前記適
正レベルを挾んで上下に所定長離隔した位置に一対のコ
イルを埋設し、一方のコイルに低周波の励磁電流を通電
して磁場を生ぜしめ、この磁場により他方のコイルに誘
起される誘導電流を捉え、該誘導電流と前記励磁電流と
の間の位相差及び／　又は強度差を検出し、この検出結
果に基づいて前記溶湯レベルを特定することを特徴とす
る。[Means for Solving the Problems] A method for measuring the level of molten metal in a continuous casting mold according to the first aspect of the present invention measures the level of molten metal that fluctuates above and below an appropriate level inside the mold during the operation of continuous casting equipment. In the measuring method, a pair of coils are buried at positions separated by a predetermined length above and below the appropriate level of the mold, a low-frequency excitation current is passed through one coil to generate a magnetic field, and this magnetic field generates a magnetic field. The method is characterized by capturing an induced current induced in the other coil, detecting a phase difference and/or intensity difference between the induced current and the exciting current, and specifying the molten metal level based on the detection result. do.

【０００９】また本発明の第２発明に係る連続鋳造用鋳
型の溶湯レベル測定方法は、連続鋳造設備の操業中に鋳
型の内部にて適正レベルの上下に変動する溶湯レベルを
測定する方法において、前記鋳型の前記適正レベルを挾
んで上下に所定長離隔した位置に一対のコイルを埋設し
、一方のコイルに相異なる周波数を有する２種の励磁電
流を各別に通電して磁場を生ぜしめ、これらの磁場によ
り他方のコイルに誘起される誘導電流を夫々捉え、これ
らの誘導電流と対応する励磁電流との間の位相差及び／
　又は強度差を各別に検出し、一方の検出結果に基づい
て前記溶湯レベルを特定し、この特定結果を両方の検出
結果間における差異に基づいて温度補正することを特徴
とする。[0009] Furthermore, a method for measuring the level of molten metal in a continuous casting mold according to a second aspect of the present invention is a method for measuring the level of molten metal that fluctuates above and below an appropriate level inside the mold during operation of continuous casting equipment. A pair of coils are buried at positions separated by a predetermined distance above and below the appropriate level of the mold, and two types of excitation currents having different frequencies are separately applied to one coil to generate a magnetic field. The induced currents induced in the other coil by the magnetic field of each are captured, and the phase difference and/or between these induced currents and the corresponding excitation current are calculated.
Alternatively, the method is characterized in that the intensity difference is detected separately, the molten metal level is specified based on one detection result, and this identification result is temperature-corrected based on the difference between both detection results.

【００１０】0010

【作用】第１発明においては、連続鋳造用の鋳型に、適
正な溶湯レベル位置を挾んで一対のコイルを埋設し、一
方のコイルを低周波の励磁電流の通電により磁場を発生
する送信コイルとした場合、他方のコイルは鋳型、溶湯
及び両者間の間隙を伝播する前記磁場の作用により誘導
電流が誘起される受信コイルとなる。このとき、受信コ
イルに達する前記磁場のエネルギは、主として溶湯内の
伝播長さの長短、即ち、溶湯レベルの高低に応じて変化
し、これにより受信コイルに誘起される誘導電流に位相
遅れ及び強度低下が生じ、この誘導電流と送信コイルの
励磁電流との間の位相差及び／又は強度差の検出により
溶湯レベルが特定される。[Operation] In the first invention, a pair of coils are embedded in a mold for continuous casting at appropriate molten metal level positions, and one coil is used as a transmitting coil that generates a magnetic field by passing a low-frequency excitation current. In this case, the other coil becomes a receiving coil in which an induced current is induced by the action of the magnetic field propagating through the mold, the molten metal, and the gap between them. At this time, the energy of the magnetic field that reaches the receiving coil changes mainly depending on the length of propagation within the molten metal, that is, the height of the molten metal level. A drop occurs and the molten metal level is determined by detecting the phase and/or intensity difference between this induced current and the excitation current of the transmitter coil.

【００１１】また第２発明においては、前記送信コイル
に周波数の異なる２種の励磁電流を各別に通電し、一方
の励磁電流の通電時における前記位相差及び／又は強度
差の検出結果により溶湯レベルを特定する一方、両方の
通電時における前記位相差及び／又は強度差の検出結果
間に生じる差異に基づく温度補正を実施し、前記特定結
果中に存在する鋳型温度の変動による誤差を排除する。Further, in the second invention, two types of excitation currents having different frequencies are separately applied to the transmitting coil, and the molten metal level is determined based on the detection result of the phase difference and/or intensity difference when one of the excitation currents is applied. While specifying, temperature correction is performed based on the difference that occurs between the detection results of the phase difference and/or intensity difference during both energization, and errors due to variations in mold temperature that exist in the specified results are eliminated.

【００１２】0012

【実施例】以下本発明をその実施例を示す図面に基づい
て詳述する。図１は本発明の第１発明に係る連続鋳造用
鋳型の溶湯レベル測定方法（以下第１の方法という）の
実施状態を示す模式的ブロック図である。DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to drawings showing embodiments thereof. FIG. 1 is a schematic block diagram showing the implementation state of a method for measuring the level of molten metal in a continuous casting mold (hereinafter referred to as the first method) according to the first aspect of the present invention.

【００１３】図中１は、上下に開口を有し筒形をなす連
続鋳造用の鋳型である。該鋳型１には、これの上側開口
部から内部に適長侵入せしめた浸漬ノズル４を経て溶湯
２が注入されており、この溶湯２は、鋳型１内に滞留す
る間に、該鋳型１の水冷された内壁との接触により冷却
（１次冷却）され、凝固シェル５ａにてその外側を被覆
された鋳片５となり、鋳型１の下側開口部から下方に連
続的に引き抜かれる。Reference numeral 1 in the figure indicates a continuous casting mold having a cylindrical shape with openings at the top and bottom. A molten metal 2 is injected into the mold 1 through an immersion nozzle 4 that penetrates into the mold 1 by an appropriate length from an upper opening thereof, and while the molten metal 2 stays in the mold 1, The slab 5 is cooled (primary cooling) by contact with the water-cooled inner wall, and the outside of the slab 5 is covered with a solidified shell 5a, and is continuously drawn downward from the lower opening of the mold 1.

【００１４】鋳型１の下側には、鋳片５の引き抜き経路
に沿って多数の冷却水ノズル（図示せず）が配してあり
、鋳片５は、これらの冷却水ノズルからの噴射水により
更に冷却（２次冷却）されて、内側に至るまで凝固が進
行した後に所望の長さに切断され、圧延等の後工程に素
材として送給される。なお、鋳型１内部の溶湯２の表面
には、該表面の酸化防止及び該表面からの熱放散の防止
のためにパウダ６が供給されており、このパウダ６は、
溶湯２との接触により溶融し、鋳型１の内壁に沿って鋳
片５との間の間隙３に流入して、該鋳片５の引き抜きに
際しての潤滑剤としての機能も果たす。A large number of cooling water nozzles (not shown) are arranged below the mold 1 along the drawing path of the slab 5, and the slab 5 receives water jetted from these cooling water nozzles. After being further cooled (secondary cooling) and solidified to the inside, it is cut into a desired length and sent as a raw material to subsequent processes such as rolling. Incidentally, powder 6 is supplied to the surface of the molten metal 2 inside the mold 1 in order to prevent oxidation of the surface and prevent heat dissipation from the surface.
It melts upon contact with the molten metal 2, flows along the inner wall of the mold 1 into the gap 3 between the slab 5, and also functions as a lubricant when the slab 5 is pulled out.

【００１５】以上の如き構成の連続鋳造設備の操業に際
し、鋳型１内の溶湯２の表面位置、即ち溶湯レベルは、
浸漬ノズル４からの溶湯２の注入量と、鋳片５の引抜き
速度とのバランスにより定まる。この溶湯レベルをオン
ラインにて測定すべく実施される本発明の第１の方法は
、図示の如く、鋳型１の内壁に面して一対のコイル、即
ち、送信コイル１０及び受信コイル１１を埋設して実施
される。[0015] When operating the continuous casting equipment configured as described above, the surface position of the molten metal 2 in the mold 1, that is, the molten metal level, is as follows:
It is determined by the balance between the amount of molten metal 2 injected from the immersion nozzle 4 and the drawing speed of the slab 5. The first method of the present invention, which is carried out to measure the molten metal level online, involves embedding a pair of coils, namely a transmitting coil 10 and a receiving coil 11, facing the inner wall of a mold 1, as shown in the figure. will be implemented.

【００１６】送信コイル１０は、図中に一点鎖線にて示
す溶湯２の適正レベルＬよりも上方に位置して埋設され
ており、また受信コイル１１は、鋳型１の下方に前記受
信コイル１０から所定長離隔し、前記適正レベルＬより
も下方に位置して埋設されている。なお、送信コイル１
０及び受信コイル１１の埋設態様はこれに限るものでは
なく、前記適正レベルＬを挾んで上下に所定長離隔して
おればよく、受信コイル１１を上とし、送信コイル１０
を下としてもよい。The transmitting coil 10 is buried above the appropriate level L of the molten metal 2 shown by the dashed line in the figure, and the receiving coil 11 is located below the mold 1 from the receiving coil 10. They are buried at a predetermined distance apart and located below the appropriate level L. In addition, transmitting coil 1
0 and the receiving coil 11 are not limited to this, but it is sufficient that they are spaced apart by a predetermined distance vertically with the appropriate level L between them, with the receiving coil 11 at the top and the transmitting coil 10
You can also lower it.

【００１７】さて送信コイル１０は、発振回路１２に接
続してあり、該発振回路１２の出力である低周波電流の
通電により励磁されて、その周辺に磁場を形成する作用
をなす。このとき受信コイル１１には、送信コイル１０
の励磁により発生する磁場エネルギが後述の如く伝播し
て誘導電流が誘起され、この誘導電流は、増幅器１３を
経て位相差検出器１４に与えられている。The transmitting coil 10 is connected to an oscillation circuit 12, and is excited by the low-frequency current output from the oscillation circuit 12 to form a magnetic field around it. At this time, the receiving coil 11 includes the transmitting coil 10
The magnetic field energy generated by the excitation propagates as described later and induces an induced current, and this induced current is provided to the phase difference detector 14 via the amplifier 13.

【００１８】位相差検出器１４には、前記発振回路１２
の出力もまた与えられており、該位相差検出器１４は、
送信コイル１０に加えられる励磁電流と受信コイル１１
に誘起される誘導電流との間の位相差を求め、この結果
を演算部１５に出力する動作をなす。The phase difference detector 14 includes the oscillation circuit 12
The output of the phase difference detector 14 is also given, and the phase difference detector 14 is
Excitation current applied to transmitting coil 10 and receiving coil 11
The phase difference between the induced current and the induced current is determined, and the result is output to the arithmetic unit 15.

【００１９】演算部１５は、例えば、鋳型１内での溶湯
２のレベルを種々に変更して予め実施された試験結果に
より得られた溶湯２のレベルと前記位相差との対応関係
を記憶しており、位相差検出器１４からの入力をこの対
応関係に適用して、溶湯２の現状のレベルを演算する。 演算部１５の演算結果は、例えば、該演算部１５の出力
側に接続された　ＣＲＴディスプレイ等の表示器１６に
表示させ、オペレータによる操業管理に利用するように
してもよく、またより直接的に、浸漬ノズル４からの溶
湯２の注入量の自動調節、及び／又は鋳片５の引抜き速
度の自動調節に用いるようにしてもよい。The calculation unit 15 stores, for example, the correspondence between the level of the molten metal 2 and the phase difference obtained from test results conducted in advance by variously changing the level of the molten metal 2 in the mold 1. The input from the phase difference detector 14 is applied to this correspondence to calculate the current level of the molten metal 2. The calculation results of the calculation unit 15 may be displayed on a display 16 such as a CRT display connected to the output side of the calculation unit 15, and may be used for operation management by the operator, or may be used more directly. , it may be used to automatically adjust the amount of molten metal 2 injected from the immersion nozzle 4 and/or automatically adjust the drawing speed of the slab 5.

【００２０】以上の如く第１の方法は、鋳型１の内壁に
面して該鋳型１内部の適正な溶湯レベルＬを挾み、上下
に所定長離隔させて一対のコイル、即ち、送信コイル１
０及び受信コイル１１を埋設することにより実施され、
送信コイル１０への低周波の励磁電流を通電して磁場を
発生させ、この磁場の作用により受信コイル１１に誘起
される誘導電流を捉え、これと前記励磁電流との位相差
を検出し、この検出結果に基づいて溶湯２の現状のレベ
ルを特定する方法であり、次にこの手順により溶湯２の
レベルが得られる原理につき説明する。As described above, in the first method, a pair of coils, ie, transmitting coils 1, are placed between the appropriate molten metal level L inside the mold 1 facing the inner wall of the mold 1 and spaced apart from each other by a predetermined distance vertically.
0 and the receiving coil 11 are buried,
A low-frequency excitation current is passed through the transmitting coil 10 to generate a magnetic field, the induced current induced in the receiving coil 11 by the action of this magnetic field is captured, and the phase difference between this and the excitation current is detected. This is a method of specifying the current level of the molten metal 2 based on the detection result.Next, the principle of obtaining the level of the molten metal 2 through this procedure will be explained.

【００２１】図２及び図３は、測定原理の説明図である
。送信コイル１０への前述の如き励磁電流の印加に応じ
て発生する磁場のエネルギは、これらの図中に白抜矢符
にて示す如く、鋳型１内を直接伝播する第１の経路、鋳
型１と溶湯２との間の間隙３を伝播する第２の経路、及
び溶湯２の内部を伝播する第３の経路を夫々経て受信コ
イル１１に達し、該受信コイル１１に誘導電流が誘起さ
れるが、このとき、鋳型１の内壁は銅板であり、溶湯２
に比較して高い導電率を有することから、前記第１の経
路を伝播する磁場エネルギの減衰程度は大きく、送信コ
イル１０と受信コイル１１との離隔距離が所定長を超え
ると、第１の経路を経て受信コイル１１に達する磁場エ
ネルギは無視出来るレベルとなる。FIGS. 2 and 3 are explanatory diagrams of the measurement principle. The energy of the magnetic field generated in response to the application of the above-mentioned excitation current to the transmitting coil 10 is propagated directly through the mold 1 through a first path, as shown by the open arrow in these figures. The current reaches the receiving coil 11 through a second path that propagates through the gap 3 between the molten metal 2 and the molten metal 2, and a third path that propagates inside the molten metal 2, and an induced current is induced in the receiving coil 11. , at this time, the inner wall of the mold 1 is a copper plate, and the molten metal 2
Since the magnetic field energy propagating through the first path has a high conductivity compared to The magnetic field energy that reaches the receiving coil 11 through this becomes a negligible level.

【００２２】また、間隙３からなる第２の経路には非導
電体であるパウダ６が充填され、この第２の経路を伝播
する磁場エネルギの減衰は少ないが、間隙３の寸法は通
常小さいから、第２の経路を伝播するエネルギの絶対量
は、第３の経路、即ち、溶湯２内を伝播する磁場エネル
ギの絶対量に比して十分に小さい。即ち、受信コイル１
１に達してこのコイル１１に誘導電流を生ぜしめる磁場
エネルギは第３の経路を伝播する磁場エネルギに支配さ
れることになる。Furthermore, the second path consisting of the gap 3 is filled with powder 6, which is a non-conductor, and the attenuation of the magnetic field energy propagating through this second path is small, but since the dimensions of the gap 3 are usually small, , the absolute amount of energy propagating through the second path is sufficiently smaller than the absolute amount of magnetic field energy propagating through the third path, that is, within the molten metal 2. That is, receiving coil 1
The magnetic field energy that reaches 1 and causes an induced current in this coil 11 will be dominated by the magnetic field energy that propagates through the third path.

【００２３】ここで溶湯２のレベルが、図２に示す如く
、適正レベルＬよりも上にある場合と、図３に示す如く
、適正レベルＬよりも下にある場合とを比較すると、前
者の場合、第３の経路中での溶湯２の占める割合が多く
、後者の場合、溶湯２以外の部分、即ち溶湯２上部の空
間の占める割合が多い。また溶湯２内を磁場エネルギが
伝播するとき、該溶湯２が導電体であることから、この
伝播長さに応じた位相遅れ及びエネルギの減衰が生じる
。Comparing the case where the level of the molten metal 2 is above the proper level L as shown in FIG. 2 and the case where it is below the proper level L as shown in FIG. In this case, the proportion of the molten metal 2 in the third path is large, and in the latter case, the proportion of the space other than the molten metal 2, that is, the space above the molten metal 2, is large. Furthermore, when the magnetic field energy propagates within the molten metal 2, since the molten metal 2 is a conductor, a phase delay and energy attenuation occur depending on the propagation length.

【００２４】従って、このような磁場エネルギの受信に
応じて受信コイル１１に誘起される誘導電流には、第３
の経路中における溶湯２の占める部分の長さ、即ち該溶
湯２のレベルの高低に応じた位相遅れ及び強度低下が生
じる。即ち、溶湯２の種々のレベルにおいて生じる位相
遅れ量を調べ、この結果を前記演算部１５に記憶させて
おけば、位相差検出器１４から前述の如く与えられる位
相差を用いて溶湯２の現状のレベルを演算することが可
能となる。またこのとき、送信コイル１０と受信コイル
１１との離隔距離を前記第１の経路の伝播エネルギが十
分小さくなるように選定すれば、受信コイル１１の受信
結果における鋳型１による電磁的な影響は排除されるか
ら、前述した手順により溶湯２のレベルの正確な特定が
可能となる。[0024] Therefore, the induced current induced in the receiving coil 11 in response to reception of such magnetic field energy includes a third
A phase delay and a decrease in strength occur depending on the length of the portion occupied by the molten metal 2 in the path, that is, the level of the molten metal 2. That is, by examining the amount of phase delay occurring at various levels of the molten metal 2 and storing the results in the calculation section 15, the current state of the molten metal 2 can be determined using the phase difference given from the phase difference detector 14 as described above. It becomes possible to calculate the level of Also, at this time, if the separation distance between the transmitting coil 10 and the receiving coil 11 is selected so that the propagation energy of the first path is sufficiently small, the electromagnetic influence of the mold 1 on the reception result of the receiving coil 11 can be eliminated. Therefore, the level of the molten metal 2 can be accurately specified by the above-described procedure.

【００２５】送信コイル１０及び受信コイル１１の鋳型
１の内壁面からの埋設深さは適宜に設定でき、またこれ
らの埋設態様も限定されないが、高温の溶湯２からの熱
放射に伴う損傷を回避するため、図４に示す如き埋設態
様が採用される。The buried depth of the transmitting coil 10 and the receiving coil 11 from the inner wall surface of the mold 1 can be set as appropriate, and the manner in which they are buried is not limited, but damage caused by heat radiation from the high-temperature molten metal 2 can be avoided. Therefore, an embedding mode as shown in FIG. 4 is adopted.

【００２６】本図に示す如く、送信コイル１０及び受信
コイル１１はいずれも、矢符にて示すように冷却水が循
環される水冷ケース３０内に収納して、鋳型１の内壁か
ら１０ｍｍ以上離して埋設するのがよく、これにより、
溶湯２からの熱放射に伴う損傷を略完全に排除できる。 また送信コイル１０及び受信コイル１１の直径は２０ｍ
ｍ程度であり、図中の３１は、外部からの給電又は外部
への出力のためのコイル線である。As shown in this figure, both the transmitter coil 10 and the receiver coil 11 are housed in a water-cooled case 30 in which cooling water is circulated, as shown by arrows, and are spaced at least 10 mm from the inner wall of the mold 1. It is best to bury the
Damage caused by heat radiation from the molten metal 2 can be almost completely eliminated. Also, the diameter of the transmitting coil 10 and receiving coil 11 is 20 m.
31 in the figure is a coil wire for external power supply or external output.

【００２７】なお、前述の如く、第３の経路を経て伝播
する磁場エネルギには、該経路中における溶湯２の占め
る部分の長さ、即ち、溶湯２のレベルの高低に応じた減
衰が生じるから、受信コイル１１には、溶湯２のレベル
に応じた強度の誘導電流が誘起される。従って、前記位
相差検出器１４に換えて強度差検出器を設け、受信コイ
ル１１における誘導電流と送信コイル１０に印加される
励磁電流の強度差を演算部１５に与えることにより溶湯
２の現状のレベルを特定することも可能であり、このこ
ともまた本発明の範囲に含まれる。As mentioned above, the magnetic field energy propagating through the third path is attenuated depending on the length of the portion occupied by the molten metal 2 in the third path, that is, the level of the molten metal 2. , an induced current having an intensity corresponding to the level of the molten metal 2 is induced in the receiving coil 11. Therefore, an intensity difference detector is provided in place of the phase difference detector 14, and the intensity difference between the induced current in the receiving coil 11 and the excitation current applied to the transmitting coil 10 is provided to the calculating section 15, thereby determining the current state of the molten metal 2. It is also possible to specify the level and this is also within the scope of the invention.

【００２８】また、送信コイル１０に印加する励磁電流
の周波数は、特に限定するものではないが、現段階にお
いては、５０〜１０００Ｈｚ程度の周波数の採用により
好結果が得られている。更にこの範囲の周波数を採用す
る場合、送信コイル１０と受信コイル１１との間の離隔
距離は、１００ｍｍ　程度に設定するのが適当であり、
これにより前記適正レベルＬの上下に５０ｍｍの範囲内
でのレベル測定が可能となる。この測定範囲は連続鋳造
設備の操業管理上において十分なものである。Further, the frequency of the excitation current applied to the transmitting coil 10 is not particularly limited, but at present good results have been obtained by adopting a frequency of about 50 to 1000 Hz. Furthermore, when using frequencies in this range, it is appropriate to set the separation distance between the transmitting coil 10 and the receiving coil 11 to about 100 mm.
This makes it possible to measure the level within a range of 50 mm above and below the appropriate level L. This measurement range is sufficient for operational management of continuous casting equipment.

【００２９】さて、以上の説明において前記第１の経路
、即ち鋳型１の内部を直接伝播する磁場のエネルギは、
該鋳型１の温度によって異なり、前記第１の方法におい
て特定される溶湯レベルの測定結果中には、鋳型１の温
度変動の影響が生じる。本発明の第２発明に係る連続鋳
造用鋳型の溶湯レベル測定方法（以下第２の方法という
）は、この温度変動の影響を排除するための方法であり
、その実施態様を図５に示す。Now, in the above explanation, the energy of the magnetic field directly propagating through the first path, that is, inside the mold 1, is:
It varies depending on the temperature of the mold 1, and the influence of the temperature fluctuation of the mold 1 occurs in the measurement result of the molten metal level specified in the first method. The method for measuring the molten metal level in a continuous casting mold according to the second aspect of the present invention (hereinafter referred to as the second method) is a method for eliminating the influence of this temperature fluctuation, and an embodiment thereof is shown in FIG.

【００３０】本図に示す如く第２の方法は、第１の方法
と同様、溶湯２の適正レベルＬを挾み、鋳型１の内壁に
面して送信コイル１０及び受信コイル１１を埋設し、こ
の送信コイル１０を、レベル特定のための低周波電流を
出力する前記発振回路１２と、これよりも低い周波数を
有する低周波電流を出力する発振回路１７とに、切換ス
イッチ１８を介して接続して実施される。As shown in the figure, the second method, similar to the first method, involves sandwiching the appropriate level L of the molten metal 2 and burying the transmitting coil 10 and the receiving coil 11 facing the inner wall of the mold 1. This transmitting coil 10 is connected via a changeover switch 18 to the oscillation circuit 12 that outputs a low frequency current for level specification and to the oscillation circuit 17 that outputs a low frequency current having a lower frequency. will be implemented.

【００３１】即ち送信コイル１０は、切換スイッチ１８
の切換位置に応じて発振回路１２又は発振回路１７の出
力が与えられ、相異なる周波数を有する２種の励磁電流
により各別に励磁されて磁場を発生することになり、こ
れらの磁場は、前述した第１，第２，第３の経路を経て
受信コイル１１に伝播し、該受信コイル１１に誘導電流
が誘起される。これらの誘導電流と対応する励磁電流と
の間の位相差は、前述した如く位相差検出器１４にて検
出されて演算部１５に与えられる。That is, the transmitting coil 10 is connected to the changeover switch 18.
The output of the oscillation circuit 12 or the oscillation circuit 17 is given depending on the switching position of the oscillation circuit 12, and each of them is excited by two types of excitation currents having different frequencies to generate a magnetic field. It propagates to the receiving coil 11 via the first, second, and third paths, and an induced current is induced in the receiving coil 11. The phase differences between these induced currents and the corresponding excitation currents are detected by the phase difference detector 14 and provided to the calculation unit 15 as described above.

【００３２】位相差検出器１４での検出対象となる位相
差θは、前述した如く、第３の経路における溶湯２の占
める部分の長さＸに依存すると共に、第１の経路の温度
、即ち鋳型１の温度Ｔにもまた依存し、両者を変数とす
る次式により表される。θ＝ａＴ＋ｂＸ＋ｃ　　　　　
　　　…（１）As described above, the phase difference θ to be detected by the phase difference detector 14 depends on the length X of the portion occupied by the molten metal 2 in the third path, and also depends on the temperature of the first path, that is, It also depends on the temperature T of the mold 1, and is expressed by the following equation using both as variables. θ=aT+bX+c
...(1)

【００３３】この式中のａは、鋳型１の温度の影響を示
す温度係数、ｂは、溶湯２のレベルの高低の影響を示す
レベル係数、ｃは定数であり、これらは、送信コイル１
０の励磁周波数に応じて異なり、この周波数の低下に伴
って温度係数ａは増大し、レベル係数ｂは逆に増大する
。 即ち、位相差検出器１４にて検出される位相差に生じる
鋳型１の温度の影響は、検出コイル１０の励磁電流の周
波数が低いほど顕著に現れる。In this formula, a is a temperature coefficient indicating the influence of the temperature of the mold 1, b is a level coefficient indicating the influence of the level of the molten metal 2, and c is a constant.
It varies depending on the excitation frequency of 0, and as the frequency decreases, the temperature coefficient a increases, and the level coefficient b increases conversely. That is, the effect of the temperature of the mold 1 on the phase difference detected by the phase difference detector 14 becomes more pronounced as the frequency of the excitation current of the detection coil 10 is lower.

【００３４】前記温度係数ａ、レベル係数ｂ及び定数ｃ
は、発振回路１２，１７の出力周波数の夫々に対し実験
により求め、この結果は演算部１５に記憶させてある。 従って、切換スイッチ１８の切換えにより発振回路１２
，１７の各一回の出力を送信コイル１０に与え、これら
各場合における送信コイル１０の励磁電流と、受信コイ
ル１１に誘起される誘導電流との位相差が演算部１５に
与えられる。演算部１５は、これら夫々を対応する温度
係数ａ、レベル係数ｂ及び定数ｃを有する（１）式に代
入し、これにより得られる連立方程式の解として、現状
の溶湯レベルを鋳型１の現状の温度Ｔと共に特定する。[0034] The temperature coefficient a, the level coefficient b and the constant c
is determined by experiment for each of the output frequencies of the oscillation circuits 12 and 17, and the results are stored in the calculation section 15. Therefore, by switching the changeover switch 18, the oscillation circuit 12
. The calculation unit 15 substitutes each of these into equation (1) having the corresponding temperature coefficient a, level coefficient b, and constant c, and calculates the current molten metal level of the mold 1 as a solution to the resulting simultaneous equations. Specify together with temperature T.

【００３５】このようにして鋳型１の温度Ｔを特定した
後は、切換スイッチ１８を発振回路１２側に切換えた状
態を継続し、該発振回路１２の出力によるレベル測定用
の励磁電流にて送信コイル１０を励磁し、受信コイル１
１に誘起される誘導電流との位相差を検出して、これを
、鋳型１の温度Ｔを既知の値として含む（１）式に代入
することにより、温度補正がなされた溶湯レベルを求め
ることができる。After determining the temperature T of the mold 1 in this manner, the changeover switch 18 is kept switched to the oscillation circuit 12 side, and the excitation current for level measurement is transmitted by the output of the oscillation circuit 12. Excite coil 10, and receive coil 1
By detecting the phase difference with the induced current induced in mold 1 and substituting it into equation (1) that includes the temperature T of mold 1 as a known value, the temperature-corrected molten metal level is determined. Can be done.

【００３６】切換スイッチ１８の発振回路１７側への切
換えは、発振回路１２の所定回数の出力がなされた都度
行い、このとき鋳型１の現状の温度Ｔが同様の手順にて
新たに特定され、（１）式中のＴの値の更新に用いられ
る。切換スイッチ１８の発振回路１７側への切換えタイ
ミングは、鋳型１において予想される温度変化の程度に
応じて適宜に設定すればよい。なお、切換スイッチ１８
の切換え操作は、手動により行ってもよく、また演算部
１５からの指令により自動的に行わせてもよい。The changeover switch 18 is switched to the oscillation circuit 17 side each time the oscillation circuit 12 outputs a predetermined number of times, and at this time, the current temperature T of the mold 1 is newly specified in the same procedure. It is used to update the value of T in equation (1). The timing of switching the changeover switch 18 to the oscillation circuit 17 side may be appropriately set depending on the degree of temperature change expected in the mold 1. In addition, the changeover switch 18
The switching operation may be performed manually or may be performed automatically by a command from the calculation unit 15.

【００３７】このように第２の方法においては、送信コ
イル１０に相異なる周波数を有する２種の励磁電流を各
別に通電して磁場を生ぜしめ、これらの磁場により受信
コイル１１に誘起される誘導電流を夫々捉え、これらの
誘導電流と対応する励磁電流との間の位相差を各別に検
出することにより、一方の検出結果に基づいて特定され
る溶湯レベルが両方の検出結果間における差異に基づい
て確実に温度補正されることになり、鋳型１の温度変動
による誤差を解消することができ、測定精度の更なる向
上が図れる。As described above, in the second method, two types of excitation currents having different frequencies are separately applied to the transmitting coil 10 to generate a magnetic field, and the induction induced in the receiving coil 11 by these magnetic fields is By capturing each current and detecting the phase difference between these induced currents and the corresponding excitation current separately, the molten metal level determined based on one detection result can be determined based on the difference between both detection results. As a result, the temperature can be reliably corrected, and errors caused by temperature fluctuations in the mold 1 can be eliminated, and measurement accuracy can be further improved.

【００３８】送信コイル１０に印加する温度補正用の励
磁電流の周波数は、レベル測定用のそれよりも高い周波
数を採用することも可能であるが、前述した如く鋳型１
の温度の影響が励磁電流の周波数の低下と共に顕著に生
じることから、より低い周波数の採用が望ましい。現状
においては、レベル測定用の励磁電流の周波数を前述の
如く５０〜１０００Ｈｚとした場合、これよりも低い５
〜５０Ｈｚなる周波数を有する温度補正用の励磁電流の
採用により良好な結果が得られている。The frequency of the excitation current for temperature correction applied to the transmitting coil 10 can be higher than that for level measurement, but as described above,
Since the influence of temperature becomes more pronounced as the frequency of the excitation current decreases, it is desirable to use a lower frequency. Currently, when the frequency of the excitation current for level measurement is set to 50 to 1000Hz as mentioned above, the
Good results have been obtained by employing an excitation current for temperature compensation having a frequency of ~50 Hz.

【００３９】なお以上の如く実施される第２の方法にお
いても、前記第１の方法と同様、励磁電流と誘導電流と
の位相差に変えて強度差を用いることも可能である。In the second method carried out as described above, it is also possible to use an intensity difference instead of a phase difference between the excitation current and the induced current, as in the first method.

【００４０】[0040]

【発明の効果】以上詳述した如く本発明の第１の方法に
おいては、連続鋳造用の鋳型に適正な溶湯レベルを挾ん
で一対のコイルを埋設し、これらの一方を低周波の励磁
電流の通電により磁場を発生する送信コイルとし、鋳型
及びこれの内部の溶湯、並びに両者間の間隙を伝播する
この磁場のエネルギにより他方のコイルに誘起される誘
導電流を捉えたとき、前記磁場エネルギの伝播経路の相
違に応じて前記誘導電流に生じる位相変化又は強度変化
に基づいて溶湯レベルが特定されるから、鋳型の上部が
狭い場合、鋳型の幅変更が行われる場合であっても、鋳
型の電磁的な影響を受けることなく、また操業を阻害す
ることなく、高精度での溶湯レベルの測定が可能となる
。Effects of the Invention As detailed above, in the first method of the present invention, a pair of coils are embedded in a continuous casting mold with an appropriate level of molten metal, and one of the coils is energized by a low-frequency excitation current. When a transmission coil is used to generate a magnetic field when energized, and an induced current induced in the other coil by the energy of this magnetic field propagating through the mold, the molten metal inside it, and the gap between the two is captured, the propagation of the magnetic field energy Since the molten metal level is determined based on the phase change or intensity change that occurs in the induced current depending on the path difference, the mold electromagnetic This makes it possible to measure the molten metal level with high accuracy without being affected by the situation or disrupting operations.

【００４１】また、送信コイルの励磁を相異なる２種の
周波数を有する励磁電流により行う本発明の第２の方法
においては、夫々における位相差又は強度差に基づいて
確実な温度補正がなされ、鋳型の温度変動に影響される
ことなく溶湯レベルを測定でき、測定精度の更なる向上
が図れる。Furthermore, in the second method of the present invention in which the transmitter coil is excited by excitation currents having two different frequencies, reliable temperature correction is performed based on the phase difference or intensity difference in each, and the mold The molten metal level can be measured without being affected by temperature fluctuations, further improving measurement accuracy.

【００４２】従って本発明方法により得られた溶湯レベ
ルを用いて連続鋳造設備の湯面レベル制御を実施した場
合、高精度での溶湯レベルの把握により、製品鋳片の品
質向上が図れ、またブレークアウトの発生を未然に防止
し得る等、本発明は優れた効果を奏する。Therefore, when the molten metal level obtained by the method of the present invention is used to control the molten metal level in continuous casting equipment, the quality of the product slab can be improved by grasping the molten metal level with high accuracy, and the break The present invention has excellent effects such as being able to prevent the occurrence of outs.

【図面の簡単な説明】[Brief explanation of the drawing]

【図１】本発明の第１発明の実施状態を示す模式的ブロ
ック図である。FIG. 1 is a schematic block diagram showing an implementation state of a first invention of the present invention.

【図２】本発明方法の測定原理の説明図である。FIG. 2 is an explanatory diagram of the measurement principle of the method of the present invention.

【図３】本発明方法の測定原理の説明図である。FIG. 3 is an explanatory diagram of the measurement principle of the method of the present invention.

【図４】送信コイル及び受信コイルの望ましい埋設態様
を示す模式図である。FIG. 4 is a schematic diagram showing a desirable manner of embedding a transmitting coil and a receiving coil.

【図５】本発明の第２発明の実施状態を示す模式的ブロ
ック図である。FIG. 5 is a schematic block diagram showing an implementation state of the second invention of the present invention.

【図６】従来の溶湯レベル測定方法の実施状態を示す模
式図である。FIG. 6 is a schematic diagram showing an implementation state of a conventional molten metal level measuring method.

【符号の説明】[Explanation of symbols]

１　　鋳型 ２　　溶湯 ５　　鋳片 １０　　送信コイル １１　　受信コイル １２　　発振回路 １４　　位相差検出器 １５　　演算部 １７　　発振回路 1 Mold 2 Molten metal 5 Slab 10 Transmission coil 11 Receiving coil 12 Oscillation circuit 14 Phase difference detector 15 Arithmetic unit 17 Oscillation circuit

Claims (2)

【特許請求の範囲】[Claims] 【請求項１】　　連続鋳造設備の操業中に鋳型の内部に
て適正レベルの上下に変動する溶湯レベルを測定する方
法において、前記鋳型の前記適正レベルを挾んで上下に
所定長離隔した位置に一対のコイルを埋設し、一方のコ
イルに低周波の励磁電流を通電して磁場を生ぜしめ、こ
の磁場により他方のコイルに誘起される誘導電流を捉え
、該誘導電流と前記励磁電流との間の位相差及び／　又
は強度差を検出し、この検出結果に基づいて前記溶湯レ
ベルを特定することを特徴とする連続鋳造用鋳型の溶湯
レベル測定方法。1. A method for measuring the level of molten metal that fluctuates above and below an appropriate level inside a mold during operation of continuous casting equipment, wherein a pair of molten metals are placed at positions separated by a predetermined length above and below the appropriate level of the mold. A low-frequency excitation current is passed through one coil to generate a magnetic field, the induced current induced in the other coil by this magnetic field is captured, and the relationship between the induced current and the excitation current is 1. A method for measuring a molten metal level in a continuous casting mold, comprising detecting a phase difference and/or an intensity difference, and specifying the molten metal level based on the detection result. 【請求項２】　　連続鋳造設備の操業中に鋳型の内部に
て適正レベルの上下に変動する溶湯レベルを測定する方
法において、前記鋳型の前記適正レベルを挾んで上下に
所定長離隔した位置に一対のコイルを埋設し、一方のコ
イルに相異なる周波数を有する２種の励磁電流を各別に
通電して磁場を生ぜしめ、これらの磁場により他方のコ
イルに誘起される誘導電流を夫々捉え、これらの誘導電
流と対応する励磁電流との間の位相差及び／　又は強度
差を各別に検出し、一方の検出結果に基づいて前記溶湯
レベルを特定し、この特定結果を両方の検出結果間にお
ける差異に基づいて温度補正することを特徴とする連続
鋳造用鋳型の溶湯レベル測定方法。2. A method for measuring a molten metal level that fluctuates above and below an appropriate level inside a mold during the operation of continuous casting equipment, wherein a pair of molten metals are placed at positions separated by a predetermined length above and below the appropriate level of the mold. two types of excitation currents with different frequencies are applied to one coil separately to generate a magnetic field, and the induced currents induced in the other coil by these magnetic fields are captured respectively. Detecting the phase difference and/or intensity difference between the induced current and the corresponding excitation current separately, determining the molten metal level based on one detection result, and converting this identification result into the difference between both detection results. A method for measuring the level of molten metal in a mold for continuous casting, characterized in that the temperature is corrected based on the temperature.