JP2001033173A - Exhaust gas treating facility of rotary hearth method and method for operating the same - Google Patents

Exhaust gas treating facility of rotary hearth method and method for operating the same

Info

Publication number
JP2001033173A
JP2001033173A JP11205888A JP20588899A JP2001033173A JP 2001033173 A JP2001033173 A JP 2001033173A JP 11205888 A JP11205888 A JP 11205888A JP 20588899 A JP20588899 A JP 20588899A JP 2001033173 A JP2001033173 A JP 2001033173A
Authority
JP
Japan
Prior art keywords
exhaust gas
temperature
dust collector
inlet
flow rate
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
Application number
JP11205888A
Other languages
Japanese (ja)
Other versions
JP4047495B2 (en
Inventor
Tetsuji Ibaraki
哲治 茨城
Takashi Hiromatsu
隆 廣松
Hiroshi Oda
博史 織田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Steel Corp
Original Assignee
Nippon Steel Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Nippon Steel Corp filed Critical Nippon Steel Corp
Priority to JP20588899A priority Critical patent/JP4047495B2/en
Publication of JP2001033173A publication Critical patent/JP2001033173A/en
Application granted granted Critical
Publication of JP4047495B2 publication Critical patent/JP4047495B2/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

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Classifications

    • CCHEMISTRY; METALLURGY
    • C21METALLURGY OF IRON
    • C21BMANUFACTURE OF IRON OR STEEL
    • C21B13/00Making spongy iron or liquid steel, by direct processes
    • C21B13/10Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
    • C21B13/105Rotary hearth-type furnaces

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Manufacture And Refinement Of Metals (AREA)
  • Manufacture Of Iron (AREA)
  • Tunnel Furnaces (AREA)
  • Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)

Abstract

PROBLEM TO BE SOLVED: To prevent closing of an exhaust gas route, a corrosion of a wall due to volatile impurities such as zinc, lead, chlorine or the like and acid corrosion of a dust collector, a burning damage of a filter or the like, by efficiently cooling and dust correcting the exhaust gas containing a large quantity of dusts at a high temperature in a reduction of an oxide metal using a rotary hearth method and recovering a waste heat. SOLUTION: The method for operating an exhaust gas treating facility of a rotary hearth method comprises the steps of sequentially installing a waste heat boiler 3 having an adhered duct removing unit, an exhaust gas cooler 4 by water scattering or air introducing valve, a heat exchanger 5 having an adhered dust removing unit, and a dust collector 5 on a route of the exhaust gas generated from a reducing furnace of the oxide metal having a rotary hearth; and regulating a flow rate of a refrigerant to be introduced to the route by using the cooler 4 with an exhaust gas flow rate and measured values of exhaust gas temperatures of a plurality of sites as control parameters.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【0001】[0001]

【発明の属する技術分野】本発明は、酸化金属の還元を
回転炉床法にて行う際に発生する高温の排ガスの冷却お
よび集塵を効率的に行い、廃熱回収を行うための設備に
関するものであり、また、排ガスダスト経路の閉塞と壁
の腐蝕の防止、および、集塵機の酸腐蝕やフィルターの
焼損等の防止をする技術を提供するものである。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a facility for efficiently cooling and collecting high-temperature exhaust gas generated when a metal oxide is reduced by a rotary hearth method and collecting waste heat. Another object of the present invention is to provide a technique for preventing blockage of an exhaust gas dust path and corrosion of a wall, and prevention of acid corrosion of a dust collector and burning of a filter.

【0002】[0002]

【従来の技術】還元鉄や合金鉄を製造するプロセスとし
ては各種のものがあるが、この内で、生産性の高いプロ
セスとして、回転炉床法が実施されている。回転炉床法
は、固定した耐火物の天井および側壁の下で、中央部を
欠いた円盤状の耐火物の炉床がレールの上を一定速度で
回転する型式の焼成炉(以下、回転炉と称す)を主体と
するプロセスであり、酸化金属の還元に用いられる。通
常、回転炉の炉床の直径は10メートルから50メート
ル、かつ、炉床の幅は2メートルから6メートルを有す
るものである。
2. Description of the Related Art There are various processes for producing reduced iron and alloyed iron. Among them, a rotary hearth method is used as a process with high productivity. The rotary hearth method is a type of firing furnace (hereinafter referred to as a rotary furnace) in which a disc-shaped refractory hearth lacking a central portion rotates at a constant speed on rails under a fixed refractory ceiling and side walls. This process is mainly used for the reduction of metal oxide. Usually, the diameter of the hearth of a rotary furnace is 10 to 50 meters, and the width of the hearth is 2 to 6 meters.

【0003】原料の酸化金属を含む粉体は、炭素系の還
元剤と混合された後、原料ペレットにされて、回転炉に
供給される。原料ペレットはこの炉床上に敷きつめられ
ており、原料ペレットが炉床上に静置されていることか
ら、原料ペレットが炉内で崩壊しづらいといった利点が
ある。その結果、耐火物上に粉化した原料が付着する問
題が無く、また、塊の製品歩留が高い。更に、生産性が
高く、安価な石炭系の還元剤や粉原料を使用できる、と
言った理由から、近年、実施される例が増加している。
回転炉床法は、高炉、転炉、電気炉から発生する製鉄ダ
ストや圧延工程でのシックナースラジの還元と不純物除
去の処理にも有効であり、ダスト処理プロセスとしても
使用され、資源リサイクルに有効なプロセスでもある。
[0003] A powder containing a metal oxide as a raw material is mixed with a carbon-based reducing agent, then formed into raw material pellets and supplied to a rotary furnace. The raw material pellets are laid on the hearth, and since the raw material pellets are left on the hearth, there is an advantage that the raw material pellets are hard to collapse in the furnace. As a result, there is no problem that the powdered raw material adheres to the refractory, and the product yield of lumps is high. Further, in recent years, the number of practiced examples has been increased due to the fact that high productivity and inexpensive coal-based reducing agents and powder raw materials can be used.
The rotary hearth method is also effective in the reduction of iron sludge generated in blast furnaces, converters, and electric furnaces and in the reduction and removal of impurities in the rolling process of thinner sludge. It is also an effective process.

【0004】回転炉床法の操業の概略は以下の通りであ
る。まず、原料である鉱石やダスト、スラジの金属酸化
物にこの酸化物の還元に必要な量の炭素系還元剤をよく
混合した後、パンペレタイザー等の造粒機にて、平均水
分が約10質量%となるように、水をかけながら、数mm
から十数mmのペレットを製造する。原料の鉱石や還元剤
の粒径が大きい場合は、ボールミル等の粉砕機で粉砕し
た後に、混練して、造粒することが行われている。
[0004] The outline of the operation of the rotary hearth method is as follows. First, after a sufficient amount of a carbon-based reducing agent necessary for the reduction of this oxide is mixed with the ore, dust, and sludge metal oxides as raw materials, the average water content is reduced to about 10% by a granulator such as a pan pelletizer. While sprinkling with water so that it becomes mass%, several mm
To produce pellets of tens of mm. When the particle size of the ore and the reducing agent as the raw materials is large, they are pulverized by a pulverizer such as a ball mill, kneaded, and granulated.

【0005】このペレットは回転炉床上に層状に供給さ
れ、炉床上に敷込まれたペレットは急速に加熱され、5
分間から20分間、1300℃前後の高温で焼成され
る。この際に、ペレットに混合されている還元剤により
酸化金属が還元され、金属が生成する。還元剤中の固定
炭素分はほぼ酸化される金属と化合している酸素量で求
まる量である。炭素の反応としては、還元には、固定炭
素のみが関与して、その反応は一酸化炭素まで進行する
ものと近いものである。金属化率は還元される金属によ
り異なるが、鉄、ニッケル、マンガンでは、95%以
上、還元しづらいクロムでも50%以上となる。
The pellets are supplied in layers on a rotary hearth, and the pellets laid on the hearth are rapidly heated and
It is fired at a high temperature of around 1300 ° C. for 20 minutes to 20 minutes. At this time, the metal oxide is reduced by the reducing agent mixed in the pellet, and a metal is generated. The fixed carbon content in the reducing agent is an amount determined substantially from the amount of oxygen combined with the metal to be oxidized. As for the reaction of carbon, only fixed carbon is involved in the reduction, and the reaction is close to that progressing to carbon monoxide. The metallization ratio varies depending on the metal to be reduced, but is 95% or more for iron, nickel, and manganese, and 50% or more for chromium that is difficult to reduce.

【0006】この回転炉からは、還元剤である炭素と燃
料の重油や天然ガスの燃焼により、発生する二酸化炭素
と水蒸気を多量に含む高温の排ガスが発生する。この排
ガスは、原料1トン当たり2000Nm3から3000Nm3
排出される。この排ガスはダクト入口で、約1000℃
であり、炉内から発生したダストを含んでおり、排ガス
ダクトを経由して、水散布等の方法で冷却された後に、
集塵されて、大気に放散される。回転炉床法は、酸化金
属の還元反応に伴い、亜鉛、鉛、塩素等の不純物が揮発
除去されることから、比較的ダスト発生量の多いプロセ
スである。
[0006] From this rotary furnace, high-temperature exhaust gas containing a large amount of carbon dioxide and water vapor is generated by the combustion of carbon as a reducing agent and fuel heavy oil or natural gas. The exhaust gas, 3000 Nm 3 from the raw material per ton 2000 Nm 3
Is discharged. This exhaust gas is about 1000 ℃ at the duct entrance.
It contains dust generated from the furnace, and after being cooled by a method such as water spraying via an exhaust gas duct,
Collected and released to the atmosphere. The rotary hearth method is a process that generates a relatively large amount of dust because impurities such as zinc, lead, and chlorine are volatilized and removed along with a reduction reaction of a metal oxide.

【0007】[0007]

【発明が解決しようとする課題】前述した様に、回転炉
床法による金属の還元炉においては、ダストを含む大量
の排ガスが発生することから、効率的なガスの冷却方法
が求められていた。つまり、従来法においては、回転炉
から発生する排ガスは、高温であり、大量のダストを含
んでいることが理由で発生する技術的な問題が解決され
ておらず、排ガス経路の内面への排ガス内のダストの付
着を防止しつつ、効率的に排ガスを冷却する良い技術が
なかった。
As described above, in a metal reduction furnace using the rotary hearth method, a large amount of exhaust gas including dust is generated, so that an efficient gas cooling method has been required. . In other words, in the conventional method, the exhaust gas generated from the rotary furnace is at a high temperature, and the technical problem that occurs because of containing a large amount of dust has not been solved. There was no good technology to efficiently cool the exhaust gas while preventing the adhesion of dust inside.

【0008】回転炉からの高温の排ガスが保有する顕熱
量は、この回転炉の全投入エネルギーの30%から40
%になり、熱効率の良い操業のためには、排ガスの廃熱
回収は重要な役割がある。しかし、高温の排ガスの廃熱
回収を行なうとする際には、廃熱ボイラーや熱交換器の
伝熱面にダストが強固に付着したり、これらの表面の金
属を腐蝕したりする問題があった。その結果、従来法に
おいては、ボイラーや熱交換器の閉塞の問題から、短期
間の周期で、プラントを休止して、ダスト清掃を行うこ
とになり、設備の稼働率が低下していた。この問題があ
ることから、例えば、United States Patent 3,836,353
に見られるように、排ガスを急速に冷却すれば、この問
題を解決できることから、廃熱回収を行わないことが、
一般的であった。
The amount of sensible heat held by the high-temperature exhaust gas from the rotary furnace ranges from 30% to 40% of the total input energy of the rotary furnace.
%, And waste heat recovery of exhaust gas plays an important role for efficient operation. However, when conducting waste heat recovery of high-temperature exhaust gas, there is a problem that dust adheres firmly to the heat transfer surface of the waste heat boiler or heat exchanger and the metal on these surfaces is corroded. Was. As a result, in the conventional method, due to the problem of clogging of the boiler or the heat exchanger, the plant is stopped and the dust cleaning is performed in a short period, thereby reducing the operation rate of the equipment. Because of this problem, for example, United States Patent 3,836,353
As can be seen in this report, if the exhaust gas is cooled rapidly, this problem can be solved.
Was common.

【0009】回転炉で、特に、廃熱回収を実施しづらい
のは、以下の理由である。回転炉から発生するダスト
は、酸化鉄等の原料が飛散したものだけでなく、アルカ
リ金属、亜鉛、鉛、その他の揮発性の金属と塩素や亜硫
酸基の陰イオン物質を多く含んでいる。特に、アルカリ
金属塩と亜鉛化合物は、排ガスダクト入口の1000℃
の部分では、蒸気で存在しており、これが排ガス温度が
低下すると共に、液体として析出を始める。
[0009] In a rotary furnace, it is particularly difficult to carry out waste heat recovery for the following reasons. Dust generated from the rotary furnace contains not only the scattered raw materials such as iron oxide but also a large amount of alkali metals, zinc, lead, other volatile metals, and anions of chlorine and sulfite groups. In particular, the alkali metal salt and the zinc compound are 1000 ° C at the exhaust gas inlet.
Is present as vapor, which starts to precipitate as a liquid as the exhaust gas temperature decreases.

【0010】この液体と固体で飛散したダスト成分が、
高粘性のエマルジョンを形成する。これが、排ガス経路
に付着するため、経路が狭くなった部分で閉塞を起こし
やすい問題があった。つまり、廃熱回収を行うため、ボ
イラーや熱交換器を設置すると、この部分で排ガス経路
が狭くなり、閉塞を起こしやすい。アルカリ金属塩の液
体は腐食性が強く、このエマルジョン付着部分での金属
腐食の問題もあった。したがって、これらの問題を解決
して、回転炉床法による還元炉において、廃熱回収を効
率的に行う排ガス処理設備と操業方法が求められてい
た。
The dust component scattered by the liquid and the solid is
Forms a highly viscous emulsion. Since this adheres to the exhaust gas path, there has been a problem that blockage is likely to occur in a narrowed path. That is, if a boiler or a heat exchanger is installed in order to perform waste heat recovery, the exhaust gas path becomes narrow at this portion, and blockage tends to occur. The liquid of the alkali metal salt is highly corrosive, and there is also a problem of metal corrosion at the portion where the emulsion adheres. Accordingly, there has been a demand for an exhaust gas treatment facility and an operating method for efficiently recovering waste heat in a reduction furnace using the rotary hearth method by solving these problems.

【0011】[0011]

【課題を解決するための手段】本発明は、(1)から
(8)の通りである。 (1)回転床を有する酸化金属の還元炉から発生する排
ガスの経路に、付着ダスト除去装置を有する廃熱ボイラ
ー3、水散布もしくは空気導入弁による排ガス冷却器
4、付着ダスト除去装置を有する熱交換器5、および、
集塵機6を、前記の順に設置してあり、排ガス流量と複
数の部位の排ガス温度の測定値を制御パラメーターとし
て、前記の排ガス冷却器4を用いて、排ガス経路に導入
する冷媒の流量を調整することを特徴とする回転炉床法
での排ガス処理設備。 (2)付着ダスト除去装置を有する熱交換器5とバグフ
ィルター式集塵機の間に、水散布もしくは空気導入弁に
よる排ガス冷却器13を有し、前記の排ガス冷却器13
での冷媒の流量を調整することを特徴とする(1)に記
載の回転炉床法での排ガス処理設備。 (3)回転床を有する酸化金属の還元炉から発生する排
ガスの経路に、付着ダスト除去装置を有する廃熱ボイラ
ー3、水散布もしくは空気導入弁による排ガス冷却器
4、付着ダスト除去装置を有する熱交換器5、および、
集塵機6を、前記の順に設置し、排ガス流量、熱交換器
入口温度の目標値と測定値の偏差、および、集塵機入口
温度の目標値と測定値の偏差を変数として、水散布もし
くは空気導入弁による排ガス冷却器4からの冷媒の流量
を制御することを特徴とする回転炉床法での排ガス処理
設備の操業方法。 (4)回転床を有する酸化金属の還元炉から発生する排
ガスの経路に、付着ダスト除去装置を有する廃熱ボイラ
ー3、水散布もしくは空気導入弁による排ガス冷却器
4、付着ダスト除去装置を有する熱交換器5、水散布も
しくは空気導入弁による排ガス冷却器13、および、集
塵機6を、前記の順に設置し、排ガス流量、熱交換器入
口温度の目標値と測定値の偏差、および、集塵機入口温
度の目標値と測定値の偏差を変数として、2基設置して
ある水散布もしくは空気導入弁による排ガス冷却器
(4、13)の片方または両方からの冷媒の流量を制御
することを特徴とする回転炉床法での排ガス処理設備の
操業方法。 (5)廃熱ボイラー3の入口の排ガス温度を800℃以
上、かつ、出口の排ガス温度を600℃以下、かつ、熱
交換器5入口の排ガス温度の目標値を400℃から55
0℃の間にすることを特徴とする(3)に記載の回転炉
床法での排ガス処理設備の操業方法。 (6)廃熱ボイラー3の入口の排ガス温度を800℃以
上、かつ、出口の排ガス温度を600℃以下、かつ、熱
交換器5入口の排ガス温度の目標値を400℃から55
0℃の間にすることを特徴とする(4)に記載の回転炉
床法での排ガス処理設備の操業方法。 (7)集塵機6としてバグフィルター式集塵装置を用い
る排ガス処理設備において、この入口の排ガス温度目標
値を120℃以上、190℃以下に制御することを特徴
とする(3)に記載の回転炉床法での排ガス処理設備の
操業方法。 (8)集塵機6としてバグフィルター式集塵装置を用い
る排ガス処理設備において、この入口の排ガス温度目標
値を120℃以上、190℃以下に制御することを特徴
とする(4)に記載の回転炉床法での排ガス処理設備の
操業方法。
The present invention is as described in (1) to (8). (1) In the path of exhaust gas generated from a metal oxide reduction furnace having a rotating bed, a waste heat boiler 3 having an attached dust removing device, an exhaust gas cooler 4 using water spraying or an air introduction valve, and a heat having an attached dust removing device. Exchanger 5, and
The dust collector 6 is installed in the above order, and the flow rate of the refrigerant introduced into the exhaust gas path is adjusted by using the exhaust gas cooler 4 using the measured values of the exhaust gas flow rate and the exhaust gas temperature at a plurality of locations as control parameters. Exhaust gas treatment equipment using the rotary hearth method. (2) The exhaust gas cooler 13 is provided between the heat exchanger 5 having the adhering dust removing device and the bag filter type dust collector by water spraying or an air introduction valve.
The exhaust gas treatment equipment using the rotary hearth method according to (1), wherein the flow rate of the refrigerant in the furnace is adjusted. (3) In the path of exhaust gas generated from a metal oxide reduction furnace having a rotating bed, a waste heat boiler 3 having an attached dust removing device, an exhaust gas cooler 4 using water spraying or an air introduction valve, and a heat having an attached dust removing device. Exchanger 5, and
The dust collector 6 is installed in the order described above, and a water spraying or an air introduction valve is set with the exhaust gas flow rate, the deviation between the target value of the heat exchanger inlet temperature and the measured value, and the deviation between the target value of the dust collector inlet temperature and the measured value as variables. Controlling the flow rate of the refrigerant from the exhaust gas cooler (4) by the rotary hearth method. (4) In the path of the exhaust gas generated from the metal oxide reduction furnace having the rotating bed, a waste heat boiler 3 having an attached dust removing device, an exhaust gas cooler 4 using water spraying or an air introduction valve, and a heat having an attached dust removing device. The exchanger 5, the exhaust gas cooler 13 using a water spraying or air introduction valve, and the dust collector 6 are installed in the order described above, the exhaust gas flow rate, the deviation between the target value and the measured value of the heat exchanger inlet temperature, and the dust collector inlet temperature. And controlling the flow rate of the refrigerant from one or both of the exhaust gas coolers (4, 13) using two water spraying or air introduction valves by using the deviation between the target value and the measured value as a variable. Operating method of exhaust gas treatment equipment by rotary hearth method. (5) The exhaust gas temperature at the inlet of the waste heat boiler 3 is 800 ° C. or more, the exhaust gas temperature at the outlet is 600 ° C. or less, and the target value of the exhaust gas temperature at the inlet of the heat exchanger 5 is 400 ° C. to 55 °.
The method for operating exhaust gas treatment equipment by the rotary hearth method according to (3), wherein the temperature is set to 0 ° C. (6) The exhaust gas temperature at the inlet of the waste heat boiler 3 is 800 ° C. or higher, the exhaust gas temperature at the outlet is 600 ° C. or lower, and the target value of the exhaust gas temperature at the inlet of the heat exchanger 5 is from 400 ° C. to 55 °
(4) The method for operating exhaust gas treatment equipment by the rotary hearth method according to (4), wherein the temperature is set to 0 ° C. (7) In the exhaust gas treatment equipment using a bag filter type dust collector as the dust collector 6, the target value of the exhaust gas temperature at the inlet is controlled to be 120 ° C. or more and 190 ° C. or less, The rotary furnace according to (3). Operating method of exhaust gas treatment equipment using the floor method. (8) In the exhaust gas treatment equipment using a bag filter type dust collector as the dust collector 6, the target value of the exhaust gas temperature at the inlet is controlled to 120 ° C. or more and 190 ° C. or less, The rotary furnace according to (4). Operating method of exhaust gas treatment equipment using the floor method.

【0012】[0012]

【発明の実施の形態】まず、回転炉床法の設備を図1に
示す。粉の酸化金属と石炭の混合物のペレットが回転炉
1の炉内の回転する炉床上に供給される。このペレット
は、高温雰囲気で還元され、炉外へ排出される。
DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows equipment for a rotary hearth method. Pellets of a mixture of powdered metal oxide and coal are fed onto a rotating hearth in the furnace of the rotary furnace 1. These pellets are reduced in a high-temperature atmosphere and discharged outside the furnace.

【0013】この時に発生した排ガスは、排ガス導入ダ
クト2から、排ガス処理設備に導入される。次に、廃熱
ボイラー3にて、排ガスが冷却されて、廃熱ボイラー3
からは蒸気が回収される。次に、排ガス冷却器4にて、
更に冷却される。ここでは、水噴霧式の冷却器を用いた
が、空気導入弁式の冷却器でも良い。この排ガスは、更
に、熱交換器5にて空気と熱交換して、冷却される。こ
の時に熱交換により加熱された空気は、回転炉1の燃焼
用空気やペレットの事前乾燥用熱風として用いられる。
次に、排ガスは、集塵機6にてダストを除去した後に、
誘引ファン7の動力にて、煙突8から大気に放散され
る。なお、この回転炉床法設備が設置してある工場で利
用できる蒸気量が少ない場合には、廃熱ボイラー3の前
に、排ガス冷却器を設置して、予め排ガスを冷却するこ
ともある。
The exhaust gas generated at this time is introduced into an exhaust gas treatment facility from an exhaust gas introduction duct 2. Next, in the waste heat boiler 3, the exhaust gas is cooled, and the waste heat boiler 3
Recovers steam. Next, in the exhaust gas cooler 4,
It is further cooled. Here, a water spray type cooler is used, but an air introduction valve type cooler may be used. This exhaust gas is further cooled by exchanging heat with air in the heat exchanger 5. At this time, the air heated by the heat exchange is used as combustion air for the rotary furnace 1 or hot air for pre-drying the pellets.
Next, the exhaust gas, after removing dust in the dust collector 6,
The power of the induction fan 7 causes the chimney 8 to emit the air to the atmosphere. If the amount of steam available at the factory where the rotary hearth method equipment is installed is small, an exhaust gas cooler may be installed before the waste heat boiler 3 to cool the exhaust gas in advance.

【0014】ダスト付着による伝熱面の汚れを防止して
廃熱を効率的に回収し、かつ、ダスト付着を防止するた
めには、廃熱ボイラー3と熱交換器5にダスト除去装置
を設置する。ダスト除去装置は種々のものがあるが、高
圧のガスや蒸気を吹き付けるスートブロー式や加振式の
ものが一般的である。
In order to prevent contamination of the heat transfer surface due to dust adhesion and efficiently recover waste heat and prevent dust adhesion, a dust removing device is installed in the waste heat boiler 3 and the heat exchanger 5. I do. Although there are various types of dust removing devices, a soot blow type or a vibrating type in which high-pressure gas or steam is blown is generally used.

【0015】前述したように、回転炉から発生する排ガ
ス中のダストには、アルカリ金属や亜鉛の化合物が存在
しており、この化合物は550℃程度以上の高温では、
融体であることがダスト付着の要因となっている。本発
明者らは、この解決のために、アルカリ金属や亜鉛の化
合物が蒸気から液体へと析出する温度域を廃熱ボイラー
で冷却することが重要であることを見いだした。
As described above, the dust in the exhaust gas generated from the rotary furnace contains a compound of an alkali metal or zinc, and this compound can be used at a high temperature of about 550 ° C. or more.
Melt is a factor of dust adhesion. The present inventors have found that in order to solve this problem, it is important to cool the temperature range in which the alkali metal or zinc compound precipitates from the vapor into the liquid with a waste heat boiler.

【0016】塩化ナトリウムや塩化亜鉛の飽和蒸気圧と
排ガス内の実蒸気圧の関係から、これらは、約800℃
以下で蒸気から析出を開始し、約600℃で析出を終了
する。この温度領域では,これらの化合物は液体であ
り、通常のダクト内では、例えば酸化鉄のような、他の
固体ダストと高粘性のエマルジョンを形成して、強固な
付着物を形成する。つまり、800℃から600℃の温
度領域を廃熱ボイラーで冷却することにより、高粘性の
エマルジョンの形成を防止することが重要であること
を、本発明者らは見いだした。
From the relationship between the saturated vapor pressure of sodium chloride or zinc chloride and the actual vapor pressure in the exhaust gas, these are approximately 800 ° C.
In the following, the precipitation is started from the vapor, and the precipitation is completed at about 600 ° C. In this temperature range, these compounds are liquid and form a viscous emulsion with other solid dusts, such as, for example, iron oxide, in a normal duct, forming a strong deposit. In other words, the present inventors have found that it is important to prevent the formation of a highly viscous emulsion by cooling the temperature range from 800 ° C. to 600 ° C. with a waste heat boiler.

【0017】その理由は以下の通りである。ボイラーチ
ューブの内部の蒸気や熱水との伝熱係数は、ガス側の外
面のものよりも非常に大きいことから、廃熱ボイラーチ
ューブのガス側の金属面の温度は、ボイラー内部の蒸気
もしくは熱水の温度とほぼ同等であり、わずかに5℃程
度高いだけである。通常の廃熱ボイラーの蒸気温度は、
500℃以下であり、ボイラーチューブのガス側の金属
面の温度は、505℃以下となる。塩化ナトリウムや塩
化亜鉛等の蒸気から析出してきたダスト成分の凝固温度
は、約550℃であり、この金属面温度では、これらは
ボイラーチューブ面で固体となる。その結果、高粘性の
エマルジョンを形成しなくなり、付着強度が低下するた
め、ダスト除去装置で容易にダストが落とせる。このよ
うに、排ガス温度は、廃熱ボイラーの入口で800℃以
上、出口で600℃以下が望ましい。
The reason is as follows. Since the coefficient of heat transfer with steam and hot water inside the boiler tube is much larger than that on the gas-side outer surface, the temperature of the metal surface on the gas side of the waste heat boiler tube depends on the steam or heat inside the boiler. It is almost equal to the temperature of water, only slightly higher by about 5 ° C. The steam temperature of a normal waste heat boiler is
The temperature is 500 ° C. or less, and the temperature of the gas-side metal surface of the boiler tube is 505 ° C. or less. The solidification temperature of dust components precipitated from vapors such as sodium chloride and zinc chloride is about 550 ° C., and at this metal surface temperature, they become solid on the boiler tube surface. As a result, a high-viscosity emulsion is not formed, and the adhesive strength is reduced, so that the dust can be easily removed by the dust removing device. Thus, the exhaust gas temperature is desirably 800 ° C. or higher at the inlet of the waste heat boiler and 600 ° C. or lower at the outlet.

【0018】更に、排ガスは、熱交換器5で熱回収され
るが、この部分の温度も重要な操業要因である。つま
り、熱交換器の排ガス温度が高すぎると、廃熱ボイラー
にて付着し終わらなかった塩化ナトリウムや塩化亜鉛等
は液体状態で、熱交換器金属面に付着して、閉塞や金属
腐食の問題を起こす。また、排ガス温度が低すぎると、
熱交換器の効率が悪化する。
Further, the exhaust gas is recovered in the heat exchanger 5, and the temperature of this portion is also an important operating factor. In other words, if the exhaust gas temperature of the heat exchanger is too high, sodium chloride, zinc chloride, etc., which has not adhered in the waste heat boiler, will adhere to the heat exchanger metal surface in a liquid state, causing blockage and metal corrosion. Cause Also, if the exhaust gas temperature is too low,
The efficiency of the heat exchanger deteriorates.

【0019】前述したように、塩化ナトリウムや塩化亜
鉛等は液体の凝固温度である550℃以下の温度であれ
ば、高粘性のエマルジョンを形成しないことから、付着
物の粘着性が弱く、かつ、腐蝕性も弱い。したがって、
熱交換器入口の排ガス温度は、550℃以下であること
が望ましい。また、この部分の排ガス温度が400℃以
下では、熱交換効率が悪くなるため、効率的な熱回収が
できなくなる。つまり、排ガス温度は、熱交換器の入口
で、550℃以下、かつ、400℃以上が望ましい。
As described above, sodium chloride, zinc chloride, and the like do not form a highly viscous emulsion at a temperature of 550 ° C. or lower, which is the solidification temperature of the liquid. Low corrosiveness. Therefore,
The exhaust gas temperature at the inlet of the heat exchanger is desirably 550 ° C. or less. Further, if the temperature of the exhaust gas in this portion is 400 ° C. or lower, the heat exchange efficiency deteriorates, so that efficient heat recovery becomes impossible. That is, the exhaust gas temperature at the inlet of the heat exchanger is desirably 550 ° C or lower and 400 ° C or higher.

【0020】そこで、熱交換器入口の排ガス温度を制御
することが重要となる。廃熱ボイラーと熱交換器の熱交
換効率は、休止点検時のチューブ表面清掃の後、経時的
に低下していく。その結果、廃熱ボイラーの出口の排ガ
ス温度は、時間とともに上がっていく。したがって、熱
交換器の入口温度を制御しようとした場合は、廃熱ボイ
ラー3と熱交換器5の間に、排ガス温度を調整する機能
を有する排ガス冷却器が必要となる。この理由で、水散
布装置もしくは空気導入弁の方式による排ガス冷却器4
が設置してある。
Therefore, it is important to control the temperature of the exhaust gas at the inlet of the heat exchanger. The heat exchange efficiency of the waste heat boiler and the heat exchanger decreases with time after the tube surface cleaning at the time of the stop inspection. As a result, the exhaust gas temperature at the outlet of the waste heat boiler rises with time. Therefore, when trying to control the inlet temperature of the heat exchanger, an exhaust gas cooler having a function of adjusting the exhaust gas temperature between the waste heat boiler 3 and the heat exchanger 5 is required. For this reason, the exhaust gas cooler 4 using a water spraying device or an air introduction valve is used.
Is installed.

【0021】また、熱交換器の後に設置してある集塵機
6は、湿式スクラバー、電気集塵機、バグフィルター等
を用いるが、各々の集塵機に於ける最適温度があり、こ
の部位の排ガス温度も制御する。特に、バグフィルター
の場合は、温度が190℃以上と高すぎると、フィルタ
ーが焼損し、また、温度が120℃以下と低すぎる場合
は、酸腐蝕が発生することから、この範囲に集塵機入口
の排ガス温度を制御する必要がある。
The dust collector 6 installed after the heat exchanger uses a wet scrubber, an electric dust collector, a bag filter, and the like. Each dust collector has an optimum temperature, and the temperature of the exhaust gas in this portion is also controlled. . In particular, in the case of a bag filter, if the temperature is too high as 190 ° C. or higher, the filter will be burned out, and if the temperature is too low as 120 ° C. or lower, acid corrosion will occur. It is necessary to control the exhaust gas temperature.

【0022】前記の排ガス冷却器4では、熱交換器入口
と集塵機入口の温度を所定の範囲内になるように、冷媒
である水や空気の導入流量を制御する。そのためには、
排ガス流量計測器9、熱交換器入口の排ガス温度の計測
器10、集塵機入口の排ガス温度の計測器11から得ら
れた計測値をもとに、各々の実測値と目標値の偏差を基
本パラメーターとして、制御機器12で制御演算を行
い、その演算結果により、排ガス冷却器4から排ガス経
路内へ導入される冷媒の流量を制御する。この時、制御
用の補助的な計測値として、廃熱ボイラー出口の排ガス
温度を測定して、これを制御パラメーターとして使用す
ることも有効である。
In the exhaust gas cooler 4 described above, the flow rates of water or air as a refrigerant are controlled so that the temperatures at the inlet of the heat exchanger and the inlet of the dust collector are within predetermined ranges. for that purpose,
Based on the measurement values obtained from the exhaust gas flow rate measuring device 9, the exhaust gas temperature measuring device 10 at the heat exchanger inlet, and the exhaust gas temperature measuring device 11 at the dust collector inlet, the deviation between the actual measured value and the target value is used as a basic parameter. The control operation is performed by the control device 12, and the flow rate of the refrigerant introduced from the exhaust gas cooler 4 into the exhaust gas path is controlled based on the operation result. At this time, it is also effective to measure the exhaust gas temperature at the outlet of the waste heat boiler as an auxiliary measurement value for control and use this as a control parameter.

【0023】制御方法としては、熱交換器の入口と集塵
機の入口の排ガス温度の目標値を設定して、実測された
温度との差分と排ガス流量から計算される排ガスの時間
当たりの熱容量から、必要な冷媒の流量を計算し、これ
をもとに、流量弁を制御して、排ガス温度調整を行う。
この時、制御のバラツキの大きさと熱交換機の熱交換量
の実績を考慮して、前記した温度範囲の内で、各々の排
ガス温度の目標値は選定される。
As a control method, a target value of the exhaust gas temperature at the inlet of the heat exchanger and the inlet of the dust collector is set, and the heat capacity per hour of the exhaust gas calculated from the difference between the actually measured temperature and the exhaust gas flow rate is calculated as follows. The required flow rate of the refrigerant is calculated, and the exhaust gas temperature is adjusted by controlling the flow valve based on the calculated flow rate.
At this time, the target value of each exhaust gas temperature is selected within the above-mentioned temperature range in consideration of the degree of control variation and the actual heat exchange amount of the heat exchanger.

【0024】また、例えば、ダスト発生の多い原料を使
用する場合などは、廃熱ボイラー3と熱交換器5の汚れ
が大きく、これらの部位での伝熱係数が大きく変化する
ことから、排ガス冷却器4のみで、熱交換器入口と集塵
機入口の排ガス温度を適正な範囲の制御できないことも
ある。この際は、図2に示すように、熱交換器5と集塵
機6の間に、もう一台の排ガス冷却器13を設置するこ
ともある。この際も、前記の計測値をもとに、制御機器
12で冷媒の流量を制御する。また、この際は、補助的
に、熱交換器出口の排ガス温度を計測し、これを制御パ
ラメーターをすることは、制御精度を向上させるために
有効である。
Further, for example, when a raw material that generates a lot of dust is used, the waste heat boiler 3 and the heat exchanger 5 are heavily contaminated, and the heat transfer coefficient at these portions changes greatly. In some cases, the exhaust gas temperature at the inlet of the heat exchanger and the inlet of the dust collector cannot be controlled in an appropriate range only by the vessel 4. In this case, another exhaust gas cooler 13 may be installed between the heat exchanger 5 and the dust collector 6, as shown in FIG. Also at this time, the flow rate of the refrigerant is controlled by the control device 12 based on the measured value. In this case, it is effective to measure the temperature of the exhaust gas at the outlet of the heat exchanger and to control the temperature of the exhaust gas in order to improve the control accuracy.

【0025】[0025]

【実施例】図1は、本発明を用いた回転炉床による還元
炉の排ガス処理設備の実施例である。この還元炉は、原
料ペレットを毎時20トン還元するもので、1100℃
の排ガスが、毎時47000ノルマル立方メートル発生
する。
FIG. 1 shows an embodiment of an exhaust gas treatment facility for a reduction furnace using a rotary hearth according to the present invention. This reduction furnace reduces raw material pellets by 20 tons per hour.
47000 normal cubic meters per hour are generated.

【0026】スートブロー装置付きの廃熱ボイラー3に
て、1100℃の排ガスは550℃まで冷却される。こ
の時、15気圧270℃の蒸気を毎時13トン回収する
ことができた。この排ガスは、水噴霧式の排ガス冷却器
4にて、470℃を目標値として、冷却され、スートブ
ロー装置付きの熱交換器5に送られた。この時の水噴霧
量は、毎時250kgであった。排ガス流量は安定してい
るため、熱交換器入口の排ガス温度は、455℃から、
490℃の範囲で制御された。
The exhaust gas at 1100 ° C. is cooled to 550 ° C. in the waste heat boiler 3 equipped with a soot blow device. At this time, 13 tons of steam at 15 atmospheres and 270 ° C. per hour could be recovered. This exhaust gas was cooled in a water spray type exhaust gas cooler 4 at a target value of 470 ° C. and sent to a heat exchanger 5 equipped with a soot blow device. The amount of water spray at this time was 250 kg per hour. Since the exhaust gas flow rate is stable, the exhaust gas temperature at the heat exchanger inlet is from 455 ° C.
The temperature was controlled in the range of 490 ° C.

【0027】その排ガスは、熱交換器5にて、145℃
から165℃に冷却され、バグフィルター式の集塵機6
で除塵されて、誘引ファン7、煙突8を経由して、大気
に放散された。熱交換器では、還元炉の燃焼用空気が加
熱されて、370℃の空気となって、還元炉1に送られ
た。
The exhaust gas is heated at 145 ° C. in the heat exchanger 5.
To 165 ° C, and bag filter type dust collector 6
, And was released to the atmosphere via the induction fan 7 and the chimney 8. In the heat exchanger, the combustion air in the reduction furnace was heated to be air at 370 ° C. and sent to the reduction furnace 1.

【0028】排ガス温度の制御は、熱交換器入口の排ガ
ス温度を第一制御目標として、この目標温度を極力高
く、かつ、集塵機入口の排ガス温度を目標の内に入るよ
うに設定する。この設定温度は、熱交換器の伝熱性能の
変化に影響を受けるため、熱交換器入口と集塵機入口の
排ガス温度の実績値により、補正計算できる制御ロジッ
クを構築した。
The exhaust gas temperature is controlled such that the exhaust gas temperature at the inlet of the heat exchanger is set as a first control target and the target temperature is set as high as possible, and the exhaust gas temperature at the inlet of the dust collector is within the target. Since this set temperature is affected by the change in the heat transfer performance of the heat exchanger, a control logic that can correct and calculate the actual exhaust gas temperature at the heat exchanger inlet and the dust collector inlet was constructed.

【0029】廃熱ボイラーでは、ダスト付着はさほどに
ひどくなく、1日に3回のブローによるダスト除去で十
分であった。また、熱交換器でも、1日に2回のブロー
によるダスト除去で十分であった。
In the waste heat boiler, dust adhesion was not so severe, and dust removal by blowing three times a day was sufficient. Also, with a heat exchanger, dust removal by blowing twice a day was sufficient.

【0030】この結果、燃焼用の空気の予熱により、燃
料エネルギー原単位が約9%低減でき、また、回収した
蒸気は、全投入熱量の11%に相当した。更に、従来法
に基づく設備では、排ガスの冷却に水や冷風を用いたこ
とから、冷却後の排ガス流量が増加して、誘引ファンの
電力も増加する問題があったが、本発明により、排ガス
流量の増加が大幅に減少して、誘引ファンの電力は、約
45%削減できた。
As a result, by preheating the air for combustion, the unit fuel energy consumption could be reduced by about 9%, and the recovered steam corresponded to 11% of the total heat input. Further, in the equipment based on the conventional method, since water or cold air is used for cooling the exhaust gas, there is a problem that the flow rate of the exhaust gas after cooling increases and the power of the attraction fan also increases. The increase in flow rate was greatly reduced, and the power of the induction fan could be reduced by about 45%.

【0031】つまり、本発明を用いた回転炉床法による
還元炉の排ガス処理設備によって、20%から25%の
エネルギー節約が行えた。更に、ダスト付着による排ガ
ス経路の閉塞の問題も解決して、従来では、2週間毎に
排ガス処理設備のダスト清掃を行っていたものが、2ヶ
月間の連続運転ができるようになった。
That is, by using the exhaust gas treatment equipment of the reduction furnace by the rotary hearth method using the present invention, an energy saving of 20% to 25% was achieved. Furthermore, the problem of blockage of the exhaust gas path due to dust adhesion has been solved. Conventionally, dust cleaning of exhaust gas treatment equipment has been performed every two weeks, but continuous operation for two months can be performed.

【0032】このように、本発明を用いることにより、
エネルギー効率の高い、かつ、稼働率の高い、酸化金属
の還元を行うことができて、金属製造の費用を大幅に低
減できた。
As described above, by using the present invention,
The reduction of metal oxide with high energy efficiency and high operation rate was able to be performed, and the cost of metal production was significantly reduced.

【0033】[0033]

【発明の効果】本発明によれば、回転炉床による還元炉
において、高温の排ガスから廃熱を回収して、蒸気と予
熱空気を得て、還元炉の熱効率を高めることができる。
また、ダスト付着による排ガス経路の閉塞の問題点も解
決することができ、従来法よりも高い稼働率で操業でき
るようになり、生産量が増加する効果も得られた。その
結果、還元金属の製造費を低減することができる。
According to the present invention, in a reduction furnace using a rotary hearth, waste heat is recovered from high-temperature exhaust gas to obtain steam and preheated air, thereby improving the thermal efficiency of the reduction furnace.
In addition, the problem of blockage of the exhaust gas path due to dust adhesion can be solved, the operation can be performed at a higher operation rate than the conventional method, and the effect of increasing the production amount can be obtained. As a result, the production cost of the reduced metal can be reduced.

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

【図1】本発明を用いた回転炉床による還元炉の排ガス
処理設備の図である。
FIG. 1 is a diagram of an exhaust gas treatment facility of a reduction furnace with a rotary hearth using the present invention.

【図2】本発明を用いた回転炉床による還元炉の排ガス
処理設備の図である。
FIG. 2 is a diagram of an exhaust gas treatment facility of a reduction furnace using a rotary hearth according to the present invention.

【符号の説明】[Explanation of symbols]

1 回転炉 2 排ガス導入ダクト 3 廃熱ボイラー 4 排ガス冷却器 5 熱交換器 6 集塵機 7 誘引ファン 8 煙突 9 排ガス流量計測器 10 交換器入口の排ガス温度の計測器 11 集塵機入口の排ガス温度の計測器 12 制御機器 13 排ガス冷却器(その2) DESCRIPTION OF SYMBOLS 1 Rotary furnace 2 Exhaust gas introduction duct 3 Waste heat boiler 4 Exhaust gas cooler 5 Heat exchanger 6 Dust collector 7 Induction fan 8 Chimney 9 Exhaust gas flow rate measuring device 10 Exhaust gas temperature measuring device at exchanger entrance 11 Exhaust gas temperature measuring device at dust collector entrance 12 Control equipment 13 Exhaust gas cooler (Part 2)

───────────────────────────────────────────────────── フロントページの続き (72)発明者 織田 博史 君津市君津1番地 新日本製鐵株式会社君 津製鐵所内 Fターム(参考) 4K001 AA10 BA02 BA05 CA23 GB09 GB10 GB11 4K012 DD09 DD10 4K050 AA04 BA02 CA08 CE07 DA06 EA04 EA08 4K056 AA11 BA06 CA02 DA13 DB05 DB12 FA06 FA08  ──────────────────────────────────────────────────続 き Continuing from the front page (72) Inventor Hiroshi Oda 1 Kimitsu, Kimitsu-shi Nippon Steel Corporation Kimitsu Works F-term (reference) 4K001 AA10 BA02 BA05 CA23 GB09 GB10 GB11 4K012 DD09 DD10 4K050 AA04 BA02 CA08 CE07 DA06 EA04 EA08 4K056 AA11 BA06 CA02 DA13 DB05 DB12 FA06 FA08

Claims (8)

【特許請求の範囲】[Claims] 【請求項1】 回転床を有する酸化金属の還元炉から発
生する排ガスの経路に、付着ダスト除去装置を有する廃
熱ボイラー、水散布もしくは空気導入弁による排ガス冷
却器、付着ダスト除去装置を有する熱交換器、および、
集塵機を、前記の順に設置してあり、排ガス流量と複数
の部位の排ガス温度の測定値を制御パラメーターとし
て、前記の排ガス冷却器を用いて、排ガス経路に導入す
る冷媒の流量を調整することを特徴とする回転炉床法で
の排ガス処理設備。
1. A waste heat boiler having an attached dust removing device, an exhaust gas cooler using water spraying or an air introduction valve, and a heat having an attached dust removing device in a path of exhaust gas generated from a metal oxide reduction furnace having a rotating bed. Exchanger, and
A dust collector is installed in the order described above, and using the exhaust gas flow rate and the measured values of the exhaust gas temperature at a plurality of parts as control parameters, using the exhaust gas cooler, adjusting the flow rate of the refrigerant introduced into the exhaust gas path. Exhaust gas treatment equipment using the rotary hearth method.
【請求項2】 付着ダスト除去装置を有する熱交換器と
バグフィルター式集塵機の間に、水散布もしくは空気導
入弁による排ガス冷却器を有し、前記の排ガス冷却器で
の冷媒の流量を調整することを特徴とする請求項1に記
載の回転炉床法での排ガス処理設備。
2. An exhaust gas cooler with a water spray or an air introduction valve is provided between a heat exchanger having an attached dust removing device and a bag filter type dust collector, and the flow rate of the refrigerant in the exhaust gas cooler is adjusted. The exhaust gas treatment equipment according to the rotary hearth method according to claim 1, wherein:
【請求項3】 回転床を有する酸化金属の還元炉から発
生する排ガスの経路に、付着ダスト除去装置を有する廃
熱ボイラー、水散布もしくは空気導入弁による排ガス冷
却器、付着ダスト除去装置を有する熱交換器、および、
集塵機を、前記の順に設置し、排ガス流量、熱交換器入
口温度の目標値と測定値の偏差、および、集塵機入口温
度の目標値と測定値の偏差を変数として、水散布もしく
は空気導入弁による排ガス冷却器からの冷媒の流量を制
御することを特徴とする回転炉床法での排ガス処理設備
の操業方法。
3. A waste heat boiler having an attached dust removing device, an exhaust gas cooler using water spraying or an air introduction valve, and a heat having an attached dust removing device in a path of exhaust gas generated from a metal oxide reduction furnace having a rotating bed. Exchanger, and
The dust collector is installed in the order described above, and the exhaust gas flow rate, the deviation between the target value and the measured value of the heat exchanger inlet temperature, and the deviation between the target value and the measured value of the dust collector inlet temperature as variables, are set by water spraying or air introduction valve. A method for operating an exhaust gas treatment facility by a rotary hearth method, comprising controlling a flow rate of a refrigerant from an exhaust gas cooler.
【請求項4】 回転床を有する酸化金属の還元炉から発
生する排ガスの経路に、付着ダスト除去装置を有する廃
熱ボイラー、水散布もしくは空気導入弁による排ガス冷
却器、付着ダスト除去装置を有する熱交換器、水散布も
しくは空気導入弁による排ガス冷却器、および、集塵機
を、前記の順に設置し、排ガス流量、熱交換器入口温度
の目標値と測定値の偏差、および、集塵機入口温度の目
標値と測定値の偏差を変数として、2基設置してある水
散布もしくは空気導入弁による排ガス冷却器の片方また
は両方からの冷媒の流量を制御することを特徴とする回
転炉床法での排ガス処理設備の操業方法。
4. A waste heat boiler having an attached dust removing device, an exhaust gas cooler using water spraying or an air introduction valve, and a heat having an attached dust removing device in a path of exhaust gas generated from a metal oxide reduction furnace having a rotating bed. An exchanger, an exhaust gas cooler with a water spray or air introduction valve, and a dust collector are installed in the order described above, and the exhaust gas flow rate, the deviation between the target value of the heat exchanger inlet temperature and the measured value, and the target value of the dust collector inlet temperature Exhaust gas treatment by the rotary hearth method, characterized by controlling the flow rate of refrigerant from one or both of the exhaust gas coolers by water spraying or air introduction valves, using the deviation of the measured value as a variable How the equipment operates.
【請求項5】 廃熱ボイラーの入口の排ガス温度を80
0℃以上、かつ、出口の排ガス温度を600℃以下、か
つ、熱交換器入口の排ガス温度の目標値を400℃から
550℃の間にすることを特徴とする請求項3に記載の
回転炉床法での排ガス処理設備の操業方法。
5. The exhaust gas temperature at the inlet of the waste heat boiler is set to 80.
The rotary furnace according to claim 3, wherein the exhaust gas temperature at the outlet is 0C or more, the exhaust gas temperature at the outlet is 600C or less, and the target value of the exhaust gas temperature at the inlet of the heat exchanger is 400C to 550C. Operating method of exhaust gas treatment equipment using the floor method.
【請求項6】 廃熱ボイラーの入口の排ガス温度を80
0℃以上、かつ、出口の排ガス温度を600℃以下、か
つ、熱交換器入口の排ガス温度の目標値を400℃から
550℃の間にすることを特徴とする請求項4に記載の
回転炉床法での排ガス処理設備の操業方法。
6. The exhaust gas temperature at the inlet of the waste heat boiler is set to 80.
5. The rotary furnace according to claim 4, wherein the exhaust gas temperature at the outlet is 0 ° C. or more, the exhaust gas temperature at the outlet is 600 ° C. or less, and the target value of the exhaust gas temperature at the inlet of the heat exchanger is between 400 ° C. and 550 ° C. 6. Operating method of exhaust gas treatment equipment using the floor method.
【請求項7】 集塵機としてバグフィルター式集塵装置
を用いる排ガス処理設備において、この入口の排ガス温
度目標値を120℃以上、190℃以下に制御すること
を特徴とする請求項3に記載の回転炉床法での排ガス処
理設備の操業方法。
7. The exhaust gas treatment equipment using a bag filter type dust collector as a dust collector, wherein the target exhaust gas temperature at the inlet is controlled to 120 ° C. or more and 190 ° C. or less. Operating method of exhaust gas treatment equipment by hearth method.
【請求項8】 集塵機としてバグフィルター式集塵装置
を用いる排ガス処理設備において、この入口の排ガス温
度目標値を120℃以上、190℃以下に制御すること
を特徴とする請求項4に記載の回転炉床法での排ガス処
理設備の操業方法。
8. An exhaust gas treatment system using a bag filter type dust collector as a dust collector, wherein the target exhaust gas temperature at the inlet is controlled to be 120 ° C. or more and 190 ° C. or less. Operating method of exhaust gas treatment equipment by hearth method.
JP20588899A 1999-07-21 1999-07-21 Operation method of rotary hearth exhaust gas treatment equipment Expired - Fee Related JP4047495B2 (en)

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