JPH11172326A - Method for controlling atmosphere in furnace and device therefor - Google Patents
Method for controlling atmosphere in furnace and device thereforInfo
- Publication number
- JPH11172326A JPH11172326A JP33567197A JP33567197A JPH11172326A JP H11172326 A JPH11172326 A JP H11172326A JP 33567197 A JP33567197 A JP 33567197A JP 33567197 A JP33567197 A JP 33567197A JP H11172326 A JPH11172326 A JP H11172326A
- Authority
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- Japan
- Prior art keywords
- furnace
- extraction port
- detected
- extraction
- furnace pressure
- 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.)
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- Control Of Heat Treatment Processes (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、被加熱材の加熱や
熱処理を行う開閉扉付きの炉の炉内雰囲気の制御方法及
びそのための装置に係り、特に、炉内に侵入する外気に
よる炉内酸素濃度の上昇を迅速に防止できる炉内雰囲気
制御方法とその装置に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and a device for controlling the atmosphere in a furnace having an opening / closing door for heating and heat-treating a material to be heated, and more particularly, to a method for controlling the atmosphere inside a furnace by outside air entering the furnace. The present invention relates to a furnace atmosphere control method and apparatus capable of promptly preventing an increase in oxygen concentration.
【０００２】[0002]
【従来の技術】例えば、炉内で燃料を燃焼させて被加熱
材の鋼片を加熱する鋼片加熱炉にあっては、その鋼片を
所定の温度まで加熱する際に、炉内の酸素により鋼片表
面が酸化されてスケールが生成する。酸化スケールが存
在すると後工程で製品の品質が損なわれるので不純物と
して除去しなければならず、歩留損失（スケールロス）
となる。このスケールロスを最小限に留めるには、加熱
時の炉内雰囲気中の酸素濃度を低レベルに維持する必要
がある。炉内酸素濃度は、加熱用燃料の空燃比の他に、
炉内に侵入してくる外気量によっても左右される。その
炉内への外気侵入には二つのケースがあり、一つは抽
出扉を開いて炉から被加熱物を取り出す際に抽出口から
炉内に侵入するケース、他は抽出扉が閉じているとき
に、その扉と炉体との間の隙間から侵入するケースであ
る。したがって炉内の酸素濃度は、加熱燃料の燃焼用空
気量並びに前記，の侵入外気量により制御できると
いえる。2. Description of the Related Art For example, in a steel slab heating furnace that heats a steel slab as a material to be heated by burning fuel in the furnace, when the steel slab is heated to a predetermined temperature, oxygen in the furnace is heated. As a result, the billet surface is oxidized to form scale. If oxide scale is present, the quality of the product will be impaired in the subsequent process, so it must be removed as an impurity, and yield loss (scale loss)
Becomes In order to minimize this scale loss, it is necessary to keep the oxygen concentration in the furnace atmosphere during heating at a low level. The oxygen concentration in the furnace is determined by the air-fuel ratio of the heating fuel,
It also depends on the amount of outside air entering the furnace. There are two cases of outside air infiltration into the furnace, one is the case where the extraction door is opened and the object enters the furnace through the extraction port when removing the object to be heated from the furnace, and the other is the case where the extraction door is closed Sometimes, it enters through a gap between the door and the furnace body. Therefore, it can be said that the oxygen concentration in the furnace can be controlled by the amount of combustion air of the heating fuel and the amount of invasion outside air.
【０００３】従来の炉内酸素濃度の制御方法としては、
一酸化炭素濃度及び酸素濃度を測定し、その測定値に基
づいて加熱炉バーナの空燃比制御と炉圧制御とを同時に
行う方法（特開昭５５−１５５１８４号公報）や、炉の
扉開閉時に酸素濃度を一定に保つように排ガスダンパの
開度を調整して炉圧を高め侵入外気量を低減させるもの
（特開昭５９−１８２９２７号公報）等がある。[0003] Conventional methods for controlling the oxygen concentration in the furnace include:
A method in which the concentration of carbon monoxide and the concentration of oxygen are measured, and the air-fuel ratio control of the heating furnace burner and the furnace pressure are simultaneously controlled based on the measured values (Japanese Patent Laid-Open No. 55-155184). There is one that adjusts the opening degree of the exhaust gas damper so as to keep the oxygen concentration constant, thereby increasing the furnace pressure and reducing the amount of invading outside air (Japanese Patent Laid-Open No. 59-182927).
【０００４】[0004]
【発明が解決しようとする課題】上記従来技術では、共
に酸素濃度，一酸化炭素濃度を測定して排ガスダンパの
開度又は加熱バーナの空燃比を制御している。これらの
方法で、定常的な空燃比の乱れ等による酸素濃度上昇を
防止することは十分可能と考えられる。しかし炉から被
加熱材を取り出す際に、開いた抽出口から侵入する外気
による炉内の酸素濃度の上昇防止に関しては十分とはい
えず、被加熱材の表面酸化を防ぎきれないおそれがあ
る。そこで、このような外気侵入による炉内の酸素濃度
の変動を抑制するべく、炉内加熱バーナとは別に抽出口
付近に可燃性ガスの噴出孔を設けて、そこから流量を制
御しつつ噴出させた可燃性ガスを燃焼させて侵入外気中
の酸素を消費することにより炉内を無酸化雰囲気とする
技術が特開昭５７−１４９４１７号公報に提示されてい
る。In the above prior arts, both the oxygen concentration and the carbon monoxide concentration are measured to control the opening of the exhaust gas damper or the air-fuel ratio of the heating burner. It is considered sufficiently possible to prevent an increase in the oxygen concentration due to a steady air-fuel ratio turbulence or the like by using these methods. However, when taking out the material to be heated from the furnace, it is not enough to prevent the oxygen concentration in the furnace from rising due to the outside air entering through the open extraction port, and there is a possibility that the surface oxidation of the material to be heated cannot be prevented. Therefore, in order to suppress the fluctuation of oxygen concentration in the furnace due to such outside air intrusion, a flammable gas injection hole is provided near the extraction port separately from the furnace heating burner, and the flammable gas is discharged from there while controlling the flow rate. Japanese Patent Application Laid-Open No. Sho 57-149417 discloses a technique in which a combustible gas is burned to consume oxygen in the intruding outside air to make the inside of the furnace a non-oxidizing atmosphere.
【０００５】しかしながら、この場合は、炉内の一酸化
炭素濃度を検出して、それを所定の一定値に制御するこ
とで可燃性ガスの噴出量を制御するものであるから、抽
出扉の開閉時のように２０〜３０秒間という僅かな時間
の炉圧変動で急激に侵入する外気による炉内の酸素濃度
上昇を迅速に防止することは、一酸化炭素濃度測定系の
応答性等などからみて難しいという問題がある。However, in this case, the concentration of carbon monoxide in the furnace is detected and controlled to a predetermined constant value to control the amount of flammable gas ejected. The rapid prevention of an increase in the oxygen concentration in the furnace due to outside air that suddenly enters due to a slight change in the furnace pressure of 20 to 30 seconds as in the case of time is considered from the viewpoint of the response of the carbon monoxide concentration measurement system and the like. There is a problem that is difficult.
【０００６】すなわち、噴出孔からの可燃性ガスの噴出
量の制御は、次の手順を経て行われる。抽出扉が開放
されると、炉内の圧力が低下する。炉圧低下に伴い外
部から空気が炉内に侵入する。侵入空気に希釈されて
炉内の一酸化炭素の濃度が低下する。その一酸化炭素
濃度の低下を一酸化炭素濃度検出器で検出し、制御手段
を介して前記可燃性ガスの流量を増やすことにより、一
酸化炭素濃度を所定値に保つ。このような手順を経るの
で、扉を開放した時点から、侵入空気で希釈された一酸
化炭素の濃度低下を検出するまでの間に時間遅れが生じ
ることは避けられない。That is, the control of the amount of flammable gas to be ejected from the ejection holes is performed through the following procedure. When the extraction door is opened, the pressure in the furnace decreases. Air enters the furnace from the outside as the furnace pressure decreases. The concentration of carbon monoxide in the furnace is reduced by dilution into the intruding air. The decrease in the carbon monoxide concentration is detected by a carbon monoxide concentration detector, and the flow rate of the flammable gas is increased via a control means, thereby keeping the carbon monoxide concentration at a predetermined value. Since such a procedure is performed, it is inevitable that a time delay occurs from when the door is opened to when the decrease in the concentration of carbon monoxide diluted with the intruding air is detected.
【０００７】そこで本発明は、このような従来の問題点
に着目してなされたものであり、抽出扉を開閉する時に
生じるような僅か数十秒の炉圧変動であっても迅速に対
応して、侵入空気による酸素濃度上昇を防止し炉内を常
時低酸素濃度に保つことが可能な炉内雰囲気制御方法と
その装置を提供することを目的としている。Accordingly, the present invention has been made in view of such a conventional problem, and can quickly respond to a furnace pressure fluctuation of only several tens of seconds that occurs when opening and closing the extraction door. Accordingly, it is an object of the present invention to provide a furnace atmosphere control method and apparatus capable of preventing an increase in the oxygen concentration due to invading air and keeping the furnace always at a low oxygen concentration.
【０００８】[0008]
【課題を解決するための手段】上記の目的を達成するた
めに、本発明の請求項１に係る炉内雰囲気の制御方法
は、連続式加熱炉の炉内から被加熱材を抽出する際に、
抽出口直近での炉圧値を検出し、その検出炉圧値に応じ
て抽出口直近に設置したノズルから噴出せしめる可燃性
ガスの流量を調整することにより、抽出扉の開閉時の侵
入空気による炉内酸素濃度の上昇を防止することを特徴
とするものである。According to a first aspect of the present invention, there is provided a method for controlling an atmosphere in a furnace according to the present invention, wherein a material to be heated is extracted from the furnace of a continuous heating furnace. ,
By detecting the furnace pressure value near the extraction port and adjusting the flow rate of the flammable gas ejected from the nozzle installed near the extraction port according to the detected furnace pressure value, It is characterized in that an increase in the oxygen concentration in the furnace is prevented.
【０００９】また、本発明の請求項２に係る炉内雰囲気
の制御方法は、連続式加熱炉の抽出口直近の炉圧値を常
時検出し、その検出炉圧値に応じて抽出口直近に設置し
たノズルから噴出せしめる可燃性ガスの流量を調整する
ことにより、抽出扉が閉じている状態でその扉と炉体と
の隙間から侵入する空気による炉内酸素濃度の上昇を防
止することを特徴とするものである。According to a second aspect of the present invention, there is provided a method for controlling the atmosphere in a furnace, wherein a furnace pressure value immediately near an extraction port of a continuous heating furnace is constantly detected, and the furnace pressure value is detected immediately in accordance with the detected furnace pressure value. By adjusting the flow rate of flammable gas ejected from the installed nozzle, it is possible to prevent the oxygen concentration in the furnace from rising due to air entering through the gap between the extraction door and the furnace body when the extraction door is closed It is assumed that.
【００１０】本発明の請求項３に係る炉内雰囲気制御装
置は、連続式加熱炉の抽出口直近に炉内圧力検出器を配
置するとともに、抽出口直近に配置した可燃性ガス噴出
ノズルと、前記炉内圧力検出器で検出した炉圧に応じて
前記ノズルの可燃性ガス噴出量を迅速に制御する制御手
段とを備えてなるものである。A furnace atmosphere control apparatus according to a third aspect of the present invention includes a furnace pressure detector disposed immediately adjacent to an extraction port of a continuous heating furnace, a combustible gas ejection nozzle disposed immediately adjacent to an extraction port, Control means for rapidly controlling the amount of combustible gas ejected from the nozzle in accordance with the furnace pressure detected by the furnace pressure detector.
【００１１】そして、請求項４に係る発明は、上記請求
項３に係る発明である炉内雰囲気制御装置において、前
記可燃性ガス噴出ノズルを、抽出口の下部から上部に向
けてカーテンフレームを形成するように抽出口の下縁部
に配列した。According to a fourth aspect of the present invention, in the furnace atmosphere control device according to the third aspect, the combustible gas ejection nozzle is formed with a curtain frame from a lower portion to an upper portion of an extraction port. It was arranged at the lower edge of the extraction port.
【００１２】ここに、上記請求項１及び請求項２におけ
る「抽出口直近」には、「抽出口の下縁部」をも包含す
るものである。Here, the term "close to the extraction port" in the first and second aspects also includes "the lower edge of the extraction port".
【００１３】[0013]
【発明の実施の形態】以下、本発明の実施の形態を図面
を参照して説明する。図１は、本発明の方法を好適に実
施するための炉内雰囲気制御装置を備えた連続式加熱炉
の出側部近傍の断面略図である。図示の加熱炉１は、被
加熱材である鋼片（以下、ワークという）Ｗを連続的に
焼鈍するもので、炉壁２に囲まれた炉内は、図示されな
い入り側（上流側）から順に、予熱帯，加熱帯及び均熱
帯３の各パートに区分されている。各パートは、それぞ
れに設けてある図外のバーナで燃料を燃焼させることに
より直火で加熱されて、それぞれの所定温度に保持され
る。入り側から炉内に送入されたワークＷは、ビーム４
上を搬送されつつ加熱されて抽出口５に到達する。抽出
口５は、その外側に配設されている上下スライド式の抽
出扉６で開閉されるようになっている。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic cross-sectional view showing the vicinity of an outlet side of a continuous heating furnace provided with a furnace atmosphere control device for suitably implementing the method of the present invention. The illustrated heating furnace 1 continuously anneals a steel slab (hereinafter, referred to as a workpiece) W as a material to be heated, and the inside of a furnace surrounded by a furnace wall 2 is arranged from an entrance side (upstream side) not shown. In order, it is divided into each part of pre-tropical zone, heating zone, and solitary zone 3. Each part is heated by an open flame by burning fuel with a burner (not shown) provided for each part, and is maintained at a predetermined temperature. The workpiece W sent into the furnace from the entrance side is a beam 4
It is heated while being transported above and reaches the extraction port 5. The extraction port 5 is opened and closed by a vertically slidable extraction door 6 provided outside thereof.
【００１４】その抽出口５の下側の縁部に、可燃性ガス
噴出用のノズル７が、抽出口５の下部から上部に向けて
カーテンフレーム７ａを形成するように配設してある。
前記ノズル７に可燃性ガスとして例えば単味のＭガス
（発熱量２７００ｋｃｌ／Ｎｍ 3 ）を供給する可燃性ガ
ス供給管８が炉外から炉壁２を貫いて配管されている。
その配管の途中にガス流量制御弁９及びガス流量検出器
１０が装着されており、それらの信号回路が、制御装置
１１に接続されている。A combustible gas is provided on the lower edge of the extraction port 5.
The nozzle 7 for ejection is directed from the lower part of the extraction port 5 to the upper part.
It is arranged so as to form the curtain frame 7a.
For example, plain M gas is used as a flammable gas in the nozzle 7.
(Calorific value 2700 kcl / Nm Three) To supply flammable gas
A water supply pipe 8 is piped through the furnace wall 2 from outside the furnace.
Gas flow control valve 9 and gas flow detector
10 are mounted and their signal circuits are
11 is connected.
【００１５】また、抽出口５の下部の直ぐ近く（できる
だけ近い方がよい）において炉内の圧力を検出するべく
炉圧検出器１２の検出端１２ａが抽出口５の直近に設置
され、その炉圧検出器１２の出力信号が制御装置１１に
入力されるようにしてある。Further, a detection end 12a of a furnace pressure detector 12 is installed immediately near the extraction port 5 to detect the pressure in the furnace immediately near the lower portion of the extraction port 5 (preferably as close as possible). An output signal of the pressure detector 12 is input to the control device 11.
【００１６】制御装置１１は、炉圧検出器１２で検出し
た炉圧に応じてノズル７の可燃性ガス噴出量を迅速に制
御する制御手段であり、炉圧検出器１２の検出値と抽出
口５からの侵入空気量との関係を予め実験的に求めた計
算式またはテーブルが記憶させてある。なお、当該炉圧
−侵入空気量の関係は、ワークＷの未抽出時（抽出扉６
の閉時）及び抽出時（抽出扉６の開閉動作時）毎に求め
てある。そして、実操業では常時炉圧検出器１２からの
炉圧指示値を監視して、その指示値に応じた侵入空気量
を算定し、当該侵入空気を全て燃焼に寄与せしめる量の
可燃性ガス（理論量のＭガス）をノズル７から噴出させ
るようにガス流量制御弁９の開度を調整するものであ
る。The control device 11 is a control means for quickly controlling the amount of flammable gas ejected from the nozzle 7 in accordance with the furnace pressure detected by the furnace pressure detector 12, and detects the detected value of the furnace pressure detector 12 and the extraction port. The relationship with the amount of intruding air from No. 5 is stored in advance by a calculation formula or a table experimentally obtained in advance. The relationship between the furnace pressure and the amount of invading air is determined when the work W is not extracted (extraction door 6).
At the time of closing) and at the time of extraction (at the time of opening / closing operation of the extraction door 6). In the actual operation, the furnace pressure indicator value from the furnace pressure detector 12 is constantly monitored, the amount of intruded air is calculated in accordance with the indicated value, and the amount of the flammable gas (e.g. The opening of the gas flow control valve 9 is adjusted so that the theoretical amount of M gas is ejected from the nozzle 7.
【００１７】図２は、抽出扉６を開けた時の、抽出口５
からの外気侵入の流れを模式的に示している。抽出扉６
が開くと、抽出口５の上部から炉内ガス１５が炉外へ流
出するのと入れ替えに、外気１６が抽出口５の下部から
炉内へ流入して炉床へと流れ込む。これに同期して先ず
抽出口５近傍の炉圧が変動する。実際の操業では、常時
炉圧検出器１２の指示値を監視している。この炉圧変動
は、加熱炉出側にある抽出口５の直近に配置した炉圧検
出器１２の検出端１２ａでいち早く捉えることができる
から、制御装置１１へは時間遅れなしにその炉圧信号が
発信される。制御装置１１はこれに基づき外気１６の流
入量を算出するとともに、その外気中の含有酸素を完全
に消費できる量の可燃性ガス量を即時に算定し、これを
基準としてノズル７への可燃性ガス量を制御する。かく
して、ノズル７からは侵入外気１６の流量に見合う流量
の可燃性ガスが、抽出口５の下部から上部に向けてカー
テン状に噴出されると同時に、炉内ガス１５の高温で侵
入外気１６中の酸素と急激に反応して燃焼しカーテンフ
レーム７ａが形成される。このように、抽出口５の下部
から上部へとカーテンフレーム７ａを形成するようにノ
ズル７を設置すると、可燃性ガスの燃焼効率が向上す
る。後続の侵入外気１６の酸素もこうして次々と完全に
捕捉され消費されるから、炉内酸素濃度の上昇は抑制さ
れて低位に維持される。FIG. 2 shows the extraction port 5 when the extraction door 6 is opened.
3 schematically shows the flow of outside air intrusion from the airbag. Extraction door 6
Is opened, the outside air 16 flows into the furnace from the lower part of the extraction port 5 and flows into the hearth instead of the in-furnace gas 15 flowing out of the furnace from the upper part of the extraction port 5. In synchronization with this, first, the furnace pressure near the extraction port 5 fluctuates. In the actual operation, the indicated value of the furnace pressure detector 12 is constantly monitored. This furnace pressure fluctuation can be detected as soon as possible at the detection end 12a of the furnace pressure detector 12 disposed immediately adjacent to the extraction port 5 on the exit side of the heating furnace. Is transmitted. The control device 11 calculates the inflow amount of the outside air 16 based on this, and immediately calculates the amount of the flammable gas that can completely consume the oxygen contained in the outside air. Control the gas volume. Thus, the combustible gas having a flow rate corresponding to the flow rate of the intruding outside air 16 is ejected from the nozzle 7 in a curtain shape from the lower part of the extraction port 5 toward the upper part, and at the same time, the high temperature of the furnace gas 15 causes Rapidly reacts with the oxygen to burn and form the curtain frame 7a. As described above, when the nozzles 7 are provided so as to form the curtain frame 7a from the lower part to the upper part of the extraction port 5, the combustion efficiency of the combustible gas is improved. Since the oxygen of the subsequent invading outside air 16 is also completely captured and consumed one after another in this manner, the increase in the oxygen concentration in the furnace is suppressed and maintained at a low level.
【００１８】すなわち、特開昭５５−１５５１８４号及
び特開昭５９−１８２９２７号の場合は、圧力検出器
（加熱炉の入り側又は中間位置に設置している）で検出
した炉圧が予め設定されている圧力制御指標より小さい
とき、ダンパの開度を絞り炉圧を上昇させて侵入空気量
を減少させることにより炉内残存酸素量を抑制する。こ
れに対して、本発明の場合は、空気侵入を抑制する代わ
りに、その侵入空気量に見合う量の可燃性ガスを供給し
て侵入空気中の酸素を完全に消費することにより炉内酸
素濃度の上昇を防止する。That is, in the case of JP-A-55-155184 and JP-A-59-182927, the furnace pressure detected by a pressure detector (installed at the entrance of the heating furnace or at an intermediate position) is set in advance. When the pressure control index is smaller than the set pressure control index, the amount of residual oxygen in the furnace is suppressed by reducing the opening of the damper and increasing the furnace pressure to reduce the amount of intruded air. On the other hand, in the case of the present invention, instead of suppressing the intrusion of air, the amount of flammable gas corresponding to the amount of intruded air is supplied to completely consume oxygen in the intruded air, thereby reducing the oxygen concentration in the furnace. To prevent the rise.
【００１９】しかも、可燃性ガスの噴出量の制御は、特
開昭５７−１４９４１７号の場合のように、空気侵入に
より遅れを伴って生じる炉内の一酸化炭素濃度の変化を
検出して行うものではなく、空気侵入に同期して発生す
る抽出口の炉圧変動に基づいて行うものであるから、殆
ど時間遅れなしに、刻々と侵入する外気中の酸素をリア
ルタイムで消費させることができる。In addition, the control of the amount of the flammable gas to be ejected is performed by detecting a change in the concentration of carbon monoxide in the furnace caused by a delay due to the intrusion of air as in Japanese Patent Application Laid-Open No. 57-149417. Instead, it is performed based on the furnace pressure fluctuation of the extraction port generated in synchronization with the intrusion of air, so that the oxygen in the outside air that intrudes momentarily can be consumed in real time with almost no time delay.
【００２０】したがって、本発明によれば、抽出扉の開
閉時のように数十秒間という僅かな時間の炉圧変動で急
激に侵入する外気による炉内酸素濃度上昇でも、迅速に
防止することが可能である。Therefore, according to the present invention, it is possible to quickly prevent an increase in the oxygen concentration in the furnace due to outside air that suddenly enters due to a change in the furnace pressure for a few seconds, such as when the extraction door is opened and closed. It is possible.
【００２１】また、抽出扉６が閉じているときに、炉壁
２と抽出扉６との間の隙間から侵入する外気にたいして
は、先に述べたワークＷの未抽出時（抽出扉６の閉時）
における炉圧−侵入空気量の関係値を適用することによ
り、同様に可燃性ガスを供給をその侵入空気量に見合う
ように制御することにより、侵入空気中の酸素を完全に
消費させて炉内酸素濃度の上昇を防止することができ
る。When the extraction door 6 is closed, the outside air that enters through the gap between the furnace wall 2 and the extraction door 6 is not exposed when the work W is not extracted as described above (when the extraction door 6 is closed). Time)
Similarly, by applying the relationship value of the furnace pressure and the amount of intruding air in the above, the supply of flammable gas is controlled so as to match the amount of intruding air, so that the oxygen in the intruding air is completely consumed and the furnace An increase in oxygen concentration can be prevented.
【００２２】なお、上記実施形態では、可燃性ガス噴出
用のノズル７を抽出口５の下縁部に設置した場合を述べ
たが、抽出口５の直近の炉内側に設けてもよい。以下、
比較実験により、本発明の効果を具体的に説明する。In the above embodiment, the case where the combustible gas jetting nozzle 7 is provided at the lower edge of the extraction port 5 has been described, but it may be provided inside the furnace immediately near the extraction port 5. Less than,
The effects of the present invention will be specifically described by comparative experiments.
【００２３】（１） 試験装置 加熱炉：幅１３ｍ×高さ６ｍ×長さ５１ｍ 抽出口：幅１３ｍ×高さ０．３ｍ ノズルの容量：１４．５×１０6 Ｋｃａｌ／Ｈｒ（Ｔｏ
ｔａｌ） （２） 試験方法（条件） 実施例：Ｏ2 制御、炉圧制御、ノズルからの可燃性ガス
量のＰＩＤ制御 比較例：Ｏ2 制御、炉圧制御 （３） 試験結果 図３に、実施例の炉内酸素濃度の経時変化及び抽出扉開
時毎のＭガス吐出流量を示す。この場合は、抽出口直近
での炉圧変動に基づき単味のＭガスを適正量づつノズル
から噴出させると、侵入空気（酸素）が燃焼に使用され
て炉内酸素濃度は低位に維持できた。(1) Test apparatus Heating furnace: width 13 m × height 6 m × length 51 m Extraction port: width 13 m × height 0.3 m Nozzle capacity: 14.5 × 10 6 Kcal / Hr (To
tal) (2) Test method (conditions) Example: O 2 control, control the furnace pressure, combustible gas of PID control comparative example of the nozzle: the O 2 control, control the furnace pressure (3) Test results Figure 3, 5 shows the change over time in the oxygen concentration in the furnace and the M gas discharge flow rate each time the extraction door is opened in the example. In this case, when a simple amount of M gas was ejected from the nozzle in an appropriate amount based on the furnace pressure fluctuation immediately near the extraction port, the invading air (oxygen) was used for combustion and the oxygen concentration in the furnace could be maintained at a low level. .
【００２４】また、図４に、比較例の炉内酸素濃度の経
時変化を示す。炉圧制御，酸素濃度制御のみでは抽出扉
開閉時の炉内酸素濃度増加を完全に抑えることはでき
ず、その結果スパイク的に酸素濃度は増加する。FIG. 4 shows the change over time in the oxygen concentration in the furnace of the comparative example. The furnace pressure control and the oxygen concentration control alone cannot completely suppress the increase in the oxygen concentration in the furnace when the extraction door is opened and closed, and as a result, the oxygen concentration increases spikes.
【００２５】なお、上記実施形態では、ノズル７から可
燃性ガスを直接噴出させるようにしたが、侵入空気の消
費速度を向上させるため可燃性ガスを予熱するようにし
ても良い。In the above embodiment, the flammable gas is directly ejected from the nozzle 7, but the flammable gas may be preheated in order to improve the consumption speed of the invading air.
【００２６】また、同じく可燃性ガスに理論空気量以下
の空気を予混合し、未燃フレームを形成させるようにし
ても良い。Alternatively, the combustible gas may be premixed with air having a theoretical air amount or less to form an unburned flame.
【００２７】[0027]
【発明の効果】以上説明したように、本発明によれば、
加熱炉の抽出口の直近の炉圧を検出して、可燃性ガスの
噴出量を制御するものとしたため、数十秒というごく短
時間の炉圧変動に伴って炉内に侵入する空気を時間遅れ
なしに即座に燃焼に寄与させることができて、炉内の酸
素濃度を低位に維持できるという効果を奏する。As described above, according to the present invention,
Since the amount of flammable gas blown out is controlled by detecting the furnace pressure immediately near the extraction port of the heating furnace, the air entering the furnace with the furnace pressure fluctuation for a very short time of several tens of seconds is measured. It is possible to immediately contribute to combustion without delay, and it is possible to maintain the oxygen concentration in the furnace at a low level.
【図１】本発明の炉内雰囲気制御装置の概要を示す断面
図である。FIG. 1 is a cross-sectional view showing an outline of a furnace atmosphere control device of the present invention.
【図２】抽出扉開放時に抽出口より侵入する外気流の模
式図である。FIG. 2 is a schematic diagram of an outside air flow entering from an extraction port when an extraction door is opened.
【図３】本発明の方法による炉内酸素濃度の経時変化及
び可燃性ガス流量のグラフである。FIG. 3 is a graph showing a change in oxygen concentration in a furnace with time and a flow rate of combustible gas according to the method of the present invention.
【図４】従来の炉内雰囲気制御による炉内酸素濃度の経
時変化のグラフである。FIG. 4 is a graph showing a change with time of oxygen concentration in a furnace by conventional furnace atmosphere control.
１ 加熱炉 ５ 抽出口 ６ 抽出扉 ７ ノズル（可燃性ガス噴出用） ９ ガス流量制御弁 １１ 制御装置 １２ 炉圧検出器 １２ａ 検出端 DESCRIPTION OF SYMBOLS 1 Heating furnace 5 Extraction port 6 Extraction door 7 Nozzle (for flammable gas ejection) 9 Gas flow control valve 11 Controller 12 Furnace pressure detector 12a Detection end
───────────────────────────────────────────────────── フロントページの続き (72)発明者 中塚 伸治 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 大石 英之 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 (72)発明者 前田 一郎 千葉県千葉市中央区川崎町１番地 川崎製 鉄株式会社千葉製鉄所内 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Shinji Nakatsuka 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Prefecture Inside the Chiba Works of Steel Corporation (72) Inventor Hideyuki Oishi 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba (72) Inventor Ichiro Maeda 1 Kawasaki-cho, Chuo-ku, Chiba-shi, Chiba Chiba Works Chiba Works
Claims (4)
する際に、抽出口直近での炉圧値を検出し、その検出炉
圧値に応じて抽出口直近に設置したノズルから噴出せし
める可燃性ガスの流量を調整することにより、抽出扉の
開閉時の侵入空気による炉内酸素濃度の上昇を防止する
ことを特徴とする加熱炉内雰囲気制御方法。When extracting a material to be heated from inside a furnace of a continuous heating furnace, a furnace pressure value near the extraction port is detected, and a nozzle installed near the extraction port is detected in accordance with the detected furnace pressure value. A method for controlling the atmosphere in a heating furnace, wherein the flow rate of flammable gas to be ejected is adjusted to prevent an increase in oxygen concentration in the furnace due to invading air when the extraction door is opened and closed.
時検出し、その検出炉圧値に応じて抽出口直近に設置し
たノズルから噴出せしめる可燃性ガスの流量を調整する
ことにより、抽出扉が閉じている状態でその扉と炉体と
の隙間から侵入する空気による炉内酸素濃度の上昇を防
止することを特徴とする加熱炉内雰囲気制御方法。2. A method of continuously detecting a furnace pressure value immediately near an extraction port of a continuous heating furnace and adjusting a flow rate of a flammable gas ejected from a nozzle installed immediately near the extraction port according to the detected furnace pressure value. A method for controlling the atmosphere in a heating furnace, wherein an increase in the oxygen concentration in the furnace due to air entering through a gap between the extraction door and the furnace body in a state where the extraction door is closed is prevented.
出器を配置するとともに、抽出口直近に配置した可燃性
ガスノズルと、前記炉内圧力検出器で検出した炉圧に応
じて前記ノズルの可燃性ガス噴出量を迅速に制御する制
御手段とを備えてなる炉内雰囲気制御装置。3. An in-furnace pressure detector is disposed in the vicinity of the extraction port of the continuous heating furnace, and the flammable gas nozzle disposed in the vicinity of the extraction port and the furnace pressure detected in accordance with the furnace pressure detected by the in-furnace pressure detector. A furnace atmosphere control device comprising: a control unit for rapidly controlling the amount of combustible gas ejected from a nozzle.
下部から上部に向けてカーテンフレームを形成するよう
に抽出口の下縁部に配列してある請求項３記載の炉内雰
囲気制御装置。4. The furnace atmosphere control device according to claim 3, wherein the combustible gas ejection nozzles are arranged at a lower edge of the extraction port so as to form a curtain frame from a lower portion to an upper portion of the extraction port. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33567197A JPH11172326A (en) | 1997-12-05 | 1997-12-05 | Method for controlling atmosphere in furnace and device therefor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33567197A JPH11172326A (en) | 1997-12-05 | 1997-12-05 | Method for controlling atmosphere in furnace and device therefor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH11172326A true JPH11172326A (en) | 1999-06-29 |
Family
ID=18291217
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33567197A Pending JPH11172326A (en) | 1997-12-05 | 1997-12-05 | Method for controlling atmosphere in furnace and device therefor |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH11172326A (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002057501A1 (en) * | 2001-01-17 | 2002-07-25 | Kawasaki Steel Corporation | Heating furnace with regenerative burners and method of operating the heating furnace |
| JP2013181204A (en) * | 2012-03-01 | 2013-09-12 | Jfe Steel Corp | Heating furnace abnormality detection method |
| KR101941689B1 (en) * | 2017-10-20 | 2019-01-24 | 주식회사 포스코 | Fired furnace control apparatus and fired furnace control method |
| JP2020183818A (en) * | 2019-04-26 | 2020-11-12 | Ｄｏｗａサーモテック株式会社 | Curtain burner and heat-treatment facility |
| WO2024048028A1 (en) * | 2022-08-29 | 2024-03-07 | 中外炉工業株式会社 | Combustion facility |
-
1997
- 1997-12-05 JP JP33567197A patent/JPH11172326A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2002057501A1 (en) * | 2001-01-17 | 2002-07-25 | Kawasaki Steel Corporation | Heating furnace with regenerative burners and method of operating the heating furnace |
| US6644962B2 (en) | 2001-01-17 | 2003-11-11 | Kawasaki Steel Corporation | Heating furnace having heat regenerating burners and operation method thereof |
| EP1757707A3 (en) * | 2001-01-17 | 2007-06-20 | JFE Steel Corporation | Heating furnace having heat regenerating burners and operation method thereof |
| JP2013181204A (en) * | 2012-03-01 | 2013-09-12 | Jfe Steel Corp | Heating furnace abnormality detection method |
| KR101941689B1 (en) * | 2017-10-20 | 2019-01-24 | 주식회사 포스코 | Fired furnace control apparatus and fired furnace control method |
| JP2020183818A (en) * | 2019-04-26 | 2020-11-12 | Ｄｏｗａサーモテック株式会社 | Curtain burner and heat-treatment facility |
| WO2024048028A1 (en) * | 2022-08-29 | 2024-03-07 | 中外炉工業株式会社 | Combustion facility |
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