JPS6296607A - Blast furnace operation method for blowing slack into furnace - Google Patents

Abstract

PURPOSE:To control an in-furnace gas distribution and to make stable operation of a blast furnace by changing the grain size of the slack or slack slurry to be blown through tuyeres in accordance with the information on the temp. of the blast furnace body or in the furnace. CONSTITUTION:Coal supplied from a raw material feeder 7 is ground by a coal grinding mill 1 to form slack which is then prepared into a slurry in an agitating tank 16 via a storage tank 2. The slurry is blown by a pump 5 through the tuyere 4 into the blast furnace 3. The above-mentioned feeder 7 and the mill 1 are controlled by a control device 6 in accordance with the information on various temps. such as the in-furnace temp. measured by a furnace top sonde 9, furnace body brick temp. 8 measured by the thermocouples embedded into the bricks, and temp. difference between thermometers 11, 12 for feed and discharge water of a stave 10 for cooling the furnace body as measured by a detector 13, by which the supply rate of the coal and the grain size distribution of the slack are changed. The grain size distribution of the slack in the slurry is thereby changed and the combustion in front of the tuyere 4 is controlled, by which the in-furnace gas distribution is controlled.

Description

【発明の詳細な説明】 （産業上の利用分野） ゛　本発明は、粉炭を炉内に吹き込む高炉操業方法に関
し、特に本発明は吹き込まれる粉炭の粒度を変化するこ
とによって炉内ガス分布を制御し、高炉の安定操業を達
成する高炉操業方法に関する。Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method of operating a blast furnace in which pulverized coal is injected into a furnace. The present invention also relates to a blast furnace operating method that achieves stable blast furnace operation.

（従来の技術） 高炉操業において炉内ガス分布の調整は最も重要な項目
である。ガス分布の調整は高炉上部においてムーバブル
アーマ−プレート等を利用して炉内装入物分布を制御す
る方法と、後述する羽口前条件（例えば羽口先端速度）
で制御する方法とがある。高炉々頂部でのムーバブルア
ーマ−プレートによるコークス、鉱石等の装入物分布制
御の場合は炉内ガス流の制御に限界があるのに対し、羽
目前条件の制御は炉内に入るガスの流れを直接的に制御
するため、ガス分布制御上短時間のうちに所期の状態と
することができる利点があり、制御が容易である。(Prior Art) Adjustment of gas distribution in the furnace is the most important item in blast furnace operation. The gas distribution can be adjusted by controlling the distribution of the contents in the furnace using a movable armor plate, etc. in the upper part of the blast furnace, and by adjusting the pre-tuyere conditions (e.g. tuyere tip speed), which will be described later.
There is a way to control it. In the case of controlling the distribution of charges such as coke and ore using movable armor plates at the top of blast furnaces, there is a limit to the control of the gas flow in the furnace, whereas in the case of controlling the immediate conditions, the flow of gas entering the furnace is limited. Since the gas distribution is directly controlled, there is an advantage that the desired state can be achieved in a short time in terms of gas distribution control, and the control is easy.

羽口前条件の制御方法としては従来、吹き込みスラリー
の水分濃度を調整する方法が特開昭５７−２９５０７号
により開示されており、このほか送風温度を変更する方
法、送風湿分を変更する方法等が公知である。As a conventional method for controlling the conditions before the tuyere, a method of adjusting the water concentration of the blown slurry has been disclosed in JP-A No. 57-29507, as well as a method of changing the air temperature and a method of changing the air humidity. etc. are publicly known.

前述の羽目前条件を制御する方法によれば、装入物の分
布制御方法では８〜ｌＯ時間の時間が必要であるの拠対
し、２〜４時間の短時間でガス分布の制御が可能となる
。According to the method of controlling the immediate conditions described above, it is possible to control the gas distribution in a short time of 2 to 4 hours, whereas the charge distribution control method requires 8 to 10 hours. Become.

（発明が解決しようとする問題点） しかしながら前述の羽口前における条件の変更手段は高
炉操業に影響を及ぼす他の因子に影響を及ぼす、すなわ
ち前述の方法では目標とする羽口前条件の制御を達成し
得たとしても、それに伴って高炉への合計入熱量を変化
させることになり、この変化に伴って、他の反応因子に
影響を与える。(Problem to be Solved by the Invention) However, the above-mentioned means for changing the conditions before the tuyere affects other factors that affect the blast furnace operation. Even if this could be achieved, the total amount of heat input to the blast furnace would change accordingly, and this change would affect other reaction factors.

例えば送＆温度を低下する手段によって、カス分布の調
整ができたとしても、入熱量の変化から高炉に熱的な影
響を与え、溶銑温度が低下し、溶銑温度の低下と共に硫
黄分が上昇する等の弊害が生じる。また送風湿分の変更
又はスラリー濃度の変更によってガス分布の調整を行っ
ても、前述の場合と同様に入熱量の変化によって高炉へ
熱的な影響を与えるので、ガス分布の制御が達成できて
も、それに伴って変動する入熱量の変化に対しては何ら
の手段をと９得ないところに問題が残されていた。For example, even if the scum distribution can be adjusted by reducing the feed and temperature, changes in heat input will have a thermal effect on the blast furnace, causing the hot metal temperature to drop, and as the hot metal temperature falls, the sulfur content will rise. Such adverse effects may occur. Furthermore, even if the gas distribution is adjusted by changing the blast humidity or the slurry concentration, the change in the amount of heat input will have a thermal effect on the blast furnace, as in the case described above, so the control of the gas distribution cannot be achieved. However, the problem remains that no measures can be taken to deal with the accompanying changes in the amount of heat input.

（問題点を解決するための手段） 本発明は、従来の方法の有する欠点ならびに問題点を除
去、改善することのできる粉炭を炉内に吹き込む高炉操
業方法を提供することを目的とするものであり、特許請
求の範囲記載の粉炭を炉内に吹き込む高炉操業方法を提
供することによって前記目的を達成することができる。(Means for Solving the Problems) An object of the present invention is to provide a method for operating a blast furnace in which powdered coal is injected into the furnace, which can eliminate and improve the drawbacks and problems of conventional methods. The above object can be achieved by providing a method for operating a blast furnace in which powdered coal is blown into a furnace as described in the claims.

すなわちこの発明は羽口より粉炭もしくは粉炭スラリー
を炉内に吹き込んで操業を行う高炉操業方法において、
高炉々体又は炉内の温度情報に基づき、前記粉炭のもし
くは粉炭スラリー中の粉炭の粒度を変化させ、炉内ガス
分布を制御することを特徴とする粉炭を炉内に吹き込む
高炉操業方法に関する。That is, this invention provides a blast furnace operating method in which powdered coal or powdered coal slurry is injected into the furnace through the tuyere.
The present invention relates to a blast furnace operating method for injecting pulverized coal into a furnace, characterized in that the particle size of the pulverized coal or the pulverized coal in a pulverized coal slurry is changed based on temperature information in the blast furnace body or inside the furnace to control gas distribution in the furnace.

以下本発明の詳細な説明する。The present invention will be explained in detail below.

本発明の粉炭吹き込み手段は従来より公知である粉炭と
重油の混合物である００Ｍ燃料を使用するとき、粉炭と
水又はメタノールとの混合物、又は気送により搬送する
粉炭等の粉炭吹き込み手段に適用することができる。こ
れらの手段はいずれも粉炭を使用するので、コスト面で
は有利であり、取扱い方法も優れているが、前述の通抄
、従来炉況に応じ吹き込み量を増減したり、粉炭含有量
を変化させているが、吹き込み量を増減すると高炉内へ
の入熱量が変化する問題があり、入熱量な一定とするた
め粉炭の吹き込み量を一定に維持すると、ガス分布の制
御はできない。なお、以下の説明は、コスト的な面、取
扱いの面で優れろ粉炭と水のスラリーであるＣＷＭ　＠
料を例にとって説明する。The pulverized coal blowing means of the present invention is applicable to a pulverized coal blowing means such as a mixture of pulverized coal and water or methanol, or pulverized coal conveyed by pneumatic conveyance, when using 00M fuel, which is a mixture of pulverized coal and heavy oil, which is conventionally known. be able to. All of these methods use pulverized coal, so they are advantageous in terms of cost and have excellent handling methods. However, there is a problem in that increasing or decreasing the amount of blown coal changes the amount of heat input into the blast furnace, and if the amount of pulverized coal blown is kept constant in order to keep the amount of heat input constant, the gas distribution cannot be controlled. The following explanation is about CWM, which is a slurry of pulverized coal and water that is superior in terms of cost and handling.
This will be explained using the example of fees.

本発明の方法によれば高炉に粉炭スラリーな吹き込むと
き、高炉情報に基づいて、スラリー製造用ミルの運転方
法、例えば原料供給量、回転数を変化させて、スラリー
の粒度分布を変化させ、スラリーの羽目での燃焼速度を
変化させ、入熱量を一定とするためスラリー中の混合割
合は変化させないで、炉内ガス分布を制御する。　　　
　゛こ′！、にいう高炉情報とは炉況の把握手段として
炉体のレンガ温度、炉頂部のガス温度、或は炉体冷却用
ステーブの給排水温度等の検出器から採取される情報を
さし、これら情報は炉壁レンガ内に埋設された熱電対、
炉頂部に設けられた炉頂ゾンデ又は炉頂より装入物表面
の温度を観察可能な赤外線検出器を用いてＣＲＴ表示し
ているサーモピュアシステム、ステーブの給排水の水温
度等の既設の炉況把握装置による測定値によって得られ
る。According to the method of the present invention, when pulverized coal slurry is injected into a blast furnace, the operation method of the slurry production mill, for example, the feed rate of raw materials and the rotation speed, is changed to change the particle size distribution of the slurry, based on the blast furnace information. The gas distribution in the furnace is controlled without changing the mixing ratio in the slurry in order to keep the heat input constant by changing the combustion rate in the process.
゛ko′! The blast furnace information referred to in , refers to the information collected from detectors as a means of understanding the furnace condition, such as the brick temperature of the furnace body, the gas temperature at the top of the furnace, or the water supply and drainage temperature of the furnace body cooling stave. is a thermocouple buried in the furnace wall brick,
Existing furnace conditions such as the Thermopure system, which uses a CRT display using a top sonde installed at the top of the furnace or an infrared detector that can observe the temperature of the charge surface from the top of the furnace, and the water temperature of the stave water supply and drainage. Obtained by measurements with a grasping device.

周知の如くガス分布が炉壁側指向である周辺流化すれば
炉体レンガ温度と周辺部のガス温度が上昇し、サーモピ
ュアシステムでも炉壁側に沿う面の赤外線強度が増加す
る等前記測定値が高くなる。As is well known, if the gas distribution is oriented toward the furnace wall, and if it becomes a peripheral flow, the temperature of the furnace brick and the gas temperature in the surrounding area will rise, and even in the Thermopure system, the infrared intensity of the surface along the furnace wall will increase, etc. The value becomes higher.

一方ガス分布が中心流化すれば、炉内ガスは中央部を多
く流れる結果、炉壁面側の温度等が低下し、炉の中央部
の温度が上昇し、前記の炉体レンガ温度等の測定値が低
下する。従って前記温度測定値の変化から、ガス分布が
把握でき、測定値と予め設定した値との差異によって、
炉内ガス分布の変化及び変化量を知ることができる。On the other hand, if the gas distribution becomes centered, the gas in the furnace will flow more through the center, which will lower the temperature on the furnace wall side and increase the temperature at the center of the furnace, causing the temperature of the furnace bricks to be measured as described above. value decreases. Therefore, the gas distribution can be understood from the change in the temperature measurement value, and the difference between the measurement value and the preset value allows
Changes and amount of change in gas distribution in the furnace can be known.

次に本発明を図面によって更に詳細に説明する。Next, the present invention will be explained in more detail with reference to the drawings.

図は本発明の配置構成図であって、１は石炭破砕ミル、
２は粉砕後の石炭の貯蔵タンク、３は高炉、４は高炉羽
口、５は粉炭スラリーを羽口４に供給するポンプ、７は
高炉情報に基づく石炭の原料供給装置、６は石炭破砕ミ
ルを制御し石炭粒度を変更する制御装置、８は炉体レン
ガに埋設した温度計からのレンガ温度信号、９は炉頂ゾ
ンデ、１０は炉体冷却用ステーブ、１１．１２はステー
ブ１０に供給されている冷却水の給排水温度計、１３は
給排水温度計１１＋１２の温度差を検出する析出器１４
は粉炭の払出し量調節弁、１５は粉炭スラリー中の水分
値を一定とする水量調節弁、Ｉ６は払出調節弁１４より
払出された粉炭と、水ｆｉ：調節弁１５とから排出され
た水とを攪拌する攪拌槽、１７は粉炭スラリーの攪拌機
である。The figure is a layout configuration diagram of the present invention, in which 1 is a coal crushing mill;
2 is a storage tank for pulverized coal, 3 is a blast furnace, 4 is a blast furnace tuyere, 5 is a pump that supplies pulverized coal slurry to the tuyere 4, 7 is a coal raw material supply device based on blast furnace information, 6 is a coal crushing mill 8 is a brick temperature signal from a thermometer embedded in the furnace brick, 9 is a furnace top sonde, 10 is a stave for cooling the furnace body, and 11.12 is supplied to the stave 10. 13 is a precipitator 14 that detects the temperature difference between the cooling water supply and drainage thermometers 11+12.
15 is a water amount regulating valve that keeps the moisture value in the pulverized coal slurry constant; I6 is the pulverized coal discharged from the discharging regulating valve 14; and water fi: water discharged from the regulating valve 15. 17 is a stirrer for the powdered coal slurry.

粉炭スラリーの高炉吹き込みは、図に示す如くミル１で
粉炭を製造し、貯蔵タンク２に貯蔵し、次いで攪拌槽１
６で水と共に攪拌しスラリーとしポンプ５によって高炉
の羽口４に圧送する。Injecting powdered coal slurry into a blast furnace, as shown in the figure, powdered coal is produced in mill 1, stored in storage tank 2, and then transferred to stirring tank 1.
At 6, the mixture is stirred with water to form a slurry, and the pump 5 pumps the slurry to the tuyere 4 of the blast furnace.

予め炉体レンガ温度、炉頂ゾンデ、ステーブの給排水温
度計の温度差に対して操業上の管理値を設定しておくと
、炉頂ゾンデ９・炉体レンガ温度８、ステーブ排水温度
計の温度差検出器１３等からの信号を予め設定しておい
た管理値と比較してガス分布状態が判定できるので、制
御装置６によって、ミル１への原料供給量と、ミル１０
回転数を変化させて、スラリー中の粉炭の粒度分布を変
化させることによりガス分布状態の制御をおζなうこと
ができる。す々わち、スラリー中の粉炭の・　粒度分布
を大きくすれば羽口４前での燃焼が遅れ、ガス流分布は
中心流化する。一方粒度分布を小さくすれば羽目前での
燃焼速度が増大し、ガス流分布は周辺流化する。例えば
炉体レンガ温度８を高炉情報として利用する場合には炉
体レンガ温度８が管理値以下になれば、ミルｌの回転数
を上げ、・　原料の供給量を下げることによ妙、スラリ
ー粒度分布を小さくシ、炉内ガス流分布を周辺流化する
。By setting operational control values in advance for the temperature differences between the furnace body brick temperature, the furnace top sonde, and the stave water supply and drainage thermometer, the temperature of the furnace top sonde 9, furnace body brick temperature 8, and stave drainage thermometer can be set in advance. Since the gas distribution state can be determined by comparing the signal from the difference detector 13 etc. with a preset control value, the control device 6 can control the amount of raw material supplied to the mill 1 and the amount of raw material supplied to the mill 10.
The gas distribution state can be controlled by changing the rotation speed and changing the particle size distribution of the powdered coal in the slurry. In other words, if the particle size distribution of the powdered coal in the slurry is increased, combustion in front of the tuyere 4 will be delayed, and the gas flow distribution will become centered. On the other hand, if the particle size distribution is made smaller, the immediate combustion speed increases and the gas flow distribution becomes peripheral. For example, when using the furnace brick temperature 8 as blast furnace information, if the furnace brick temperature 8 falls below the control value, increase the rotation speed of the mill l, reduce the feed rate of raw materials, and adjust the slurry particle size. The gas flow distribution in the furnace is made to be a peripheral flow.

・　反対に炉体レンガ温度８が管理値を上回った場合に
は、・ミルｌの回転数を下げ、原料の供給量を増゛加す
るととＫよってスラリー粒度分布を大きくし、炉内ガス
流分布を中心流化する。・On the other hand, if the furnace brick temperature 8 exceeds the control value, ・lower the rotation speed of the mill and increase the amount of raw material supplied, which will increase the slurry particle size distribution and reduce the gas flow in the furnace. Center the distribution.

以下実施例によって具体的に説明する。This will be specifically explained below using examples.

（実施例） 本例は粉炭、水混合スラリーによって実施し、炉体冷却
用のステーブの給排水温度を信号として利用し、炉体か
ら抜熱した熱量を指針とした。(Example) This example was carried out using a mixed slurry of powdered coal and water, using the water supply and drainage temperature of a stave for cooling the furnace body as a signal, and using the amount of heat removed from the furnace body as a guideline.

使用した高炉は内容積２＋３００ｍ’級で、羽口数は３
３本である。炉体冷却用ステーブの給排水温度は通常３
０〜５０℃の範囲にある。The blast furnace used had an internal volume of 2 + 300 m' class, and the number of tuyeres was 3.
There are three. The temperature of the supply and drainage of the stave for cooling the furnace body is usually 3.
It is in the range of 0 to 50°C.

２００メツシユ以下が５０％以上である粉炭をスラリー
濃度５６％（重量％）で吹き込み高炉操業を継続した。Pulverized coal containing 50% or more of 200 meshes or less was injected into the slurry at a slurry concentration of 56% (wt%), and the blast furnace operation was continued.

この条件下において通常二百数十万ｋ　ｃａｌ　／　Ｋ
である炉体抜熱量が３００万ｋｃａｌ／Ｈに上昇した。Under these conditions, normally 200,000 kcal/K
The amount of heat extracted from the furnace body increased to 3 million kcal/H.

この時点でガス分布を中心流化するため、ミルの回転数
を低下し、石炭の供給量を増加し、粉炭を１００メツシ
ュ以下３０％以上、２００メツシュ以下２０％以下の粒
度とし、スラリー濃度１ｄ５６％（重量％）のま＼で羽
目に吹き込みを行い高炉操業を行った。At this point, in order to center the gas distribution, reduce the rotation speed of the mill, increase the amount of coal supplied, make the particle size of powdered coal 30% or less of 100 mesh or less, 20% or less of 200 mesh or less, and slurry concentration of 1d56 The blast furnace was operated by blowing into the siding at % (weight %).

この吹き込み後３時間後に炉体抜熱量は２００万ｋ　ｃ
ａｌ　／　Ｈに低下し、中心流化傾向に達していると判
断された。Three hours after this blowing, the amount of heat extracted from the furnace body was 2 million kc.
al/H, and it was judged that the central flow tendency had been reached.

なお粉炭の粒度分布を変更した両時点における溶銑の温
度差に成分には変化がなかった。It should be noted that there was no change in the composition due to the temperature difference of hot metal at both times when the particle size distribution of powdered coal was changed.

（発明の効果） 以上説明した如く、羽口より粉炭もしくは粉炭スラリー
を粒度を変化させ吹き込むことによって炉内ガス分布を
制御し、出銑量、炉況等を安定して操業することができ
るので、その効果は極めて大である。(Effects of the Invention) As explained above, by injecting powdered coal or powdered coal slurry with varying particle size through the tuyere, the gas distribution in the furnace can be controlled and the operation can be performed stably with regard to the amount of iron tapped and the furnace conditions. , the effect is extremely large.

【図面の簡単な説明】[Brief explanation of drawings]

図は本発明の配置構成図である。 １・・・ミル、２・・・貯蔵タンク、３・・・高炉、４
・・・羽口、５・・・スラリーポンプ、６・・・制御装
置、７・・・原料供給装置、８・・・炉体レンガ温度、
９・・・炉頂ゾンデ、１０・・・ステーブ、１１．１２
・・・給排水温度計、１３・・・検出器、１４・・・調
節弁、１５・・・水量調節弁、１６・・・攪拌槽、１７
・・・攪拌機、１８・・・モータ。The figure is a layout configuration diagram of the present invention. 1... Mill, 2... Storage tank, 3... Blast furnace, 4
... Tuyere, 5... Slurry pump, 6... Control device, 7... Raw material supply device, 8... Furnace brick temperature,
9... Furnace top sonde, 10... Stave, 11.12
... Water supply and drainage thermometer, 13 ... Detector, 14 ... Control valve, 15 ... Water flow control valve, 16 ... Stirring tank, 17
... Stirrer, 18... Motor.

Claims (1)

【特許請求の範囲】[Claims] 羽口より粉炭もしくは粉炭スラリーを炉内に吹き込んで
操業を行う高炉操業方法において：高炉々体又は炉内の
温度情報に基づき、前記粉炭のもしくは粉炭スラリー中
の粉炭の粒度を変化させ、炉内ガス分布を制御すること
を特徴とする粉炭を炉内に吹き込む高炉操業方法。In a blast furnace operation method in which pulverized coal or pulverized coal slurry is injected into the furnace through a tuyere, the particle size of the pulverized coal or the pulverized coal in the pulverized coal slurry is changed based on the temperature information of the blast furnace bodies or inside the furnace. A blast furnace operating method in which powdered coal is injected into the furnace, which is characterized by controlling gas distribution.