JPH06220530A - Method for controlling in-furnace atmosphere of vertical type induction heating furnace - Google Patents
Method for controlling in-furnace atmosphere of vertical type induction heating furnaceInfo
- Publication number
- JPH06220530A JPH06220530A JP50A JP1134993A JPH06220530A JP H06220530 A JPH06220530 A JP H06220530A JP 50 A JP50 A JP 50A JP 1134993 A JP1134993 A JP 1134993A JP H06220530 A JPH06220530 A JP H06220530A
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- atmosphere
- inert gas
- induction heating
- furnace body
- 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
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
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- Furnace Details (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、スラブ等の被加熱材を
誘導加熱する際における誘導加熱炉の炉内雰囲気を制御
する方法に関するもので、さらに詳述すれば、誘導加熱
炉への不活性ガスの吹き込みにより一定酸素濃度以下に
された炉内雰囲気を保持することを目的とした誘導加熱
炉の炉内雰囲気制御方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the furnace atmosphere of an induction heating furnace during induction heating of a material to be heated such as a slab. The present invention relates to a furnace atmosphere control method for an induction heating furnace, which is intended to maintain a furnace atmosphere in which a fixed oxygen concentration is maintained by blowing an active gas.
【０００２】[0002]
【従来の技術】スラブを下部装入式の竪型誘導加熱炉に
おいて高温に加熱する場合、炉内に不活性ガスを吹き込
む等して炉内雰囲気制御を行い、もってスケールの発生
を減少させる技術が従来から知られている。一般的な方
法としては、特開昭64−62411 号公報に開示された従来
技術があり、これは密封式の竪型誘導加熱炉によりスラ
ブを加熱するに際して、炉内に炉体下部から不活性ガス
を吹き込みながら炉内の雰囲気を炉体上部から放散さ
せ、炉内の酸素濃度を目標値にまで低下させたのち、炉
内雰囲気の炉体上部からの放散を遮断した状態で、炉内
に炉体上部から不活性ガスを吹き込み、炉内の酸素濃度
を制御する方法である。2. Description of the Related Art When heating a slab to a high temperature in a vertical-type induction heating furnace of a lower loading type, a technique for controlling the atmosphere in the furnace by blowing an inert gas into the furnace to reduce the generation of scale. Is conventionally known. As a general method, there is a conventional technique disclosed in Japanese Patent Application Laid-Open No. 64-62411, which is used for heating a slab by a sealed vertical induction heating furnace by inactivating the furnace from the bottom of the furnace body. After blowing the gas, the atmosphere in the furnace is diffused from the upper part of the furnace body, and the oxygen concentration in the furnace is reduced to the target value. This is a method of controlling the oxygen concentration in the furnace by blowing an inert gas from the upper part of the furnace body.
【０００３】また、前記の炉内の雰囲気を炉体外に放散
する速度を速くする方法として、特開昭61−34883 号公
報に開示されているように炉内ガスを吸引排出する装置
を設置して、吸引装置による炉内ガス吸引排出後に、不
活性ガスを前記炉内に供給することにより、炉内の酸素
濃度を予め設定された一定値以下に保持する方法もあ
る。Further, as a method for increasing the rate at which the atmosphere in the furnace is diffused to the outside of the furnace body, a device for sucking and discharging the gas in the furnace is installed as disclosed in JP-A-61-34883. Then, there is also a method of keeping the oxygen concentration in the furnace at a predetermined value or less by supplying an inert gas into the furnace after sucking and discharging the gas in the furnace by the suction device.
【０００４】[0004]
【発明が解決しようとする課題】ところで、一般にこの
種の密封式の竪型誘導加熱炉の密封を完全なものにする
ことは、極めて困難であり、例えば、誘導加熱の特性上
の問題として、被加熱材を加熱する加熱部の炉壁は、鋼
製構造ではなく、耐熱れんが、セラミックファイバ等の
断熱材により構成されるのが一般であり、通気性を完全
に遮断することは不可能である。By the way, in general, it is extremely difficult to complete the sealing of this type of vertical induction heating furnace. For example, as a characteristic problem of induction heating, The furnace wall of the heating part that heats the material to be heated is not made of steel, but is generally made of heat-resistant brick and a heat insulating material such as ceramic fiber, and it is impossible to completely block air permeability. is there.
【０００５】このため、従来技術のうち、後者について
は、加熱当初の炉内ガスの急速パージのため、吸引排出
する方法であるが、この方法では、吸引排出すること
で、炉内圧力が負圧となり、前記炉壁部あるいは、他の
シール部から外気を吹き込むことになり、炉内酸素濃度
を十分に低下させることができない。また、この種の竪
型誘導加熱炉では、炉内温度が炉外温度よりもかなり高
いレベルにあることから、炉内ガスがドラフト効果によ
り、炉内において上昇方向の流れとなり、炉内下部から
上部の高さ方向で炉内圧力に差が生ずる。このため、前
記の炉体の密封性を完全に確保することが困難であるこ
とと考え合わせると前記特開昭64−62441 号公報に示さ
れているように炉内下部の炉圧が正圧であることが、炉
内酸素濃度を低い状態に保つための必要条件となる。Therefore, of the conventional techniques, the latter is a method of sucking and discharging the gas for rapid purging of the gas in the furnace at the beginning of heating, but in this method, the pressure in the furnace is negative by sucking and discharging. As a result, the pressure is applied, and the outside air is blown from the furnace wall portion or another seal portion, so that the oxygen concentration in the furnace cannot be sufficiently reduced. Also, in this type of vertical induction heating furnace, the temperature inside the furnace is considerably higher than the temperature outside the furnace, so the gas inside the furnace becomes an upward flow in the furnace due to the draft effect, A difference occurs in the furnace pressure in the height direction of the upper part. Therefore, considering that it is difficult to completely secure the hermeticity of the furnace body, as shown in JP-A-64-62441, the furnace pressure in the lower part of the furnace is positive. Is a necessary condition for keeping the oxygen concentration in the furnace low.
【０００６】ところが、従来技術のうち前者の方法で
は、加熱当初における炉体内ガスのパージ後は、炉体上
部から不活性ガスを吹き込み制御することとなっている
が、この方法では、一定量の不活性ガスを投入した場合
炉体上部の炉圧向上には効果が大きいが炉体下部の炉圧
向上に対しては、あまり効果が得られない。さらに、炉
体上部から不活性ガスを吹き込んだ場合、炉体上部に装
入された被加熱材に低温の前記不活性ガスが接触するこ
とになり、加熱上好ましくないので不活性ガス量を制限
することが必要となり、炉内酸素濃度を低くするのを妨
げていた。However, in the former method of the prior art, after purging the gas in the furnace at the beginning of heating, the inert gas is controlled to be blown from the upper part of the furnace. When an inert gas is introduced, it is effective in improving the furnace pressure in the upper part of the furnace body, but not so effective in improving the furnace pressure in the lower part of the furnace body. Furthermore, when an inert gas is blown from the upper part of the furnace body, the low-temperature inert gas comes into contact with the material to be heated charged in the upper part of the furnace body, which is not preferable for heating, so the amount of the inert gas is limited. It was necessary to do so, and this hindered the reduction of the oxygen concentration in the furnace.
【０００７】本発明は、前記従来技術の問題点を解消
し、被加熱材を加熱することへの影響が少なく、適正な
不活性ガスの投入量により炉体内を低酸素濃度雰囲気に
保持することができる竪型誘導加熱炉の炉内雰囲気制御
方法を提供することを目的とするものである。The present invention solves the above-mentioned problems of the prior art, has less influence on heating of a material to be heated, and maintains a low oxygen concentration atmosphere in the furnace by an appropriate amount of inert gas. It is an object of the present invention to provide a method for controlling the atmosphere in a vertical induction heating furnace capable of achieving the above.
【０００８】[0008]
【課題を解決するための手段】前記目的を達成するため
の本発明は、竪型誘導加熱炉内に装入した被加熱材を誘
導加熱するに際して、炉体下部から炉内に不活性ガスを
吹き込みながら炉内雰囲気を炉体上部から放散させるこ
とにより炉内雰囲気の酸素濃度を目標値に到達するまで
低下させた後、前記炉内雰囲気の炉体上部からの放散を
遮断した状態として炉内雰囲気の酸素濃度を前記目標値
から上昇しないように炉体下部から炉内に吹き込む不活
性ガス量を制御することを特徴とする竪型誘導加熱炉の
炉内雰囲気制御方法である。The present invention for achieving the above-mentioned object is to provide an inert gas from the lower part of the furnace body into the furnace when the material to be heated charged in the vertical induction heating furnace is induction-heated. After the oxygen concentration in the furnace atmosphere is reduced to reach the target value by allowing the furnace atmosphere to diffuse from the upper part of the furnace while blowing, the furnace atmosphere with the release of the furnace atmosphere from the upper part of the furnace body is cut off. A furnace atmosphere control method for a vertical induction heating furnace, comprising controlling the amount of inert gas blown into the furnace from the lower part of the furnace body so that the oxygen concentration of the atmosphere does not rise from the target value.
【０００９】前記本発明において、炉下部から炉内に吹
き込む不活性ガス量を制御して炉体内下部の炉内雰囲気
圧力を正圧に保持することが好ましく、さらには、炉体
下部から炉内に吹き込む不活性ガス量を制御して、炉体
内下部で測定される炉内雰囲気の酸素濃度が目標値から
上昇しないようにするのが好適である。In the present invention, it is preferable to control the amount of the inert gas blown into the furnace from the lower part of the furnace to maintain the atmospheric pressure in the furnace at the lower part of the furnace body at a positive pressure. It is preferable to control the amount of inert gas blown into the furnace so that the oxygen concentration in the furnace atmosphere measured in the lower part of the furnace body does not rise from the target value.
【００１０】[0010]
【作用】本発明によれば、スラブ等の被加熱材を竪型の
誘導加熱炉により加熱する際における炉体内の雰囲気制
御において、まず不活性ガスを炉体の下部から吹き込み
ながら炉内雰囲気を炉体上部から外部に放散させること
により、迅速かつ効率的に、炉内雰囲気を置換し炉内の
酸素濃度を目標値まで低下到達させる。According to the present invention, in controlling the atmosphere in the furnace body when heating a material to be heated such as a slab in a vertical induction heating furnace, first, the atmosphere in the furnace is controlled while blowing an inert gas from the lower part of the furnace body. By diffusing from the upper part of the furnace body to the outside, the atmosphere in the furnace is replaced quickly and efficiently to reduce the oxygen concentration in the furnace to the target value.
【００１１】炉体の下部から不活性ガスを吹き込むの
で、炉内ガスのドラフト作用により低炉圧となり易い炉
体下部の圧力保持に効果的である。また、吹き込まれた
炉内ガスは、ドラフト作用により、炉体内を上昇中に加
熱された状態で被加熱材と接触するため、従来の方法で
問題となっていた、不活性ガス吹き込み部付近の被加熱
材の局部的な温度低下を防止することができる。さらに
炉体下部から不活性ガスを吹き込むようにしたので炉体
下部の圧力を効果的に上げることが可能となり炉体下部
から外気を吸い込むのを防止するために必要となる不活
性ガスの量を少なくすることができる。Since the inert gas is blown from the lower part of the furnace body, it is effective for maintaining the pressure in the lower part of the furnace body, which tends to have a low furnace pressure due to the draft action of the gas in the furnace. Further, the blown gas in the furnace comes into contact with the material to be heated while being heated in the furnace body by the draft action, so that there is a problem in the conventional method, that is, in the vicinity of the inert gas blowing part. It is possible to prevent a local temperature drop of the material to be heated. Furthermore, since the inert gas is blown from the lower part of the furnace body, the pressure in the lower part of the furnace body can be effectively increased, and the amount of the inert gas required to prevent the intake of the outside air from the lower part of the furnace body can be reduced. Can be reduced.
【００１２】[0012]
【実施例】図１は、本発明方法を実施すべく構成した竪
型誘導加熱炉の構成例を示すもので、炉体２は、通常、
断熱レンガ、セラミックファイバ等を用いて有頂筒形状
に成形され、この炉体２の側壁外周面に複数（図示実施
例の場合、４組）のブロックに分割された加熱コイル３
を組付けている。EXAMPLE FIG. 1 shows an example of the construction of a vertical induction heating furnace configured to carry out the method of the present invention.
A heating coil 3 formed in a topped cylindrical shape using a heat insulating brick, a ceramic fiber, etc., and divided into a plurality of (4 sets in the case of the illustrated embodiment) blocks on the outer peripheral surface of the side wall of the furnace body 2.
Is assembled.
【００１３】スラブ等の被加熱材１は、炉床４に載荷保
持された状態で、昇降ビーム５を昇降装置（図示せず）
を用いて昇降することにより、炉内への装入、抽出が行
われる。この昇降ビーム５の廻りには、加熱中に発生し
た溶融スケール（ノロ）が落下してくるのを回収するた
めのノロ受け６が設置されている。また下方に開放され
た炉体２の下端開口部は支持架台８に支持されており、
この支持架台８の下部に設けられた炉体下部シール７内
にノロ受け６の上端部を挿入したり離脱することにより
開閉されるようになっている。A material 1 to be heated such as a slab is loaded and held on a hearth 4 and a lifting device (not shown) for lifting a lifting beam 5 is provided.
By ascending and descending using, the charging and extraction into the furnace is performed. Around the up-and-down beam 5, there is provided a slag receiver 6 for collecting the falling of the molten scale (slag) generated during heating. Further, the lower end opening of the furnace body 2 opened downward is supported by the support frame 8,
It is adapted to be opened and closed by inserting or removing the upper end of the slag receiver 6 into the lower furnace body seal 7 provided in the lower part of the support frame 8.
【００１４】ノロ受け６の下部には、炉体２内に窒素ガ
ス等の不活性ガス吹き込み口11が形成されていると共
に、炉体２内の炉下部の炉内雰囲気酸素濃度を測定する
炉下部酸素濃度測定口12および炉内雰囲気圧力を測定す
る炉下部圧力測定口13が設けてある。さらに炉体２の炉
頂部にも、同様に炉上部酸素濃度測定口14および炉上部
圧力測定口15が設けてある。また炉頂部の天井には放散
口16が開口形成され、この放散口16はシリンダ10の伸縮
作用により放散用蓋９により開閉制御される。An inert gas inlet 11 such as nitrogen gas is formed in the furnace body 2 in the lower part of the slag receiver 6, and a furnace for measuring the oxygen concentration in the furnace atmosphere at the lower part of the furnace body 2 is measured. A lower oxygen concentration measurement port 12 and a furnace lower pressure measurement port 13 for measuring the atmospheric pressure in the furnace are provided. Further, the furnace top oxygen concentration measuring port 14 and the furnace upper pressure measuring port 15 are also provided at the furnace top of the furnace body 2. Further, a diffusion port 16 is formed on the ceiling of the furnace top, and the diffusion port 16 is controlled to open and close by the diffusion lid 9 by the expansion and contraction of the cylinder 10.
【００１５】竪型誘導加熱炉を用いて被加熱材１を誘導
加熱するに際し、まず不活性ガス吹き込み口11から大量
の不活性ガスを炉体２内に吹き込み、炉下部酸素濃度測
定口12および炉上部酸素測定口14から採取した雰囲気ガ
スを酸素濃度計で測定し、この測定値が目標値に達する
まで大量の不活性ガスの吹き込みを継続する。そして炉
内雰囲気の酸素濃度が目標値に達するまで低下したらシ
リンダ10を作動して放散用蓋９により放散口16を閉状態
として炉体２の内部を密閉状態に保持する。When inductively heating the material to be heated 1 using a vertical induction heating furnace, first, a large amount of inert gas is blown into the furnace body 2 through the inert gas blowing port 11, and the furnace lower oxygen concentration measuring port 12 and The atmospheric gas sampled from the furnace upper oxygen measuring port 14 is measured by an oxygen concentration meter, and a large amount of inert gas is continuously blown in until the measured value reaches a target value. When the oxygen concentration in the furnace atmosphere reaches the target value, the cylinder 10 is operated and the diffusion lid 9 closes the diffusion port 16 to keep the inside of the furnace body 2 sealed.
【００１６】しかしながら、この種の炉体２における密
閉状態の保持は困難であり、必ずある程度の内部雰囲気
の放逸は避けられないので、この放逸する不活性ガスを
補い、かつ外気が炉体１内に侵入しないように不活性ガ
ス吹き込み口11から必要量の不活性ガスを炉体２内に吹
き込み続ける。この際の吹き込み量の設定としては、炉
体２内への外気の侵入を防止することが目的であるの
で、炉体２内の圧力が負圧にならないように制御するの
が好ましい。However, it is difficult to maintain a closed state in the furnace body 2 of this kind, and it is inevitable that the internal atmosphere is released to some extent. A necessary amount of inert gas is continuously blown into the furnace body 2 through the inert gas blowing port 11 so as not to enter the inside of the furnace 1. Since the purpose of setting the blowing amount at this time is to prevent outside air from entering the furnace body 2, it is preferable to control so that the pressure in the furnace body 2 does not become a negative pressure.
【００１７】すなわち、炉内ガスが放逸することによ
り、炉内圧力が負圧となり、外気が引き込まれるのを防
止するため、炉下部圧力測定口13および炉上部圧力測定
口15にそれぞれ設けた圧力計により炉体２内の圧力を監
視し、圧力が負圧とならないように炉体２内に不活性ガ
スを供給する。この場合、負圧の発生は、炉体２下部に
生じるので、炉下部圧力測定口13で測定した圧力を常に
正圧に保持するように不活性ガスの炉体２への供給量を
制御する。That is, in order to prevent the pressure inside the furnace from becoming negative due to the release of the gas inside the furnace, and the outside air is prevented from being drawn in, the lower pressure measuring port 13 and the upper pressure measuring port 15 of the furnace are provided respectively. The pressure inside the furnace body 2 is monitored by a pressure gauge, and an inert gas is supplied into the furnace body 2 so that the pressure does not become negative. In this case, since the negative pressure is generated in the lower part of the furnace body 2, the supply amount of the inert gas to the furnace body 2 is controlled so that the pressure measured at the furnace lower part pressure measuring port 13 is always kept positive. .
【００１８】また、炉体２下部の負圧発生を防止するの
が目的であるので、不活性ガスの吹き込みは、炉体下部
から行い、これによって炉体２下部圧力への応答性効果
を高め、炉内ガスのドラフト作用により、炉内雰囲気ガ
スを押し上げる方向に作用させることにより、被加熱材
料１へ、低温の不活性ガスが接触することを防止する。Since the purpose is to prevent the generation of negative pressure in the lower part of the furnace body 2, the inert gas is blown from the lower part of the furnace body 2 to enhance the responsiveness effect to the lower pressure of the furnace body 2. By the draft action of the furnace gas, the atmosphere gas in the furnace is pushed up to prevent the low temperature inert gas from coming into contact with the material 1 to be heated.
【００１９】なお、炉体２内への不活性ガスの吹き込み
制御のもう一つの方法としては、炉体２内の酸素濃度を
常時測定し、この酸素濃度が目標値を保つように不活性
ガスの炉体内への供給を制御することもできる。この場
合は、酸素濃度の測定は、下部、上部酸素濃度測定口1
2、14を用いて行う。次に本発明方法の操業結果につい
て説明する。被加熱材であるスラブを通常加熱炉で平均
温度1200℃まで加熱した後、図１の誘導加熱炉で窒素ガ
スによるパージを行いながら加熱を行った。スラブ装入
後、放散口16を開状態として、不活性ガス吹き込み口11
（８ヶ所）から1500Nm3 ／Hrでパージしたところ約２分
で目標の500ppmまで炉体２内の酸素ガス濃度が下がっ
た。その後、放散口16を閉状態として、上部の炉体２内
の酸素濃度が目標値500ppmを保持するように流量制御し
ながら窒素ガスを炉体２内に吹き込んだところ、図２に
示すように、炉体内の酸素濃度 500±30ppm 、窒素ガス
流量 400±50Nm3 ／Hrで安定に保持できた。As another method of controlling the blowing of the inert gas into the furnace body 2, the oxygen concentration in the furnace body 2 is constantly measured, and the inert gas is maintained so that the oxygen concentration maintains a target value. It is also possible to control the supply of the gas into the furnace body. In this case, the oxygen concentration is measured in the lower and upper oxygen concentration measurement ports 1
Use steps 2 and 14. Next, the operation results of the method of the present invention will be described. After heating the slab as the material to be heated to an average temperature of 1200 ° C. in a normal heating furnace, heating was performed in the induction heating furnace of FIG. 1 while purging with nitrogen gas. After charging the slab, the discharge port 16 is opened and the inert gas blowing port 11
Purging from (8 places) with 1500 Nm 3 / Hr reduced the oxygen gas concentration in the furnace body 2 to the target of 500 ppm in about 2 minutes. After that, the diffusion port 16 was closed and nitrogen gas was blown into the furnace body 2 while controlling the flow rate so that the oxygen concentration in the upper furnace body 2 was kept at the target value of 500 ppm, as shown in FIG. The oxygen concentration in the furnace was 500 ± 30ppm and the nitrogen gas flow rate was 400 ± 50Nm 3 / Hr.
【００２０】また、炉体２内での高さ方向の炉圧分布を
調査した結果を図３に示した。図３の（ａ）、（ｂ）と
も、吹き込み窒素ガス流量 400Nm3 ／Hrのデータである
が、（ａ）は従来方法として、窒素ガスを上部から吹き
込んだ場合であり、（ｂ）は本発明の方法として、窒素
ガスを下部から吹き込んだ場合であり、（ａ）では、炉
頂部の圧力は高いが炉底部で若干の負圧になっている
が、（ｂ）では、炉底部も正圧となっているため、炉体
内への外気の侵入が防止できている。このように本発明
では、炉下部から不活性ガスを吹き込むため、侵入大気
を完全に遮断することができるので、炉内雰囲気の酸素
濃度を目標値に安定して保持することができる。FIG. 3 shows the result of investigation of the furnace pressure distribution in the furnace body 2 in the height direction. Both (a) and (b) of FIG. 3 show the data of the flow rate of blown nitrogen gas of 400 Nm 3 / Hr. (A) shows the case where nitrogen gas is blown from above as the conventional method, and (b) shows the As a method of the invention, a case where nitrogen gas was blown from the lower side was used. In (a), the pressure at the top of the furnace was high, but there was a slight negative pressure at the bottom of the furnace, but in (b), the bottom of the furnace was also positive. Because of the pressure, it is possible to prevent outside air from entering the furnace. As described above, in the present invention, since the inert gas is blown from the lower part of the furnace, the invading atmosphere can be completely shut off, so that the oxygen concentration in the furnace atmosphere can be stably maintained at the target value.
【００２１】[0021]
【発明の効果】以上の説明から明らかなごとく、本発明
は、炉体内雰囲気の不活性ガスとの置換を、炉体内雰囲
気の自然対流現象と不活性ガスの炉体内への吹き込み動
作とを利用して達成することにより、極めて速やかに達
成できる。またこのように速やかに達成できた炉体内の
酸素濃度雰囲気を不活性ガスの炉体内への継続した吹き
込み供給により目標値以下に安定した状態で維持するの
で、スケールロスの大幅な削減と炉体損傷の効果的な低
減を得ることができ、また得られた炉体内雰囲気の酸素
ガス濃度の抑制制御は、単に不活性ガスの炉体内への吹
き込みにより達成するので、その操作が簡単で自動化も
容易である等多くの優れた効果を発揮するものである。
さらに、吹き込まれた不活性ガスが低温の状態で被加熱
材に接することを防げるため吹き込み部付近における材
料の局部的な冷却が発生しないという効果もある。As is apparent from the above description, the present invention utilizes the natural convection phenomenon of the atmosphere in the furnace and the operation of blowing the inert gas into the furnace to replace the atmosphere in the furnace with the inert gas. Can be achieved very quickly. In addition, since the oxygen concentration atmosphere in the furnace body that was quickly achieved in this way can be maintained in a stable state below the target value by continuous blowing of inert gas into the furnace body, a significant reduction in scale loss and The effective reduction of damage can be obtained, and the suppression control of the oxygen gas concentration of the obtained atmosphere in the furnace is achieved simply by blowing the inert gas into the furnace, so that the operation is simple and can be automated. It exhibits many excellent effects such as being easy.
Further, since the blown-in inert gas can be prevented from coming into contact with the material to be heated at a low temperature, there is an effect that local cooling of the material does not occur near the blown-in portion.
【図１】本発明の実施例の構成を示す断面図である。FIG. 1 is a sectional view showing a configuration of an exemplary embodiment of the present invention.
【図２】本発明のＮ2 ガス吹き込み量と炉内Ｏ2 濃度の
推移を示す線図である。FIG. 2 is a diagram showing changes in the N 2 gas blowing amount and the O 2 concentration in the furnace according to the present invention.
【図３】炉底部からの高さと炉圧分布との関係を本発明
と従来とについて比較して示す線図である。FIG. 3 is a diagram showing the relationship between the height from the bottom of the furnace and the distribution of furnace pressure in comparison between the present invention and the prior art.
１ 材料 ２ 炉体 ３ 誘導加熱コイル ４ 炉床 ５ 昇降ビーム ６ ノロ受け ７ 炉体下部シール ８ 炉体架台 ９ 放散用蓋 10 シリンダ 11 不活性ガス吹き込み口 12 炉下部酸素濃度測定口 13 炉下部圧力測定口 14 炉上部酸素濃度測定口 15 炉上部圧力測定口 16 放散口 1 Material 2 Furnace Body 3 Induction Heating Coil 4 Hearth 5 Lifting Beam 6 Noro Receiver 7 Furnace Bottom Seal 8 Furnace Stand 9 Emission Lid 10 Cylinder 11 Inert Gas Blowout 12 Furnace Lower Oxygen Concentration Measurement 13 Furnace Bottom Pressure Measuring port 14 Upper furnace oxygen concentration measuring port 15 Upper furnace pressure measuring port 16 Discharge port
Claims (3)
誘導加熱するに際して、炉体下部から炉内に不活性ガス
を吹き込みながら炉内雰囲気を炉体上部から放散させる
ことにより炉内雰囲気の酸素濃度を目標値に到達するま
で低下させた後、前記炉内雰囲気の炉体上部からの放散
を遮断した状態として炉内雰囲気の酸素濃度を前記目標
値から上昇しないように炉体下部から炉内に吹き込む不
活性ガス量を制御することを特徴とする竪型誘導加熱炉
の炉内雰囲気制御方法。1. When the material to be heated loaded in a vertical induction heating furnace is induction-heated, the furnace atmosphere is diffused from the upper part of the furnace while blowing an inert gas into the furnace from the lower part of the furnace. After lowering the oxygen concentration of the internal atmosphere to reach a target value, the oxygen concentration of the furnace atmosphere is prevented from rising from the target value while the emission of the furnace atmosphere from the upper part of the furnace body is blocked. A furnace atmosphere control method for a vertical induction heating furnace, comprising controlling the amount of inert gas blown into the furnace from below.
量を制御して炉体内下部の炉内雰囲気圧力を正圧に保持
することを特徴とする請求項１記載の竪型誘導加熱炉の
炉内雰囲気制御方法。2. The vertical induction heating furnace according to claim 1, wherein the amount of inert gas blown into the furnace from the lower part of the furnace body is controlled to maintain the atmospheric pressure in the furnace lower part of the furnace body at a positive pressure. Atmosphere control method in.
量を制御して、炉体内下部で測定される炉内雰囲気の酸
素濃度が目標値から上昇しないようにすることを特徴と
する請求項１または請求項２記載の竪型誘導炉の炉内雰
囲気制御方法。3. The amount of inert gas blown into the furnace from the lower part of the furnace body is controlled so that the oxygen concentration of the atmosphere in the furnace measured in the lower part of the furnace body does not rise from a target value. The method for controlling the atmosphere in a vertical induction furnace according to claim 1 or 2.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5011349A JP2723161B2 (en) | 1993-01-27 | 1993-01-27 | Atmosphere control method for vertical induction heating furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5011349A JP2723161B2 (en) | 1993-01-27 | 1993-01-27 | Atmosphere control method for vertical induction heating furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06220530A true JPH06220530A (en) | 1994-08-09 |
| JP2723161B2 JP2723161B2 (en) | 1998-03-09 |
Family
ID=11775568
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5011349A Expired - Fee Related JP2723161B2 (en) | 1993-01-27 | 1993-01-27 | Atmosphere control method for vertical induction heating furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2723161B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009019262A (en) * | 2007-06-14 | 2009-01-29 | Toyota Central R&D Labs Inc | Device for preparing molten metal, method of preparing molten metal, device for degassing or removing non-metallic inclusions of molten metal, method of manufacturing molten metal, and method for degassing or removing non-metallic inclusions of molten metal |
| CN107955877A (en) * | 2017-11-27 | 2018-04-24 | 山东钢铁股份有限公司 | The control method of ultra low oxygen content in roller hearth heat-treated furnace |
| JP2019166532A (en) * | 2018-03-22 | 2019-10-03 | 日本電気株式会社 | Manufacturing apparatus and method |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6462411A (en) * | 1987-08-31 | 1989-03-08 | Kawasaki Steel Co | Method for controlling atmosphere in induction heating furnace |
| JPH01136928A (en) * | 1987-11-20 | 1989-05-30 | Kawasaki Steel Corp | Vertical type induction heater |
| JPH0211717A (en) * | 1988-06-30 | 1990-01-16 | Kawasaki Steel Corp | Method and device for controlling temperature in induction heating apparatus |
-
1993
- 1993-01-27 JP JP5011349A patent/JP2723161B2/en not_active Expired - Fee Related
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6462411A (en) * | 1987-08-31 | 1989-03-08 | Kawasaki Steel Co | Method for controlling atmosphere in induction heating furnace |
| JPH01136928A (en) * | 1987-11-20 | 1989-05-30 | Kawasaki Steel Corp | Vertical type induction heater |
| JPH0211717A (en) * | 1988-06-30 | 1990-01-16 | Kawasaki Steel Corp | Method and device for controlling temperature in induction heating apparatus |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009019262A (en) * | 2007-06-14 | 2009-01-29 | Toyota Central R&D Labs Inc | Device for preparing molten metal, method of preparing molten metal, device for degassing or removing non-metallic inclusions of molten metal, method of manufacturing molten metal, and method for degassing or removing non-metallic inclusions of molten metal |
| JP2012067389A (en) * | 2007-06-14 | 2012-04-05 | Toyota Central R&D Labs Inc | Device for preparing molten metal, method of preparing molten metal, device for degassing or removing non-metallic inclusion of molten metal, method of manufacturing molten metal, and method for degassing or removing non-metallic inclusion of molten metal |
| CN107955877A (en) * | 2017-11-27 | 2018-04-24 | 山东钢铁股份有限公司 | The control method of ultra low oxygen content in roller hearth heat-treated furnace |
| CN107955877B (en) * | 2017-11-27 | 2020-01-03 | 山东钢铁股份有限公司 | Control method for ultra-low oxygen content in roller hearth heat treatment furnace |
| JP2019166532A (en) * | 2018-03-22 | 2019-10-03 | 日本電気株式会社 | Manufacturing apparatus and method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP2723161B2 (en) | 1998-03-09 |
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