JPH10225751A - Method for controlling molten metal surface level - Google Patents

Method for controlling molten metal surface level

Info

Publication number
JPH10225751A
JPH10225751A JP2925297A JP2925297A JPH10225751A JP H10225751 A JPH10225751 A JP H10225751A JP 2925297 A JP2925297 A JP 2925297A JP 2925297 A JP2925297 A JP 2925297A JP H10225751 A JPH10225751 A JP H10225751A
Authority
JP
Japan
Prior art keywords
level
molten metal
hot water
water supply
surface level
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.)
Granted
Application number
JP2925297A
Other languages
Japanese (ja)
Other versions
JP3557829B2 (en
Inventor
Fumisato Ishihara
史学 石原
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.)
Nippon Steel Corp
Original Assignee
Sumitomo Metal Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Metal Industries Ltd filed Critical Sumitomo Metal Industries Ltd
Priority to JP02925297A priority Critical patent/JP3557829B2/en
Publication of JPH10225751A publication Critical patent/JPH10225751A/en
Application granted granted Critical
Publication of JP3557829B2 publication Critical patent/JP3557829B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Abstract

PROBLEM TO BE SOLVED: To shorten the time needed to raise up molten metal surface level in a molten metal pool part of a continuous casting apparatus to a target molten metal surface level. SOLUTION: After setting each setting value, a nozzle full-opening command is given to a nozzle control part 4, and when the molten metal surface level of the molten metal pool part 6 reaches a reference molten metal surface level Lsv2, the opening degree of a molten metal supplying nozzle is set to the obtd. opening degree SB of the nozzle. Thereafter, a changing quantity ΔST of the opening degree of the nozzle is obtd. and the nozzle is contracted according to this obtd. quantity, and at the time when the ratio γ of the molten metal surface level measured value Lpv(t) to a target molten metal surface level Lsv1 is in the range of 90-110%, or when the time reaches the predetermined convergence judge time Ts, the molten metal surface level control is switched to the well-known molten metal surface level control by a PID control method for example.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は連続鋳造装置の操業
開始に際し、さらに詳しくは湯溜まり部への溶融金属の
注入開始からその湯溜まり部内の溶融金属の湯面レベル
が目標湯面レベルに達するまでの時間を短縮する方法に
関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the start of operation of a continuous casting apparatus, and more specifically, from the start of injection of molten metal into a pool, the level of the molten metal in the pool reaches a target level. How to reduce the time to.

【0002】[0002]

【従来の技術】薄肉鋳片の連続鋳造方法は湯溜まり部に
注入された溶融金属を前記湯溜まり部の壁面に設けた冷
却ロール又はベルトを用いて冷却・搬送し、その溶融金
属表面に凝固シェルを形成させる。そして冷却ロール、
ベルトの回転または走行に伴って凝固シェルを成長させ
て、これを湯溜まり部から送り出すことによって鋳片を
鋳造する。
2. Description of the Related Art In a continuous casting method of thin cast slab, a molten metal injected into a pool is cooled and transported by using a cooling roll or a belt provided on a wall of the pool, and solidified on the surface of the molten metal. Allow the shell to form. And cooling rolls,
A slab is cast by growing a solidified shell with the rotation or running of the belt and sending it out of the pool.

【0003】このような連続鋳造方法において鋳片の形
状、特に厚みは溶融金属の温度に影響される。湯溜まり
部内部の溶融金属の温度は湯溜まり部の湯面レベルに相
関がある。従って、所要の厚みの鋳片を鋳造するために
は、この湯面レベルを前記相関に基づいて適宜のレベル
に保つ必要がある。ところが、湯溜まり部へ注入される
溶融金属の量はその供給源の給湯ノズルの開度と正確に
は対応しないという問題がある。従ってその給湯量を一
定に保つことは、容易ではない。
[0003] In such a continuous casting method, the shape, particularly the thickness, of the slab is affected by the temperature of the molten metal. The temperature of the molten metal inside the pool is correlated with the level of the molten metal in the pool. Therefore, in order to cast a slab having a required thickness, it is necessary to maintain the molten metal level at an appropriate level based on the correlation. However, there is a problem that the amount of the molten metal injected into the pool does not exactly correspond to the opening of the hot water supply nozzle of the supply source. Therefore, it is not easy to keep the hot water supply constant.

【0004】また湯溜まり部に溶融金属が入っていない
操業開始時には、前述の溶融金属の湯面レベルを湯溜ま
り部の底面から適宜のレベルまで引き上げる必要があ
り、これに要する時間は製品として不適合な鋳片が製造
される。従って、この時間が長いほど歩留りが悪くなる
ので、可及的速やかに湯面レベルを引き上げて、目標の
湯面レベルに収束させることが望ましい。
At the start of operation when molten metal does not enter the pool, it is necessary to raise the level of the molten metal from the bottom of the pool to an appropriate level. Slabs are produced. Therefore, since the yield becomes worse as this time is longer, it is desirable to raise the molten metal level as quickly as possible to converge to the target molten metal level.

【0005】仮に湯面レベルを速やかに引き上げるため
に、単純に給湯量を多くした場合、目標の湯面レベル付
近において制御速度が湯面レベルの上昇速度に追いつか
ず、湯面レベルがオーバーシュートを起こすことが予測
される。オーバーシュートが起きると湯面レベルが収束
するまでの時間が長引き、その結果製品として不適合な
鋳片がより多く製造されてしまう。従って、その給湯量
の調節には何らかの工夫が必要である。
If the amount of hot water is simply increased in order to quickly raise the level of the molten metal, the control speed cannot keep up with the rising speed of the molten metal level near the target molten metal level, and the molten metal level will overshoot. It is expected to happen. When overshoot occurs, the time until the surface level converges is prolonged, and as a result, more unsuitable slabs are produced as products. Therefore, some contrivance is required for adjusting the hot water supply amount.

【0006】そこでこの湯溜まり部の湯面レベルを目標
の湯面レベルまで速やかに引き上げ、しかも目標の湯面
レベルに到達した時点以降は湯面レベルを一定に保つた
めに前記給湯ノズルを制御する方法として、制御系の安
定性と応答性との優劣の配分をパラメータにより調節で
きるPID制御手法を用いるものが提案されている(特
開平6─304726号公報)。このパラメータは湯面
レベルの安定化及び湯面レベル引き上げ時間の短縮化の
兼ね合いに基づき設定される。
Accordingly, the hot water supply nozzle is controlled to quickly raise the level of the molten metal in the pool to a target level, and to keep the level constant after reaching the target level. As a method, there has been proposed a method using a PID control method capable of adjusting the distribution of the stability and responsiveness of a control system by using a parameter (Japanese Patent Laid-Open No. 6-304726). This parameter is set based on a balance between the stabilization of the level and the reduction of the time for raising the level.

【0007】[0007]

【発明が解決しようとする課題】従来のPID制御手法
は湯面レベルの安定化及び湯面レベル引き上げ時間の短
縮化の兼ね合いに基づきパラメータを設定するので、湯
面レベルの引き上げに要する時間の短縮化の余地がまだ
残されており、さらなる短縮化が望まれている。
In the conventional PID control method, parameters are set based on a balance between stabilization of the level of the molten metal and reduction of the time for raising the level of the molten metal. Therefore, the time required for raising the level of the molten metal is shortened. There is still room for conversion, and further reduction is desired.

【0008】本発明は斯かる事情に鑑みてなされたもの
であって、連続鋳造装置の操業開始時に湯溜まり部の溶
融金属の湯面レベルを目標のレベルまで速やかに引き上
げ、しかもその目標の湯面レベル付近におけるオーバー
シュートの発生を抑える、連続鋳造における湯面レベル
制御方法の提供を目的とする。
The present invention has been made in view of such circumstances, and when the continuous casting apparatus is started to operate, the molten metal level of the molten metal in the pool is quickly raised to a target level. An object of the present invention is to provide a method for controlling a molten metal level in continuous casting, which suppresses the occurrence of overshoot near the surface level.

【0009】[0009]

【課題を解決するための手段】本発明に係る湯面レベル
制御方法は、保持炉への溶融金属の注入に先立ち目標湯
面レベルより低い基準湯面レベルを定め、湯溜まり部の
湯面レベルを測定し、測定湯面レベルが前記基準湯面レ
ベルに達するまでは単位時間当たりの給湯量が単位時間
当たりの鋳造量より大きくなるように給湯ノズルの開度
を設定し、測定湯面レベルが前記基準湯面レベルに達し
た時点以降は単位時間当たりの給湯量が単位時間当たり
の鋳造量に近づく方向へ前記給湯ノズルの開度を調節
し、目標湯面レベルに対する測定湯面レベルの比率が所
定範囲に収まっている時間が所定の収束判定時間に達し
た時点以降は予め定めた制御方法により湯面レベルを目
標湯面レベルに保持すべく制御することを特徴とする。
According to the present invention, there is provided a method for controlling a level of a molten metal, wherein a reference level of the molten metal is lower than a target level of the molten metal before the molten metal is injected into the holding furnace. The hot water supply nozzle opening is set so that the hot water supply amount per unit time is larger than the casting amount per unit time until the measured hot water level reaches the reference hot water level, and the measured hot water level is After reaching the reference level, the opening degree of the hot water supply nozzle is adjusted so that the amount of hot water per unit time approaches the casting amount per unit time, and the ratio of the measured level to the target level is adjusted. After the time within the predetermined range reaches the predetermined convergence determination time, control is performed by a predetermined control method so as to maintain the metal level at the target level.

【0010】この連続鋳造における湯面レベルの制御方
法は、湯溜まり部の測定湯面レベルが予め定めた基準湯
面レベルに達するまでは湯面レベルを速やかに引き上げ
るために給湯ノズルの開度を単位時間当たりの給湯量が
単位時間当たりの鋳造量より大きくなるように設定し、
測定湯面レベルが前記基準湯面レベルに達した時点以降
は湯面レベルが予め定めた目標湯面レベルにオーバーシ
ュートを起こさずに収束するように給湯ノズルの開度を
調節して溶融金属を給湯し、目標湯面レベルに対する測
定湯面レベルの比率が所定範囲に収まっている時間が所
定の収束判定時間に達した時点以降は予め定めた制御方
法により湯面レベルを目標湯面レベルに保持すべく制御
することにより、湯面レベルを速やかに引き上げ、しか
も前記目標湯面レベルに速やかに収束させる。
The method for controlling the level of the molten metal in the continuous casting is to increase the opening of the hot water supply nozzle until the measured level of the molten metal in the pool reaches a predetermined reference level. Set the amount of hot water per unit time to be larger than the amount of casting per unit time,
After the measured level has reached the reference level, the molten metal is adjusted by adjusting the opening of the hot water supply nozzle so that the level falls to a predetermined target level without overshooting. After the time when the hot water is supplied and the ratio of the measured level to the target level falls within a predetermined range reaches a predetermined convergence determination time, the level is maintained at the target level by a predetermined control method. By controlling as much as possible, the molten metal level is quickly raised and, moreover, quickly converged to the target molten metal level.

【0011】以下に示す式(1)は単位時間当たりの給
湯量Qinを求める式である。
The following equation (1) is an equation for calculating the hot water supply amount Qin per unit time.

【0012】[0012]

【数1】 (Equation 1)

【0013】式(1)において、Astは給湯ノズルの開
口面積、Kq は溶融金属の流量係数、gは重力加速度、
H(t) は時刻tにおける保持炉内の湯面レベル計算値を
それぞれ表す。またSBは給湯ノズルの開口面積Astに
対する給湯ノズルの絞り込み量の比率、即ち給湯ノズル
開度を表す。
In equation (1), Ast is the opening area of the hot water supply nozzle, Kq is the flow coefficient of the molten metal, g is the gravitational acceleration,
H (t) represents the calculated value of the molten metal level in the holding furnace at time t. In addition, SB represents the ratio of the narrowing amount of the hot water supply nozzle to the opening area Ast of the hot water supply nozzle, that is, the opening degree of the hot water supply nozzle.

【0014】以下に湯面レベルが基準湯面レベルに達し
て以後、目標湯面レベルに達するまでの給湯ノズル開度
調節に係る調節量の計算式を示す。式(2)は給湯ノズ
ル開度SBを求める式である。
The following is a formula for calculating an adjustment amount for adjusting the degree of opening of the hot water supply nozzle from when the level reaches the reference level until the level reaches the target level. Equation (2) is an equation for calculating the hot water supply nozzle opening degree SB.

【0015】[0015]

【数2】 (Equation 2)

【0016】式(2)において、Vc は鋳造速度、Wは
鋳片幅、Gapは鋳片厚をそれぞれ表す。式(2)の両辺
を給湯ノズル開度SB自身で割ったときの右辺の分母は
単位時間当たりに湯溜まり部へ注入される溶融金属の
量、即ち給湯量Qinを表す。またこのときの右辺の分子
は単位時間当たりに湯溜まり部から送り出される鋳片の
量を表す。つまり、給湯ノズル開度SBは、湯溜まり部
へ注入される溶融金属の量と湯溜まり部から送り出され
る鋳片の量とを等しくする値に求まる。湯面レベルが基
準湯面レベルに達したことを検出したとき、給湯ノズル
開度SBを求め、この値に応じて給湯ノズルの開度を絞
り込む。
In the equation (2), Vc represents a casting speed, W represents a slab width, and Gap represents a slab thickness. The denominator on the right-hand side when both sides of equation (2) are divided by the hot-water supply nozzle opening SB itself represents the amount of molten metal injected into the hot-water pool per unit time, that is, the hot-water supply amount Qin. In addition, the numerator on the right side at this time represents the amount of slab sent out from the pool in a unit time. That is, the hot water supply nozzle opening SB is determined to a value that makes the amount of the molten metal injected into the pool and the amount of the slab sent from the pool equal. When it is detected that the molten metal level has reached the reference molten metal level, the hot water supply nozzle opening degree SB is obtained, and the opening degree of the hot water supply nozzle is narrowed according to this value.

【0017】式(3)は湯面レベル上昇速度偏差VLdを
求める式である。
Equation (3) is an equation for obtaining the level difference VLd of the molten metal level rising speed.

【0018】[0018]

【数3】 (Equation 3)

【0019】式(3)においてKv は適宜に定める給湯
レベル上昇速度係数である。Lsv1は目標湯面レベル、
Lpv(t) は時刻tにおける湯溜まり部の湯面レベル計測
値をそれぞれ表す。
In equation (3), Kv is a hot water supply level increasing speed coefficient appropriately determined. Lsv1 is the target surface level,
Lpv (t) represents the measured value of the level of the molten metal in the pool at time t.

【0020】右辺の第1項は目標湯面レベルLsv1 を時
刻t+1の湯面レベルと見なしたとき、時刻tから時刻
t+1までの間に湯面レベルを目標湯面レベルLsv1 ま
で単調に上昇させるときの湯面レベル上昇速度を表すこ
とになる。湯面レベルを速やかに引き上げ、しかも速や
かに収束させることが目標であることから、湯面レベル
計測値Lpv(t) と目標湯面レベルLsv1 との差が大きい
ほど値が大きくなり、しかも差が小さいほど値が小さく
なるように、この項を2乗する。さらにその増減の度合
いを給湯レベル上昇速度係数Kv により適宜に調節す
る。
The first term on the right-hand side monotonically raises the level of the molten metal to the target level Lsv1 from time t to time t + 1 when the target level Lsv1 is regarded as the level of the level at time t + 1. This indicates the speed of rise of the level of the molten metal at the time. Since the goal is to quickly raise and level the molten metal level quickly, the larger the difference between the measured molten metal level Lpv (t) and the target molten metal level Lsv1, the larger the value becomes. This term is squared so that the smaller the value, the smaller the value. Further, the degree of the increase or decrease is appropriately adjusted by the hot water supply level increasing speed coefficient Kv.

【0021】第1項から減算する第2項は時刻t−1か
ら時刻tまでの湯面レベルの上昇速度である。つまり湯
面レベル上昇速度偏差VLdは、湯面レベル上昇速度の変
更量を求めるための関数である。この湯面レベル上昇速
度偏差VLdは式(4)に示す給湯ノズル開度変更量ΔS
Tを求めるために使用される。
The second term subtracted from the first term is the rising speed of the molten metal level from time t-1 to time t. That is, the level rise speed deviation VLd is a function for determining the change amount of the level rise speed. This level difference VLd is the hot water supply nozzle opening change amount ΔS shown in equation (4).
Used to determine T.

【0022】[0022]

【数4】 (Equation 4)

【0023】式(4)においてAtdは目標湯面レベルL
sv1 における湯溜まり部の断面積を表す。つまり給湯ノ
ズル開度変更量ΔSTは、湯面レベル上昇速度偏差VLd
の値が大きいほど値が大きくなる関数であって、湯面レ
ベル上昇速度偏差VLdに基づく湯溜まり部内部の溶融金
属の目標増加量を満たすための給湯ノズルの変更量を求
める。一定時間間隔毎に給湯ノズル開度変更量ΔSTを
求め、この給湯ノズル開度変更量ΔST分だけ給湯ノズ
ルの開度を絞り込む。こうすることにより、湯面レベル
を速やかに引き上げ、しかも目標湯面レベルに速やかに
収束させることが出来る。
In equation (4), Atd is the target level L
Shows the cross-sectional area of the pool in sv1. That is, the hot water supply nozzle opening change amount ΔST is equal to the molten metal level rise speed deviation VLd.
Is a function whose value increases as the value increases, and determines a change amount of the hot water supply nozzle for satisfying the target increase amount of the molten metal in the pool in accordance with the level rise speed deviation VLd. The hot-water supply nozzle opening change amount ΔST is determined at regular time intervals, and the hot-water supply nozzle opening is narrowed by the hot-water supply nozzle opening change amount ΔST. By doing so, the level of the molten metal can be quickly raised and quickly converged to the target level.

【0024】式(5)は目標湯面レベルに対する湯溜ま
り部の湯面レベル計測値の比率γを求める式である。
Equation (5) is an equation for obtaining the ratio γ of the measured value of the molten metal level in the pool to the target molten metal level.

【0025】[0025]

【数5】 (Equation 5)

【0026】前述の如く給湯ノズルの開度を調節し、式
(5)に基づき目標湯面レベルLsv1 に対する湯面レベ
ル計測値Lpv(t) の比率γを求め、これが90〜110
%にある時間を計測する。その時間が予め定めた収束判
定時間を越えたとき、従来と同様の湯面レベル制御手順
に切り替えて湯面レベルを目標湯面レベルに保持する。
As described above, the opening degree of the hot water supply nozzle is adjusted, and the ratio γ of the measured level Lpv (t) to the target level Lsv1 is calculated based on equation (5).
Measure the time in%. When the time exceeds a predetermined convergence determination time, the control is switched to the same level control procedure as the conventional one, and the level is maintained at the target level.

【0027】[0027]

【発明の実施の形態】図1は本発明に係る薄肉鋳片連続
鋳造装置の構成を示すブロック図である。図において、
1は円筒容器状の保持炉である。保持炉1はこれに注入
された溶鋼2の温度を一定に保持する。保持炉1はその
底部に給湯ノズルを有し、該給湯ノズルの上部にはこれ
を塞いでその開度を調節する栓3が設けられている。栓
3はノズル制御部4により開度調節制御される。また保
持炉1には、それに注入された溶鋼2の重量を測定する
炉重測定部5を設けてある。
FIG. 1 is a block diagram showing the structure of a thin cast slab continuous casting apparatus according to the present invention. In the figure,
Reference numeral 1 denotes a cylindrical container-shaped holding furnace. The holding furnace 1 keeps the temperature of the molten steel 2 injected therein constant. The holding furnace 1 has a hot water supply nozzle at the bottom thereof, and a plug 3 for closing the hot water supply nozzle and adjusting the opening thereof is provided at an upper portion thereof. The opening degree of the stopper 3 is controlled by the nozzle controller 4. Further, the holding furnace 1 is provided with a furnace weight measuring unit 5 for measuring the weight of the molten steel 2 injected therein.

【0028】保持炉1の給湯ノズルの垂直下方にはその
給湯ノズルから流出する溶鋼2を受ける湯溜まり部6が
設けられている。湯溜まり部6はその壁面に上下一対の
冷却ロール7を有する。湯溜まり部6に溜められた溶鋼
2は冷却ロール7に挟み込まれ冷却されて、薄肉鋳片8
として湯溜まり部6の外部へ送り出される。
A hot water pool 6 for receiving molten steel 2 flowing out of the hot water supply nozzle is provided vertically below the hot water supply nozzle of the holding furnace 1. The pool 6 has a pair of upper and lower cooling rolls 7 on its wall. The molten steel 2 stored in the basin 6 is sandwiched between cooling rolls 7 and cooled, and the thin cast slab 8 is cooled.
Is sent out of the pool 6.

【0029】また、湯溜まり部6の底面から適宜の高さ
の位置には湯面レベルを測定するための渦流センサ9が
設けられている。渦流センサ9による測定結果は制御部
10に与えられ、制御部10は与えられた測定結果に基
づき、後述する処理手順に従って、ノズル制御部4へ開
度調節制御指令を与える。
An eddy current sensor 9 for measuring the level of the molten metal is provided at an appropriate height from the bottom of the pool 6. The measurement result of the eddy current sensor 9 is provided to the control unit 10, and the control unit 10 provides an opening adjustment control command to the nozzle control unit 4 based on the provided measurement result in accordance with a processing procedure described later.

【0030】図2は制御部10における処理手順を示す
フローチャートである。操業開始に先立ち、制御部10
と接続した図示しない入力手段から目標湯面レベルLsv
1 、基準湯面レベルLsv2 、給湯レベル上昇速度係数K
v 及び収束判定時間Ts を受け付けて制御部10の記憶
領域に格納しておく(S1)。また制御系の特性を表す
値である給湯ノズルの開口面積Ast、溶鋼の流量係数K
q 、鋳片幅W、鋳片厚Gap、鋳造速度Vc 及び湯溜まり
部6の目標湯面レベルLsv1 における断面積Atd並びに
溶鋼の比重及び保持炉の内周半径を受け付けて制御部1
0の記憶領域に格納しておく(S2)。
FIG. 2 is a flowchart showing a processing procedure in the control unit 10. Before starting operation, the control unit 10
From the input means (not shown) connected to the
1, reference level Lsv2, hot water supply level rise speed coefficient K
v and the convergence determination time Ts are received and stored in the storage area of the control unit 10 (S1). Also, the opening area Ast of the hot water supply nozzle, which is a value representing the characteristics of the control system, and the flow coefficient K of molten steel
q, the slab width W, the slab thickness Gap, the casting speed Vc, the cross-sectional area Atd of the pool 6 at the target molten metal level Lsv1, the specific gravity of the molten steel, and the inner radius of the holding furnace.
0 (S2).

【0031】前述したステップにおいて各設定値を設定
した後、連続鋳造ラインの稼働を指令する(S3)。即
ち、ノズル制御部4にノズル全開指令を与え、渦流セン
サ9による湯溜まり部6の湯面レベルの計測を開始し、
また炉重測定部5の測定値,溶鋼の比重及び保持炉の内
周半径に基づき保持炉内の湯面レベルH(t) の算出を開
始する。湯溜まり部6の湯面レベルが基準湯面レベルL
sv2 に達したとき(S4)、前述の式(2)に基づき給
湯ノズル開度SBを求め、給湯ノズルの開度を求めた値
に設定する(S5)。
After setting each set value in the above-described steps, the operation of the continuous casting line is commanded (S3). That is, a full-open nozzle command is given to the nozzle control unit 4, and the measurement of the level of the molten metal in the pool 6 by the eddy current sensor 9 is started.
Also, the calculation of the molten metal level H (t) in the holding furnace is started based on the measured value of the furnace weight measuring unit 5, the specific gravity of the molten steel, and the inner peripheral radius of the holding furnace. The level of the pool 6 is the reference level L
When sv2 has been reached (S4), the hot water supply nozzle opening SB is obtained based on the above-described equation (2), and the opening of the hot water supply nozzle is set to the obtained value (S5).

【0032】そして前述の式(3)に基づき湯面レベル
上昇速度偏差VLdを算出し(S6)、さらに前述の式
(4)に基づき給湯ノズル開度変更量ΔSTを求めて、
これに従い給湯ノズルを絞り込む(S7)。前述の式
(5)に基づき目標湯面レベルLsv1 に対する湯面レベ
ル計測値Lpv(t) の比率γを算出し(S8)、この比率
γが90〜110%の範囲にあるか否かを判別する(S
9)。比率γが90〜110%の範囲にある場合は湯面
レベルが収束しつつあるとみなして、時間をカウントす
る(S10)。
Then, based on the above equation (3), the molten metal level rise speed deviation VLd is calculated (S6). Further, based on the above equation (4), the hot water supply nozzle opening change amount ΔST is obtained.
In accordance with this, the hot water supply nozzle is narrowed down (S7). The ratio γ of the measured level Lpv (t) to the target level Lsv1 is calculated based on the above equation (5) (S8), and it is determined whether or not the ratio γ is in the range of 90 to 110%. Do (S
9). When the ratio γ is in the range of 90 to 110%, it is considered that the molten metal level is converging, and the time is counted (S10).

【0033】そしてカウント数が予め定めた収束判定時
間Ts に達したか否かを判別し(S11)、達したと判
定したとき公知の湯面レベル制御、例えばPID制御手
法による湯面レベル制御に切り替える(S12)。S9
において比率γが90〜110%の範囲にない場合は、
カウント数をリセットした後(S13)、前述のS6へ
処理を戻して以降の手順を繰り返す。またS11におい
てカウント数が収束判定時間Ts に達していないと判定
したときは、前述のS6へ処理を戻して以降の手順を繰
り返す。
Then, it is determined whether or not the count number has reached a predetermined convergence determination time Ts (S11). When it is determined that the count has reached the predetermined convergence determination time Ts, a known level control such as a PID control method is performed. Switching is performed (S12). S9
In the case where the ratio γ is not in the range of 90 to 110%,
After resetting the count number (S13), the process returns to S6, and the subsequent steps are repeated. If it is determined in step S11 that the count has not reached the convergence determination time Ts, the process returns to step S6, and the subsequent steps are repeated.

【0034】図3、図4はそれぞれ本発明及び従来技術
(特開平6─304726号公報)に係る湯面レベル制
御方法による制御結果を表すグラフである。図3及び図
4は同一装置構成において目標湯面レベルLsv1 を29
0(mm)に設定したときの湯面レベルの変化を表す。
FIGS. 3 and 4 are graphs showing the control results by the molten metal level control method according to the present invention and the prior art (Japanese Patent Laying-Open No. 6-304726), respectively. FIGS. 3 and 4 show that the target level Lsv1 is 29
This represents the change in the level of the molten metal when it is set to 0 (mm).

【0035】従来技術に係る湯面レベル制御方法による
制御結果を表す図4において湯面レベルの変化を表す曲
線は波打ちながら上昇している。そして目標湯面レベル
Lsv1 を越え、時刻Ta においてピークレベルに達した
あと、緩やかに目標湯面レベルLsv1 収束している。
In FIG. 4 showing the result of control by the level control method according to the prior art, the curve representing the change in level is rising while waving. Then, after exceeding the target level Lsv1 and reaching the peak level at the time Ta, the level gradually converges to the target level Lsv1.

【0036】本発明に係る湯面レベル制御方法による制
御結果を表す図3において、基準湯面レベルLsv2 を2
61(mm)に設定してあって、湯面レベルは時刻Tb1にこ
の基準湯面レベルLsv2 に達する。この時刻Tb1までの
勾配は、図4における時刻Ta までの勾配より急峻であ
る。時刻Tb1から湯面レベルの変化を表す勾配はそれま
でより緩やかになり、時刻Tb2において目標湯面レベル
Lsv1 に収束している。
In FIG. 3 showing a control result by the liquid level control method according to the present invention, the reference level Lsv2 is set to 2
It has been set to 61 (mm), and the molten metal level reaches this reference molten metal level Lsv2 at time Tb1. The slope up to time Tb1 is steeper than the slope up to time Ta in FIG. From time Tb1, the gradient representing the change in the molten metal level becomes gentler than before, and converges to the target molten metal level Lsv1 at time Tb2.

【0037】[0037]

【発明の効果】以上の如き本発明による場合は、基準湯
面レベルを定めておき、この基準湯面レベルに達するま
では給湯ノズルからその供給可能な最大量の溶鋼を湯溜
まり部に注入し、しかもその湯面レベルがオーバシュー
トを起こさないように制御することから湯面レベルを目
標湯面レベルに速く収束させることが出来る。従って、
連続鋳造装置の操業開始時における歩留りを良くするこ
とが出来る。
According to the present invention as described above, the reference level is determined, and until the reference level is reached, the maximum amount of molten steel that can be supplied from the hot water supply nozzle is injected into the pool. In addition, since the level is controlled so as not to cause overshoot, the level can be quickly converged to the target level. Therefore,
The yield at the start of the operation of the continuous casting device can be improved.

【図面の簡単な説明】[Brief description of the drawings]

【図1】本発明に係る薄肉連続鋳造装置の構成を示すブ
ロック図である。
FIG. 1 is a block diagram showing a configuration of a thin continuous casting apparatus according to the present invention.

【図2】制御部の処理手順を示すフローチャートであ
る。
FIG. 2 is a flowchart illustrating a processing procedure of a control unit.

【図3】本発明に係る溶鋼湯面レベル制御方法による制
御結果を表すグラフである。
FIG. 3 is a graph showing a control result by the molten steel level control method according to the present invention.

【図4】従来技術に係る溶鋼湯面レベル制御方法による
制御結果を表すグラフである。
FIG. 4 is a graph showing a control result by a molten steel level control method according to the related art.

【符号の説明】[Explanation of symbols]

3 栓 4 ノズル制御部 5 炉重測定部 6 湯溜まり部 7 冷却ロール 9 渦流センサ 10 制御部 Reference Signs List 3 stopper 4 nozzle control section 5 furnace weight measurement section 6 hot water pool section 7 cooling roll 9 eddy current sensor 10 control section

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】 給湯ノズルを設けてある保持炉と、鋳造
機構を設けた容器を具備する湯溜まり部とを有し、前記
保持炉に溶融金属を注入し、給湯ノズルから流出させた
溶融金属を前記湯溜まり部に受けて、湯溜まり部の湯面
レベルを目標湯面レベルに保持しつつ前記鋳造機構によ
って鋳片を連続的に鋳造する連続鋳造装置の湯面レベル
制御方法において、 保持炉への溶融金属の注入に先立ち目標湯面レベルより
低い基準湯面レベルを定め、湯溜まり部の湯面レベルを
測定し、測定湯面レベルが前記基準湯面レベルに達する
までは単位時間当たりの給湯量が単位時間当たりの鋳造
量より大きくなるように給湯ノズルの開度を設定し、測
定湯面レベルが前記基準湯面レベルに達した時点以降は
単位時間当たりの給湯量が単位時間当たりの鋳造量に近
づく方向へ前記給湯ノズルの開度を調節し、目標湯面レ
ベルに対する測定湯面レベルの比率が所定範囲に収まっ
ている時間が所定の収束判定時間に達した時点以降は予
め定めた制御方法により湯面レベルを目標湯面レベルに
保持すべく制御することを特徴とする湯面レベル制御方
法。
1. A holding furnace provided with a hot water supply nozzle, and a basin provided with a container provided with a casting mechanism, wherein molten metal is injected into the holding furnace and discharged from the hot water supply nozzle. In the continuous casting apparatus for continuously casting slabs by the casting mechanism while maintaining the molten metal level of the molten metal pool at the target molten metal level. Prior to the injection of the molten metal into the molten metal level, determine a reference level lower than the target level, measure the level of the pool, and measure the level per unit time until the measured level reaches the reference level. The opening degree of the hot water supply nozzle is set so that the hot water supply amount is larger than the casting amount per unit time, and after the measured hot water level reaches the reference hot water level, the hot water supply amount per unit time is per unit time. Casting amount The opening degree of the hot water supply nozzle is adjusted in the following direction, and after the time when the ratio of the measured level to the target level falls within a predetermined range reaches a predetermined convergence determination time, a predetermined control method is used. A method for controlling a level of a molten metal, comprising controlling the level of the molten metal to a target level.
JP02925297A 1997-02-13 1997-02-13 Level control method Expired - Fee Related JP3557829B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP02925297A JP3557829B2 (en) 1997-02-13 1997-02-13 Level control method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP02925297A JP3557829B2 (en) 1997-02-13 1997-02-13 Level control method

Publications (2)

Publication Number Publication Date
JPH10225751A true JPH10225751A (en) 1998-08-25
JP3557829B2 JP3557829B2 (en) 2004-08-25

Family

ID=12271090

Family Applications (1)

Application Number Title Priority Date Filing Date
JP02925297A Expired - Fee Related JP3557829B2 (en) 1997-02-13 1997-02-13 Level control method

Country Status (1)

Country Link
JP (1) JP3557829B2 (en)

Also Published As

Publication number Publication date
JP3557829B2 (en) 2004-08-25

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