JP2022036649A - Pig iron melting determination method, pig iron melting treatment method, and pig iron melted amount estimation method - Google Patents
Pig iron melting determination method, pig iron melting treatment method, and pig iron melted amount estimation method Download PDFInfo
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- 229910000805 Pig iron Inorganic materials 0.000 title claims abstract description 116
- 238000000034 method Methods 0.000 title claims abstract description 62
- 238000002844 melting Methods 0.000 title abstract description 24
- 230000008018 melting Effects 0.000 title abstract description 24
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims abstract description 104
- 239000007789 gas Substances 0.000 claims abstract description 66
- 229910002092 carbon dioxide Inorganic materials 0.000 claims abstract description 52
- 239000001569 carbon dioxide Substances 0.000 claims abstract description 52
- 239000000446 fuel Substances 0.000 claims abstract description 20
- 238000005070 sampling Methods 0.000 claims abstract description 5
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 61
- 239000001301 oxygen Substances 0.000 claims description 61
- 229910052760 oxygen Inorganic materials 0.000 claims description 61
- 238000004090 dissolution Methods 0.000 claims description 49
- 238000002485 combustion reaction Methods 0.000 claims description 12
- 238000010309 melting process Methods 0.000 claims description 7
- 239000000567 combustion gas Substances 0.000 abstract description 4
- NJFMNPFATSYWHB-UHFFFAOYSA-N ac1l9hgr Chemical compound [Fe].[Fe] NJFMNPFATSYWHB-UHFFFAOYSA-N 0.000 description 16
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 229910052751 metal Inorganic materials 0.000 description 8
- 239000002184 metal Substances 0.000 description 8
- 239000002893 slag Substances 0.000 description 8
- 238000006243 chemical reaction Methods 0.000 description 4
- 229910052742 iron Inorganic materials 0.000 description 4
- 238000005259 measurement Methods 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 230000006399 behavior Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 150000001721 carbon Chemical class 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000000155 melt Substances 0.000 description 1
- 239000001294 propane Substances 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000011179 visual inspection Methods 0.000 description 1
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Abstract
Description
本発明は、銑鉄の溶解処理時における銑鉄の溶解判定方法、銑鉄の溶解処理方法、及び、銑鉄の溶解量推定方法に関するものである。 The present invention relates to a method for determining the dissolution of pig iron at the time of melting treatment of pig iron, a method for dissolving pig iron, and a method for estimating the amount of dissolution of pig iron.
高炉から出銑された溶銑は、例えば、トーピードカー等の移送容器に移して転炉に移動される。
ここで、溶銑を転炉に装入する前に、トーピードカー等の移送容器内において、排滓、脱珪、脱燐、脱硫などの転炉外精錬を行うことがある。これらの処理過程において、溶銑を出銑できずに長期滞留した場合に、トーピードカー等の溶銑が固化することがある。
The hot metal discharged from the blast furnace is transferred to a transfer container such as a torpedo car and transferred to a converter.
Here, before charging the hot metal into the converter, out-of-converter refining such as slag removal, desiliconization, dephosphorization, and desulfurization may be performed in a transfer container such as a torpedo car. In these treatment processes, if the hot metal cannot be exposed and stays for a long period of time, the hot metal such as a torpedo car may solidify.
このため、トーピードカー等の移送容器においては、内部で固化した銑鉄を溶解して排出する銑鉄溶解処理作業を行う必要がある。
銑鉄溶解処理作業においては、トーピードカー等の移送容器内に燃料と酸素を含む助燃ガスを供給して燃焼させ、この燃焼熱によって固化した溶銑を溶解する。ここで、銑鉄が溶解した後に酸素を含む助燃ガスにより銑鉄が過酸化状態となり、酸化鉄を多量に含むスラグが発生すると、このスラグによって耐火物が劣化するおそれがある。このため、溶解した銑鉄を定期的に排出する必要がある。
Therefore, in a transfer container such as a torpedo car, it is necessary to perform a pig iron melting treatment operation for melting and discharging the pig iron solidified inside.
In the pig iron melting treatment work, a combustion auxiliary gas containing fuel and oxygen is supplied to a transfer container such as a torpedo car and burned, and the hot metal solidified by the combustion heat is melted. Here, if the pig iron is in a peroxidized state due to the combustion assisting gas containing oxygen after the pig iron is dissolved and slag containing a large amount of iron oxide is generated, the refractory material may be deteriorated by the slag. Therefore, it is necessary to periodically discharge the melted pig iron.
移送容器内の銑鉄の溶解の有無の判定を目視で行う場合には、一時的に溶解処理を中断する必要がある。このため、熱効率が低下してしまい、効率良く銑鉄の溶解作業を行うことができなった。そこで、目視以外の方法で、銑鉄の溶解の有無を判断する手法が求められている。 When visually determining the presence or absence of melting of pig iron in the transfer container, it is necessary to temporarily suspend the melting process. For this reason, the thermal efficiency is lowered, and the pig iron melting work cannot be performed efficiently. Therefore, there is a demand for a method for determining the presence or absence of dissolution of pig iron by a method other than visual inspection.
ここで、特許文献１においては、排ガス中の一酸化炭素ＣＯと二酸化炭素ＣＯ２の割合の変化から、固体鉄源の溶解の有無を判定する方法が提案されている。
また、特許文献２においては、電気炉において、排ガス成分濃度が閾値未満となったときに、原料が溶解したと判断する方法が提案されている。
Here,
Further,
ところで、特許文献１，２においては、侵入空気の影響を考慮していないため、トーピードカー等の開放された空間での溶解の判定には適用できなかった。このため、従来は、トーピードカー等の移送容器内で固化した銑鉄の溶解の有無を判断する手法はなく、やはり、目視で確認する必要があった。
By the way, in
本発明は、前述した状況に鑑みてなされたものであって、トーピードカー等の移送容器内で固化した銑鉄を溶解処理する際に、銑鉄の溶解の有無を精度良く判定することが可能な銑鉄の溶解判定方法、この銑鉄の溶解判定方法を利用した銑鉄の溶解処理方法及び銑鉄の溶解量推定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 above-mentioned situation, and is capable of accurately determining the presence or absence of melting of pig iron when melting pig iron solidified in a transfer container such as a torpedo car. It is an object of the present invention to provide a melting determination method, a method for melting pig iron using this method for determining melting of pig iron, and a method for estimating the amount of melting of pig iron.
上記の課題を解決するために、本発明者らが鋭意検討した結果、以下のような知見を得た。
排ガス温度、燃料流量、助燃ガス流量が定常であれば、燃焼量論計算上は排ガス成分系も定常となる。しかし、実際に、トーピードカー内で固化した銑鉄の溶解処理時の排ガス濃度を観察すると、排ガス温度、燃料流量、助燃ガス流量が定常状態でも、排ガスにおいて酸素濃度が低下し、二酸化炭素濃度が増大している状態が観察された。排ガスに混入する空気量の変動であれば、酸素および二酸化炭素は同じ傾向を示すと考えられるが、二種類のガスで異なる挙動を示したことから、銑鉄が溶解してスラグになる際に、飽和した炭素と酸素が結びつき二酸化炭素を発生させる反応が起きていると考えた。
As a result of diligent studies by the present inventors in order to solve the above problems, the following findings were obtained.
If the exhaust gas temperature, fuel flow rate, and auxiliary gas flow rate are steady, the exhaust gas component system is also steady in the stoichiometry calculation. However, when actually observing the exhaust gas concentration during the melting process of the pig iron solidified in the torpedo car, the oxygen concentration in the exhaust gas decreases and the carbon dioxide concentration increases even if the exhaust gas temperature, fuel flow rate, and auxiliary gas flow rate are steady. Was observed. Oxygen and carbon dioxide are thought to show the same tendency if the amount of air mixed in the exhaust gas fluctuates, but since the two types of gas showed different behaviors, when pig iron melts into slag, It was thought that a reaction was occurring in which saturated carbon and oxygen were combined to generate carbon dioxide.
本発明は、上述の知見に基づいてなされたものであって、本発明に係る銑鉄の溶解判定方法は、銑鉄溶解処理中に発生する排ガスをサンプリングして測定した実測二酸化炭素濃度と、排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論二酸化炭素濃度と、を比較し、前記実測二酸化炭素濃度が前記理論二酸化炭素濃度よりも一定以上高くなった際に、前記銑鉄が溶解したと判断することを特徴としている。 The present invention has been made based on the above-mentioned findings, and the method for determining the dissolution of pig iron according to the present invention is the measured carbon dioxide concentration measured by sampling the exhaust gas generated during the pig iron dissolution treatment and the exhaust gas temperature. , The theoretical carbon dioxide concentration in the exhaust gas calculated from the combustion assisting gas flow rate, the fuel flow rate, and the invading air amount is compared, and when the measured carbon dioxide concentration becomes higher than a certain level than the theoretical carbon dioxide concentration, the said It is characterized by determining that pig iron has melted.
上述した銑鉄の溶解判定方法においては、銑鉄溶解処理中に発生する排ガス中の実測二酸化炭素濃度と、排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論二酸化炭素濃度と、を比較し、前記実測二酸化炭素濃度が前記理論二酸化炭素濃度よりも一定以上高くなった際に、前記銑鉄が溶解したと判断する構成としているので、銑鉄の溶解の有無を判定することができる。
そして、前記理論二酸化炭素濃度を算出する際に、侵入空気量を考慮していることから、トーピードカー等の開放された空間における銑鉄の溶解の有無を精度良く判定することが可能となる。
In the above-mentioned method for determining the dissolution of iron iron, the measured carbon dioxide concentration in the exhaust gas generated during the iron iron melting process and the theoretical carbon dioxide concentration in the exhaust gas calculated from the exhaust gas temperature, the auxiliary gas flow rate, the fuel flow rate and the invading air amount. When the measured carbon dioxide concentration becomes higher than the theoretical carbon dioxide concentration by a certain amount or more, it is determined that the iron iron has been dissolved. Therefore, it is possible to determine whether or not the iron iron is dissolved. can.
Since the amount of invading air is taken into consideration when calculating the theoretical carbon dioxide concentration, it is possible to accurately determine whether or not pig iron is dissolved in an open space such as a torpedo car.
あるいは、本発明に係る銑鉄の溶解判定方法は、銑鉄溶解処理中に発生する排ガスをサンプリングして測定した実測酸素濃度と、排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論酸素濃度と、を比較し、前記実測酸素濃度が前記理論酸素濃度よりも一定以上低くなった際に、前記銑鉄が溶解したと判断することを特徴としている。 Alternatively, the method for determining the dissolution of iron iron according to the present invention is an exhaust gas calculated from the measured oxygen concentration measured by sampling the exhaust gas generated during the iron iron melting process, the exhaust gas temperature, the auxiliary combustion gas flow rate, the fuel flow rate, and the invading air amount. It is characterized in that the iron iron is determined to have been dissolved when the measured oxygen concentration is lower than the theoretical oxygen concentration by a certain amount or more by comparing with the theoretical oxygen concentration in the medium.
上述した銑鉄の溶解判定方法においては、銑鉄溶解処理中に発生する排ガス中の実測酸素濃度と、排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論酸素濃度と、を比較し、前記実測酸素濃度が前記理論酸素濃度よりも一定以上低くなった際に、前記銑鉄が溶解したと判断する構成としているので、銑鉄の溶解の有無を判定することができる。
そして、前記理論酸素濃度を算出する際に、侵入空気量を考慮していることから、トーピードカー等の開放された空間における銑鉄の溶解の有無を精度良く判定することが可能となる。
In the above-mentioned method for determining the dissolution of iron iron, the measured oxygen concentration in the exhaust gas generated during the iron iron dissolution process, the theoretical oxygen concentration in the exhaust gas calculated from the exhaust gas temperature, the auxiliary gas flow rate, the fuel flow rate, and the invading air amount are used. When the measured oxygen concentration becomes lower than the theoretical oxygen concentration by a certain amount or more, it is determined that the iron iron has been dissolved. Therefore, it can be determined whether or not the iron iron is dissolved.
Since the amount of invading air is taken into consideration when calculating the theoretical oxygen concentration, it is possible to accurately determine whether or not pig iron is dissolved in an open space such as a torpedo car.
ここで、本発明に係る銑鉄の溶解判定方法においては、前記実測二酸化炭素濃度が前記理論二酸化炭素濃度よりも３ｖｏｌ％以上高くなった時点で、前記銑鉄が溶解したと判断する構成としてもよい。
この場合、前記実測二酸化炭素濃度と前記理論二酸化炭素濃度との間に明確な差異が生じており、的確に銑鉄の溶解の有無を判定することができる。
Here, in the method for determining the dissolution of pig iron according to the present invention, it may be determined that the pig iron has been dissolved when the actually measured carbon dioxide concentration becomes 3 vol% or more higher than the theoretical carbon dioxide concentration.
In this case, there is a clear difference between the measured carbon dioxide concentration and the theoretical carbon dioxide concentration, and it is possible to accurately determine the presence or absence of dissolution of pig iron.
あるいは、本発明に係る銑鉄の溶解判定方法においては、前記実測酸素濃度が前記理論酸素濃度よりも３ｖｏｌ％以上低くなった時点で、前記銑鉄が溶解したと判断する構成とする構成としてもよい。
この場合、前記実測酸素濃度と前記理論酸素濃度との間に明確な差異が生じており、的確に銑鉄の溶解の有無を判定することができる。
Alternatively, in the method for determining the dissolution of pig iron according to the present invention, the configuration may be such that the pig iron is determined to have been dissolved when the measured oxygen concentration is 3 vol% or more lower than the theoretical oxygen concentration.
In this case, there is a clear difference between the measured oxygen concentration and the theoretical oxygen concentration, and it is possible to accurately determine the presence or absence of dissolution of pig iron.
本発明に係る銑鉄の溶解処理方法は、上述した銑鉄の溶解判定方法により、銑鉄が溶解したと判断された際に、前記助燃ガス流量及び前記燃料流量の一方又は両方を調整し、前記排ガス中の酸素濃度を低下させることを特徴としている。 In the method for melting pig iron according to the present invention, when it is determined that the pig iron has melted by the above-mentioned method for determining the melting of pig iron, one or both of the auxiliary fuel flow rate and the fuel flow rate are adjusted in the exhaust gas. It is characterized by lowering the oxygen concentration of pig iron.
この構成の銑鉄の溶解処理方法によれば、銑鉄が溶解したと判断した時点で、前記排ガス中の酸素濃度を低下させているので、溶解した銑鉄（溶銑）と酸素の反応によってスラグが多量に生成することを抑制でき、耐火物の劣化を抑制することが可能となる。 According to the method for melting pig iron having this configuration, when it is determined that the pig iron has melted, the oxygen concentration in the exhaust gas is lowered, so that a large amount of slag is generated by the reaction between the melted pig iron (hot metal) and oxygen. It is possible to suppress the generation and to suppress the deterioration of the refractory.
本発明に係る銑鉄の溶解量推定方法は、上述した銑鉄の溶解判定方法により、銑鉄が溶解したと判断された時点からの経過時間に基づいて、前記銑鉄の溶解量を推定することを特徴としている。 The method for estimating the dissolution amount of pig iron according to the present invention is characterized in that the dissolution amount of pig iron is estimated based on the elapsed time from the time when the pig iron is determined to be dissolved by the above-mentioned method for determining the dissolution of pig iron. There is.
この構成の銑鉄の溶解量推定方法によれば、銑鉄が溶解したと判断された時点からの経過時間に基づいて前記銑鉄の溶解量を推定する構成とされているので、銑鉄の溶解量（溶銑量）を精度良く推定することが可能となる。 According to the method for estimating the amount of hot iron dissolved in this configuration, the amount of hot iron dissolved is estimated based on the elapsed time from the time when it is determined that the iron is melted. Amount) can be estimated accurately.
上述のように、本発明によれば、トーピードカー等の移送容器内で固化した銑鉄を溶解処理する際に、銑鉄の溶解の有無を精度良く判定することが可能な銑鉄の溶解判定方法、この銑鉄の溶解判定方法を利用した銑鉄の溶解処理方法及び銑鉄の溶解量推定方法を提供することができる。 As described above, according to the present invention, a method for determining the dissolution of pig iron, which can accurately determine the presence or absence of dissolution of pig iron when the pig iron solidified in a transfer container such as a torpedo car is melted. It is possible to provide a method for dissolving pig iron and a method for estimating the amount of dissolved pig iron using the method for determining the dissolution of pig iron.
以下に、本発明の実施形態である銑鉄の溶解判定方法、及び、この銑鉄の溶解判定方法を利用した銑鉄の溶解処理方法、銑鉄の溶解量推定方法について説明する。なお、本発明は、以下の実施形態に限定されるものではない。 Hereinafter, a method for determining the dissolution of pig iron, a method for determining the dissolution of pig iron using this method for determining the dissolution of pig iron, and a method for estimating the amount of dissolution of pig iron, which are embodiments of the present invention, will be described. The present invention is not limited to the following embodiments.
トーピードカー内で固化した銑鉄を溶解するために、燃焼バーナーから燃料（本実施形態ではプロパンガス）と助燃ガス（本実施形態では酸素ガス）をトーピードカー内に供給して燃焼させ、この燃焼熱によってトーピードカー内を加熱する。このとき、トーピードカーは密閉されていないため、外部から空気が侵入することになる。そして、燃焼によって生じる排ガスは煙突を通じて外部へと排出される。 In order to melt the pig iron solidified in the torpedo car, fuel (propane gas in this embodiment) and auxiliary combustion gas (oxygen gas in this embodiment) are supplied into the torpedo car from a combustion burner and burned, and the combustion heat is used to burn the torpedo car. Heat the inside. At this time, since the torpedo car is not sealed, air will enter from the outside. Then, the exhaust gas generated by combustion is discharged to the outside through the chimney.
本実施形態である銑鉄の溶解判定方法においては、煙突から排出される排ガスをサンプリングし、排ガス温度、二酸化炭素濃度、酸素濃度を、随時、測定する。
このとき、測定間隔は１秒以上６０秒以下の範囲内とすることが好ましい。また、測定値のばらつきの影響を抑えるために、例えば３個以上の測定データの平均値を算出し、実測二酸化炭素濃度、実測酸素濃度を得ることが好ましい。なお、測定データの平均値を算出する際の測定データ個数は４個以上であることがより好ましく、２４０個以上であることがさらに好ましい。本実施形態では、１８００個の測定データから平均値を算出している。
In the method for determining the dissolution of pig iron according to the present embodiment, the exhaust gas discharged from the chimney is sampled, and the exhaust gas temperature, carbon dioxide concentration, and oxygen concentration are measured at any time.
At this time, the measurement interval is preferably in the range of 1 second or more and 60 seconds or less. Further, in order to suppress the influence of variation in the measured values, it is preferable to calculate, for example, the average value of three or more measured data to obtain the measured carbon dioxide concentration and the measured oxygen concentration. The number of measurement data when calculating the average value of the measurement data is more preferably 4 or more, and further preferably 240 or more. In this embodiment, the average value is calculated from 1800 measurement data.
そして、排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から排ガス中の理論二酸化炭素濃度、及び、理論酸素濃度を算出する。
ここで、侵入空気量ＱＡｉｒは、煙突効果と湿りガス量から、以下に示す（１）式、及び、（２）式によって算出される。
Then, the theoretical carbon dioxide concentration and the theoretical oxygen concentration in the exhaust gas are calculated from the exhaust gas temperature, the auxiliary combustion gas flow rate, the fuel flow rate, and the invading air amount.
Here, the invading air amount QAir is calculated from the chimney effect and the amount of moist gas by the following equations (1) and (2).
ここで、燃料と助燃ガスとの燃焼反応は、侵入空気量を考慮すると、以下の（３）式で表すことができる。なお、（３）式において、ａは酸素比である。 Here, the combustion reaction between the fuel and the combustion assisting gas can be expressed by the following equation (3) in consideration of the amount of invading air. In equation (3), a is an oxygen ratio.
そして、排ガス中の理論二酸化濃度及び理論酸素濃度は、以下の式によって算出することができる。
理論二酸化炭素濃度＝排ガス二酸化炭素量／（乾き排ガス量＋侵入空気量）
理論酸素濃度＝（排ガス酸素量＋侵入空気量×0.21）／（乾き排ガス量＋侵入空気量）
Then, the theoretical dioxide concentration and the theoretical oxygen concentration in the exhaust gas can be calculated by the following formulas.
Theoretical carbon dioxide concentration = exhaust gas carbon dioxide amount / (dry exhaust gas amount + intrusion air amount)
Theoretical oxygen concentration = (exhaust gas oxygen amount + intrusion air amount x 0.21) / (dry exhaust gas amount + intrusion air amount)
そして、上述して得られた実測二酸化炭素濃度と理論二酸化炭素濃度、あるいは、実測酸素濃度と理論酸素濃度とを比較する。
ここで、トーピードカー内の銑鉄が溶解した際には、溶銑中の炭素と酸素が結びつき二酸化炭素を発生させる反応が生じる。これにより、図１及び図２に示すように、銑鉄が溶解した際には、実測二酸化炭素濃度が理論二酸化炭素濃度よりも高くなり、実測酸素濃度が理論酸素濃度よりも低くなる。
Then, the measured carbon dioxide concentration obtained above and the theoretical carbon dioxide concentration, or the measured oxygen concentration and the theoretical oxygen concentration are compared.
Here, when the pig iron in the torpedo car is melted, a reaction occurs in which carbon in the hot metal and oxygen are combined to generate carbon dioxide. As a result, as shown in FIGS. 1 and 2, when pig iron is dissolved, the measured carbon dioxide concentration becomes higher than the theoretical carbon dioxide concentration, and the measured oxygen concentration becomes lower than the theoretical oxygen concentration.
そこで、実測二酸化炭素濃度が理論二酸化炭素濃度よりも一定以上高くなった際に、あるいは、実測酸素濃度が理論酸素濃度よりも一定以上低くなった際に、銑鉄が溶解したと判断することが可能となる。
なお、実測二酸化炭素濃度と理論二酸化炭素濃度との差が３ｖｏｌ％以上、あるいは、実測酸素濃度と理論酸素濃度との差が３ｖｏｌ％以上になった際に、銑鉄が溶解したと判断することが好ましい。
Therefore, it is possible to determine that pig iron has melted when the measured carbon dioxide concentration is higher than the theoretical carbon dioxide concentration by a certain amount or more, or when the measured oxygen concentration is lower than the theoretical oxygen concentration by a certain amount or more. It becomes.
When the difference between the measured carbon dioxide concentration and the theoretical carbon dioxide concentration is 3 vol% or more, or the difference between the measured oxygen concentration and the theoretical oxygen concentration is 3 vol% or more, it can be determined that the iron iron has melted. preferable.
ここで、本実施形態である銑鉄の溶解処理方法においては、上述した銑鉄の溶解判定方法によって銑鉄が溶解したと判断された際に、助燃ガス流量及び燃料流量の一方又は両方を調整し、排ガス中の酸素濃度を低下させる構成としている。
銑鉄が溶解した後に、酸素濃度が高いと、溶解した銑鉄（溶銑）と酸素とが反応してスラグが多量に生成し、耐火物が劣化することになる。これを防止するために、銑鉄が溶解したと判断された時点で、排ガス中の酸素濃度を低下させることが好ましい。
Here, in the method for melting pig iron according to the present embodiment, when it is determined that the pig iron has been melted by the above-mentioned method for determining the melting of pig iron, one or both of the combustion assisting gas flow rate and the fuel flow rate are adjusted to exhaust gas. It is configured to reduce the oxygen concentration inside.
If the oxygen concentration is high after the pig iron is dissolved, the dissolved pig iron (pig iron) reacts with oxygen to generate a large amount of slag, and the refractory is deteriorated. In order to prevent this, it is preferable to reduce the oxygen concentration in the exhaust gas when it is determined that the pig iron has melted.
また、本実施形態である銑鉄の溶解量推定方法においては、上述した銑鉄の溶解判定方法によって銑鉄が溶解したと判断された時点からの経過時間に基づいて、銑鉄の溶解量を推定する構成としている。
ここで、図３に示すように、溶解したと判断した時点からの経過時間と銑鉄の溶解量とは比例関係にあり、上述した銑鉄の溶解判定方法によって銑鉄が溶解したと判断された時点からの経過時間から銑鉄の溶解量を推定することが可能となる。
Further, in the method for estimating the dissolution amount of pig iron in the present embodiment, the dissolution amount of pig iron is estimated based on the elapsed time from the time when the pig iron is determined to be dissolved by the above-mentioned method for determining the dissolution of pig iron. There is.
Here, as shown in FIG. 3, the elapsed time from the time when it is determined to be dissolved and the amount of pig iron dissolved are in a proportional relationship, and from the time when it is determined that the pig iron is dissolved by the above-mentioned method for determining the dissolution of pig iron. It is possible to estimate the amount of pig iron dissolved from the elapsed time of.
以上のような構成とされた本実施形態である銑鉄の溶解判定方法によれば、銑鉄溶解処理中に発生する排ガス中の実測二酸化炭素濃度あるいは実測酸素濃度と、排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論二酸化炭素濃度あるいは理論酸素濃度と、を比較し、実測二酸化炭素濃度が理論二酸化炭素濃度よりも一定以上高くなった際、あるいは、実測酸素濃度が理論酸素濃度よりも一定以上低くなった際に、銑鉄が溶解したと判断する構成としているので、銑鉄の溶解の有無を判定することができる。
そして、理論二酸化炭素濃度及び理論酸素濃度を算出する際に、侵入空気量を考慮していることから、トーピードカー等の開放された空間における銑鉄の溶解の有無を精度良く判定することが可能となる。
According to the iron iron dissolution determination method of the present embodiment having the above configuration, the measured carbon dioxide concentration or the measured oxygen concentration in the exhaust gas generated during the iron iron melting process, the exhaust gas temperature, the combustion assisting gas flow rate, and the fuel Comparing the theoretical carbon dioxide concentration or the theoretical oxygen concentration in the exhaust gas calculated from the flow rate and the amount of invading air, when the measured carbon dioxide concentration becomes higher than a certain level than the theoretical carbon dioxide concentration, or the measured oxygen concentration becomes Since it is determined that the iron iron is dissolved when the concentration becomes lower than the theoretical oxygen concentration by a certain level or more, it is possible to determine whether or not the iron iron is dissolved.
Since the amount of invading air is taken into consideration when calculating the theoretical carbon dioxide concentration and the theoretical oxygen concentration, it is possible to accurately determine whether or not pig iron is dissolved in an open space such as a torpedo car. ..
本実施形態である銑鉄の溶解判定方法において、実測二酸化炭素濃度が理論二酸化炭素濃度よりも３ｖｏｌ％以上高くなった時点、あるいは、実測酸素濃度が理論酸素濃度よりも３ｖｏｌ％以上低くなった時点で、銑鉄が溶解したと判断する構成とした場合には、実測二酸化炭素濃度と理論二酸化炭素濃度との間、あるいは、実測酸素濃度と理論酸素濃度との間に明確な差異が生じており、的確に銑鉄の溶解の有無を判定することが可能となる。 In the method for determining the dissolution of pig iron according to the present embodiment, when the measured carbon dioxide concentration is 3 vol% or more higher than the theoretical carbon dioxide concentration, or when the measured oxygen concentration is 3 vol% or more lower than the theoretical oxygen concentration. If it is determined that pig iron has melted, there is a clear difference between the measured carbon dioxide concentration and the theoretical carbon dioxide concentration, or between the measured oxygen concentration and the theoretical oxygen concentration. It is possible to determine the presence or absence of dissolution of pig iron.
また、本実施形態である銑鉄の溶解処理方法においては、上述した銑鉄の溶解判定方法によって銑鉄が溶解したと判断された際に、助燃ガス流量及び燃料流量の一方又は両方を調整し、排ガス中の酸素濃度を低下させる構成としているので、溶解した銑鉄（溶銑）と酸素の反応によってスラグが多量に生成することを抑制でき、耐火物の劣化を抑制することが可能となる。 Further, in the method for melting pig iron according to the present embodiment, when it is determined that the pig iron has been melted by the above-mentioned method for determining the melting of pig iron, one or both of the auxiliary fuel flow rate and the fuel flow rate are adjusted in the exhaust gas. Since it is configured to reduce the oxygen concentration of the slag, it is possible to suppress the formation of a large amount of slag due to the reaction between the dissolved pig iron (pig iron) and oxygen, and it is possible to suppress the deterioration of the refractory.
さらに、本実施形態である銑鉄の溶解量推定方法においては、上述した銑鉄の溶解判定方法によって銑鉄が溶解したと判断された時点からの経過時間に基づいて、銑鉄の溶解量を推定する構成としているので、銑鉄の溶解量（溶銑量）を精度良く推定することが可能となる。 Further, in the method for estimating the dissolution amount of pig iron according to the present embodiment, the dissolution amount of pig iron is estimated based on the elapsed time from the time when the pig iron is determined to be dissolved by the above-mentioned method for determining the dissolution of pig iron. Therefore, it is possible to accurately estimate the amount of molten pig iron (the amount of hot metal).
以上、本発明の実施形態である本実施形態である銑鉄の溶解判定方法、及び、この銑鉄の溶解判定方法を利用した銑鉄の溶解処理方法、銑鉄の溶解量推定方法について説明したが、本発明はこれに限定されることはなく、その発明の技術的思想を逸脱しない範囲で適宜変更可能である。 The method for determining the dissolution of pig iron, which is the embodiment of the present invention, the method for determining the dissolution of pig iron using the method for determining the dissolution of pig iron, and the method for estimating the amount of dissolution of pig iron have been described above. Is not limited to this, and can be appropriately changed without departing from the technical idea of the invention.
Claims (6)
排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論二酸化炭素濃度と、
を比較し、前記実測二酸化炭素濃度が前記理論二酸化炭素濃度よりも一定以上高くなった際に、前記銑鉄が溶解したと判断することを特徴とする銑鉄の溶解判定方法。 The measured carbon dioxide concentration measured by sampling the exhaust gas generated during the pig iron melting process,
The theoretical carbon dioxide concentration in the exhaust gas calculated from the exhaust gas temperature, the auxiliary gas flow rate, the fuel flow rate, and the amount of invading air,
A method for determining the dissolution of pig iron, which comprises determining that the pig iron has been dissolved when the actually measured carbon dioxide concentration becomes higher than the theoretical carbon dioxide concentration by a certain amount or more.
排ガス温度、助燃ガス流量、燃料流量及び侵入空気量から算出される排ガス中の理論酸素濃度と、
を比較し、前記実測酸素濃度が前記理論酸素濃度よりも一定以上低くなった際に、前記銑鉄が溶解したと判断することを特徴とする銑鉄の溶解判定方法。 The measured oxygen concentration measured by sampling the exhaust gas generated during the pig iron melting process,
The theoretical oxygen concentration in the exhaust gas calculated from the exhaust gas temperature, the auxiliary gas flow rate, the fuel flow rate, and the amount of invading air,
A method for determining the dissolution of pig iron, which comprises determining that the pig iron has been dissolved when the actually measured oxygen concentration is lower than the theoretical oxygen concentration by a certain amount or more.
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