JP3379296B2 - Atmosphere control method of heating furnace - Google Patents
Atmosphere control method of heating furnaceInfo
- Publication number
- JP3379296B2 JP3379296B2 JP20884195A JP20884195A JP3379296B2 JP 3379296 B2 JP3379296 B2 JP 3379296B2 JP 20884195 A JP20884195 A JP 20884195A JP 20884195 A JP20884195 A JP 20884195A JP 3379296 B2 JP3379296 B2 JP 3379296B2
- Authority
- JP
- Japan
- Prior art keywords
- furnace
- extraction
- steel material
- oxygen concentration
- heating furnace
- 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.)
- Expired - Fee Related
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Description
【発明の詳細な説明】
【０００１】
【発明の属する技術分野】本発明は、鋼材等の加熱炉の
雰囲気制御方法に関する。
【０００２】
【従来の技術】従来の鋼材加熱炉の抽出口近傍の断面図
の例を図４ａに示す。また、従来の鋼材加熱炉の抽出口
の正面図を図４ｂに示す。図中、１は加熱炉，２は鋼
材、３はスキッド、４はバーナ、５は抽出扉、６は鋼材
の搬出装置、６１は鋼材の搬出装置のアームをそれぞれ
示す。
【０００３】鋼材２は、図示されていない装入口より加
熱炉１の炉内に装入され、スキッド３上を右側に搬送さ
れながら、炉内に複数配置されたバーナ４により所定の
加熱温度に加熱されて、抽出口Ｘ近傍に到達する。抽出
口Ｘの開口部の形状は、図４ｂに示すように、鋼材２の
搬出が可能な長方形の開口と、炉内に挿入される鋼材搬
出装置６のアームの形状に合わせた切り欠き部分よりな
る。抽出口Ｘは、鋼材抽出時以外は抽出扉５により閉じ
られている。
【０００４】一般に、加熱炉内の雰囲気は、バーナに供
給する燃料と空気の流量比率を制御することにより、炉
内ガス中の酸素濃度が設定酸素濃度（例えば０．５％未
満）となるように調整されている。また、炉内ガスの排
出流量を調整することにより、炉内圧力を大気圧より１
０〜２０Ｐａ高く調節して、炉外から炉内へ空気が侵入
することを抑制している。これらの操作は、鋼材の加熱
中に、鋼材と酸素が反応して鋼材表面に酸化物、即ちス
ケールが多量に発生することを防止するためのものであ
る。
【０００５】加熱が完了した鋼材２は、鋼材搬出装置６
により抽出されるが、その時の操作は概ね以下の通りで
ある。まず、鋼材搬出装置６が鋼材抽出準備位置に移動
する。次いで、抽出扉５が上昇して、抽出口が開き、鋼
材搬出装置６が炉内から鋼材２を運び出す。最後に、抽
出扉５が下降して、抽出口が閉じる。
【０００６】
【発明が解決しようとする課題】図５は、抽出口付近の
ガス流れを示す断面図である。図において、矢印ａは炉
内ガスの流れ、矢印ｂは侵入空気の流れをそれぞれ示
す。その他の符号は図４に同じである。この図により、
鋼材２を炉外に抽出する際の抽出口付近のガス流れにつ
いて説明する。
【０００７】まず、抽出扉５を開けると、炉内圧が大気
圧より高いため炉内ガスが炉外に噴出する。この時、炉
内ガスの温度が高温であるため、ガスの噴出は抽出口の
上方に偏った流れ（図中、矢印ａ）となる。その後、炉
内ガスがある程度噴出すると、炉内外の圧力はバランス
する。しかし、炉内のスキッド３下部のガスも温度が高
いため、浮力により炉外に流出する。そのため、炉内の
ガスより低温で重い炉外空気が炉内に侵入し、炉内スキ
ッド下に流入する（図中、矢印ｂ）。流入した空気は、
スキッド下のバーナの火炎にて撹拌されて炉内に拡散す
る。
【０００８】図６は、従来の加熱炉における鋼材抽出時
の抽出口近傍における酸素濃度の時間変化を示す図であ
る。図において、横軸は時間、縦軸は酸素濃度をそれぞ
れ示す。炉内の酸素濃度は、抽出扉５を閉じている状態
では０．１％以下の低い値であるが、開けると同時に急
増し２％近くまで上昇する。その後、抽出扉５を閉じる
に従い酸素濃度は下降するが、閉じた後も直ちに０％近
くにならない。
【０００９】このように、抽出扉が開いている間は、酸
素濃度が設定値である０．５％を大幅に上回っており、
かつ、抽出扉を閉じてもしばらくの間は酸素濃度が高い
状態が継続している。炉内の酸素濃度の上昇により、鋼
材表面に多量のスケールが形成され製品品質の低下を招
くとともに、スケールの生成による製品の重量損失、即
ちスケールロスが発生し歩留り低下を招く。
【００１０】本発明は、このような、鋼材抽出時の炉内
酸素濃度上昇による製品品質低下の問題に鑑み、抽出扉
を開いた時に侵入する空気の炉内拡散を抑制して、製品
品質低下の問題を回避すべくなされたものである。
【００１１】
【００１２】
【００１３】
【００１４】
【００１５】【課題を解決するための手段】本発明は加熱炉の抽出側
の炉壁の内側でかつスキッドの下側に、炉幅方向に設置
された仕切壁と、前記仕切壁と抽出側の炉壁との間に設
置され、雰囲気ガスを加熱炉外に排気する排気管と、前
期仕切壁と前記抽出側の炉壁との間に設置された酸素濃
度計と、前記排気管内の流量を制御する流量制御弁とを
備えた加熱炉を用いて、抽出扉を開ける前に排気管の流
量制御弁を開き、酸素濃度計により雰囲気ガス中の酸素
濃度を測定しつつこの酸素濃度が設定値を上回らないよ
うに流量制御弁により排気管内の流量制御を行い、抽出
扉を閉じてから流量制御弁を閉じることを特徴とする加
熱炉の雰囲気制御方法である。
【００１６】この発明では、まず、抽出扉を開ける以前
に抽出口近傍のガスの加熱炉外への排気を開始している
ので、抽出扉を開けた時点で既に炉内から排気管に向か
う雰囲気ガスの流れが形成されている。従って、抽出扉
を開けた直後に大量に流入した空気は、このガス流れに
より排気管に運ばれる。ここで、排気管の流量、即ち排
気量が十分多ければ、排気管に向かう雰囲気ガスの流れ
（流量）も多くなる。従って、雰囲気ガス中の空気は希
釈され、雰囲気ガスの酸素濃度が低下する。
【００１７】次いで、雰囲気ガス中の酸素濃度を測定し
つつ、この酸素濃度が設定値を上回らないように排気管
内の流量制御を行うので、排気量を雰囲気ガスの酸素濃
度の低下に必要な程度とすることができる。従って、炉
内ガスの余分な排気による炉圧の過度な低下や、排気ガ
スの顕熱による熱損失を防止できる。
【００１８】最後に、抽出扉を閉じた後も制御弁を開い
ておくことにより、抽出扉を閉じた時点ではまだ炉内に
残存する空気、即ち酸素が引続き炉外に排出される。こ
のようにして、抽出口から流入した空気が速やかに炉外
に排出されるので、酸素濃度の上昇が抑制され、鋼材の
スケールロス等を低減できる。
【００１９】
【発明の実施の形態】図１は、本発明の実施の形態の一
例を示す断面図である。図１ａおよび図１ｂは、抽出口
の側面および正面から見た断面図である。図において、
１は加熱炉、２は鋼材、３はスキッド、４はバーナ、５
は抽出扉、６は鋼材の搬出装置、６１は鋼材の搬出装置
のアーム、７は仕切壁、８は排気管、８１は吸気口、８
２は８とは異なる形状の排気管、９は流量制御弁、１０
は酸素濃度計、Ｘは抽出口、Ｙは酸素濃度測定位置をそ
れぞれ示す。
【００２０】仕切壁７は、抽出口Ｘの炉内側でかつスキ
ッド３の下側に炉幅方向全長にわたって設置されてい
る。仕切壁７の高さは、空気の炉内への侵入を防ぐため
できるだけ高いことが望ましい。仕切壁７は、鋼材２の
移動の邪魔にならないようにすると、スキッド３とほぼ
同じ高さまで設けることが可能である。その場合、鋼材
搬出装置６のアームが当たらないよう切り欠き等を設け
ればよい。
【００２１】排気管８は加熱炉１の抽出側壁と仕切壁７
の間の加熱炉底部に設置されている。この排気管８は、
炉幅方向両端部で炉外に通ずる配管であり、炉内配管部
の下側に吸気口８１が多数開けられている。これは、鋼
材から剥離したスケールが吸気口を閉塞するのを防止す
るためである。なお、排気管８は、図では炉底から炉外
に導いているが、炉の側壁から炉外に導いても良い。
【００２２】また、排気管８は、排気管８２で示すよう
に炉の側壁から炉内に突き出す形で取付けても良い。但
しこの場合、その炉内挿入長さを長くしないと侵入空気
の排出能力が悪いので、炉幅が大きい場合には、適宜支
持具等を用いて先端部の変形（垂れ下がり）を防ぐこと
が望ましい。
【００２３】次に、鋼材２の抽出は、従来技術と同様、
抽出扉５を開けて鋼材の搬出装置６により鋼材２を搬出
する。その際、この発明では、抽出口Ｘ近傍のガスを排
気管８より吸引して加熱炉外に排気する。
【００２４】図２は、この時の抽出口周辺のガス流れを
示す断面図である。図において、矢印ａは炉内ガスの流
れ、矢印ｂは侵入空気の流れをそれぞれ示す。この発明
の加熱炉でも、抽出扉５を開けると、炉内ガスが矢印ａ
のように炉外に噴出し、炉外の空気が炉内に流入する。
ところが、流入した空気は仕切壁７により遮られ、炉壁
と仕切壁７の間に滞留する。この空気の混じった雰囲気
ガスを排気管８より吸引して加熱炉外の矢印ｃの方向に
排気する。このようにして、加熱炉１の抽出口近傍の侵
入空気の炉内への拡散が抑制できる。
【００２５】流入した空気の炉外への排気をより効率的
に行うためには、排気管の流量を制御するための流量制
御弁９と、雰囲気ガス中の酸素濃度を測定するための酸
素濃度計１０とを設置する。酸素濃度計１０で酸素濃度
を測定しながら、流量制御弁９により流量制御すること
により、炉圧の低下等を防ぐことができる。流量制御弁
９より先には図には示されていない排気装置が設置され
ている。
【００２６】この発明では、加熱炉外に排気した抽出口
近傍のガスを、加熱炉の予熱帯に戻すことも可能であ
る。このように排気した抽出口近傍のガスを加熱炉の予
熱帯に戻すことにより、ガスが持つ顕熱を再び炉内に戻
すことができるので、熱ロスを低減することができる。
【００２７】
【実施例】本発明を適用した加熱炉において、鋼材抽出
の操作は概ね以下の通りである。まず、鋼材の搬出装置
６を鋼材抽出準備位置に移動する。酸素濃度を計測しな
がら流量制御しつつ排気管８よりの排気を開始する。抽
出扉５を半開して鋼材の搬出装置のアームを炉内に挿入
する。鋼材の搬出装置６の先端が炉内で鋼材２を持ち上
げる。抽出扉５を全開して鋼材の搬出装置６が鋼材２を
炉外に抽出する。抽出扉５が下降して、抽出口が閉じ
る。排気管８よりの排気を停止する。
【００２８】この実施例では、排気するガス中の酸素濃
度を酸素濃度計１０により連続的に測定し、測定される
酸素濃度が、0.２％以下に収まるように、流量制御弁９
により流量制御しつつ、排気管８より雰囲気ガスを吸引
して加熱炉外に排気した。
【００２９】排気弁９は、この実施例では、抽出扉５を
開く時より約２秒早く開き、抽出扉５が閉じる時より約
２秒遅く閉じた。なお、この時間差は、排気流量と、炉
内仕切壁と抽出側壁との間の空間容積により変わりうる
ものであり、加熱炉毎に適切な時間差を求めておくこと
が望ましい。
【００３０】図３は、鋼材抽出時における抽出口近傍
（図１ａ中のＹで示す位置）の酸素濃度の変化を示す図
である。図において横軸は時間、縦軸は酸素濃度を示
す。図に示すように、抽出扉５が開く前の酸素濃度は
０. １％以下であった。抽出扉５が開いた直後は、酸素
濃度が瞬間的に０. ３％程度まで上昇した。しかし、直
ちに０. ２％未満に制御され、抽出扉５が閉じるまでこ
の状態が持続している。
【００３１】抽出扉５が閉じると直ちに０. １％以下に
制御されている。その後、抽出扉５が開く前の酸素濃度
にほぼ近い値まで低下している。このように、従来技術
における酸素濃度の推移（図６）と比較して、炉内酸素
濃度の上昇が大幅に抑制されている。
【００３２】
【発明の効果】本発明により、鋼材抽出時の炉内酸素濃
度上昇が抑制される。その結果、鋼材の表面酸化による
製品の品質低下が軽減される。さらに、スケールの生成
が抑制され、重量減少（スケールロス）が軽減されるこ
とから、製品歩留まりが向上する。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling the atmosphere of a heating furnace for steel or the like. 2. Description of the Related Art FIG. 4A shows an example of a cross-sectional view near an extraction port of a conventional steel heating furnace. FIG. 4B is a front view of an extraction port of a conventional steel heating furnace. In the figure, 1 is a heating furnace, 2 is a steel material, 3 is a skid, 4 is a burner, 5 is an extraction door, 6 is a steel material carry-out device, and 61 is a steel material carry-out device arm. [0003] The steel material 2 is charged into the furnace of the heating furnace 1 through a charging opening (not shown), and is conveyed to the right over the skid 3 while being heated to a predetermined heating temperature by a plurality of burners 4 arranged in the furnace. It is heated and reaches near the extraction port X. As shown in FIG. 4B, the shape of the opening of the extraction port X is, as shown in FIG. 4B, a rectangular opening through which the steel material 2 can be carried out, and a notch portion corresponding to the shape of the arm of the steel material carrying-out device 6 inserted into the furnace. Become. The extraction port X is closed by the extraction door 5 except at the time of extracting the steel material. In general, the atmosphere in a heating furnace is controlled such that the oxygen concentration in the furnace gas becomes a set oxygen concentration (for example, less than 0.5%) by controlling the flow rate ratio between fuel and air supplied to a burner. Has been adjusted. Further, by adjusting the discharge flow rate of the gas in the furnace, the pressure in the furnace is set to be lower than the atmospheric pressure by one.
The pressure is adjusted to be 0 to 20 Pa higher to prevent air from entering the furnace from outside the furnace. These operations are for preventing the steel material and oxygen from reacting during heating of the steel material to generate a large amount of oxides, that is, scale, on the steel material surface. [0005] The heated steel material 2 is supplied to a steel material unloading device 6.
The operation at that time is generally as follows. First, the steel material unloading device 6 moves to the steel material extraction preparation position. Next, the extraction door 5 is raised, the extraction port is opened, and the steel material carry-out device 6 carries the steel material 2 out of the furnace. Finally, the extraction door 5 is lowered, and the extraction port is closed. FIG. 5 is a sectional view showing a gas flow near the extraction port. In the figure, arrow a indicates the flow of gas in the furnace, and arrow b indicates the flow of intruding air. Other reference numerals are the same as in FIG. From this figure,
The gas flow near the extraction port when the steel material 2 is extracted outside the furnace will be described. [0007] First, when the extraction door 5 is opened, the furnace gas is blown out of the furnace because the furnace pressure is higher than the atmospheric pressure. At this time, since the temperature of the gas in the furnace is high, the jet of the gas becomes a flow (arrow a in the figure) biased above the extraction port. Thereafter, when the gas in the furnace is blown to some extent, the pressure inside and outside the furnace is balanced. However, the gas under the skid 3 in the furnace also has a high temperature and flows out of the furnace by buoyancy. Therefore, air outside the furnace that is heavier at a lower temperature than the gas in the furnace enters the furnace and flows under the furnace skid (arrow b in the figure). The incoming air is
It is agitated by the flame of the burner under the skid and diffuses into the furnace. FIG. 6 is a diagram showing a time change of the oxygen concentration in the vicinity of the extraction port at the time of extracting the steel material in the conventional heating furnace. In the figure, the horizontal axis represents time, and the vertical axis represents oxygen concentration. The oxygen concentration in the furnace is a low value of 0.1% or less when the extraction door 5 is closed, but increases rapidly to almost 2% as soon as the extraction door 5 is opened. Thereafter, as the extraction door 5 is closed, the oxygen concentration falls, but does not immediately become close to 0% even after closing. As described above, while the extraction door is open, the oxygen concentration greatly exceeds the set value of 0.5%,
In addition, even if the extraction door is closed, the state where the oxygen concentration is high continues for a while. Due to the increase in the oxygen concentration in the furnace, a large amount of scale is formed on the surface of the steel material, resulting in a decrease in product quality. In addition, a weight loss of the product due to the generation of scale, that is, a scale loss occurs, and the yield is reduced. The present invention has been made in view of such a problem that the product quality is deteriorated due to an increase in the oxygen concentration in the furnace at the time of extracting the steel material. This has been done to avoid the problem described above. SUMMARY OF THE INVENTION The present invention is directed to an extraction side of a heating furnace.
Installed in the furnace width direction inside the furnace wall and below the skid
Between the divided wall and the furnace wall on the extraction side.
An exhaust pipe that exhausts the atmosphere gas out of the heating furnace.
Oxygen concentration installed between the partition wall and the furnace wall on the extraction side.
Meter and a flow control valve for controlling the flow rate in the exhaust pipe.
Before opening the extraction door, use a heating furnace equipped with
Open the quantity control valve, and use the oxygen concentration meter to
This oxygen concentration does not exceed the set value while measuring the concentration
The flow rate in the exhaust pipe is controlled by the flow rate control valve to extract
Closing the door and then closing the flow control valve.
This is a method for controlling the atmosphere of a heating furnace. In the present invention, first, the gas near the extraction port is started to be exhausted to the outside of the heating furnace before the extraction door is opened. A gas flow is formed. Therefore, a large amount of air that has flowed in immediately after opening the extraction door is carried to the exhaust pipe by this gas flow. Here, if the flow rate of the exhaust pipe, that is, the exhaust amount is sufficiently large, the flow (flow rate) of the atmospheric gas toward the exhaust pipe also increases. Therefore, the air in the atmosphere gas is diluted, and the oxygen concentration of the atmosphere gas decreases. Next, while measuring the oxygen concentration in the atmosphere gas, the flow rate in the exhaust pipe is controlled so that this oxygen concentration does not exceed the set value. It can be. Therefore, it is possible to prevent the furnace pressure from excessively decreasing due to the excessive exhaust of the furnace gas and the heat loss due to the sensible heat of the exhaust gas. Finally, by opening the control valve even after closing the extraction door, the air still remaining in the furnace when the extraction door is closed, ie, oxygen, is continuously discharged out of the furnace. In this way, the air that has flowed in from the extraction port is quickly discharged out of the furnace, so that an increase in the oxygen concentration is suppressed, and scale loss and the like of the steel material can be reduced. FIG. 1 is a sectional view showing an example of an embodiment of the present invention. FIG. 1a and FIG. 1b are cross-sectional views as seen from the side and front of the extraction port. In the figure,
1 is a heating furnace, 2 is a steel material, 3 is a skid, 4 is a burner, 5
Is an extraction door, 6 is a steel material carry-out device, 61 is a steel material carry-out device arm, 7 is a partition wall, 8 is an exhaust pipe, 81 is an intake port, 8
2 is an exhaust pipe different in shape from 8, 9 is a flow control valve, 10
Indicates an oxygen concentration meter, X indicates an extraction port, and Y indicates an oxygen concentration measurement position. The partition wall 7 is installed inside the furnace of the extraction port X and below the skid 3 over the entire length in the furnace width direction. It is desirable that the height of the partition wall 7 be as high as possible to prevent air from entering the furnace. The partition wall 7 can be provided to almost the same height as the skid 3 so as not to hinder the movement of the steel material 2. In that case, a notch or the like may be provided so that the arm of the steel material carrying-out device 6 does not hit. The exhaust pipe 8 is connected to the extraction side wall and the partition wall 7 of the heating furnace 1.
Is installed at the bottom of the heating furnace. This exhaust pipe 8
The pipes communicate with the outside of the furnace at both ends in the furnace width direction, and a number of intake ports 81 are opened below the pipes in the furnace. This is to prevent the scale peeled from the steel material from blocking the intake port. Although the exhaust pipe 8 is guided from the furnace bottom to the outside of the furnace in the drawing, the exhaust pipe 8 may be guided to the outside of the furnace from the side wall of the furnace. The exhaust pipe 8 may be mounted so as to protrude into the furnace from the side wall of the furnace as shown by an exhaust pipe 82. However, in this case, the discharge capacity of the invading air is poor unless the insertion length in the furnace is long, so that when the furnace width is large, it is desirable to prevent deformation (hanging) of the tip portion by using a suitable support or the like as appropriate. . Next, extraction of the steel material 2 is performed in the same manner as in the prior art.
The extraction door 5 is opened and the steel material 2 is carried out by the steel material carry-out device 6. At this time, in the present invention, the gas near the extraction port X is sucked from the exhaust pipe 8 and exhausted outside the heating furnace. FIG. 2 is a sectional view showing the gas flow around the extraction port at this time. In the figure, arrow a indicates the flow of gas in the furnace, and arrow b indicates the flow of intruding air. In the heating furnace of the present invention, when the extraction door 5 is opened, the gas in the furnace is changed to the arrow a.
And the air outside the furnace flows into the furnace.
However, the inflowing air is blocked by the partition wall 7 and stays between the furnace wall and the partition wall 7. The atmosphere gas mixed with the air is sucked through the exhaust pipe 8 and exhausted in the direction of arrow c outside the heating furnace. In this way, diffusion of the intruding air near the extraction port of the heating furnace 1 into the furnace can be suppressed. In order to more efficiently discharge the inflowing air to the outside of the furnace, a flow control valve 9 for controlling the flow rate of the exhaust pipe and an oxygen concentration for measuring the oxygen concentration in the atmosphere gas are provided. 10 are installed. By controlling the flow rate with the flow rate control valve 9 while measuring the oxygen concentration with the oxygen concentration meter 10, it is possible to prevent a decrease in furnace pressure and the like. An exhaust device (not shown) is provided before the flow control valve 9. According to the present invention, the gas in the vicinity of the extraction port exhausted outside the heating furnace can be returned to the pre-tropical zone of the heating furnace. By returning the gas exhausted in the vicinity of the extraction port to the pre-tropical zone of the heating furnace, the sensible heat of the gas can be returned to the furnace, so that heat loss can be reduced. EXAMPLE In a heating furnace to which the present invention is applied, the operation of extracting a steel material is generally as follows. First, the steel material carry-out device 6 is moved to the steel material extraction preparation position. Exhaust from the exhaust pipe 8 is started while controlling the flow rate while measuring the oxygen concentration. The extraction door 5 is opened halfway, and the arm of the steel material carry-out device is inserted into the furnace. The tip of the steel material unloading device 6 lifts the steel material 2 in the furnace. The extraction door 5 is fully opened, and the steel material carry-out device 6 extracts the steel material 2 out of the furnace. The extraction door 5 is lowered, and the extraction port is closed. The exhaust from the exhaust pipe 8 is stopped. In this embodiment, the oxygen concentration in the exhaust gas is continuously measured by the oxygen concentration meter 10, and the flow control valve 9 is controlled so that the measured oxygen concentration falls below 0.2%.
While controlling the flow rate, atmospheric gas was sucked from the exhaust pipe 8 and exhausted to the outside of the heating furnace. In this embodiment, the exhaust valve 9 opens about 2 seconds earlier than when the extraction door 5 is opened, and closes about 2 seconds later than when the extraction door 5 closes. This time difference can vary depending on the exhaust gas flow rate and the volume of space between the in-furnace partition wall and the extraction side wall, and it is desirable to find an appropriate time difference for each heating furnace. FIG. 3 is a diagram showing a change in the oxygen concentration in the vicinity of the extraction port (the position indicated by Y in FIG. 1A) at the time of extracting the steel material. In the figure, the horizontal axis represents time, and the vertical axis represents oxygen concentration. As shown in the figure, the oxygen concentration before the extraction door 5 was opened was 0.1% or less. Immediately after the extraction door 5 was opened, the oxygen concentration instantaneously rose to about 0.3%. However, it is immediately controlled to be less than 0.2%, and this state is maintained until the extraction door 5 is closed. As soon as the extraction door 5 is closed, it is controlled to 0.1% or less. Thereafter, the oxygen concentration has decreased to a value substantially close to the oxygen concentration before the extraction door 5 was opened. As described above, the increase in the oxygen concentration in the furnace is significantly suppressed as compared with the transition of the oxygen concentration in the conventional technique (FIG. 6). According to the present invention, an increase in the oxygen concentration in the furnace at the time of extracting the steel material is suppressed. As a result, quality deterioration of the product due to surface oxidation of the steel material is reduced. Further, the production of scale is suppressed and the weight loss (scale loss) is reduced, so that the product yield is improved.
【図面の簡単な説明】
【図１】本発明の実施の形態の一例を示す断面図。
【図２】本発明におけるガス流れを示す断面図。
【図３】本発明における炉の抽出口近傍の酸素濃度変化
を示す図。
【図４】従来技術を示す断面図。
【図５】従来技術におけるガス流れを示す断面図。
【図６】従来技術における抽出口近傍の酸素濃度変化を
示す図。
【符号の説明】
１ 加熱炉
２ 鋼材
３ スキッド
５ 抽出扉
７ 仕切壁
８ 排気管
９ 流量制御弁
１０ 酸素濃度計BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a cross-sectional view illustrating an example of an embodiment of the present invention. FIG. 2 is a sectional view showing a gas flow in the present invention. FIG. 3 is a diagram showing a change in oxygen concentration near an extraction port of a furnace according to the present invention. FIG. 4 is a sectional view showing a conventional technique. FIG. 5 is a cross-sectional view showing a gas flow in the related art. FIG. 6 is a diagram showing a change in oxygen concentration in the vicinity of an extraction port in a conventional technique. [Description of Signs] 1 heating furnace 2 steel material 3 skid 5 extraction door 7 partition wall 8 exhaust pipe 9 flow control valve 10 oxygen concentration meter
───────────────────────────────────────────────────── フロントページの続き (58)調査した分野(Int.Cl.7，ＤＢ名) C21D 9/00 101 C21D 1/00 - 1/00 125 F27B 9/30 F27B 9/40 ──────────────────────────────────────────────────の Continued on the front page (58) Fields surveyed (Int. Cl. 7 , DB name) C21D 9/00 101 C21D 1/00-1/00 125 F27B 9/30 F27B 9/40
Claims (1)
ドの下側に、炉幅方向に設置された仕切壁と、前記仕切
壁と抽出側の炉壁との間に設置され、雰囲気ガスを加熱
炉外に排気する排気管と、前期仕切壁と前記抽出側の炉
壁との間に設置された酸素濃度計と、前記排気管内の流
量を制御する流量制御弁とを備えた加熱炉を用いて、抽
出扉を開ける前に排気管の流量制御弁を開き、酸素濃度
計により雰囲気ガス中の酸素濃度を測定しつつこの酸素
濃度が設定値を上回らないように流量制御弁により排気
管内の流量制御を行い、抽出扉を閉じてから流量制御弁
を閉じることを特徴とする加熱炉の雰囲気制御方法。 (57) [Claims 1] The inside of the furnace wall on the extraction side of the heating furnace and the
A partition wall installed in the furnace width direction below the
Installed between the wall and the furnace wall on the extraction side to heat the atmosphere gas
An exhaust pipe for exhausting outside of the furnace, the partition wall and the furnace on the extraction side
Oxygen meter installed between the wall and the flow in the exhaust pipe
Extraction using a heating furnace equipped with a flow control valve for controlling the flow rate.
Open the exhaust pipe flow control valve before opening the door, and
While measuring the oxygen concentration in the atmosphere gas with a
Exhaust by flow control valve so that the concentration does not exceed the set value
Control the flow rate in the pipe, close the extraction door, and then
A method for controlling the atmosphere of a heating furnace, comprising closing the heating chamber.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20884195A JP3379296B2 (en) | 1995-08-16 | 1995-08-16 | Atmosphere control method of heating furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20884195A JP3379296B2 (en) | 1995-08-16 | 1995-08-16 | Atmosphere control method of heating furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0953120A JPH0953120A (en) | 1997-02-25 |
| JP3379296B2 true JP3379296B2 (en) | 2003-02-24 |
Family
ID=16562995
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20884195A Expired - Fee Related JP3379296B2 (en) | 1995-08-16 | 1995-08-16 | Atmosphere control method of heating furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3379296B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107686881A (en) * | 2017-08-11 | 2018-02-13 | 重庆骏成机械配件有限公司 | Annealing system waste-heat recovery device |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100634776B1 (en) | 2001-01-17 | 2006-10-16 | 제이에프이 스틸 가부시키가이샤 | Heating furnace with regenerative burners and method of operating the heating furnace |
| KR101310650B1 (en) * | 2006-12-19 | 2013-09-25 | 재단법인 포항산업과학연구원 | Apparatus for Preventing Temperature of Furnace Dropping by Air Intake in Reheating Furnace |
-
1995
- 1995-08-16 JP JP20884195A patent/JP3379296B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107686881A (en) * | 2017-08-11 | 2018-02-13 | 重庆骏成机械配件有限公司 | Annealing system waste-heat recovery device |
| CN107686881B (en) * | 2017-08-11 | 2019-03-05 | 重庆骏成机械配件有限公司 | Annealing system waste-heat recovery device |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0953120A (en) | 1997-02-25 |
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