JP3376185B2 - Vacuum refining apparatus and operation method thereof - Google Patents
Vacuum refining apparatus and operation method thereofInfo
- Publication number
- JP3376185B2 JP3376185B2 JP26216195A JP26216195A JP3376185B2 JP 3376185 B2 JP3376185 B2 JP 3376185B2 JP 26216195 A JP26216195 A JP 26216195A JP 26216195 A JP26216195 A JP 26216195A JP 3376185 B2 JP3376185 B2 JP 3376185B2
- Authority
- JP
- Japan
- Prior art keywords
- vacuum
- exhaust
- valve
- vacuum chamber
- exhaust system
- 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
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- Treatment Of Steel In Its Molten State (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は真空精錬装置及びそ
の運転方法に関し、例えば、溶鋼の脱ガス処理や合金添
加処理等の真空精錬を行う場合に適用して特に好適なも
のである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum refining apparatus and a method for operating the same, and is particularly suitable for application when performing vacuum refining such as degassing of molten steel or alloy addition.
【０００２】[0002]
【従来の技術】従来、溶鋼中の水素、酸素、窒素等のガ
ス成分や溶鋼中の炭素を除去する方法として、減圧下で
溶鋼を処理する真空精錬法が用いられている。また、そ
の真空精錬時に、溶鋼の成分調整のための合金添加処理
が行われるのが一般的である。2. Description of the Related Art Conventionally, a vacuum refining method for treating molten steel under reduced pressure has been used as a method for removing gas components such as hydrogen, oxygen and nitrogen in molten steel and carbon in molten steel. In addition, during the vacuum refining, it is general that an alloy addition treatment for adjusting the composition of the molten steel is performed.
【０００３】図９に、環流式真空脱ガス法又は循環脱ガ
ス法と呼ばれるＲＨ真空精錬法を実施するための従来の
装置を示す。FIG. 9 shows a conventional apparatus for carrying out an RH vacuum refining method called a reflux type vacuum degassing method or a circulating degassing method.
【０００４】このＲＨ真空精錬法では、図示の如く、２
本の浸漬管１０ａ、１０ｂを備えた真空槽１０を用い、
この真空槽１０の２本の浸漬管１０ａ、１０ｂを取鍋１
１内の溶鋼１２に浸漬する。そして、真空槽１０の内部
を真空排気し、浸漬管１０ａ、１０ｂを介して真空槽１
０内を循環する溶鋼の脱ガスを行う。In this RH vacuum refining method, as shown in FIG.
Using a vacuum chamber 10 equipped with book dipping tubes 10a, 10b,
Ladle 1 of two dipping tubes 10a, 10b of this vacuum chamber 10
It is immersed in the molten steel 12 in 1. Then, the inside of the vacuum chamber 10 is evacuated, and the vacuum chamber 1 is evacuated through the immersion tubes 10a and 10b.
Degassing of the molten steel circulating in 0 is performed.
【０００５】真空槽１０は、ガスクーラー１４及び連結
ダクト１５を介して排気ポンプに接続している。排気ポ
ンプは、一般に、多段エジェクターを備えたスチーム・
エジェクター・ポンプで構成される。The vacuum chamber 10 is connected to an exhaust pump via a gas cooler 14 and a connecting duct 15. Exhaust pumps are generally steam-equipped with multi-stage ejectors.
It consists of an ejector pump.
【０００６】本例の場合には、連結ダクト１５が３段の
ブースター１Ｂ〜３Ｂを介してコンデンサー１Ｃに接続
され、コンデンサー１Ｃとコンデンサー２Ｃとの間に遮
断弁である吸入弁４ＥＶを介してエジェクター４Ｅが設
けられている。また、コンデンサー２Ｃとコンデンサー
３Ｃとの間には、並列に２本のエジェクター５ＥA 、５
ＥB が設けられ、エジェクター５ＥB に吸入弁５ＥＶB
が設けられている。エジェクター５ＥA には吸入弁が設
けられていない。更に、コンデンサー３Ｃとアフター・
コンデンサーＡＣ1 との間には、やはり並列に２本のエ
ジェクター６ＥA 、６ＥB が吸入弁６ＥＶA 、６ＥＶB
を夫々介して設けられている。更に、コンデンサー１Ｃ
とアフター・コンデンサーＡＣ2 との間に吸入弁ＳＥＶ
を介してスターティング・エジェクターＳＥが設けられ
ている。コンデンサー１Ｃ〜３Ｃ及びアフター・コンデ
ンサーＡＣ1 、ＡＣ2 で凝縮された水蒸気はシールタン
クＳＬＴに集められる。In the case of this example, the connecting duct 15 is connected to the condenser 1C via the three-stage boosters 1B to 3B, and the ejector is provided between the condenser 1C and the condenser 2C via the intake valve 4EV which is a shutoff valve. 4E is provided. In addition, two ejectors 5E A and 5E 5 are connected in parallel between the condenser 2C and the condenser 3C.
E B is provided, the intake valve 5 EV B in ejector 5E B
Is provided. The ejector 5E A not provided with a suction valve. Furthermore, after the condenser 3C and
Two ejectors 6E A and 6E B are also provided in parallel between the condenser AC 1 and the intake valves 6EV A and 6EV B.
Are provided through each. Furthermore, condenser 1C
Intake valve SEV between the after condenser AC 2 and
A starting ejector SE is installed via. The water vapor condensed in the condensers 1C to 3C and the after condensers AC 1 and AC 2 is collected in the seal tank SLT.
【０００７】次に、この真空精錬装置の運転方法を説明
する。Next, a method of operating this vacuum refining apparatus will be described.
【０００８】まず、真空槽１０の浸漬管１０ａ、１０ｂ
を溶鋼１２に浸漬した後、排気ポンプを駆動して、真空
槽１０の内部を排気する。この時、図示は省略したが、
浸漬管１０ａ、１０ｂの一方にアルゴンガスを導入し、
エアー・リフト・ポンプの原理によって溶鋼を吸い上げ
る。これにより、溶鋼は真空槽１０の内部に流入飛散
し、脱ガスされた後、他方の浸漬管から自重により排出
される。First, the immersion tubes 10a and 10b of the vacuum chamber 10
After being immersed in the molten steel 12, the exhaust pump is driven to exhaust the inside of the vacuum chamber 10. At this time, although illustration is omitted,
Argon gas is introduced into one of the immersion tubes 10a and 10b,
It sucks molten steel by the principle of air lift pump. As a result, the molten steel flows into the vacuum chamber 10 and scatters, is degassed, and is then discharged from the other immersion pipe by its own weight.
【０００９】排気ポンプの駆動方法は、図３（ｂ）に示
すように、大気圧７６０Torrから１８０Torrの間は、ス
ターティング・エジェクターＳＥとエジェクター６
ＥA 、６ＥB のみを作動させ、真空度が１８０Torrにな
った時に、吸入弁ＳＥＶを閉じてスターティング・エジ
ェクターＳＥを停止し、新たにエジェクター５ＥA 、５
ＥB を作動させる。そして、真空度が１１５Torrになっ
た時に、エジェクター４Ｅを作動させ、更に、真空度が
５５Torrになった時に、エジェクター５ＥB 、６ＥB を
停止し、ブースター３Ｂを作動させる。この時、エジェ
クター５ＥB の吸入弁５ＥＶB は閉じるが、エジェクタ
ー６ＥB の吸入弁６ＥＶB は開けたままとする。更に、
真空度が５Torrになった時に、ブースター２Ｂを作動さ
せ、真空度が２Torrになった時に、ブースター１Ｂを作
動させる。As shown in FIG. 3 (b), the method of driving the exhaust pump is such that the starting ejector SE and the ejector 6 are operated between atmospheric pressure 760 Torr and 180 Torr.
When only E A and 6 E B are operated and the vacuum degree reaches 180 Torr, the suction valve SEV is closed and the starting ejector SE is stopped, and new ejectors 5E A and 5E
Activate E B. When the vacuum degree becomes 115 Torr, it actuates the ejector 4E, further, when the degree of vacuum becomes 55 Torr, ejector 5E B, stop 6E B, to actuate the booster 3B. At this time, the intake valve 5EV B of the ejector 5E B is closed, but the suction valve 6EV B of the ejector 6E B is kept open. Furthermore,
When the vacuum degree reaches 5 Torr, the booster 2B is activated, and when the vacuum degree reaches 2 Torr, the booster 1B is activated.
【００１０】以上に説明したのはＲＨ真空精錬法の場合
であるが、真空精錬法には、この他に、１本の浸漬管を
備えた真空槽を上下動させながら真空精錬を行うＤＨ真
空精錬法や、取鍋全体を真空槽の中に入れて真空精錬を
行う取鍋真空精錬法が良く知られている。これらの真空
精錬法でも、排気系は、上述した例とほぼ同様の構成で
ある。The above description has been made in the case of the RH vacuum refining method. In addition to this, in the vacuum refining method, a DH vacuum for performing vacuum refining while vertically moving a vacuum tank equipped with one dip tube is used. The refining method and the ladle vacuum refining method in which the entire ladle is placed in a vacuum tank for vacuum refining are well known. Also in these vacuum refining methods, the exhaust system has almost the same configuration as the above-mentioned example.
【００１１】[0011]
【発明が解決しようとする課題】以上に説明したような
従来の真空精錬装置では、真空精錬の開始時に真空槽と
排気系とを同時に排気する構成であるため、真空槽内が
脱ガスや脱炭に特に有効な例えば１０Torr以下の真空度
に達するまでの時間が比較的長く、その結果、脱ガスや
脱炭の効率が悪かった。In the conventional vacuum refining apparatus as described above, since the vacuum tank and the exhaust system are simultaneously evacuated at the start of vacuum refining, the inside of the vacuum tank is degassed or degassed. It takes a relatively long time to reach a degree of vacuum of, for example, 10 Torr or less, which is particularly effective for charcoal, and as a result, the efficiency of degassing and decarburization was poor.
【００１２】そこで、本発明の目的は、真空槽内を比較
的短時間で所望の高真空にすることができて脱ガスや脱
炭の効率の良い真空精錬装置及びその運転方法を提供す
ることである。[0012] Therefore, an object of the present invention is to provide a vacuum refining apparatus and a method of operating the vacuum refining apparatus, which can bring a desired high vacuum in a vacuum chamber in a relatively short time and which is highly efficient in degassing and decarburizing. Is.
【００１３】[0013]
【課題を解決するための手段】上述した課題を解決する
本発明の真空精錬装置は、真空槽と、多段エジェクター
を備えた排気ポンプと、前記排気ポンプを前記真空槽に
連結する連結ダクトと、前記連結ダクトと前記真空槽と
の間に設けられた第１の遮断弁と、前記排気ポンプの所
定のエジェクターを前記連結ダクト及び前記第１の遮断
弁を迂回して前記真空槽に連結する第１のバイパス管
と、前記第１のバイパス管に設けられた第２の遮断弁と
を有する。A vacuum refining apparatus of the present invention for solving the above-mentioned problems includes a vacuum tank, an exhaust pump equipped with a multistage ejector, and a connecting duct for connecting the exhaust pump to the vacuum tank. A first cutoff valve provided between the connection duct and the vacuum chamber, and a predetermined ejector of the exhaust pump that bypasses the connection duct and the first cutoff valve and is connected to the vacuum chamber It has one bypass pipe and a second shutoff valve provided in the first bypass pipe.
【００１４】本発明の一態様では、前記第１の遮断弁を
迂回して前記連結ダクトと前記真空槽とを互いに連結す
る第２のバイパス管と、前記第２のバイパス管に設けら
れた第３の遮断弁とを有する。In one aspect of the present invention, a second bypass pipe that bypasses the first shutoff valve and connects the connecting duct and the vacuum chamber to each other, and a second bypass pipe provided in the second bypass pipe are provided. 3 shutoff valves.
【００１５】また、本発明の真空精錬装置の運転方法
は、前記第１及び第２の遮断弁を閉じた状態で前記排気
ポンプを駆動して、前記第１の遮断弁よりも前記排気ポ
ンプ側の排気系を排気する第１の工程と、前記第２の遮
断弁を開いて、前記排気系と前記真空槽とを並行して排
気する第２の工程と、前記第２の遮断弁を閉じ、前記第
１の遮断弁を開いて、前記排気系と前記真空槽とを同時
に排気する第３の工程とを有する。Also, in the method of operating the vacuum refining apparatus of the present invention, the exhaust pump is driven with the first and second shutoff valves closed, and the exhaust pump side is closer to the exhaust pump than the first shutoff valve. First exhausting the exhaust system, opening the second shut-off valve, exhausting the exhaust system and the vacuum chamber in parallel, closing the second shut-off valve A third step of opening the first shutoff valve and simultaneously exhausting the exhaust system and the vacuum chamber.
【００１６】本発明の一態様による真空精錬装置の運転
方法は、前記第１、第２及び第３の遮断弁を閉じた状態
で前記排気ポンプを駆動して、前記第１の遮断弁よりも
前記排気ポンプ側の排気系を排気する第１の工程と、前
記第２の遮断弁を開いて、前記排気系と前記真空槽とを
並行して排気する第２の工程と、前記第２の遮断弁を閉
じ、前記第３の遮断弁を開いて、前記排気系と前記真空
槽とを互いに均圧化する第３の工程と、前記第１の遮断
弁を開いて、前記排気系と前記真空槽とを同時に排気す
る第４の工程とを有する。In a method of operating a vacuum refining apparatus according to one aspect of the present invention, the exhaust pump is driven with the first, second and third shutoff valves closed, and the vacuum shutoff valve is operated more than the first shutoff valve. A first step of exhausting the exhaust system on the exhaust pump side, a second step of opening the second shutoff valve to exhaust the exhaust system and the vacuum chamber in parallel, and the second step A third step of closing the shut-off valve and opening the third shut-off valve to equalize the pressure of the exhaust system and the vacuum chamber with each other; and opening the first shut-off valve to open the exhaust system and the And a fourth step of simultaneously evacuating the vacuum chamber.
【００１７】[0017]
【発明の実施の形態】以下、本発明を好ましい実施の形
態に従って具体的に説明する。BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be specifically described below according to preferred embodiments.
【００１８】図１に、本発明の第１の実施の形態による
真空精錬装置を示す。FIG. 1 shows a vacuum refining apparatus according to a first embodiment of the present invention.
【００１９】図１に示すように、この第１の実施の形態
においては、図９に示したと同様のＲＨ真空精錬法を実
施するための真空槽１０に接続されたガスクーラー１４
と連結ダクト１５との間に排気遮断弁ボックス１６が設
けられている。この排気遮断弁ボックス１６の中には排
気遮断弁１７が設けられ、この排気遮断弁１７により連
結ダクト１５が排気遮断弁ボックス１６の内部から遮断
されるようになっている。連結ダクト１５と排気遮断弁
ボックス１６の内部とは均圧用バイパス管１８で互いに
連絡しており、この均圧用バイパス管１８に遮断弁であ
る均圧弁１９が設けられている。As shown in FIG. 1, in this first embodiment, a gas cooler 14 connected to a vacuum chamber 10 for carrying out the RH vacuum refining method similar to that shown in FIG.
An exhaust cutoff valve box 16 is provided between the connection duct 15 and the connection duct 15. An exhaust cutoff valve 17 is provided in the exhaust cutoff valve box 16, and the connection duct 15 is cut off from the inside of the exhaust cutoff valve box 16 by the exhaust cutoff valve 17. The connection duct 15 and the inside of the exhaust cutoff valve box 16 are connected to each other by a pressure equalizing bypass pipe 18, and the pressure equalizing bypass pipe 18 is provided with a pressure equalizing valve 19 as a cutoff valve.
【００２０】また、排気ポンプのスターティング・エジ
ェクターＳＥと排気遮断弁ボックス１６との間に排気用
バイパス管２０が設けられている。この排気用バイパス
管２０には、２か所に遮断弁である吸入弁ＳＥＶ2 、Ｓ
ＥＶ3 が設けられ、排気ポンプのコンデンサー１Ｃとス
ターティング・エジェクターＳＥとの間に遮断弁である
吸入弁ＳＥＶ1 が設けられている。An exhaust bypass pipe 20 is provided between the starting ejector SE of the exhaust pump and the exhaust cutoff valve box 16. In this exhaust bypass pipe 20, intake valves SEV 2 and S, which are shut-off valves, are provided at two locations.
An EV 3 is provided, and an intake valve SEV 1, which is a shutoff valve, is provided between the condenser 1C of the exhaust pump and the starting ejector SE.
【００２１】更に、真空槽１０とガスクーラー１４との
間に、真空槽１０を大気圧に復圧するための復圧用エア
ーリーク弁１３が設けられている。また、真空槽１０に
は槽内真空計２１が設けられ、排気ポンプのブースター
１Ｂの直前の連結ダクト１５にはブースター前真空計２
２が設けられている。Further, between the vacuum chamber 10 and the gas cooler 14, there is provided an air leak valve 13 for pressure restoration for returning the pressure of the vacuum chamber 10 to the atmospheric pressure. Further, the vacuum tank 10 is provided with an in-tank vacuum gauge 21, and the pre-booster vacuum gauge 2 is installed in the connecting duct 15 immediately before the booster 1B of the exhaust pump.
Two are provided.
【００２２】その他の構成は、図９に示した従来の装置
と同様であり、図９に示した装置と対応する部分には同
一の符号を付してその詳細な説明を省略する。The other structure is similar to that of the conventional device shown in FIG. 9, and the parts corresponding to those of the device shown in FIG. 9 are designated by the same reference numerals and the detailed description thereof will be omitted.
【００２３】次に、この第１の実施の形態による真空精
錬装置の運転方法を図２のフローチャートに従い説明す
る。また、図３（ａ）に、この第１の実施の形態による
真空精錬装置の運転時の排気ポンプ各部の駆動状態を、
図４に、主要工程の概略図を夫々示す。Next, a method of operating the vacuum refining apparatus according to the first embodiment will be described with reference to the flow chart of FIG. Further, FIG. 3 (a) shows the driving state of each part of the exhaust pump during operation of the vacuum refining apparatus according to the first embodiment,
FIG. 4 shows a schematic diagram of each of the main steps.
【００２４】まず、ステップＳ１において、真空槽１０
の浸漬管１０ａ、１０ｂを溶鋼１２に浸漬する。First, in step S1, the vacuum chamber 10
The immersion pipes 10 a and 10 b of No. 1 are immersed in the molten steel 12.
【００２５】次に、ステップＳ２において、真空精錬を
開始する前に、吸入弁ＳＥＶ1 、４ＥＶ、５ＥＶB 、６
ＥＶA 、６ＥＶB を夫々開にし、排気遮断弁１７、均圧
弁１９及び吸入弁ＳＥＶ2 、ＳＥＶ3 を夫々閉じた状態
で、スターティング・エジェクターＳＥ及びエジェクタ
ー６ＥA 、６ＥB を夫々作動させ、図４（ａ）に示すよ
うに、排気遮断弁１７より排気ポンプ側の排気系のみを
事前排気する。Next, in step S2, the suction valves SEV 1 , 4EV, 5EV B , 6 are started before the vacuum refining is started.
EV A, the 6 EV B respectively to open, the exhaust cutoff valve 17, equalizing valve 19 and the intake valve SEV 2, SEV 3 in each closed, Starting ejector SE and ejector 6E A, a 6E B respectively is actuated, As shown in FIG. 4A, only the exhaust system on the exhaust pump side of the exhaust cutoff valve 17 is preexhausted.
【００２６】次に、ステップＳ３において、ブースター
前真空計２２により、ブースター１Ｂの直前の真空度が
１８０Torrに達したか否かを検出し、１８０Torrに達し
た時点で、次のステップＳ４に進む。Next, in step S3, the pre-booster vacuum gauge 22 detects whether or not the vacuum degree immediately before the booster 1B has reached 180 Torr, and when it reaches 180 Torr, the process proceeds to the next step S4.
【００２７】ステップＳ４では、吸入弁ＳＥＶ1 を閉
じ、次いで、ステップＳ５において、吸入弁ＳＥＶ2 、
ＳＥＶ3 を夫々開にし、エジェクター５ＥA 、５ＥB を
夫々作動させる。これにより、図４（ｂ）に示すよう
に、排気遮断弁１７より排気ポンプ側の排気系と真空槽
１０とが並行して排気される。即ち、真空槽１０がスタ
ーティング・エジェクターＳＥにより排気用バイパス管
２０を介して排気され、一方、排気系がエジェクター５
ＥA 、５ＥB 、６ＥA 、６ＥB により連結ダクト１５を
介して排気される。そして、この時、真空精錬が開始さ
れ、溶鋼の脱ガス及び脱炭が行われる。In step S4, the intake valve SEV 1 is closed, and then in step S5, the intake valve SEV 2 ,
Open SEV 3 respectively and operate ejectors 5E A and 5E B respectively . As a result, as shown in FIG. 4B, the exhaust system on the exhaust pump side of the exhaust cutoff valve 17 and the vacuum chamber 10 are exhausted in parallel. That is, the vacuum chamber 10 is evacuated by the starting ejector SE through the exhaust bypass pipe 20, while the evacuation system is the ejector 5
Exhausted through the connecting duct 15 by E A , 5 E B , 6 E A , 6 E B. Then, at this time, vacuum refining is started, and degassing and decarburization of the molten steel are performed.
【００２８】次に、ステップＳ６において、槽内真空計
２１により、真空槽１０内の真空度が１８０Torrに達し
たか否かを検出し、１８０Torrに達した時点で、次のス
テップＳ７に進む。Next, in step S6, the in-vessel vacuum gauge 21 detects whether or not the degree of vacuum in the vacuum chamber 10 has reached 180 Torr. When it reaches 180 Torr, the process proceeds to the next step S7.
【００２９】ステップＳ７では、吸入弁ＳＥＶ2 、ＳＥ
Ｖ3 を夫々閉じ、次いで、ステップＳ８において、均圧
弁１８を開にし、吸入弁４ＥＶを閉じて、図４（ｃ）に
示すように、真空槽１０と排気系との均圧処理を開始す
る。また、スターティング・エジェクターＳＥを停止す
る。In step S7, the intake valves SEV 2 and SE
V 3 is closed, then, in step S8, the pressure equalizing valve 18 is opened, the suction valve 4EV is closed, and as shown in FIG. 4C, the pressure equalizing process between the vacuum chamber 10 and the exhaust system is started. . Also, the starting ejector SE will be stopped.
【００３０】次のステップＳ９では、真空槽１０と排気
系との圧力差が５０Torr以下になったか否かを検出し、
圧力差が５０Torr以下になった時点で、次のステップＳ
１０に進む。In the next step S9, it is detected whether or not the pressure difference between the vacuum chamber 10 and the exhaust system is 50 Torr or less,
When the pressure difference falls below 50 Torr, the next step S
Go to 10.
【００３１】ステップＳ１０では、排気遮断弁１７を開
にし、次いで、ステップＳ１１において、吸入弁４ＥＶ
を開にし、エジェクター４Ｅを作動させる。これによ
り、真空槽１０と排気系とがエジェクター４Ｅ、５
ＥA 、５ＥB 、６ＥA 、６ＥB により連結ダクト１５を
介して同時に排気される。In step S10, the exhaust cutoff valve 17 is opened, and then in step S11, the intake valve 4EV is opened.
Open and operate the ejector 4E. As a result, the vacuum chamber 10 and the exhaust system are connected to the ejectors 4E and 5E.
E A , 5 E B , 6 E A , 6 E B are simultaneously exhausted through the connecting duct 15.
【００３２】以下は、ステップＳ１２において、従来と
ほぼ同様に真空精錬を続行し、真空度が５５Torrになっ
た時点で、エジェクター５ＥB 、６ＥB を停止し、ブー
スター３Ｂを作動させる。この時、エジェクター５ＥB
の吸入弁５ＥＶB は閉じるが、エジェクター６ＥB の吸
入弁６ＥＶB は開けたままとする。更に、真空度が５To
rrになった時点で、ブースター２Ｂを作動させ、真空度
が２Torrになった時に、ブースター１Ｂを作動させる。In the following, in step S12, the vacuum refining is continued almost in the same manner as the conventional one, and when the degree of vacuum reaches 55 Torr, the ejectors 5E B and 6E B are stopped and the booster 3B is operated. At this time, the ejector 5E B
It is of the intake valve 5EV B close, but the suction valve 6EV B of the ejector 6E B is kept open. Furthermore, the degree of vacuum is 5 To
When it becomes rr, the booster 2B is activated, and when the vacuum degree becomes 2 Torr, the booster 1B is activated.
【００３３】そして、ステップＳ１３では、真空精錬が
終了した時点で、均圧弁１８及び排気遮断弁１７を夫々
閉じ、排気系を真空保持した状態で処理を終了する。Then, in step S13, when the vacuum refining is completed, the pressure equalizing valve 18 and the exhaust cutoff valve 17 are closed respectively, and the process is completed while the exhaust system is kept in vacuum.
【００３４】従って、連続操業時の２回目以降の真空精
錬では、排気遮断弁１７より排気ポンプ側の排気系が或
る程度の減圧状態から排気を始められるので、排気の時
間を短縮することができる。Therefore, in the second and subsequent vacuum refining during continuous operation, the exhaust system on the exhaust pump side from the exhaust cutoff valve 17 can start exhausting from a decompressed state to some extent, so that the exhaust time can be shortened. it can.
【００３５】図５に、上に説明した運転時の時間と真空
度との関係を示す。FIG. 5 shows the relationship between the operating time and the degree of vacuum described above.
【００３６】まず、の段階では、真空精錬開始前に排
気系のみを事前排気する。そして、排気系の真空度が１
８０Torrに達した時点で、の段階に移り、真空精錬を
開始するとともに、排気系と真空槽とを並行して排気す
る。そして、真空槽の真空度が１８０Torrに達した時点
で、の段階に移り、排気系と真空槽とを均圧化する。
の時点で均圧化が達成された後は、排気系と真空槽と
を同時に排気しながら真空精錬を続行する。First, in the stage (1), only the exhaust system is pre-exhausted before the start of vacuum refining. And the vacuum degree of the exhaust system is 1
When the pressure reaches 80 Torr, the process moves to the step, vacuum refining is started, and the exhaust system and the vacuum chamber are exhausted in parallel. Then, when the degree of vacuum in the vacuum tank reaches 180 Torr, the process moves to the step of, and the exhaust system and the vacuum tank are pressure-equalized.
After the pressure equalization is achieved at the time point, the vacuum refining is continued while simultaneously exhausting the exhaust system and the vacuum chamber.
【００３７】図９において説明した従来の真空精錬装置
の運転時の排気ポンプ各部の駆動状態を図３（ｂ）に、
また、運転時間と真空度との関係を図５に併せて夫々示
すが、その従来のものと比較して、本発明の第１の実施
の形態による真空精錬装置及びその運転方法によれば、
排気ポンプ各部の駆動状態は殆ど変わっていないにもか
かわらず、例えば１０Torr以下の所望の真空度に達する
までの時間が大幅に短縮されていることが分かる。即
ち、真空槽内が所望の真空度に達するまでの時間は、排
気系のみを事前排気する段階から計っても大幅に短縮さ
れている。FIG. 3B shows the driving state of each part of the exhaust pump during the operation of the conventional vacuum refining apparatus described in FIG.
Further, the relationship between the operating time and the degree of vacuum is also shown in FIG. 5, respectively. Compared to the conventional one, according to the vacuum refining apparatus and the operating method thereof according to the first embodiment of the present invention,
It can be seen that, although the driving states of the respective parts of the exhaust pump have hardly changed, the time required to reach a desired vacuum degree of, for example, 10 Torr or less is significantly shortened. That is, the time required to reach the desired degree of vacuum in the vacuum chamber is greatly shortened even from the stage of pre-evacuating only the exhaust system.
【００３８】図６に、真空精錬による溶鋼中の炭素濃度
の経時変化を示す。図６において、横軸は処理時間
（分）、縦軸は炭素濃度（ｐｐｍ）を夫々示す。この図
６から分かるように、○で示す本発明の第１の実施の形
態による真空精錬では、実線で示す従来の真空精錬に比
べて、炭素濃度が急激に低下し、且つ、より低いレベル
にまで達している。即ち、本発明の構成により、短時間
での極低炭素鋼の安定溶製の可能となることが分かる。FIG. 6 shows changes with time in the carbon concentration in the molten steel by vacuum refining. In FIG. 6, the horizontal axis represents the processing time (minutes) and the vertical axis represents the carbon concentration (ppm). As can be seen from FIG. 6, in the vacuum refining according to the first embodiment of the present invention shown by ◯, the carbon concentration drastically decreases and reaches a lower level as compared with the conventional vacuum refining shown by the solid line. Has reached. That is, it is understood that the structure of the present invention enables stable melting of ultra low carbon steel in a short time.
【００３９】以上に説明した本発明の第１の実施の形態
によれば、主として連結ダクト１５からなる排気系と真
空槽１０との間に排気遮断弁１７を設け、且つ、排気用
バイパス管２０により排気ポンプのスターティング・エ
ジェクターＳＥと真空槽１０とを連結して真空槽１０を
直接排気可能としている。そして、真空精錬開始前に、
排気系のみを事前排気し、排気系が所定の真空度に達し
た時点で、通常は停止するスターティング・エジェクタ
ーＳＥにより真空槽１０を直接排気し、これにより、排
気系と真空槽１０とを並行して排気する。更に、真空槽
１０が所定の真空度に達した時点で、連結ダクト１５と
排気遮断弁ボックス１６との間に設けた均圧弁１９を介
し、排気系と真空槽１０とを均圧化する。しかる後、排
気遮断弁１７を開け、排気系と真空槽１０とを同時に排
気する。According to the first embodiment of the present invention described above, the exhaust cutoff valve 17 is provided between the exhaust system mainly composed of the connecting duct 15 and the vacuum chamber 10, and the exhaust bypass pipe 20 is provided. Thus, the starting ejector SE of the exhaust pump and the vacuum chamber 10 are connected to each other so that the vacuum chamber 10 can be directly exhausted. And before starting vacuum refining,
Only the exhaust system is pre-exhausted, and when the exhaust system reaches a predetermined vacuum degree, the vacuum chamber 10 is directly exhausted by the starting ejector SE which is normally stopped, whereby the exhaust system and the vacuum chamber 10 are separated. Evacuate in parallel. Further, when the vacuum tank 10 reaches a predetermined degree of vacuum, the exhaust system and the vacuum tank 10 are pressure-equalized via a pressure equalizing valve 19 provided between the connecting duct 15 and the exhaust cutoff valve box 16. After that, the exhaust cutoff valve 17 is opened, and the exhaust system and the vacuum chamber 10 are simultaneously exhausted.
【００４０】このような構成により、真空槽１０内を従
来よりも短時間で例えば１０Torr以下の所望の真空度に
することができ、脱ガス及び脱炭の効率を向上させるこ
とができて、例えば、短時間での極低炭素鋼の安定溶製
が可能となる。With such a structure, the inside of the vacuum chamber 10 can be made to have a desired vacuum degree of, for example, 10 Torr or less in a shorter time than in the conventional case, and the efficiency of degassing and decarburizing can be improved. Therefore, it becomes possible to stably manufacture ultra-low carbon steel in a short time.
【００４１】また、以上に説明した本発明の第１の実施
の形態においては、１回目の真空精錬終了後に、遮断弁
１７から吸入弁４ＥＶまでの間の排気系を高真空下で密
閉することができる。更に、排気用バイパス管２０内の
吸入弁ＳＥＶ2 とＳＥＶ3 との間を密閉することができ
る。従って、２回目以降の真空精錬時に、遮断弁１７以
降の排気系及び真空槽１０内を排気する時間を短縮でき
るという利点がある。In the first embodiment of the present invention described above, the exhaust system from the shutoff valve 17 to the intake valve 4EV is closed under high vacuum after the first vacuum refining is completed. You can Furthermore, the space between the intake valves SEV 2 and SEV 3 in the exhaust bypass pipe 20 can be sealed. Therefore, there is an advantage that the time for exhausting the exhaust system after the shutoff valve 17 and the inside of the vacuum chamber 10 can be shortened during the second and subsequent vacuum refining.
【００４２】次に、図７及び図８を参照して、本発明の
第２の実施の形態による真空精錬装置及びその運転方法
説明する。Next, a vacuum refining apparatus according to a second embodiment of the present invention and an operating method thereof will be described with reference to FIGS. 7 and 8.
【００４３】図７に示すように、この第２の実施の形態
による真空精錬装置は、均圧用バイパス管１８及び均圧
弁１９を設けていない以外は、図１で説明した第１の実
施の形態による真空精錬装置と実質的に同じ構成であ
る。従って、図１で説明した第１の実施の形態による真
空精錬装置と対応する部分には同一の符号を付してその
詳細な説明を省略する。As shown in FIG. 7, the vacuum refining apparatus according to the second embodiment is different from the first embodiment described in FIG. 1 except that the pressure equalizing bypass pipe 18 and the pressure equalizing valve 19 are not provided. The structure is substantially the same as that of the vacuum refining device according to. Therefore, the parts corresponding to those of the vacuum refining device according to the first embodiment described in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.
【００４４】この第２の実施の形態による真空精錬装置
の運転方法を、図８のフローチャートに従い説明する。A method of operating the vacuum refining apparatus according to the second embodiment will be described with reference to the flowchart of FIG.
【００４５】図８のフローチャートにおいて、ステップ
Ｓ１〜Ｓ７までは、図２で説明した第１の実施の形態に
よる運転方法のステップＳ１〜Ｓ７と同一であり、従っ
て、その詳細な説明を省略する。In the flowchart of FIG. 8, steps S1 to S7 are the same as steps S1 to S7 of the operating method according to the first embodiment described with reference to FIG. 2, and therefore detailed description thereof will be omitted.
【００４６】この第２の実施の形態においては、均圧用
バイパス管及び均圧弁を設けていないため、排気系と真
空槽１０との均圧処理は不要となる。即ち、並行排気に
よって真空槽１０内の真空度が１８０Torrになった時点
で、吸入弁ＳＥＶ2 、ＳＥＶ3 を閉じる（ステップＳ
７）。In the second embodiment, since the pressure equalizing bypass pipe and the pressure equalizing valve are not provided, the pressure equalizing process between the exhaust system and the vacuum chamber 10 becomes unnecessary. That is, the suction valves SEV 2 and SEV 3 are closed when the vacuum degree in the vacuum chamber 10 reaches 180 Torr due to the parallel exhaust (step S
7).
【００４７】次いで、スターティング・エジェクターＳ
Ｅを停止するとともに、排気遮断弁１７を開にし、エジ
ェクター４Ｅを作動させて、真空槽１０と排気系とをエ
ジェクター４Ｅ、５ＥA 、５ＥB 、６ＥA 、６ＥB によ
り連結ダクト１５を介して同時に排気する（ステップＳ
８′）。Next, the starting ejector S
While stopping E, the exhaust cutoff valve 17 is opened, the ejector 4E is operated, and the vacuum chamber 10 and the exhaust system are ejected by the ejectors 4E, 5E A , 5E B , 6E A , and 6E B via the connecting duct 15. Exhaust at the same time (step S
8 ').
【００４８】以下は、ステップＳ９′において、第１の
実施の形態と同様に真空精錬を続行し、次いで、ステッ
プＳ１０′において、真空精錬が終了した時点で、排気
遮断弁１７を閉じ、排気系を真空保持した状態で処理を
終了する。In the following, in step S9 ', vacuum refining is continued in the same manner as in the first embodiment, and then, in step S10', when the vacuum refining is completed, the exhaust cutoff valve 17 is closed and the exhaust system is closed. The process is completed while the vacuum is maintained.
【００４９】この第２の実施の形態においては、排気系
と真空槽１０との差圧が大きな状態で排気遮断弁１７を
開くため、排気遮断弁１７として、大きな推力を持った
遮断弁装置が必要となる。従って、上述した第１の実施
の形態の場合と比較して、排気遮断弁１７の設備費は高
くなるが、均圧処理を行わない分、処理時間を短縮でき
る（例えば、２０秒程度）という利点がある。In the second embodiment, since the exhaust cutoff valve 17 is opened in the state where the differential pressure between the exhaust system and the vacuum chamber 10 is large, a cutoff valve device having a large thrust is used as the exhaust cutoff valve 17. Will be needed. Therefore, although the equipment cost of the exhaust cutoff valve 17 is higher than that in the case of the first embodiment described above, the processing time can be shortened (for example, about 20 seconds) because the pressure equalizing process is not performed. There are advantages.
【００５０】以上、本発明をＲＨ真空精錬法に適用した
例を説明したが、本発明は、ＤＨ真空精錬法や取鍋真空
精錬法の場合にも殆ど同様にして適用が可能である。Although the example of applying the present invention to the RH vacuum refining method has been described above, the present invention can be applied to the DH vacuum refining method and the ladle vacuum refining method in almost the same manner.
【００５１】[0051]
【発明の効果】真空槽を所望の真空度にするまでの時間
が従来よりも短縮し、従って、脱ガスや脱炭等の真空精
錬の効率及び能力が向上する。しかも、排気ポンプ自体
の運転方法は、大きく変更する必要がない。更に、主と
して連結ダクトからなる排気系と、第１のバイパス管を
介した真空槽とを、各々排気ポンプの所定のエジェクタ
ーと接続することにより、排気系との真空槽とを並行し
て真空排気する構造、即ち相異なる２系統の排気機構に
よる並行した真空排気が可能となり、より短時間で効率
の良い真空精錬が実現する。EFFECTS OF THE INVENTION The time required to bring the vacuum chamber to a desired degree of vacuum is shortened as compared with the prior art, so that the efficiency and capacity of vacuum refining such as degassing and decarburizing are improved. Moreover, it is not necessary to change the operating method of the exhaust pump itself. Further, by connecting the exhaust system mainly consisting of the connecting duct and the vacuum tank via the first bypass pipe to the predetermined ejectors of the exhaust pump, the vacuum tank of the exhaust system and the vacuum tank are evacuated in parallel. The structure described above, that is, two different systems of evacuation mechanisms enable parallel vacuum evacuation, and efficient vacuum refining is realized in a shorter time.
【図１】本発明の第１の実施の形態による真空精錬装置
の構成を示す概略図である。FIG. 1 is a schematic diagram showing a configuration of a vacuum refining device according to a first embodiment of the present invention.
【図２】本発明の第１の実施の形態による真空精錬装置
の運転方法を示すフローチャートである。FIG. 2 is a flowchart showing an operating method of the vacuum refining device according to the first embodiment of the present invention.
【図３】本発明の第１の実施の形態による真空精錬装置
の運転方法及び従来の排気ポンプの運転パターンを示す
図である。FIG. 3 is a diagram showing an operation method of the vacuum refining apparatus according to the first embodiment of the present invention and an operation pattern of a conventional exhaust pump.
【図４】本発明の第１の実施の形態による真空精錬装置
の運転方法における主要工程を示す概略図である。FIG. 4 is a schematic diagram showing main steps in an operating method of the vacuum refining apparatus according to the first embodiment of the present invention.
【図５】本発明の第１の実施の形態による真空精錬装置
の運転方法及び従来の運転時間と真空度との関係を示す
グラフである。FIG. 5 is a graph showing the relationship between the operating method of the vacuum refining apparatus according to the first embodiment of the present invention and the conventional operating time and the degree of vacuum.
【図６】本発明及び従来の脱ガス処理における溶鋼中の
炭素濃度変化を示すグラフである。FIG. 6 is a graph showing changes in carbon concentration in molten steel in the degassing process of the present invention and the conventional one.
【図７】本発明の第２の実施の形態による真空精錬装置
の構成を示す概略図である。FIG. 7 is a schematic diagram showing a configuration of a vacuum refining device according to a second embodiment of the present invention.
【図８】本発明の第２の実施の形態による真空精錬装置
の運転方法を示すフローチャートである。FIG. 8 is a flowchart showing an operating method of the vacuum refining apparatus according to the second embodiment of the present invention.
【図９】従来の真空精錬装置の構成を示す概略図であ
る。FIG. 9 is a schematic diagram showing a configuration of a conventional vacuum refining device.
１０ 真空槽
１１ 取鍋
１２ 溶鋼
１３ 復圧用エアーリーク弁
１４ ガスクーラー
１５ 連結ダクト
１６ 排気遮断弁ボックス
１７ 排気遮断弁
１８ 均圧用バイパス管
１９ 均圧弁
２０ 排気用バイパス管
２１ 槽内真空計
２２ ブースター前真空計
１Ｂ〜３Ｂ ブースター
４Ｅ、５ＥA 、５ＥB 、６ＥA 、６ＥB エジェクター
ＳＥ スターティング・エジェクター
４ＥＶ、５ＥＶB 、６ＥＶA 、６ＥＶB 、ＳＥＶ1 〜Ｓ
ＥＶ3 吸入弁
１Ｃ〜３Ｃ コンデンサー
ＡＣ1 、ＡＣ2 アフター・コンデンサー
ＳＬＴ シールタンク10 Vacuum Tank 11 Ladle 12 Molten Steel 13 Air Pressure Return Valve 14 Gas Cooler 15 Connection Duct 16 Exhaust Cutoff Valve Box 17 Exhaust Cutoff Valve 18 Pressure Equalizing Bypass Pipe 19 Pressure Equalizing Valve 20 Exhaust Bypass Pipe 21 In-Tank Vacuum Gauge 22 In Front of Booster vacuum gauge 1B~3B booster 4E, 5E A, 5E B, 6E A, 6E B ejector SE starting ejector 4EV, 5EV B, 6EV A, 6EV B, SEV 1 ~S
EV 3 suction valve 1C ~ 3C condenser AC 1 , AC 2 after condenser SLT seal tank
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭62−174318（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) C21C 7/10 ─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-62-174318 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) C21C 7/10
Claims (4)
遮断弁と、 前記排気ポンプの所定のエジェクターを前記連結ダクト
及び前記第１の遮断弁を迂回して前記真空槽に連結する
第１のバイパス管と、 前記第１のバイパス管に設けられた第２の遮断弁とを有
することを特徴とする真空精錬装置。1. A vacuum chamber, an exhaust pump having a multistage ejector, a connecting duct connecting the exhaust pump to the vacuum chamber, and a first shutoff provided between the connecting duct and the vacuum chamber. A valve, a first bypass pipe that connects a predetermined ejector of the exhaust pump to the vacuum chamber by bypassing the connection duct and the first shutoff valve, and a second bypass pipe provided in the first bypass pipe. And a shutoff valve for the vacuum refining device.
クトと前記真空槽とを互いに連結する第２のバイパス管
と、前記第２のバイパス管に設けられた第３の遮断弁と
を有することを特徴とする請求項１に記載の真空精錬装
置。2. A second bypass pipe that bypasses the first cutoff valve and connects the connection duct and the vacuum chamber to each other; and a third cutoff valve provided in the second bypass pipe. The vacuum refining apparatus according to claim 1, further comprising:
方法において、 前記第１及び第２の遮断弁を閉じた状態で前記排気ポン
プを駆動して、前記第１の遮断弁よりも前記排気ポンプ
側の排気系を排気する第１の工程と、 前記第２の遮断弁を開いて、前記排気系と前記真空槽と
を並行して排気する第２の工程と、 前記第２の遮断弁を閉じ、前記第１の遮断弁を開いて、
前記排気系と前記真空槽とを同時に排気する第３の工程
とを有することを特徴とする真空精錬装置の運転方法。3. The method of operating a vacuum refining apparatus according to claim 1, wherein the exhaust pump is driven with the first and second shutoff valves closed, and the first shutoff valve is operated more than the first shutoff valve. A first step of exhausting the exhaust system on the exhaust pump side, a second step of opening the second shutoff valve to exhaust the exhaust system and the vacuum chamber in parallel, the second shutoff Close the valve, open the first shutoff valve,
A method of operating a vacuum refining apparatus, comprising a third step of simultaneously exhausting the exhaust system and the vacuum chamber.
方法において、 前記第１、第２及び第３の遮断弁を閉じた状態で前記排
気ポンプを駆動して、前記第１の遮断弁よりも前記排気
ポンプ側の排気系を排気する第１の工程と、 前記第２の遮断弁を開いて、前記排気系と前記真空槽と
を並行して排気する第２の工程と、 前記第２の遮断弁を閉じ、前記第３の遮断弁を開いて、
前記排気系と前記真空槽とを互いに均圧化する第３の工
程と、 前記第１の遮断弁を開いて、前記排気系と前記真空槽と
を同時に排気する第４の工程とを有することを特徴とす
る真空精錬装置の運転方法。4. The method of operating a vacuum refining apparatus according to claim 2, wherein the exhaust pump is driven with the first, second and third shutoff valves closed to drive the first shutoff valve. A first step of exhausting the exhaust system on the side of the exhaust pump, a second step of opening the second shutoff valve to exhaust the exhaust system and the vacuum chamber in parallel, Closing the second shutoff valve and opening the third shutoff valve,
A third step of equalizing the pressure of the exhaust system and the vacuum tank with each other; and a fourth step of opening the first shutoff valve to simultaneously exhaust the exhaust system and the vacuum tank And a method for operating a vacuum refining apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26216195A JP3376185B2 (en) | 1995-09-14 | 1995-09-14 | Vacuum refining apparatus and operation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP26216195A JP3376185B2 (en) | 1995-09-14 | 1995-09-14 | Vacuum refining apparatus and operation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0978121A JPH0978121A (en) | 1997-03-25 |
| JP3376185B2 true JP3376185B2 (en) | 2003-02-10 |
Family
ID=17371917
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP26216195A Expired - Lifetime JP3376185B2 (en) | 1995-09-14 | 1995-09-14 | Vacuum refining apparatus and operation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3376185B2 (en) |
-
1995
- 1995-09-14 JP JP26216195A patent/JP3376185B2/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0978121A (en) | 1997-03-25 |
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