JPH0324214A - Method for controlling secondary combustion rate in preliminary treatment of molten metal - Google Patents
Method for controlling secondary combustion rate in preliminary treatment of molten metalInfo
- Publication number
- JPH0324214A JPH0324214A JP16036189A JP16036189A JPH0324214A JP H0324214 A JPH0324214 A JP H0324214A JP 16036189 A JP16036189 A JP 16036189A JP 16036189 A JP16036189 A JP 16036189A JP H0324214 A JPH0324214 A JP H0324214A
- Authority
- JP
- Japan
- Prior art keywords
- oxygen
- lance
- hot metal
- secondary combustion
- metal surface
- 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.)
- Pending
Links
- 239000002184 metal Substances 0.000 title claims abstract description 56
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 56
- 238000002485 combustion reaction Methods 0.000 title claims abstract description 33
- 238000000034 method Methods 0.000 title claims description 17
- 238000011282 treatment Methods 0.000 title abstract description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 60
- 239000001301 oxygen Substances 0.000 claims abstract description 60
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 60
- 238000007664 blowing Methods 0.000 claims abstract description 18
- 238000002347 injection Methods 0.000 claims abstract description 6
- 239000007924 injection Substances 0.000 claims abstract description 6
- 238000009841 combustion method Methods 0.000 claims abstract 2
- 239000007789 gas Substances 0.000 claims description 13
- 229910000805 Pig iron Inorganic materials 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 3
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 239000000126 substance Substances 0.000 claims 1
- 229910000831 Steel Inorganic materials 0.000 abstract description 2
- 239000010959 steel Substances 0.000 abstract description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 abstract 6
- 229910052742 iron Inorganic materials 0.000 abstract 3
- 238000003723 Smelting Methods 0.000 abstract 1
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- 230000000694 effects Effects 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 239000007787 solid Substances 0.000 description 4
- 238000010586 diagram Methods 0.000 description 3
- 238000007654 immersion Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000012159 carrier gas Substances 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000008569 process Effects 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- 230000004069 differentiation Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000007704 transition Effects 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は溶銑予備処理における２次燃焼率制御方法に係
り，特に脱燐処理時等に発生するＣＯガスを有効に２次
燃焼させて、溶銑の温度降下をもたらすことなく予備処
理するための２次燃焼率制御方法に関し、製銑、製鋼分
野で広く利用される．〔従来の技術〕
近年転炉においては上底吹きの複合吹棟法が実施される
に至り、従来脱硫処理を主体として行われていた混銑車
等容器中の溶銑の予備処理は、脱炭、脱りん、脱珪処理
をも必要とされるようになり，それぞれ異なる予備処理
剤を使用して窒素もしくは乾燥空気または酸素をキャリ
アガスとして溶銑中に吹込み処理するようになり予備処
理機能の分化が進められている．
ところが、脱珪反応は発熱反応であるので、処理時間中
の溶銑温度降下量は無視できるが、脱りん反応は吸熱反
応であるので，脱りん処理中の溶銑の温度降下量は大幅
なものがある。更に説珪処理から脱りん処理へ移行時の
除滓作業による溶銑温度降下等を併せると，溶銑予備処
理による温度降下量は１５０℃以上に達し、その結果転
炉装入時の溶銑温度が１３００℃以下になることもあり
、転炉吹錬時間の延長等次工程でのコスト増を生じてい
る．
従来、上記溶銑の温度降下の問題を解決するため、第４
図に示すようにランス６を用いたフラツクス噴射による
脱りん処理を行いながら、混銑車２の炉口８から上吹き
ランス１０によって酸素を供給し、脱りんに伴ない発生
したＣＯガスを燃焼させたり、また特開昭５９−８９７
１０にて開示されたような２重管構造の浸漬ランスを使
用して酸素をキャリアガスとしてフラツクスを溶銑４中
に吹込み、溶銑中のＣと反応させ、その反応熱により溶
銑の温度降下を防止する方法がとられている。[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a secondary combustion rate control method in hot metal pretreatment, and in particular, to effectively secondary combustion of CO gas generated during dephosphorization treatment, etc. This method relates to a secondary combustion rate control method for pre-treating hot metal without causing a temperature drop, and is widely used in the ironmaking and steelmaking fields. [Prior art] In recent years, the combined blowing ridge method of top and bottom blowing has been implemented in converters, and the preliminary treatment of hot metal in containers such as pig iron mixers, which used to be mainly desulfurization treatment, has been replaced by decarburization, Dephosphorization and desiliconization treatments also became necessary, and different pretreatment agents were used to inject nitrogen, dry air, or oxygen into the hot metal as a carrier gas, leading to the differentiation of pretreatment functions. is in progress. However, since the desiliconization reaction is an exothermic reaction, the drop in temperature of the hot metal during the treatment time can be ignored, but since the dephosphorization reaction is an endothermic reaction, the drop in temperature of the hot metal during the dephosphorization process is significant. be. Furthermore, when adding in the drop in hot metal temperature due to slag removal work during the transition from silica treatment to dephosphorization, the temperature drop due to hot metal pretreatment reaches over 150°C, and as a result, the hot metal temperature at the time of charging into the converter reaches 1300°C. ℃ or lower, resulting in increased costs in subsequent processes such as extended converter blowing time. Conventionally, in order to solve the problem of the temperature drop of hot metal, a fourth
As shown in the figure, while performing dephosphorization treatment by flux injection using a lance 6, oxygen is supplied from the furnace port 8 of the pig iron mixer car 2 by an upward blowing lance 10, and CO gas generated due to dephosphorization is combusted. Also, Japanese Patent Publication No. 59-897
Using a double-tube structure immersion lance as disclosed in No. 10, flux is blown into the hot metal 4 using oxygen as a carrier gas, and is reacted with C in the hot metal, causing the temperature of the hot metal to drop by the heat of reaction. Measures are being taken to prevent this.
しかしながら第４図の上吹きランス１０による場合には
、溶銑４の表面は、スラグ１２によって覆われているほ
か、酸素１４と溶銑４との直接反応による反応熱も混銑
車２に収容された溶銑４中の表層部のみに限られ、温度
上昇効果は余り多くを期待することができない。また、
特開昭５９−８９７１０によって開示された浸漬ランス
を使用する場合も、ランスの浸漬深さを著しく大とする
ことが困難であるので、溶銑４の表層部のみの昇熱に限
られるおそれがある。更に炉中で発生したＣＯと０２と
の反応による２次燃焼熱も、従来２次燃焼率の制御方法
が開発されていないために、溶銑４への着熱効果は極め
て低いものであった。However, in the case of using the top-blowing lance 10 in FIG. 4, and the temperature increase effect is not expected to be much. Also,
Even when using the immersion lance disclosed in JP-A-59-89710, it is difficult to significantly increase the immersion depth of the lance, so there is a risk that the heating will be limited to only the surface layer of the hot metal 4. . Furthermore, the heat of secondary combustion caused by the reaction between CO and 02 generated in the furnace has an extremely low heat transfer effect on the hot metal 4 because no method for controlling the rate of secondary combustion has been developed.
かくの如く，従来の溶銑予備処理における溶銑の温度補
償技術は、未だ十分開発されていなかったが，次の２つ
に大別される．
（ａ） 特開昭５８−１６００８に開示されている如
く，予備処理における酸素源としてのミルスケール、酸
化鉄等の固体酸素を気体酸素で代替し、固体酸素の顕熱
に相当する熱量を節約し利用する方法。As described above, the hot metal temperature compensation technology in conventional hot metal pretreatment has not yet been fully developed, but it can be broadly divided into the following two types. (a) As disclosed in JP-A-58-16008, solid oxygen such as mill scale or iron oxide as an oxygen source in pretreatment is replaced with gaseous oxygen to save the amount of heat equivalent to the sensible heat of solid oxygen. How to use it.
（ｂ） 特開昭６３−１８０３４５に開示されている
如く、気体酸素を溶銑表面に上吹きし、脱りん時等に発
生するＣＯガスを容器内で２次燃焼させる方法。(b) As disclosed in JP-A No. 63-180345, a method in which gaseous oxygen is blown upward onto the surface of hot metal and CO gas generated during dephosphorization is secondary-combusted in a container.
しかしながら上記２方法には一長一短があるので、予備
処理前の溶銑温度、溶銑或分等によって、上記（ａ）、
（ｂ）２方法を使い分けするか、もしくは併せて実施す
る必要がある。そのために２次燃焼における燃焼効率を
知る有効な方法が是非必要である。However, the above two methods have advantages and disadvantages, so depending on the temperature of the hot metal before pretreatment, the amount of hot metal, etc., the above (a),
(b) It is necessary to use the two methods separately or to implement them together. For this reason, an effective method for determining combustion efficiency in secondary combustion is absolutely necessary.
本発明の目的は、溶銑予備処理における上記溶銑温度を
補償する２方法のうち、酸化鉄等の固体酸素を気体酸素
に代替させる熱補償量と、２次燃焼による熱補償量との
比率を制御するに必要な気体酸素による発生ＣＯガスの
２次燃焼効率を求める方法を提供するにある。The purpose of the present invention is to control the ratio of the heat compensation amount by substituting solid oxygen such as iron oxide with gaseous oxygen and the heat compensation amount by secondary combustion among the two methods of compensating the hot metal temperature in hot metal pretreatment. The object of the present invention is to provide a method for determining the secondary combustion efficiency of generated CO gas using gaseous oxygen necessary for the combustion of CO gas.
本発明の要旨とするところは次の如くである。 The gist of the present invention is as follows.
すなわち、混銑車等容器に収容された溶銑に上吹きラン
スを用いて酸素を単独もしくは予備処理剤と共に吹込み
発生するＣＯガスの２次燃焼により該溶銑を昇熱させる
溶銑予備処理における２次燃焼方法において、前記上吹
きランスの高さ、ランス直径、ランス出口部における酸
素吹出し速度のうちの少くとも１つの要素を変化させる
ことにより下記（１）式にて前記溶銑湯面に到達する酸
素流速度を求め，
α′ｄｅ１ＣＯＳψ●■ｅ
Ｖｍ＝ ・・・・
・・ （１）ｈ
ここに Ｖｍ：＠素の溶銑湯面到達速度（ｍ／ｓｅｅ）
ｖｅ：酸素のランス出口速度（ｍ／ｓｅｅ）ｄｅ：ラン
ス出口部直径（ａｌ）
ψ：ランス噴射角度（度）
ｈ：ランス高さ（．）
α：係数
前記酸素の溶銑湯面到達速度を変化させることにより下
記Ｘ−Ｙ座標にて表わされるＡ曲線から前記吹込み気体
酸素による２次燃焼効率を制御することを特徴とする溶
銑予備処理における２次燃焼率制御方法。In other words, secondary combustion in hot metal pretreatment involves blowing oxygen alone or together with a pretreatment agent into hot metal stored in a container such as a pig iron mixer using a top-blowing lance, and raising the temperature of the hot metal through secondary combustion of the generated CO gas. In the method, by changing at least one element among the height of the top blowing lance, the lance diameter, and the oxygen blowing speed at the lance outlet, the oxygen flow reaching the hot metal surface is determined by the following formula (1). Find the speed, α′de1COSψ●■e Vm= ・・・
... (1) h where Vm: @ speed of reaching the hot metal surface (m/see)
ve: Oxygen lance exit velocity (m/see) de: Lance exit diameter (al) ψ: Lance injection angle (degrees) h: Lance height (.) α: Coefficient Change the speed at which the oxygen reaches the hot metal surface A secondary combustion rate control method in hot metal pretreatment, characterized in that the secondary combustion efficiency by the blown gas oxygen is controlled from the A curve represented by the following X-Y coordinates by:
記
Ｘ軸：酸素の溶銑湯面到達速度（ ｍ ／ｓｅｃ）Ｙ軸
：気体酸素の２次燃焼効率（％）
Ａ曲線座標：
本発明者らは、溶銑予備処理における気体酸素を上吹き
する実験において、上吹きランスの高さ、ランスの直径
．ランス出口部における酸素吹出し速度を変化させるこ
とにより発生Ｃ○の２次燃焼率が変化することに着目し
、実験、研究の結果本発明を得るに至った。X-axis: velocity of oxygen reaching the hot metal surface (m/sec) Y-axis: secondary combustion efficiency of gaseous oxygen (%) A-curve coordinates: The present inventors conducted an experiment in which gaseous oxygen was top-blown in hot metal pretreatment. , the height of the top-blown lance, and the diameter of the lance. We focused on the fact that the secondary combustion rate of generated C○ changes by changing the oxygen blowing speed at the lance outlet, and as a result of experiments and research, we have arrived at the present invention.
通常溶銑予備処理に使用する内径が変化のない第１図に
示す如き直線状ランスにおいては、次の（１）式の関係
が成立する．すなわち、Ｖｍ：酸素の溶銑湯面到達速度
（ｍ／ｓｅｅ）ｖｅ：酸素のランス出口速度（ｍ／ｓｅ
ｅ）ｄｅ：ランス出口部直径（■）
ψ：ランス噴射角度（度）
ｈ：ランス高さ（Ｃｌｌ）
α：係数
と、すれば，
ｈ
なお、ψ：ランス噴射角度は第１図に示す如くランス６
の中心軸と溶銑４の平面上の垂直線との角度である．ま
た、係数αはランス６の形状等により異なるも第１図に
示す如きストレートノズルの場合は通常６．３である．
しかして、本発明者らの実験によれば、酸素の溶銑湯面
到達速度Ｖｍ （ｍ／ｓａｃ）と，発生ＣＯの気体酸素
による２次燃焼効率との間には、第２図に示す如き相関
があることを見出した。すなわち、第２図は次のＸ−Ｙ
座標にて表わされるＡ曲線として示される。In a linear lance as shown in Fig. 1, which is normally used for hot metal pretreatment and whose inner diameter does not change, the following relationship (1) holds true. That is, Vm: velocity of oxygen reaching the hot metal surface (m/see) ve: velocity of oxygen at the lance outlet (m/see)
e) de: lance outlet diameter (■) ψ: lance injection angle (degrees) h: lance height (Cll) α: coefficient, then, h Note that ψ: lance injection angle is as shown in Figure 1. Lance 6
is the angle between the central axis of and the vertical line on the plane of hot metal 4. Although the coefficient α varies depending on the shape of the lance 6, etc., it is usually 6.3 in the case of a straight nozzle as shown in FIG. According to the experiments conducted by the present inventors, there is a difference between the velocity of oxygen reaching the hot metal surface Vm (m/sac) and the secondary combustion efficiency of generated CO by gaseous oxygen, as shown in Fig. 2. We found that there is a correlation. In other words, Figure 2 shows the following X-Y
It is shown as an A curve expressed in coordinates.
Ｘ軸：酸素の溶銑湯面到達速度（ｍ／ｓｅｅ）Ｙ軸：気
体酸素の２次燃焼効率（％）
Ａ曲線座＃Ａ＝
〔実施例〕
本発明者らは、内径３２ｎｍおよび２０ｆｆｉのストレ
ートノズルを使用して２５０ｔ混銑車において，上記（
１）式によって求められる酸素の湯面到達速度を変化さ
せ、すなわち、ランスの高さ，ランスの直径、気体酸素
のランス出口速度を種々変化させて、酸素の溶銑湯面到
達速度（ ｍ ／ｓａｃ）を変化させ、これに対応する
気体酸素の２次燃焼効率を実測した結果は第３図に示す
とおりである。第３図において、０印は３２閣φストレ
ートノズルによった結果であり，●印は、２０ｗｓφス
トレートノズルによった結果である。すなわち、Ｘ軸の
酸素の湯面到達速度（ｍ／ｓｅｃ）とＹ軸の気体酸素に
よる２次燃焼効率との間の相関は、ほぼＡ曲線にて表わ
される．第２図にて示されるＡ曲線はかくの如くして本
発明者らの実験結果から得られたものである。X-axis: velocity of oxygen reaching the hot metal surface (m/see) Y-axis: secondary combustion efficiency of gaseous oxygen (%) The above (
1) By changing the velocity of oxygen reaching the hot metal surface determined by the formula, that is, by varying the lance height, lance diameter, and lance outlet velocity of gaseous oxygen, the oxygen velocity reaching the hot metal surface (m/sac ) and measured the corresponding secondary combustion efficiency of gaseous oxygen, as shown in Fig. 3. In FIG. 3, the 0 mark is the result using a 32 mm diameter straight nozzle, and the ● mark is the result using a 20 ws diameter straight nozzle. That is, the correlation between the velocity of oxygen reaching the hot water level (m/sec) on the X-axis and the secondary combustion efficiency by gaseous oxygen on the Y-axis is approximately expressed by the A curve. The A curve shown in FIG. 2 was thus obtained from the experimental results of the present inventors.
本発明はランスにおける酸素の場面到達速度（ ｍ ／
ｓｅｅ）を（１）式にて表わされる理論式から求め、求
められた酸素の場面到達速度と気体酸素による発生ＣＯ
ガスの２次燃焼効率との相関を実験より求めた第２図八
曲線にて表わされることを見出したものであって、これ
によって次の効果を挙げることができた。The present invention is characterized by the speed at which oxygen reaches the scene in the lance (m/
See) is calculated from the theoretical equation expressed by equation (1), and the obtained oxygen arrival velocity and the CO generated by gaseous oxygen are
It was discovered that the correlation with the secondary combustion efficiency of gas is expressed by the eight curves in Figure 2, which were obtained through experiments, and the following effects could be achieved by this.
（イ） 気体酸素の上吹き速度（Ｎｒｎ’／ｗｉｎ）か
ら求められる気体酸素のランス出口速度（ｍ／ｓｅｅ）
およびランスの出口部直径、ランス高さの３者のうち、
少くとも１つの要素を変化させることによつて上記（１
）式より求められる気体酸素の場面到達速度を制御する
ことにより、第２図八曲線にて表わされる気体酸素によ
る発生ＣＯガスの２次燃焼効率を任意に制御することが
できるようになった。(b) Lance exit velocity of gaseous oxygen (m/see) determined from the top blowing velocity of gaseous oxygen (Nrn'/win)
Out of the three factors, the exit diameter of the lance, and the height of the lance,
By changing at least one element, the above (1
) By controlling the speed at which gaseous oxygen reaches the scene, which is determined by the equation (2), it has become possible to arbitrarily control the secondary combustion efficiency of the generated CO gas by gaseous oxygen, which is represented by the eight curves in FIG.
（口） （イ）の結果から溶銑予備処理における溶銑温
度補償において、酸化鉄等の固体酸素を気体酸素に代替
することによる熱補償量と、発坐ＣＯガスの２次燃焼に
よる熱補償量の比率を任意に制御することができるよう
になった。(Example) From the results of (a), in hot metal temperature compensation in hot metal pretreatment, the amount of heat compensation by replacing solid oxygen such as iron oxide with gaseous oxygen, and the amount of heat compensation by secondary combustion of sitting CO gas. The ratio can now be controlled arbitrarily.
（ハ） （イ）、（ロ）の結果、溶銑予備処理における
温度降下を最少限に抑制して１３００℃以上の高温の予
備処理溶銑を転炉に供給することができ、転炉吹錬時間
の短縮による鋼溶製コストの低減に貢献することができ
た．(c) As a result of (a) and (b), it is possible to minimize the temperature drop during hot metal pretreatment and supply pretreated hot metal at a high temperature of 1300°C or higher to the converter, and the converter blowing time is This contributed to reducing steel melting costs by shortening the time.
第１図は溶銑予備処理に使用するストレートノズルを有
するランスの上記（１）式中の記号を説明する模式図、
第２図は本発明における酸素の場面到達速度（ｍ／ｓｅ
ｅ）と気体酸素によるＣＯガスの２次燃焼効率（％）と
の相関図，第３図は本発明の実施例における第２図と同
様の相関図、第４図は混銑車における溶銑予備処理の従
来法を示す模式断面図である。
２・・・混銑車 ４・・・溶銑６・・・ラン
ス ８・・・炉口１０・・・酸素上吹きラン
スFIG. 1 is a schematic diagram explaining the symbols in the above formula (1) of a lance with a straight nozzle used for hot metal pretreatment;
Figure 2 shows the oxygen arrival velocity (m/se) in the present invention.
e) and the secondary combustion efficiency (%) of CO gas using gaseous oxygen. Figure 3 is a correlation diagram similar to Figure 2 in the embodiment of the present invention. Figure 4 is a diagram showing hot metal pretreatment in a pig iron mixing car. FIG. 2 is a schematic cross-sectional view showing a conventional method. 2... Pig mixer car 4... Hot metal 6... Lance 8... Furnace mouth 10... Oxygen top blowing lance
Claims (1)
用いて酸素を単独もしくは予備処理剤と共に吹込み発生
するＣＯガスの２次燃焼により該溶銑を昇熱させる溶銑
予備処理における２次燃焼方法において、前記上吹きラ
ンスの高さ、ランス直径、ランス出口部における酸素吹
出し速度のうちの少くとも１つの要素を変化させること
により下記（１）式にて前記溶銑湯面に到達する酸素流
速度を求め、 Ｖｍ＝α・ｄｅ・ｃｏｓφ・Ｖｅ／ｈ・・・・・・（１
）ここにＶｍ：酸素の溶銑湯面到達速度（ｍ／ｓｅｃ）
Ｖｅ：酸素のランス出口速度（ｍ／ｓｅｃ）ｄｅ：ラン
ス出口部直径（ｃｍ） ψ：ランス噴射角度（度） ｈ：ランス高さ（ｃｍ） α：係数 前記酸素の溶銑湯面到達速度を変化させることにより下
記Ｘ−Ｙ座標にて表わされるＡ曲線から前記吹込み気体
酸素による２次燃焼効率を制御することを特徴とする溶
銑予備処理における２次燃焼率制御方法。 記 Ｘ軸：酸素の溶銑湯面到達速度（ｍ／ｓｅｃ）Ｙ軸：気
体酸素の２次燃焼効率（％） Ａ曲線座標：▲数式、化学式、表等があります▼(1) Secondary in hot metal pretreatment, in which oxygen is blown alone or together with a pretreatment agent into hot metal stored in a container such as a pig iron mixer using a top-blowing lance, and the temperature of the hot metal is raised by secondary combustion of the generated CO gas. In the combustion method, by changing at least one element among the height of the top blowing lance, the diameter of the lance, and the oxygen blowing speed at the lance outlet, the oxygen reaching the hot metal surface is determined by the following formula (1). Find the flow velocity, Vm=α・de・cosφ・Ve/h...(1
) where Vm: velocity of oxygen reaching the hot metal surface (m/sec)
Ve: Oxygen lance exit velocity (m/sec) de: Lance exit diameter (cm) ψ: Lance injection angle (degrees) h: Lance height (cm) α: Coefficient to change the speed at which the oxygen reaches the hot metal surface A secondary combustion rate control method in hot metal pretreatment, characterized in that the secondary combustion efficiency by the blown gas oxygen is controlled from the A curve represented by the following X-Y coordinates by: X-axis: Speed of oxygen reaching the hot metal surface (m/sec) Y-axis: Secondary combustion efficiency of gaseous oxygen (%) A-curve coordinates: ▲Mathematical formulas, chemical formulas, tables, etc. are included▼
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16036189A JPH0324214A (en) | 1989-06-22 | 1989-06-22 | Method for controlling secondary combustion rate in preliminary treatment of molten metal |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16036189A JPH0324214A (en) | 1989-06-22 | 1989-06-22 | Method for controlling secondary combustion rate in preliminary treatment of molten metal |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0324214A true JPH0324214A (en) | 1991-02-01 |
Family
ID=15713313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16036189A Pending JPH0324214A (en) | 1989-06-22 | 1989-06-22 | Method for controlling secondary combustion rate in preliminary treatment of molten metal |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0324214A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013028832A (en) * | 2011-07-27 | 2013-02-07 | Jfe Steel Corp | Molten iron refining method |
-
1989
- 1989-06-22 JP JP16036189A patent/JPH0324214A/en active Pending
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2013028832A (en) * | 2011-07-27 | 2013-02-07 | Jfe Steel Corp | Molten iron refining method |
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