JP3799665B2

JP3799665B2 - Pulverized coal burner equipment

Info

Publication number: JP3799665B2
Application number: JP17254796A
Authority: JP
Inventors: 元哉中村
Original assignee: 石川島播磨重工業株式会社
Priority date: 1996-07-02
Filing date: 1996-07-02
Publication date: 2006-07-19
Anticipated expiration: 2016-07-02
Also published as: JPH1019207A

Description

【０００１】
【発明の属する技術分野】
本発明は、微粉炭バーナ装置に関するものである。
【０００２】
【従来の技術】
ミルで粉砕した石炭の微粉を一次空気と混合して微粉炭バーナへ供給し該微粉炭バーナから噴出させて浮遊燃焼させる微粉炭燃焼は、従来から広く一般に用いられている石炭の燃焼方式である。
【０００３】
微粉炭燃焼方式のボイラの火炉に使用されている微粉炭バーナ装置の一例を図４及び図５によって説明すると、火炉１の側壁の所定位置にはスロート２が形成されており、スロート２付近の火炉１の外部にはウインドボックス３が配置されていて、ウインドボックス３から火炉１へ燃焼用の二次空気４を供給するようになっている。
【０００４】
スロート２の中心にはウインドボックス３を貫通する微粉炭バーナ５が設けられていて、微粉炭バーナ５の中心部には、略円筒状で先端開口部に先端に向かって直径が急減する絞り部を有するバーナ内筒６が配置され、バーナ内筒６の軸心位置にはオイルバーナ７が挿入されている。
【０００５】
バーナ内筒６の外側にはバーナ外筒８がバーナ内筒６と同心状に配設されていて、バーナ外筒８は基端部分が略円筒状で、中間部分から先端に向かって直径が漸減する中空円筒状になっている。
【０００６】
バーナ外筒８の先端開口部には、先端に向かって直径が急減するバーナノズル９が取り付けられている。
【０００７】
バーナ外筒８の基端部には、その接線方向へ延びる導入ノズル１９が突設され、該導入ノズル１９には微粉炭管１３が接続されていて、ミル１２から一次空気１１と共に供給される微粉炭１０をバーナ外筒８内へ導くようになっており、バーナ内筒６の基端部外周とバーナ外筒８の基端部内周には、微粉炭管１３から導入ノズル１９を介して供給される微粉炭１０によるバーナ内筒６の基端部外周とバーナ外筒８の基端部内周の摩耗を防止するための耐摩耗材からなるライナ１４が取り付けられている。
【０００８】
前記スロート２とウインドボックス３との間に形成された空間に、二次空気４の旋回力を調整するためのエアレジスタ１５を、スロート２の周りを円形に囲うように配設すると共に、エアレジスタ１５の内側の周方向に、二次空気４を内側と外側とに分離するための複数のインナベーン１６を配設し、更に、ウインドボックス３とバーナ内筒６の基端部とを、三次空気管１８によって連通せしめ、三次空気１７をバーナ内筒６へ導くようにしてある。
【０００９】
図４及び図５に示される如き微粉炭バーナ５においては、ミル１２から微粉炭管１３と導入ノズル１９を介してバーナ外筒８の内部へ一次空気１１と共に供給される微粉炭１０は、バーナ外筒８の後端部において旋回力を与えられ、バーナ内筒６とバーナ外筒８との間の空間内を周方向に旋回しながら先端側へ流動し、バーナノズル９の先端からスロート２へ噴出し、ウインドボックス３から供給される二次空気４と混合され、燃焼が行われるようになっている。
【００１０】
【発明が解決しようとする課題】
しかしながら、図４及び図５に示される如き従来の微粉炭バーナ装置では、バーナ内筒６の外周面に微粉炭１０が付着しやすく、該バーナ内筒６の外周面に付着した微粉炭１０が低温酸化された場合、微粉炭バーナ５内部で発火が起こり、該微粉炭バーナ５が焼損する虞れがあった。
【００１１】
前記バーナ外筒８の後端部から微粉炭バーナ５内へ供給される微粉炭１０の平均粒径は、およそ４０［μｍ］程度であるが、そのうち前記バーナ内筒６の外周面へ付着する微粉炭１０は、比較的細かい粒子（平均粒径１０［μｍ］程度の微粒子）であり、これは、微粉炭管１３がバーナ外筒８の基端部に形成された接線方向に延びる導入ノズル１９に接続され、ミル１２から微粉炭管１３と導入ノズル１９を介してバーナ外筒８の内部へ一次空気１１と共に供給される微粉炭１０が、バーナ外筒８の後端部において旋回力を与えられ、バーナ内筒６とバーナ外筒８との間の空間内を周方向に旋回しながら先端側へ流動して行くため、遠心力により、バーナ外筒８の内周面側ほど粗粒子が多く分布して流れると共に、バーナ内筒６の外周面側ほど微粒子が多く分布して流れることが原因であると考えられる。
【００１２】
本発明は、斯かる実情に鑑み、バーナ内筒外周面における微粉炭の付着、堆積を防止し得、微粉炭バーナが焼損することを回避し得る微粉炭バーナ装置を提供しようとするものである。
【００１３】
【課題を解決するための手段】
第一の発明は、バーナ内筒の外側にバーナ外筒を同心状に配設し、該バーナ外筒の基端部に、その接線方向へ延びる導入ノズルを形成し、該導入ノズルに、ミルで粉砕された微粉炭を供給するようにした微粉炭バーナ装置において、
ミルで粉砕された微粉炭を粗粒子と微粒子とに分離する分級器と、
該分級器で分離された微粉炭の粗粒子をバーナ内筒の外周面近傍へ導く粗粒子管と、
前記分級器で分離された微粉炭の微粒子を導入ノズルへ導く微粒子管と
を備えたことを特徴とする微粉炭バーナ装置にかかるものである。
【００１４】
又、第二の発明は、バーナ内筒の外側にバーナ外筒を同心状に配設し、該バーナ外筒の基端部に、その接線方向へ延びる導入ノズルを形成し、該導入ノズルに、ミルで粉砕された微粉炭を供給するようにした微粉炭バーナ装置において、
ミルで粉砕された微粉炭を供給するための微粉炭管の先端部を所要の曲率で湾曲せしめて導入ノズルに接続し、該微粉炭管の湾曲部分を通過する際に分離される微粉炭の粗粒子をバーナ内筒寄りに導くと共に、前記微粉炭管の湾曲部分を通過する際に分離される微粉炭の微粒子をバーナ外筒寄りに導くよう構成したことを特徴とする微粉炭バーナ装置にかかるものである。
【００１５】
上記手段によれば、以下のような作用が得られる。
【００１６】
第一の発明においては、ミルで粉砕された微粉炭は、分級器において粗粒子と微粒子とに分離され、該分級器で分離された微粉炭の粗粒子は、粗粒子管を介してバーナ内筒の外周面近傍へ導かれると共に、前記分級器で分離された微粉炭の微粒子は、微粒子管を介して導入ノズルへ導かれる。
【００１７】
この結果、前記微粉炭の粗粒子は、バーナ内筒の外周面近傍に沿って先端側へ流れ、前記微粉炭の微粒子は、導入ノズルからバーナ外筒に沿って周方向に旋回しながら先端側へ流れることとなり、前記微粉炭の粗粒子の流れによって前記微粉炭の微粒子がバーナ内筒の外周面に付着しにくくなり、該バーナ内筒の外周面に付着した微粉炭の低温酸化に伴う発火も起こりにくくなり、該微粉炭バーナが焼損しなくなる。
【００１８】
又、前記導入ノズルからバーナ外筒の接線方向へ導入されるのは、微粉炭の微粒子だけとなり、微粉炭の粗粒子のバーナ外筒への衝突頻度が低下するため、バーナ外筒の摩耗も低減されることとなる。
【００１９】
又、第二の発明においては、ミルで粉砕された微粉炭は、微粉炭管の湾曲部分を通過する際に、遠心力により、湾曲部分の外周側ほど粗粒子が多く分布して流れると共に、湾曲部分の内周側ほど微粒子が多く分布して流れるようになり、微粉炭が粗粒子と微粒子とに分離された形で導入ノズルへ導かれる。
【００２０】
この結果、前記微粉炭の粗粒子は、導入ノズルからバーナ内筒寄りに導入され、該バーナ内筒に沿って周方向に旋回しながら先端側へ流れると共に、前記微粉炭の微粒子は、導入ノズルからバーナ外筒寄りに導入され、該バーナ外筒に沿って周方向に旋回しながら先端側へ流れることとなり、前記微粉炭の粗粒子の流れによって前記微粉炭の微粒子がバーナ内筒の外周面に付着しにくくなり、該バーナ内筒の外周面に付着した微粉炭の低温酸化に伴う発火も起こりにくくなり、該微粉炭バーナが焼損しなくなる。
【００２１】
又、この場合、前記導入ノズルからバーナ外筒の接線方向には、微粉炭の粗粒子と微粒子の両方が導入されるが、従来に比べれば、微粉炭の粗粒子のバーナ外筒への衝突頻度が低下するため、バーナ外筒の摩耗も低減されることとなる。
【００２２】
【発明の実施の形態】
以下、本発明の実施の形態を図示例と共に説明する。
【００２３】
図１は本発明を実施する形態の一例であって、図中、図４及び図５と同一の符号を付した部分は同一物を表わしており、ミル１２で粉砕された微粉炭１０を粗粒子と微粒子とに分離するサイクロン等の分級器２０を設け、該分級器２０で分離された微粉炭１０の粗粒子を粗粒子管２１を介してバーナ内筒６の外周面近傍へ導くと共に、前記分級器２０で分離された微粉炭１０の微粒子を微粒子管１３’を介して導入ノズル１９へ導くよう構成する。
【００２４】
次に、上記図示例の作動を説明する。
【００２５】
ミル１２で粉砕された微粉炭１０（平均粒径およそ４０［μｍ］程度）は、分級器２０において粗粒子と微粒子（平均粒径およそ１０［μｍ］程度）とに分離され、該分級器２０で分離された微粉炭１０の粗粒子は、粗粒子管２１を介してバーナ内筒６の外周面近傍へ導かれると共に、前記分級器２０で分離された微粉炭１０の微粒子は、微粒子管１３’を介して導入ノズル１９へ導かれる。
【００２６】
この結果、前記微粉炭１０の粗粒子は、バーナ内筒６の外周面近傍に沿って先端側へ流れ、前記微粉炭１０の微粒子は、導入ノズル１９からバーナ外筒８に沿って周方向に旋回しながら先端側へ流れることとなり、前記微粉炭１０の粗粒子の流れによって前記微粉炭１０の微粒子がバーナ内筒６の外周面に付着しにくくなり、該バーナ内筒６の外周面に付着した微粉炭１０の低温酸化に伴う発火も起こりにくくなり、該微粉炭バーナ５が焼損しなくなる。
【００２７】
又、前記導入ノズル１９からバーナ外筒８の接線方向へ導入されるのは、微粉炭１０の微粒子だけとなり、微粉炭１０の粗粒子のバーナ外筒８への衝突頻度が低下するため、バーナ外筒８のライナ１４が設けられた部分の摩耗も低減されることとなる。
【００２８】
こうして、バーナ内筒６外周面における微粉炭１０の付着、堆積を防止し得、微粉炭バーナ５が焼損することを回避し得、更に、微粉炭１０の粗粒子によるバーナ外筒８の摩耗を低減でき、微粉炭バーナ５の寿命延長にも役立つ。
【００２９】
図２及び図３は本発明を実施する形態の他の例であって、図中、図４及び図５と同一の符号を付した部分は同一物を表わしており、基本的な構成は図４及び図５に示す従来のものと同様であるが、本図示例の特徴とするところは、図２及び図３に示す如く、ミル１２で粉砕された微粉炭１０を供給するための微粉炭管１３”の先端部を所要の曲率で湾曲せしめて導入ノズル１９に接続し、該微粉炭管１３”の湾曲部分を通過する際に分離される微粉炭１０の粗粒子をバーナ内筒６寄りに導くと共に、前記微粉炭管１３”の湾曲部分を通過する際に分離される微粉炭１０の微粒子をバーナ外筒８寄りに導くよう構成した点にある。
【００３０】
図２及び図３に示す例においては、ミル１２で粉砕された微粉炭１０は、微粉炭管１３”の湾曲部分を通過する際に、遠心力により、湾曲部分の外周側ほど粗粒子が多く分布して流れると共に、湾曲部分の内周側ほど微粒子が多く分布して流れるようになり、微粉炭１０が粗粒子と微粒子とに分離された形で導入ノズル１９へ導かれる。
【００３１】
この結果、前記微粉炭１０の粗粒子は、導入ノズル１９からバーナ内筒６寄りに導入され、該バーナ内筒６に沿って周方向に旋回しながら先端側へ流れると共に、前記微粉炭１０の微粒子は、導入ノズル１９からバーナ外筒８寄りに導入され、該バーナ外筒８に沿って周方向に旋回しながら先端側へ流れることとなり、前記微粉炭１０の粗粒子の流れによって前記微粉炭１０の微粒子がバーナ内筒６の外周面に付着しにくくなり、該バーナ内筒６の外周面に付着した微粉炭１０の低温酸化に伴う発火も起こりにくくなり、該微粉炭バーナ５が焼損しなくなる。
【００３２】
又、この場合、前記導入ノズル１９からバーナ外筒８の接線方向には、微粉炭１０の粗粒子と微粒子の両方が導入されるが、従来に比べれば、微粉炭１０の粗粒子のバーナ外筒８への衝突頻度が低下するため、バーナ外筒８のライナ１４が設けられた部分の摩耗も低減されることとなる。
【００３３】
こうして、図２及び図３に示す例の場合にも、バーナ内筒６外周面における微粉炭１０の付着、堆積を防止し得、微粉炭バーナ５が焼損することを回避し得、更に、微粉炭１０の粗粒子によるバーナ外筒８の摩耗を低減でき、微粉炭バーナ５の寿命延長にも役立つ。又、図２及び図３に示す例の場合には、図１の例の場合のように分級器２０等を設ける必要がなく、先端部を所要の曲率で湾曲せしめた微粉炭管１３”を用いるだけの簡単な変更で済むため、既設の設備を改造するようなときには有利となる。
【００３４】
尚、本発明の微粉炭バーナ装置は、上述の図示例にのみ限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００３５】
【発明の効果】
以上、説明したように本発明の請求項１記載の微粉炭バーナ装置によれば、バーナ内筒外周面における微粉炭の付着、堆積を防止し得、微粉炭バーナが焼損することを回避し得、更に、微粉炭の粗粒子によるバーナ外筒の摩耗を低減でき、微粉炭バーナの寿命延長にも役立つという優れた効果を奏し得、又、本発明の請求項２記載の微粉炭バーナ装置によれば、上記効果に加え更に、先端部を所要の曲率で湾曲せしめた微粉炭管を用いるだけの簡単な変更で済むため、既設の設備を改造するようなときには有利となるという優れた効果を奏し得る。
【図面の簡単な説明】
【図１】本発明を実施する形態の一例の側断面図である。
【図２】本発明を実施する形態の他の例の側断面図である。
【図３】図２のＩＩＩ−ＩＩＩ断面図である。
【図４】従来例の側断面図である。
【図５】図４のＶ−Ｖ断面図である。
【符号の説明】
５微粉炭バーナ
６バーナ内筒
８バーナ外筒
１０微粉炭
１２ミル
１３’ 微粒子管
１３” 微粉炭管
１９導入ノズル
２０分級器
２１粗粒子管[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pulverized coal burner device.
[0002]
[Prior art]
The pulverized coal combustion, in which fine powder of coal pulverized by a mill is mixed with primary air, supplied to the pulverized coal burner, ejected from the pulverized coal burner, and suspended in combustion, is a coal combustion method that has been widely used conventionally. .
[0003]
An example of the pulverized coal burner used in the furnace of a pulverized coal combustion type boiler will be described with reference to FIGS. 4 and 5. A throat 2 is formed at a predetermined position on the side wall of the furnace 1. A wind box 3 is disposed outside the furnace 1, and secondary air 4 for combustion is supplied from the wind box 3 to the furnace 1.
[0004]
A pulverized coal burner 5 penetrating the wind box 3 is provided at the center of the throat 2, and at the center of the pulverized coal burner 5 is a throttle portion that is substantially cylindrical and has a diameter that suddenly decreases toward the tip opening. The burner inner cylinder 6 having the above is disposed, and an oil burner 7 is inserted in the axial center position of the burner inner cylinder 6.
[0005]
A burner outer cylinder 8 is disposed concentrically with the burner inner cylinder 6 on the outer side of the burner inner cylinder 6. The burner outer cylinder 8 has a substantially cylindrical base end portion and a diameter from the intermediate portion toward the distal end. It has a hollow cylindrical shape that gradually decreases.
[0006]
A burner nozzle 9 whose diameter decreases rapidly toward the tip is attached to the tip opening of the burner outer cylinder 8.
[0007]
An introductory nozzle 19 extending in the tangential direction protrudes from the proximal end portion of the burner outer cylinder 8. A pulverized coal pipe 13 is connected to the introductory nozzle 19 and is supplied from the mill 12 together with the primary air 11. The pulverized coal 10 is guided into the burner outer cylinder 8, and the basal end outer periphery of the burner inner cylinder 6 and the basal end inner periphery of the burner outer cylinder 8 are introduced from the pulverized coal pipe 13 through the introduction nozzle 19. A liner 14 made of a wear-resistant material for preventing the outer periphery of the base end portion of the burner inner cylinder 6 and the inner periphery of the base end portion of the burner outer cylinder 8 from being supplied with the pulverized coal 10 is attached.
[0008]
An air register 15 for adjusting the turning force of the secondary air 4 is disposed in a space formed between the throat 2 and the wind box 3 so as to surround the throat 2 in a circular shape, and the air A plurality of inner vanes 16 for separating the secondary air 4 into an inner side and an outer side are arranged in the circumferential direction inside the register 15, and further, the wind box 3 and the base end portion of the burner inner cylinder 6 are connected to the tertiary. The air pipe 18 communicates with each other so that the tertiary air 17 is guided to the burner inner cylinder 6.
[0009]
In the pulverized coal burner 5 as shown in FIGS. 4 and 5, the pulverized coal 10 supplied together with the primary air 11 from the mill 12 to the inside of the burner outer cylinder 8 through the pulverized coal pipe 13 and the introduction nozzle 19 is the burner. A turning force is applied to the rear end portion of the outer cylinder 8, and it flows to the tip side while turning in the circumferential direction in the space between the burner inner cylinder 6 and the burner outer cylinder 8, and from the tip of the burner nozzle 9 to the throat 2. It is jetted out and mixed with the secondary air 4 supplied from the wind box 3, and combustion is performed.
[0010]
[Problems to be solved by the invention]
However, in the conventional pulverized coal burner apparatus as shown in FIGS. 4 and 5, the pulverized coal 10 tends to adhere to the outer peripheral surface of the burner inner cylinder 6, and the pulverized coal 10 attached to the outer peripheral surface of the burner inner cylinder 6 When it is oxidized at low temperature, there is a possibility that ignition occurs inside the pulverized coal burner 5 and the pulverized coal burner 5 is burned out.
[0011]
The average particle diameter of the pulverized coal 10 supplied from the rear end portion of the burner outer cylinder 8 into the pulverized coal burner 5 is about 40 [μm], and of these, it adheres to the outer peripheral surface of the burner inner cylinder 6. The pulverized coal 10 is relatively fine particles (fine particles having an average particle size of about 10 [μm]), and this is an introduction nozzle in which the pulverized coal pipe 13 extends in the tangential direction formed at the base end portion of the burner outer cylinder 8. The pulverized coal 10 supplied to the inside of the burner outer cylinder 8 from the mill 12 through the pulverized coal pipe 13 and the introduction nozzle 19 together with the primary air 11 has a turning force at the rear end portion of the burner outer cylinder 8. Given to the inner peripheral surface side of the burner outer cylinder 8 due to centrifugal force because it flows to the tip side while turning in the circumferential direction in the space between the burner inner cylinder 6 and the burner outer cylinder 8. Is distributed in a large amount and the outer peripheral surface side of the burner inner cylinder 6 This is considered to be caused by a large amount of fine particles distributed and flowing.
[0012]
In view of such circumstances, the present invention intends to provide a pulverized coal burner device that can prevent pulverized coal from adhering and accumulating on the outer peripheral surface of a burner inner cylinder and avoid burning the pulverized coal burner. .
[0013]
[Means for Solving the Problems]
According to a first aspect of the present invention, a burner outer cylinder is concentrically disposed outside the burner inner cylinder, and an introduction nozzle extending in a tangential direction is formed at a base end portion of the burner outer cylinder. In the pulverized coal burner device that supplies pulverized coal pulverized in
A classifier for separating pulverized coal pulverized by a mill into coarse particles and fine particles;
A coarse particle tube for guiding coarse particles of pulverized coal separated by the classifier to the vicinity of the outer peripheral surface of the burner inner cylinder;
The present invention relates to a pulverized coal burner device comprising a fine particle pipe for guiding fine particles of pulverized coal separated by the classifier to an introduction nozzle.
[0014]
According to a second aspect of the present invention, a burner outer cylinder is concentrically disposed outside the burner inner cylinder, and an introduction nozzle extending in the tangential direction is formed at the base end of the burner outer cylinder. In the pulverized coal burner device that supplies pulverized coal pulverized by a mill,
The tip of the pulverized coal pipe for supplying the pulverized coal pulverized by the mill is bent with a required curvature and connected to the introduction nozzle, and the pulverized coal separated when passing through the curved portion of the pulverized coal pipe A pulverized coal burner apparatus configured to guide coarse particles closer to an inner cylinder of a burner and guide fine particles of pulverized coal separated when passing through a curved portion of the pulverized coal pipe toward an outer cylinder of the burner. It is such a thing.
[0015]
According to the above means, the following operation can be obtained.
[0016]
In the first invention, the pulverized coal pulverized by the mill is separated into coarse particles and fine particles by a classifier, and the coarse particles of the pulverized coal separated by the classifier are disposed in the burner through the coarse particle tube. While being guided to the vicinity of the outer peripheral surface of the cylinder, the fine particles of the pulverized coal separated by the classifier are guided to the introduction nozzle through the fine particle tube.
[0017]
As a result, the coarse particles of the pulverized coal flow toward the tip side along the vicinity of the outer peripheral surface of the burner inner cylinder, and the fine particles of the pulverized coal turn to the tip side while turning in the circumferential direction along the burner outer cylinder from the introduction nozzle. The flow of coarse particles of the pulverized coal makes it difficult for the fine particles of the pulverized coal to adhere to the outer peripheral surface of the burner inner cylinder, and ignition accompanied by low-temperature oxidation of the pulverized coal attached to the outer peripheral surface of the burner inner cylinder And the pulverized coal burner will not burn out.
[0018]
In addition, only fine particles of pulverized coal are introduced from the introduction nozzle in the tangential direction of the burner outer cylinder, and the frequency of collision of coarse particles of pulverized coal with the burner outer cylinder is reduced, so that the burner outer cylinder is also worn. It will be reduced.
[0019]
Further, in the second invention, when the pulverized coal pulverized by the mill passes through the curved portion of the pulverized coal pipe, the centrifugal force causes a distribution of coarse particles toward the outer peripheral side of the curved portion, and flows. Fine particles are distributed and flow toward the inner peripheral side of the curved portion, and the pulverized coal is guided to the introduction nozzle in a form separated into coarse particles and fine particles.
[0020]
As a result, the coarse particles of the pulverized coal are introduced from the introduction nozzle closer to the inner cylinder of the burner and flow to the tip side while turning in the circumferential direction along the inner cylinder of the burner. Is introduced near the outer cylinder of the burner and flows to the tip side while turning in the circumferential direction along the outer cylinder of the burner, and the fine particles of the pulverized coal are flown to the outer peripheral surface of the inner cylinder of the burner by the flow of coarse particles of the pulverized coal. The pulverized coal burner is less likely to be ignited due to low temperature oxidation of the pulverized coal adhering to the outer peripheral surface of the burner inner cylinder, and the pulverized coal burner is not burned out.
[0021]
In this case, both coarse particles and fine particles of pulverized coal are introduced in the tangential direction of the burner outer cylinder from the introduction nozzle, but compared to the conventional case, the coarse particles of pulverized coal collide with the burner outer cylinder. Since the frequency decreases, wear of the burner outer cylinder is also reduced.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0023]
FIG. 1 shows an example of an embodiment of the present invention. In the figure, the parts denoted by the same reference numerals as those in FIGS. 4 and 5 represent the same thing, and the pulverized coal 10 crushed by the mill 12 is roughly A classifier 20 such as a cyclone that separates the particles into fine particles is provided, and the coarse particles of the pulverized coal 10 separated by the classifier 20 are guided to the vicinity of the outer peripheral surface of the burner inner cylinder 6 through the coarse particle tube 21, The fine particles of the pulverized coal 10 separated by the classifier 20 are configured to be guided to the introduction nozzle 19 through the fine particle tube 13 ′.
[0024]
Next, the operation of the illustrated example will be described.
[0025]
The pulverized coal 10 (average particle size of about 40 [μm]) pulverized by the mill 12 is separated into coarse particles and fine particles (average particle size of about 10 [μm]) in the classifier 20, and the classifier 20 The coarse particles of the pulverized coal 10 separated in (1) are guided to the vicinity of the outer peripheral surface of the burner inner cylinder 6 through the coarse particle tube 21, and the fine particles of the pulverized coal 10 separated by the classifier 20 are dispersed in the fine particle tube 13. It is guided to the introduction nozzle 19 through '.
[0026]
As a result, the coarse particles of the pulverized coal 10 flow toward the tip side along the vicinity of the outer peripheral surface of the burner inner cylinder 6, and the fine particles of the pulverized coal 10 flow in the circumferential direction along the burner outer cylinder 8 from the introduction nozzle 19. The fine particles of the pulverized coal 10 are less likely to adhere to the outer peripheral surface of the burner inner cylinder 6 due to the flow of coarse particles of the pulverized coal 10 and turn to the outer peripheral surface of the burner inner cylinder 6. Ignition accompanying low temperature oxidation of the pulverized coal 10 is less likely to occur, and the pulverized coal burner 5 is not burned out.
[0027]
Further, only the fine particles of the pulverized coal 10 are introduced from the introduction nozzle 19 in the tangential direction of the burner outer cylinder 8, and the frequency of collision of coarse particles of the pulverized coal 10 with the burner outer cylinder 8 is reduced. Wear of the portion of the outer cylinder 8 provided with the liner 14 is also reduced.
[0028]
Thus, adhesion and accumulation of the pulverized coal 10 on the outer peripheral surface of the burner inner cylinder 6 can be prevented, burning of the pulverized coal burner 5 can be avoided, and further, the wear of the burner outer cylinder 8 due to coarse particles of the pulverized coal 10 can be prevented. It can be reduced and is useful for extending the life of the pulverized coal burner 5.
[0029]
2 and 3 are other examples of embodiments of the present invention. In the figure, the same reference numerals as those in FIGS. 4 and 5 denote the same components, and the basic configuration is shown in FIG. 4 and 5 are the same as those of the prior art shown in FIG. 5, but the feature of the illustrated example is that the pulverized coal for supplying the pulverized coal 10 crushed by the mill 12 as shown in FIG. 2 and FIG. The tip of the pipe 13 ″ is bent with a required curvature and connected to the introduction nozzle 19, and coarse particles of the pulverized coal 10 separated when passing through the curved portion of the pulverized coal pipe 13 ″ are closer to the burner inner cylinder 6. And the fine particles of the pulverized coal 10 separated when passing through the curved portion of the pulverized coal pipe 13 ″ are guided toward the burner outer cylinder 8.
[0030]
In the example shown in FIGS. 2 and 3, the pulverized coal 10 pulverized by the mill 12 has more coarse particles toward the outer peripheral side of the curved portion due to centrifugal force when passing through the curved portion of the pulverized coal pipe 13 ″. While flowing in a distributed manner, more fine particles are distributed and flow toward the inner peripheral side of the curved portion, and the pulverized coal 10 is guided to the introduction nozzle 19 in a form separated into coarse particles and fine particles.
[0031]
As a result, the coarse particles of the pulverized coal 10 are introduced from the introduction nozzle 19 toward the burner inner cylinder 6 and flow toward the tip side while turning in the circumferential direction along the burner inner cylinder 6. Fine particles are introduced from the introduction nozzle 19 toward the burner outer cylinder 8 and flow toward the tip side while turning in the circumferential direction along the burner outer cylinder 8, and the pulverized coal is flown by the flow of coarse particles of the pulverized coal 10. 10 fine particles are less likely to adhere to the outer peripheral surface of the burner inner cylinder 6, and igniting due to low temperature oxidation of the pulverized coal 10 adhering to the outer peripheral surface of the burner inner cylinder 6 is less likely to occur, causing the pulverized coal burner 5 to burn out. Disappear.
[0032]
In this case, both coarse particles and fine particles of the pulverized coal 10 are introduced in the tangential direction of the burner outer cylinder 8 from the introduction nozzle 19. Since the frequency of collision with the cylinder 8 is reduced, wear of the portion of the burner outer cylinder 8 provided with the liner 14 is also reduced.
[0033]
2 and FIG. 3, in the case of the example shown in FIGS. 2 and 3, adhesion and accumulation of the pulverized coal 10 on the outer peripheral surface of the burner inner cylinder 6 can be prevented, and the pulverized coal burner 5 can be prevented from being burned out. The wear of the burner outer cylinder 8 due to the coarse particles of the charcoal 10 can be reduced, which is useful for extending the life of the pulverized coal burner 5. In the case of the example shown in FIGS. 2 and 3, it is not necessary to provide the classifier 20 or the like as in the case of FIG. 1, and a pulverized coal pipe 13 ″ having a curved end is curved with a required curvature. This is advantageous when remodeling existing equipment because it requires only simple changes.
[0034]
In addition, the pulverized coal burner device of the present invention is not limited to the above-described illustrated examples, and it is needless to say that various modifications can be made without departing from the gist of the present invention.
[0035]
【The invention's effect】
As described above, according to the pulverized coal burner device according to claim 1 of the present invention, it is possible to prevent the pulverized coal from adhering and accumulating on the outer peripheral surface of the inner cylinder of the burner, and to avoid burning the pulverized coal burner. Furthermore, the wear of the burner outer cylinder due to coarse particles of pulverized coal can be reduced, and the excellent effect of helping to extend the life of the pulverized coal burner can be obtained. In addition, the pulverized coal burner apparatus according to claim 2 of the present invention According to this, in addition to the above effect, since it is only necessary to make a simple change by using a pulverized coal pipe whose tip is curved with a required curvature, the excellent effect of being advantageous when remodeling existing equipment is provided. Can play.
[Brief description of the drawings]
FIG. 1 is a side sectional view of an example of an embodiment for carrying out the present invention.
FIG. 2 is a side sectional view of another example of an embodiment for carrying out the present invention.
3 is a cross-sectional view taken along the line III-III in FIG.
FIG. 4 is a side sectional view of a conventional example.
5 is a cross-sectional view taken along line VV in FIG.
[Explanation of symbols]
5 pulverized coal burner 6 burner inner cylinder 8 burner outer cylinder 10 pulverized coal 12 mill 13 'fine particle tube 13 "pulverized coal tube 19 introducing nozzle 20 classifier 21 coarse particle tube

Claims

A burner outer cylinder is concentrically arranged outside the burner inner cylinder, an introduction nozzle extending in the tangential direction is formed at the base end of the burner outer cylinder, and pulverized coal pulverized by a mill at the introduction nozzle In the pulverized coal burner device to supply
A classifier for separating pulverized coal pulverized by a mill into coarse particles and fine particles;
A coarse particle tube for guiding coarse particles of pulverized coal separated by the classifier to the vicinity of the outer peripheral surface of the burner inner cylinder;
A pulverized coal burner device comprising: a fine particle pipe for guiding fine particles of pulverized coal separated by the classifier to an introduction nozzle.

A burner outer cylinder is concentrically arranged outside the burner inner cylinder, an introduction nozzle extending in the tangential direction is formed at the base end of the burner outer cylinder, and pulverized coal pulverized by a mill at the introduction nozzle In the pulverized coal burner device to supply
The tip of the pulverized coal pipe for supplying the pulverized coal pulverized by the mill is bent with a required curvature and connected to the introduction nozzle, and the pulverized coal separated when passing through the curved portion of the pulverized coal pipe A pulverized coal burner apparatus configured to guide coarse particles closer to a burner inner cylinder and to guide fine particles of pulverized coal separated when passing through a curved portion of the pulverized coal pipe toward a burner outer cylinder.