JPH0324225A - Oxygen enriching combustion method for continuous heating furnace - Google Patents
Oxygen enriching combustion method for continuous heating furnaceInfo
- Publication number
- JPH0324225A JPH0324225A JP1160132A JP16013289A JPH0324225A JP H0324225 A JPH0324225 A JP H0324225A JP 1160132 A JP1160132 A JP 1160132A JP 16013289 A JP16013289 A JP 16013289A JP H0324225 A JPH0324225 A JP H0324225A
- Authority
- JP
- Japan
- Prior art keywords
- oxygen
- ammonia
- heating furnace
- nox
- concn
- 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.)
- Pending
Links
- 239000001301 oxygen Substances 0.000 title claims abstract description 55
- 229910052760 oxygen Inorganic materials 0.000 title claims abstract description 55
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 title claims abstract description 54
- 238000010438 heat treatment Methods 0.000 title claims abstract description 26
- 238000009841 combustion method Methods 0.000 title claims description 5
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 84
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 42
- 238000002485 combustion reaction Methods 0.000 claims abstract description 23
- 239000007789 gas Substances 0.000 claims abstract description 23
- 238000000034 method Methods 0.000 claims abstract description 22
- 239000000571 coke Substances 0.000 claims abstract description 8
- 230000007613 environmental effect Effects 0.000 claims abstract description 6
- 239000000446 fuel Substances 0.000 claims abstract description 5
- 239000003795 chemical substances by application Substances 0.000 claims abstract description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N Nitric oxide Chemical compound O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 30
- 230000033228 biological regulation Effects 0.000 claims description 11
- 239000006227 byproduct Substances 0.000 claims description 11
- 230000003197 catalytic effect Effects 0.000 claims description 8
- 238000000746 purification Methods 0.000 claims description 3
- 230000000694 effects Effects 0.000 abstract description 11
- 238000007670 refining Methods 0.000 abstract description 5
- 230000001105 regulatory effect Effects 0.000 abstract description 5
- 230000003247 decreasing effect Effects 0.000 abstract 3
- 239000003054 catalyst Substances 0.000 abstract 2
- 239000002912 waste gas Substances 0.000 abstract 2
- 150000002926 oxygen Chemical class 0.000 abstract 1
- 238000006243 chemical reaction Methods 0.000 description 6
- 238000010586 diagram Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 3
- 239000007864 aqueous solution Substances 0.000 description 3
- NLXLAEXVIDQMFP-UHFFFAOYSA-N Ammonium chloride Substances [NH4+].[Cl-] NLXLAEXVIDQMFP-UHFFFAOYSA-N 0.000 description 2
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 235000011114 ammonium hydroxide Nutrition 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 239000002737 fuel gas Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- 230000003213 activating effect Effects 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000002440 industrial waste Substances 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012544 monitoring process Methods 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 231100001143 noxa Toxicity 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E20/00—Combustion technologies with mitigation potential
- Y02E20/34—Indirect CO2mitigation, i.e. by acting on non CO2directly related matters of the process, e.g. pre-heating or heat recovery
Landscapes
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
- Regulation And Control Of Combustion (AREA)
Abstract
Description
【発明の詳細な説明】
［発明の目的コ
（産業上の利用分野）
本発明は、連続加熱炉の酸素富化燃焼方法に関する．
（従来の技術）
加熱炉酸素富化は、燃焼用空気に酸素を添加し、酸素濃
度を高める技術である。酸素富化による加熱炉の熱効率
の向上は、専ら燃焼に寄与しないチッ素の排ガス中の分
圧を低下し持ち去る顕熱もその分少なくなることに起因
するものである。DETAILED DESCRIPTION OF THE INVENTION [Objective of the Invention (Industrial Application Field) The present invention relates to an oxygen-enriched combustion method for a continuous heating furnace. (Prior Art) Furnace oxygen enrichment is a technology that adds oxygen to combustion air to increase the oxygen concentration. The improvement in the thermal efficiency of a heating furnace due to oxygen enrichment is due to the fact that the partial pressure of nitrogen in the exhaust gas, which does not contribute to combustion, is reduced and the sensible heat carried away is also reduced accordingly.
しかし，酸素富化には一方でＮＯｘを増大させる弊害が
あり、実用化に至っていない。このため、最近の研究は
， いかにＮＯｘの上昇を抑制しながら酸素富化を行う
かに関心が移っている。公表された技術としては、例え
ば■２段燃焼式低ＮＯｘバーナを使用するもの、■排ガ
ス循環燃焼によるもの、■ＮＯＸａ度を常時監視し，規
制限界一杯まで酸素富化するもの等がある。However, oxygen enrichment has the disadvantage of increasing NOx, and has not been put to practical use. For this reason, recent research has focused on how to enrich oxygen while suppressing the rise in NOx. Examples of published technologies include (1) using a two-stage combustion type low NOx burner, (2) using exhaust gas circulation combustion, and (2) constantly monitoring the NOXa level and enriching with oxygen up to the regulatory limit.
また，排ガスからＮＯｘを除去する脱硝法によるものに
は、種々のものがある。この内、特に無触媒アンモニア
脱硝法によるものとして，特公昭５０−２３６６４号に
示される排ガス中チッ素酸化物消去法や特公昭５０−３
５９０８号に示される燃焼流出ガスのチッ素酸化物濃度
を減少させる方法がある。Furthermore, there are various denitrification methods for removing NOx from exhaust gas. Among these methods, the non-catalytic ammonia denitrification method is particularly known as the method for eliminating nitrogen oxides in exhaust gas shown in Japanese Patent Publication No. 50-23664 and the Japanese Patent Publication No. 50-3.
No. 5,908, there is a method for reducing the concentration of nitrogen oxides in combustion effluent gases.
これらの技術は、■触媒式アンモニア脱硝法と異なり，
Ｍ！１備費が非常に安価であり、かつ，反応系の圧損が
ないのでブロアー運転費もかからない，■特に一貫製鉄
所の場合、コークス炉ガス精製過程で生ずる副生アンモ
ニア（水溶液）をそのまま使用できるので，薬剤費が事
実上かからない，■加熱炉の排ガス温度が、この脱硝反
応に適した温度域（７５０〜１０００℃，但し，燃料種
によって多少異なる）にある，等の如く，一貫製鉄所の
加熱炉に対しては良く適合した特質を備えている．（発
明が解決しようとする課題）
しかしながら，上述の従来の技術によるものは、以下に
述べるように設備費あるいは運転費がかさみ特に既存の
炉に対しては投資採算が合わなかった．
■ ２段燃焼式バーナによる低ＮＯｘ化は、効果が小さ
い．また、既存の加熱炉に適用する場合はバーナ更新の
ために大きな設備投資が必要となる．
■ 排ガス環境による低ＮＯｘ化は、排ガス循環ダクト
，ブロアーの新設，バーナの更新等に大きな設備投資が
必要となる上に、ブロアーの運転費がかさむ．
（３） ＮＯＸの規制値一杯まで酸素富化する方法で
は，現行の規制値が厳しく、余裕がほとんどないため、
実祭上酸素富化はごく低い値までしかできない．
このように酸素富化を始めるに際し、例えば酸素配管費
などの投下した設備費の償却が困難であるのが実情であ
る。These technologies differ from the catalytic ammonia denitrification method,
M! 1 The equipment cost is very low, and there is no pressure loss in the reaction system, so there is no blower operating cost. Especially in the case of an integrated steelworks, the by-product ammonia (aqueous solution) produced in the coke oven gas purification process can be used as is. , There are virtually no chemical costs, ■ The exhaust gas temperature of the heating furnace is in the temperature range suitable for this denitrification reaction (750 to 1000 degrees Celsius, however, this varies depending on the fuel type), etc. It has characteristics that are well suited for furnaces. (Problems to be Solved by the Invention) However, as described below, the conventional technology described above increases equipment costs and operating costs, and is not profitable for investment, especially for existing furnaces. ■ The effect of reducing NOx using a two-stage combustion burner is small. Additionally, if applied to an existing heating furnace, a large capital investment will be required to update the burner. ■ Reducing NOx in the exhaust gas environment requires large capital investment in installing new exhaust gas circulation ducts, blowers, updating burners, etc., and also increases the operating costs of the blowers. (3) With the method of oxygen enrichment up to the NOx regulation value, the current regulation value is strict and there is almost no margin.
In practice, oxygen enrichment can only be achieved to a very low level. The reality is that when starting oxygen enrichment, it is difficult to amortize the equipment costs, such as oxygen piping costs.
本発明は、かかる点に鑑みてなされたものであり、同一
環境規制値下での富化し得る酸素濃度の限界値が高く、
しかも、酸素富化の際の設備投資を軽減させることがで
きる連続加熱炉の酸素富化燃焼方法を提供するものであ
る。The present invention has been made in view of this point, and the limit value of oxygen concentration that can be enriched under the same environmental regulation value is high,
Furthermore, the present invention provides an oxygen-enriched combustion method for a continuous heating furnace that can reduce equipment investment for oxygen enrichment.
［発明の構成］
（課題を解決するための手段）
本発明は、連続加熱炉の排ガス中のチッ素酸化物の濃度
を、コークス炉ガス精製工程の副生アンモニアからなる
脱硝剤による無触媒アンモニア脱硝法を適用して低減さ
せ，該チッ素酸化物の濃度とチッ素酸化物の環境規制値
の差に対した分だけ前記加熱炉の燃焼用空気中の酸素濃
度を高めることを，特徴とする連続加熱炉の酸素富化燃
焼方法である。[Structure of the Invention] (Means for Solving the Problems) The present invention reduces the concentration of nitrogen oxides in the exhaust gas of a continuous heating furnace by reducing the concentration of nitrogen oxides in the exhaust gas of a continuous heating furnace using non-catalytic ammonia removal using a denitration agent consisting of ammonia by-product of the coke oven gas refining process. The oxygen concentration in the combustion air of the heating furnace is increased by the difference between the concentration of nitrogen oxide and the environmental regulation value of nitrogen oxide by applying a denitrification method. This is an oxygen-enriched combustion method using a continuous heating furnace.
すなわち、本発明は一旦高濃度のＮＯｘの発生を許容し
、それが大気に出るまでに大部分を消去してＮＯｘの規
制値に収める．従って、ＮＯｘの発生そのものを抑制し
ようとしている従来のものとは本質的に異なる。この場
合、脱硝コストが問題となるが一貫製鉄所のコークス炉
ガス精製過程で発生する副生アンモニアに着目してこれ
を活用する。しかも炉内に直接添加して反応させる無触
媒アンモニア脱硝法を採用する．このため設備費及び運
転費を大巾に低減することができるものである．なお、
本脱硝法は、脱硝率が反応温度に大きく左右される。そ
こで、炉内各部の温度を検知し、７５０〜１０００℃の
最適範囲にある部分の添加装置のみを開にしてアンモニ
アを添加することで常に安定した脱硝率を得る。That is, the present invention allows the generation of high concentration NOx, and then eliminates most of it before it is released into the atmosphere to bring it within the NOx regulation value. Therefore, it is essentially different from the conventional method which attempts to suppress the generation of NOx itself. In this case, denitrification costs are an issue, but we will focus on and utilize by-product ammonia generated during the coke oven gas refining process in an integrated steelworks. Furthermore, a non-catalytic ammonia denitrification method is adopted in which ammonia is added directly into the furnace and reacted. Therefore, equipment costs and operating costs can be significantly reduced. In addition,
In this denitrification method, the denitrification rate is greatly influenced by the reaction temperature. Therefore, by detecting the temperature of each part in the furnace and adding ammonia by opening only the adding device in the part within the optimum range of 750 to 1000°C, a stable denitrification rate can always be obtained.
また、燃焼量が急激に変動し、かつガス成分，燃焼用空
気の酸素濃度，更には空気比も変動しうる加熱炉におい
てこれらの影響を受け変動するＮＯｘの濃度に対して、
常に過不足のないアンモニアを添加するためにこれら
の値に連動して、アンモニアの添加量を制御している。In addition, in a heating furnace where the combustion amount fluctuates rapidly and the gas composition, oxygen concentration of the combustion air, and even air ratio can fluctuate, the concentration of NOx fluctuates under the influence of these factors.
In order to always add just the right amount of ammonia, the amount of ammonia added is controlled in conjunction with these values.
なお，炉中で発生しているＮＯｘ濃度の推定に当っては
、ガス或分，燃焼空気酸素濃度空気比，空気予熱温度等
から理論火炎温度を計算し、これと炉尻の酸素濃度（＝
余剰酸素）とで現実のＮｏＸｊｌ１度について回帰式を
作りこれを使用している。When estimating the NOx concentration generated in the furnace, the theoretical flame temperature is calculated from the gas fraction, combustion air oxygen concentration/air ratio, air preheating temperature, etc., and this is combined with the oxygen concentration at the bottom of the furnace (=
A regression equation was created for the actual NoXjl 1 degree using (excess oxygen) and used.
（作用） 本発明方法によれば、次の作用を奏する。(effect) According to the method of the present invention, the following effects are achieved.
■ 酸素富化により、増発生したＮＯｘを無触媒アンモ
ニア脱硝法の作用により１７３〜１／４にまで減少せし
め、煙突から排出される時点での濃度を環境規制値以下
に抑えることができる。その結果，同一規制値下で富化
しうる酸素濃度の限界は大幅に上昇し、これに伴い、酸
素富化の燃料節減効果も大となる。このとき，酸素供給
系の容量も増し、設備比も高くなるが、富化限界の上昇
はそれ以上に投資の採算性を良くする．
■ 無触媒アンモニア脱硝法は、マクロ的には次式のよ
うに表われ、有害なＮＯ （一般にＮＯｘの９０％はＮ
Ｏである）は無害なＮ２と１１２０になる．実際には，
多くの素反応の集まりであり、各反応は，温度依存性が
大きい．
従って炉内の煙道，Ｍ．突等の各部の温度を検知し，最
適温度範囲にある添加装置からアンモニアを添加するこ
とで有効に作用させることができる。(2) Due to oxygen enrichment, the increased NOx generated can be reduced to 173 to 1/4 by the action of non-catalytic ammonia denitrification, and the concentration at the time of exhaust from the chimney can be suppressed to below the environmental regulation value. As a result, the limit of oxygen concentration that can be enriched under the same regulation value has increased significantly, and the fuel saving effect of oxygen enrichment has also increased accordingly. At this time, the capacity of the oxygen supply system increases and the equipment ratio increases, but the increase in the enrichment limit makes the investment more profitable. ■ The non-catalytic ammonia denitrification method is macroscopically expressed as the following equation, and harmful NO (generally 90% of NOx is N
O) becomes harmless N2 and 1120. in fact,
It is a collection of many elementary reactions, and each reaction has a strong temperature dependence. Therefore, the flue in the furnace, M. It can be made to work effectively by detecting the temperature of each part of the tube, etc., and adding ammonia from a dosing device that is within the optimum temperature range.
■ 現実の操業では燃料流量は刻々変化しガス或分，燃
焼空気酸素濃度，空気比等も変動し得る。ＮＯｘの発生
量はこれらの関数であり、これらの変動により大きく動
く．
脱硝反応に必要とするアンモニアは、ＮＯＸとモル比で
１：１が原則である。ＮＨ， ／ＮＯｘが０．８を下ま
わると脱硝効率が低下し、Ｎｌｌ３／ＮＯｘが２を超え
ると未反応のアンモニアが煙突から外へ漏出する。■ In actual operation, the fuel flow rate changes from moment to moment, and the gas content, combustion air oxygen concentration, air ratio, etc. can also fluctuate. The amount of NOx generated is a function of these factors, and changes greatly depending on these fluctuations. In principle, the molar ratio of ammonia and NOx required for the denitrification reaction is 1:1. When NH, /NOx is less than 0.8, the denitrification efficiency decreases, and when Nll3 /NOx exceeds 2, unreacted ammonia leaks out from the chimney.
しかし、炉中で発生しているＮＯｘの濃度と排ガスの量
とを推定計算し，モル比でほぼ１：１となるような量の
アンモニアを常に添加することで、このような問題を回
避することができる。However, such problems can be avoided by estimating the concentration of NOx generated in the furnace and the amount of exhaust gas, and constantly adding ammonia in an amount that makes the molar ratio approximately 1:1. be able to.
（実施例）
以下、本発明の実施例について図面を参照して説明する
．
第１図は、予熱帯が非燃焼の場合の連続加熱炉の構成を
示す説明図である。この連続加熱炉３０の場合，均熱帯
及び加熱帯の空気ブロアーと混合燃料ガス間の配管部分
に、酸素の流量を調整する流量調整弁１，混合後の酸素
濃度を検出する検出器２及び酸素濃度を一定値に制御す
るための制御盤３が般けられている。これらの流量調整
弁等１，２，３により酸素濃度供給系が構或されている
。(Example) Examples of the present invention will be described below with reference to the drawings. FIG. 1 is an explanatory diagram showing the configuration of a continuous heating furnace when the preheating zone is non-combustion. In the case of this continuous heating furnace 30, a flow control valve 1 for adjusting the flow rate of oxygen, a detector 2 for detecting the oxygen concentration after mixing, and an oxygen A control panel 3 for controlling the concentration to a constant value is commonly used. These flow rate regulating valves 1, 2, 3 constitute an oxygen concentration supply system.
また，予熱帯の部分には、添加ポイント切換弁６，６，
６，アンモニア溶液供給配管，可変吐出ポンプ５を順次
介してサービス゜タンク４が接続されている。可変吐出
ボンプ５には，アンモニア流量制御盤９が取付けられて
いる。予熱帯のアンモニア溶液供給配管の部分には，ノ
ズル８，８．８が取付けられている．ノズル８の近傍に
は、温度計４．７．７が設けられている。これらの添加
ポイント切換弁等６，６，６，７．７．７，８，８，８
，９により，アンモニア添加系が構成されている。なお
，夫々の添加ポイント切換弁６，６．６は、添加ポイン
ト制御盤に接続されている。In addition, in the preheating zone, addition point switching valves 6, 6,
6, a service tank 4 is connected via an ammonia solution supply pipe and a variable discharge pump 5 in this order. An ammonia flow control panel 9 is attached to the variable discharge pump 5. Nozzles 8 and 8.8 are attached to the ammonia solution supply piping in the preheating zone. A thermometer 4.7.7 is provided near the nozzle 8. These addition point switching valves, etc. 6, 6, 6, 7. 7. 7, 8, 8, 8
, 9 constitute an ammonia addition system. Note that each addition point switching valve 6, 6.6 is connected to an addition point control panel.
第ｌ図に示した実炉の予熱帯における三箇所の地点■，
■，◎からコークス炉ガス精製過程で得られた副生アン
モニアを、所定の流量で供給した。Three points in the preheating zone of the actual reactor shown in Figure 1■,
The by-product ammonia obtained from the coke oven gas purification process from ■ and ◎ was supplied at a predetermined flow rate.
この場合の脱硝率とアンモニア添加地点の温度の関係を
調べたところ、第３図に示す通りであった。The relationship between the denitrification rate and the temperature at the ammonia addition point in this case was investigated, and the results were as shown in FIG.
第３図から明らかなように、例えば■地点でのアンモニ
アの添加によって、６５〜７５％の脱硝率が？られるこ
とが分る。換言すれば、排出されるＮＯｘは、１７３〜
１／４に減少することが分る。As is clear from Figure 3, for example, by adding ammonia at point ■, a denitrification rate of 65 to 75% can be achieved. I know that it will happen. In other words, the NOx emitted is 173~
It can be seen that it decreases to 1/4.
このことから、脱硝しない場合、第４図に示す平均ＮＯ
ｘ値と燃焼空気中の酸素濃度の関係から明らかなように
、２３．７％で規制値に達し，これが富化限界であった
ものを、十分な余裕を見込んでも、２７％０２の酸素富
化燃焼が可能となった。From this, if no denitrification is performed, the average NO
As is clear from the relationship between the x value and the oxygen concentration in the combustion air, the regulation value was reached at 23.7%, which was the enrichment limit. Chemical combustion became possible.
第５図は，上述と同じ実炉による２７％０２下でのＮＯ
ｘ濃度と加熱帯の混合燃料ガスの流量の関係を示してい
る。第５図から明らかなように，長時間の２７％０■の
操業でも規制値を大幅に下まわる結果となっている。２
３．７％と２７％（余裕のとり方によっては２９％まで
可能）の差が本発明の効果である。Figure 5 shows NO under 27%02 using the same actual reactor as above.
It shows the relationship between the x concentration and the flow rate of the mixed fuel gas in the heating zone. As is clear from Figure 5, even with long-term operation at 27% 0■, the results are significantly below the regulation value. 2
The difference between 3.7% and 27% (up to 29% is possible depending on how you take the margin) is the effect of the present invention.
なお、コークス炉ガス精製過程の副生アンモニアは、一
貫製鉄所に於では分解処理に費用のかかる一種の産業廃
棄物であり、これは全くコストのかからないアンモニア
源である。これを活性して、実炉では２流体ノズルでＭ
ａｘ ３ Ｑ ／ｗｉｎ （ ８％の水溶液）の割合で
添加した結果、第３図及び第５図の成果が得られたもの
である。この場合．アンモニアは，ごく微量の添加量で
あり配管，ポンプ等もごく小容量であって！２備費，運
転費共に非常に安価なものであった。Note that ammonia, a by-product of the coke oven gas refining process, is a type of industrial waste that is expensive to decompose in integrated steelworks, but it is a completely cost-free source of ammonia. By activating this, M
As a result of adding at a ratio of ax 3 Q /win (8% aqueous solution), the results shown in FIGS. 3 and 5 were obtained. in this case. The amount of ammonia added is extremely small, and the capacity of the piping, pumps, etc. is also extremely small! 2. Both the equipment and operating costs were extremely low.
また、第３図に示す如く，アンモニアの添加場所の温度
に，脱硝率は大きく左右される。これによって、加熱炉
３０の操業（炉温，燃焼ｉｔ）は、大きく変動するため
、いつも同じポイントで添加していたのでは、安定した
高い脱硝率は得られない。Further, as shown in FIG. 3, the denitrification rate is greatly influenced by the temperature at the place where ammonia is added. As a result, the operation (furnace temperature, combustion IT) of the heating furnace 30 varies greatly, so if it is always added at the same point, a stable and high denitrification rate cannot be obtained.
しかし同図に示すように数ポイント，添加点を設け、各
ポイントの温度を検知しながら適宜、添加点を選択する
ことで高い脱硝率が得られることが分った．
ここで、供給する酸素は純酸素あるいは低純度の酸素の
いずれでも良い．アンモニアも，コークス炉ガス精製過
程の副生物のアンモニア水溶液，同じく水分と共に気化
しているアンモニア蒸気のいずれでも良い．
また、実施例では，供給酸素をフィードバックして酸素
供給量を制御しているが、燃焼空気の流量をオリフィス
流量計で検出して，所定の酸素濃度にするために計算上
必要とされる量の酸素を供給する，比例制御であっても
良い。However, as shown in the figure, it was found that a high denitrification rate could be obtained by setting several addition points and selecting the appropriate addition points while detecting the temperature at each point. Here, the oxygen supplied may be either pure oxygen or low-purity oxygen. The ammonia may be either an ammonia aqueous solution that is a byproduct of the coke oven gas refining process, or ammonia vapor that is also vaporized together with water. In addition, in the example, the amount of oxygen supplied is controlled by feeding back the supplied oxygen, but the flow rate of combustion air is detected by an orifice flow meter, and the amount calculated to achieve a predetermined oxygen concentration is calculated. Proportional control may also be used to supply oxygen.
また，添加ポイントの切替は，温度計７，７，７の指示
値が、前述の最適脱硝温度に一番近い値を示しているポ
イントを次々に選択して行う。Further, the addition points are switched by successively selecting the points at which the indicated values of the thermometers 7, 7, 7 are closest to the above-mentioned optimum denitrification temperature.
更に、予熱帯を焚いているような第２図に示す如き加熱
炉３０の場合には、適温範囲は下流に移っているので、
煙道３１にアンモニア３２を添加すれば良い。Furthermore, in the case of the heating furnace 30 shown in FIG. 2, in which the preheating zone is fired, the appropriate temperature range has shifted downstream, so
Ammonia 32 may be added to the flue 31.
［発明の効果］
以上説明した如く，本発明によれば、次の効果を有する
．
■ 副生アンモニアを活用する無触媒アンモニア脱硝法
の適用により、排出されるＮＯｘ濃度は発生時のそれの
１７３〜１／４に低減することができる。[Effects of the Invention] As explained above, the present invention has the following effects. (2) By applying a non-catalytic ammonia denitrification method that utilizes by-product ammonia, the concentration of NOx discharged can be reduced to 173 to 1/4 of that at the time of generation.
その結果同一環境規制値下で富化しつる（燃焼空気の）
酸素濃度の限界を大幅に高くして、それに伴い酸素富化
の効果を大きくすることができる。As a result, the enrichment of vines (of combustion air) under the same environmental regulation values
The oxygen concentration limit can be significantly increased and the oxygen enrichment effect can be increased accordingly.
■ 酸素富化の効果を大きくすると共に、還元剤にコス
トのかからない副生アンモニアを利用するので、酸素富
化の設備投資額を低減させることができる。- In addition to increasing the effect of oxygen enrichment, the cost-free by-product ammonia is used as a reducing agent, so the capital investment for oxygen enrichment can be reduced.
第１図は本発明の実施例にて使用する加熱炉の説明図、
第２図は本発明の他の実施例にて使用する加熱炉の説明
図、第３図はアンモニア添加地点の温度と脱硝率の関係
を示す特性図、第４図は平均ＮＯｘ値と燃焼空気中の酸
素濃度の関係を示す特性図、第５図はＮＯＸ濃度と加熱
帯の混合燃料ガスの流量の関係を示す特性図である。
１・・・流量調整弁、２・・・酸素濃度検出器、３・・
・酸素濃度制御盤、４・・・サービスタンク，５・・・
可変吐出ポンプ、６，６．６・・・添加ポイント切換弁
，７・・・温度計、８・・・ノズル、９・・・アンモニ
ア流量制御盤。
（１）ｌ）ｍ）FIG. 1 is an explanatory diagram of a heating furnace used in an embodiment of the present invention,
Figure 2 is an explanatory diagram of a heating furnace used in another embodiment of the present invention, Figure 3 is a characteristic diagram showing the relationship between the temperature at the ammonia addition point and the denitrification rate, and Figure 4 is an illustration of the average NOx value and combustion air. FIG. 5 is a characteristic diagram showing the relationship between the NOx concentration and the flow rate of the mixed fuel gas in the heating zone. 1...Flow rate adjustment valve, 2...Oxygen concentration detector, 3...
・Oxygen concentration control panel, 4...Service tank, 5...
Variable discharge pump, 6, 6.6... Addition point switching valve, 7... Thermometer, 8... Nozzle, 9... Ammonia flow rate control panel. (1)l)m)
Claims (3)
コークス炉ガス精製工程の副生アンモニアからなる脱硝
剤による無触媒アンモニア脱硝法を適用して低減させ、
該チッ素酸化物の濃度とチッ素酸化物の環境規制値の差
に対した分だけ前記加熱炉の燃焼用空気中の酸素濃度を
高めることを、特徴とする連続加熱炉の酸素富化燃焼方
法。(1) The concentration of nitrogen oxide in the exhaust gas of a continuous heating furnace is
Applying a non-catalytic ammonia denitrification method using a denitration agent made from ammonia by-product of the coke oven gas purification process,
Oxygen-enriched combustion in a continuous heating furnace, characterized in that the oxygen concentration in the combustion air of the heating furnace is increased by the difference between the concentration of the nitrogen oxide and the environmental regulation value of the nitrogen oxide. Method.
が、７５０〜１０００℃である請求項第１項記載の連続
加熱炉の酸素富化燃焼方法。(2) The oxygen-enriched combustion method in a continuous heating furnace according to claim 1, wherein the atmospheric temperature in the heating furnace to which the by-product ammonia is added is 750 to 1000°C.
度と燃料流量及び空気比に対応した値であり、かつ、チ
ッ素酸化物の上限濃度の値に対応したものである請求項
第１項記載の連続加熱炉の酸素富化燃焼方法。(3) The amount of by-product ammonia added is a value that corresponds to the oxygen concentration of the combustion air, the fuel flow rate, and the air ratio, and also corresponds to the value of the upper limit concentration of nitrogen oxides. The method for oxygen-enriched combustion in a continuous heating furnace according to item 1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1160132A JPH0324225A (en) | 1989-06-22 | 1989-06-22 | Oxygen enriching combustion method for continuous heating furnace |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1160132A JPH0324225A (en) | 1989-06-22 | 1989-06-22 | Oxygen enriching combustion method for continuous heating furnace |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH0324225A true JPH0324225A (en) | 1991-02-01 |
Family
ID=15708564
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1160132A Pending JPH0324225A (en) | 1989-06-22 | 1989-06-22 | Oxygen enriching combustion method for continuous heating furnace |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0324225A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012097312A (en) * | 2010-11-01 | 2012-05-24 | Jfe Steel Corp | Fire extinguishing method of continuous heating furnace |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5023664A (en) * | 1973-06-30 | 1975-03-13 | ||
| JPS5035908A (en) * | 1973-08-02 | 1975-04-04 | ||
| JPS5846338A (en) * | 1981-09-12 | 1983-03-17 | Canon Inc | Illuminating device for copying machine or the like |
| JPS63109118A (en) * | 1986-10-27 | 1988-05-13 | Sumitomo Metal Ind Ltd | Method for operating heating furnace |
-
1989
- 1989-06-22 JP JP1160132A patent/JPH0324225A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5023664A (en) * | 1973-06-30 | 1975-03-13 | ||
| JPS5035908A (en) * | 1973-08-02 | 1975-04-04 | ||
| JPS5846338A (en) * | 1981-09-12 | 1983-03-17 | Canon Inc | Illuminating device for copying machine or the like |
| JPS63109118A (en) * | 1986-10-27 | 1988-05-13 | Sumitomo Metal Ind Ltd | Method for operating heating furnace |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012097312A (en) * | 2010-11-01 | 2012-05-24 | Jfe Steel Corp | Fire extinguishing method of continuous heating furnace |
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