JPS6249521B2 - - Google Patents
Info
- Publication number
- JPS6249521B2 JPS6249521B2 JP54165709A JP16570979A JPS6249521B2 JP S6249521 B2 JPS6249521 B2 JP S6249521B2 JP 54165709 A JP54165709 A JP 54165709A JP 16570979 A JP16570979 A JP 16570979A JP S6249521 B2 JPS6249521 B2 JP S6249521B2
- Authority
- JP
- Japan
- Prior art keywords
- burner
- combustion
- nox
- air
- air ratio
- 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.)
- Expired
Links
- 239000007789 gas Substances 0.000 claims description 15
- 238000002485 combustion reaction Methods 0.000 claims description 14
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 13
- 239000001301 oxygen Substances 0.000 claims description 13
- 229910052760 oxygen Inorganic materials 0.000 claims description 13
- 239000000446 fuel Substances 0.000 claims description 8
- 238000009841 combustion method Methods 0.000 claims description 4
- 239000000203 mixture Substances 0.000 claims description 2
- 239000000567 combustion gas Substances 0.000 claims 3
- 238000000034 method Methods 0.000 description 9
- 239000004071 soot Substances 0.000 description 9
- 239000000428 dust Substances 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 5
- 230000007423 decrease Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 3
- 238000002474 experimental method Methods 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 239000000809 air pollutant Substances 0.000 description 1
- 231100001243 air pollutant Toxicity 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Description
【発明の詳細な説明】
この発明は燃焼装置から排出される排ガス中の
未燃分を増加させることなく窒素酸化物（以下
「NOx」と略称する）を低減する燃焼方法に関す
る。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion method for reducing nitrogen oxides (hereinafter abbreviated as "NOx") without increasing unburned components in exhaust gas discharged from a combustion device.
大気汚染物質の一つであるNOxを低減する方
法は従来より各種提案されているが、NOxを低
減すると煤塵等の未燃分が増加し、反対に未燃分
を減少させるとNOxが増加するという傾向があ
るため、これらNOxおよび未燃分を同時に減少
させることはきめわて困難であつた、このうち、
未燃分の増加は主として低酸素燃焼に起因するも
のでありエネルギの効率的利用の点からも好まし
いものではないので、未燃分の発生は極力押え、
これにより生成されたNOxは脱硝装置を設置す
ることによつて処理して来た。このため燃焼装置
は大型、複数化し、運転経費も多額にのぼつてい
る。 Various methods have been proposed to reduce NOx, which is one of the air pollutants, but reducing NOx increases unburned substances such as soot and dust, and conversely, reducing unburned substances increases NOx. Because of this tendency, it has been extremely difficult to simultaneously reduce these NOx and unburned substances.
The increase in unburned matter is mainly due to low oxygen combustion and is not desirable from the point of view of efficient energy use.
The NOx generated by this has been treated by installing a denitrification device. For this reason, combustion devices have become large and multiple, and operating costs have increased significantly.
この発明の目的は上述した従来技術の欠点をな
くし、未燃分の生成量を抑制しながらNOxの生
成量を減少させることができる燃焼方法を提供す
ることにある。 An object of the present invention is to provide a combustion method capable of eliminating the drawbacks of the prior art described above and reducing the amount of NOx produced while suppressing the amount of unburned matter produced.
要するにこの発明は主バーナの近傍に、空気比
をきわめて小さくとり、かつ主バーナよりも容量
の小さい還元バーナを配置してNOxの還元を行
ない、さらに発生した未燃分は炉内に再導入され
た排ガスもしくは他の不活性ガス中に含有する酸
素により再燃焼させる方法である。 In short, this invention reduces NOx by arranging a reduction burner with an extremely low air ratio and a smaller capacity than the main burner near the main burner, and the unburned content generated is reintroduced into the furnace. This method involves re-burning the fuel using oxygen contained in the exhaust gas or other inert gas.
以下この発明の実施例を説明する。 Examples of the present invention will be described below.
第１図はこの発明に係る方法を実施するための
燃焼装置（ボイラ）を示す。この燃焼装置におい
て、火炉５に対して主燃焼域を形成する複数基
（図示の場合は対向する炉壁に各々２基づつ、合
計８基）の主バーナ（第１のバーナ）１を配置
し、この主バーナ１の近傍には還元性燃焼域を形
成する還元バーナ（第２のバーナ）２が各々配置
されている。この第１のバーナと第２のバーナと
でバーナの組を形成し、ボイラ水壁に複数組配置
する。この場合還元バーナ２は主バーナ１よりも
容量を小さくしておき、さらに両バーナ共に空気
比を１以下としておく。ここで空気比とは各バー
ナに対して供給された燃料の理論空気量に対する
現実に供給された空気量の比である。このうち、
主バーナ１の空気比は約0.8とし、還元バーナ２
の空気比はこれよりも低く、好適には約0.45〜
0.6としておく。以上の空気比の下で燃料Ｆを燃
焼させることにより各バーナ１および２の近傍に
は還元性雰囲気が形成され、NOを中心とする
NOxを無害なN2に還元する。次に二次空気ポー
ト４からは炉内で発生した排ガスＧと燃焼用空気
Ａとを混合した混合気体が供給され、前記還元性
雰囲気下で発生した未燃分を燃焼させる。この
際、供給される混合気体中の酸素濃度は未燃分の
燃焼捉進およびNOxの生成増加抑制の観点から
決定され、後記する実験結果からも明らかなよう
に、10％以下、好適には５％以下とする。以上の
過程において含有する未燃分の大半を燃焼させた
排ガスＧは火炉５を上昇し、火炉上部に設置した
アフタバーナ３において残留する未燃分の殆んど
を燃焼させた後、炉外に排出される。アフタバー
ナ３は未燃分燃焼を可能とするため、空気比をき
わめて大きく、例えば空気比５〜７程度とし、僅
かなガス滞留時間で大きな未燃分燃焼率を得るよ
うにしておく。但し、このアフタバーナ３の容量
は前記バーナ１および２に比較して小さくしてあ
るので供給される酸素の絶対量はさして多くな
く、NOx生成量の増加はきわめて僅かに押える
ことができる。 FIG. 1 shows a combustion apparatus (boiler) for carrying out the method according to the invention. In this combustion apparatus, a plurality of main burners (first burners) 1 are arranged in a furnace 5 to form a main combustion zone (in the case shown, two burners each on opposing furnace walls, eight in total). In the vicinity of the main burner 1, reducing burners (second burners) 2 forming reducing combustion zones are arranged. The first burner and the second burner form a burner set, and a plurality of burner sets are arranged on the boiler water wall. In this case, the capacity of the reduction burner 2 is set smaller than that of the main burner 1, and the air ratio of both burners is set to 1 or less. Here, the air ratio is the ratio of the actually supplied air amount to the theoretical air amount of fuel supplied to each burner. this house,
The air ratio of main burner 1 is approximately 0.8, and the reduction burner 2
The air ratio is lower than this, preferably around 0.45~
Set it to 0.6. By burning fuel F under the above air ratio, a reducing atmosphere is formed near each burner 1 and 2, and NO is mainly
Reduces NOx to harmless N2 . Next, from the secondary air port 4, a mixed gas consisting of the exhaust gas G generated in the furnace and the combustion air A is supplied, and the unburned matter generated in the reducing atmosphere is combusted. At this time, the oxygen concentration in the supplied gas mixture is determined from the viewpoint of trapping the unburned matter and suppressing the increase in NOx production, and as is clear from the experimental results described later, it is preferably 10% or less. 5% or less. The exhaust gas G, in which most of the unburned matter contained in the above process has been burned, ascends through the furnace 5, burns most of the remaining unburned matter in the afterburner 3 installed at the top of the furnace, and then flows out of the furnace. be discharged. Since the afterburner 3 is capable of burning unburned matter, the air ratio is set to be extremely large, for example, about 5 to 7, so that a large unburned matter combustion rate can be obtained with a short gas residence time. However, since the capacity of the afterburner 3 is smaller than that of the burners 1 and 2, the absolute amount of oxygen supplied is not very large, and the increase in the amount of NOx produced can be suppressed to a very small amount.
次に発明者等はこの発明に係る方法に基づき燃
焼実験を行つたが、この実験結果に基づきこの発
明に係る方法をさらに具体的に説明する。なお実
験に用いた燃焼炉は２ｍ、奥行き２ｍ、高さ2.5
ｍの箱型炉で、耐火材で内張りし、外装部は水冷
壁としたものを用いたが、バーナおよび二次空気
ポートの配置状態は第１図に示したものと同一で
あるため、便宜的に第１図を用いて説明する。こ
の実験においては主バーナ１の空気比約0.8、還
元バーナ２の空気比を約0.5、アフタバーナ３の
空気比を約７とした。また火炉５に設けた全バー
ナに対する燃料供給量を100％とした場合、各バ
ーナに対する燃料配分を次の如く行つた。なおカ
ツコ内は火炉５に対するバーナの設置本数であ
る。 Next, the inventors conducted a combustion experiment based on the method according to the present invention, and the method according to the present invention will be explained in more detail based on the experimental results. The combustion furnace used in the experiment was 2m long, 2m deep, and 2.5m high.
We used a box-shaped furnace of 1.5 m, lined with refractory material, and a water-cooled wall on the exterior, but the arrangement of the burners and secondary air ports is the same as that shown in Figure 1, so it is convenient to use This will be explained with reference to FIG. In this experiment, the air ratio of the main burner 1 was about 0.8, the air ratio of the reduction burner 2 was about 0.5, and the air ratio of the afterburner 3 was about 7. Further, assuming that the amount of fuel supplied to all the burners provided in the furnace 5 is 100%, the fuel distribution to each burner was performed as follows. Note that the number in the box is the number of burners installed in the furnace 5.
(a) 主バーナ１（８本） ……62％
(b) 還元バーナ２（８本） ……31％
(c) アフタバーナ３（４本） ……７％
また使用した燃料は灯油であり、かつピリジン
を添加することにより燃料中のＮ分濃度が約0.1
％としたものを用いた。(a) Main burner 1 (8 pieces) ...62% (b) Reduction burner 2 (8 pieces) ...31% (c) After burner 3 (4 pieces) ...7% The fuel used was kerosene, And by adding pyridine, the N content in the fuel can be reduced to approximately 0.1.
% was used.
以上のこの条件下で複数のバーナ組の燃焼ガス
流れ方向につきバーナ組間、即ち第１図では上下
のバーナ組間に酸素含有気体を供給する所謂二次
空気ポート４から供給される混合気体中の酸素濃
度を0.1％から19.9％まで変化させ、これによる
NOx，COおよび煤塵の生成量の変化を計測し
た。これら三者の計測はこの発明に基づき二次空
気ポート４から混合気体を導入した場合と、二次
空気ポート４から混合気体を全く導入しない従来
方法との比較において行なわれ、第２図はこの比
較結果を示す。なお、これらの計測位置はすべて
火炉出口である。図中、左側の縦軸は従来方法に
係るNOx排出量（mole／min）対するこの発明に
よるNOx排出量（mole／min）の比を求め、右側
縦軸はCOおよび煤塵について同様の比（計量単
位はmg／ｈ）をとつたものである。つまり、この
図においては各グラフの縦軸の値が1.0以下とな
れば、この発明に係る方法におけるNOx等の生
成量が従来方法よりも少ないことを意味する。同
図において、煤塵（符号イで示す）は酸素濃度が
５％までは急激に減少し、かつCO（符号ロで示
す）は酸素濃度の増加と共に除々に減少する。こ
れに対して符号ハで示すNOxは酸素濃度が約2.5
までは減少し、以後は従来方法より多少増加す
る。以上の線図から明らかな如く、酸素濃度が約
2.5まではNOx生成量、煤塵生成量およびCO生成
量共に減少する。以下NOx生成量は漸増する
が、酸素濃度約５までの間は許容値内であり、か
つ煤塵生成量は大巾に減少する。従つて前記二次
空気ポート４から供給する混合気体中の酸素濃度
は約５以下が適当であることが解つた。 Under these conditions, the mixed gas is supplied from the so-called secondary air port 4 that supplies oxygen-containing gas between the burner sets, that is, between the upper and lower burner sets in FIG. By varying the oxygen concentration from 0.1% to 19.9%,
Changes in the amount of NOx, CO, and soot produced were measured. These three measurements were conducted based on the present invention, comparing the case where a mixed gas is introduced from the secondary air port 4 and the conventional method in which no mixed gas is introduced from the secondary air port 4. Comparison results are shown. Note that all of these measurement positions are at the furnace exit. In the figure, the vertical axis on the left is the ratio of NOx emissions (mole/min) according to the present invention to the NOx emissions (mole/min) according to the conventional method, and the vertical axis on the right is the same ratio (measured) for CO and soot. The unit is mg/h). In other words, in this figure, if the value on the vertical axis of each graph is 1.0 or less, it means that the amount of NOx etc. generated in the method according to the present invention is smaller than in the conventional method. In the figure, soot and dust (indicated by the symbol A) rapidly decreases when the oxygen concentration reaches 5%, and CO (indicated by the symbol B) gradually decreases as the oxygen concentration increases. On the other hand, NOx shown with the symbol C has an oxygen concentration of approximately 2.5.
It decreases until then, and after that it increases somewhat compared to the conventional method. As is clear from the diagram above, the oxygen concentration is approximately
Up to 2.5, the amount of NOx, soot and dust, and CO all decrease. Thereafter, the amount of NOx produced gradually increases, but until the oxygen concentration reaches about 5, it remains within the permissible value, and the amount of soot and dust produced significantly decreases. Therefore, it has been found that the oxygen concentration in the mixed gas supplied from the secondary air port 4 is suitably about 5 or less.
この発明によればNOxの生成量と煤塵等の未
燃分生成量を同時に減少させることができるので
特別な脱硝装置、煤塵処理装置を設置する必要が
なく経済的である。 According to this invention, the amount of NOx produced and the amount of unburned matter such as soot and dust produced can be reduced at the same time, so there is no need to install a special denitrification device or soot and dust treatment device, which is economical.
第１図はこの発明に係る方法を実施するボイラ
の系統図、第２図はこの発明に係る方法と従来方
法とにおけるNOx、煤塵およびCOの排出量を比
較する線図である。
１…主バーナ、２…還元バーナ、３…アフタバ
ーナ、４…二次空気ポート、５…火炉、Ｇ…排ガ
ス、Ａ…燃焼用空気。
FIG. 1 is a system diagram of a boiler implementing the method according to the present invention, and FIG. 2 is a diagram comparing the emissions of NOx, soot, and CO between the method according to the present invention and the conventional method. 1...Main burner, 2...Reduction burner, 3...After burner, 4...Secondary air port, 5...Furnace, G...Exhaust gas, A...Combustion air.
Claims (1)
ス流れについて後流で燃料を燃焼させる第２のバ
ーナとで、１のバーナ組を形成し、このバーナ組
を複数組有し、しかもこの複数のバーナ組の燃焼
ガスの後流でこの燃焼ガス中に含まれる未燃分を
燃焼させる空気を供給する空気孔を有した燃焼装
置であつて、前記第１のバーナを空気比１以下で
燃焼させ、前記第２のバーナを前記第１のバーナ
の空気比よりも低い空気比で燃焼させる前記複数
のバーナ組の燃焼ガス流れ方向についてのバーナ
組間に酸素含有気体を供給することを特徴とする
NOx・未燃分低減燃焼方法。 ２ 酸素含有気体は空気と燃焼排ガスの混合した
気体であることを特徴とする特許請求の範囲第１
項記載のNOx・未燃分低減燃焼方法。[Claims] 1. A first burner and a second burner that burns fuel in the wake of the combustion gas flow of the first burner form one burner group, and a plurality of burner groups are formed. The combustion device has an air hole for supplying air for burning unburned matter contained in the combustion gas in the downstream of the combustion gas of the plurality of burner groups, is combusted at an air ratio of 1 or less, and the second burner is combusted at an air ratio lower than the air ratio of the first burner. characterized by supplying
Combustion method to reduce NOx and unburned matter. 2. Claim 1, wherein the oxygen-containing gas is a mixture of air and combustion exhaust gas.
Combustion method for reducing NOx and unburned matter described in section.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16570979A JPS5691108A (en) | 1979-12-21 | 1979-12-21 | Combustion method capable of reducing nox and uncombusted substance |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP16570979A JPS5691108A (en) | 1979-12-21 | 1979-12-21 | Combustion method capable of reducing nox and uncombusted substance |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5691108A JPS5691108A (en) | 1981-07-23 |
| JPS6249521B2 true JPS6249521B2 (en) | 1987-10-20 |
Family
ID=15817557
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP16570979A Granted JPS5691108A (en) | 1979-12-21 | 1979-12-21 | Combustion method capable of reducing nox and uncombusted substance |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5691108A (en) |
Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS57403A (en) * | 1980-06-03 | 1982-01-05 | Babcock Hitachi Kk | Reducing method of nitrogen oxides in exhaust gas and its device |
| DE3531571A1 (en) * | 1985-09-04 | 1987-03-05 | Steinmueller Gmbh L & C | METHOD FOR BURNING FUELS WITH A REDUCTION IN NITROGEN OXIDATION AND FIRE FOR CARRYING OUT THE METHOD |
| FR2606490B1 (en) * | 1986-11-07 | 1990-07-13 | Gaz De France | PRE-MIXED BLOW-AIR TYPE GAS BURNER |
| US5158445A (en) * | 1989-05-22 | 1992-10-27 | Institute Of Gas Technology | Ultra-low pollutant emission combustion method and apparatus |
| US5013236A (en) * | 1989-05-22 | 1991-05-07 | Institute Of Gas Technology | Ultra-low pollutant emission combustion process and apparatus |
| US5470224A (en) * | 1993-07-16 | 1995-11-28 | Radian Corporation | Apparatus and method for reducing NOx , CO and hydrocarbon emissions when burning gaseous fuels |
| JP2002115808A (en) * | 2000-10-12 | 2002-04-19 | Asahi Glass Co Ltd | Nitrogen oxide reduction method in combustion gas in combustion furnace |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4961723A (en) * | 1972-05-12 | 1974-06-14 | ||
| JPS5495020A (en) * | 1978-01-11 | 1979-07-27 | Mitsubishi Heavy Ind Ltd | Fuel combustion system for boiler |
-
1979
- 1979-12-21 JP JP16570979A patent/JPS5691108A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4961723A (en) * | 1972-05-12 | 1974-06-14 | ||
| JPS5495020A (en) * | 1978-01-11 | 1979-07-27 | Mitsubishi Heavy Ind Ltd | Fuel combustion system for boiler |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5691108A (en) | 1981-07-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPS5623615A (en) | Burning method for low nox | |
| KR970009487B1 (en) | METHOD FOR REDUCING NOx PRODUCTION DURING AIR - FUEL COMBUSTION PROCESS | |
| JPH0762524B2 (en) | Waste combustion method and equipment | |
| JPS6249521B2 (en) | ||
| Teng et al. | Control of NOx emissions through combustion modifications for reheating furnaces in steel plants | |
| EP0824649B1 (en) | NOx reduction in a circulating fluidized bed | |
| US5934892A (en) | Process and apparatus for emissions reduction using partial oxidation of combustible material | |
| JPH0814505A (en) | Method and apparatus for burning low nox of boiler | |
| JPS60126508A (en) | Finely powdered coal burning device | |
| JP2870675B2 (en) | How to operate the pyrolytic combustion zone | |
| Straitz III et al. | Combat NOx with better burner design | |
| JPS6243084B2 (en) | ||
| JP3217470B2 (en) | Boiler equipment | |
| JPH07301403A (en) | Combustion device of boiler furnace | |
| JPS6021606Y2 (en) | Low NO↓x heat sintering equipment | |
| JPH09126412A (en) | Low nox boiler | |
| EP0554254A1 (en) | AN ADVANCED OVERFIRE AIR SYSTEM FOR NO x CONTROL. | |
| KR840000354B1 (en) | Combustion method for low nox | |
| JP2895061B2 (en) | Combustion method for boiler combustion device | |
| JPH06201105A (en) | Method and device for low-nox combustion | |
| SU1758336A1 (en) | Fuel combustion method | |
| JPS58145810A (en) | Combustion of coal | |
| JPS58102006A (en) | Low nox pulverized coal burner | |
| RU2031311C1 (en) | Method of fuel burning | |
| JPS57207703A (en) | Low nox combustion method with improved boiler efficiency |