JPH04301021A - Method for preventing formation of stuck material to nozzle in fluidized reduction furnace - Google Patents

Method for preventing formation of stuck material to nozzle in fluidized reduction furnace

Info

Publication number
JPH04301021A
JPH04301021A JP6667791A JP6667791A JPH04301021A JP H04301021 A JPH04301021 A JP H04301021A JP 6667791 A JP6667791 A JP 6667791A JP 6667791 A JP6667791 A JP 6667791A JP H04301021 A JPH04301021 A JP H04301021A
Authority
JP
Japan
Prior art keywords
reducing gas
nozzle
reduction furnace
gas
fluidized bed
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.)
Withdrawn
Application number
JP6667791A
Other languages
Japanese (ja)
Inventor
Tatsuhiko Egashira
江頭 達彦
Tetsuaki Yamamoto
山本 哲明
Satoru Suzuki
悟 鈴木
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 JP6667791A priority Critical patent/JPH04301021A/en
Publication of JPH04301021A publication Critical patent/JPH04301021A/en
Withdrawn legal-status Critical Current

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  • Manufacture Of Iron (AREA)

Abstract

PURPOSE:To improve the reduction efficiency of ores and the operability by introducing oxygen-incorporating gas into blown reducing gas into a fluidized bed reduction furnace, partially burning the reducing gas and raising the temp. of the reducing gas just before introducing to nozzles. CONSTITUTION:The circulating type fluidized bed reduction furnace 10 is constituted of a riser 3 and an outer part particle circulating device 6, and the upper part with a circulating introducing tube 7 and the lower part with a connecting tube 8, are connected, respectively. Introduction of inert carrier gas into the riser 3 is executed through an introducing tube 9, header 11 and permeabile nozzle supporting plate 12 and the introduction of the reducing gas is executed through an introducing tube 13, header 15 and nozzles 16. Then, air is introduced into the reducing gas through an introducing tube 17 and nozzles 18, and the reducing gas retained in the header 15 is partially burnt and the temp. is raised. By this method, the higher temp. reducing gas can be supplied into the fluidized bed reduction furnace 10 and the reducing efficiency and the operability are improved.

Description

【発明の詳細な説明】[Detailed description of the invention]

【0001】0001

【産業上の利用分野】本発明は、流動層還元炉を用いて
鉄鉱石を還元する設備に関する。
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to equipment for reducing iron ore using a fluidized bed reduction furnace.

【0002】0002

【従来の技術】従来の高炉による溶銑製造技術に替わる
ものとして、溶融還元法が注目を浴びている。この方法
は、粉鉱石の使用、一般炭の使用、コークス工程の省略
等により溶銑を安価に製造することを目的に開発されて
いる。また、溶融還元炉で発生した排ガスの還元力及び
熱を有効に利用するために、流動ガスとして流動層還元
炉に供給して原料鉱石を予熱、予備還元する方法も開発
されている。
BACKGROUND OF THE INVENTION The smelting reduction method is attracting attention as an alternative to the conventional method of producing hot metal using a blast furnace. This method has been developed with the aim of producing hot metal at low cost by using fine ore, steam coal, and omitting the coking process. In addition, in order to effectively utilize the reducing power and heat of the exhaust gas generated in the smelting reduction furnace, a method has also been developed in which the raw ore is preheated and pre-reduced by supplying it to the fluidized bed reduction furnace as a fluidized gas.

【0003】かかる流動層還元装置として、特開昭62
−269283号公報、特開平1−111807号公報
に開示されているように、側部に粉鉱石投入部と底部付
近に流動層形成用のキャリアガス導入部と後工程の溶融
還元において発生した還元性ガスを循環導入する還元ガ
ス導入部とを設けた流動層(ライザー)と、その外側に
サイクロンを介して粉体を循環するための粉体循環流動
部(ダウンカマー)とからなる循環型の流動層と、サイ
クロンで捕集した粒状の鉄鉱石をライザーに戻さない非
循環型の流動層がある。
[0003] As such a fluidized bed reduction device, Japanese Patent Application Laid-Open No. 1982
As disclosed in JP-A-269283 and JP-A-1-111807, there is a fine ore input part on the side, a carrier gas introduction part for forming a fluidized bed near the bottom, and reduction generated during melt reduction in the subsequent process. A circulating type consisting of a fluidized bed (riser) equipped with a reducing gas introduction section that circulates the reactive gas, and a powder circulation fluidization section (downcomer) that circulates the powder via a cyclone outside of the fluidized bed (riser). There are fluidized beds and non-circulating fluidized beds in which the granular iron ore collected by the cyclone is not returned to the riser.

【0004】この前工程の溶融還元炉において発生した
還元性ガスを導入して流動層還元炉で鉱石を還元するに
際しての問題点の一つとして、還元ガスが多量の金属ヒ
ュームやダストを含有しているために、それが析出して
ノズル内面に付着し、ノズルを閉塞して安定操業を阻害
するという問題がある。
[0004] One of the problems when introducing the reducing gas generated in the smelting reduction furnace in this previous step and reducing the ore in the fluidized bed reduction furnace is that the reducing gas contains a large amount of metal fumes and dust. Therefore, there is a problem in that it precipitates and adheres to the inner surface of the nozzle, clogging the nozzle and hindering stable operation.

【0005】従来、この付着物の形成による問題を回避
するための方法として、還元ガス吐出ノズルを冷却して
、金属質付着物とノズルを構成する耐火物との熱収縮率
の差を利用して、付着物をノズル内面から剥離し落下せ
しめることによって付着物によるヘッド圧の低下や閉塞
を防止する方法がある。
Conventionally, as a method to avoid problems caused by the formation of deposits, the reducing gas discharge nozzle is cooled to take advantage of the difference in thermal contraction rate between the metallic deposits and the refractory material constituting the nozzle. There is a method of preventing a drop in head pressure and blockage caused by the deposits by peeling the deposits from the inner surface of the nozzle and letting them fall.

【0006】[0006]

【発明が解決しようとする課題】しかしながら、この冷
却による付着物を剥離しようとする方法は、導入する還
元ガスも冷却することになり、熱ロスが大きいばかりで
はなく、流動層還元炉内の温度低下を招き、そのため流
動層内での鉄鉱石の還元反応速度が低下して流動層還元
炉の生産性を低下させることになる。
[Problems to be Solved by the Invention] However, this method of peeling off deposits by cooling requires cooling the introduced reducing gas, which not only causes a large heat loss but also reduces the temperature inside the fluidized bed reduction furnace. As a result, the reduction reaction rate of iron ore in the fluidized bed decreases, resulting in a decrease in the productivity of the fluidized bed reduction furnace.

【0007】本発明は、このような還元ガス吹込みノズ
ルにおける付着物形成の問題を、付着後の処理というも
のではなく、付着物の形成そのものを抑制するための手
段を見出して解決することにその目的がある。
The present invention aims to solve the problem of the formation of deposits in reducing gas injection nozzles by finding a means for suppressing the formation of deposits itself, rather than by treating the deposits after the deposition. It has a purpose.

【0008】[0008]

【課題を解決するための手段】本発明は、吹込み還元ガ
ス中に酸素含有ガスを導入して還元ガスを部分燃焼せし
め、ノズル内を通過する還元ガスの温度をノズル導入直
前の温度より昇温せしめることを特徴とする。
[Means for Solving the Problems] The present invention introduces an oxygen-containing gas into the blown reducing gas to cause partial combustion of the reducing gas, thereby increasing the temperature of the reducing gas passing through the nozzle from the temperature immediately before introduction into the nozzle. It is characterized by warming.

【0009】還元ガス中に導入する酸素含有ガスとして
は、酸素富化ガスでも良いし、また、空気であっても良
い。
The oxygen-containing gas introduced into the reducing gas may be an oxygen-enriched gas or air.

【0010】また、部分燃焼のための酸素含有ガスは、
流動層の下方に形成された導入還元ガスヘッダーに導入
しても良いし、また、吹込みノズルの直前あるいはノズ
ルの入口付近から導入しても良い。
[0010] Furthermore, the oxygen-containing gas for partial combustion is
The reducing gas may be introduced into the introduction reducing gas header formed below the fluidized bed, or may be introduced just before the blowing nozzle or near the inlet of the nozzle.

【0011】[0011]

【作用】還元ガス中のダストとヒュームのノズル孔内壁
面への付着は、還元ガスがノズル内で冷却されて、還元
ガス中に含まれている気化分がそれぞれの析出温度に達
して析出して沈着したものが核となって成長する。本発
明は還元ガスを部分燃焼させることによって昇温し、ノ
ズル内の還元ガス温度をノズル入口における温度より高
く維持することによってガス中のヒューム、ダストの析
出温度よりも高く維持して付着物の形成と成長を防止す
る。
[Effect] The dust and fumes in the reducing gas adhere to the inner wall of the nozzle hole when the reducing gas is cooled in the nozzle and the vaporized components contained in the reducing gas reach their respective precipitation temperatures and precipitate. The material that is deposited becomes a nucleus and grows. The present invention raises the temperature of the reducing gas by partially burning it, and maintains the temperature of the reducing gas in the nozzle higher than the temperature at the nozzle inlet, thereby maintaining the temperature higher than the precipitation temperature of fumes and dust in the gas, thereby removing deposits. Prevents formation and growth.

【0012】0012

【実施例】以下本発明の実施態様として、図1に示す循
環型の流動層還元炉10のヘッダー部に酸素含有ガスと
して空気を導入した例を示す。
EXAMPLES As an embodiment of the present invention, an example will be shown below in which air is introduced as an oxygen-containing gas into the header section of the circulating fluidized bed reduction furnace 10 shown in FIG.

【0013】同図において、循環層還元炉10は鉱石供
給管1と還元鉱石排出管2を有するライザー3と、サイ
クロン4とダウンカマー5とから構成される外部粒子循
環装置6とからなり、それぞれライザー3と外部粒子循
環装置6とは上部においては循環導入管7によって、下
部においては連結管8で連結されている。9はライザー
3への不活性のキャリアガス導入管であって、同導入管
9からのキャリアガスは、一旦キャリアガスヘッダー1
1に導入され、そこから通気性のノズル支持板12を経
てライザー3内に噴出される。図示されない溶融還元炉
から、還元ガス導入管13によってライザー3内に導入
された還元ガスは、床底板14の下方に位置する還元ガ
スヘッダー15を経て、床底板14面に多数均一に配置
したノズル16からライザー3内に導入される。そして
、17は還元ガスヘッダー15内に滞留する還元ガスを
部分燃焼するために空気を導入する空気導入管を示す。 空気導入管17には、各ノズル16へ空気を分散供給す
るノズル18が取り付けられている。
In the figure, a circulating bed reduction furnace 10 consists of a riser 3 having an ore supply pipe 1 and a reduced ore discharge pipe 2, and an external particle circulation device 6 consisting of a cyclone 4 and a downcomer 5, each of which has a The riser 3 and the external particle circulation device 6 are connected at the upper part by a circulation introduction pipe 7 and at the lower part by a connecting pipe 8. 9 is an inert carrier gas introduction pipe to the riser 3, and the carrier gas from the introduction pipe 9 is once passed through the carrier gas header 1.
1 , from which it is ejected into the riser 3 via the breathable nozzle support plate 12 . The reducing gas introduced into the riser 3 through the reducing gas introduction pipe 13 from the melting reduction furnace (not shown) passes through the reducing gas header 15 located below the floor plate 14, and then passes through a large number of nozzles uniformly arranged on the floor plate 14 surface. 16 into the riser 3. Reference numeral 17 denotes an air introduction pipe through which air is introduced to partially combust the reducing gas remaining in the reducing gas header 15. A nozzle 18 that distributes and supplies air to each nozzle 16 is attached to the air introduction pipe 17 .

【0014】この図1に示す装置を用いて、本発明を実
施した。
The present invention was carried out using the apparatus shown in FIG.

【0015】その条件は、鉱石の処理量20T/H、還
元ガス量42,000Nm3 /H、還元ガスのヘッダ
ー内温度900℃で、還元ガスの組成はCO:41.5
%、CO2 :18.3%、H2 :17.0%、H2
 O:10.9%、N2 :12.1%である。
[0015] The conditions were: throughput of ore 20T/H, amount of reducing gas 42,000Nm3/H, temperature inside the header of reducing gas 900°C, and composition of reducing gas CO: 41.5.
%, CO2: 18.3%, H2: 17.0%, H2
O: 10.9%, N2: 12.1%.

【0016】このときのノズル内面へのダストの平均付
着速度は約17.5μm/Hであった。この装置では、
付着物が極端に発生する箇所では数100時間でノズル
閉塞のトラブルが生じていた。
[0016] At this time, the average rate of dust adhesion to the inner surface of the nozzle was about 17.5 μm/H. With this device,
In areas where a large amount of deposits were generated, troubles such as nozzle clogging occurred after several hundred hours.

【0017】前記設備の還元ガス吹込みノズル入口に空
気導入管17とノズル18を設け、ノズル入口に向けて
酸素含有ガスとして空気を供給した。
An air introduction pipe 17 and a nozzle 18 were provided at the inlet of the reducing gas blowing nozzle of the equipment, and air was supplied as an oxygen-containing gas toward the nozzle inlet.

【0018】還元ガス温度が900℃であり、着火温度
を充分に超えており、ノズル18から空気を供給すると
直ちに点火源なしでも点火して、安定した燃焼状態が得
られ、ノズル内での還元ガス温度を入口での還元ガス温
度よりも上昇させることができる。還元ガスのノズル内
の上昇温度と、ノズル内面への付着物の付着速度を測定
した結果を図2に示す。
The reducing gas temperature is 900° C., which is well above the ignition temperature, and as soon as air is supplied from the nozzle 18, it ignites even without an ignition source, and a stable combustion state is obtained. The gas temperature can be raised above the reducing gas temperature at the inlet. FIG. 2 shows the results of measuring the temperature rise inside the nozzle of the reducing gas and the rate of deposition of deposits on the inner surface of the nozzle.

【0019】還元ガス温度が50〜100℃上昇すると
、付着物の低減効果は大であった。これは、実施前の還
元ガス温度が、アルカリ金属化合物等の析出しやすい8
00〜900℃であり、この温度域以上になるように加
熱したことと、還元ガス加熱による不純物析出分圧の低
下による複合効果によるものである。
[0019] When the reducing gas temperature rose by 50 to 100°C, the effect of reducing deposits was significant. This is because the temperature of the reducing gas before implementation is such that alkali metal compounds are likely to precipitate.
00 to 900° C., and this is due to the combined effect of heating above this temperature range and lowering the partial pressure of impurity precipitation due to heating of the reducing gas.

【0020】このため、実施例では、酸素含有ガスとし
て空気を約4000Nm3 /H添加して、還元ガス温
度を約100℃上昇させた。この結果、実施前に比べて
付着量は約1/10程度まで低下した。
For this reason, in the example, about 4000 Nm 3 /H of air was added as the oxygen-containing gas to raise the reducing gas temperature by about 100°C. As a result, the amount of adhesion was reduced to about 1/10 of that before implementation.

【0021】なお、上記実施例においては、導入還元ガ
スへの酸素含有ガス導入部を還元ガスヘッダー部分にお
いて行う例について説明したが、ノズル本体の下方に直
接燃焼装置を用いても良い。要はノズル内を通過する還
元ガスの温度が流動層還元炉に導入される還元ガス温度
よりも高くなるようにすれば良い。
[0021] In the above embodiment, an example has been described in which the oxygen-containing gas introduction section for the introduced reducing gas is carried out in the reducing gas header section, but a direct combustion device may be used below the nozzle body. The point is that the temperature of the reducing gas passing through the nozzle should be higher than the temperature of the reducing gas introduced into the fluidized bed reduction furnace.

【0022】[0022]

【発明の効果】本発明によって、以下の効果を奏する。[Effects of the Invention] The present invention provides the following effects.

【0023】(1)導入還元ガスからの付着物によるノ
ズルの目詰まりを防止でき、流動層還元炉そのものの操
業が安定化する。
(1) Nozzle clogging due to deposits from the introduced reducing gas can be prevented, and the operation of the fluidized bed reduction furnace itself can be stabilized.

【0024】(2)還元ガスは冷却されず、逆に昇温さ
れるので還元効率が向上する。
(2) Since the reducing gas is not cooled but rather heated, the reduction efficiency is improved.

【0025】(3)流動層に導入される還元ガスの温度
が高くなり、還元反応性が高くなり、生産能力が向上す
る。
(3) The temperature of the reducing gas introduced into the fluidized bed becomes higher, the reduction reactivity becomes higher, and the production capacity is improved.

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

【図1】本発明の方法を実施した装置例を示す図である
FIG. 1 is a diagram showing an example of an apparatus implementing the method of the present invention.

【図2】本発明の効果を説明する図である。FIG. 2 is a diagram illustrating the effects of the present invention.

【符号の説明】[Explanation of symbols]

1  鉱石供給管 2  還元鉱石排出管 3  ライザー 4  サイクロン 5  ダウンカマー 6  外部粒子循環装置 7  循環導入管 8  連結管 9  キャリアガス導入管 10  循環型の流動層還元炉 11  キャリアガスヘッダー 12  ノズル支持板 13  還元ガス導入管 14  床底板 15  還元ガスヘッダー 16  ノズル 17  空気導入管 18  ノズル 1 Ore supply pipe 2 Reduced ore discharge pipe 3 Riser 4 Cyclone 5 Downcomer 6 External particle circulation device 7 Circulation introduction pipe 8 Connecting pipe 9 Carrier gas introduction pipe 10 Circulating fluidized bed reduction furnace 11 Carrier gas header 12 Nozzle support plate 13 Reducing gas introduction pipe 14 Floor bottom plate 15 Reducing gas header 16 Nozzle 17 Air introduction pipe 18 Nozzle

Claims (1)

【特許請求の範囲】[Claims] 【請求項1】  流動層還元炉への吹込み還元ガス中に
酸素含有ガスを導入して還元ガスを部分燃焼せしめ、ノ
ズル内を通過する還元ガスの温度をノズル導入直前の温
度より昇温せしめることを特徴とする流動層還元炉のノ
ズル付着物の形成防止方法。
[Claim 1] Oxygen-containing gas is introduced into the reducing gas blown into the fluidized bed reduction furnace to partially burn the reducing gas, and the temperature of the reducing gas passing through the nozzle is raised from the temperature immediately before introduction into the nozzle. A method for preventing the formation of nozzle deposits in a fluidized bed reduction furnace, characterized in that:
JP6667791A 1991-03-29 1991-03-29 Method for preventing formation of stuck material to nozzle in fluidized reduction furnace Withdrawn JPH04301021A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP6667791A JPH04301021A (en) 1991-03-29 1991-03-29 Method for preventing formation of stuck material to nozzle in fluidized reduction furnace

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP6667791A JPH04301021A (en) 1991-03-29 1991-03-29 Method for preventing formation of stuck material to nozzle in fluidized reduction furnace

Publications (1)

Publication Number Publication Date
JPH04301021A true JPH04301021A (en) 1992-10-23

Family

ID=13322797

Family Applications (1)

Application Number Title Priority Date Filing Date
JP6667791A Withdrawn JPH04301021A (en) 1991-03-29 1991-03-29 Method for preventing formation of stuck material to nozzle in fluidized reduction furnace

Country Status (1)

Country Link
JP (1) JPH04301021A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07188721A (en) * 1993-12-28 1995-07-25 Nkk Corp Method for pre-reducing iron ore and pre-reduction furnace for executing its method
KR100256338B1 (en) * 1995-12-05 2000-05-15 이구택 Fluidised bed reducing apparatus for iron ore powder
WO2002048407A1 (en) * 2000-12-12 2002-06-20 Voest-Alpine Industrieanlagenbau Gmbh & Co Method and device for increasing the thermal capacity of an at least partially reducing reaction gas

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH07188721A (en) * 1993-12-28 1995-07-25 Nkk Corp Method for pre-reducing iron ore and pre-reduction furnace for executing its method
KR100256338B1 (en) * 1995-12-05 2000-05-15 이구택 Fluidised bed reducing apparatus for iron ore powder
WO2002048407A1 (en) * 2000-12-12 2002-06-20 Voest-Alpine Industrieanlagenbau Gmbh & Co Method and device for increasing the thermal capacity of an at least partially reducing reaction gas

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