JP3289607B2 - Lower tank structure of vacuum degassing tank - Google Patents
Lower tank structure of vacuum degassing tankInfo
- Publication number
- JP3289607B2 JP3289607B2 JP19867096A JP19867096A JP3289607B2 JP 3289607 B2 JP3289607 B2 JP 3289607B2 JP 19867096 A JP19867096 A JP 19867096A JP 19867096 A JP19867096 A JP 19867096A JP 3289607 B2 JP3289607 B2 JP 3289607B2
- Authority
- JP
- Japan
- Prior art keywords
- tank
- lower tank
- vacuum degassing
- steel
- molten 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 - Fee Related
Links
Landscapes
- Treatment Of Steel In Its Molten State (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、下部槽底面の鉄板
が変形し難く、浸漬管の取付け管が、”ハの字”に変形
するのを防止する真空脱ガス槽の下部槽構造に関するも
のである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lower tank structure of a vacuum degassing tank for preventing an iron plate on a bottom of a lower tank from being easily deformed and preventing a mounting pipe of a dip tube from being deformed into a "C" shape. It is.
【０００２】[0002]
【従来の技術】真空脱ガス法には、ＲＨ法、ＤＨ法があ
る。ＲＨ法もＤＨ法も、溶鋼の吸い上げ機構が違うだけ
で、溶鋼を真空槽内に吸い上げ真空精錬を行う点は全く
同一であるので、ここでは、ＲＨ法について説明する。
図５は、ＲＨ真空脱ガス装置の概要図である。真空脱ガ
ス槽（以後、脱ガス槽という。）１は、その下部に２本
の浸漬管３ａ，３ｂを有し、この２本の浸漬管３ａ，３
ｂを溶鋼鍋４の溶鋼５内に浸漬し、脱ガス槽１の上部に
形成された排気管７から脱ガス槽１内部のガスを吸引し
て、脱ガス槽１を真空にする。この後、大気圧との差圧
を利用して溶鋼５を浸漬管３ａを介して脱ガス槽１内に
吸い上げるとともに、浸漬管３ａから不活性ガスである
ＡｒガスＧを吹込む。これにより、溶鋼５を浸漬管３ａ
→脱ガス槽１→浸漬管３ｂの経路で矢印２の向きに循環
させ、前記ＡｒガスＧにより溶鋼５を脱ガス槽１の内部
で攪拌、混合させ、溶鋼５の脱炭、脱ガス、脱酸および
介在物の浮上を行わせて、溶鋼の精錬を実施するもので
ある。2. Description of the Related Art As a vacuum degassing method, there are an RH method and a DH method. Both the RH method and the DH method are exactly the same in that the molten steel is sucked into a vacuum chamber and vacuum refining is performed, except that the molten steel suction mechanism is different. Therefore, the RH method will be described here.
FIG. 5 is a schematic diagram of an RH vacuum degassing device. The vacuum degassing tank (hereinafter, referred to as a degassing tank) 1 has two immersion tubes 3a and 3b at a lower portion thereof, and the two immersion tubes 3a and 3b.
b is immersed in the molten steel 5 of the molten steel pot 4, and the gas inside the degassing tank 1 is sucked from the exhaust pipe 7 formed at the upper part of the degassing tank 1 to make the degassing tank 1 vacuum. Thereafter, the molten steel 5 is sucked into the degassing tank 1 through the immersion pipe 3a using the pressure difference from the atmospheric pressure, and the inert gas Ar gas G is blown from the immersion pipe 3a. Thereby, the molten steel 5 is immersed in the immersion pipe 3a.
→ Degassing tank 1 → Circulate in the direction of arrow 2 in the route of immersion pipe 3b, and agitate and mix molten steel 5 inside degassing tank 1 with Ar gas G to decarbonize, degas, and degas molten steel 5. The refining of molten steel is performed by causing the acid and inclusions to float.
【０００３】図３および図４は、ＲＨ法に使用している
従来の脱ガス槽１の縦断面図および下面図である。脱ガ
ス槽１は、上蓋１ａ、胴部槽１ｂおよび下部槽１ｃから
構成され、下部槽底部に溶鋼を槽内に取り入れ、また排
出する２本の浸漬管８ａ，８ｂを有している。そして、
上蓋１ａ、胴部槽１ｂおよび下部槽１ｃは、それぞれの
間をフランジＦで接合されている。また、これら上蓋１
ａ、胴部槽１ｂおよび下部槽１ｃは、それぞれ、鉄皮１
０の内側に所定の厚さで不定形耐火物および耐火煉瓦１
１を内張りした構造である。この内、下部槽１ｃは、そ
の下面に浸漬管取付け管９ａ，９ｂが形成されており、
これらに浸漬管８ａ，８ｂが、フランジＦ3 により接合
されている。浸漬管８ａ，８ｂは、管の外側に不定形耐
火物層を形成し、管の内側に定形耐火煉瓦を内張りした
構造であり、管の一端にフランジが取付けられている。FIGS. 3 and 4 are a vertical sectional view and a bottom view of a conventional degassing tank 1 used in the RH method. The degassing tank 1 includes an upper lid 1a, a body tank 1b, and a lower tank 1c, and has two immersion pipes 8a, 8b at the bottom of the lower tank for taking in and discharging molten steel into the tank. And
The upper lid 1a, the body tank 1b, and the lower tank 1c are joined to each other by a flange F. In addition, these upper lids 1
a, the body tank 1b and the lower tank 1c
0 and an irregular shaped refractory and refractory brick 1 with a predetermined thickness
1 is lined. Of these, the lower tank 1c has immersion pipe mounting pipes 9a and 9b formed on the lower surface thereof.
These dip tube 8a, 8b are joined by a flange F 3. The immersion pipes 8a and 8b have a structure in which an irregular refractory layer is formed on the outside of the pipe, and a fixed refractory brick is lined on the inside of the pipe, and a flange is attached to one end of the pipe.
【０００４】なお、浸漬管８ｂには、図示されていない
が、Ａｒガス吹込みパイプが複数埋設されており、浸漬
管８ｂの内部を上昇する溶鋼中にＡｒガスを吹込むこと
ができる。Although not shown, a plurality of Ar gas injection pipes are buried in the immersion pipe 8b, and Ar gas can be injected into molten steel rising inside the immersion pipe 8b.
【０００５】このような構造の脱ガス槽１において、溶
鋼の脱ガス工程では、下部槽１ｃに、上述したように、
高温の溶鋼がＡｒガスの気泡により激しく攪拌されつ
つ、循環する。脱ガスが終了すると、溶鋼の無い状態と
なる。脱ガス工程において、下部槽１ｃの鉄皮１０は、
直下にある溶鋼の輻射熱により高温に曝されるととも
に、脱ガス槽の真空引きによりおよそ１．０Torrの負圧
がかかる。これにより、特に、浸漬管８ａ，８ｂを接続
するための開口を有する下部槽１ｃの底部鉄皮１０は、
時間とともに変形し、終には、浸漬管の取付け管が”ハ
の字”に変形し、槽内部における溶鋼の攪拌等に支障を
きたす。In the degassing tank 1 having such a structure, in the step of degassing molten steel, as described above,
The high-temperature molten steel circulates while being vigorously stirred by the bubbles of Ar gas. When degassing is completed, there is no molten steel. In the degassing step, the steel shell 10 of the lower tank 1c is
While being exposed to high temperature by the radiant heat of the molten steel immediately below, a negative pressure of about 1.0 Torr is applied by evacuation of the degassing tank. Thereby, in particular, the bottom iron shell 10 of the lower tank 1c having an opening for connecting the immersion pipes 8a and 8b,
It deforms with time, and finally the mounting pipe of the immersion pipe deforms into a "C" shape, which hinders the stirring of molten steel inside the tank.
【０００６】これを防止するために、下部槽１ｃの底
部鉄皮１０に補強リブを設けたり、防熱板の取付け、
エア冷却を行っていた。In order to prevent this, a reinforcing rib is provided on the bottom steel shell 10 of the lower tank 1c, or a heat insulating plate is attached.
Air cooling was being performed.
【０００７】[0007]
【発明が解決しようとする課題】輻射熱により熱せられ
たときのクリープを考慮すると、底部鉄皮の厚みは少な
くとも１１０ｍｍは必要であるが、底部鉄皮１０をこの
ように厚くすることは、製作コストが嵩み、経済的に不
利である。このため、底部鉄皮１０は、４０ｍｍ以下、
好ましくは、３２ｍｍ以下にし、補強リブを設けること
にした。In consideration of creep when heated by radiant heat, the thickness of the bottom steel is required to be at least 110 mm. Is bulky and economically disadvantageous. For this reason, the bottom iron shell 10 is 40 mm or less,
Preferably, it is set to 32 mm or less, and a reinforcing rib is provided.
【０００８】図６および図７は、補強リブを設けた例を
示したものである。この例では、内径；３２００ｍｍ，
深さ２６７７ｍｍ、底部鉄皮１０の厚さ；３２ｍｍの下
部槽１ｃの下面鉄板に、厚さ２５ｍｍ，高さ１５０ｍｍ
の補強リブ１３を取り付けた。そして、図８に示すよう
に、二つの下部槽について、深さ方向の変形量Δｈと深
さ方向の凹凸量Δｈc の経時変化を調べた。この結果、
破線で示すように下部槽の中心を挟んで内部方向に凸の
二つの山と中心にできる外部方向に凹の谷からなる変形
が発生し、第１の下部槽では、１０２００チャージで、
Δｈ＝−７０ｍｍ（深さに対する変形率；２．６％）、
Δｈc ＝７２ｍｍ、第２の下部槽では、１０９００チャ
ージで、Δｈ＝−９２ｍｍ（深さに対する変形率；３．
４％）、Δｈc ＝９５ｍｍとなり、どちらも使用限界
（使用限界；Δｈ＝５０ｍｍ）を越えた。FIGS. 6 and 7 show examples in which reinforcing ribs are provided. In this example, the inner diameter is 3200 mm,
A depth of 2677 mm, a thickness of the bottom steel shell 10; a thickness of 25 mm and a height of 150 mm on a lower steel plate of the lower tank 1 c of 32 mm.
Was attached. Then, as shown in FIG. 8, the two lower tanks were examined the time course of the deformation amount Delta] h and depth of the irregularity Delta] h c in the depth direction. As a result,
As shown by the broken line, a deformation consisting of two inwardly convex ridges and an outwardly concave valley formed at the center with respect to the center of the lower tank occurs, and in the first lower tank, 10200 charges,
Δh = −70 mm (deformation ratio to depth; 2.6%),
Δh c = 72 mm, and in the second lower tank, at 10900 charges, Δh = −92 mm (deformation ratio to depth;
4%), Δh c = 95 mm, and both exceeded the usage limit (use limit; Δh = 50 mm).
【０００９】このようなリブを取り付ける補強において
も、使用限界を越える変形が発生するため、その取付け
部に応力を集中させることになり、溶接欠陥等があると
そのために亀裂が入るという欠点があった。[0009] Even in the reinforcement for mounting such ribs, deformation exceeding the service limit is generated, so that stress is concentrated on the mounting portion, and there is a defect that cracks are caused due to welding defects and the like. Was.
【００１０】本発明は、補強リブを取り付けなくとも、
変形の少ない真空脱ガス槽の下部槽構造を提供すること
を目的とする。According to the present invention, even if a reinforcing rib is not attached,
An object is to provide a lower tank structure of a vacuum degassing tank with less deformation.
【００１１】[0011]
【課題を解決するための手段】本発明は、上記目的を、
上蓋、胴部槽および下部槽から構成され、下部槽底部に
溶鋼を槽内に取り入れる浸漬管を有する真空脱ガス槽の
下部槽構造において、下部槽の下部中央部を外側に突出
した凸曲面に形成した真空脱ガス槽の下部槽構造により
達成する。SUMMARY OF THE INVENTION The present invention provides the above object,
In the lower tank structure of a vacuum degassing tank that is composed of an upper lid, a body tank, and a lower tank, and has a dip tube for taking molten steel into the tank at the bottom of the lower tank, the lower central part of the lower tank has a convex curved surface that protrudes outward. This is achieved by the lower tank structure of the formed vacuum degassing tank.
【００１２】「作用」下部槽の下部を外側に突出した凸
曲面で形成してあるから、平底に比して内側向きの応力
に対して変形抵抗が大きいので、変形量が極めて少な
い。[Operation] Since the lower portion of the lower tank is formed of a convex curved surface protruding outward, the deformation resistance is extremely small with respect to the stress directed inward as compared with the flat bottom, so that the amount of deformation is extremely small.
【００１３】補強リブを取付ける必要がないから、補強
リブの取付けに起因する亀裂入りという致命的事故を防
止できる。Since there is no need to attach the reinforcing ribs, it is possible to prevent a fatal accident such as cracking due to the attachment of the reinforcing ribs.
【００１４】使用する鉄板厚さをより薄くできる。The thickness of the iron plate used can be reduced.
【００１５】[0015]
【発明の実施の形態】本発明の実施の形態を図面に基づ
き以下に説明する。図１は、本発明のＲＨ法に使用する
真空脱ガス槽の下部槽の鉄皮構造の縦断面図、図２は、
本発明のＲＨ法に使用する真空脱ガス槽の下部槽の鉄皮
構造の下面図である。１０ａは下部槽１ｃの側部鉄皮、
１０ｂは下部槽１ｃの底部鉄皮、９ａ、９ｂは浸漬管取
付け管である。Ｆt は下部槽１ｃを胴部槽に接合するた
めのフランジ、Ｆb は浸漬管を取り付けるために浸漬管
取付け管９ａ、９ｂの下端に取付けたフランジ、２０は
下部槽１ｃの吊り金具である。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a steel shell structure of a lower tank of a vacuum degassing tank used in the RH method of the present invention, and FIG.
It is a bottom view of the iron shell structure of the lower tank of the vacuum degassing tank used for the RH method of the present invention. 10a is a side skin of the lower tank 1c,
Reference numeral 10b denotes a bottom steel shell of the lower tank 1c, and reference numerals 9a and 9b denote submerged tube mounting tubes. F t flanges fitted with bottom tank 1c flange for joining to the torso tank, F b is the dip tube connecting pipe 9a for attaching a dip tube, the lower end of 9b, 20 is the lifting lugs of the lower tank 1c .
【００１６】以上の構造の下部槽１ｃにおいて、底部鉄
皮１０ｂは、小半径Ｒ1 の中央部１０ｂ1 とより大半径
Ｒ2 の外周部分１０ｂ2 の二つの球面を組み合わせて形
成されている。なお、外周部分１０ｂ2 を球面とする代
わりに頭切円錐体面あるいは、２次曲線の回転面として
もよい。[0016] In the lower tank 1c of the above structure, the bottom furnace shell 10b are formed by combining two spherical outer circumferential portion 10b 2 of the central portion 10b 1 and the larger radius R 2 of the small radius R 1. Incidentally, the outer peripheral portion 10b 2 Atamasetsu cone body surface or instead of a spherical surface may be a rotating surface of the quadratic curve.
【００１７】[0017]
【実施例】図１に示す鉄皮形状で、上部内径；３２００
ｍｍ、中心部深さ；２４３０ｍｍ、底部鉄皮１０ｂの中
央部１０ｂ1 の球半径；６０００ｍｍ、外周分１０ｂ1
の球半径；６０４５ｍｍとし、側部鉄皮１０ａの厚さ；
２５ｍｍ、底部鉄皮１０ｂの厚さ；４５ｍｍとした下部
槽１ｃを製作して、操業テストを行った。１３，０００
チャージ使用したが、浸漬管の取付け管が ”ハの字”
に変形することもなく、また深さ方向変形量Δｈが、６
ｍｍと少なく、底板鉄皮をリブで補強した従来の下部槽
の寿命の８倍の延命が可能であることが分かった。DESCRIPTION OF THE PREFERRED EMBODIMENTS The steel shell shown in FIG.
mm, central part depth: 2430 mm, spherical radius of central part 10 b 1 of bottom steel shell 10 b; 6000 mm, outer peripheral part 10 b 1
Sphere radius; 6045 mm; thickness of side steel shell 10a;
An operation test was conducted by manufacturing a lower tank 1c having a thickness of 25 mm and a thickness of the bottom iron shell 10b of 45 mm. 13,000
I used the charge, but the mounting pipe of the immersion pipe was "C"
And the depth direction deformation amount Δh is 6
mm, which is 8 times longer than that of the conventional lower tank whose bottom plate is reinforced with ribs.
【００１８】[0018]
【発明の効果】本発明によれば、下部槽の下部を外側に
突出した球面で形成してあるから、底板鉄皮をリブで補
強した従来の下部槽に比べ大幅な寿命延長ができる。ま
た、補強リブを取付ける必要がないから、補強リブの取
付けに起因する亀裂入りという致命的事故を防止でき
る。さらにまた、従来の下部槽の寿命でよければ、使用
する鉄板厚さをより薄くできる。According to the present invention, since the lower portion of the lower tank is formed of a spherical surface protruding outward, the service life can be greatly extended as compared with the conventional lower tank in which the steel plate of the bottom plate is reinforced with ribs. Moreover, since it is not necessary to attach the reinforcing ribs, it is possible to prevent a fatal accident such as cracking due to the attachment of the reinforcing ribs. Furthermore, if the life of the conventional lower tank is sufficient, the thickness of the iron plate used can be reduced.
【００１９】さらにまた、浸漬管の取付け管が”ハの
字”に変形することもなく、耐火物の施工も容易とな
る。また、下部槽の鉄皮切取り補修も不要となる。Further, the mounting pipe of the immersion pipe does not deform into a "C" shape, and the construction of the refractory is facilitated. Also, it is not necessary to cut and repair the steel skin of the lower tank.
【図１】本発明のＲＨ法に使用する真空脱ガス槽の下部
槽の鉄皮構造の縦断面図である。FIG. 1 is a longitudinal sectional view of a steel shell structure of a lower tank of a vacuum degassing tank used in the RH method of the present invention.
【図２】本発明のＲＨ法に使用する真空脱ガス槽の下部
槽の鉄皮構造の下面図である。FIG. 2 is a bottom view of a steel shell structure of a lower tank of a vacuum degassing tank used in the RH method of the present invention.
【図３】ＲＨ法に使用している従来の脱ガス槽の縦断面
図である。FIG. 3 is a longitudinal sectional view of a conventional degassing tank used for the RH method.
【図４】ＲＨ法に使用している従来の脱ガス槽の下面図
である。FIG. 4 is a bottom view of a conventional degassing tank used for the RH method.
【図５】ＲＨ真空脱ガス装置の概要図である。FIG. 5 is a schematic diagram of an RH vacuum degassing device.
【図６】底板鉄皮をリブで補強した平底型下部槽の縦断
面図である。FIG. 6 is a longitudinal sectional view of a flat bottom type lower tank in which a bottom plate steel is reinforced with ribs.
【図７】底板鉄皮をリブで補強した平底型下部槽の下面
図である。FIG. 7 is a bottom view of a flat bottom type lower tank in which a bottom plate iron skin is reinforced with ribs.
【図８】底板鉄皮をリブで補強した平底型下部槽の底板
鉄皮の変形量を説明する縦断面図である。FIG. 8 is a longitudinal sectional view for explaining the deformation of the bottom plate steel of the flat bottom type lower tank in which the bottom plate steel is reinforced with ribs.
１ 脱ガス槽 １ａ 上蓋 １ｂ 胴部槽 １ｃ 下部槽 ３ａ，３ｂ 浸漬管 ４ 溶鋼鍋 ５ 溶鋼 ９ａ，９ｂ 浸漬管取付け管 １０ａ 側部鉄皮 １０ｂ 底部鉄皮 １０ｂ1 底部鉄皮の中央部（小半径の球面） １０ｂ2 底部鉄皮の外周部（より大半径の球面） Ｇ Ａｒガス Ｆt フランジ Ｆb フランジ1 degassing tank 1a upper lid 1b barrel tank 1c lower tank 3a, 3b dip tube 4 ladle 5 molten steel 9a, the center portion of 9b dip tube connecting pipe 10a side steel shell 10b bottom steel shell 10b 1 bottom furnace shell (minor radius 10b 2 Peripheral part of the bottom steel (larger spherical surface) G Ar gas Ft flange Fb flange
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 平７−316632（ＪＰ，Ａ) 特開 昭63−93817（ＪＰ，Ａ) 特開 平７−268444（ＪＰ，Ａ) 実開 昭59−80450（ＪＰ，Ｕ) (58)調査した分野(Int.Cl.7，ＤＢ名) C21C 7/10 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-316632 (JP, A) JP-A-63-93817 (JP, A) JP-A-7-268444 (JP, A) 80450 (JP, U) (58) Field surveyed (Int. Cl. 7 , DB name) C21C 7/10
Claims (1)
れ、下部槽底部に溶鋼を槽内に取り入れる浸漬管を有す
る真空脱ガス槽の下部槽構造において、下部槽の下部中
央部を外側に突出した凸曲面に形成したことを特徴とす
る真空脱ガス槽の下部槽構造。1. A lower tank structure of a vacuum degassing tank comprising an upper lid, a body tank, and a lower tank, and having a dip tube for introducing molten steel into the tank at the bottom of the lower tank. A lower tank structure of a vacuum degassing tank formed on a protruding convex surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19867096A JP3289607B2 (en) | 1996-07-29 | 1996-07-29 | Lower tank structure of vacuum degassing tank |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19867096A JP3289607B2 (en) | 1996-07-29 | 1996-07-29 | Lower tank structure of vacuum degassing tank |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH1046228A JPH1046228A (en) | 1998-02-17 |
| JP3289607B2 true JP3289607B2 (en) | 2002-06-10 |
Family
ID=16395100
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19867096A Expired - Fee Related JP3289607B2 (en) | 1996-07-29 | 1996-07-29 | Lower tank structure of vacuum degassing tank |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3289607B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009184779A (en) * | 2008-02-06 | 2009-08-20 | Jfe Steel Corp | Suspension device having automatic slinging function |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP7416107B2 (en) * | 2021-03-31 | 2024-01-17 | Ｊｆｅスチール株式会社 | Lower tank structure of RH vacuum degassing tank and RH vacuum degassing equipment |
-
1996
- 1996-07-29 JP JP19867096A patent/JP3289607B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2009184779A (en) * | 2008-02-06 | 2009-08-20 | Jfe Steel Corp | Suspension device having automatic slinging function |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH1046228A (en) | 1998-02-17 |
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