JP2004044895A

JP2004044895A - Fire grate type waste incinerator

Info

Publication number: JP2004044895A
Application number: JP2002202160A
Authority: JP
Inventors: Takahiro Kayama; 香山　貴弘; Michio Nagaseki; 永関　三千男; Masaaki Nishino; 西野　雅明
Original assignee: JFE Engineering Corp
Current assignee: JFE Engineering Corp
Priority date: 2002-07-11
Filing date: 2002-07-11
Publication date: 2004-02-12
Anticipated expiration: 2022-07-11
Also published as: JP3912209B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire grate type waste incinerator where fire grates are not damaged and capable of heightening the quality of incineration ash by removing hazardous substances. <P>SOLUTION: The fire grate type waste incinerator includes three kinds of fire grate consisting of water-cooled fire grates, fire grates which can change between water-cooling and air-cooling, and air-cooled fire grates. The disposition of the fire grates is partitioned into a water-cooled area A having the water-cooled fire grates, a water-cooling/air-cooling change area B having the fire grates which can change the water-cooling and air-cooling, and an air-cooled area C having the air-cooled fire grates. The fire grates in the water-cooling/air-cooling change area B are such constituted that a fire grate positioned on the upstream of a main combustion completion point performs as the water-cooled fire grate and that a fire grate positioned on the downstream of the main combustion completion point performs as the air-cooled fire grate following movement of the main combustion completion point. <P>COPYRIGHT: (C)2004,JPO

Description

【０００１】
【発明の属する技術分野】
本発明は水冷火格子と空冷火格子を備えた火格子式廃棄物焼却炉に関する。
【０００２】
【従来の技術】
都市ごみなどを焼却する火格子式廃棄物焼却炉においては、火格子が、定位置に固定されている固定火格子と往復運動をする可動火格子が一部重なった状態で交互に配置されている。このため、火格子上へ装入された廃棄物は可動火格子の往復運動に伴って、廃棄物が装入される上流側から焼却灰になって排出される出口側（下流側）へ向かって移動するようになっている。
【０００３】
このような火格子式焼却炉により廃棄物を焼却処理する場合、廃棄物ホッパーから火格子上へ装入された廃棄物が乾燥及び熱分解が行われる乾燥領域、火炎を発生する燃焼が行われる主燃焼領域、及び熾燃焼が行われる後燃焼領域を通過して燃焼が完了し、焼却灰になって排出される。
【０００４】
このような火格子式焼却炉においては、火格子はその下に設けられている風箱から吹き込まれる燃焼用空気によって冷却され、耐熱性が付与されている（空冷火格子）。しかし、特に、燃焼領域の火格子については、高熱による損傷を防止するために、水冷構造になっている焼却炉がある。
【０００５】
水冷構造の火格子を備えた焼却炉においては、一般に、乾燥火格子、燃焼火格子、後燃焼火格子に区分されている火格子群のうち、乾燥火格子と燃焼火格子が水冷構造になっている。
【０００６】
【発明が解決しようとする課題】
しかし、プラスチックなどのような発熱量が非常に高いものが投入されたり、無機物の占める割合が多い低発熱量のものが投入されたりする。又、投入される廃棄物には、燃焼性のよいものと、燃焼性のわるいものとがある。そして、投入される廃棄物の性状に関わる上記の変動は季節が変わることによっても起こる。
【０００７】
このため、火炎を生じる廃棄物の燃焼（主燃焼）が完了した箇所（以下、主燃焼完了点という）が、常に、水冷構造に構成されている燃焼火格子の下流側端部に存在している訳ではなく、移動する。そして、主燃焼完了点の移動によって、次のような問題が発生する。
【０００８】
例えば、廃棄物の燃焼速度が速い場合には、主燃焼完了点が燃焼火格子の下流側端部よりも上流側（廃棄物投入側）に存在するようになる。これにより、主燃焼完了点よりも下流側の燃焼火格子上に存在する焼却灰が過度に冷却されてしまい、未燃分の燃焼が十分に行われなくなる。又、焼却灰の温度が低下してしまうので、ダイオキシン類が揮散されなくなったりして、焼却灰の無害化が不十分になり、焼却灰の質が低下する。
【０００９】
又、廃棄物の燃焼速度が遅い場合には、主燃焼完了点が燃焼火格子の下流側端部よりも下流側、すなわち空冷構造の後燃焼火格子上まで下がってしまう。この際、後燃焼火格子の上流側では、設計時には想定していなかった主燃焼が行われるので、その部分の火格子が高温に曝されて損傷する。
【００１０】
本発明は、上記の問題を解決し、火格子が損傷されず、又、有害物質を除去して焼却灰の質を高めることができる火格子式廃棄物焼却炉を提供することを目的とする。
【００１１】
【課題を解決するための手段】
上記の課題を解決するために、請求項１に記載の発明は、水冷火格子と空冷火格子を備えた火格子式廃棄物焼却炉において、水冷火格子、水冷と空冷の切替え可能な火格子、空冷火格子からなる３種類の火格子を有し、火格子の配置が、水冷火格子を備えた水冷区域と、水冷と空冷の切替え可能な火格子を備えた水冷−空冷切替え区域と、空冷火格子を備えた空冷区域に区分されていることを特徴としている。
【００１２】
請求項２に記載の発明は、請求項１に記載の発明において、水冷−空冷切替え区域が、主燃焼完了点の移動範囲を含む範囲に設けられていることを特徴としている。
【００１３】
請求項３に記載の発明は、請求項２に記載の発明において、水冷−空冷切替え区域の火格子が、主燃焼完了点の移動に追従して、主燃焼完了点よりも上流側に位置する火格子が水冷火格子として機能し、主燃焼完了点の下流側に位置する火格子が空冷火格子として機能するように構成されたことを特徴としている。
【００１４】
請求項４に記載の発明は、水冷火格子と空冷火格子を備えた火格子式廃棄物焼却炉において、水冷火格子、冷却水量調節可能な水冷火格子、空冷火格子からなる３種類の火格子を有し、火格子の配置が、水冷火格子を備えた水冷区域と、冷却水量調節可能な水冷火格子を備えた水量調節水冷区域と、空冷火格子を備えた空冷区域に区分されると共に、水量調節水冷区域が主燃焼完了点の移動範囲を含む範囲に設けられており、主燃焼完了点の下流側に位置する火格子に供給する冷却水量が、前記火格子に設けられた温度計の測定値に基づいて前記火格子の温度が所定範囲になるように調節されるように構成されたことを特徴としている。
【００１５】
請求項５に記載の発明は、請求項２又は請求項３に記載の発明において、水冷−空冷切替え区域の各火格子に設けた温度計、前記各火格子から排出された冷却水の温度を測定する温度計、輝度計等の前記火格子上の火炎の範囲を測定する装置、放射温度計等の前記各火格子上の灰の温度を測定する装置のうちの何れかの測定装置を備え、前記何れかの測定装置により測定された測定値に基づいて主燃焼完了点が存在する火格子を検知する主燃焼完了点検知手段を備えたことを特徴としている。
【００１６】
請求項６に記載の発明は、請求項４に記載の発明において、水量調節水冷区域の各火格子に設けた温度計、前記各火格子から排出された冷却水の温度を測定する温度計、輝度計等の前記火格子上の火炎の範囲を測定する装置、放射温度計等の前記各火格子上の灰の温度を測定する装置のうちの何れかの測定装置を備え、前記何れかの測定装置により測定された測定値に基づいて主燃焼完了点が存在する火格子を検知する主燃焼完了点検知手段を備えたことを特徴としている。
【００１７】
本発明においては、主燃焼完了点の移動範囲を含む範囲（主燃焼完了点の前後にわたる区域）に、水冷と空冷の切替え可能な火格子を備えた水冷−空冷切替え区域が設けられており、さらに、主燃焼完了点検知手段を有し、これによって主燃焼完了点が存在する火格子が検知できるようになっている。
【００１８】
このため、水冷−空冷切替え区域の火格子が状況に応じて水冷から空冷に、又は空冷から水冷に切替えられ、火格子上の焼却灰が過度に冷却されたり、火格子が過熱されて損傷したりする問題は発生しなくなる。すなわち、主燃焼完了点が移動した際に、主燃焼完了点が存在する火格子よりも上流側に位置する火格子には冷却水を供給して水冷火格子として機能させ、主燃焼完了点が存在する火格子の下流側に位置する火格子には冷却水の供給を停止し、その火格子を空冷火格子として機能させることができる。
【００１９】
又、本発明においては、主燃焼完了点の前後にわたって、冷却水量調節可能な水冷火格子を備えた水量調節水冷区域が設けられおり、主燃焼完了点の下流側に位置する各火格子に供給する冷却水量が、各火格子に設けられた温度計の測定値に基づいてそれぞれの火格子の温度が所定値になるように調節されるようになっている。このため、主燃焼完了点の下流側に位置する火格子が適度に冷却され、その温度が適切な範囲に維持される。
【００２０】
なお、水冷−空冷切替え区域又は水量調節水冷区域の火格子のうち、主燃焼完了点の下流側に位置する火格子は、水冷−空冷の切替えが行われたり、あるいは冷却水量が調節されたりして、温度が２００℃〜５００℃の範囲になるように調節される。火格子温度を高温に保持することにより、火格子上の焼却灰の温度を高温に維持することができる。
【００２１】
上記のように、本発明においては、移動する主燃焼完了点の位置を検知し、水冷−空冷切替え区域又は水量調節水冷区域の火格子のうち、主燃焼完了点よりも上流側の火格子を水冷火格子として機能させるので、水冷区域の火格子と同様に、高温による損傷を防止できる。
【００２２】
又、移動する主燃焼完了点の位置を検知し、その主燃焼完了点とその下流側の火格子を空冷火格子として機能させたり、あるいはそれらに供給する冷却水の供給量を調節することにより、熾燃焼時の焼却灰が過度に冷却されることなく、適切な温度に維持することができるので、主燃焼完了点の下流側においては、焼却灰の無害化処理が行われる。例えば、焼却灰が４００℃以上に維持されることにより、ダイオキシン類が揮散して減少する。又、焼却灰が６００℃以上に維持されることにより、鉛（Ｐｂ）が酸化して酸化物（ＰｂＯ、ＰｂＯ_２　）になる反応が進行し、焼却灰からの鉛の溶出が抑制される。
【００２３】
【発明の実施の形態】
図１は本発明の火格子式廃棄物焼却炉の構成に係る実施の形態の一例を示す図である。図１において、１０は火格子式焼却炉、１１は主燃焼室、１６は二次燃焼室である。又、１２は廃棄物ホッパー、１３は廃棄物装入装置、１４は火格子、１５は焼却灰４１を排出する焼却灰排出シュートである。４０は廃棄物を示す。
【００２４】
火格子１４は、水冷火格子１４ａ、水冷と空冷の切替え可能な火格子１４ｂ、空冷火格子１４ｃの３種類からなり、火格子上の配置が、水冷火格子１４ａを備えた水冷区域Ａと、水冷と空冷の切替え可能な火格子１４ｂを備えた水冷−空冷切替え区域Ｂと、空冷火格子１４ｃを備えた空冷区域Ｃに区分されている。水冷−空冷切替え区域Ｂは主燃焼完了点の移動範囲を含む範囲に設けられている。この主燃焼完了点の移動範囲を含む範囲を、従来の火格子式焼却炉における区分に当てはめると、燃焼火格子の区域の下流側の一部と後燃焼火格子の区域の上流側の一部に渡る範囲に相当する。
【００２５】
上記各火格子１４ａ、１４ｂ、１４ｃには、それぞれ燃焼用空気を供給するための風箱（図示せず）が設けられており、風箱に供給された燃焼用空気が各火格子から吹出して火格子上の廃棄物に燃焼用の酸素が供給されると共に、燃焼用空気により火格子が冷却されるようになっている。
【００２６】
又、上記各火格子１４ａ、１４ｂ、１４ｃは固定火格子と可動火格子が交互に配置された構成になっており、水冷区域Ａと水冷と水冷−空冷切替え区域Ｂの火格子は水冷構造になっている。そして、水冷−空冷切替え区域Ｂに配置されている火格子は冷却水が供給されることにより水冷火格子として機能し、冷却水の供給を停止することにより空冷火格子として機能するようになっている。
【００２７】
図２は水冷−空冷切替え区域の火格子を適度に冷却する方法に係る一例を示す図である。この図は水冷−空冷切替え区域の一部の火格子を示し、２０は固定火格子、２１は可動火格子である。水冷−空冷切替え区域に配置されている火格子２０は何れも中空構造になっており、冷却水を流通させる流路が設けられている。そして、各火格子に接続された冷却水配管２２にはそれぞれ流量遮断弁２３が設けられている。又、各固定火格子２０には、温度センサーとして熱電対２４を取り付けた温度計２５が設けられており、各火格子の温度が連続的に測定されるようになっている。
【００２８】
上記のように構成された水冷−空冷切替え区域の火格子において、各固定火格子２０に設けられた温度計２５により測定された温度測定値の信号が主燃焼完了点検知装置２６へ送られる。主燃焼完了点検知装置２６では、各温度計２５で測定された温度測定値に基づいて主燃焼完了点が存在する火格子が検知される。次いで、主燃焼完了点検知装置２６から主燃焼完了点が存在する火格子の位置を示す信号が制御器２７へ送られ、制御器２７では、各火格子に接続されている冷却水配管の流量遮断弁２３へ、弁を開にする信号、又は、弁を閉にする信号が発信される。
【００２９】
これにより、主燃焼完了点より上流側の火格子のうち、冷却水が供給されていなかった火格子があった場合には、その火格子に冷却水の供給が開始され、その火格子が水冷火格子として使用される。又、主燃焼完了点より下流側の火格子のうち、冷却水が供給されていた火格子があった場合には、その火格子に供給されていた冷却水が停止され、その火格子が空冷火格子として使用される。このように、水冷−空冷切替え区域においては、主燃焼完了点が移動する度に、火格子が水冷から空冷又は空冷から水冷に適宜切替えられるので、火格子が常に適度に冷却される。
【００３０】
上記主燃焼完了点の検知は次のように行われる。火格子上の廃棄物の主燃焼が完了し、熾燃焼に移行すると、灰の温度が低下するので、その箇所の火格子の温度が降下する。このため、温度が降下した火格子より１段上流側の火格子で主燃焼が完了しているものと判定される。
【００３１】
なお、図２においては、各火格子に設けた温度計による測定値を用いて、主燃焼完了点を検知する方法について説明したが、主燃焼完了点を検知するための方法が火格子の温度に限定されるものではない。例えば、主燃焼が完了した箇所においては、火格子の温度だけでなく、各火格子から排出される冷却水の温度、各火格子上の灰の温度などについても、そのレベルは低下し、又、火格子上の火炎の範囲に対応する輝度が変化するので、これらの測定値を用いて主燃焼完了点を検知することができる。
【００３２】
図３は本発明の火格子式廃棄物焼却炉の構成に係る実施の形態の他のを示す図である。図３において、図１と同じ構成の部分については、同一の符号を付し説明を省略する。この実施の形態においては、火格子１４が、水冷火格子１４ａ、冷却水量調節可能な水冷火格子１４ｄ、空冷火格子１４ｃの３種類からなり、火格子の配置が、水冷火格子１４ａを備えた水冷区域Ａと、冷却水量調節可能な水冷火格子１４ｄを備えた水量調節水冷区域Ｄと、空冷火格子１４ｃを備えた空冷区域Ｃに区分されて配置されている。水量調節水冷区域Ｄは主燃焼完了点の移動範囲を含む範囲に設けられている。この主燃焼完了点の移動範囲を含む範囲を、従来の火格子式焼却炉における区分に当てはめると、燃焼火格子の区域の下流側の一部と後燃焼火格子の区域の上流側の一部に渡る範囲に相当する。
【００３３】
上記各火格子１４ａ、１４ｄ、１４ｃには、それぞれ燃焼用空気を供給するための風箱（図示せず）が設けられており、風箱に供給された燃焼用空気が各火格子から吹出して火格子上の廃棄物に燃焼用の酸素が供給されると共に、燃焼用空気により火格子が冷却されるようになっている。
【００３４】
又、上記各火格子１４ａ、１４ｄ、１４ｃは固定火格子と可動火格子が交互に配置された構成になっており、水冷区域Ａと水量調節水冷区域Ｄの火格子は水冷構造になっている。そして、水量調節水冷区域Ｄに配置されている各火格子は冷却水の供給量が調節されるようになっており、それぞれの火格子毎に冷却度合いが変えられるようになっている。
【００３５】
図４は冷却水調節水冷区域の火格子を適度に冷却する方法に係る一例を示す図である。図４において、図１と同じ構成の部分については、同一の符号を付し説明を省略する。この実施の形態においては、各火格子に接続された冷却水配管２２に、それぞれ流量調節装置２８が設けられている。
【００３６】
各固定火格子の温度計２５により測定された温度測定値の信号が主燃焼完了点検知装置２６と制御器２７へ送られる。主燃焼完了点検知装置２６では、各固定火格子の温度測定値に基づいて主燃焼完了点が存在する火格子が検知され、その火格子の位置を示す信号が制御器２７へ送られる。制御器２７では、主燃焼完了点の下流側に位置する各火格子の温度に基づいて、各火格子の温度が所定値（３００℃〜５００℃程度の範囲設定）になるように、各火格子に接続されている流量調節装置２８へ、流量設定値を変更する信号が発信される。
【００３７】
これにより、主燃焼完了点より下流側の火格子が冷却されると共に、その冷却が所定の温度までにとどめられる。このため、火格子上の灰の温度を、灰が無害化される領域に保つことができる。
【００３８】
【発明の効果】
以上述べた本発明においては、主燃焼完了点の移動範囲を含む範囲に、水冷と空冷の切替え可能な火格子を備えた水冷−空冷切替え区域、又は冷却水量調節可能な水冷火格子を備えた水量調節水冷区域を設け、主燃焼完了点の下流側の火格子を空冷火格子として機能させたり、あるいはそれらに供給する冷却水の供給量を調節することにより、火格子の温度を適切な範囲に保つことができる。このため、火格子が高温に曝されることによる損傷が発生せず、又、有害物質が除去された質の高い焼却灰を排出される。
【００３９】
又、熾燃焼時の灰が過度に冷却されることなく、適切な温度に維持することができるので、焼却灰の無害化処理が行われる。例えば、焼却灰を４００℃以上に維持することにより、ダイオキシン類が揮散して減少する。又、焼却灰を６００℃以上に維持することにより、鉛（Ｐｂ）が酸化して酸化物（ＰｂＯ、ＰｂＯ_２　）になる反応が進行し、焼却灰からの鉛の溶出が抑制される。
【図面の簡単な説明】
【図１】本発明の火格子式廃棄物焼却炉の構成に係る実施の形態の一例を示す図である。
【図２】水冷−空冷切替え区域の火格子を適度に冷却する方法に係る一例を示す図である。
【図３】本発明の火格子式廃棄物焼却炉の構成に係る実施の形態の他の例を示す図である。
【図４】冷却水調節水冷区域の火格子を適度に冷却する方法に係る一例を示す図である。
【符号の説明】
１０　火格子式焼却炉
１１　主燃焼室
１２　廃棄物ホッパー
１３　廃棄物装入装置
１４　火格子
１４ａ　水冷火格子
１４ｂ　水冷と空冷の切替え可能な火格子
１４ｃ　空冷火格子
１４ｄ　冷却水量調節可能な水冷火格子
１５　焼却灰排出シュート
２０　固定火格子
２１　可動火格子
２２　冷却水配管
２３　流量遮断弁
２４　熱電対
２５　温度計
２６　主燃焼完了点検知装置
２７　制御器
２８　流量調節装置
４０　廃棄物
Ａ　水冷区域
Ｂ　水冷−空冷切替え区域
Ｃ　空冷区域
Ｄ　水量調節水冷区域[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a grate type waste incinerator provided with a water-cooled grate and an air-cooled grate.
[0002]
[Prior art]
In a grate-type waste incinerator that incinerates municipal solid waste, the grate is arranged in such a way that a fixed grate fixed in place and a movable grate that reciprocates partially overlap with each other. I have. For this reason, the waste loaded on the grate goes from the upstream side where the waste is loaded to the outlet side (downstream side) where it is converted into incinerated ash with the reciprocating motion of the movable grate. To move.
[0003]
When the waste is incinerated by such a grate incinerator, the waste loaded on the grate from the waste hopper is dried and thermally decomposed, and a dry region and combustion that generates a flame are performed. After passing through the main combustion area and the combustion area after the intense combustion, the combustion is completed, and is discharged as incinerated ash.
[0004]
In such a grate-type incinerator, the grate is cooled by combustion air blown from a wind box provided therebelow to impart heat resistance (air-cooled grate). However, in particular, there is an incinerator having a water-cooled structure in order to prevent damage due to high heat, particularly for the grate in the combustion area.
[0005]
In an incinerator equipped with a water-cooled grate, in general, the dry grate and the combustion grate have a water-cooled structure among the grate group divided into a dry grate, a combustion grate, and a post-combustion grate. ing.
[0006]
[Problems to be solved by the invention]
However, a material having a very high calorific value, such as plastic, is supplied, or a material having a low calorific value having a large proportion of inorganic substances is supplied. Further, the wastes to be input include those having good flammability and those having poor flammability. The above-mentioned fluctuations relating to the properties of the input waste also occur due to seasonal changes.
[0007]
For this reason, the place where the combustion of the waste producing the flame (main combustion) is completed (hereinafter referred to as the main combustion completion point) always exists at the downstream end of the combustion grate configured in the water-cooled structure. Move, not be. The movement of the main combustion completion point causes the following problem.
[0008]
For example, when the burning speed of the waste is high, the main combustion completion point is located upstream (the waste input side) of the downstream end of the combustion grate. As a result, the incinerated ash present on the combustion grate downstream of the main combustion completion point is excessively cooled, and the unburned portion is not sufficiently burned. In addition, since the temperature of the incinerated ash decreases, dioxins are not volatilized, and the detoxification of the incinerated ash becomes insufficient, and the quality of the incinerated ash deteriorates.
[0009]
In addition, when the burning rate of the waste is low, the main combustion completion point is lower than the downstream end of the combustion grate, that is, above the air-cooled post-combustion grate. At this time, on the upstream side of the post-combustion grate, since the main combustion not expected at the time of design is performed, the grate in that portion is exposed to high temperatures and damaged.
[0010]
An object of the present invention is to solve the above-mentioned problems and to provide a grate-type waste incinerator in which the grate is not damaged and the quality of incineration ash can be enhanced by removing harmful substances. .
[0011]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a grate-type waste incinerator provided with a water-cooled grate and an air-cooled grate, a water-cooled grate, a grate that can be switched between water-cooled and air-cooled. Has three types of grate consisting of an air-cooled grate, the arrangement of the grate is a water-cooled area with a water-cooled grate, and a water-cooled / air-cooled switching area with a grate that can be switched between water-cooled and air-cooled, It is characterized by being divided into an air-cooled area with an air-cooled grate.
[0012]
A second aspect of the present invention is characterized in that, in the first aspect of the present invention, the water cooling / air cooling switching area is provided in a range including a movement range of the main combustion completion point.
[0013]
According to a third aspect of the present invention, in the second aspect of the invention, the grate of the water-cooled / air-cooled switching area follows the movement of the main combustion completion point and is located upstream of the main combustion completion point. The grate functions as a water-cooled grate, and a grate located downstream of the main combustion completion point is configured to function as an air-cooled grate.
[0014]
According to a fourth aspect of the present invention, there is provided a grate type waste incinerator having a water-cooled grate and an air-cooled grate, wherein three types of fires comprising a water-cooled grate, a water-cooled grate having an adjustable cooling water amount, and an air-cooled grate. It has a grate and the arrangement of the grate is divided into a water-cooled area with a water-cooled grate, a water-regulated water-cooled area with a water-cooled grate with an adjustable cooling water rate, and an air-cooled area with an air-cooled grate. At the same time, the water volume adjustment water cooling area is provided in a range including the movement range of the main combustion completion point, and the amount of cooling water supplied to the grate located downstream of the main combustion completion point is equal to the temperature provided in the grate. The temperature of the grate is adjusted so as to be within a predetermined range based on a measurement value of a meter.
[0015]
According to a fifth aspect of the present invention, in the second or third aspect, a thermometer provided at each grate in the water-cooled / air-cooled switching area, the temperature of the cooling water discharged from each grate is measured. A thermometer for measuring, a device for measuring the range of the flame on the grate such as a luminance meter, and a measuring device for measuring the temperature of ash on each grate such as a radiation thermometer And a main combustion completion point detecting means for detecting a grate where a main combustion completion point exists based on a measurement value measured by any one of the measurement devices.
[0016]
The invention according to claim 6 is the invention according to claim 4, wherein a thermometer provided on each grate of the water volume adjustment water cooling area, a thermometer for measuring a temperature of cooling water discharged from each grate, A device for measuring the range of the flame on the grate such as a luminance meter, and a measuring device for measuring the temperature of ash on each grate such as a radiation thermometer; A main combustion completion point detecting means for detecting a grate where a main combustion completion point is present based on a measurement value measured by the measurement device is provided.
[0017]
In the present invention, a water-cooling / air-cooling switching area having a grate capable of switching between water cooling and air cooling is provided in a range including a moving range of the main combustion completion point (an area extending before and after the main combustion completion point), Further, a main combustion completion point detecting means is provided so that a grate where the main combustion completion point exists can be detected.
[0018]
For this reason, the grate in the water / air cooling switching area is switched from water cooling to air cooling or from air cooling to water cooling depending on the situation, and the incinerated ash on the grate is overcooled or the grate is overheated and damaged. Problems no longer occur. That is, when the main combustion completion point moves, cooling water is supplied to the grate located upstream of the grate where the main combustion completion point exists to function as a water-cooled grate, and the main combustion completion point becomes The supply of cooling water to the grate located downstream of the existing grate can be stopped, and the grate can function as an air-cooled grate.
[0019]
In addition, in the present invention, a water volume adjusting water cooling area having a water cooling grate capable of adjusting the cooling water amount is provided before and after the main combustion completion point, and the water supply to each grate located downstream of the main combustion completion point is provided. The amount of cooling water to be adjusted is adjusted so that the temperature of each grate becomes a predetermined value based on the measurement value of a thermometer provided for each grate. For this reason, the grate located downstream of the main combustion completion point is appropriately cooled, and the temperature is maintained in an appropriate range.
[0020]
Among the grate in the water cooling / air cooling switching area or the water volume adjustment water cooling area, the grate located downstream of the main combustion completion point is switched between water cooling / air cooling or the amount of cooling water is adjusted. The temperature is adjusted so as to be in the range of 200 ° C to 500 ° C. By maintaining the grate temperature at a high temperature, the temperature of the incinerated ash on the grate can be maintained at a high temperature.
[0021]
As described above, in the present invention, the position of the moving main combustion completion point is detected, and the grate on the upstream side of the main combustion completion point among the grate of the water cooling / air cooling switching area or the water volume adjustment water cooling area is detected. Since it functions as a water-cooled grate, damage due to high temperatures can be prevented as in the case of a grate in a water-cooled area.
[0022]
Also, by detecting the position of the moving main combustion completion point and making the main combustion completion point and the grate downstream thereof function as an air-cooled grate, or by adjusting the amount of cooling water supplied to them. Since the incinerated ash at the time of intense combustion can be maintained at an appropriate temperature without being excessively cooled, the incineration ash is rendered harmless downstream of the main combustion completion point. For example, when the incinerated ash is maintained at 400 ° C. or higher, dioxins volatilize and decrease. In addition, by maintaining the incinerated ash at 600 ° C. or higher, the reaction of oxidizing lead (Pb) to form oxides (PbO, PbO ₂ ) progresses, and the elution of lead from the incinerated ash is suppressed.
[0023]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing an example of an embodiment according to a configuration of a grate-type waste incinerator of the present invention. In FIG. 1, 10 is a grate incinerator, 11 is a main combustion chamber, and 16 is a secondary combustion chamber. Reference numeral 12 denotes a waste hopper, reference numeral 13 denotes a waste charging device, reference numeral 14 denotes a grate, and reference numeral 15 denotes an incineration ash discharge chute for discharging incineration ash 41. Numeral 40 indicates waste.
[0024]
The grate 14 is composed of a water-cooled grate 14a, a grate 14b that can be switched between water-cooled and air-cooled, and an air-cooled grate 14c. The arrangement on the grate is a water-cooled area A having a water-cooled grate 14a, It is divided into a water-cooled / air-cooled switching area B provided with a grate 14b capable of switching between water cooling and air cooling, and an air-cooled area C provided with an air-cooled grate 14c. The water-cooled / air-cooled switching area B is provided in a range including a moving range of the main combustion completion point. When the range including the movement range of the main combustion completion point is applied to the division in the conventional grate incinerator, a part on the downstream side of the area of the combustion grate and a part on the upstream side of the area of the post-combustion grate are included. Corresponding to the range.
[0025]
Each of the grate 14a, 14b, 14c is provided with a wind box (not shown) for supplying combustion air, and the combustion air supplied to the wind box blows out from each grate. Oxygen for combustion is supplied to the waste on the grate, and the grate is cooled by the combustion air.
[0026]
In addition, each of the grate 14a, 14b, 14c has a configuration in which fixed grate and movable grate are alternately arranged, and the grate in the water cooling area A, the water cooling, and the water cooling / air cooling switching area B has a water cooling structure. Has become. The grate arranged in the water-cooled / air-cooled switching area B functions as a water-cooled grate when the cooling water is supplied, and functions as an air-cooled grate when the supply of the cooling water is stopped. I have.
[0027]
FIG. 2 is a diagram illustrating an example of a method for appropriately cooling a grate in a water-cooled / air-cooled switching area. This figure shows a part of the grate in the water-cooled switching area, where 20 is a fixed grate and 21 is a movable grate. The grate 20 arranged in the water-cooled / air-cooled switching area has a hollow structure, and is provided with a flow path for flowing cooling water. A cooling water pipe 22 connected to each grate is provided with a flow shutoff valve 23. Each fixed grate 20 is provided with a thermometer 25 to which a thermocouple 24 is attached as a temperature sensor, so that the temperature of each grate can be continuously measured.
[0028]
In the grate of the water-cooled / air-cooled switching area configured as described above, the signal of the temperature measurement value measured by the thermometer 25 provided on each fixed grate 20 is sent to the main combustion completion point detecting device 26. The main combustion completion point detecting device 26 detects a grate where the main combustion completion point exists, based on the temperature measurement values measured by each thermometer 25. Next, a signal indicating the position of the grate where the main combustion completion point exists is sent from the main combustion completion point detecting device 26 to the controller 27, and the controller 27 checks the flow rate of the cooling water pipe connected to each grate. A signal to open the valve or a signal to close the valve is transmitted to the shutoff valve 23.
[0029]
With this, if there is a grate to which cooling water has not been supplied among the grate upstream of the main combustion completion point, the supply of cooling water to the grate is started, and the grate is cooled by water. Used as a grate. If there is a grate to which cooling water has been supplied from among the grate downstream of the main combustion completion point, the cooling water supplied to that grate is stopped, and the grate is cooled by air. Used as a grate. Thus, in the water-cooled / air-cooled switching area, the grate is appropriately switched from water-cooled to air-cooled or air-cooled to water-cooled each time the main combustion completion point moves, so that the grate is always appropriately cooled.
[0030]
The detection of the main combustion completion point is performed as follows. When the main combustion of the waste on the grate is completed and the combustion proceeds to the intense combustion, the temperature of the grate at that point drops because the temperature of the ash decreases. For this reason, it is determined that the main combustion has been completed on the grate one stage upstream of the grate whose temperature has dropped.
[0031]
In FIG. 2, the method of detecting the main combustion completion point using the measurement value of the thermometer provided on each grate has been described. However, the method for detecting the main combustion completion point is based on the temperature of the grate. However, the present invention is not limited to this. For example, at the point where main combustion is completed, the level of not only the temperature of the grate but also the temperature of the cooling water discharged from each grate, the temperature of the ash on each grate, etc., decreases, and Since the luminance corresponding to the range of the flame on the grate changes, the main combustion completion point can be detected using these measured values.
[0032]
FIG. 3 is a diagram showing another embodiment of the configuration of the grate-type waste incinerator of the present invention. 3, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, the grate 14 is composed of three types: a water-cooled grate 14a, a water-cooled grate 14d with an adjustable cooling water amount, and an air-cooled grate 14c, and the grate is provided with a water-cooled grate 14a. A water cooling section A, a water volume control water cooling section D provided with a water cooling grate 14d capable of controlling the amount of cooling water, and an air cooling section C provided with an air cooling grate 14c are provided separately. The water volume adjustment water cooling zone D is provided in a range including a movement range of the main combustion completion point. When the range including the movement range of the main combustion completion point is applied to the division in the conventional grate incinerator, a part on the downstream side of the area of the combustion grate and a part on the upstream side of the area of the post-combustion grate are included. Corresponding to the range.
[0033]
Each of the grate 14a, 14d, 14c is provided with a wind box (not shown) for supplying combustion air, and the combustion air supplied to the wind box blows out from each grate. Oxygen for combustion is supplied to the waste on the grate, and the grate is cooled by the combustion air.
[0034]
Each of the grate 14a, 14d, 14c has a configuration in which fixed grate and movable grate are alternately arranged, and the grate in the water cooling zone A and the water volume adjustment water cooling zone D has a water cooling structure. . The amount of cooling water supplied to each grate arranged in the water volume adjusting water cooling area D is adjusted, and the degree of cooling can be changed for each grate.
[0035]
FIG. 4 is a diagram showing an example of a method for appropriately cooling a grate in a cooling water conditioning water cooling area. 4, the same components as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted. In this embodiment, a cooling water pipe 22 connected to each grate is provided with a flow control device 28.
[0036]
The signal of the temperature measurement value measured by the thermometer 25 of each fixed grate is sent to the main combustion completion point detecting device 26 and the controller 27. The main combustion completion point detecting device 26 detects the grate where the main combustion completion point exists based on the temperature measurement value of each fixed grate, and sends a signal indicating the position of the grate to the controller 27. The controller 27 sets each fire on the basis of the temperature of each fire grate located downstream of the main combustion completion point so that the temperature of each fire grate becomes a predetermined value (a range of about 300 ° C. to 500 ° C.). A signal is sent to a flow controller 28 connected to the grid to change the flow setpoint.
[0037]
As a result, the grate downstream of the main combustion completion point is cooled, and the cooling is kept at a predetermined temperature. For this reason, the temperature of the ash on the grate can be maintained in a region where the ash is rendered harmless.
[0038]
【The invention's effect】
In the present invention described above, in a range including the movement range of the main combustion completion point, a water-cooled / air-cooled switching area having a grate capable of switching between water cooling and air cooling, or a water-cooled grate capable of adjusting the amount of cooling water is provided. A water volume control water cooling zone is provided, and the grate temperature can be adjusted to an appropriate range by making the grate downstream of the main combustion completion point function as an air-cooled grate, or adjusting the amount of cooling water supplied to them. Can be kept. Therefore, damage due to exposure of the grate to high temperatures does not occur, and high-quality incinerated ash from which harmful substances have been removed is discharged.
[0039]
Further, since the ash during the intense combustion can be maintained at an appropriate temperature without being excessively cooled, the incineration ash is rendered harmless. For example, by maintaining incinerated ash at 400 ° C. or higher, dioxins are volatilized and reduced. Further, by maintaining the incinerated ash at 600 ° C. or higher, a reaction in which lead (Pb) is oxidized into oxides (PbO, PbO ₂ ) progresses, and the elution of lead from the incinerated ash is suppressed.
[Brief description of the drawings]
FIG. 1 is a diagram showing an example of an embodiment according to a configuration of a grate-type waste incinerator of the present invention.
FIG. 2 is a diagram illustrating an example of a method for appropriately cooling a grate in a water-cooled / air-cooled switching area.
FIG. 3 is a diagram showing another example of the embodiment according to the configuration of the grate-type waste incinerator of the present invention.
FIG. 4 is a diagram illustrating an example of a method for appropriately cooling a grate in a cooling water conditioning water cooling area.
[Explanation of symbols]
Reference Signs List 10 grate incinerator 11 main combustion chamber 12 waste hopper 13 waste charging device 14 grate 14a water-cooled grate 14b grate switchable between water cooling and air cooling 14c air-cooled grate 14d water-cooled grate with adjustable cooling water volume 15 Incineration ash discharge chute 20 Fixed grate 21 Movable grate 22 Cooling water pipe 23 Flow cutoff valve 24 Thermocouple 25 Thermometer 26 Main combustion completion point detection device 27 Controller 28 Flow control device 40 Waste A Water cooling area B Water cooling Air cooling switching area C Air cooling area D Water volume adjustment water cooling area

Claims

A grate-type waste incinerator equipped with a water-cooled grate and an air-cooled grate has three types of grate: a water-cooled grate, a grate that can be switched between water-cooled and air-cooled, and an air-cooled grate. The arrangement is divided into a water-cooled area with a water-cooled grate, a water-cooled / air-cooled switchable area with a grate that can be switched between water-cooled and air-cooled, and an air-cooled area with an air-cooled grate. Grate type waste incinerator.

The grate type waste incinerator according to claim 1, wherein the water cooling / air cooling switching area is provided in a range including a movement range of the main combustion completion point.

The grate in the water-cooled / air-cooled switching area follows the movement of the main combustion completion point, and the grate located upstream of the main combustion completion point functions as a water-cooled grate, and is located downstream of the main combustion completion point. The grate-type waste incinerator according to claim 2, wherein the located grate is configured to function as an air-cooled grate.

A grate type waste incinerator equipped with a water-cooled grate and an air-cooled grate. The grate has three types of grate: a water-cooled grate, a water-cooled grate with an adjustable cooling water volume, and an air-cooled grate. Are divided into a water-cooled area with a water-cooled grate, a water-controlled water-cooled area with a water-cooled grate with an adjustable cooling water rate, and an air-cooled area with an air-cooled grate. The amount of cooling water to be supplied to the grate located downstream of the main combustion completion point is provided based on a measurement value of a thermometer provided on the grate. A grate-type waste incinerator, characterized in that the temperature of the grate is adjusted to be within a predetermined range.

A device for measuring the range of the flame on the grate, such as a thermometer provided for each grate in the water-cooled / air-cooled switching area, a thermometer for measuring the temperature of the cooling water discharged from each grate, and a luminance meter; A device for measuring the temperature of ash on each grate, such as a radiation thermometer, is provided, and a main combustion completion point exists based on the measurement value measured by any of the measuring devices. The grate type waste incinerator according to claim 2 or 3, further comprising a main combustion completion point detecting means for detecting a grate to be fired.

A thermometer provided for each grate in the water volume control water cooling area, a thermometer for measuring the temperature of the cooling water discharged from each grate, a device for measuring the range of the flame on the grate such as a luminance meter, radiation A device for measuring the temperature of the ash on each grate such as a thermometer is provided, and a main combustion completion point is present based on a measurement value measured by any of the measuring devices. The grate-type waste incinerator according to claim 4, further comprising a main combustion completion point detecting means for detecting a grate.