JPH11279628A - Rh vacuum degassing method - Google Patents
Rh vacuum degassing methodInfo
- Publication number
- JPH11279628A JPH11279628A JP8435498A JP8435498A JPH11279628A JP H11279628 A JPH11279628 A JP H11279628A JP 8435498 A JP8435498 A JP 8435498A JP 8435498 A JP8435498 A JP 8435498A JP H11279628 A JPH11279628 A JP H11279628A
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- vacuum
- level
- ladle
- vacuum chamber
- 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
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】この発明は、溶鋼精錬法の一
つであるＲＨ真空脱ガス方法に関し、特に、溶鋼をサン
プリングし分析して例えば所定の成分値が目標範囲内に
収まっているか否かを検査する際に、取鍋内の溶鋼の状
態が変動することを防止でき、しかも検査完了後に極短
時間の内に操業を再開できるようにしたものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an RH vacuum degassing method, which is one of the methods for refining molten steel, and more particularly, to sampling and analyzing molten steel to determine whether a predetermined component value falls within a target range. When the inspection is performed, the state of the molten steel in the ladle can be prevented from fluctuating, and the operation can be resumed within an extremely short time after the inspection is completed.
【０００２】[0002]
【従来の技術】ＲＨ真空脱ガス方法を実施する場合、あ
る程度操業が行われた後に取鍋内からサンプリングした
溶鋼を分析して、溶鋼の所定の成分値が目標範囲内に収
まっているか否かを検査し、その検査の結果、目標範囲
内に収まっていることが確認できたらその時点で操業を
終了し、収まっていない場合には操業を再開し、例えば
検査時に把握した目標範囲からのズレ量に応じた時間だ
け還流を行ってから操業を終了するというのが一般的で
ある。2. Description of the Related Art When an RH vacuum degassing method is performed, molten steel sampled from a ladle after a certain degree of operation is analyzed to determine whether or not a predetermined component value of the molten steel is within a target range. Inspection, and if it is confirmed that it is within the target range, the operation is terminated at that point in time.If not, operation is resumed. Generally, the operation is terminated after refluxing for a time corresponding to the amount.
【０００３】しかし、サンプリングした溶鋼の検査には
数〜１０分程度の時間を要するために、検査を行ってい
る最中にも操業が進んでしまうと、操業を再開する時点
では検査結果とは異なった成分値になっている可能性が
高く、従って、検査時に把握した目標範囲からのズレ量
に応じた時間だけ還流を行っても、最終的な成分値が目
標範囲から外れてしまう可能性がある。そこで、検査中
の操業による成分値の変化を予測し、その予測分をも考
慮して操業再開後の還流時間を決定することが必要にな
るのであるが、予測精度にも限界があり、成分値の範囲
が極めて狭い要求に対しては十分に対処することができ
ない。[0003] However, the inspection of the sampled molten steel takes several minutes to about 10 minutes. Therefore, if the operation progresses during the inspection, the inspection result is not obtained when the operation is resumed. There is a high possibility that the component values are different. Therefore, even if the reflux is performed for the time corresponding to the deviation amount from the target range that was grasped during the inspection, the final component value may be out of the target range. There is. Therefore, it is necessary to predict the change in the component value due to the operation during the inspection and determine the reflux time after the restart of the operation in consideration of the predicted value. Requests with a very narrow range of values cannot be adequately addressed.
【０００４】このような問題点に着目した従来の技術と
して、特公昭５９−１９９６８号公報に開示されたもの
がある。即ち、その公報に開示されたＲＨ真空脱ガス操
業法にあっては、溶鋼の目標合金成分値の最終調整時期
に、溶鋼をサンプリングしてから合金材を添加するまで
の間、真空槽内の溶鋼レベルを真空槽底面以下に降下保
持した後、再び溶鋼レベルを定常操業レベルに復元する
とともに合金材添加を行うようになっていて、これによ
り、溶鋼の還流を分析時間中は停止して、その分析時間
中に溶鋼の成分値が大きく変化することを防止し、操業
再開時に的確な量の合金材の添加を可能として成分的中
率を向上することができる、というものであった。As a conventional technique focusing on such a problem, there is a technique disclosed in Japanese Patent Publication No. 59-19968. In other words, in the RH vacuum degassing operation method disclosed in that publication, at the time of final adjustment of the target alloy component value of the molten steel, from the time when the molten steel is sampled until the time when the alloy material is added, the inside of the vacuum chamber is After maintaining the molten steel level below the bottom of the vacuum tank, the molten steel level is restored to the normal operation level again and the alloy material is added, whereby the reflux of the molten steel is stopped during the analysis time, It was possible to prevent the component value of the molten steel from changing significantly during the analysis time, and to add an appropriate amount of alloy material when the operation was resumed, thereby improving the component ratio.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、上記公
報に開示された従来技術にあっては、真空槽内の溶鋼レ
ベルを真空槽底面以下に降下保持するために、具体的に
は、真空発生装置を停止させるとともに、真空槽内に大
気を導入してその真空槽内を一時復圧させるという方
策、若しくは、そのような復圧時に真空槽を上昇又は取
鍋を降下させるという方策をとっていたため、復圧させ
た分つまり真空度を積極的に低下させた分、操業再開時
に真空度を操業レベルに戻すのに時間を要してしまい、
それだけ全体の操業時間が長くなってしまうという問題
点がある。即ち、上記公報記載の技術にあっては、溶鋼
の還流ガス吹き込み管への逆流を防止することの必要性
から、還流ガスの吹き込みを停止して溶鋼の還流を一時
停止するという方策は採用できないということを前提と
しているため、真空槽の真空度を低下させるという方策
を採用していたのである。However, according to the prior art disclosed in the above-mentioned publication, in order to keep the molten steel level in the vacuum tank below the bottom of the vacuum tank, specifically, a vacuum generator is used. In order to take measures to temporarily stop the pressure inside the vacuum chamber by introducing air into the vacuum chamber, or to raise the vacuum chamber or lower the ladle during such pressure recovery However, it takes time to return the vacuum to the operating level when the operation is resumed,
There is a problem that the entire operation time becomes longer accordingly. That is, in the technology described in the above-mentioned publication, it is not possible to adopt a measure of stopping the flow of the reflux gas and temporarily stopping the reflux of the molten steel because of the necessity of preventing the backflow of the molten steel into the reflux gas injection pipe. Therefore, a measure of reducing the degree of vacuum in the vacuum chamber was adopted.
【０００６】また、分析時に真空槽内の溶鋼レベルを真
空槽底面以下に降下させると、それまで溶鋼に接してい
た浸漬管の内面が露出し、検査終了後の操業再開時に再
びその浸漬管内面が溶鋼と接することになるため、その
浸漬管内面に固定された耐火物が、通常の操業法による
場合よりも多くの回数熱負荷を繰り返し受けることにな
り、耐火物の損傷が進み易くその寿命が短くなるという
不具合もある。When the level of the molten steel in the vacuum chamber is lowered below the bottom of the vacuum chamber during the analysis, the inner surface of the immersion pipe that has been in contact with the molten steel is exposed, and when the operation is resumed after the inspection, the inner surface of the immersion pipe is again exposed. Will come into contact with the molten steel, so the refractory fixed to the inner surface of the immersion pipe will be repeatedly subjected to a thermal load more times than in the normal operation method, and the refractory will be easily damaged and its life will be extended. There is also a problem that is shortened.
【０００７】本発明は、このような従来の技術が有する
未解決の課題に着目してなされたものであって、溶鋼分
析中に取鍋内の溶鋼の状態が変動することを防止でき、
検査完了後に極短時間の内に操業を再開でき、しかも浸
漬管内面の耐火物の寿命が短くなることも防止できるＲ
Ｈ真空脱ガス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 unsolved problems of the prior art, and can prevent the state of molten steel in a ladle from changing during the analysis of molten steel.
The operation can be resumed within an extremely short time after the completion of the inspection, and the life of the refractory on the inner surface of the immersion pipe can be prevented from being shortened.
It is an object to provide an H vacuum degassing method.
【０００８】[0008]
【課題を解決するための手段】上記目的を達成するため
に、本発明は、真空槽下部の二本の浸漬管を取鍋内の溶
鋼中に挿入し、前記真空槽に接続された真空発生装置に
よりその真空槽内を大気から遮断するとともに排気を行
ってその真空槽内を真空状態として前記溶鋼をその真空
槽内に引き上げ、この状態で一方の前記浸漬管に還流ガ
スを吹き込んで前記溶鋼を還流させるＲＨ真空脱ガス方
法において、前記溶鋼をサンプリングし分析する際に
は、前記真空槽と大気との遮断状態を維持したまま前記
真空発生装置による前記排気を停止するとともに、その
排気の停止に伴う前記溶鋼レベルの低下に応じて、前記
取鍋内の前記溶鋼が前記浸漬管外面に設けられた冷却設
備に接しないようにその取鍋を降下させる一方、前記還
流ガスの吹き込み量を、前記還流が生じないレベル以下
で且つ前記溶鋼の還流ガス吹き込み管への逆流を防止で
きるレベル以上に減少させ、そして、前記溶鋼レベルが
前記真空槽の底面より下方となる前に前記分析を完了す
るようにした。In order to achieve the above-mentioned object, according to the present invention, two dip tubes at the lower part of a vacuum tank are inserted into molten steel in a ladle, and a vacuum generator connected to the vacuum tank is formed. The apparatus shuts off the vacuum chamber from the atmosphere and evacuates the vacuum chamber to evacuate the vacuum chamber, pulls up the molten steel into the vacuum chamber, and in this state, blows a reflux gas into one of the immersion pipes to blow the molten steel. In the RH vacuum degassing method of refluxing, when sampling and analyzing the molten steel, the evacuation by the vacuum generating device is stopped while the cutoff between the vacuum chamber and the atmosphere is maintained, and the evacuation is stopped. In response to the lowering of the molten steel level, the ladle is lowered so that the molten steel in the ladle does not come into contact with cooling equipment provided on the outer surface of the immersion pipe, while the amount of the reflux gas blown The analysis is completed before the molten steel level falls below the bottom of the vacuum tank, and is reduced to a level below the level at which the reflux does not occur and to a level at which the backflow of the molten steel to the reflux gas injection pipe can be prevented. I did it.
【０００９】ここで、真空槽と大気との遮断状態を維持
したまま真空発生装置による排気だけを停止すると、真
空槽内の真空度は、各部の避けられないリーク等によっ
て徐々に低下していく。すると、その真空度の低下に伴
って、真空槽内の溶鋼レベルも徐々に低下するが、その
溶鋼レベルが真空槽の底面以下になるまでに必要な時間
は、溶鋼をサンプリングし分析するのに通常必要な時間
に比べて十分に長いから、その溶鋼レベルが真空槽の底
面より高い位置にある間に溶鋼の分析を完了することは
比較的容易である。従って、溶鋼の分析中に浸漬管の内
面が露出することは避けられる。Here, when only the evacuation by the vacuum generator is stopped while maintaining the state of shutting off the vacuum chamber from the atmosphere, the degree of vacuum in the vacuum chamber gradually decreases due to unavoidable leaks of the respective parts. . Then, as the degree of vacuum decreases, the molten steel level in the vacuum chamber also gradually decreases.However, the time required for the molten steel level to fall below the bottom of the vacuum chamber is required to sample and analyze the molten steel. It is relatively easy to complete the analysis of the molten steel while its level is higher than the bottom of the vacuum chamber, usually long enough than required. Therefore, it is avoided that the inner surface of the dip tube is exposed during the analysis of the molten steel.
【００１０】そして、還流ガスの吹き込み量を溶鋼の還
流が生じないレベル以下に減少させるから、溶鋼の還流
は生じず、従って溶鋼の成分値が大きく変化することも
防止できる。しかも、還流ガスの吹き込み量は、溶鋼の
還流ガス吹き込み管への逆流を防止できるレベルを下回
る量には減少させないため、溶鋼が還流ガス吹き込み管
に逆流することは防止できる。なお、本発明者等が行っ
た実験によれば、還流ガスの吹き込み量を、還流に必要
な量の５０％以下にすれば、溶鋼の成分値を大きく変化
させるような還流は生じないことが判った。また、還流
ガス吹き込み管の直径にもよるが、ある程度の還流ガス
が吹き出していれば、その還流ガス吹き込み管への溶鋼
の逆流は防止できることも判った。因みに、還流ガス吹
き込み管の直径を１．５ｍｍ以下にすれば、還流ガスの
吹き込み量を零、つまり還流ガスの吹き込みを停止して
も、還流ガス吹き込み管への溶鋼の逆流は、その溶鋼の
表面張力によって不可能になることが判った。以上か
ら、還流ガス吹き込み管の直径等に基づき、還流ガスの
吹き込み量を適宜選定すれば、溶鋼の還流は生じず、し
かも還流ガス吹き込み管への溶鋼の逆流を防止すること
ができる。[0010] Since the amount of the reflux gas blown is reduced to a level at which the molten steel does not reflux, the reflux of the molten steel does not occur, and therefore, the component value of the molten steel can be prevented from largely changing. In addition, since the amount of the reflux gas blown is not reduced to a level below a level at which the molten steel can be prevented from flowing back into the reflux gas injection pipe, it is possible to prevent the molten steel from flowing back into the reflux gas injection pipe. According to an experiment conducted by the present inventors, if the amount of the reflux gas blown is set to 50% or less of the amount required for the reflux, the reflux that would greatly change the component value of the molten steel does not occur. understood. It has also been found that, depending on the diameter of the reflux gas injection pipe, if a certain amount of reflux gas is blown out, the backflow of molten steel into the reflux gas injection pipe can be prevented. By the way, if the diameter of the reflux gas injection pipe is set to 1.5 mm or less, the amount of the reflux gas blown is zero, that is, even if the injection of the reflux gas is stopped, the reverse flow of the molten steel into the reflux gas injection pipe causes the molten steel to flow backward. It has been found impossible by surface tension. As described above, if the amount of the reflux gas to be blown is appropriately selected based on the diameter and the like of the reflux gas blow-in tube, the molten steel does not reflux, and the backflow of the molten steel into the reflux gas blow-in tube can be prevented.
【００１１】[0011]
【発明の実施の形態】以下、この発明の実施の形態を図
面に基づいて説明する。図１乃至図３は本発明の一実施
の形態を示す図であって、図１は本発明を適用したＲＨ
真空脱ガス装置１の全体構成を示す図である。Embodiments of the present invention will be described below with reference to the drawings. 1 to 3 show an embodiment of the present invention. FIG. 1 shows an RH to which the present invention is applied.
It is a figure showing the whole vacuum degassing device 1 composition.
【００１２】即ち、このＲＨ真空脱ガス装置１は、真空
槽２と、取鍋３と、取鍋３の昇降装置４と、を備えてい
て、真空槽２の底面２Ａには、真下に延びる二本の浸漬
管５Ａ、５Ｂが設けられている。二本の浸漬管５Ａ、５
Ｂのそれぞれは、真空槽２の底面２Ａと一体になってい
る上部５ａと、この上部５ａにフランジ６を介して結合
された下部５ｂとで構成されていて、その下部５ｂの先
端部が取鍋３内の溶鋼中に挿入されるようになってい
る。フランジ６は、例えば特開平２−１２９３１４号公
報に開示されるようにその内部に冷却通路を有してい
て、その冷却通路内に冷却水を通過させることにより浸
漬管５Ａ、５Ｂに対する冷却作用が得られるようになっ
ている。つまり、本実施の形態では、このフランジ６が
冷却設備を兼ねている。That is, the RH vacuum degassing apparatus 1 includes a vacuum tank 2, a ladle 3, and a lifting device 4 for the ladle 3, and extends right below the bottom surface 2A of the vacuum tank 2. Two dip tubes 5A, 5B are provided. Two dip tubes 5A, 5
Each of B has an upper portion 5a integrated with the bottom surface 2A of the vacuum chamber 2 and a lower portion 5b connected to the upper portion 5a via a flange 6, and a tip of the lower portion 5b is taken. It is designed to be inserted into molten steel in the pan 3. The flange 6 has a cooling passage therein as disclosed in, for example, Japanese Patent Application Laid-Open No. 2-129314, and the cooling action on the immersion pipes 5A and 5B is achieved by passing cooling water through the cooling passage. You can get it. That is, in the present embodiment, the flange 6 also serves as a cooling facility.
【００１３】そして、一方の浸漬管５Ａのフランジ６よ
り若干下側の部位に、例えばアルゴンガス等の還流ガス
を供給可能な還流ガス供給装置７のガス供給配管７Ａが
接続されている。これより、ＲＨ真空脱ガス法に必要な
還流ガスを浸漬管５Ａ内に供給できるようになってい
る。ガス供給配管７Ａが、還流ガス吹き込み管に対応す
る。A gas supply pipe 7A of a reflux gas supply device 7 capable of supplying a reflux gas such as argon gas is connected to a portion of the one immersion pipe 5A slightly below the flange 6. Thus, the reflux gas required for the RH vacuum degassing method can be supplied into the immersion pipe 5A. The gas supply pipe 7A corresponds to a reflux gas blowing pipe.
【００１４】また、真空槽２には真空発生装置８が接続
されていて、ＲＨ真空脱ガス法を実施する際には、その
真空発生装置８によって、真空槽２内を大気から遮断す
るとともに、排気を行って所定の真空度が得られるよう
になっている。A vacuum generator 8 is connected to the vacuum chamber 2. When the RH vacuum degassing method is performed, the vacuum generator 2 shuts off the inside of the vacuum chamber 2 from the atmosphere. A predetermined degree of vacuum is obtained by performing evacuation.
【００１５】取鍋３は、鍋受台９に支持されていて、そ
の鍋受台９が、昇降装置４上に載置されるようになって
いる。昇降装置４は、床１０に掘られたピット１０Ａの
底に設置された昇降シリンダ４Ａと、上端部に鍋受台９
が載置され且つ昇降シリンダ４Ａによって昇降する昇降
フレーム４Ｂと、昇降フレーム４Ｂの上下動をガイドす
る複数のガイドローラ４Ｃと、を備えて構成されてい
る。The ladle 3 is supported by a pan support 9, and the pan support 9 is placed on an elevating device 4. The lifting device 4 includes a lifting cylinder 4A installed at the bottom of a pit 10A dug on the floor 10, and a pan support 9 at the upper end.
The lifting frame 4B, on which the lifting and lowering cylinder 4A is mounted and which is raised and lowered, and a plurality of guide rollers 4C for guiding the vertical movement of the lifting frame 4B, are provided.
【００１６】そして、本実施の形態では、昇降シリンダ
４Ａと、還流ガス供給装置７と、真空発生装置８とに対
して制御信号を発生しそれらの状態を制御可能な管理コ
ンピュータ１１が備えられていて、オペレータは、その
管理コンピュータ１１を操作することにより、ＲＨ真空
脱ガス装置１を稼働させるようになっている。In the present embodiment, a control computer 11 is provided which can generate control signals for the lifting cylinder 4A, the recirculating gas supply device 7, and the vacuum generating device 8 to control their states. The operator operates the RH vacuum degassing apparatus 1 by operating the management computer 11.
【００１７】本実施の形態にあっても、通常の操業時の
状況は公知の他のＲＨ真空脱ガス装置の場合と同様であ
って、図２（ａ）に示すように、昇降装置４によって取
鍋３を上昇させることにより両浸漬管５Ａ、５Ｂの先端
部を取鍋３内の溶鋼１２内に挿入させ、真空発生装置８
を作動させて真空槽２内を大気から遮断するとともに排
気して、真空槽２内を真空状態（例えば、０．３Ｔｏｒ
ｒ程度）とし、取鍋３内の溶鋼１２を真空槽２内にまで
引き上げる。そして、その状態で、供給配管７Ａを介し
て所定流量（例えば、１５００Ｎｌ／ｍｉｎ）の還流ガ
スを供給して、溶鋼１２を還流させる。Even in this embodiment, the state of normal operation is the same as that of the other known RH vacuum degassing apparatus, and as shown in FIG. By raising the ladle 3, the tips of both immersion tubes 5A, 5B are inserted into the molten steel 12 in the ladle 3, and the vacuum generator 8
Is operated to shut off and exhaust the inside of the vacuum chamber 2 from the atmosphere, and to evacuate the vacuum chamber 2 to a vacuum state (for example, 0.3 Torr).
r), and the molten steel 12 in the ladle 3 is pulled up into the vacuum chamber 2. Then, in this state, a reflux gas at a predetermined flow rate (for example, 1500 Nl / min) is supplied through the supply pipe 7A to reflux the molten steel 12.
【００１８】図２（ａ）の状態をある程度（数分程度）
継続させたら、溶鋼の所定の成分値が目標範囲内に収ま
っているか否かを検査するために、取鍋３内から溶鋼１
２をサンプリングして分析を行うのであるが、その際に
は、オペレータは、管理コンピュータ１１を操作して、
真空発生装置８による排気を停止する。但し、停止する
のは排気だけであり、真空槽２と大気との間の遮断状態
は維持する。The state of FIG. 2A is changed to some extent (about several minutes).
After the continuation, the molten steel 1 in the ladle 3 is inspected to check whether a predetermined component value of the molten steel is within the target range.
In this case, the operator operates the management computer 11 to sample
The evacuation by the vacuum generator 8 is stopped. However, only the exhaust is stopped, and the cutoff state between the vacuum chamber 2 and the atmosphere is maintained.
【００１９】すると、真空発生装置８の各部や途中の配
管の連結部等からのリークにより、真空槽２内の真空度
は徐々に低下していくため、真空発生装置８の性能にも
よるが、排気停止直後で１００〜２００Ｔｏｒｒ／ｍｉ
ｎ程度の速度、排気停止からしばらく経過した後では停
止直後よりもも低い速度で復圧していく。その結果、図
２（ｂ）に示すように、真空槽２内の溶鋼レベルは、徐
々に低下していく。Then, the degree of vacuum in the vacuum chamber 2 gradually decreases due to leaks from various parts of the vacuum generating device 8 and connecting portions of pipes on the way, and so on, depending on the performance of the vacuum generating device 8. 100 to 200 Torr / mi immediately after exhaust stop
After the evacuation is stopped for a while at a speed of about n, the pressure is restored at a lower speed than immediately after the stop. As a result, as shown in FIG. 2B, the molten steel level in the vacuum chamber 2 gradually decreases.
【００２０】排気停止と同時に、オペレータは、管理コ
ンピュータ１１を操作して、還流ガス発生装置７による
還流ガスの供給量を、操業時の半分程度に（例えば、８
００Ｎｌ／ｍｉｎ）減少させる。還流ガスを操業時の半
分程度に減少させても、溶鋼が、供給配管７Ａ内に逆流
することは防止できる。なお、供給配管７Ａの直径が
１．５ｍｍ以下の場合には、還流ガスの供給量を零にし
てもよい。At the same time as the evacuation is stopped, the operator operates the management computer 11 to reduce the supply amount of the recirculation gas by the recirculation gas generator 7 to about half of that during operation (for example, 8
(00 Nl / min). Even if the reflux gas is reduced to about half of that during operation, it is possible to prevent the molten steel from flowing back into the supply pipe 7A. When the diameter of the supply pipe 7A is 1.5 mm or less, the supply amount of the reflux gas may be set to zero.
【００２１】そして、図２（ｂ）に示すように、真空槽
２内の真空度が徐々にではあるが低下し、それに伴い真
空槽２内の溶鋼レベルが低下し、しかも還流ガスの流量
が減少すると、溶鋼の還流は実質的に停止し、溶鋼１２
の成分値が大きく変動する状況ではなくなる。よって、
この状態のうちの溶鋼をサンプリングし分析を終了すれ
ば、操業再開時に例えば適切量の合金材を添加する等の
的確な対処が行えるから、溶鋼１２の成分値を極めて狭
い目標範囲内に収めることも比較的容易に行えるのであ
る。Then, as shown in FIG. 2 (b), the degree of vacuum in the vacuum chamber 2 gradually decreases, and accordingly, the level of molten steel in the vacuum chamber 2 decreases, and the flow rate of the reflux gas decreases. When it decreases, the molten steel reflux substantially stops and the molten steel 12
Is no longer in a situation in which the component value of fluctuates greatly. Therefore,
If the molten steel in this state is sampled and the analysis is completed, appropriate measures such as adding an appropriate amount of alloy material can be taken when the operation is resumed, so that the component values of the molten steel 12 are kept within an extremely narrow target range. Can be performed relatively easily.
【００２２】なお、真空槽２内の真空度が徐々に低下す
ると、図２（ｃ）に示すように、真空槽２内の溶鋼レベ
ルもさらに低下するため、それに応じて取鍋３内の溶鋼
１２の液面１２Ａが上昇することになる。因みに、真空
槽２と取鍋３との底面積の比を１：３〜５程度とし、真
空槽２内の真空度の低下速度を２００Ｔｏｒｒ／ｍｉｎ
とすれば、取鍋３内の溶鋼１２の液面１２Ａの上昇速度
は、７５〜１２５ｍｍ／ｍｉｎとなる。When the degree of vacuum in the vacuum chamber 2 gradually decreases, the level of molten steel in the vacuum chamber 2 further decreases as shown in FIG. The liquid level 12A of 12 will rise. Incidentally, the ratio of the bottom area of the vacuum tank 2 to the ladle 3 is about 1: 3 to 5 and the rate of reduction of the degree of vacuum in the vacuum tank 2 is 200 Torr / min.
Then, the rising speed of the liquid level 12A of the molten steel 12 in the ladle 3 is 75 to 125 mm / min.
【００２３】そこで、オペレータは、その液面１２Ａの
上昇に応じ、管理コンピュータ１１を操作して昇降装置
４を作動させて、図２（ｃ）に示すように、取鍋３を徐
々に降下させ、もって溶鋼１２がフランジ６に接しない
ようにする。これにより、水冷式の冷却設備であるフラ
ンジ６に溶鋼１２が接するという好ましくない状況を回
避する。Then, the operator operates the elevating device 4 by operating the management computer 11 in accordance with the rise of the liquid level 12A, and gradually lowers the ladle 3 as shown in FIG. 2 (c). Thus, the molten steel 12 is prevented from contacting the flange 6. This avoids an undesirable situation in which the molten steel 12 comes into contact with the flange 6 that is a water-cooled cooling facility.
【００２４】さらに、真空槽２内の溶鋼レベルが低下す
ると、その溶鋼レベルが真空槽２の底面２Ａよりも低く
なる可能性があるが、そうならない内に、溶鋼の分析を
終了して必要な場合には操業を再開する。真空槽２内の
溶鋼レベルが底面２Ａより下方とならなければ、浸漬管
５Ａ、５Ｂの内面に固定された耐火物が受ける熱負荷の
回数が極端に増大することを防止でき、その耐火物の熱
損の進行を遅くできるのである。耐火物の熱損は、それ
が受ける熱負荷の回数に略比例することから、本実施の
形態であれば、上記公報に開示された従来のＲＨ真空脱
ガス操業法に比べて、浸漬管内の耐火物の寿命を２．５
倍程度延ばすことができる。Further, when the level of the molten steel in the vacuum chamber 2 is lowered, the level of the molten steel may be lower than the bottom surface 2A of the vacuum chamber 2. If so, restart the operation. If the molten steel level in the vacuum chamber 2 does not become lower than the bottom surface 2A, it is possible to prevent the number of thermal loads received by the refractory fixed to the inner surfaces of the immersion pipes 5A and 5B from being extremely increased, and to prevent the refractory from being rejected. This can slow down the progress of heat loss. Since the heat loss of the refractory is substantially proportional to the number of heat loads received by the refractory, according to the present embodiment, compared to the conventional RH vacuum degassing operation method disclosed in the above publication, the inside of the immersion pipe is reduced. 2.5 life of refractory
It can be extended about twice.
【００２５】そして、本実施の形態にあっては、溶鋼１
２の検査終了後に成分微調整のために操業を再開する場
合にも、真空層２内を完全に復圧している訳ではないの
で、それだけ短時間のうちの操業を再開することがで
き、上記公報に開示された従来のＲＨ真空脱ガス操業法
よりも全体の操業時間を短縮できるのである。In this embodiment, the molten steel 1
When the operation is restarted for fine adjustment of the components after the completion of the inspection in Step 2, since the pressure in the vacuum layer 2 is not completely restored, the operation can be restarted in a shorter time. The entire operation time can be shortened as compared with the conventional RH vacuum degassing operation method disclosed in the gazette.
【００２６】図３は、本実施の形態によるＲＨ真空脱ガ
ス実施時における、還流ガスの流量の変化（ａ）と、真
空槽２内の圧力の変化（ｂ）とを示す図である。即ち、
ＲＨ真空脱ガス装置１を作動させた時点を０分としてお
り、その時点でガス流量を１５００Ｎｌ／ｍｉｎとする
とともに、真空槽２内の圧力も減圧して数分のうちに７
６０Ｔｏｒｒから０．３Ｔｏｒｒ程度にする。そして、
１０分程度経過した時刻ｔ1 において、溶鋼１２をサン
プリングして分析を行うのであるが、かかる際に、ガス
流量を８００Ｎｌ／ｍｉｎに減少させるとともに、真空
発生装置８による排気のみを停止する。すると、図３
（ｂ）に破線で示すように、真空槽２内の圧力は徐々に
上昇する。ちなみに、この圧力上昇はリークによるもの
なので、排気を止めた直後は比較的急峻に上昇するが、
やや復圧した後はその圧力上昇速度も緩やかになる。ま
た、図３（ｂ）に一点鎖線で示すのは、上記公報に開示
された従来のＲＨ真空脱ガス操業法のように積極的に復
圧させた場合の圧力上昇の様子を示すものであって、本
実施の形態の場合に比較して明らかに急峻に圧力が上昇
することが判る。FIG. 3 is a diagram showing a change in the flow rate of the reflux gas (a) and a change in the pressure in the vacuum chamber 2 (b) when performing RH vacuum degassing according to the present embodiment. That is,
The time when the RH vacuum degassing apparatus 1 is operated is set to 0 minutes, at which time the gas flow rate is set to 1500 Nl / min, and the pressure in the vacuum chamber 2 is reduced to 7 minutes in several minutes.
The pressure is reduced from about 60 Torr to about 0.3 Torr. And
At time t 1 after about 10 minutes have elapsed, the molten steel 12 is sampled and analyzed. At this time, the gas flow rate is reduced to 800 Nl / min, and only the evacuation by the vacuum generator 8 is stopped. Then, FIG.
As shown by the dashed line in (b), the pressure in the vacuum chamber 2 gradually increases. By the way, since this pressure rise is due to leak, it rises relatively steeply immediately after stopping the exhaust,
After a slight pressure recovery, the rate of the pressure rise becomes slow. 3 (b) shows how the pressure rises when the pressure is positively restored as in the conventional RH vacuum degassing operation disclosed in the above publication. Thus, it can be seen that the pressure rises clearly and sharply as compared with the case of the present embodiment.
【００２７】そして、時刻ｔ2 において溶鋼１２の分析
が終了し、分析結果に応じて操業が再開されるのである
が、本実施の形態であれば、時刻ｔ2 においても真空槽
２内の圧力は極端に上昇している訳ではないので、直ぐ
さま操業を再開でき、比較的速い時間に処理を終了でき
るのである。これが一点鎖線で示すように圧力を復圧さ
せてしまうと、所定の真空度にするまでに時間を要して
しまい、処理の終了時間が後ろのずれてしまうのであ
る。Then, at time t 2 , the analysis of the molten steel 12 is completed, and the operation is restarted according to the analysis result. According to the present embodiment, the pressure in the vacuum chamber 2 is also maintained at time t 2 . Since is not rising extremely, the operation can be resumed immediately and the process can be completed in a relatively quick time. If the pressure is restored as indicated by the one-dot chain line, it takes a long time to reach a predetermined degree of vacuum, and the end time of the process is shifted backward.
【００２８】なお、上記実施の形態では、溶鋼１２の液
面１２Ａの上昇をオペレータが確認し、それに応じて管
理コンピュータ１１を操作することにより、溶鋼１２が
フランジ６に接しないように取鍋３を降下させるように
しているが、例えば、液面１２Ａの高さを検出するセン
サを設け、そのセンサ出力に応じて自動的に昇降装置４
を作動させて溶鋼１２がフランジ６に接しないように取
鍋３を降下させるようにしてもよい。In the above embodiment, the operator confirms that the liquid level 12A of the molten steel 12 has risen, and operates the management computer 11 accordingly. For example, a sensor for detecting the height of the liquid surface 12A is provided, and the elevating device 4 is automatically turned on in accordance with the sensor output.
May be operated to lower the ladle 3 so that the molten steel 12 does not contact the flange 6.
【００２９】また、上記実施の形態で示した各数値は、
いずれも一例であって、実際のＲＨ真空脱ガス装置１の
性能等に応じて適宜変わるものである。Each numerical value shown in the above embodiment is
These are merely examples, and may be appropriately changed according to the actual performance of the RH vacuum degassing apparatus 1 and the like.
【００３０】[0030]
【発明の効果】以上説明したように、本発明に係るＲＨ
真空脱ガス方法によれば、溶鋼をサンプリングし分析す
る際には、真空発生装置の排気のみをを停止するととも
に、その排気の停止に伴う溶鋼レベルの低下に応じて、
取鍋内の溶鋼が浸漬管外面に設けられた冷却設備に接し
ないようにその取鍋を降下させる一方、還流ガスの吹き
込み量を、還流が生じないレベル以下で且つ溶鋼の還流
ガス吹き込み管への逆流を防止できるレベル以上に減少
させ、そして、溶鋼レベルが真空槽の底面より下方とな
る前に分析を完了するようにしたため、比較的短時間の
うちの操業を再開できるから、処理終了までの時間を短
くできるし、溶鋼が還流ガス吹き出し管に逆流すること
も防止でき、浸漬管内の耐火物の耐久性が向上し、しか
も溶鋼が冷却設備に接することも回避できるという効果
がある。As described above, the RH according to the present invention is used.
According to the vacuum degassing method, when sampling and analyzing molten steel, only the evacuation of the vacuum generator is stopped, and in response to a decrease in the molten steel level due to the stoppage of the evacuation,
The ladle is lowered so that the molten steel in the ladle does not come into contact with the cooling equipment provided on the outer surface of the immersion pipe. Because the analysis was completed before the molten steel level became lower than the bottom of the vacuum chamber, the operation could be resumed in a relatively short time until the processing was completed. Can be shortened, the molten steel can be prevented from flowing back to the reflux gas blow-out pipe, the durability of the refractory inside the immersion pipe can be improved, and the molten steel can be prevented from coming into contact with the cooling equipment.
【図１】本発明の一実施の形態の全体構成図である。FIG. 1 is an overall configuration diagram of an embodiment of the present invention.
【図２】実施の形態の動作を説明する図である。FIG. 2 is a diagram illustrating the operation of the embodiment.
【図３】ガス流量及び槽内圧力の変化を示すグラフであ
る。FIG. 3 is a graph showing changes in gas flow rate and tank pressure.
１ ＲＨ真空脱ガス装置 ２ 真空槽 ３ 取鍋 ４ 昇降装置 ５Ａ、５Ｂ 浸漬管 ６ フランジ（冷却設備） ７ 還流ガス供給装置 ７ ガス供給配管（還流ガス吹き込み管） ８ 真空発生装置 １１ 管理コンピュータ DESCRIPTION OF SYMBOLS 1 RH vacuum degassing apparatus 2 Vacuum tank 3 Ladle 4 Elevating apparatus 5A, 5B Immersion pipe 6 Flange (cooling equipment) 7 Reflux gas supply apparatus 7 Gas supply pipe (Reflux gas blowing pipe) 8 Vacuum generation apparatus 11 Management computer
Claims (1)
鋼中に挿入し、前記真空槽に接続された真空発生装置に
よりその真空槽内を大気から遮断するとともに排気を行
ってその真空槽内を真空状態として前記溶鋼をその真空
槽内に引き上げ、この状態で一方の前記浸漬管に還流ガ
スを吹き込んで前記溶鋼を還流させるＲＨ真空脱ガス方
法において、 前記溶鋼をサンプリングし分析する際には、前記真空槽
と大気との遮断状態を維持したまま前記真空発生装置に
よる前記排気を停止するとともに、その排気の停止に伴
う前記溶鋼レベルの低下に応じて、前記取鍋内の前記溶
鋼が前記浸漬管外面に設けられた冷却設備に接しないよ
うにその取鍋を降下させる一方、前記還流ガスの吹き込
み量を、前記還流が生じないレベル以下で且つ前記溶鋼
の還流ガス吹き込み管への逆流を防止できるレベル以上
に減少させ、そして、前記溶鋼レベルが前記真空槽の底
面より下方となる前に前記分析を完了することを特徴と
するＲＨ真空脱ガス方法。1. Inserting two dip tubes in the lower part of a vacuum tank into molten steel in a ladle, and shutting off the inside of the vacuum tank from the atmosphere and evacuating by a vacuum generator connected to the vacuum tank. In an RH vacuum degassing method in which the molten steel is pulled up into the vacuum chamber with the vacuum inside the vacuum chamber and a reflux gas is blown into one of the immersion tubes to reflux the molten steel, the molten steel is sampled and analyzed. In doing so, while maintaining the state of the vacuum chamber and the atmosphere is shut off, the evacuation by the vacuum generator is stopped, and in response to a decrease in the molten steel level due to the stop of the evacuation, the inside of the ladle is The ladle is lowered so that the molten steel does not come into contact with the cooling equipment provided on the outer surface of the immersion pipe, and the amount of the reflux gas blown is set to a level at which the reflux does not occur and the molten steel is returned. It is reduced to more than the level that can prevent backflow into the gas blowing tube, and, RH vacuum degassing method, wherein the molten steel level has completed the analysis before it below the bottom surface of the vacuum chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08435498A JP3885346B2 (en) | 1998-03-30 | 1998-03-30 | Operation method of RH vacuum degassing equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP08435498A JP3885346B2 (en) | 1998-03-30 | 1998-03-30 | Operation method of RH vacuum degassing equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH11279628A true JPH11279628A (en) | 1999-10-12 |
| JP3885346B2 JP3885346B2 (en) | 2007-02-21 |
Family
ID=13828190
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP08435498A Expired - Fee Related JP3885346B2 (en) | 1998-03-30 | 1998-03-30 | Operation method of RH vacuum degassing equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3885346B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101188325B1 (en) | 2010-11-26 | 2012-10-09 | 주식회사 포스코 | Vacuum apparatus and vacuum degassing facility having the same |
| CN114408800A (en) * | 2022-03-01 | 2022-04-29 | 中冶南方工程技术有限公司 | Automatic jacking device for molten steel tank of RH vacuum refining furnace and control method |
-
1998
- 1998-03-30 JP JP08435498A patent/JP3885346B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101188325B1 (en) | 2010-11-26 | 2012-10-09 | 주식회사 포스코 | Vacuum apparatus and vacuum degassing facility having the same |
| CN114408800A (en) * | 2022-03-01 | 2022-04-29 | 中冶南方工程技术有限公司 | Automatic jacking device for molten steel tank of RH vacuum refining furnace and control method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3885346B2 (en) | 2007-02-21 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| KR100662895B1 (en) | Method for refining molten iron containing chromium | |
| US5225142A (en) | Method and apparatus for the automatic monitoring of operating safety and for controlling the progress of the process in a vacuum heat-treatment oven | |
| JPH11279628A (en) | Rh vacuum degassing method | |
| JP2009074161A (en) | Vacuum-degassing method | |
| US6880382B2 (en) | Leakage detecting method for use in oxidizing system of forming oxide layer | |
| JP3366449B2 (en) | Etching equipment | |
| JP2006130625A (en) | Vacuum chucking device and sucking pressure control method | |
| KR100196901B1 (en) | Method for measuring pressure of vacuum chamber | |
| JP4033123B2 (en) | Stave pipe breakage detection method and apparatus | |
| JP5223392B2 (en) | Exhaust start method in vacuum degassing apparatus | |
| KR20200134847A (en) | Apparatus for detecting breakage of bellows in blast furnace and control method thereof | |
| JP2009041553A (en) | Liquid leak measurement device for fuel injection valve | |
| US20240178023A1 (en) | Process detecting unit, substrate processing apparatus and substrate process monitoring method | |
| JPH02101110A (en) | Method for assuming carbon concentration in vacuum degassing refining | |
| JP2009130308A (en) | Surface processing apparatus | |
| KR102255353B1 (en) | Cooling apparatus and method for load lock chamber | |
| JPH03162511A (en) | Method for detecting water leakage in cooling box for blast furnace | |
| RU2101366C1 (en) | Method of rapidly estimating condition of lance when blowing through the smelt in ladle | |
| JP3293674B2 (en) | Control method of end point carbon concentration in RH degassing process | |
| JP6790229B2 (en) | Operation method of hydrogen handling equipment and hydrogen handling equipment | |
| CN117981059A (en) | Leak detection device, method for manufacturing semiconductor device, substrate processing method, and program | |
| KR20080093189A (en) | Gas leakage sensing system for gas supply device and method for gas leakage sensing | |
| JP4112991B2 (en) | Diagnosis method of vacuum exhaust equipment | |
| JPH04221787A (en) | Investigation method for branch pipe for liquid passage pipe | |
| JPH03247720A (en) | Method for measuring infiltering air quantity of rh vacuum degassing equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20041213 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20060704 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060901 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Effective date: 20061031 Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20061113 |
|
| R150 | Certificate of patent (=grant) or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20091201 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Year of fee payment: 4 Free format text: PAYMENT UNTIL: 20101201 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20101201 Year of fee payment: 4 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20111201 Year of fee payment: 5 |
|
| FPAY | Renewal fee payment (prs date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20121201 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |