JP2000192119A - Method for blowing auxiliary fuel into blast furnace - Google Patents
Method for blowing auxiliary fuel into blast furnaceInfo
- Publication number
- JP2000192119A JP2000192119A JP10370425A JP37042598A JP2000192119A JP 2000192119 A JP2000192119 A JP 2000192119A JP 10370425 A JP10370425 A JP 10370425A JP 37042598 A JP37042598 A JP 37042598A JP 2000192119 A JP2000192119 A JP 2000192119A
- Authority
- JP
- Japan
- Prior art keywords
- tuyere
- auxiliary fuel
- blast furnace
- blowing
- pulverized coal
- 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.)
- Granted
Links
Landscapes
- Manufacture Of Iron (AREA)
- Blast Furnaces (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、高炉への補助燃料
吹込み方法に関するものである。The present invention relates to a method for injecting auxiliary fuel into a blast furnace.
【０００２】[0002]
【従来の技術】周知のように従来、高炉では、鉄鉱石
（ペレット、焼結鉱を含む）、コークス、石灰石などを
上部から装入する一方、下部の羽口から高温の空気を供
給することで、コークスを燃料（熱源）及び還元剤とし
て鉄鉱石を還元、溶解し、銑鉄の製造がなされてきた
が、その後、製造コストの高いコークスの使用量を低減
するため、またコークス炉の老朽化対策としてコークス
炉の稼働率を軽減するため、等の理由から、コークスに
換わる燃料として高炉羽口から補助燃料を吹込む高炉へ
の補助燃料吹込み操業方法が広く実施されるようになっ
てきた。2. Description of the Related Art As is well known, conventionally, in a blast furnace, iron ore (including pellets and sintered ore), coke, limestone and the like are charged from an upper portion, and high-temperature air is supplied from a lower tuyere. Iron ore was reduced and melted using coke as a fuel (heat source) and reducing agent, and pig iron was manufactured. However, in order to reduce the amount of coke that is expensive to manufacture, the aging of coke ovens As a countermeasure, in order to reduce the operating rate of the coke oven, the method of injecting auxiliary fuel into the blast furnace that injects auxiliary fuel from the blast furnace tuyere as a fuel to replace coke has been widely implemented for reasons such as .
【０００３】補助燃料としては、当初、燃焼性に優れる
重油等の液体燃料が用いられたが、先のオイルショック
以降、重油価格が高騰し、近年では、石炭を粉砕した微
粉炭をコークスの一部代替燃料として羽口から吹込む所
謂微粉炭吹込み操業（以下ＰＣＩ操業と言う）が一般的
となりつつある。また更に、最近になって、環境問題へ
の対応の一環として、廃プラスチックに代表される廃棄
合成樹脂材並びに廃棄物由来の固形燃料を羽口を介して
高炉内に供給し、熱源及び還元剤として供することが提
案されてもいる。As an auxiliary fuel, a liquid fuel such as heavy oil having excellent flammability was initially used. However, since the oil shock, the price of heavy oil has soared. In recent years, pulverized coal obtained by pulverizing coal has been used as coke. The so-called pulverized coal injection operation (hereinafter, referred to as PCI operation), which is blown from tuyeres, is becoming common as a part alternative fuel. Furthermore, recently, as a part of addressing environmental issues, waste synthetic resin material represented by waste plastic and solid fuel derived from waste have been supplied into the blast furnace through tuyeres, and a heat source and a reducing agent have been supplied. It has also been proposed to serve as
【０００４】ところで、溶銑コストの低減を進めるため
には、微粉炭、重油等の補助燃料の吹込み比を増量しコ
ークスを減量することが最も効果的な方法であるが、従
来よりブローパイプに接続して普通に用いられてきた羽
口〔例えば第３版鉄鋼便覧第II巻製銑・製鋼（第 306頁
図 5・170)、特開昭64−4410号公報、特開平 3−240908
号公報参照〕（以下通常羽口と称す）では、羽口からの
補助燃料吹込み比を増大した場合には、補助燃料が羽口
内で燃焼ガス化するためにガス体積が増し羽口圧損が上
昇すること、更には羽口先のレースウエイ内での燃焼性
が悪化するためコークスとの置換率が悪化すること、等
が確認され、これらが補助燃料吹込み比増量を律速する
と言われている。In order to reduce the cost of hot metal, the most effective method is to increase the injection ratio of auxiliary fuel such as pulverized coal and heavy oil to reduce coke. The tuyere that has been commonly used by connecting it (for example, Iron and Steelmaking, Vol. II, 3rd Edition Iron and Steel Handbook (Page 306, FIG. 5, 170), JP-A-64-4410, JP-A-3-240908)
(Refer to the following publication) (hereinafter referred to as the tuyere), when the auxiliary fuel injection ratio from the tuyere is increased, the auxiliary fuel is gasified in the tuyere, so that the gas volume increases and the tuyere pressure loss increases. It has been confirmed that the rate of increase in the auxiliary fuel injection ratio is controlled by increasing the auxiliary fuel injection ratio, as well as increasing the rate of replacement with coke due to the deterioration of the combustibility in the raceway at the tuyere tip. .
【０００５】そこで、上記問題を改善するために、上記
通常羽口を用い補助燃料として微粉炭を吹込む場合にお
いて、例えば、微粉炭の吹込みランスの先端位置を最適
位置に設定する、あるいは揮発分の高い微粉炭や粒度構
成を細粒よりに移行した微粉炭を用いる、等々の改善が
図られてきたが、これらの改善がなされても上記通常羽
口より安定して吹き込める微粉炭の量は微粉炭吹込み比
で 150kg／銑鉄ｔ程度である。[0005] In order to solve the above problem, when pulverized coal is blown as auxiliary fuel using the normal tuyere, for example, the tip position of the pulverized coal blowing lance is set to an optimum position or volatilized. The use of pulverized coal with a higher particle size and pulverized coal whose particle size structure has been shifted to finer granules has been attempted, but even if these improvements are made, pulverized coal that can be stably blown in from the above normal tuyere The amount is about 150 kg / t of pig iron in pulverized coal injection ratio.
【０００６】一方、特公昭53− 19442号公報、特公平 1
− 28804号公報、特開平 2−104604号公報には溶鉱炉
（高炉）の羽口として用いられるラバール(Laval) 型式
の羽口（以下ラバール羽口と称す）の提案がされてい
る。On the other hand, Japanese Patent Publication No. 53-19442,
Japanese Patent Application Laid-Open No. 28804 and Japanese Patent Application Laid-Open No. 2-104604 propose a Laval-type tuyere (hereinafter referred to as Laval tuyere) used as a tuyere of a blast furnace (blast furnace).
【０００７】例えば、特公昭53− 19442号公報（特に第
１頁第２コラム第８行〜第２頁第３コラム第１行）に
は、溶鉱炉などシャフト炉において使用されるコークス
等の固体燃料の価格が高いことから、その１部を液体状
の炭化水素補助燃料に代え、その補助燃料をシャフト炉
に開口する送風管内に噴射して行う技術に用いる羽口と
してラバール羽口が提案されている。このラバール羽口
は、音速炉口を構成する先細部と末広部及び羽口内で燃
料を噴射する噴射管を有する取換え可能な第１部材と、
この第１部材に連なり第１部材の末広部に延長して末広
部を構成する固定の第２部材とで基本的に構成されてい
る。そして、このラバール羽口では、羽口の末広部にお
いて超音速流の状態から亜音速の状態に推移する条件す
なわち、末広部において衝撃波が形成されるような条件
をつくり、その衝撃波の上流に燃料を噴射することで、
噴射された燃料が衝撃波帯域を通過するときに、燃焼媒
体中への分散作用が効果的になり、煤を生成することな
く燃料の噴射率を高くすることができる。と説明されて
いる。なお、このラバール羽口においては、末広部内に
衝撃波を生じさせるためには、そのシャフト炉の燃焼媒
体の供給速度に応じた、炉口（縮流部）の設計が必要で
あることから、この点に着目し、燃焼媒体供給速度によ
り、炉口の形状を変化できるように、第１部材を取換え
可能としている。For example, Japanese Patent Publication No. 53-19442 (especially page 1, column 2, line 8 to page 2, column 3, line 1) discloses solid fuel such as coke used in shaft furnaces such as blast furnaces. Due to its high price, Laval tuyere has been proposed as a tuyere used for a technique in which a part of the auxiliary fuel is replaced with a liquid hydrocarbon auxiliary fuel and the auxiliary fuel is injected into a blower pipe opened in a shaft furnace. I have. The Laval tuyere is a replaceable first member having a tapered portion constituting a sonic furnace port, a divergent portion, and an injection pipe for injecting fuel in the tuyere,
It is basically composed of a fixed second member connected to the first member and extending to the divergent portion of the first member to form the divergent portion. In this Laval tuyere, a condition for transition from a supersonic flow state to a subsonic state in the flared portion of the tuyere, that is, a condition in which a shock wave is formed in the flared portion, is created, and fuel is provided upstream of the shock wave. By injecting
When the injected fuel passes through the shock wave band, the dispersing action into the combustion medium becomes effective, and the fuel injection rate can be increased without generating soot. It is explained. In order to generate a shock wave in the divergent portion of the Laval tuyere, it is necessary to design a furnace port (contraction section) in accordance with the supply speed of the combustion medium of the shaft furnace. Focusing on the point, the first member can be replaced so that the shape of the furnace port can be changed according to the combustion medium supply speed.
【０００８】また、特公平 1− 28804号公報には、高炉
に用いられる送風羽口自体を、中央部が入口径及び出口
径より小径に形成された所謂ラバール羽口とすることが
提案されている。そして同公報には「このラバール羽口
においては、羽口の入側で亜音速の風は中央部（喉部）
ではマッハ数Ｍ＝１となり、羽口の出口側では超音速の
流れとなるもので、この出口側の風速を超音速とするに
は羽口の入口と出口の風の圧力によって決定される。そ
して、このラバール羽口よりの超音速流は乱流圧縮性自
由噴流となり、ラバール羽口の出口の速度が保持されて
高炉の奥深くまでそのエネルギーが伝えられるものであ
り、その速度コアはマッハ数が大きい程長いのであ
る。」と大要説明され、そして更に、このラバール羽口
によれば、次の如き効果があると説明されている。：
デッドマンと称される不活性な炉芯が狭小化し、稼働内
容積の増大による送風量を増加することができ出銑量が
増加する。：高炉下部の反応性が増大し、直接還元率
の上昇による燃料比を低減できる。：高炉の中心操業
化ができ、炉体熱損失減少による燃料比低減と炉床銑滓
流の中心流化により炉体保護及び炉底保護ができる。
：羽口前運動エネルギーの増大及びレースウエイの深
化により羽口破損回数が減少する。：劣性コークス使
用下ではレースウエイが浅くなるといわれているが、レ
ースウエイ維持が可能となる。Further, Japanese Patent Publication No. 28804/1989 proposes that the blowing tuyere used for the blast furnace is a so-called Laval tuyere whose central portion is formed smaller in diameter than the inlet diameter and the outlet diameter. I have. According to the official gazette, "In this Laval tuyere, the subsonic wind flows in the center (throat) at the entrance of the tuyere.
In this case, the Mach number M = 1, and a supersonic flow occurs on the exit side of the tuyere. The supersonic velocity at the exit side is determined by the wind pressure at the entrance and exit of the tuyere. Then, the supersonic flow from the Laval tuyere becomes a turbulent compressible free jet, the energy of which is transmitted deep into the blast furnace while maintaining the velocity of the outlet of the Laval tuyere. The longer is the longer. It is further described that the Laval tuyere has the following effects. :
An inactive furnace core called a deadman is narrowed, and the amount of blown air can be increased due to an increase in the operating internal volume, thereby increasing the amount of tapping. : The reactivity of the lower part of the blast furnace increases, and the fuel ratio due to the increase in the direct reduction rate can be reduced. : The central operation of the blast furnace can be achieved, the fuel ratio can be reduced by reducing the heat loss of the furnace body, and the furnace body and bottom can be protected by centralizing the hearth iron slag flow.
: The number of tuyere breakage decreases due to an increase in kinetic energy in front of the tuyere and deepening of the raceway. : It is said that the raceway becomes shallow when recessive coke is used, but the raceway can be maintained.
【０００９】また、特開平 2−104604号公報には、微粉
炭を多量に吹き込む高炉の羽口構造に係わり、スロート
部（喉部）を境として前部管と後部管とし、その前部管
の長さを羽口長さの0.2 乃至0.6 とする所謂ラバール羽
口が提案されている。そして同公報には「微粉炭が混合
された熱風は後部管から前部管に入るがスロート部を通
るとき流速を105m／s 以上とされ、前部管の先端から高
炉内に吹き込まれる。」、また「スロート部でのガス流
速は逆火限界速度である105m／s 以上としてあるので、
微粉炭の燃焼は後部管より内部で生じことはない。」、
更に「このラバール羽口によれば、前部管の長さを羽口
長さの0.2 乃至0.6 としているので、羽口先の流速を高
めて逆火現象が防止され、また前部管の摩耗を減少する
ことができる。」と説明されている。Japanese Patent Application Laid-Open No. 2-104604 relates to a tuyere structure of a blast furnace in which a large amount of pulverized coal is blown, wherein a front pipe and a rear pipe are formed with a throat (throat) as a boundary. The so-called Laval tuyere is proposed in which the length of the tuyere is 0.2 to 0.6 of the tuyere length. The publication also states, "Hot air mixed with pulverized coal enters the front pipe from the rear pipe, but has a flow velocity of 105 m / s or more when passing through the throat, and is blown into the blast furnace from the tip of the front pipe.""The gas flow velocity at the throat is set to 105 m / s or more, which is the flashback limit velocity.
Pulverized coal combustion does not occur inside the rear pipe. "
Further, according to this Laval tuyere, since the length of the front tube is set to 0.2 to 0.6 of the tuyere length, the flow velocity at the tuyere tip is increased to prevent a flashback phenomenon and to reduce the wear of the front tube. Can be reduced. "
【００１０】ところで、上述したラバール羽口の場合、
例えば、特公昭53− 19442号公報に説明されたラバール
羽口では、燃焼媒体（熱風）を末広部内において衝撃波
を生じる条件で供給するとともに、その衝撃波の上流に
燃料（補助燃料）を噴射するので、噴射された補助燃料
が衝撃波帯域を通過するときに熱風中へ分散供給される
ことが期待でき、更に煤を生成することなく燃料の噴射
率を高めることが期待できる反面、次のような問題が懸
念される。すなわち、：第１、第２部材の２つの部材
を必要とするため、従来の通常羽口に比して羽口破損等
のトラブル時には、取り換え・復旧作業が煩雑化し、長
時間を要する可能性から炉冷え等の危険性が増す。：
補助燃料吹込み時に、末広部内で衝撃波を形成するため
に、その時々で衝風条件（生産条件）に適した先細部と
末広部、音速炉口径を有する第１部材に設置し直す必要
がある。：また、近年の主流である炉頂圧力を高く保
つ高圧高炉操業では、第１部材入口での圧力を、末広部
で衝撃波を形成させるに必要な圧力にまで、燃焼媒体を
昇圧させる必要があるため、ブロワー、配管等の設備負
荷が増大する。：補助燃料の噴射孔がラバール羽口の
内周面に形成されているため、補助燃料が必ずしも熱風
中へ分散供給されるとは限らない。：第１部材は、音
速炉口を構成する先細部と末広部及び羽口内で燃料を噴
射する噴射管を有し取換え可能に構成されているため、
形状が複雑である上に末広部において衝撃波を生じる形
状に構成されなければならず、実用性が懸念される。By the way, in the case of the above-mentioned Laval tuyere,
For example, in the Laval tuyere described in Japanese Patent Publication No. 53-19442, a combustion medium (hot air) is supplied under conditions that generate a shock wave in the divergent portion, and fuel (auxiliary fuel) is injected upstream of the shock wave. Although it can be expected that the injected auxiliary fuel is dispersed and supplied into the hot air when passing through the shock wave band, and it can be expected that the fuel injection rate can be increased without generating soot, the following problems occur. Is concerned. That is, since two members, the first and second members, are required, replacement / recovery work becomes complicated in the case of trouble such as tuyere breakage as compared with the conventional normal tuyere, and it may take a long time. Danger such as furnace cooling increases. :
At the time of auxiliary fuel injection, in order to form a shock wave in the divergent part, it is necessary to re-install the tapered part suitable for the blast condition (production condition), the divergent part, and the first member having the sonic furnace diameter at each time. . : In recent years, in the high pressure blast furnace operation for maintaining the furnace top pressure high, it is necessary to increase the pressure of the combustion medium to the pressure at the inlet of the first member to the pressure required to form a shock wave in the divergent portion. As a result, the load on equipment such as blowers and pipes increases. : Since the auxiliary fuel injection holes are formed in the inner peripheral surface of the Laval tuyere, the auxiliary fuel is not always dispersed and supplied into the hot air. : Since the first member has a tapered part constituting the sonic furnace port, an injection pipe for injecting fuel in the divergent part and the tuyere, and is configured to be replaceable,
In addition to being complicated in shape, it must be configured to generate a shock wave in the divergent portion, and there is a concern about practicality.
【００１１】また、特公平 1− 28804号公報に説明され
たラバール羽口では、ラバール羽口からの超音速流は乱
流圧縮性自由噴流となり、ラバール羽口の出口の速度が
保持されて高炉の奥深くまでそのエネルギーが伝えられ
るものの、このラバール羽口を用いて補助燃料を併せて
吹込むことについては記載がされていない。Further, in the Laval tuyere described in Japanese Patent Publication No. 1-2804, the supersonic flow from the Laval tuyere becomes a turbulent compressible free jet, and the speed of the outlet of the Laval tuyere is maintained, and the blast furnace is maintained. Although the energy is transmitted to the interior of the car, there is no mention of using the Laval tuyere to inject auxiliary fuel.
【００１２】また、特開平 2−104604号公報に説明され
た微粉炭吹込みラバール羽口では、羽口先の流速を高め
て逆火現象を防止し得ることで多量の微粉炭の吹込みが
期待できるものの、その微粉炭の供給は、同公報の第２
頁下段左第９〜13行に「微粉炭が混合された熱風は後部
管から前部管に入るが、スロート部を通るガスは流速を
105m／s 以上とされ、前部管の先端から高炉内に吹き込
まれる。」と大要説明されているように、微粉炭はラバ
ール羽口の上流側で熱風に混合されてラバール羽口より
供給されるため、逆火現象は防止できても、前部管内及
び前部管を出たところで激しく燃焼が起こり背圧が高く
なるため、良好な衝風条件（生産条件）が期待できな
い。Also, in the pulverized coal injection Laval tuyere described in Japanese Patent Application Laid-Open No. 2-104604, a large amount of pulverized coal is expected to be injected because the flow velocity at the tuyere tip can be increased to prevent the flashback phenomenon. Although it is possible, the supply of pulverized coal is
In the lower left of the page, lines 9-13, "The hot air mixed with pulverized coal enters the front pipe from the rear pipe, but the gas passing through the throat
It is set to 105 m / s or more, and is blown into the blast furnace from the tip of the front pipe. The pulverized coal is mixed with hot air upstream of the Laval tuyere and supplied from the Laval tuyere, so that even if the flashback phenomenon can be prevented, Good combustion conditions (production conditions) cannot be expected because of the intense combustion at the exit of the pipe and the increase in back pressure.
【００１３】[0013]
【発明が解決しようとする課題】そこで、本発明は、上
述したように通常羽口を用いたのでは、例えば補助燃料
として安価な微粉炭を用いた場合に安定して吹き込める
微粉炭量が微粉炭吹込み比でせいぜい 150kg／銑鉄ｔ程
度であって、これ以上の微粉炭吹込み量の増大が難しく
高価なコークスの使用量の低減（コークス比の低減）が
期待できにくいこと、及び本出願人も特公平 1− 28804
号公報に提案しているように、ラバール羽口を用いると
衝風条件（生産条件）によっては高炉内深く熱風が供給
できること、に着目してなしたものであって、その目的
は、高炉への補助燃料吹込みを、例えば微粉炭の場合で
微粉炭吹込み比 150kg／銑鉄ｔ以上を安定して吹込むと
ともに、高価なコークスの使用を極力抑制した高炉への
補助燃料吹込み操業方法を提供するものである。Therefore, according to the present invention, when the normal tuyere is used as described above, the amount of pulverized coal which can be stably blown in, for example, when inexpensive pulverized coal is used as an auxiliary fuel, is reduced. At a pulverized coal injection ratio of at most 150 kg / pig iron t, it is difficult to further increase the pulverized coal injection amount, and it is difficult to reduce the amount of expensive coke used (reduction of coke ratio). Applicant is also Tokuhei 1-28044
As proposed in the publication, the use of a Laval tuyere focuses on the fact that hot air can be supplied deep inside the blast furnace depending on the blast conditions (production conditions). In the case of pulverized coal, for example, in the case of pulverized coal, a pulverized coal injection ratio of 150 kg / pig iron t or more is stably injected, and an auxiliary fuel injection operation method for a blast furnace that minimizes the use of expensive coke is proposed. To provide.
【００１４】[0014]
【課題を解決するための手段】本発明者等は、上記の課
題を解決するために、鋭意調査、検討を重ね、従来技術
の項で説明したような現状を把握し、更に本出願人が先
に特公平 1− 28804号公報に提案したラバール羽口に着
目するとともに、通常羽口に用いられている補助燃料吹
込みランスに着目して本発明をなしたものである。そし
て、その要旨（請求項１）は、羽口に接続されたブロー
パイプの接続部近傍から羽口先端に至る間の管内にブロ
ーパイプの内径及び羽口先端の内径より小径の縮径部を
有し、且つ、補助燃料吹込みランスの先端位置が前記縮
径部より羽口先端側に配設されてなる構成の補助燃料吹
込み羽口より補助燃料を吹込む高炉への補助燃料吹込み
方法であって、前記補助燃料吹込みランスより補助燃料
を吹込むとともに、酸素を吹込む、高炉への補助燃料吹
込み方法とするものである。Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have conducted intensive investigations and examinations, grasped the present situation as described in the section of the prior art, and The present invention focuses on the Laval tuyere proposed in Japanese Patent Publication No. 1-28041 and also focuses on the auxiliary fuel injection lance normally used for the tuyere. The gist (Claim 1) is that a reduced diameter portion smaller in diameter than the inner diameter of the blow pipe and the inner diameter of the tuyere tip is provided in the pipe from the vicinity of the connection portion of the blow pipe connected to the tuyere to the tuyere tip. Auxiliary fuel injection into a blast furnace that blows auxiliary fuel from an auxiliary fuel injection tuyere having a configuration in which a tip position of an auxiliary fuel injection lance is disposed closer to a tuyere end than the reduced diameter portion. A method for injecting auxiliary fuel into the blast furnace by injecting oxygen while injecting auxiliary fuel from the auxiliary fuel injection lance.
【００１５】上記構成では、先願のラバール羽口の構造
を利用するものであるが、羽口の内径が大径であった
り、あるいは羽口の全長が比較的短い場合なども考慮し
て、羽口に接続されたブローパイプの接続部近傍を含め
てラバール羽口に構成してもよいとしたもので、羽口自
体でラバール羽口が構成できる場合には羽口自体でラバ
ール羽口を構成してもよい。このラバール羽口では縮径
部を出た流れは高速の中心流と縮径部の下流側の末広部
に沿った拡がりのある流れとができ、これによって高炉
内に深度の大きい且つ拡がりのあるレースウエイが形成
できる。そして、上記構成では、このラバール羽口に対
して補助燃料吹込みランスの先端位置を、縮径部より羽
口先端側に配設するものである。すなわち、補助燃料吹
込みランスの先端位置がラバール羽口の縮径部より後方
（送風方向の上流側）に配設した場合には、補助燃料が
縮径部の上流側で混合されてしまい、その結果、縮径部
より下流側の末広部内で、あるいはその末広部を出た近
傍で激しく燃焼し背圧（羽口内圧損）が高くなり、良好
な衝風条件（生産条件）が期待できなくなる。これに対
して、補助燃料吹込みランスの先端位置を、ラバール羽
口の縮径部より羽口先端側に配設した場合には、縮径部
を経た熱風が補助燃料吹込みランスの先端部によって攪
拌されるので、吹込まれた補助燃料が熱風中に攪拌分散
されながら高速で高炉内に吹込め、これにより、縮径部
より下流側の末広部内で、あるいはその末広部を出た近
傍で激しく燃焼することがなく羽口内圧損を低くして高
炉内深く補助燃料を吹き込んで燃焼させることができ
る。In the above-mentioned configuration, the structure of the Laval tuyere of the prior application is used. However, in consideration of the case where the inner diameter of the tuyere is large or the total length of the tuyere is relatively short, It is said that the Laval tuyere may be configured including the vicinity of the connection part of the blow pipe connected to the tuyere. You may comprise. In this Laval tuyere, the flow exiting the reduced diameter portion has a high-speed central flow and a widening flow along the divergent portion on the downstream side of the reduced diameter portion, and as a result, the flow has a large depth and spreads in the blast furnace. A raceway can be formed. And in the said structure, the front-end | tip position of an auxiliary fuel injection lance with respect to this Laval tuyere is arrange | positioned at the tuyere-tip front side from a diameter reduction part. In other words, if the tip position of the auxiliary fuel injection lance is located behind the reduced diameter portion of the Laval tuyere (upstream in the blowing direction), the auxiliary fuel is mixed upstream of the reduced diameter portion, As a result, the fuel burns violently in or near the divergent portion downstream of the reduced diameter portion, and the back pressure (internal pressure loss in the tuyere) increases, so that favorable blast conditions (production conditions) cannot be expected. . On the other hand, when the tip position of the auxiliary fuel injection lance is located closer to the tuyere tip than the reduced diameter portion of the Laval tuyere, the hot air that has passed through the reduced diameter portion causes the distal end of the auxiliary fuel injection lance to pass through. The injected auxiliary fuel is injected into the blast furnace at a high speed while being agitated and dispersed in the hot air, whereby the auxiliary fuel is injected into the divergent portion downstream of the reduced diameter portion or in the vicinity of the divergent portion. The tuyere can be burned deeply in the blast furnace by lowering the pressure loss in the tuyere without violent combustion.
【００１６】しかし、上記の如く補助燃料吹込みランス
によって吹込まれた補助燃料は縮径部より下流側の末広
部内で、あるいはその末広部を出た近傍で激しく燃焼す
るが、補助燃料が特に微粉炭や廃棄プラスチック粉のよ
うな固体の場合の吹込みにおいては、重油のような液
体、天然ガスのような気体の吹込みと比較して末広部内
で、あるいはレースウエイ内での燃焼率が低いため、未
燃物がレースウエイから排出されることが懸念される。
もし、未燃物がレースウエイから排出された場合には、
その未燃物が高炉の軟化融着帯で軟化した鉄鉱石に吸着
され、直接還元反応でガス化（例えばFeO ＋C ＝Fe＋C
O）することになるが、ガス化が不十分で、この未燃物
が高炉内をガスと共に上昇するとき、この未燃物が通気
抵抗になり炉内圧損を高めることになる。あるいはその
まま炉外に排出され有効に利用されない。そこで本発明
では、更に補助燃料吹込みランスより補助燃料を吹込む
とともに、酸素を吹込むことにしたものである。すなわ
ち、通常羽口で酸素を吹込んだ場合には、羽口内での燃
焼は羽口内圧損を高めるが、ラバール羽口では吹込み位
置が末広に形成されているので羽口内圧損の増大はほと
んどなく、むしろ燃焼圧がレースウエイに向かうため幅
のある深度のあるレースウエイが形成でき、しかも補助
燃料が微粉炭や廃棄プラスチック粉のような固体の場合
であっても未燃物の発生が抑制できるので通気性（炉内
圧損）が損なわれることがなく、あるいは炉外に排出さ
れる未燃物が皆無となり炉内で還元に有効に利用される
ので、これにより、高炉への補助燃料吹込みが、例えば
微粉炭の場合で微粉炭吹込み比 150kg／銑鉄ｔ以上、更
には微粉炭吹込み比 200kg／銑鉄ｔ乃至 300kg／銑鉄ｔ
以上を安定して吹込むことができるようになり、従って
高価なコークスの使用を低減できコークス比を下げるこ
とができる。However, as described above, the auxiliary fuel injected by the auxiliary fuel injection lance burns violently in the divergent portion downstream of the reduced diameter portion or in the vicinity of the divergent portion. In the case of injection of solids such as charcoal and waste plastic powder, the combustion rate in the Suehiro area or the raceway is lower than in the injection of liquids such as heavy oil or gas such as natural gas. Therefore, there is a concern that unburned matter is discharged from the raceway.
If unburned material is discharged from the raceway,
The unburned matter is adsorbed on the iron ore softened in the softening cohesive zone of the blast furnace and gasified by direct reduction reaction (for example, FeO + C = Fe + C
O), but when the gasification is insufficient and the unburned matter rises together with the gas in the blast furnace, the unburned matter becomes a ventilation resistance and increases the pressure loss in the furnace. Or, it is discharged as it is from the furnace and is not used effectively. Therefore, in the present invention, oxygen is also blown while blowing auxiliary fuel from the auxiliary fuel blowing lance. That is, when oxygen is normally blown into the tuyere, combustion in the tuyere increases the pressure loss in the tuyere, but in the Laval tuyere, the blowing position is formed divergent, so the increase in the pressure loss in the tuyere is almost Rather, the combustion pressure is directed toward the raceway, so a wide and deep raceway can be formed, and even if the auxiliary fuel is a solid such as pulverized coal or waste plastic powder, generation of unburned substances is suppressed. As a result, the air permeability (furnace pressure loss) is not impaired, or there is no unburned matter discharged outside the furnace, and it is effectively used for reduction in the furnace. For example, in the case of pulverized coal, the pulverized coal injection ratio is 150 kg / pig iron t or more, and the pulverized coal injection ratio is 200 kg / pig iron t to 300 kg / pig iron t.
The above can be stably blown, so that the use of expensive coke can be reduced and the coke ratio can be reduced.
【００１７】また、上記のように、補助燃料吹込みラン
スの先端位置をラバール羽口の縮径部より羽口先端側に
配設することで、縮径部を経た熱風が補助燃料吹込みラ
ンスの先端部によって攪拌され、その結果、吹込まれた
補助燃料がラバール羽口の縮径部より先で熱風中に攪拌
分散されるので、縮径部の先の末広部での熱風速度を、
特公昭53− 19442号公報に説明されているような衝撃波
を発生させるような超音速（Ｍ＞１）にしてまでも攪拌
分散させる必要がなく、亜音速(0.3＜Ｍ＜0.8)程度で、
十分補助燃料を分散させ、しかも幅のある且つ長さのあ
る良好なレースウエイを形成させて補助燃料を高炉内に
吹込むことができる。また、亜音速の場合には、超音速
の場合に比較して送風圧力が低くてよいことから、ブロ
ワーや送風管などの送風設備のコストを低く抑えること
ができる。Further, as described above, the tip of the auxiliary fuel injection lance is disposed closer to the tip of the tuyere than the reduced diameter portion of the Laval tuyere, so that the hot air passing through the reduced diameter portion can be used as the auxiliary fuel injection lance. As a result, the injected auxiliary fuel is stirred and dispersed in the hot air before the reduced diameter portion of the Laval tuyere, so that the hot air velocity at the divergent portion ahead of the reduced diameter portion is
It is not necessary to stir and disperse even at a supersonic speed (M> 1) which generates a shock wave as described in JP-B-53-19442, and at a subsonic speed (0.3 <M <0.8),
The auxiliary fuel can be blown into the blast furnace by sufficiently dispersing the auxiliary fuel and forming a good raceway having a width and a length. Further, in the case of subsonic speed, the blowing pressure may be lower than in the case of supersonic speed, so that the cost of blowing equipment such as a blower and a blowing pipe can be reduced.
【００１８】そして、上記本発明に係る高炉への補助燃
料吹込み方法においては、酸素はブローパイプより上流
側で熱風中に供給してもよいが、補助燃料吹込みランス
として二重管構造のランスを用い、中心部より補助燃料
を、外周部より酸素を吹込んでもよく、このように二重
管構造のランスを用いた方が、予め上流側で熱風中に供
給し均一分散された酸素より補助燃料に対する酸素濃度
を高くできるので、ラバール羽口の縮径部の先の末広部
内での燃焼性を高めることができ、上述したように通常
羽口ではそれほど効果的に吹込めなかった、特に微粉炭
や廃棄プラスチック粉のような固体の補助燃料を多量に
しかもラバール羽口の形状と相まって効果的に高炉へ吹
込むことができる。In the method of injecting auxiliary fuel into the blast furnace according to the present invention, oxygen may be supplied into the hot air upstream of the blow pipe, but the auxiliary fuel injection lance has a double pipe structure. A lance may be used to inject auxiliary fuel from the center and oxygen from the outer periphery. Using a lance having a double-pipe structure in this way makes it possible to supply oxygen into hot air in advance on the upstream side and distribute oxygen uniformly. Since the oxygen concentration with respect to the auxiliary fuel can be increased, the flammability in the divergent portion at the tip of the reduced diameter portion of the Laval tuyere can be increased, and as described above, the normal tuyere could not blow so much, In particular, a large amount of solid auxiliary fuel such as pulverized coal or waste plastic powder can be effectively blown into the blast furnace in combination with the shape of the Laval tuyere.
【００１９】また、上記本発明に係る高炉への補助燃料
吹込み方法においては、酸素を 1〜15％酸素富化となる
ように吹込むとよく、酸素富化が 1％未満では、微粉炭
など固体補助燃料の場合での燃焼促進効果は期待し得な
い。一方、生産性一定のもとでは酸素富化が15％を超え
ると、熱風量の減量により羽口流速が大きく低下し、レ
ースウエイが小さくなり、微粉炭のレースウエイ滞留時
間の低下に伴って燃焼率が下がる。また、炉内のガス分
配の悪化、周辺流化を引き起し、安定な高炉操業を乱す
可能性が高い。このようなことから、酸素を 1〜15％酸
素富化とするもので、この範囲内であれば段落番号〔０
０１６〕に記載した作用効果を十分に享受し得ることが
できる。そして、このような作用効果をより確実に享受
し得るには 2〜10％酸素富化とすることが望ましい。In the method of injecting auxiliary fuel into a blast furnace according to the present invention, oxygen is preferably injected so as to be 1 to 15% oxygen-enriched. For example, the effect of promoting combustion in the case of a solid auxiliary fuel cannot be expected. On the other hand, if the oxygen enrichment exceeds 15% under a constant productivity, the tuyere flow velocity decreases greatly due to the decrease in the amount of hot air, the raceway becomes smaller, and the residence time of pulverized coal in the raceway decreases. Combustion rate decreases. In addition, there is a high possibility that deterioration of gas distribution in the furnace and peripheral flow will be caused, and stable blast furnace operation will be disturbed. For this reason, oxygen is enriched in oxygen by 1 to 15%, and within this range, the paragraph number [0
016] can be sufficiently enjoyed. Then, in order to more surely enjoy such an effect, it is desirable to make the oxygen enriched by 2 to 10%.
【００２０】[0020]
【発明の実施の形態】以下、本発明の実施形態を図面に
基づいて説明する。図１は、本発明の高炉への補助燃料
吹込み方法に適用するラバール羽口の概要を示す断面説
明図であって、この図１において、１はラバール羽口、
２は補助燃料吹込みランス、３はブローパイプである。Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional explanatory view showing an outline of a Laval tuyere applied to the method of injecting auxiliary fuel into a blast furnace according to the present invention. In FIG.
2 is an auxiliary fuel injection lance, and 3 is a blow pipe.
【００２１】ラバール羽口１は、本例では羽口自体にラ
バール型が形成された例で、中央部に縮径部４が形成さ
れ、その縮径部４の上流側（ブローパイプ３側）に先細
りに形成された入口部５、下流側に末広に形成された出
口部６を有し、縮径部４の内径D2、入口部５の内径D1、
出口部６の内径D3とした場合に、D1＞D2＜D3の関係を満
たす形状に形成されている。そして、ラバール羽口１の
入口部５側にはブローパイプ３が接続され、またブロー
パイプ３を貫通させて微粉炭吹込みランス２が対称位置
に２本、且つその先端７の位置を縮径部４より僅かに出
口部６側に出して装着されている。In the present embodiment, the Laval tuyere 1 is an example in which a Laval type is formed in the tuyere itself, and a reduced diameter portion 4 is formed in the center portion, and the upstream side of the reduced diameter portion 4 (blow pipe 3 side). An inlet portion 5 formed to be tapered, an outlet portion 6 formed to be divergent on the downstream side, an inner diameter D2 of the reduced diameter portion 4, an inner diameter D1 of the inlet portion 5,
When the inside diameter D3 of the outlet part 6 is set, it is formed in a shape that satisfies the relationship of D1> D2 <D3. A blow pipe 3 is connected to the inlet portion 5 side of the Laval tuyere 1, and two pulverized coal blowing lances 2 are pierced through the blow pipe 3, and the position of the tip 7 is reduced in diameter. It is mounted slightly out of the part 4 to the outlet part 6 side.
【００２２】図２は、燃焼実験装置の概略図であって、
実際の高炉羽口部に模した構造に設計されている。この
図において微粉炭８は地上ホッパ９からスクリューコン
ベア10によってコールビン11へ搬送される。コールビン
11の下部には粉体燃料定量供給機12が設けられており、
この部分で定量切り出された微粉炭８は、輸送気体13と
共に輸送管14によって微粉炭吹込みバーナ２へ送られ
る。一方高温熱風炉15で得られた熱風は、送風管16から
ブローパイプ３及びラバール羽口１を経て燃焼試験炉17
へ送られる。符号18は煙突である。FIG. 2 is a schematic diagram of a combustion test apparatus,
It is designed to mimic the actual tuyeres. In this figure, pulverized coal 8 is conveyed from a ground hopper 9 to a coal bin 11 by a screw conveyor 10. Cole bin
The lower part of 11 is provided with a powder fuel metering device 12,
The pulverized coal 8 quantitatively cut out in this portion is sent to the pulverized coal injection burner 2 by the transport pipe 14 together with the transport gas 13. On the other hand, the hot air obtained in the high-temperature hot-blast furnace 15 passes through the blow pipe 3 through the blow pipe 3 and the Laval tuyere 1, and the combustion test furnace 17
Sent to Reference numeral 18 denotes a chimney.
【００２３】高炉の燃料吹込み部は一般の燃焼装置とは
全く異なり、ブローパイプ３及び通常羽口（この実験で
は本発明に係るラバール羽口１）で構成されているの
で、上記燃焼実験装置は実際の高炉吹込み部に近似させ
ている。また燃焼試験炉17には粉体燃料の燃焼状態及び
着火状態を観察するための覗き窓を多数設けるととも
に、炉内温度、炉内ガス組成、炉内ダスト、火炎輻射量
等を測定するための検査孔が設けられ、且つブローパイ
プ３の上流側曲がり部には該ブローパイプ３の壁面への
灰の付着状況を観察するための覗き窓19が設けられてい
る。The fuel injection section of the blast furnace is completely different from a general combustion apparatus, and is constituted by a blow pipe 3 and a normal tuyere (in this experiment, the Laval tuyere 1 according to the present invention). Is approximated to the actual blast furnace injection section. In addition, the combustion test furnace 17 is provided with a large number of viewing windows for observing the combustion state and the ignition state of the powder fuel, and is used for measuring the furnace temperature, the furnace gas composition, the furnace dust, the flame radiation amount, and the like. An inspection hole is provided, and a viewing window 19 for observing the state of adhesion of ash to the wall surface of the blow pipe 3 is provided at the upstream bent portion of the blow pipe 3.
【００２４】以下は図２に示す燃焼実験装置を用い、下
記の条件で微粉炭の吹込みを行い、それぞれの条件での
羽口内圧力損失、送風圧力変動及び未燃物の有無を調査
した。その結果を表１に示す。なお、条件、条件、
条件、条件で酸素富化量3％とした外は、送風条件
等は同じにして調査した。 条件：燃焼実験装置の羽口部に通常羽口を設け、ブロ
ーパイプ３の微粉炭吹込みバーナ２より微粉炭を吹込ん
だ（比較例１）。 条件：燃焼実験装置の羽口部に通常羽口を設け、更に
ブローパイプ３の微粉炭吹込みバーナ２より上流側に酸
素吹込みバーナ20を設け、微粉炭と酸素を同時に吹込ん
だ（比較例２）。 条件：燃焼実験装置の羽口部に通常羽口を設け、更に
ブローパイプ３の微粉炭吹込みバーナ２として図３に示
す二重管構造のランス21を用い、この二重管構造のラン
ス21より中心管22より微粉炭を、外周管23より酸素を同
時に吹込んだ（比較例３）。 条件：燃焼実験装置の羽口部にラバール羽口１を設
け、ブローパイプ３の微粉炭吹込みバーナ２より微粉炭
を吹込んだ。このとき微粉炭吹込みバーナ２の先端７の
位置を縮径部４より僅かに出口部６側に出して装着した
（比較例４）。 条件：燃焼実験装置の羽口部にラバール羽口１を設
け、更にブローパイプ３の微粉炭吹込みバーナ２より上
流側に酸素吹込みバーナ20を設け、微粉炭と酸素を同時
に吹込んだ（発明例１）。 条件：燃焼実験装置の羽口部にラバール羽口１を設
け、更にブローパイプ３の微粉炭吹込みバーナ２として
図３に示す二重管構造のランス21を用い、この二重管構
造のランス21より中心管22より微粉炭を、外周管23より
酸素を同時に吹込んだ（発明例２）。In the following, pulverized coal was blown under the following conditions using the combustion test apparatus shown in FIG. 2, and the tuyere pressure loss, blast pressure fluctuation, and the presence or absence of unburned materials were investigated under each condition. Table 1 shows the results. In addition, conditions, conditions,
Except that the oxygen enrichment amount was 3% in the conditions and conditions, the blowing conditions and the like were the same and the investigation was performed. Conditions: Normal tuyeres were provided at the tuyere of the combustion experimental apparatus, and pulverized coal was blown from the pulverized coal blowing burner 2 of the blow pipe 3 (Comparative Example 1). Conditions: A normal tuyere was provided at the tuyere of the combustion test apparatus, and an oxygen blowing burner 20 was further provided upstream of the pulverized coal blowing burner 2 of the blow pipe 3 to simultaneously blow pulverized coal and oxygen. Example 2). Conditions: A normal tuyere is provided at the tuyere of the combustion experimental apparatus, and a lance 21 having a double pipe structure shown in FIG. 3 is used as the pulverized coal injection burner 2 of the blow pipe 3. Pulverized coal was blown from the center pipe 22 and oxygen was blown from the outer pipe 23 at the same time (Comparative Example 3). Conditions: The Laval tuyere 1 was provided at the tuyere part of the combustion test apparatus, and pulverized coal was blown from the pulverized coal injection burner 2 of the blow pipe 3. At this time, the position of the tip 7 of the pulverized coal blowing burner 2 was mounted slightly outside the reduced diameter portion 4 toward the outlet portion 6 (Comparative Example 4). Conditions: A Laval tuyere 1 is provided at the tuyere of the combustion experimental apparatus, and an oxygen blowing burner 20 is further provided upstream of the pulverized coal blowing burner 2 of the blow pipe 3, and pulverized coal and oxygen are simultaneously blown ( Invention Example 1). Conditions: A Laval tuyere 1 is provided at the tuyere of the combustion test apparatus, and a lance 21 having a double pipe structure shown in FIG. Pulverized coal was simultaneously blown from the center pipe 22 through 21 and oxygen was blown from the outer pipe 23 simultaneously (Invention Example 2).
【００２５】なお、図３は、補助燃料（微粉炭等）と酸
素を同時に吹込むことのできる二重管構造ランス21を説
明図であって、この二重管構造ランス21は基本的に、中
心管22とその外周に後端を溶接固定された外周管23とで
構成され、中心管22はその先端部に外周面に複数（図示
では８本）のスパイラル溝24が形成され、更に後端部に
開閉バルブ25及び接続管26が設けられている。また外周
管23はその後端側の側面に支管27が接続され、その支管
27の後端部に開閉バルブ28及び接続管29が設けられてい
る。そして、接続管26に補助燃料供給管を、接続管29に
酸素供給管をそれぞれ接続することで、補助燃料（微粉
炭等）と酸素を同時に吹込むことができる。FIG. 3 is an explanatory view of a double-pipe-structure lance 21 capable of simultaneously injecting auxiliary fuel (pulverized coal or the like) and oxygen. The center tube 22 includes an outer tube 23 having a rear end welded and fixed to the outer periphery of the center tube 22. The center tube 22 has a plurality of (eight in the illustrated) spiral grooves 24 formed on an outer peripheral surface at a front end thereof. An open / close valve 25 and a connection pipe 26 are provided at the ends. Further, the outer pipe 23 has a branch pipe 27 connected to the side surface on the rear end side thereof,
An opening / closing valve 28 and a connection pipe 29 are provided at a rear end of the 27. By connecting an auxiliary fuel supply pipe to the connection pipe 26 and an oxygen supply pipe to the connection pipe 29, auxiliary fuel (pulverized coal or the like) and oxygen can be simultaneously blown.
【００２６】[0026]
【表１】 [Table 1]
【００２７】表１から明らかなように、比較例２及び比
較例３は通常羽口を用いて酸素を富化したもので、通常
羽口内での燃焼性が高くなった分、酸素富化をしなかっ
た比較例１よりも羽口内圧力損失が増し、また送風圧力
変動が大きくなった。一方、未燃物は比較例１では認め
られたものの、比較例２と３では認められなかった。こ
れに対して、本発明例１は通常羽口に換えてラバール羽
口１を用いたもので、未燃物は比較例１と同様に認めら
れたものの、羽口内圧力損失は比較例１よりも0.05kg／
cm2 程度減少し、また送風圧力変動は2g／cm2 程度小さ
くなった。また本発明例２と３においては羽口内圧力損
失及び送風圧力変動は本発明例１とほぼ同じであった
が、未燃物は全く認められず酸素の富化によって燃焼性
が高まったことが認められる。なお、上記調査では本発
明例１で未燃物が認められる微粉炭量を予め確認しその
微粉炭量を以て調査したもので、ラバール羽口１で必ず
未燃物が発生すると言うものではない。As is clear from Table 1, Comparative Examples 2 and 3 are obtained by enriching oxygen using a normal tuyere. The pressure loss in the tuyere was larger than that of Comparative Example 1 in which the air pressure was not increased, and the fluctuation of the blowing pressure was larger. On the other hand, unburned substances were found in Comparative Example 1, but not in Comparative Examples 2 and 3. On the other hand, in Example 1 of the present invention, the Laval tuyere 1 was used in place of the normal tuyere. Although the unburned matter was recognized as in Comparative example 1, the pressure loss in the tuyere was lower than that in Comparative example 1. Also 0.05kg /
cm 2 , and the blowing pressure fluctuation was reduced by about 2 g / cm 2 . In Examples 2 and 3 of the present invention, the pressure loss in the tuyere and the fluctuation of the blowing pressure were almost the same as those of Example 1 of the present invention. However, no unburned matter was observed and the combustibility was increased by enrichment of oxygen. Is recognized. In the above investigation, the amount of pulverized coal in which unburned matter was found in Example 1 of the present invention was previously confirmed, and the amount of pulverized coal was examined using the amount of pulverized coal.
【００２８】[0028]
【発明の効果】以上説明したように、本発明に係る高炉
への補助燃料吹込み方法（請求項１）によれば、ラバー
ル羽口構造を用い補助燃料吹込みランスより補助燃料を
吹込む場合に加え、更に酸素を富化するため、酸素によ
って補助燃料が羽口出側で激しく燃焼するが、羽口内圧
損が高くなることはなく、また特に補助燃料が微粉炭や
廃棄プラスチック粉のような固体の補助燃料であっても
未燃物の発生が大きく抑制されるので、未燃物による通
気抵抗が軽減され炉内圧損が抑制でき、これにより、高
炉への補助燃料吹込みを、従来（通常羽口を用い補助燃
料吹込みランスより補助燃料を吹込む場合）はもとよ
り、ラバール羽口構造を用い補助燃料吹込みランスより
補助燃料を吹込む場合よりも更に安定して大量に、例え
ば微粉炭の場合で微粉炭吹込み比 150kg／銑鉄ｔ以上、
更には微粉炭吹込み比 200kg／銑鉄ｔ乃至 300kg／銑鉄
ｔ以上を安定して吹込むことができるようになり、高価
なコークスの使用が低減できる。As described above, according to the method for injecting auxiliary fuel into a blast furnace according to the present invention (claim 1), when auxiliary fuel is injected from an auxiliary fuel injection lance using a Laval tuyere structure. In addition to the oxygen enrichment, the auxiliary fuel burns violently at the tuyere exit side due to oxygen, but the tuyere internal pressure loss does not increase, and especially the auxiliary fuel such as pulverized coal or waste plastic powder Even if it is a solid auxiliary fuel, the generation of unburned matter is greatly suppressed, so that the ventilation resistance due to the unburned matter is reduced and the pressure loss in the furnace can be suppressed. In addition to the case where auxiliary fuel is injected from the auxiliary fuel injection lance using the normal tuyere), more stable and large amount of fine powder Fine in the case of charcoal Sumi吹 inclusive ratio 150kg / pig iron t or more,
Further, the pulverized coal injection ratio of 200 kg / pig iron t to 300 kg / pig iron t or more can be stably injected, and the use of expensive coke can be reduced.
【００２９】また、本発明に係る高炉への補助燃料吹込
み方法（請求項２）によれば、補助燃料吹込みランスと
して二重管構造のランスを用いて、中心部より補助燃料
を、外周部より酸素を吹込むので、羽口内に吹込まれた
補助燃料に対する酸素濃度を高くできるので、ラバール
羽口の縮径部の先の末広部内での燃焼性を高めることが
でき、より安定して大量に、例えば微粉炭の場合で微粉
炭吹込み比 150kg／銑鉄ｔ以上、更には微粉炭吹込み比
200kg／銑鉄ｔ乃至 300kg／銑鉄ｔ以上を安定して吹込
むことができるようになり、高価なコークスの使用が低
減できる。According to the method for injecting auxiliary fuel into a blast furnace according to the present invention (claim 2), a lance having a double pipe structure is used as an auxiliary fuel injection lance, and auxiliary fuel is supplied from the center to the outer periphery. Since oxygen is blown into the tuyere, the oxygen concentration of the auxiliary fuel blown into the tuyere can be increased, so that the flammability in the divergent portion at the tip of the reduced diameter portion of the Laval tuyere can be increased and more stable In large quantities, for example, in the case of pulverized coal, pulverized coal injection ratio is 150 kg / pig iron or more, and furthermore, pulverized coal injection ratio
200 kg / pig iron t to 300 kg / pig iron t or more can be stably blown, and the use of expensive coke can be reduced.
【００３０】また、補助燃料吹込みランスの先端位置
を、ラバール羽口の縮径部より羽口先端側に配設するこ
とで、縮径部を経た熱風が補助燃料吹込みランスの先端
部によって攪拌されるので、吹込まれた微粉炭が熱風中
に攪拌分散されるため、縮径部の先の末広部での熱風の
速度を亜音速(0.3＜Ｍ＜0.8)程度で十分微粉炭を分散さ
せて操業することができ、ブロワーや送風管などの送風
設備のコストを低く抑えて操業できる。Further, by disposing the tip of the auxiliary fuel injection lance at the tip of the tuyere from the reduced diameter portion of the Laval tuyere, the hot air having passed through the reduced diameter portion is moved by the tip of the auxiliary fuel injection lance. Since the pulverized coal injected is stirred and dispersed in the hot air, the pulverized coal is sufficiently dispersed at the subsonic speed (0.3 <M <0.8) at the divergent portion ahead of the reduced diameter portion. The operation can be performed while the cost of blowing equipment such as a blower and a blower tube is kept low.
【図１】本発明の高炉への補助燃料吹込み方法に適用す
るラバール羽口の概要を示す断面説明図である。FIG. 1 is an explanatory sectional view showing an outline of a Laval tuyere applied to a method of injecting auxiliary fuel into a blast furnace according to the present invention.
【図２】燃焼実験装置の概略図である。FIG. 2 is a schematic diagram of a combustion test apparatus.
【図３】本発明の高炉への補助燃料吹込み方法に適用す
る補助燃料吹込み用二重管構造ランスの説明図であっ
て、ａは断面図、ｂはａのＸ−Ｘ断面図である。FIGS. 3A and 3B are explanatory views of a double-tube structure lance for auxiliary fuel injection applied to the method for injecting auxiliary fuel into a blast furnace according to the present invention, wherein a is a cross-sectional view and b is a XX cross-sectional view of a. is there.
１：ラバール羽口 ２：補助燃料吹込みランス ３：ブローパイプ ４：縮径部
５：入口部 ６：出口部 ７：ランス先端 2
1：二重管構造ランス 22：中心管 23：外周管 2
3：スパイラル溝 25, 28：開閉バルブ 26, 29：接続管 2
7：支管1: Laval tuyere 2: auxiliary fuel injection lance 3: blow pipe 4: reduced diameter portion
5: Inlet 6: Outlet 7: Lance tip 2
1: Double tube lance 22: Center tube 23: Outer tube 2
3: Spiral groove 25, 28: Open / close valve 26, 29: Connection pipe 2
7: Branch pipe
───────────────────────────────────────────────────── フロントページの続き (72)発明者 野沢 健太郎 兵庫県加古川市金沢町１番地 株式会社神 戸製鋼所加古川製鉄所内 Ｆターム(参考） 4K012 BD04 BE01 BE02 4K015 AC02 AD02 AD10 FC03 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Kentaro Nozawa 1 Kanazawa-cho, Kakogawa-shi, Hyogo F-term (reference) in Kobe Steel Works, Kakogawa Works 4K012 BD04 BE01 BE02 4K015 AC02 AD02 AD10 FC03
Claims (3)
近傍から羽口先端に至る間の管内にブローパイプの内径
及び羽口先端の内径より小径の縮径部を有し、且つ、補
助燃料吹込みランスの先端位置が前記縮径部より羽口先
端側に配設されてなる構成の補助燃料吹込み羽口より補
助燃料を吹込む高炉への補助燃料吹込み方法であって、
前記補助燃料吹込みランスより補助燃料を吹込むととも
に、酸素を吹込むことを特徴とする高炉への補助燃料吹
込み方法。A tube having a reduced diameter smaller than the inner diameter of the blowpipe and the inner diameter of the tuyere tip in a pipe extending from the vicinity of the connection part of the blowpipe connected to the tuyere to the tip of the tuyere, and A method of injecting auxiliary fuel into a blast furnace in which auxiliary fuel is injected from an auxiliary fuel injection tuyere having a configuration in which a tip position of a fuel injection lance is disposed closer to a tuyere end than the reduced diameter portion,
A method for injecting auxiliary fuel into a blast furnace, wherein auxiliary fuel is injected from the auxiliary fuel injection lance and oxygen is also injected.
近傍から羽口先端に至る間の管内にブローパイプの内径
及び羽口先端の内径より小径の縮径部を有し、且つ、補
助燃料吹込みランスの先端位置が前記縮径部より羽口先
端側に配設されてなる構成の補助燃料吹込み羽口より補
助燃料を吹込む高炉への補助燃料吹込み方法であって、
前記補助燃料吹込みランスとして二重管構造のランスを
用い、中心部より補助燃料を、外周部より酸素を吹込む
ことを特徴とする高炉への補助燃料吹込み方法。2. A tube having a reduced diameter portion smaller than the inner diameter of the blow pipe and the inner diameter of the tuyere tip in a pipe extending from the vicinity of the connection portion of the blow pipe connected to the tuyere to the tip of the tuyere. A method of injecting auxiliary fuel into a blast furnace in which auxiliary fuel is injected from an auxiliary fuel injection tuyere having a configuration in which a tip position of a fuel injection lance is disposed closer to a tuyere end than the reduced diameter portion,
A method of injecting auxiliary fuel into a blast furnace, characterized in that a lance having a double pipe structure is used as the auxiliary fuel injection lance, and auxiliary fuel is injected from a center portion and oxygen is injected from an outer peripheral portion.
料吹込み方法において、酸素を 1〜15％酸素富化となる
ように吹込む高炉への補助燃料吹込み方法。3. The method for injecting auxiliary fuel into a blast furnace according to claim 1 or 2, wherein oxygen is injected into the blast furnace so as to be oxygen-enriched by 1 to 15%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP37042598A JP3450205B2 (en) | 1998-12-25 | 1998-12-25 | How to inject auxiliary fuel into the blast furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP37042598A JP3450205B2 (en) | 1998-12-25 | 1998-12-25 | How to inject auxiliary fuel into the blast furnace |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000192119A true JP2000192119A (en) | 2000-07-11 |
| JP3450205B2 JP3450205B2 (en) | 2003-09-22 |
Family
ID=18496883
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP37042598A Expired - Lifetime JP3450205B2 (en) | 1998-12-25 | 1998-12-25 | How to inject auxiliary fuel into the blast furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3450205B2 (en) |
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| JP2006336086A (en) * | 2005-06-03 | 2006-12-14 | Jfe Steel Kk | Method for blowing synthetic resin material into blast furnace |
| EP1939305A1 (en) * | 2006-12-29 | 2008-07-02 | L'AIR LIQUIDE, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude | Process for making pig iron in a blast furnace |
| WO2010065814A1 (en) * | 2008-12-05 | 2010-06-10 | Air Products And Chemicals, Inc. | Blast furnace iron production with integrated power generation |
| JP2012188743A (en) * | 2010-12-27 | 2012-10-04 | Jfe Steel Corp | Method for operating blast furnace |
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| JP2017222902A (en) * | 2016-06-15 | 2017-12-21 | Ｊｆｅスチール株式会社 | Lance |
| CN114657294A (en) * | 2022-03-31 | 2022-06-24 | 北京科技大学 | Experimental method and device for simulating combustion of blast furnace injection fuel |
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|---|---|---|---|---|
| JP2006336086A (en) * | 2005-06-03 | 2006-12-14 | Jfe Steel Kk | Method for blowing synthetic resin material into blast furnace |
| EP1939305A1 (en) * | 2006-12-29 | 2008-07-02 | L'AIR LIQUIDE, Société Anonyme pour l'Etude et l'Exploitation des Procédés Georges Claude | Process for making pig iron in a blast furnace |
| WO2008080922A2 (en) * | 2006-12-29 | 2008-07-10 | L'air Liquide Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude | Process for making pig iron in a blast furnace |
| WO2008080922A3 (en) * | 2006-12-29 | 2008-09-12 | Air Liquide | Process for making pig iron in a blast furnace |
| US8557173B2 (en) | 2007-12-06 | 2013-10-15 | Air Products And Chemicals, Inc. | Blast furnace iron production with integrated power generation |
| US8133298B2 (en) | 2007-12-06 | 2012-03-13 | Air Products And Chemicals, Inc. | Blast furnace iron production with integrated power generation |
| WO2010065814A1 (en) * | 2008-12-05 | 2010-06-10 | Air Products And Chemicals, Inc. | Blast furnace iron production with integrated power generation |
| JP2012188743A (en) * | 2010-12-27 | 2012-10-04 | Jfe Steel Corp | Method for operating blast furnace |
| WO2013094229A1 (en) | 2011-12-21 | 2013-06-27 | Ｊｆｅスチール株式会社 | Blast furnace operation method |
| KR20140109963A (en) | 2011-12-21 | 2014-09-16 | 제이에프이 스틸 가부시키가이샤 | Blast furnace operation method |
| EP2796566A1 (en) * | 2011-12-21 | 2014-10-29 | JFE Steel Corporation | Blast furnace operation method |
| EP2796566A4 (en) * | 2011-12-21 | 2015-12-02 | Jfe Steel Corp | Blast furnace operation method |
| EP2796566B1 (en) | 2011-12-21 | 2018-08-29 | JFE Steel Corporation | Blast furnace operation method |
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| WO2022194932A1 (en) * | 2021-03-19 | 2022-09-22 | Küttner Gmbh & Co. Kg | Method for injecting a pulverulent replacement reducing agent and a reducing gas into a blast furnace |
| CN114657294A (en) * | 2022-03-31 | 2022-06-24 | 北京科技大学 | Experimental method and device for simulating combustion of blast furnace injection fuel |
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