JPH059684B2 - - Google Patents
Info
- Publication number
- JPH059684B2 JPH059684B2 JP4705984A JP4705984A JPH059684B2 JP H059684 B2 JPH059684 B2 JP H059684B2 JP 4705984 A JP4705984 A JP 4705984A JP 4705984 A JP4705984 A JP 4705984A JP H059684 B2 JPH059684 B2 JP H059684B2
- Authority
- JP
- Japan
- Prior art keywords
- pulverized coal
- flame
- ignition
- nozzle
- torch
- 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 - Lifetime
Links
- 239000003245 coal Substances 0.000 claims description 93
- 238000010891 electric arc Methods 0.000 claims description 2
- 239000000446 fuel Substances 0.000 description 15
- 238000002485 combustion reaction Methods 0.000 description 7
- 238000010586 diagram Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 239000003381 stabilizer Substances 0.000 description 6
- 239000003208 petroleum Substances 0.000 description 5
- 230000000694 effects Effects 0.000 description 4
- 239000000295 fuel oil Substances 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 230000005855 radiation Effects 0.000 description 3
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 2
- 229910052721 tungsten Inorganic materials 0.000 description 2
- 239000010937 tungsten Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 230000000903 blocking effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003610 charcoal Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000009841 combustion method Methods 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 239000000498 cooling water Substances 0.000 description 1
- 229910052802 copper Inorganic materials 0.000 description 1
- 239000010949 copper Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000011017 operating method Methods 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Description
【発明の詳細な説明】
〔発明の利用分野〕
本発明は微粉炭燃焼装置に係り、特に、補助用
燃料である軽油及び重油を使用せずに、微粉炭を
常温から点火し、安定な微粉炭燃焼火炎を形成す
るためのアーク式点火トーチを内蔵する微粉炭バ
ーナに関する。Detailed Description of the Invention [Field of Application of the Invention] The present invention relates to a pulverized coal combustion device, and in particular, it ignites pulverized coal at room temperature without using light oil or heavy oil as auxiliary fuel, and produces stable pulverized powder. This invention relates to a pulverized coal burner with a built-in arc-type ignition torch for forming a charcoal combustion flame.
従来、微粉炭ボイラには、燃料となる微粉炭の
他に補助燃料として軽油及び重油等の石油系燃料
が用いられている。補助燃料の使用目的は、ボイ
ラのスタートアツプ用と、負荷変動の際に、燃焼
状態を安定させるためとに大別される。前者は、
微粉炭の着火性が常温で悪いこと、従来使用され
る点火トーチは、ガス燃料あるいは石油系燃料な
どの比較的点火しやすい燃料に使用されるスパー
ク式のものが流用されていることなどから、常温
で微粉炭を点火するのは困難であつた。そこで、
ボイラのスタートアツプには燃焼性の良い軽油及
び重油などの石油系燃料が使用され、ボイラ内の
温度が上つた時点で、石油系燃料と微粉炭を切換
え、微粉炭専焼に移行する運転方法が通例であつ
た。これら石油系燃料を使用するため多量の補助
燃料を必要とし、また、補助燃料の貯蔵及び供給
設備費などの経済的に大きな負担がユーザ側に課
せられていた。
Conventionally, in pulverized coal boilers, petroleum-based fuels such as light oil and heavy oil are used as auxiliary fuels in addition to pulverized coal as fuel. The purposes of using auxiliary fuel are broadly divided into boiler startup and stabilizing combustion conditions during load fluctuations. The former is
Pulverized coal has poor ignitability at room temperature, and conventionally used ignition torches are spark-type torches that are used for fuels that are relatively easy to ignite, such as gas fuel or petroleum-based fuel. It was difficult to ignite pulverized coal at room temperature. Therefore,
Petroleum-based fuels such as light oil and heavy oil with good combustibility are used to start up the boiler, and when the temperature inside the boiler rises, the operating method switches between petroleum-based fuel and pulverized coal to switch to pulverized coal-only combustion. It was customary. The use of these petroleum-based fuels requires a large amount of auxiliary fuel, and also imposes a large economic burden on the user, such as the cost of storage and supply equipment for the auxiliary fuel.
そこで、これら補助燃料の低減もしくは補助燃
料を使用しないで、微粉炭の安定な燃焼を行なう
技術が特公昭58−1330号公報で開示されている。
この新しい燃焼方法は第１図に示すように、アー
ク点火トーチ２（プラズマアーク溶接機などに使
用されている。）を用いて、プラズマアークフレ
ーム３を微粉炭バーナ１から噴出する微粉炭／空
気流４に接触させ、高温のフレーム３によつて微
粉炭を着火させる方法である。アーク式点火トー
チ２を用いた微粉炭の点火は従来の問題点を解決
するには有効な方法であると考えられる。しか
し、この技術には単に与えられる点火トーチ側か
らの点火エネルギ（及びエンタルピ）と微粉炭／
空気流の各々の濃度で定義される着火パラメータ
の指定された領域内で着火することが記載されて
いるが、発明者らは実験の結果微粉炭／空気流の
流速にアーク式点火トーチ２からのプラズマアー
クフレーム３を接触した場合、単に微粉炭／空気
流４の各々の濃度及びプラズマトーチ側の点火エ
ネルギが前記公報に記載される着火パラメータの
領域であつても、安定な着火ができなかつた。こ
の原因として、プラズマアークフレームの貫通力
が微粉炭／空気流の流速によつて影響されること
に起因する。この原因を発明者らの実験結果の一
例である第２図に基づいて詳細に説明する。第２
図ａはプラズマアークフレーム３が微粉炭／空気
流４の流速が大であるために微粉炭／空気流４に
充分接触できず、微粉炭の着火が安定して実施で
きない場合を示す概念図である。第２図ｂは微粉
炭／空気流４の流速が小さく、逆に、プラズマア
ークフレーム３の高温部分を混合流が避けて通過
し、微粉炭の着火が安定に実施できない概念図で
ある。また、先に示した第１図のようにアーク式
点火トータ２を微粉炭バーナ１から離し、微粉
炭／空気流の噴出直後に設置した場合、微粉炭の
供給量及び空気量は操作側で把握できるが、噴出
された後流側では、空気の流れ及びバーナ構造に
よつて微粉炭濃度が一様でなくなり、操作条件だ
けではトーチからのアークフレームの位置する示
所で、前記公報に記載される着火領域内にあるこ
との判断は困難であり、必ずしも、着火領域にあ
るとは限らない。従つて、従来のように、単に、
微粉炭量、空気量及び点火エネルギのみでは着火
領域を限定することはできない。 Therefore, Japanese Patent Publication No. 1330/1983 discloses a technique for stably burning pulverized coal by reducing or not using these auxiliary fuels.
As shown in Fig. 1, this new combustion method uses an arc ignition torch 2 (used in plasma arc welding machines, etc.) to generate a plasma arc flame 3 with pulverized coal/air ejected from a pulverized coal burner 1. In this method, pulverized coal is brought into contact with a stream 4 and ignited by a high-temperature flame 3. Ignition of pulverized coal using the arc type ignition torch 2 is considered to be an effective method for solving the conventional problems. However, this technology simply requires the ignition energy (and enthalpy) from the ignition torch side and the pulverized coal/
Although it is described that ignition occurs within a specified range of ignition parameters defined by the concentration of each air stream, the inventors have experimentally found that the flow rate of the pulverized coal/air stream is different from the arc type ignition torch 2. When a plasma arc flame 3 of Ta. This is due to the fact that the penetration power of the plasma arc flame is influenced by the flow rate of the pulverized coal/air flow. The cause of this will be explained in detail based on FIG. 2, which is an example of the inventors' experimental results. Second
Figure a is a conceptual diagram showing a case in which the plasma arc flame 3 cannot make sufficient contact with the pulverized coal/air flow 4 because the flow velocity of the pulverized coal/air flow 4 is high, and the pulverized coal cannot be ignited stably. be. FIG. 2b is a conceptual diagram in which the flow velocity of the pulverized coal/air flow 4 is low, and conversely, the mixed flow avoids and passes through the high temperature portion of the plasma arc flame 3, making it impossible to stably ignite the pulverized coal. In addition, if the arc type ignition totaler 2 is separated from the pulverized coal burner 1 and installed immediately after the pulverized coal/air flow is ejected as shown in Figure 1 above, the amount of pulverized coal supplied and the amount of air can be controlled by the operator However, on the downstream side of the ejected coal, the concentration of pulverized coal is not uniform due to the air flow and burner structure, and the operating conditions alone indicate that the arc flame from the torch is located at the specific point described in the above publication. It is difficult to determine whether the fuel is within the ignition range, and is not necessarily within the ignition range. Therefore, as before, simply
The ignition region cannot be limited only by the amount of pulverized coal, the amount of air, and the ignition energy.
本発明の目的は、アーク式点火トーチを備えた
微粉炭バーナを提供するにある。
An object of the present invention is to provide a pulverized coal burner equipped with an arc type ignition torch.
本発明の要点は、プラズマアークフレームと微
粉炭／空気流との接触を効率良く実施し、また、
微粉炭／空気流の操作条件で微粉炭の着火領域内
にあることなど、制御面での操作を簡略化し、安
定に微粉炭の着火が実施できるようにアーク式点
火トーチを微粉炭バーナと一体化構造にした点に
ある。
The key points of the invention are to efficiently bring the plasma arc flame into contact with the pulverized coal/air stream, and to
The arc-type ignition torch is integrated with the pulverized coal burner to simplify control operations and ensure stable ignition of pulverized coal, such as being within the pulverized coal ignition range under pulverized coal/air flow operating conditions. The reason lies in the fact that it has a structured structure.
本発明の実施例を第３図ないし第８図を用いて
詳細に説明する。
Embodiments of the present invention will be described in detail with reference to FIGS. 3 to 8.
第３図は本発明の一実施例のアーク式点火トー
チを備えた微粉炭バーナの全体構成図である。ア
ーク式点火トーチ２はバーナが円筒状である場
合、中心部に設置する。その外側には微粉炭／空
気流の噴出ノズル８、さらに、外周側に二次空気
ノズル９及び三次空気ノズル１０が配置される。
二次空気ノズル９及び三次空気ノズル１０には
各々の空気に旋回運動を与えるための旋回器１
１，１２が配置される。本発明の微粉炭バーナ１
に使用されるアーク式点火トーチの詳細構造を第
４図に示す。本発明のバーナでは先端が針状のタ
ングステン製電極１４を−極に使用し、銅製ノズ
ル１５を＋極に構成し、高周波電源１７によつて
両極間に電気アークを発生する。本発明では、プ
ラズマガスとしてアルゴンガス（Ar）２１を使
用し、プラズマアークフレーム３を形成した。プ
ラズマアーク部３′は8000℃以上の高温領域とな
るがアークフレーム３の先端部は8000℃以下であ
る。このプラズマアークフレーム３に微粉炭／空
気流を効果的に接触することが前提条件となる。
また、アーク発生部は高温になるためタングステ
ン製電極１４及びノズル１５は冷却構造体とし、
冷却水２０，２２がノズル内側に流入できるよう
にした。外周部はシールドキヤツプ１６が絶縁筒
１８に支持され、ノズル１５とシールドキヤツプ
間にシールドガス１９が流出できるようにし、通
常は空気をシールドガス１９として使用した。プ
ラズマフレーム３の長さは、プラズマガス２１の
流量及び高周波電源１７からの出力で決定される
プラズマアーク出力によつて左右される。発明者
らの実験結果では、ノズル１５の噴出流速は20℃
換算で、3m／ｓ以上とすることが好ましく、プ
ラズマアーク出力は1.5KW以上であると良好な
プラズマアークフレーム３が形成できることを確
認している。アーク式点火トーチは円筒状の微粉
炭バーナ１では中心部に位置するように説明して
きたが、微粉炭の着火には微粉炭／空気流の噴出
状態と、プラズマアークフレームの接触が最も重
要な因子となる。第５図は本発明の微粉炭バーナ
の微粉炭／空気流ノズル８の先端部の詳細構造を
示す。微粉炭／空気流ノズル先端の保炎器２３
は、微粉炭／空気流の噴出速度によつてトーチ２
の内側及び外側に動き得る構造体とした。微粉炭
の常温での着火は通常の火炉壁からの放射のない
苛酷な条件で行なうため、着火領域は狭くなる。
そこで、常に、着火を安定して行なうために発明
したのが可動型の保炎器２３である。微粉炭／空
気流の噴出速度は逆火防止のため、ある一定の流
速以上に保たれる。これは微粉炭燃焼火炎の伝播
速度より大きな速度で噴出することが必要条件と
なる。一般には、10m／ｓ以上に設定されてい
る。そこで、本発明では噴出速度は10m／ｓ以上
にするように微粉炭／空気流を設定し、且つ、
17m／ｓ以下では保炎器２３の向きがトーチ側の
内側に傾斜するように保炎器２３の重量を調整し
た。このように構成することによつて、微粉炭／
空気流がプラズマアークフレーム３に接触しやす
くなり、微粉炭を安定に着火することができる。
プラズマアークフレーム３を形成している期間
は、微粉炭に点火エネルギが与えられているから
微粉炭は安定して燃焼することができる。微粉炭
の着火によつて微粉炭燃焼火炎の温度が高まるの
で、時間が経過していくほど、微粉炭は火炎面か
らの放射によつて安定して燃焼させることができ
る。このように常温から微粉炭を着火する場合に
は、噴出流速は小さい方が好ましいが、逆火の立
場からは、10m／ｓ以上が好ましく、発明者らは
17m／ｓ以下にすることが常温での着火には有利
であることを見い出した。従つて、常温からの着
火条件は微粉炭の濃度に起因する着火限界の他に
噴出速度も一つの着火に影響する因子の一つであ
る。また、着火する時点では10〜17m／ｓの領域
で微粉炭／空気流を噴出させるが、ノズル構造が
決定されると、単一バーナから供給される微粉炭
量を増加するためには、必然的に一次空気量も増
加し、おのずと噴出速度は増加する。そこで本発
明では約17m／ｓ以上になると保炎器２３の重量
に打ち勝つて噴出時の圧力が高くなり、保炎器２
３を外側に向けるように保炎器２３の重量を決定
した。この外側への保炎器２３の角度θは保炎器
２３の外側に設けられた支持板２４によつて制約
を受け、θが10度以上になるように設置した。こ
のように保炎器２３による保炎効果を得るには、
外向きにし、微粉炭が噴出された直後に微粉炭が
外側に広がる効果と、二次空気が噴出された直後
に保炎器２３によつて二次空気の一部が微粉炭／
空気流に巻き込まれるため、火炎は保炎器２３の
近傍から形成されて微粉炭の燃焼が良好に実施さ
れる。プラズマアークフレーム３の照射時間は火
炎温度が高まり、火炉壁など雰囲気温度が高まつ
て、放射により微粉炭の火炎が継続できる条件に
なつた時点を基準に決定される。 FIG. 3 is an overall configuration diagram of a pulverized coal burner equipped with an arc type ignition torch according to an embodiment of the present invention. If the burner is cylindrical, the arc type ignition torch 2 is installed in the center. A pulverized coal/air flow jetting nozzle 8 is arranged on the outside thereof, and furthermore, a secondary air nozzle 9 and a tertiary air nozzle 10 are arranged on the outer peripheral side.
The secondary air nozzle 9 and the tertiary air nozzle 10 each have a swirler 1 for giving swirling motion to the air.
1 and 12 are arranged. Pulverized coal burner 1 of the present invention
Figure 4 shows the detailed structure of the arc-type ignition torch used for this purpose. In the burner of the present invention, a tungsten electrode 14 with a needle-like tip is used as a negative pole, a copper nozzle 15 is configured as a positive pole, and a high frequency power source 17 generates an electric arc between the two poles. In the present invention, the plasma arc flame 3 was formed using argon gas (Ar) 21 as the plasma gas. The plasma arc portion 3' is a high temperature region of 8000°C or higher, but the temperature at the tip of the arc frame 3 is 8000°C or lower. Effective contact of the pulverized coal/air stream with this plasma arc flame 3 is a prerequisite.
In addition, since the arc generating part becomes high temperature, the tungsten electrode 14 and the nozzle 15 are made into a cooling structure.
Cooling water 20, 22 is allowed to flow into the inside of the nozzle. At the outer periphery, a shield cap 16 is supported by an insulating tube 18 so that a shield gas 19 can flow out between the nozzle 15 and the shield cap, and air is normally used as the shield gas 19. The length of the plasma flame 3 depends on the plasma arc output determined by the flow rate of the plasma gas 21 and the output from the high frequency power source 17. According to the inventors' experimental results, the jet flow velocity of the nozzle 15 was 20°C.
In terms of conversion, it is preferable to set it to 3 m/s or more, and it has been confirmed that a good plasma arc flame 3 can be formed when the plasma arc output is 1.5 KW or more. We have explained that the arc type ignition torch is located at the center of the cylindrical pulverized coal burner 1, but the most important factors for igniting the pulverized coal are the jetting state of the pulverized coal/air flow and the contact with the plasma arc flame. Become a factor. FIG. 5 shows the detailed structure of the tip of the pulverized coal/air flow nozzle 8 of the pulverized coal burner of the present invention. Pulverized coal/flame stabilizer 23 at the tip of the air flow nozzle
torch 2 depending on the ejection speed of the pulverized coal/air stream.
The structure is designed to be able to move inward and outward. Since pulverized coal is ignited at room temperature under harsh conditions with no radiation from the furnace walls, the ignition area is narrow.
Therefore, a movable flame holder 23 was invented to ensure stable ignition at all times. The jetting speed of the pulverized coal/air stream is kept above a certain flow rate to prevent backfire. This requires that the pulverized coal be ejected at a speed greater than the propagation speed of the pulverized coal combustion flame. Generally, it is set to 10 m/s or more. Therefore, in the present invention, the pulverized coal/air flow is set so that the jetting speed is 10 m/s or more, and
At speeds below 17 m/s, the weight of the flame holder 23 was adjusted so that the direction of the flame holder 23 was inclined inward toward the torch side. With this configuration, pulverized coal/
The air flow comes into contact with the plasma arc flame 3 more easily, and the pulverized coal can be ignited stably.
During the period when the plasma arc flame 3 is being formed, ignition energy is given to the pulverized coal, so that the pulverized coal can be stably combusted. Ignition of the pulverized coal increases the temperature of the pulverized coal combustion flame, so as time passes, the pulverized coal can be more stably combusted by radiation from the flame surface. In this way, when igniting pulverized coal from room temperature, it is preferable that the ejection flow velocity is small, but from the standpoint of backfire, it is preferable that it is 10 m/s or more, and the inventors
It has been found that setting the speed to 17 m/s or less is advantageous for ignition at room temperature. Therefore, regarding the ignition conditions from room temperature, in addition to the ignition limit due to the concentration of pulverized coal, the jetting speed is one of the factors that influences ignition. In addition, at the time of ignition, the pulverized coal/air flow is ejected in the region of 10 to 17 m/s, but once the nozzle structure is decided, it is necessary to increase the amount of pulverized coal supplied from a single burner. As a result, the amount of primary air also increases, and the ejection speed naturally increases. Therefore, in the present invention, when the speed exceeds about 17 m/s, the pressure at the time of ejection increases to overcome the weight of the flame holder 23, and the flame holder 23
The weight of the flame holder 23 was determined so that the flame holder 23 was oriented outward. The angle θ of the flame stabilizer 23 toward the outside was restricted by the support plate 24 provided on the outside of the flame stabilizer 23, and the flame stabilizer 23 was installed so that θ was 10 degrees or more. In order to obtain the flame holding effect by the flame holding device 23 in this way,
The effect is that the pulverized coal spreads outward immediately after the pulverized coal is blown out, and the flame stabilizer 23 causes a part of the secondary air to spread out from the pulverized coal/
Since the flame is caught in the air flow, the flame is formed from the vicinity of the flame stabilizer 23, and the combustion of the pulverized coal is carried out satisfactorily. The irradiation time of the plasma arc flame 3 is determined based on the point in time when the flame temperature increases, the temperature of the atmosphere such as the furnace wall increases, and conditions are reached where the flame of the pulverized coal can continue due to radiation.
次に、第６図、第７図を用いて微粉炭濃度とプ
ラズマアーク出力によつて決定される微粉炭の着
火限界と、着火後、プラズマアークフレームを停
止し、火炎を継続して形成するための条件を実験
結果に基づいて説明する。第６図、第７図に示す
実験結果は、微粉炭として国内の太平洋炭を用
い、粒径が200メツシユ（74μm）以下80％になる
ように調整したものを使用した。石炭中の揮発分
は約38％、固定炭素分は同様に約38〜39％、灰分
は14％程度である。微粉炭／空気流の噴出速度は
15m／ｓ一定、微粉炭濃度は微粉炭供給量を調整
して変化させた。また、空気温度は10℃である。
なお、微粉炭バーナの構造は第３図に示す本発明
のバーナを用い、一次空気量30Nm3／ｈ、二次空
気量、40Nm3／ｈ、三次空気量60Nm3／ｈで行な
つた。第６図の横軸は微粉炭／一次空気（搬送用
空気）の比率を示す。第６図の結果から、微粉炭
濃度に応じた限界プラズマアーク出力が存在する
こと、プラズマアーク出力を増加していくと、着
火限界が低濃度側に移行していることが判る。し
かし、プラズマアークが出力を増加しても着火で
きない領域が存在し、微粉炭と一次空気の比率が
0.15以下では着火しないため、0.15が微粉炭濃度
から決定される着火限界となる。次に、微粉炭濃
度を増加していくと、プラズマアーク出力は低出
力側で着火できるが、1KW以下になると濃度に
は無関係に着火できなくなり、プラズマアーク出
力から決定される着火限界となる。従つて、第６
図に示すように、着火領域となる範囲内で微粉炭
濃度とプラズマアーク出力を決定することが必要
である。プラズマアークフレームを遮断して火炎
を安定に継続していく上での保炎効果を第７図に
示す。第７図は第６図と同様の条件下で常温で着
火し、プラズマアークフレームを微粉炭空気流に
接触させ、バーナ先端の温度を熱電対を設けて測
定し、バーナ先端の温度とプラズマアークフレー
ムを遮断したときに火炎を形成しているか、ある
いは、消炎したかをバーナ近傍にテレビカメラ
（ITV）を設置して観察したものである。この結
果、バーナ先端の温度が約50℃以下では、プラズ
マアークフレームを遮断すると吹き消えることが
明らかとなつた。約50〜100℃の範囲では、火炎
が存在する場合と、吹き消える場合とがあり不安
定な領域である。次に、バーナ先端部の温度が
100℃以上になると火炎は安定して残り、保炎さ
れる領域となる。従つて、バーナ先端の温度をプ
ラズマアークフレームの遮断する制御因子に利用
すれば、微粉炭の着火後のプラズマアークフレー
ムの運転を制御でき、無駄にエネルギを消費する
こともなくなる。 Next, using Figures 6 and 7, determine the ignition limit of pulverized coal determined by the pulverized coal concentration and plasma arc output, and after ignition, stop the plasma arc flame and continue to form a flame. The conditions for this will be explained based on experimental results. For the experimental results shown in Figures 6 and 7, domestic Pacific coal was used as the pulverized coal, which was adjusted so that the particle size was 80% less than 200 mesh (74 μm). The volatile content in coal is about 38%, the fixed carbon content is also about 38-39%, and the ash content is about 14%. The ejection speed of pulverized coal/air flow is
The speed was constant at 15 m/s, and the pulverized coal concentration was varied by adjusting the pulverized coal supply rate. Also, the air temperature is 10°C.
The structure of the pulverized coal burner was as shown in FIG. 3 using the burner of the present invention, with a primary air amount of 30 Nm 3 /h, a secondary air amount of 40 Nm 3 /h, and a tertiary air amount of 60 Nm 3 /h. The horizontal axis in FIG. 6 shows the ratio of pulverized coal/primary air (conveying air). From the results shown in FIG. 6, it can be seen that there is a limit plasma arc output depending on the pulverized coal concentration, and that as the plasma arc output is increased, the ignition limit shifts to the lower concentration side. However, even if the plasma arc output increases, there is a region where it cannot ignite, and the ratio of pulverized coal to primary air is low.
Since ignition does not occur below 0.15, 0.15 is the ignition limit determined from the pulverized coal concentration. Next, when the pulverized coal concentration is increased, ignition is possible at a low plasma arc output, but when it becomes less than 1KW, ignition becomes impossible regardless of the concentration, and the ignition limit is determined by the plasma arc output. Therefore, the sixth
As shown in the figure, it is necessary to determine the pulverized coal concentration and plasma arc output within the ignition region. Figure 7 shows the flame holding effect in blocking the plasma arc flame and stably continuing the flame. Figure 7 shows ignition at room temperature under the same conditions as Figure 6, the plasma arc flame is brought into contact with the pulverized coal air flow, and the temperature at the burner tip is measured with a thermocouple. A television camera (ITV) was installed near the burner to observe whether a flame was formed or extinguished when the flame was shut off. The results revealed that if the temperature at the burner tip was below about 50°C, the plasma arc flame would be blown out if it was shut off. The range of approximately 50 to 100°C is an unstable region, with flames sometimes existing and sometimes extinguished. Next, the temperature at the burner tip is
When the temperature reaches 100°C or higher, the flame remains stable and becomes a flame-holding region. Therefore, if the temperature at the tip of the burner is used as a control factor for shutting off the plasma arc flame, the operation of the plasma arc flame after ignition of pulverized coal can be controlled, and energy will not be wasted.
本発明によれば、プラズマアークフレームと微
粉炭／空気流との接触を効率良く行なうことがで
き、また、微粉炭／空気流の操作条件で微粉炭の
着火領域内にあることなど、制御面での操作を簡
略化し、安定した微粉炭の着火ができる。
According to the present invention, it is possible to efficiently contact the plasma arc flame with the pulverized coal/air flow, and control aspects such as being within the ignition region of the pulverized coal under the operating conditions of the pulverized coal/air flow can be achieved. This simplifies the operation and enables stable ignition of pulverized coal.
第１図は従来構成図、第２図は従来の問題点の
説明図、第３図ないし第５図は本発明のアーク式
点火トーチを内蔵する微粉炭バーナの構成図、第
６図、第７図は微粉炭の着火及び保炎に必要な条
件を示す実験結果の図である。
１…微粉炭バーナ、２…アーク式点火トーチ、
８…微粉炭／空気流ノズル、９…二次空気ノズ
ル、１０…三次空気ノズル、１１，１２…旋回
路。
Fig. 1 is a conventional configuration diagram, Fig. 2 is an explanatory diagram of conventional problems, Figs. 3 to 5 are configuration diagrams of a pulverized coal burner incorporating an arc type ignition torch of the present invention, FIG. 7 is a diagram showing experimental results showing the conditions necessary for ignition and flame holding of pulverized coal. 1...pulverized coal burner, 2...arc type ignition torch,
8...Pulverized coal/air flow nozzle, 9...Secondary air nozzle, 10...Tertiary air nozzle, 11, 12...Swirl path.
Claims (1)
うにした点火用プラズマトーチを配置し、その外
側に同心円状に微粉炭および一次空気の混合流を
噴出するノズルを設け、さらに、その外側に二次
空気ノズル及び三次空気ノズルを同心円状に配置
し、前記混合流を噴出するノズルの先端部を該混
合流の噴出速度が17m／ｓ以下の時に前記プラズ
マトーチ側に傾斜しそれ以上の噴出速度の時に反
対側に傾斜するように向きが変わりうる構造とし
たことを特徴とするアーク式点火トーチを備えた
微粉炭バーナ。1 An ignition plasma torch that can emit an electric arc flame is placed in the center, and a nozzle that spouts a mixed flow of pulverized coal and primary air concentrically is placed on the outside of the torch, and secondary air is placed on the outside of the torch. A nozzle and a tertiary air nozzle are arranged concentrically, and the tip of the nozzle that ejects the mixed flow is tilted toward the plasma torch when the ejecting speed of the mixed flow is 17 m/s or less, and when the ejecting speed is higher than that. A pulverized coal burner equipped with an arc-type ignition torch characterized by a structure that allows the direction to be changed so as to tilt to the opposite side.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4705984A JPS60194211A (en) | 1984-03-14 | 1984-03-14 | Pulverized coal burner with arc type ignition torch |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4705984A JPS60194211A (en) | 1984-03-14 | 1984-03-14 | Pulverized coal burner with arc type ignition torch |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS60194211A JPS60194211A (en) | 1985-10-02 |
| JPH059684B2 true JPH059684B2 (en) | 1993-02-05 |
Family
ID=12764579
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4705984A Granted JPS60194211A (en) | 1984-03-14 | 1984-03-14 | Pulverized coal burner with arc type ignition torch |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS60194211A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4124838A1 (en) | 2021-07-28 | 2023-02-01 | Hanla IMS Co. Ltd. | Fluid level measurement system using buoyant body |
Families Citing this family (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| AU598147B2 (en) * | 1987-08-13 | 1990-06-14 | Connell Wagner Pty Ltd | Pulverised fuel burner |
| JP2780026B2 (en) * | 1988-07-01 | 1998-07-23 | バブコツク日立株式会社 | Pulverized coal ignition torch |
| FI85910C (en) * | 1989-01-16 | 1992-06-10 | Imatran Voima Oy | FOERFARANDE OCH ANORDNING FOER ATT STARTA PANNAN I ETT KRAFTVERK SOM UTNYTTJAR FAST BRAENSLE SAMT FOER ATT SAEKERSTAELLA FOERBRAENNINGEN AV BRAENSLET. |
| JP5678603B2 (en) * | 2010-11-22 | 2015-03-04 | 株式会社Ihi | Pulverized coal burner |
| JP5708119B2 (en) * | 2011-03-25 | 2015-04-30 | 株式会社Ihi | Pulverized coal burner |
| CN102305415B (en) * | 2011-10-18 | 2013-10-09 | 上海锅炉厂有限公司 | Plasma oil-free ignition system in oxygen-enriched environments |
| DE102011056655B4 (en) * | 2011-12-20 | 2013-10-31 | Alstom Technology Ltd. | Burner for burning a dusty fuel for a boiler with plasma ignition burner |
| JP6160105B2 (en) * | 2013-02-12 | 2017-07-12 | 株式会社Ihi | Pulverized coal burner |
| DE102013111504B4 (en) * | 2013-10-18 | 2017-12-07 | Mitsubishi Hitachi Power Systems Europe Gmbh | Method for igniting a power plant burner and suitable pulverized coal burner |
| EP2908051B1 (en) * | 2014-02-12 | 2021-01-13 | General Electric Technology GmbH | Igniter lance and method for operating a burner having said igniter lance |
-
1984
- 1984-03-14 JP JP4705984A patent/JPS60194211A/en active Granted
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP4124838A1 (en) | 2021-07-28 | 2023-02-01 | Hanla IMS Co. Ltd. | Fluid level measurement system using buoyant body |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS60194211A (en) | 1985-10-02 |
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