JPS635448B2 - - Google Patents
Info
- Publication number
- JPS635448B2 JPS635448B2 JP56033549A JP3354981A JPS635448B2 JP S635448 B2 JPS635448 B2 JP S635448B2 JP 56033549 A JP56033549 A JP 56033549A JP 3354981 A JP3354981 A JP 3354981A JP S635448 B2 JPS635448 B2 JP S635448B2
- Authority
- JP
- Japan
- Prior art keywords
- carbon dioxide
- lower nozzle
- oxygen
- blown
- pine
- 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
Links
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 78
- 239000001569 carbon dioxide Substances 0.000 claims description 39
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 39
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 29
- 239000001301 oxygen Substances 0.000 claims description 29
- 229910052760 oxygen Inorganic materials 0.000 claims description 29
- 238000007664 blowing Methods 0.000 claims description 27
- 235000008331 Pinus X rigitaeda Nutrition 0.000 claims description 25
- 235000011613 Pinus brutia Nutrition 0.000 claims description 25
- 241000018646 Pinus brutia Species 0.000 claims description 25
- 238000000034 method Methods 0.000 claims description 12
- 238000009423 ventilation Methods 0.000 claims description 12
- 238000007670 refining Methods 0.000 claims description 10
- 229910052799 carbon Inorganic materials 0.000 claims description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 238000003723 Smelting Methods 0.000 claims 1
- 239000007789 gas Substances 0.000 description 19
- 229910052751 metal Inorganic materials 0.000 description 11
- 239000002184 metal Substances 0.000 description 11
- 238000010586 diagram Methods 0.000 description 7
- 239000000203 mixture Substances 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 3
- 229910000831 Steel Inorganic materials 0.000 description 3
- 229910002091 carbon monoxide Inorganic materials 0.000 description 3
- 239000010959 steel Substances 0.000 description 3
- 238000003756 stirring Methods 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 239000011449 brick Substances 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000009826 distribution Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000004215 Carbon black (E152) Substances 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 239000001307 helium Substances 0.000 description 1
- 229910052734 helium Inorganic materials 0.000 description 1
- SWQJXJOGLNCZEY-UHFFFAOYSA-N helium atom Chemical compound [He] SWQJXJOGLNCZEY-UHFFFAOYSA-N 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 238000005259 measurement 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
- 239000011819 refractory material Substances 0.000 description 1
- -1 steam Chemical class 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/30—Regulating or controlling the blowing
- C21C5/35—Blowing from above and through the bath
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
Description
【発明の詳細な説明】
本発明は上ノズル（上ランス）から酸素を、下
ノズル（底吹羽口）から二酸化炭素を吹込む上下
吹転炉における精錬方法に関し、その目的は溶湯
撹拌反応を活発化し、介在物や不純物がすくなく
かつ所望の成分を有する溶鋼を得ることにあり、
さらに他の目的は下ノズルの閉塞を効果的に予防
し安定した吹錬を継続できる手段を提供すること
にあり、さらにその他の目的は二酸化炭素の有効
燃料化を計る手段を提供することにある。Detailed Description of the Invention The present invention relates to a refining method in a top-bottom blowing converter in which oxygen is blown from an upper nozzle (upper lance) and carbon dioxide is blown from a lower nozzle (bottom blowing tuyere), and its purpose is to achieve a molten metal stirring reaction. The objective is to obtain molten steel that is activated, has few inclusions and impurities, and has the desired composition.
Still another purpose is to provide a means to effectively prevent blockage of the lower nozzle and continue stable blowing, and still another purpose is to provide a means to effectively convert carbon dioxide into fuel. .
近時酸素転炉において上ノズルを用いてO2を、
下ノズルを用いてたとえばアルゴン，ヘリウム，
水素，窒素，一酸化炭素，二酸化炭素，蒸気，炭
化水素ガスのうちの１種もしくは２種以上を吹込
むか、あるいはそれらとO2を混合して吹込む手
段が試みられている。 Recently, in oxygen converter, O 2 is introduced using the upper nozzle.
For example, argon, helium,
Attempts have been made to inject one or more of hydrogen, nitrogen, carbon monoxide, carbon dioxide, steam, and hydrocarbon gases, or to inject a mixture of these and O 2 .
本発明者等は上ノズルからO2を、下ノズルか
らCO2を吹込む酸素転炉精錬方法を研究した結
果、特に下ノズルからのCO2吹込み方法には改良
すべき点のあることを知つた。 As a result of research into an oxygen converter refining method in which O 2 is injected from the upper nozzle and CO 2 from the lower nozzle, the present inventors found that there are points that need to be improved, especially in the method of injecting CO 2 from the lower nozzle. I knew.
第１図ａは転炉の底部耐火物１に嵌着された単
管の下ノズル２から矢印３の如く二酸化炭素と酸
素の混合ガスを溶湯４内に吹込んで精錬を行なう
際の部分断面概要図で、下ノズル２の開口部の直
上の溶湯４内には凝固もしくは半凝固状態の茸形
構造物（これをマツシユルームと言う）が出来
て、そのマツシユルーム５の通気孔６を介してガ
スが吹込まれることが判明しているが、前記マツ
シユルーム５は第１図ｂに示すように精錬状況に
よつてその形態が崩れ、通気孔６が閉塞状態とな
つてガスの吹込みが不可能となる場合が生ずる。
このため混合ガス中の酸素量を高めるとマツシユ
ルーム５自体が溶解して無くなり、溶湯４が直接
下ノズル２と接触しその溶損を早め結果として精
錬が効果的に遂行できないと言う問題点が生ず
る。即ちこの手段では制御はきわめて難しい。 Figure 1a is a partial cross-sectional view of refining by blowing a mixed gas of carbon dioxide and oxygen into the molten metal 4 as shown by the arrow 3 from the lower nozzle 2 of the single tube fitted into the bottom refractory 1 of the converter. In the figure, a solidified or semi-solidified mushroom-shaped structure (this is called a pine room) is formed in the molten metal 4 directly above the opening of the lower nozzle 2, and gas flows through the vent hole 6 of the pine room 5. However, as shown in Figure 1b, the shape of the pine room 5 collapses due to the refining conditions, and the vent hole 6 becomes blocked, making it impossible to inject gas. There are cases where this happens.
For this reason, if the amount of oxygen in the mixed gas is increased, the pine room 5 itself will melt and disappear, causing the problem that the molten metal 4 will come into direct contact with the lower nozzle 2, accelerating its melting and as a result, refining cannot be carried out effectively. . That is, control is extremely difficult with this method.
第２図ａは下ノズル２ａを外筒７と内筒８を組
合せた同心二重管構造とし、外筒７、内筒８から
二酸化炭素を吹込み精錬を行なう際の部分断面概
要図で、矢印９は外筒７を通つて吹込まれる二酸
化炭素で矢印１０は内筒８を通つて吹込まれる二
酸化炭素である。このようにするとマツシユルー
ム５内に通気孔６とは別に細い通気孔１１が多数
発生して二酸化炭素は該細い通気孔１１と内管８
に連通する中央部の大きい通気孔６を介して溶湯
４内に吹込まれる。第２図の例では内，外管７，
８を通る二酸化炭素の圧力および量を相対的に変
化させることが出来る。即ち水平断面で見た場合
第３図に示す通り下ノズルの周面における流速分
布の制御が第４図、第５図の如く可能になるた
め、第１図ａの例に比較して精錬はより効果的に
なる。第４図、第５図で曲線Ａ，Ｂは流速分布を
示す。而して精錬状況によつては第２図ｂに示す
ようにマツシユルーム５がつぶれて通気孔６は閉
塞し、吹込まれた二酸化炭素は矢印１２に示すよ
うにマツシユルーム５の最下端から噴出するよう
になりマツシユルーム５の消失や変形を来たすの
みならず耐火物の溶損が進んでさらに撹拌作用の
効果は、低下する例が生じた。 Fig. 2a is a partial cross-sectional schematic diagram of the lower nozzle 2a having a concentric double pipe structure combining an outer cylinder 7 and an inner cylinder 8, and performing refining by blowing carbon dioxide from the outer cylinder 7 and the inner cylinder 8. Arrow 9 indicates carbon dioxide blown through the outer cylinder 7, and arrow 10 indicates carbon dioxide blown through the inner cylinder 8. In this way, a large number of thin ventilation holes 11 are generated in the pine room 5 in addition to the ventilation holes 6, and carbon dioxide flows through the thin ventilation holes 11 and the inner pipe 8.
It is blown into the molten metal 4 through a large vent hole 6 in the center that communicates with the molten metal 4. In the example shown in Fig. 2, the inner and outer tubes 7,
The relative pressure and amount of carbon dioxide passing through 8 can be varied. That is, when viewed in horizontal section, as shown in Fig. 3, it becomes possible to control the flow velocity distribution on the circumferential surface of the lower nozzle as shown in Figs. Become more effective. In FIGS. 4 and 5, curves A and B show flow velocity distributions. Depending on the refining situation, the pine room 5 collapses and the ventilation hole 6 is blocked as shown in FIG. In some cases, this not only caused the pine room 5 to disappear or deform, but also caused the refractory to melt and deteriorate, further reducing the effectiveness of the stirring action.
そこで本発明者等は第６図に示す通り下ノズル
を外筒７と内筒８からなる同心二重管構造とし該
外筒７、内筒８に二酸化炭素供給管７０，８０を
接続して底吹きを行なうに当り酸素供給管１４を
前記内筒８に通ずる二酸化炭素供給管８０に接続
し、該酸素供給管からマツシユルーム通気孔保持
用酸素を適宜添加することによりマツシユルーム
を常時適正に維持せしめることにより吹錬を円滑
に行なうことに成功した。 Therefore, the present inventors made the lower nozzle a concentric double pipe structure consisting of an outer cylinder 7 and an inner cylinder 8, as shown in FIG. 6, and connected carbon dioxide supply pipes 70 and 80 to the outer cylinder 7 and inner cylinder 8. When performing bottom blowing, the oxygen supply pipe 14 is connected to the carbon dioxide supply pipe 80 leading to the inner cylinder 8, and oxygen for maintaining the pine room ventilation hole is appropriately added from the oxygen supply pipe to maintain the pine room properly at all times. As a result, we succeeded in conducting the blowing process smoothly.
第６図において１５，１６，１７は圧力計、１
８，１９，２０は制御弁、２１，２２，２３は流
量計、２４はガス流制御装置であり、２５は酸素
供給用上ノズルで２６は転炉炉体、２７は溶湯を
示す。 In Fig. 6, 15, 16, 17 are pressure gauges, 1
8, 19, and 20 are control valves, 21, 22, and 23 are flow meters, 24 is a gas flow control device, 25 is an upper nozzle for oxygen supply, 26 is a converter furnace body, and 27 is a molten metal.
第７図は第６図の装置を用いて下ノズル２ａか
ら二酸化炭素を吹込む際のマツシユルーム５の概
念図（マツシユルームは直接目視できないが、種
種の模凝テストや実測によりその存在は推認でき
る）であり、内筒８から吹込まれる二酸化炭素に
酸素ガスが適切に添加される場合、マツシユルー
ム５および通気孔６は適正な形状を保持し、二酸
化炭素の精錬に必要な所望量を吹込むことができ
る。而して吹錬状況の変化によつてマツシユルー
ム５は絶えず変化するため、前述の通り添加する
酸素量はそれに応じて制御される必要がある。た
とえば時としてマツシユルーム５が消失するよう
な場合は酸素の添加を中断したり、前記通気孔６
が閉塞しそうな場合は酸素添加量を多くする必要
がある。 FIG. 7 is a conceptual diagram of the pine room 5 when carbon dioxide is blown from the lower nozzle 2a using the device shown in FIG. When oxygen gas is appropriately added to the carbon dioxide blown from the inner cylinder 8, the pine room 5 and the ventilation hole 6 maintain their proper shapes, and the desired amount necessary for refining carbon dioxide can be blown. Can be done. Since the pine room 5 constantly changes as the blowing conditions change, the amount of oxygen added needs to be controlled accordingly as described above. For example, if the pine room 5 sometimes disappears, the addition of oxygen may be interrupted or the ventilation hole 6 may be removed.
If there is a possibility of blockage, it is necessary to increase the amount of oxygen added.
本発明者等の研究によれば添加すべき酸素量は
０〜30％の範囲が望ましく、その理由は次の通り
である。 According to research by the present inventors, the amount of oxygen to be added is preferably in the range of 0 to 30%, and the reason is as follows.
即ち二酸化炭素CO2による吸熱量と酸素O2によ
る発熱量がバランスする点は（O2／CO2≒0.1）
であり、通常O210％添加を中心として添加量を
加減する。つまり積極的に発熱させて通気状況を
改善する場合は10％〜30％を添加し、逆にマツシ
ユルームの形成を促進したい場合は０〜10％の添
加量において加減する。O230％以上の添加は、
マツシユルームの消失を来たしやすい傾向が認め
られそれ以上の添加は目的に対し不経済となる。
又特に新しいノズルの使用時ではマツシユルーム
の形成を急ぐためO2の添加は行なわずCO2のみを
吹込むことが望ましい。 In other words, the point where the amount of heat absorbed by carbon dioxide CO 2 and the amount of heat generated by oxygen O 2 are balanced is (O 2 /CO 2 ≒ 0.1).
The amount of O 2 added is usually adjusted around 10%. In other words, if you want to actively generate heat and improve the ventilation situation, add 10% to 30%, and conversely, if you want to promote the formation of pine room, add 0 to 10%. Addition of 30% or more O 2
There is a tendency for the pine room to disappear, and adding more than that is uneconomical for the purpose.
In addition, especially when using a new nozzle, it is desirable to blow only CO 2 without adding O 2 in order to hasten the formation of a pine room.
次に下ノズル２ａによる吹込みが適切に行なわ
れているか否かは吹込まれる二酸化炭素の吹込み
圧力と流量を検出することによつて知ることがで
きる。 Next, whether or not the blowing by the lower nozzle 2a is being performed appropriately can be determined by detecting the blowing pressure and flow rate of the carbon dioxide being blown into the carbon dioxide.
第８図は下ノズル２ａを取付け内管８について
吹錬を行なわない前に供給される二酸化炭素の圧
力（Kg／cm2Ｇ）の流量（Ｎm3／Hr）の関係を調
査すると共に、下ノズル２ａの閉塞によつて該圧
力Ｐと流量Ｑが変化する割合を調査したグラフで
あり、曲線２８〜３６はその変化割合を下ノズル
の断面開孔率（％）で捉えたもので、たとえば曲
線２８は閉塞のない状態つまり断面開孔率
（マツシユルーム通気孔の断面積／新しい下ノズル内管
断面積）100％の場合
のＰ，Ｑの値の例で、曲線３６は断面開孔率20％
の際のＰ，Ｑの値を示す例であり、これらは下ノ
ズルの寸法，形状，二酸化炭素の供給圧力等のパ
ラメーターの変化に応じて適宜実測試験や計算に
よつて求めることが出来る。 Figure 8 shows the relationship between the pressure (Kg/cm 2 G) and flow rate (Nm 3 /Hr) of carbon dioxide supplied before installing the lower nozzle 2a and not blowing the inner pipe 8. This is a graph investigating the rate at which the pressure P and flow rate Q change due to the blockage of the nozzle 2a.Curves 28 to 36 are graphs that capture the rate of change in terms of the cross-sectional opening ratio (%) of the lower nozzle. Curve 28 is an example of the values of P and Q when there is no blockage, that is, the cross-sectional porosity (cross-sectional area of the pine room ventilation hole/cross-sectional area of the new lower nozzle inner pipe) is 100%, and curve 36 is the cross-sectional porosity of 20. %
This is an example showing the values of P and Q in the case of the above, and these can be determined by actual measurement tests or calculations as appropriate depending on changes in parameters such as the size and shape of the lower nozzle and the supply pressure of carbon dioxide.
第９図は、前記Ｐ，Ｑの関係を用いて前記ガス
流制御装置２４で行なわれる制御要領を示すブロ
ツク線図で、前記圧力計１６および流量計２２か
らの一定時間毎、もしくは連続的な入力信号にも
とづいて、あらかじめ求められている開孔率毎の
PQ線図から下ノズルの開孔率計算が行なわれ、
それが所望の基準開孔率に適合し、外管７からの
吹込量とあわせて所望の流量が確保されていれば
そのまま二酸化炭素の吹込みが実施される。この
場合外管７の出口の流速を特定速度以上に保ち、
内管８の流量を変化させるか、あるいは内管流量
に対する外管流量の割合を変化させる方法、さら
には内管の流量を一定に保ち、外管の流量を変化
させる方法など適宜採用してマツシユルームの良
好な形状を保持させることも可能ではあるが、こ
のような制御では良好な形状が保持できない吹錬
が多いのでその場合には内管８の二酸化炭素に添
加すべき酸素量を前述のように二酸化炭素の０〜
30％の範囲として常時添加すると非常に良い結果
が得られる。又、内管の圧力が高くなり流量が減
じた場合ガス流制御装置２４において、所望の下
ノズル開孔率が得られるように添加すべき酸素量
の演算が行なわれ制御弁２０の操作指令が出され
る。前記演算は過去の吹錬実績およびもしくは反
応演算から得られる添加基準との比較によつて行
なわれる。同様にして内管の圧力が減じ、流量が
多くなつた際は添加酸素量を減ずるか又は無添加
とするように制御が行なわれる。 FIG. 9 is a block diagram showing the control procedure performed by the gas flow control device 24 using the relationship between P and Q. Based on the input signal, the predetermined hole area ratio
The aperture ratio of the lower nozzle is calculated from the PQ diagram,
If it conforms to the desired standard porosity and the desired flow rate is ensured together with the amount of blowing from the outer tube 7, then the blowing of carbon dioxide will be carried out as is. In this case, the flow velocity at the outlet of the outer tube 7 is maintained at a specific velocity or higher,
The mash room can be improved by changing the flow rate of the inner pipe 8, or by changing the ratio of the outer pipe flow rate to the inner pipe flow rate, or by keeping the inner pipe flow rate constant and changing the outer pipe flow rate. Although it is possible to maintain a good shape, this type of control often fails to maintain a good shape, so in that case, the amount of oxygen to be added to the carbon dioxide in the inner tube 8 is adjusted as described above. 0~ of carbon dioxide
Very good results can be obtained if it is constantly added in the range of 30%. Furthermore, when the pressure in the inner pipe increases and the flow rate decreases, the gas flow control device 24 calculates the amount of oxygen to be added so as to obtain the desired lower nozzle opening ratio, and issues an operation command to the control valve 20. Served. The calculation is performed by comparison with past blowing results and/or addition standards obtained from reaction calculations. Similarly, when the pressure in the inner tube decreases and the flow rate increases, control is performed to reduce the amount of added oxygen or to eliminate the addition of oxygen.
〔実施例 １〕
C4.3％，Si0.50％，Mn0.50％，残りFeの溶銑
180Tonに上ノズルから酸素を28000Nm3／Hr、
下ノズルから二酸化炭素のみを800Nm3／Hr吹込
んで精錬した際の吹錬時間経過にともなう下ノズ
ル内管の二酸化炭素吹込量と圧力変化を第１０図
に示す。この例では予定吹錬ストツプ時期の直前
に内，外管の圧力および流量制御にかかわらずマ
ツシユルームは閉塞し（異常に過大になつたもの
と考えられる）所望の底吹ガス流量が得られず、
底吹による撹拌効果が少なく、得られた溶鋼の成
分は不満足なものであつた。３７は目標とした基
準流量を示す。[Example 1] Hot metal with C4.3%, Si0.50%, Mn0.50%, remaining Fe
28000Nm 3 /Hr of oxygen from the upper nozzle to 180Ton,
Figure 10 shows the amount of carbon dioxide blown into the inner pipe of the lower nozzle and the change in pressure as the blowing time elapses when refining is performed by blowing only carbon dioxide at 800 Nm 3 /Hr from the lower nozzle. In this example, just before the scheduled blowing stop time, the pine room was blocked regardless of the pressure and flow rate control of the inner and outer pipes (it is thought that the volume became abnormally large), and the desired bottom blowing gas flow rate could not be obtained.
The stirring effect due to bottom blowing was small, and the composition of the obtained molten steel was unsatisfactory. 37 indicates the target reference flow rate.
〔実施例 ２〕
C4.4％，Si0.55％，Mn0.60％，残りが不可避不
純物を含むFeからなる溶銑180tonに上ノズルか
ら酸素を28000Nm3／Hr、下ノズルから二酸化炭
素を800Nm3／Hr吹込む吹錬において内管に二酸
化炭素の圧力変化にあわせ酸素を間欠的に添加し
た例を第１１図に示す。[Example 2] To 180 tons of hot metal consisting of 4.4% C, 0.55% Si, 0.60% Mn, and the rest Fe containing unavoidable impurities, 28000 Nm 3 /Hr of oxygen was applied from the upper nozzle, and 800 Nm 3 of carbon dioxide was applied from the lower nozzle. Figure 11 shows an example in which oxygen is intermittently added to the inner tube in accordance with changes in the pressure of carbon dioxide during blowing with /Hr.
図において点３８，３９は酸素添加を開始した
時期で点４０，４１は酸素添加を止めた時点であ
り、マツシユルームは所望の通りの形状を保つた
ものと推定され、二酸化炭素の吹込量は所望の基
準を達成した。その結果得られた溶鋼の成分も所
定の目標に達した。 In the figure, points 38 and 39 are the time when oxygen addition was started, and points 40 and 41 are the time when oxygen addition was stopped.It is assumed that the pine room maintained the desired shape, and the amount of carbon dioxide blown was the desired amount. achieved the standard. The composition of the resulting molten steel also reached the specified target.
本発明の如く下ノズルの閉塞を防止し吹錬を完
了した場合、下ノズルおよびその周辺の炉体煉瓦
（底部耐火物）の損傷は非常に少なく（たとえば
下ノズルの損傷は１チヤージ0.8mm程度）、実施例
１のような場合下ノズルおよび周辺レンガの損傷
はかなり大きく（たとえば下ノズルの損傷は１チ
ヤージ３mm）その差はきわめて顕著である。 When blowing is completed while preventing blockage of the lower nozzle as in the present invention, damage to the lower nozzle and the surrounding furnace bricks (bottom refractories) is very small (for example, damage to the lower nozzle is approximately 0.8 mm per charge). ), in a case like Example 1, the damage to the lower nozzle and the surrounding bricks was quite large (for example, the damage to the lower nozzle was 3 mm per charge), and the difference is extremely significant.
また、二酸化炭素は炉内で70〜90％が一酸化炭
素に変化するため、転炉排ガス未燃焼方式で排ガ
スを回収した場合、可燃ガス回収量は前記二酸化
炭素吹込量に比例することになり、本発明によつ
て円滑に吹錬が出来るので、可燃ガス回収量も増
加し、経済効果が増大する。 Additionally, 70 to 90% of carbon dioxide changes to carbon monoxide in the furnace, so if exhaust gas is recovered using the converter exhaust gas unburned method, the amount of combustible gas recovered will be proportional to the amount of carbon dioxide injected. Since blowing can be carried out smoothly according to the present invention, the amount of combustible gas recovered also increases, and the economic effect increases.
前記実施例では200Nm3／chの二酸化炭素吹込
みにより一酸化炭素の増量分は160Nm3／chであ
つた。 In the above example, the amount of carbon monoxide increased by 160 Nm 3 /ch by blowing in carbon dioxide at 200 Nm 3 /ch.
第１図ａ，ｂは下ノズルから二酸化炭素を吹込
む際のマツシユルームに関する部分断面概要図、
第２図ａ，ｂは内，外管からなる下ノズルを介し
て二酸化炭素を吹込む際のマツシユルームに関す
る部分断面概要図、第３図は本発明にかかる下ノ
ズルの周面ガス流を説明するための部分概略斜視
図、第４図、第５図は下ノズルの直径方向でのガ
ス流速変化を示すグラフ、第６図は本発明にかか
る方法を実施するための実施例装置概略ブロツク
線図、第７図は本発明にかかるマツシユルーム部
分断面概換図、第８図は内管の閉塞状況を説明す
るためのガス圧力と流量の関係を示すグラフ、第
９図はガス流制御装置での酸素添加演算の１例を
示すブロツク線図、第１０図，第１１図は吹錬経
過にともなう内管からの吹込み二酸化炭素の圧力
と流量の変化を示す実施例グラフである。
１……底部耐火物、２，２ａ……下ノズル、４
……溶湯、５……マツシユルーム、６……通気
孔、７……外筒、８……内筒、１１……細通気
孔、７０，８０……二酸化炭素供給管、１４……
酸素供給管、１５，１６，１７……圧力計、１
８，１９，２０……制御弁、２１，２２，２３…
…流量計、２４……ガス流制御装置、２５……上
ノズル、２６……転炉炉体、２７……溶湯、３７
……目標基準流量。
Figures 1a and b are partial cross-sectional schematic diagrams of the pine room when blowing carbon dioxide from the lower nozzle;
Figures 2a and b are partial cross-sectional schematic views of the pine room when carbon dioxide is injected through the lower nozzle consisting of inner and outer tubes, and Figure 3 explains the gas flow on the circumferential surface of the lower nozzle according to the present invention. FIG. 4 and FIG. 5 are graphs showing changes in gas flow velocity in the diametrical direction of the lower nozzle, and FIG. 6 is a schematic block diagram of an embodiment of an apparatus for carrying out the method according to the present invention. , FIG. 7 is a schematic cross-sectional view of a part of the pine room according to the present invention, FIG. 8 is a graph showing the relationship between gas pressure and flow rate to explain the blockage situation of the inner pipe, and FIG. 9 is a graph showing the relationship between gas pressure and flow rate in the gas flow control device. A block diagram showing an example of oxygen addition calculation, and FIGS. 10 and 11 are example graphs showing changes in the pressure and flow rate of carbon dioxide blown from the inner pipe as blowing progresses. 1...Bottom refractory, 2, 2a...Lower nozzle, 4
... Molten metal, 5 ... Pine room, 6 ... Ventilation hole, 7 ... Outer cylinder, 8 ... Inner cylinder, 11 ... Fine air hole, 70, 80 ... Carbon dioxide supply pipe, 14 ...
Oxygen supply pipe, 15, 16, 17...pressure gauge, 1
8, 19, 20... control valve, 21, 22, 23...
...flow meter, 24 ... gas flow control device, 25 ... upper nozzle, 26 ... converter furnace body, 27 ... molten metal, 37
...Target standard flow rate.
Claims (1)
素を吹込む上下吹転炉製錬方法において、該下ノ
ズルを内外筒からなる同心二重管構造とし、前記
外筒から二酸化炭素を、前記内筒から二酸化炭素
に加えてマツシユルーム通気孔保持用酸素を添加
して吹込むことを特徴とする上下吹転炉精錬方
法。 ２ 下ノズルが閉塞状態になつた際にのみ、前記
内筒から吹込む二酸化炭素にマツシユルーム通気
孔保持用酸素を添加する特許請求の範囲第１項記
載方法。 ３ 下ノズルの通気状況および閉塞状態を、前記
吹込み二酸化炭素の供給圧力および流量変動もし
くはそのいずれかの経時測定値とあらかじめ求め
られている基準値との比較によつて検出し、酸素
添加時期および添加量を決定して添加する特許請
求の範囲第１項記載の方法。[Scope of Claims] 1. In a top-down blowing furnace smelting method in which oxygen is blown into an upper nozzle and carbon dioxide is blown into a lower nozzle, the lower nozzle has a concentric double pipe structure consisting of an inner and outer cylinder, and the carbon dioxide is injected from the outer cylinder. A method for refining in a top-bottom blowing converter furnace, characterized in that carbon is blown into the inner cylinder by adding oxygen for maintaining a pine room vent in addition to carbon dioxide. 2. The method according to claim 1, wherein oxygen for maintaining the pine room ventilation hole is added to the carbon dioxide blown from the inner cylinder only when the lower nozzle is in a closed state. 3. Detect the ventilation status and blockage status of the lower nozzle by comparing the supply pressure and flow rate fluctuation of the blown carbon dioxide, or the measured value over time of either of them, with a predetermined reference value, and determine the timing of oxygen addition. The method according to claim 1, wherein the amount of addition is determined and added.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3354981A JPS57149409A (en) | 1981-03-09 | 1981-03-09 | Refining by top and bottom blowing converter |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3354981A JPS57149409A (en) | 1981-03-09 | 1981-03-09 | Refining by top and bottom blowing converter |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57149409A JPS57149409A (en) | 1982-09-16 |
| JPS635448B2 true JPS635448B2 (en) | 1988-02-03 |
Family
ID=12389631
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3354981A Granted JPS57149409A (en) | 1981-03-09 | 1981-03-09 | Refining by top and bottom blowing converter |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57149409A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02140346U (en) * | 1989-04-20 | 1990-11-22 |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| TWI630276B (en) * | 2016-09-02 | 2018-07-21 | 中國鋼鐵股份有限公司 | Method for controlling status of accretion formation in pyrometallurgical treatment |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55161014A (en) * | 1979-05-31 | 1980-12-15 | Sumitomo Metal Ind Ltd | Refining method for steel |
| JPS5613423A (en) * | 1979-07-06 | 1981-02-09 | Sumitomo Metal Ind Ltd | Refining method for steel |
-
1981
- 1981-03-09 JP JP3354981A patent/JPS57149409A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS55161014A (en) * | 1979-05-31 | 1980-12-15 | Sumitomo Metal Ind Ltd | Refining method for steel |
| JPS5613423A (en) * | 1979-07-06 | 1981-02-09 | Sumitomo Metal Ind Ltd | Refining method for steel |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH02140346U (en) * | 1989-04-20 | 1990-11-22 |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57149409A (en) | 1982-09-16 |
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