JPH0478690B2 - - Google Patents
Info
- Publication number
- JPH0478690B2 JPH0478690B2 JP62016899A JP1689987A JPH0478690B2 JP H0478690 B2 JPH0478690 B2 JP H0478690B2 JP 62016899 A JP62016899 A JP 62016899A JP 1689987 A JP1689987 A JP 1689987A JP H0478690 B2 JPH0478690 B2 JP H0478690B2
- Authority
- JP
- Japan
- Prior art keywords
- molten steel
- furnace
- electric arc
- nozzle
- steel
- 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 - Lifetime
Links
- 229910000831 Steel Inorganic materials 0.000 claims description 61
- 239000010959 steel Substances 0.000 claims description 61
- 238000010079 rubber tapping Methods 0.000 claims description 32
- 238000003756 stirring Methods 0.000 claims description 32
- 238000007664 blowing Methods 0.000 claims description 27
- 238000010891 electric arc Methods 0.000 claims description 24
- 238000006477 desulfuration reaction Methods 0.000 claims description 15
- 230000023556 desulfurization Effects 0.000 claims description 15
- 239000002893 slag Substances 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 13
- 238000002844 melting Methods 0.000 claims description 11
- 230000008018 melting Effects 0.000 claims description 11
- 239000003795 chemical substances by application Substances 0.000 claims description 7
- 239000002994 raw material Substances 0.000 claims description 7
- 230000003009 desulfurizing effect Effects 0.000 claims description 5
- 239000007789 gas Substances 0.000 description 28
- 239000002184 metal Substances 0.000 description 10
- 229910052751 metal Inorganic materials 0.000 description 10
- 230000000694 effects Effects 0.000 description 8
- 230000002093 peripheral effect Effects 0.000 description 8
- 238000002156 mixing Methods 0.000 description 5
- 238000004090 dissolution Methods 0.000 description 4
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 238000010586 diagram Methods 0.000 description 3
- 239000011819 refractory material Substances 0.000 description 3
- 239000007787 solid Substances 0.000 description 3
- 238000001816 cooling Methods 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- 238000010309 melting process Methods 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910000604 Ferrochrome Inorganic materials 0.000 description 1
- 229910000616 Ferromanganese Inorganic materials 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 238000007667 floating Methods 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- DALUDRGQOYMVLD-UHFFFAOYSA-N iron manganese Chemical compound [Mn].[Fe] DALUDRGQOYMVLD-UHFFFAOYSA-N 0.000 description 1
- 239000007769 metal material Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000011295 pitch Substances 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 238000009991 scouring Methods 0.000 description 1
- 238000004904 shortening Methods 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
- Vertical, Hearth, Or Arc Furnaces (AREA)
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、三相交流又は直流の電弧によりスク
ラツプ、鉱石、金属材料等の溶解、精練を行う電
弧炉の操業方法及び装置に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method and apparatus for operating an electric arc furnace for melting and scouring scrap, ore, metal materials, etc. using a three-phase AC or DC electric arc.
従来、電弧炉の操業においては、スクラツプ等
の装入原料を溶解する工程で、炉壁から助燃ガス
や溶解促進のための酸素が吹き込まれている。こ
のとき、電弧炉の炉底は、その直径に対し深さの
極めて浅い、いわゆるシヤローバスの状態にあ
る。このために、溶融金属浴を攪拌する力は極め
て弱い。加えて、電極から付与される熱も溶融金
属浴の上面のみを加熱するために消費されるの
で、溶融金属浴内に対流が起き難く、温度及び成
分が不均一になる。
Conventionally, in the operation of an electric arc furnace, in the process of melting charged raw materials such as scrap, combustion supporting gas and oxygen to promote melting are blown into the furnace wall. At this time, the bottom of the electric arc furnace is in a so-called shallow bath state where the depth is extremely shallow relative to its diameter. For this reason, the power to stir the molten metal bath is extremely weak. In addition, the heat applied from the electrodes is also consumed to heat only the upper surface of the molten metal bath, making it difficult for convection to occur within the molten metal bath, resulting in non-uniform temperature and composition.
また、攪拌力が弱いことから、溶融金属浴とフ
ラツクス層との間で冶金的反応が平衡となる状態
に達せず、極めて反応効率が悪い。その結果、フ
エロマンガン、フエロクロム等の添加材の原単位
の悪化、スラグ中のトータルFeが上昇すること
に起因した鉄ロスの増加等の欠点があつた。この
欠点を避けるため攪拌力を強化するとき、脱炭率
の向上、鋼中の含有ガスの除去等による清浄化が
図られ、極めて大きなメリツトが期待される。 Furthermore, since the stirring force is weak, the metallurgical reaction between the molten metal bath and the flux layer does not reach an equilibrium state, resulting in extremely poor reaction efficiency. As a result, there were drawbacks such as a deterioration in the basic unit of additives such as ferromanganese and ferrochrome, and an increase in iron loss due to an increase in the total Fe in the slag. In order to avoid this drawback, when the stirring power is strengthened, the decarburization rate is improved, the gas contained in the steel is removed, and the steel is cleaned, and extremely large benefits are expected.
しかし、電弧炉の場合、溶融金属浴の揺動や激
しい波立ちは、開口部からの溶融金属の洩出、水
冷パネルの溶損、アークの不安定化等の問題を派
生するおそれがある。このため、これらの危険性
を回避して激しい攪拌力を溶融金属浴に与えるこ
とは実操業的には困難とされていた。そこで、炉
床部から不活性ガスまたは酸化性ガス等を炉内に
吹き込むことにより、溶解を促進させる方法等が
提案されている。 However, in the case of an electric arc furnace, shaking or violent rippling of the molten metal bath may lead to problems such as leakage of molten metal from the opening, melting of the water cooling panel, and instability of the arc. For this reason, it has been considered difficult in actual operation to avoid these risks and apply a strong stirring force to the molten metal bath. Therefore, methods have been proposed in which inert gas, oxidizing gas, or the like is blown into the furnace from the hearth to promote melting.
この電弧炉における溶解促進の方法として、た
とえば、特開昭50−92807号公報に記載されてい
るものがある。これは、溶融金属浴の攪拌を行う
ために炉底に吹込みノズルを配置したもので、吹
込みガスによつて溶融金属浴を強制的に流動化す
る手段を採用したものである。 As a method of promoting melting in this electric arc furnace, there is a method described, for example, in Japanese Patent Application Laid-Open No. 92807/1983. This has a blowing nozzle placed at the bottom of the furnace to stir the molten metal bath, and employs a means of forcibly fluidizing the molten metal bath by blowing gas.
しかしながら、単に底吹きのノズルを配置する
だけでは、炉内の浴全体を大きな攪拌強度で攪拌
することができないことは、実験的にも確認され
ている。そして、ノズルの配置や吹込みガスの供
給方向や流量の調整が、効率の良い攪拌のための
重要な条件となることも判つている。
However, it has been experimentally confirmed that simply arranging bottom-blowing nozzles does not allow the entire bath in the furnace to be stirred with a high stirring intensity. It has also been found that the arrangement of the nozzle and the adjustment of the supply direction and flow rate of the blown gas are important conditions for efficient stirring.
ところで、精練においては従来から、脱硫を十
分に行つて出鋼時にスラグを除いて溶鋼だけを排
出するスラグフリータツピングが行われている。
しかし、特に普通鋼のように出鋼脱硫が一般に行
われる場合には、溶鋼とスラグを同時に排出する
ため、スラグによる溶鋼内への不純物の混入や出
鋼口の耐火物寿命が短くなる欠点があるにもかか
わらず、これを解消できないという問題があつ
た。 Incidentally, in refining, slag-free tapping has conventionally been performed in which sufficient desulfurization is performed and slag is removed during tapping and only molten steel is discharged.
However, when tapping desulfurization is generally performed, especially for ordinary steel, the molten steel and slag are discharged at the same time, which has the drawbacks of contaminating the molten steel with impurities and shortening the life of the refractories at the tapping port. Despite this, there was a problem that could not be resolved.
本発明は、このような電弧炉における問題に鑑
み、電弧炉の操業において、底吹ノズルにより溶
融金属浴の攪拌を十分に行うと共に炉内で溶鋼の
脱硫を可能として、鋼の清浄化を図ると共に炉壁
耐火物の寿命を長くすることを目的とする。 In view of such problems in electric arc furnaces, the present invention aims to clean the steel by sufficiently stirring the molten metal bath using a bottom blowing nozzle and desulfurizing the molten steel in the furnace during operation of the electric arc furnace. At the same time, the purpose is to extend the life of the furnace wall refractories.
本発明の電弧炉底吹操業方法は、その目的を達
成するために、電弧炉の炉底に底吹ノズルを設け
て溶鋼の攪拌を行なう電弧炉において、出鋼前の
段階において予め炉内に脱硫剤を投入し、前記底
吹ノズルから攪拌用ガスを吹き込んで装入原料を
溶解すると同時に脱硫処理し、更に脱硫後のスラ
グを含む溶鋼の一部を炉内に残留させて出鋼工程
を行うことを特徴とする。
In order to achieve the objective, the electric arc furnace bottom blowing operation method of the present invention is an electric arc furnace in which a bottom blowing nozzle is provided at the bottom of the electric arc furnace to stir molten steel. A desulfurizing agent is introduced, and stirring gas is blown in from the bottom blowing nozzle to melt the charged raw material and simultaneously desulfurize it.Furthermore, a part of the molten steel containing slag after desulfurization is left in the furnace to perform the steel tapping process. It is characterized by doing.
また、そのために使用する電弧炉は、炉体内の
炉床をそのほぼ中央域が最も深い凹状に形成する
と共に攪拌用のガスを溶鋼内に吹き込む底吹ノズ
ルを該炉床に設け、前記底吹ノズルが鋼浴中に常
に浸漬されることが可能な高さに開口を持つ出鋼
口を設けたことを特徴とする。 In addition, the electric arc furnace used for this purpose has a hearth inside the furnace body formed in a concave shape with the deepest part approximately at the center, and a bottom blowing nozzle for blowing stirring gas into the molten steel is installed in the hearth. The present invention is characterized in that a tap opening is provided at a height that allows the nozzle to be immersed in the steel bath at all times.
以下、図面を参照しながら、実施例により本発
明の特徴を具体的に説明する。
Hereinafter, the features of the present invention will be specifically explained using examples with reference to the drawings.
第１図及び第２図は、それぞれ本発明の第１実
施例における電弧炉の縦断面図及び水平断面図で
ある。 1 and 2 are a longitudinal sectional view and a horizontal sectional view, respectively, of an electric arc furnace in a first embodiment of the present invention.
電弧炉の炉体１の炉壁２には、水冷パネル３が
取り付けられている。また、炉体１の中心部分に
は３本の電極４が設けてられており、これらの電
極４に通電することにより電弧炉に投入されたス
クラツプ等の原料を溶解する。また、炉体１のシ
ルレベル以下にある炉床５の炉体１中心付近には
中心ノズル６が設けられており、炉床５の外周部
には少なくとも１個の外周ノズル７が設けられて
いる。 A water cooling panel 3 is attached to a furnace wall 2 of a furnace body 1 of an electric arc furnace. Furthermore, three electrodes 4 are provided at the center of the furnace body 1, and by energizing these electrodes 4, raw materials such as scraps fed into the electric arc furnace are melted. Further, a center nozzle 6 is provided near the center of the furnace body 1 of the hearth 5 below the sill level of the furnace body 1, and at least one outer peripheral nozzle 7 is provided at the outer periphery of the hearth 5. .
炉体１の左右には、固体原料を装入するための
作業口８と溶解・脱硫後の溶鋼を受鋼鍋（図示せ
ず）に排出する出鋼口９を設けている。作業口８
は原料の溶解によつて得られる浴の上面より上レ
ベルに位置している。また、出鋼口９は炉体１の
内径よりも外部に突出した部分に位置し、第１図
の定常状態の姿勢のときにほぼ鉛直方向に開口軸
線を持つように形成されている。そして、出鋼口
９の上面部は炉床５の最下端よりも高いレベルに
位置し、更に直下には溶鋼の排出を停止するため
のストツパ１０を開閉自在に設けている。 On the left and right sides of the furnace body 1, there are provided a working port 8 for charging solid raw materials and a tapping port 9 for discharging molten steel after melting and desulfurization into a receiving ladle (not shown). Work opening 8
is located at a level above the top of the bath obtained by dissolving the raw materials. Further, the tap hole 9 is located at a portion that projects outward from the inner diameter of the furnace body 1, and is formed so that its opening axis runs approximately vertically when in the steady state attitude shown in FIG. The upper surface of the tapping port 9 is located at a higher level than the lowest end of the hearth 5, and a stopper 10 for stopping the discharge of molten steel is provided directly below so as to be openable and closable.
また、炉床５に配置した中心ノズル６は、炉体
１内の略中心に位置し、吹き込むガスの流線が略
鉛直方向を指向するように設置される。一方、外
周ノズル７は、本実施例の場合では、中心ノズル
６を中心とする同一円上に等しい円周ピツチで３
個配置され、ガスの流線が鉛直方向よりもやや炉
芯方向に傾斜するように設置される。そして、炉
体１の半径をＲとするとき、中心ノズル６を中心
とする半径ｒが0.2〜0.8Rの領域内の円上にこれ
らの外周ノズル７を配列する。このような炉体１
の半径に対する外周ノズル７の領域を限定するこ
とにより、ガス吹き込みによる浴の盛り上がり高
さの規制や激しい波立ちの防止を図つて、浴の洩
出を防止できる。また、中心ノズル６との併用に
よつて、浴を大きな攪拌強度で短時間に均一攪拌
を可能とすると共に、滞留を生じやすい炉芯側の
浴を効率的に混合攪拌できる効果によつて、浴を
均一攪拌することができる。その結果、固体装入
物の溶解促進、冶金反応の向上、温度及び成分の
均一化が可能となる。 Further, the center nozzle 6 disposed on the hearth 5 is located approximately at the center within the furnace body 1, and is installed so that the streamline of the gas blown therein is directed approximately vertically. On the other hand, in the case of this embodiment, the outer circumferential nozzle 7 is arranged at three equal circumferential pitches on the same circle centered on the center nozzle 6.
They are arranged so that the gas streamlines are slightly inclined toward the furnace core rather than vertically. When the radius of the furnace body 1 is R, these outer circumferential nozzles 7 are arranged on a circle within a region with a radius r of 0.2 to 0.8R centered on the central nozzle 6. Furnace body 1 like this
By limiting the area of the outer circumferential nozzle 7 with respect to the radius of the bath, the height of the rise of the bath due to gas blowing can be restricted and severe ripples can be prevented, thereby preventing leakage of the bath. In addition, when used in combination with the center nozzle 6, it is possible to uniformly stir the bath in a short time with high stirring intensity, and the bath on the furnace core side, where stagnation tends to occur, can be efficiently mixed and stirred. The bath can be stirred uniformly. As a result, it is possible to accelerate the dissolution of the solid charge, improve the metallurgical reaction, and equalize the temperature and components.
更に、これらの中心ノズル６及び外周ノズル７
に攪拌用のガスを供給する供給装置２０が設備さ
れる。この供給装置２０からは、CO2、CO、
Ar、N2、O2及び空気等の酸化性又は不活性ガス
等が、中心ノズル６及び外周ノズル７へ配管２１
−１，２１−２，２１−３，２１−４によつて供
給される。そして、これらの中心ノズル６及び外
周ノズル７から吹き込むガスの流量を調節するた
めに、各配管２１−１，２１−２，２１−３，２
１−４には調節弁２２−１，２２−２，２２−
３，２２−４が設けられる。 Furthermore, these center nozzles 6 and outer peripheral nozzles 7
A supply device 20 for supplying stirring gas is installed. From this supply device 20, CO 2 , CO,
Oxidizing or inert gases such as Ar, N 2 , O 2 and air are passed through the pipe 21 to the center nozzle 6 and the outer nozzle 7.
-1, 21-2, 21-3, 21-4. In order to adjust the flow rate of gas blown from these central nozzles 6 and outer peripheral nozzles 7, each pipe 21-1, 21-2, 21-3, 2
1-4 has control valves 22-1, 22-2, 22-
3, 22-4 are provided.
ここで、電弧炉の操業においては、溶鋼の脱硫
を行うために、出鋼前の段階で予め脱硫剤を投入
しておく。 Here, in the operation of the electric arc furnace, a desulfurizing agent is added in advance at a stage before tapping in order to desulfurize the molten steel.
ここで、浴の攪拌を均一に良好に行うと同時に
脱硫の促進を図るために、中心ノズル６及び外周
ノズル７から吹き込む攪拌用ガスのそれぞれの流
量を適切に設定することが必要である。このこと
を、第３図の線図によつて説明する。 Here, in order to stir the bath uniformly and well and at the same time to promote desulfurization, it is necessary to appropriately set the respective flow rates of the stirring gas blown from the center nozzle 6 and the peripheral nozzle 7. This will be explained using the diagram in FIG.
第３図は、中心ノズル６から吹き込む攪拌用ガ
スの流量をQ1及び３個の外周ノズル７からの総
流量をQ2としたとき、これらの流量比Q1／Q2の
変化に対する浴の挙動を示すものである。すなわ
ち、横軸に流量比Q1／Q2をとり、縦軸にQ1／Q2
＝0.1を基準として炉壁部分の波打ち高さＨ（実線
で示す）及び均一混合時間τ（破線で示す）をと
つたものである。波打ち高さＨは攪拌用ガスの吹
き込みによつて発生する浴の波動の炉壁部分の高
さであり、均一混合時間τは浴が均一に安定した
攪拌混合となるまでに要する時間である。 Figure 3 shows the relationship between the bath flow rate and the change in the flow rate ratio Q 1 /Q 2 , where Q 1 is the flow rate of the stirring gas blown from the central nozzle 6 and Q 2 is the total flow rate from the three outer nozzles 7. It shows the behavior. In other words, the horizontal axis shows the flow rate ratio Q 1 /Q 2 , and the vertical axis shows Q 1 /Q 2
= 0.1 as a reference, and the undulation height H (indicated by a solid line) of the furnace wall portion and the uniform mixing time τ (indicated by a broken line) are taken. The undulation height H is the height of the furnace wall portion of the bath undulations generated by blowing the stirring gas, and the uniform mixing time τ is the time required until the bath becomes uniformly and stably stirred and mixed.
この線図によると、中心ノズル６からのガス量
を減少してゆくと、Q1／Q2がほぼ0.2程度の付近
で中心ノズル６の存在効果が薄れ、３本の外周ノ
ズル７だけと同様の現象となる。つまり、波打ち
高さＨ及び均一混合時間τは共に上昇し、浴の挙
動が好ましくない状況になる。また、逆にQ1／
Q2の値を上げてゆくと、中心ノズル６からのガ
ス吹込み量が過大となつて浴の盛り上がりが大き
くなる。そして、この浴の盛り上がりは炉の中心
付近で生じるため、旋回揺動を伴うようになり、
結果的に波打ち高さＨ及び均一混合時間τは共に
上昇してしまう。 According to this diagram, as the amount of gas from the center nozzle 6 decreases, the effect of the presence of the center nozzle 6 fades when Q 1 /Q 2 is about 0.2, and the effect of the presence of the center nozzle 6 becomes similar to that of only the three outer nozzles 7. This phenomenon occurs. In other words, both the corrugation height H and the uniform mixing time τ increase, resulting in an unfavorable bath behavior. Also, conversely, Q 1 /
As the value of Q 2 is increased, the amount of gas blown from the central nozzle 6 becomes excessive and the swell of the bath increases. Since this rise in the bath occurs near the center of the furnace, it becomes accompanied by swirling and shaking.
As a result, both the corrugation height H and the uniform mixing time τ increase.
以上のことから、中心ノズル６及び外周ノズル
７から吹き込むそれぞれの攪拌用ガスの流量Q1，
Q2の比には最適範囲が存在することが認められ
る。そして、第３図の線図を基にして、これらの
流量比Q1／Q2が0.2〜５の値の範囲で調整しなが
ら攪拌を行えばよいことが明らかとなつた。 From the above, the flow rate Q 1 of each stirring gas blown from the center nozzle 6 and the outer nozzle 7,
It is recognized that an optimal range exists for the ratio of Q 2 . Based on the diagram in FIG. 3, it has become clear that stirring can be carried out while adjusting the flow rate ratio Q 1 /Q 2 within the range of 0.2 to 5.
このような中心ノズル６及び外周ノズル７から
の攪拌用ガスの吹き込みによつて、浴が均一に攪
拌されて溶解を促進し、かつ投入している脱硫剤
の効果によつて溶鋼の脱硫工程が同時に進行す
る。 By blowing the stirring gas from the center nozzle 6 and the outer nozzle 7, the bath is uniformly stirred to promote melting, and the desulfurization process of the molten steel is accelerated by the effect of the desulfurization agent added. proceed at the same time.
この後、ストツパ１０を開いて溶鋼を出鋼口９
から受鋼鍋に排出する。このとき、出鋼口９は略
鉛直にその開口軸線を持つので、溶鋼はそのヘツ
ドによつてこの出鋼口９から速やかに流れ出る。
そして、炉床５は図示のように中央部が最も深い
凹形状となつているため、最終的には浴の上面が
第１図の一点鎖線のレベルに達して排出が止ま
る。すなわち、出鋼口９の上端は炉床５よりも上
に盛り上がつた位置にあるため、炉体１を第１図
のように保持した状態では、この出鋼口９の上端
レベルが浴を排出可能な上限となる。 After that, open the stopper 10 and pour the molten steel into the tapping port 9.
Discharge from the container into a receiving ladle. At this time, since the tap hole 9 has its opening axis substantially vertically, the molten steel quickly flows out from the tap hole 9 by its head.
Since the hearth 5 has a concave shape with the deepest depth at the center as shown in the figure, the upper surface of the bath eventually reaches the level indicated by the dashed line in FIG. 1 and the discharge stops. That is, since the upper end of the tap hole 9 is in a raised position above the hearth 5, when the furnace body 1 is held as shown in FIG. is the upper limit that can be discharged.
このように、浴の一部を炉体１内に残留させる
と、浴の上面に浮上するスラグが出鋼口９に流れ
込まずに溶鋼のみを排出できる。このため、脱硫
処理された溶鋼がスラグを伴うことなく受鋼鍋に
排出され、鋼の清浄化が図れるとともに受鋼鍋の
耐火物原単位の削減も可能となる。また、出鋼口
９をスラグが通過しないため、流路壁の溶損量も
低下し、炉壁耐火物の寿命の向上も図れる。 When a portion of the bath is left in the furnace body 1 in this manner, only the molten steel can be discharged without the slag floating on the upper surface of the bath flowing into the tapping port 9. Therefore, the desulfurized molten steel is discharged into the steel receiving ladle without slag, making it possible to purify the steel and reducing the refractory unit consumption of the steel receiving ladle. Furthermore, since the slag does not pass through the tapping port 9, the amount of erosion on the flow path wall is reduced, and the life of the furnace wall refractories can be improved.
更に、炉床５の下部にはスラグを含む溶鋼の一
部が残存するので、中心ノズル６及び外周ノズル
７は常に溶鋼内に浸漬された状態となる。特に、
残留する溶鋼の量を最初の状態の1/10以上に設定
した場合には、溶鋼量が十分であるために、中心
ノズル６及び外周ノズル７に急激な温度変化を与
えることが防止される。このため、これらの中心
ノズル６及び外周ノズル７の損傷を避けることが
でき、寿命の向上が可能となる。したがつて、固
体原料の再装入後のガス吹き込みにおいても、流
路の詰まり等を伴うことなく円滑に作動でき、浴
の攪拌による溶解促進を確実に果たすことができ
る。 Furthermore, since a portion of the molten steel containing slag remains in the lower part of the hearth 5, the center nozzle 6 and the outer nozzle 7 are always immersed in the molten steel. especially,
When the amount of remaining molten steel is set to 1/10 or more of the initial state, the amount of molten steel is sufficient, and sudden temperature changes are prevented from being applied to the center nozzle 6 and the outer peripheral nozzle 7. Therefore, damage to the center nozzle 6 and the outer nozzle 7 can be avoided, and the service life can be improved. Therefore, even during gas blowing after recharging the solid raw material, it can operate smoothly without clogging the flow path, and dissolution can be reliably promoted by stirring the bath.
第４図及び第５図は本発明の第２実施例を示す
縦断面図と水平断面図である。これらの図におい
て、第１図及び第２図の部材等に対応するものは
同一の符番で指示し、その説明を省略した。ただ
し、本例にあつては、出鋼口９の近傍にも底吹ノ
ズル１１を設けている点が第１実施例と異なる。 FIGS. 4 and 5 are a longitudinal sectional view and a horizontal sectional view showing a second embodiment of the present invention. In these figures, parts corresponding to those in FIGS. 1 and 2 are designated by the same reference numerals, and their explanations are omitted. However, this example differs from the first example in that a bottom blowing nozzle 11 is also provided near the tap hole 9.
底吹ノズル１１は、出鋼口９よりも炉芯側の近
傍位置にその吹込み口を開設し、ほぼ鉛直方向に
攪拌用のガスを吹き込めるように設置される。ま
た、他の中心ノズル６及び３個配置した外周ノズ
ル７と同様に、攪拌用ガスの供給装置２０に配管
２１−５によつてガスが供給され、流量を調節弁
２２−５により調節可能としている。 The bottom blowing nozzle 11 has an inlet in the vicinity of the furnace core side than the tapping port 9, and is installed so that stirring gas can be blown in a substantially vertical direction. Also, like the other central nozzles 6 and the three peripheral nozzles 7, gas is supplied to the stirring gas supply device 20 through a pipe 21-5, and the flow rate can be adjusted by a control valve 22-5. There is.
この第２実施例においても、各ノズルからの吹
込みガスの流量設定を前記のような条件で行い且
つ脱硫剤を投入しておくことにより、溶解の促進
及び鋼浴の脱硫を同時に行える。また、中心ノズ
ル６、外周ノズル７及び底吹ノズル１１は、出鋼
後においてもスラグを含む溶鋼内に浸漬されるの
で、前記と同様にスラグコーテイングされ、寿命
の向上も可能である。 In this second embodiment as well, by setting the flow rate of the blown gas from each nozzle under the conditions described above and adding a desulfurizing agent, it is possible to promote melting and desulfurize the steel bath at the same time. Furthermore, since the center nozzle 6, outer circumferential nozzle 7, and bottom blowing nozzle 11 are immersed in molten steel containing slag even after tapping, they are coated with slag in the same manner as described above, and their lifespan can be improved.
そして、特に出鋼口９の近傍にも底吹ノズル１
１を配置したことにより、この出鋼口９部分に滞
留するスクラツプ塊１２の溶解促進が可能であ
る。したがつて、出鋼口９に大きなスクラツプ塊
１２があつて出鋼流路を閉塞する状態であつて
も、底吹ノズル１１からの攪拌用ガスの効果によ
つて、このスクラツプ塊１２を集中的に溶解を促
進させる。そして、他の中心ノズル６及び外周ノ
ズル７による攪拌効果も併せて出鋼口９部分に堆
積するスクラツプを溶解させることができる。そ
の結果、出鋼工程において、出鋼口９に溶鋼詰り
を伴うようなことはなく、速やかな出鋼が常に行
える。 In particular, there is also a bottom blowing nozzle 1 near the tapping port 9.
1, it is possible to promote the dissolution of the scrap lump 12 that remains in the tap hole 9 portion. Therefore, even if a large scrap lump 12 is present in the tapping port 9 and blocks the tapping flow path, the scrap lump 12 can be concentrated by the effect of the stirring gas from the bottom blowing nozzle 11. promotes dissolution. In addition, the stirring effect by the other central nozzle 6 and the outer peripheral nozzle 7 can also be used to dissolve the scrap deposited on the tap hole 9 portion. As a result, in the steel tapping process, the steel tapping port 9 is not clogged with molten steel, and steel can always be tapped quickly.
更に、第６図及び第７図は本発明の第３実施例
を示す縦断面図と水平断面図である。本例におい
ても、第１図及び第２図の部材等に対応するもの
は同一の符番で指示し、その説明を省略した。た
だし、本例にあつては、出鋼口９を斜め上方に設
けるテイーポツト型の炉構造である点が第１実施
例と異なる。 Further, FIGS. 6 and 7 are a longitudinal sectional view and a horizontal sectional view showing a third embodiment of the present invention. In this example as well, parts corresponding to those in FIGS. 1 and 2 are indicated by the same reference numerals, and their explanations are omitted. However, this example differs from the first example in that it has a teapot type furnace structure in which the tapping port 9 is provided obliquely upward.
炉体１の側壁に設けられる出鋼口９は、第６図
の定常状態の姿勢で斜め上を向く開口軸線を持つ
ように形成され、外部には溶鋼を受鋼鍋に案内す
るガイド１３を設けている。また、出鋼口９の位
置は、溶鋼の最大レベルよりも下にあり、出鋼前
には溶鋼に浸漬された状態となる。なお、中心ノ
ズル６及び外周ノズル７は、第１実施例と同様に
ほぼ炉体１の中心とその周囲にそれぞれ配置され
ている。 The tapping port 9 provided on the side wall of the furnace body 1 is formed so as to have an opening axis pointing diagonally upward in the steady state position shown in FIG. It is set up. Further, the tapping port 9 is located below the maximum level of molten steel, and is immersed in molten steel before tapping. Note that the center nozzle 6 and the outer peripheral nozzle 7 are arranged approximately at the center of the furnace body 1 and around it, respectively, as in the first embodiment.
この第３実施例に示す電弧炉では、出鋼する場
合には、第６図において炉体１を反時計方向に傾
転させることにより、溶鋼を出鋼口９から排出す
る。このときの傾転動作においては、出鋼口９に
対する溶鋼のヘツドが一定となるようにし、受鋼
鍋への急激な溶鋼の落下を防止する。 In the electric arc furnace shown in the third embodiment, when tapping steel, molten steel is discharged from the tapping port 9 by tilting the furnace body 1 counterclockwise in FIG. In this tilting operation, the head of the molten steel relative to the tapping port 9 is kept constant to prevent the molten steel from dropping suddenly into the steel receiving ladle.
このような、炉体１の傾転によつて溶鋼を排出
するとき、溶鋼との比重差によりスラグは浮上し
溶鋼のみを排出することが可能である。したがつ
て、前記の第１及び第２の実施例と同様に、脱硫
処理後の溶鋼のみを出鋼口９から排出できる。 When molten steel is discharged by such tilting of the furnace body 1, the slag floats due to the difference in specific gravity with the molten steel, and only the molten steel can be discharged. Therefore, like the first and second embodiments described above, only the molten steel after the desulfurization treatment can be discharged from the tapping port 9.
なお、出鋼後の時点では、スラグを含む溶鋼の
一部を炉体１内に残留させる操作により、ノズル
寿命を長くできることも、前記の実施例と同様で
ある。 Note that, as in the above embodiment, the nozzle life can be extended by allowing a portion of the molten steel containing slag to remain in the furnace body 1 after tapping.
以上に説明したように、本発明においては、電
弧炉内での溶解工程と予め投入している脱硫剤に
よる脱硫処理を同時に進行させ、炉床に配置した
攪拌用ガスを供給するノズルを常に浸漬するよう
にスラグを含んだ溶鋼の一部を炉内に残留させる
ようにしている。したがつて、従来のように出鋼
時に脱硫する工程を必要とせず、溶解処理が短時
間で行える。また、スラグを含む溶鋼の一部を炉
内に残留させるので、受鋼鍋に出鋼した鋼の清浄
化が可能となり、しかも受鋼鍋の耐火物原単位を
削減できる。更に、攪拌用のガスを供給するノズ
ルは、炉内に残留する溶鋼内に常に浸漬されるた
め、出鋼時及び溶解時の急激は温度変化の影響を
避けることができ、ノズル寿命を向上させること
ができる。
As explained above, in the present invention, the melting process in the electric arc furnace and the desulfurization treatment using the desulfurization agent added in advance proceed simultaneously, and the nozzle for supplying stirring gas placed in the hearth is always immersed. A portion of the molten steel containing slag is left in the furnace. Therefore, the melting process can be carried out in a short time without requiring a desulfurization process during tapping as in the past. Furthermore, since a part of the molten steel containing slag remains in the furnace, the steel tapped into the steel receiving ladle can be cleaned, and the refractory unit consumption of the steel receiving ladle can be reduced. Furthermore, the nozzle that supplies the stirring gas is always immersed in the molten steel remaining in the furnace, so it can avoid the effects of sudden temperature changes during tapping and melting, which improves the nozzle life. be able to.
第１図及び第２図は本発明の第１実施例を示す
縦断面図と水平断面面図、第３図は中心ノズル及
び外周ノズルからの攪拌用ガス流量の比が浴の均
一混合時間及び炉壁部分での波打ち高さに与える
影響を示す。また、第４図及び第５図は本発明の
第２実施例を示す縦断面図と水平断面図、第６図
及び第７図は第３実施例を示す縦断面図と水平断
面図である。
1 and 2 are longitudinal and horizontal sectional views showing the first embodiment of the present invention, and FIG. 3 shows the ratio of the stirring gas flow rate from the center nozzle and the outer nozzle to the uniform mixing time of the bath and the horizontal sectional view. This figure shows the effect on the height of undulations on the furnace wall. Further, FIGS. 4 and 5 are a longitudinal sectional view and a horizontal sectional view showing a second embodiment of the present invention, and FIGS. 6 and 7 are a longitudinal sectional view and a horizontal sectional view showing a third embodiment. .
Claims (1)
拌を行なう電弧炉において、出鋼前の段階におい
て予め炉内に脱硫剤を投入し、前記底吹ノズルか
ら攪拌用ガスを吹き込んで装入原料を溶解すると
同時に脱硫処理し、更に脱硫後のスラグを含む溶
鋼の一部を炉内に残留させて出鋼工程を行うこと
を特徴とする電弧炉の操業方法。 ２ 溶解及び脱硫処理後の溶鋼の内、所期の溶鋼
量のほぼ1/10以上を炉内に残留させ、該残留溶鋼
に底吹ノズルを常に浸漬させることを特徴とする
特許請求の範囲第１項記載の電弧炉の操業方法。 ３ 炉体内の炉床をそのほぼ中央域が最も深い凹
状に形成すると共に攪拌用のガスを溶鋼内に吹き
込む底吹ノズルを該炉床に設け、前記底吹ノズル
が鋼浴中に常に浸漬されることが可能な高さに開
口を持つ出鋼口を設けたことを特徴とする電弧
炉。 ４ 前記出鋼口の近傍に攪拌用ガスを吹き込む底
吹ノズルを併設したことを特徴とする特許請求の
範囲第３項記載の電弧炉。[Scope of Claims] 1. In an electric arc furnace in which a bottom blowing nozzle is provided at the bottom of the electric arc furnace to stir the molten steel, a desulfurizing agent is previously introduced into the furnace at a stage before tapping, and the desulfurization agent is stirred from the bottom blowing nozzle. A method for operating an electric arc furnace, characterized in that a charged raw material is melted by blowing in a sacrificial gas and at the same time desulfurization is performed, and a part of the molten steel containing slag after desulfurization is left in the furnace to perform a steel tapping process. 2. Among the molten steel after melting and desulfurization treatment, approximately 1/10 or more of the intended amount of molten steel remains in the furnace, and the bottom blowing nozzle is always immersed in the residual molten steel. A method of operating an electric arc furnace according to item 1. 3. The hearth inside the furnace body is formed into a concave shape with the deepest part approximately at the center thereof, and a bottom blowing nozzle for blowing stirring gas into the molten steel is provided in the hearth, and the bottom blowing nozzle is always immersed in the steel bath. An electric arc furnace characterized by having a tapping port with an opening at a height that allows steel to be removed. 4. The electric arc furnace according to claim 3, further comprising a bottom blowing nozzle for blowing stirring gas into the vicinity of the tap opening.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62016899A JPS63183116A (en) | 1987-01-26 | 1987-01-26 | Method for operating arc furnace and arc furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62016899A JPS63183116A (en) | 1987-01-26 | 1987-01-26 | Method for operating arc furnace and arc furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63183116A JPS63183116A (en) | 1988-07-28 |
| JPH0478690B2 true JPH0478690B2 (en) | 1992-12-11 |
Family
ID=11928993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62016899A Granted JPS63183116A (en) | 1987-01-26 | 1987-01-26 | Method for operating arc furnace and arc furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63183116A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH04187985A (en) * | 1990-11-21 | 1992-07-06 | Nippon Steel Corp | Structure of bottom blow type electric furnace |
| JPH04103594U (en) * | 1991-02-08 | 1992-09-07 | 新日本製鐵株式会社 | Furnace body shape of electric furnace |
-
1987
- 1987-01-26 JP JP62016899A patent/JPS63183116A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63183116A (en) | 1988-07-28 |
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