JP6103957B2

JP6103957B2 - Exhaust gas treatment equipment

Info

Publication number: JP6103957B2
Application number: JP2013011575A
Authority: JP
Inventors: 田中　徹; 徹田中; 宜之松本; 政徳國木
Original assignee: Hitachi Zosen Corp
Current assignee: Hitachi Zosen Corp
Priority date: 2013-01-25
Filing date: 2013-01-25
Publication date: 2017-03-29
Anticipated expiration: 2033-01-25
Also published as: JP2014140824A; CN103962003B; CN103962003A

Description

本発明は、排ガス処理設備に関する。 The present invention relates to an exhaust gas treatment facility .

排ガス処理ラインに、排ガス中にアンモニアガスを吹き込んで脱硝触媒に接触させ、脱硝する触媒反応塔を設置する触媒脱硝方式がある。この場合、触媒反応塔内の触媒や、触媒反応塔の下流側に設置された熱交換器の伝熱管に、硫酸のアンモニウム塩である硫酸アンモニウム［硫安、(NH₄)₂SO₄］や硫酸水素アンモニウム［酸性硫安、NH₄HSO₄］が析出して堆積し、脱硝効率や伝熱効率を低下させることが知られている。 In the exhaust gas treatment line, there is a catalyst denitration system in which ammonia reaction gas is blown into exhaust gas and brought into contact with a denitration catalyst to install a catalytic reaction tower for denitration. In this case, ammonium sulfate [ammonium sulfate, (NH ₄ ) ₂ SO ₄ ] or hydrogen sulfate is added to the catalyst in the catalytic reaction tower or the heat transfer tube of the heat exchanger installed downstream of the catalytic reaction tower. It is known that ammonium [acid ammonium sulfate, NH ₄ HSO ₄ ] precipitates and accumulates, thereby reducing the denitration efficiency and the heat transfer efficiency.

一般的な排ガス処理ラインは、排ガスを冷却塔で冷却後に、中和用および／または吸着用の薬剤を吹き込んでバグフィルタに導入し、バグフィルタにより煤塵や塩類およびダイオキシン、重金属などの吸着物を捕集し除去する。さらに排ガス中にアンモニアガスなどの還元用薬剤を吹き込み、触媒反応塔に導入して、排ガスから窒素酸化物を除去した後、煙突から排出する。 In a general exhaust gas treatment line, after exhaust gas is cooled by a cooling tower, neutralizing and / or adsorption chemicals are blown into the bag filter, and adsorbed materials such as dust, salts, dioxins and heavy metals are removed by the bag filter. Collect and remove. Further, a reducing agent such as ammonia gas is blown into the exhaust gas, introduced into the catalytic reaction tower, nitrogen oxides are removed from the exhaust gas, and then discharged from the chimney.

ところで、炉の運転中に、触媒反応塔の触媒に析出、堆積した硫酸のアンモニウム塩を除去するものとして、たとえば特許文献１がある。特許文献１の排ガス処理ラインでは、触媒反応塔を複数の反応部に分割しておき、硫酸のアンモニウム塩が析出、堆積して反応効率が低下すると、反応部の一部への排ガスの導入を停止し、この反応部にのみ熱分解温度まで加熱した排ガスを導入して硫酸のアンモニウム塩を熱分解する。そして、熱分解成分を含む排ガスを、冷却塔の入口で排ガスに合流してバグフィルタに送り出すものである。 By the way, Patent Document 1 discloses an example of removing the ammonium salt of sulfuric acid deposited and deposited on the catalyst of the catalytic reaction tower during the operation of the furnace. In the exhaust gas treatment line of Patent Document 1, the catalytic reaction tower is divided into a plurality of reaction parts, and when ammonium salt of sulfuric acid is deposited and deposited to reduce the reaction efficiency, the exhaust gas is introduced into a part of the reaction part. The exhaust gas heated to the thermal decomposition temperature is introduced only into the reaction section to thermally decompose the ammonium salt of sulfuric acid. And the exhaust gas containing a thermal decomposition component joins exhaust gas at the inlet of a cooling tower, and sends it out to a bag filter.

特開平１０−１９２６５７JP-A-10-192657

しかしながら、バグフィルタに導入する排ガス温度は１６０℃前後であり、硫酸のアンモニウム塩の熱分解温度は３００℃前後であるため、１６０℃から３００℃に加熱する熱エネルギが大きいこと、また触媒に析出、堆積した硫酸のアンモニウム塩の熱分解に十分な時間を要すること、触媒反応塔が複数の反応部に分割されるために、構造や配管が複雑になり、設備コストがかかること、などの問題があった。 However, the exhaust gas temperature introduced into the bag filter is around 160 ° C., and the thermal decomposition temperature of the ammonium salt of sulfuric acid is around 300 ° C., so that the heat energy heated from 160 ° C. to 300 ° C. is large, and the catalyst is deposited on the catalyst. Problems such as the time required for the thermal decomposition of the deposited ammonium salt of sulfuric acid, and the fact that the catalytic reaction tower is divided into a plurality of reaction parts makes the structure and piping complicated and the equipment costs high. was there.

本発明は上記問題点を解決して、エネルギコストも少なく、設備コストも低減できる排ガス処理設備を提供することを目的とする。 An object of the present invention is to solve the above-mentioned problems and to provide an exhaust gas treatment facility that can reduce energy costs and equipment costs.

本発明は、炉から排出される排ガスの排ガス処理ラインの上流側から、塩類、吸着物および煤塵を捕集するバグフィルタと、熱交換器と、排ガスから窒素酸化物を除去する触媒反応塔とを具備した排ガス処理設備であって、
前記熱交換器は、前記バグフィルタから前記触媒反応塔に導入される排ガスが加熱される被加熱側と、前記触媒反応塔から排出された排ガスにより、前記触媒反応塔に導入される排ガスを加熱する加熱側と、を有し、
前記バグフィルタから排出された排ガスを大気側に排出するバイパス排気ラインを設け、
循環加熱ガスの循環方向に、循環送風機と、循環ガス加熱器と、前記触媒反応塔と、前記熱交換器の加熱側と、を具備するとともに、前記循環ガス加熱器から前記触媒反応塔をバイパスして前記熱交換器の加熱側に接続される第１バイパス流路部を有するガス循環ラインを設け、
前記ガス循環ラインにおいて、
前記第１バイパス流路部を閉じ、前記循環ガス加熱器により加熱した循環加熱ガスにより、前記触媒反応塔と前記熱交換器の加熱側にそれぞれ堆積した硫酸のアンモニウム塩を分解することと、
前記第１バイパス流路部を開けるとともに前記第１バイパス流路部の分岐部から前記触媒反応塔に至る前記ガス循環ラインを閉じ、前記循環ガス加熱器により加熱した循環加熱ガスにより、前記熱交換器の加熱側に堆積した硫酸のアンモニウム塩を分解すること、とを選択的に行うことを特徴とする。 The present invention includes a bag filter that collects salts, adsorbate, and soot and dust from an upstream side of an exhaust gas treatment line of exhaust gas discharged from a furnace, a heat exchanger, and a catalytic reaction tower that removes nitrogen oxides from the exhaust gas. An exhaust gas treatment facility comprising:
The heat exchanger heats the exhaust gas introduced into the catalytic reaction tower by the heated side where the exhaust gas introduced from the bag filter into the catalytic reaction tower is heated and the exhaust gas discharged from the catalytic reaction tower. And a heating side to
Provide a bypass exhaust line for exhausting the exhaust gas discharged from the bag filter to the atmosphere side,
A circulation fan, a circulation gas heater, the catalyst reaction tower, and a heating side of the heat exchanger are provided in a circulation direction of the circulation heating gas, and the catalyst reaction tower is bypassed from the circulation gas heater. And providing a gas circulation line having a first bypass flow path connected to the heating side of the heat exchanger ,
In the gas circulation line,
Decomposing ammonium salt of sulfuric acid deposited on the heating side of the catalytic reaction tower and the heat exchanger, respectively , with the circulating heating gas heated by the circulating gas heater , closing the first bypass flow path portion ;
Opening the first bypass flow path and closing the gas circulation line from the branch of the first bypass flow path to the catalytic reaction tower, and the heat exchange with the circulating heating gas heated by the circulating gas heater And decomposing the ammonium salt of sulfuric acid deposited on the heating side of the vessel .

また請求項１記載の構成において、第１バイパス流路部を開閉する第１６切換弁と、
ガス循環ラインで前記第１バイパス流路部の分岐部から前記触媒反応塔の間に介在された第１２切替弁と、を設けたものである。 Further, in the configuration of claim 1, a sixteenth switching valve for opening and closing the first bypass flow path section;
And a twelfth switching valve interposed between the branch portion of the first bypass flow path portion and the catalytic reaction tower in the gas circulation line.

さらに請求項１または２記載の構成において、前記ガス循環ラインの循環加熱ガスの一部を、前記バグフィルタの入口に導出する循環ガス排気流路部を設け、
循環加熱ガスの一部を排出する時に、前記ガス循環ラインに外気を導入する補充用外気導入流路部を設け、
前記循環ガス排気流路部から排出された循環加熱ガスの熱分解成分を、前記バグフィルタにより捕集し、前記バイパス排気ラインから排出するものである。 Furthermore, in the configuration according to claim 1 or 2 , a circulation gas exhaust passage section for leading a part of the circulating heating gas of the gas circulation line to an inlet of the bag filter is provided.
When exhausting a part of the circulating heating gas, a replenishment outside air introduction flow path section for introducing outside air into the gas circulation line is provided,
The pyrolysis component of the circulating heating gas discharged from the circulating gas exhaust passage is collected by the bag filter and discharged from the bypass exhaust line.

さらにまた請求項３記載の構成において、循環ガス排気流路部に、循環加熱ガスに外気を混合して冷却する冷却用外気導入流路部を設け、
炉の停止中に循環ガス排気流路部から排出される循環加熱ガスに、冷却用外気導入流路部から外気を混合して冷却し、バグフィルタに導入するものである。 Furthermore, in the configuration according to claim 3, the circulating gas exhaust channel portion is provided with a cooling outside air introduction channel portion that mixes and cools the outside air to the circulating heating gas,
The circulating heated gas discharged from the circulating gas exhaust flow path while the furnace is stopped is mixed with the external air from the cooling external air introducing flow path, cooled, and introduced into the bag filter.

また請求項３記載の構成において、ガス循環ラインで循環加熱ガスの温度を検出する循環ガス温度検出器と、
バグフィルタ出口の排ガス温度を検出する排ガス温度検出器と、
バイパス排気ラインから外部に排出される排ガス中のアンモニアガスおよび／または硫黄酸化物の濃度を検出する排ガス成分検出器と、
循環ガス排気流路部に設けられた循環ガス排出弁と、
前記補充用外気導入流路部に設けられた補充用外気導入弁と、
前記循環ガス排出弁および前記補充用外気導入弁の開度を制御する熱分解用コントローラと、を具備し、
前記熱分解用コントローラは、炉の運転中に、前記循環ガス温度検出器の検出値に基づいて、循環加熱ガスの温度を制御するとともに、前記排ガス温度検出器および前記排ガス成分検出器の検出値に基づいて、前記循環ガス排出弁と前記補充用外気導入弁の開度を制御するものである。 Further, in the configuration of claim 3, a circulating gas temperature detector for detecting the temperature of the circulating heating gas in the gas circulation line;
An exhaust gas temperature detector for detecting the exhaust gas temperature at the bag filter outlet;
An exhaust gas component detector for detecting the concentration of ammonia gas and / or sulfur oxide in the exhaust gas discharged from the bypass exhaust line;
A circulation gas discharge valve provided in the circulation gas exhaust passage,
A replenishment outside air introduction valve provided in the replenishment outside air introduction flow path section;
A thermal decomposition controller that controls the opening degree of the circulating gas discharge valve and the replenishment outside air introduction valve, and
The pyrolysis controller controls the temperature of the circulating heating gas based on the detected value of the circulating gas temperature detector during operation of the furnace, and the detected values of the exhaust gas temperature detector and the exhaust gas component detector. Based on the above, the opening degree of the circulating gas discharge valve and the supplementary outside air introduction valve is controlled.

さらに請求項５記載の構成において、冷却用外気導入流路部に設けられた冷却用外気導入弁を具備し、
熱分解用コントローラは、
炉の停止中に、循環加熱ガスの温度を、硫酸のアンモニウム塩を分解温度可能な適正温度範囲として所定時間保持し、前記触媒反応塔および／または前記熱交換器内に堆積した硫酸のアンモニウム塩を分解した後、前記循環ガス排出弁を開けて循環加熱ガスの一部を循環ガス排気流路部に導出するとともに、前記冷却用外気導入弁を開け、外気を前記循環ガス排気流路部に導入して循環加熱ガスを冷却し、循環加熱ガスと外気との混合ガスの温度をバグフィルタに適した範囲に制御するものである。 Furthermore, in the configuration according to claim 5, further comprising a cooling outside air introduction valve provided in the cooling outside air introduction flow path section,
The thermal decomposition controller
While the furnace is stopped, the temperature of the circulating heating gas is maintained within a proper temperature range in which the ammonium salt of sulfuric acid can be decomposed for a predetermined time, and the ammonium salt of sulfuric acid deposited in the catalytic reaction tower and / or the heat exchanger After opening the circulating gas discharge valve, a part of the circulating heating gas is led out to the circulating gas exhaust passage part, and the outside air introduction valve for cooling is opened, and the outside air is supplied to the circulating gas exhaust passage part. It introduces and cools circulating heating gas, and controls the temperature of the mixed gas of circulating heating gas and external air to the range suitable for a bag filter.

さらにまた請求項１記載の構成において、バグフィルタの予熱用に設置されたバグフィルタ予熱器およびバグフィルタ予熱送風機を、循環送風機および循環ガス加熱器としても使用できるように、ガス循環ラインに設置したものである。 Furthermore, in the configuration of claim 1, the bag filter preheater and the bag filter preheating blower installed for preheating the bag filter are installed in the gas circulation line so that they can be used as a circulation blower and a circulation gas heater. Is.

請求項１記載の発明によれば、バグフィルタから排出される排ガスを排出するバイパス排気ラインと、循環加熱ガスを硫酸のアンモニウム塩を熱分解可能な温度に加熱して触媒反応塔や熱交換器に循環させるガス循環ラインと、循環加熱ガスを、触媒反応塔をバイパスして熱交換器の加熱側にのみ送る第１バイパス流路部とを設けたので、炉の運転中に触媒反応塔と熱交換器の加熱側や、熱交換器の加熱側に、堆積した硫酸のアンモニウム塩を選択的に分解することができる。したがって、ガス循環ラインに沿って循環加熱ガスを加熱、循環させて繰り返し使用できるので、熱エネルギコストを削減することができるとともに、触媒反応塔、熱交換器内に堆積した硫酸のアンモニウム塩を良好に熱分解することができ、配管構造や触媒反応塔の構造を簡略化できて、設備コストを低減することができる。 According to the first aspect of the present invention, the bypass exhaust line for discharging the exhaust gas discharged from the bag filter, and the catalytic reaction tower and the heat exchanger by heating the circulating heating gas to a temperature capable of thermally decomposing ammonium salt of sulfuric acid. A gas circulation line that circulates to the heat exchanger, and a first bypass flow path section that sends the circulating heating gas to the heating side of the heat exchanger bypassing the catalytic reaction tower, The deposited ammonium salt of sulfuric acid can be selectively decomposed on the heating side of the heat exchanger or on the heating side of the heat exchanger . Therefore, since the circulating heating gas can be heated and circulated along the gas circulation line and used repeatedly, the heat energy cost can be reduced and the ammonium salt of sulfuric acid deposited in the catalytic reaction tower and heat exchanger is good. Therefore, the piping structure and the structure of the catalytic reaction tower can be simplified, and the equipment cost can be reduced.

請求項４記載の発明によれば、炉が停止中であっても、ガス循環ラインに循環加熱ガスを循環させ、触媒反応塔や熱交換器に堆積した硫酸のアンモニウム塩を熱分解することができる。そしてガス循環ラインから冷却用外気導入流路部を介してバグフィルタに導出する循環加熱ガスに、外気を混合して冷却することができるので、バグフィルタに適正温度の混合ガスを導入することができ、バグフィルタの焼損を防止することができる。 According to the invention described in claim 4 , even when the furnace is stopped, the circulating heating gas is circulated through the gas circulation line, and the ammonium salt of sulfuric acid deposited in the catalytic reaction tower or the heat exchanger can be thermally decomposed. it can. And since the outside air can be mixed and cooled with the circulating heating gas led out to the bag filter from the gas circulation line through the cooling outside air introduction flow path section, it is possible to introduce a mixed gas at an appropriate temperature into the bag filter. It is possible to prevent the bug filter from being burned out.

請求項５記載の発明によれば、熱分解用コントローラにより、循環加熱ガスの温度と、ガス循環ラインから導出される循環加熱ガスと排ガスの混合ガスの温度を制御することにより、硫酸のアンモニウム塩を効果的に熱分解できるとともに、排ガスの成分を良好に保つことができ、バグフィルタの熱損傷を防止することができる。 According to the invention described in claim 5, by controlling the temperature of the circulating heating gas and the temperature of the mixed gas of the circulating heating gas and the exhaust gas derived from the gas circulation line by the pyrolysis controller, the ammonium salt of sulfuric acid Can be effectively thermally decomposed, the components of the exhaust gas can be kept good, and thermal damage of the bag filter can be prevented.

請求項６記載の発明によれば、炉の停止中であっても、熱分解用コントローラにより、循環加熱ガスの温度を制御することにより、硫酸のアンモニウム塩を効果的に熱分解できる。またガス循環ラインから導出される循環加熱ガスに外気を混合して、その混合ガスを冷却することにより、循環加熱ガスに含まれる熱分解成分を固体化し、さらにバグフィルタに残る中和用や吸着用の薬剤により、中和や吸着させてバグフィルタで捕集することができるとともに、バグフィルタの焼損を防止することができる。 According to the sixth aspect of the present invention, even when the furnace is stopped, the ammonium salt of sulfuric acid can be effectively pyrolyzed by controlling the temperature of the circulating heating gas by the thermal decomposition controller. In addition, by mixing the outside air with the circulating heating gas derived from the gas circulation line and cooling the mixed gas, the pyrolysis component contained in the circulating heating gas is solidified and further neutralized or adsorbed on the bag filter. The chemicals for neutralization can be neutralized or adsorbed and collected by the bag filter, and the bag filter can be prevented from burning.

請求項７記載の発明によれば、予め設置された循環ガス送風機および循環ガス加熱器を利用することにより、既存の排ガス処理設備に容易に適用することができ、設備コストを低減することができる。 According to the seventh aspect of the present invention, by using a circulating gas blower and a circulating gas heater that are installed in advance, it can be easily applied to existing exhaust gas treatment equipment, and equipment costs can be reduced. .

本発明に係る排ガス処理設備の実施例１を示し、通常運転時の構成図である。FIG. 1 is a configuration diagram illustrating a first embodiment of an exhaust gas treatment facility according to the present invention during normal operation. 焼却炉の運転時に、硫酸のアンモニウム塩を熱分解する説明図である。It is explanatory drawing which thermally decomposes the ammonium salt of a sulfuric acid at the time of a driving | operation of an incinerator. 焼却炉の休止時に、硫酸のアンモニウム塩を熱分解する説明図である。It is explanatory drawing which thermally decomposes the ammonium salt of a sulfuric acid at the time of a rest of an incinerator. 本発明に係る排ガス処理設備の実施例２を示し、通常運転時の構成図である。Example 2 of the exhaust gas treatment facility according to the present invention is shown and is a configuration diagram during normal operation. 焼却炉の運転時に、硫酸のアンモニウム塩を熱分解する説明図である。It is explanatory drawing which thermally decomposes the ammonium salt of a sulfuric acid at the time of a driving | operation of an incinerator. 焼却炉の休止時に、硫酸のアンモニウム塩を熱分解する説明図である。It is explanatory drawing which thermally decomposes the ammonium salt of a sulfuric acid at the time of a rest of an incinerator.

［実施例１］
以下、本発明の実施例１を図１〜図３に基づいて説明する。
（基本構造）
この排ガス処理設備は、図１に示すように、たとえば廃棄物用の焼却炉（炉）１１からの下流側に、排ガスを熱回収するボイラ１２と、排ガスを冷却する冷却塔１３が設置されている。この冷却塔１３から下流側の排ガス処理ライン１０に、バグフィルタ１６、熱交換器（被加熱側）１７、ガス再加熱器１８、触媒反応塔２０、熱交換器（加熱側）１７、誘引通風機２１および煙突２２が順に設置されており、排ガスが順次導入されて処理される。 [Example 1]
Embodiment 1 of the present invention will be described below with reference to FIGS.
(Basic structure)
As shown in FIG. 1, in this exhaust gas treatment facility, for example, a boiler 12 for heat recovery of exhaust gas and a cooling tower 13 for cooling the exhaust gas are installed downstream from an incinerator (furnace) 11 for waste. Yes. A bag filter 16, a heat exchanger (heated side) 17, a gas reheater 18, a catalytic reaction tower 20, a heat exchanger (heating side) 17, an induced draft are sent to the exhaust gas treatment line 10 downstream from the cooling tower 13. The machine 21 and the chimney 22 are installed in order, and the exhaust gas is sequentially introduced and processed.

バグフィルタ１６は、排ガスに含まれる塩化水素やＳＯ_Ｘ、重金属、煤塵、ダイオキシンなどを捕集するもので、バグフィルタ１６の上流側に、重金属類やダイオキシンなどの有害物質を吸着するための活性炭を排ガス中に吹き込む活性炭供給装置１４と、排ガス中の塩化水素（ＨＣｌ）や硫黄酸化物（ＳＯ_Ｘ）などに反応させるために、消石灰など中和用のアルカリ性薬剤を排ガス中に吹き込む薬剤供給装置１５が設けられる。 The bag filter 16 collects hydrogen chloride, SO _x , heavy metals, dust, dioxins, etc. contained in the exhaust gas, and activated carbon for adsorbing harmful substances such as heavy metals and dioxins on the upstream side of the bag filter 16. Activated carbon supply device 14 that blows gas into the exhaust gas, and a drug supply device that blows neutralizing alkaline chemicals such as slaked lime into the exhaust gas in order to react with hydrogen chloride (HCl), sulfur oxide (SO _X ), etc. in the exhaust gas 15 is provided.

再加熱用の熱交換器１７とガス再加熱器１８は、下流側に設置された触媒反応塔２０に供給される排ガスを、最適な温度に加熱するためのものである。触媒反応塔２０では、アンモニア供給装置２３からアンモニアガスなどの還元用薬剤が排ガス中に噴射され、排ガスを脱硝触媒に接触させることで、ＮＯ_Ｘ（窒素酸化物）などを除去する。 The heat exchanger 17 for reheating and the gas reheater 18 are for heating the exhaust gas supplied to the catalytic reaction tower 20 installed on the downstream side to an optimum temperature. In the catalytic reaction tower 20, a reducing agent such as ammonia gas is injected into the exhaust gas from the ammonia supply device 23, and NO _X (nitrogen oxide) or the like is removed by bringing the exhaust gas into contact with the denitration catalyst.

上記構成において、触媒反応塔２０や熱交換器１７で、硫酸のアンモニウム塩である硫酸アンモニウム［硫安、(NH₄)₂SO₄］や硫酸水素アンモニウム［酸性硫安、NH₄HSO₄］が析出して堆積すると、脱硝効率や伝熱効率が低下するため、前記硫酸のアンモニウム塩を加熱分解して除去する作業を行うための機器および配管が設けられている。 In the above configuration, ammonium sulfate [ammonium sulfate, (NH ₄ ) ₂ SO ₄ ] and ammonium hydrogen sulfate [acidic ammonium sulfate, NH ₄ HSO ₄ ], which are ammonium salts of sulfuric acid, are deposited in the catalytic reaction tower 20 and the heat exchanger 17. When deposited, the denitration efficiency and the heat transfer efficiency are lowered, and therefore, equipment and piping for performing an operation of thermally decomposing and removing the ammonium salt of sulfuric acid are provided.

（バイパス排気ライン）
バグフィルタ１６と熱交換器１７の間の排ガス処理ライン１０からバイパス排気ライン３０が分岐され、このバイパス排気ライン３０の出口が誘引送風機２１の入口側に接続されている。そして、このバイパス排気ライン３０により、排ガスを、熱交換器１７、ガス再加熱器１８および触媒反応塔２０を通さずに、誘引送風機２１から煙突２２を介して大気中に排出することができる。 (Bypass exhaust line)
A bypass exhaust line 30 is branched from the exhaust gas treatment line 10 between the bag filter 16 and the heat exchanger 17, and an outlet of the bypass exhaust line 30 is connected to an inlet side of the induction blower 21. And by this bypass exhaust line 30, exhaust gas can be discharged | emitted in the atmosphere via the chimney 22 from the induction blower 21, without passing the heat exchanger 17, the gas reheater 18, and the catalytic reaction tower 20. FIG.

（ガス循環ライン）
図２に明瞭に示すように、ガス循環ライン３１には、上流側から順に、触媒反応塔２０、熱交換器（加熱側）１７、循環送風機３２、循環ガス加熱器３３が設置されている。このガス循環ライン３１は、排ガス処理ライン１０の一部を使用した共用流路部３１ａと、別途設けられる加熱流路部３１ｂとを具備している。共用流路部３１ａは、触媒反応塔２０から熱交換器（加熱側）１７の出口側までの排ガス処理ライン１０と共用した配管である。 (Gas circulation line)
As clearly shown in FIG. 2, in the gas circulation line 31, a catalytic reaction tower 20, a heat exchanger (heating side) 17, a circulation fan 32, and a circulation gas heater 33 are installed in this order from the upstream side. The gas circulation line 31 includes a shared flow path portion 31a using a part of the exhaust gas treatment line 10 and a heating flow path portion 31b provided separately. The common flow path portion 31 a is a pipe shared with the exhaust gas treatment line 10 from the catalytic reaction tower 20 to the outlet side of the heat exchanger (heating side) 17.

加熱流路部３１ｂは、共用流路部３１ａの出口側から、循環送風機３２および循環ガス加熱器３３を介して触媒反応塔２０の入口側に接続される配管をいう。またこの加熱流路部３１ｂに、バグフィルタ１６の入口に接続されてガス循環ライン３１の循環加熱ガスの一部を導出する循環ガス排気流路部３１ｃと、循環送風機３２の入口側に接続されて、ガス循環ライン３１に補充用の外気を導入する補充用外気導入流路部３１ｄと、循環ガス排気流路部３１ｃの出口側に接続されて循環加熱ガスに冷却用の外気を導入する冷却用外気導入流路部３１ｇが設けられている。 The heating flow path portion 31b is a pipe connected from the outlet side of the common flow path portion 31a to the inlet side of the catalytic reaction tower 20 via the circulation blower 32 and the circulation gas heater 33. In addition, the heating channel 31 b is connected to the inlet of the bag filter 16 and connected to the circulation gas exhaust channel 31 c that leads out part of the circulating heating gas of the gas circulation line 31 and the inlet side of the circulation fan 32. The replenishment outside air introduction flow path portion 31d for introducing replenishment outside air into the gas circulation line 31 and the cooling which is connected to the outlet side of the circulation gas exhaust flow passage portion 31c and introduces the cooling outside air to the circulating heating gas An outdoor air introduction flow path portion 31g is provided.

前記循環送風機３２は、ガス循環ライン３１に沿って循環加熱ガスを循環させるものである。また循環ガス加熱器３３は、循環加熱ガスを硫酸のアンモニウム塩の分解温度以上で、適正範囲である３２０℃〜４５０℃に加熱するものである。 The circulating blower 32 circulates the circulating heating gas along the gas circulation line 31. The circulating gas heater 33 heats the circulating heating gas to 320 ° C. to 450 ° C., which is an appropriate range, above the decomposition temperature of the ammonium salt of sulfuric acid.

加熱流路部３１ｂに、循環ガス加熱器３３と触媒反応塔２０の間のガス循環ライン３１から第１バイパス流路部３１ｅが分岐され、第１バイパス流路部３１ｅの出口が触媒反応塔２０と熱交換器（加熱側）１７の間の共用流路部３１ａに接続されている。この第１バイパス流路部３１ｅにより、循環ガス加熱器３３で加熱された循環加熱ガスを、触媒反応塔２０を通さずに、直接熱交換器１７に導入することができる。 A first bypass passage 31e is branched from the gas circulation line 31 between the circulation gas heater 33 and the catalytic reaction tower 20 to the heating passage 31b, and an outlet of the first bypass passage 31e is connected to the catalytic reaction tower 20. And the heat exchanger (heating side) 17 is connected to a common flow path portion 31a. By this first bypass flow path portion 31e, the circulating heating gas heated by the circulating gas heater 33 can be directly introduced into the heat exchanger 17 without passing through the catalytic reaction tower 20.

また、第１バイパス流路部３１ｅから第２バイパス流路部３１ｆが分岐され、第２バイパス流路部３１ｆの出口が循環ガス排気流路部３１ｃの上流側の加熱流路部３１ｂに接続されている。この第２バイパス流路部３１ｆにより、触媒反応塔２０から排出された循環加熱ガスを、熱交換器（加熱側）１７を通さずに、加熱流路部３１ｂに循環させることができる。 In addition, the second bypass channel portion 31f is branched from the first bypass channel portion 31e, and the outlet of the second bypass channel portion 31f is connected to the heating channel portion 31b on the upstream side of the circulating gas exhaust channel portion 31c. ing. By this second bypass flow path portion 31f, the circulating heated gas discharged from the catalytic reaction tower 20 can be circulated to the heating flow path portion 31b without passing through the heat exchanger (heating side) 17.

循環ガス加熱器３３の出口に、循環加熱ガスの温度を検出する循環ガス温度検出器Ｔ１が設置されている。またバグフィルタ１６の出口に、排ガスの温度を検出する排ガス温度検出器Ｔ２が設けられている。さらに誘引送風機２１の出口に、排ガスに含まれるアンモニアガス（ＮＨ_３）および／または硫黄酸化物（ＳＯ_Ｘ）の濃度を検出する排ガス成分検出器Ｍが設けられている。 A circulating gas temperature detector T <b> 1 that detects the temperature of the circulating heating gas is installed at the outlet of the circulating gas heater 33. An exhaust gas temperature detector T2 for detecting the temperature of the exhaust gas is provided at the outlet of the bag filter 16. Further, an exhaust gas component detector M for detecting the concentration of ammonia gas (NH ₃ ) and / or sulfur oxide (SO _X ) contained in the exhaust gas is provided at the outlet of the induction fan 21.

さらに、これら複数のライン１０，３０，３１と流路部３１ａ〜３１ｆを通過する排ガス、循環加熱ガスの流路を切替えるために、開閉および流量調整可能な複数の開閉器であるダンパ（以下、切換弁という）が設けられている。 Furthermore, in order to switch the exhaust gas passing through the plurality of lines 10, 30, 31 and the flow path portions 31a to 31f and the flow path of the circulating heating gas, dampers (hereinafter referred to as a plurality of switches that can be opened and closed and the flow rate of which can be adjusted). A switching valve).

まず、排ガス処理ライン１０（共用流路部３１ａを含む）に第１〜第７切換弁Ｖ１〜Ｖ７が設けられている。すなわち、排ガス処理ライン１０において、循環ガス排気流路部３１ｃの接続部で上流側に設けられた第１切替弁Ｖ１、バグフィルタ１６とバイパス排気ライン３０の分岐部の間に設けられた第２切換弁Ｖ２、バイパス排気ライン３０の分岐部と熱交換器（被加熱側）１７の間に設けられた第３切換弁Ｖ３、ガス再加熱器１８と加熱流路部３１ｂとの接続部の間に設けられた第４切換弁Ｖ４、触媒反応塔２０と第１バイパス流路部３１ｅの接続部の間に設けられた第５切換弁Ｖ５、第１バイパス流路部３１ｅの接続部と熱交換器（加熱側）１７の間に設けられた第６切換弁Ｖ６、および排ガス処理ライン１０における加熱流路部３１ｂとの分岐部とバイパス排気ライン３０の接続部の間に設けられた第７切換弁Ｖ７である。 First, the first to seventh switching valves V1 to V7 are provided in the exhaust gas treatment line 10 (including the common flow path portion 31a). That is, in the exhaust gas treatment line 10, the first switching valve V <b> 1 provided on the upstream side at the connection part of the circulating gas exhaust flow path part 31 c, the second provided between the branch part of the bag filter 16 and the bypass exhaust line 30. Between the switching valve V2, the branch portion of the bypass exhaust line 30 and the third switching valve V3 provided between the heat exchanger (heated side) 17 and the connection portion between the gas reheater 18 and the heating flow path portion 31b. Heat exchange with the fourth switching valve V4 provided in the second switching valve V5, the fifth switching valve V5 provided between the catalytic reaction tower 20 and the connection portion of the first bypass flow passage portion 31e, and the connection portion of the first bypass flow passage portion 31e. The sixth switching valve V6 provided between the heaters (heating side) 17 and the seventh switching valve provided between the branching portion of the exhaust gas treatment line 10 and the heating flow path portion 31b and the connection portion of the bypass exhaust line 30. Valve V7.

また、バイパス排気ライン３０には、排ガス処理ライン１０との分岐部近傍に第８切換弁Ｖ８が設けられ、この第８切換弁Ｖ８の下流側で排ガス処理ライン１０との接続部近傍に第９切換弁Ｖ９が設けられる。 Further, the bypass exhaust line 30 is provided with an eighth switching valve V8 in the vicinity of a branch portion with the exhaust gas treatment line 10, and a ninth portion near the connection portion with the exhaust gas treatment line 10 on the downstream side of the eighth switching valve V8. A switching valve V9 is provided.

共用流路部３１ａを除くガス循環ライン３１に、第１１切換弁Ｖ１１および第１２切換弁Ｖ１２が設けられる。すなわち、加熱流路部３１ｂにおいて、排ガス処理ライン１０からの分岐部と第２バイパス流路部３１ｆの接続部の間に設けられた第１１切換弁Ｖ１１と、第１バイパス流路部３１ｅの分岐部と触媒反応塔２０に接続される排ガス処理ライン１０の接続部の間に設けられた第１２切換弁Ｖ１２とが設けられる。 An eleventh switching valve V11 and a twelfth switching valve V12 are provided in the gas circulation line 31 excluding the common flow path portion 31a. That is, in the heating flow path part 31b, the 11th switching valve V11 provided between the branch part from the exhaust gas treatment line 10 and the connection part of the second bypass flow path part 31f and the first bypass flow path part 31e branch. And a twelfth switching valve V12 provided between the connecting portion of the exhaust gas treatment line 10 connected to the catalytic reaction tower 20.

また循環ガス排気流路部３１ｃに、加熱流路部３１ｂの分岐部と冷却用外気導入部３１ｇの接続部の間に第１３切換弁（循環ガス排出弁）Ｖ１３が設けられている。さらに、冷却用外気導入部３１ｇに第１４切換弁（冷却用外気導入弁）Ｖ１４が介設けられている。さらにまた、補充用外気導入部３１ｄに第１５切換弁（補充用外気導入弁）Ｖ１５が設けられている。また第１バイパス流路部３１ｅには、加熱流路部３１ｂの分岐部と第２バイパス流路部３１ｆの分岐部の間に第１６切換弁Ｖ１６が設けられている。さらに第２バイパス流路部３１ｆには、第１バイパス流路部３１ｅの分岐部近傍に第１７切換弁Ｖ１７が設けられている。 In addition, a thirteenth switching valve (circulation gas discharge valve) V13 is provided in the circulation gas exhaust passage portion 31c between the branch portion of the heating passage portion 31b and the connection portion of the cooling outside air introduction portion 31g. Further, a fourteenth switching valve (cooling outside air introduction valve) V14 is provided in the cooling outside air introduction portion 31g. Furthermore, a fifteenth switching valve (replenishment outside air introduction valve) V15 is provided in the supplementary outside air introduction section 31d. In the first bypass channel 31e, a sixteenth switching valve V16 is provided between the branch of the heating channel 31b and the branch of the second bypass channel 31f. Furthermore, the 17th switching valve V17 is provided in the 2nd bypass flow-path part 31f in the branch part vicinity of the 1st bypass flow-path part 31e.

４１は、循環ガス温度検出器Ｔ１と排ガス温度検出器Ｔ２と排ガス成分検出器Ｍに基づいて、第１〜第９切替弁Ｖ１〜Ｖ９および第１１〜第１７切替弁Ｖ１１〜Ｖ１７とを操作する熱分解用コントローラである。 41 operates the first to ninth switching valves V1 to V9 and the first to seventeenth switching valves V11 to V17 based on the circulating gas temperature detector T1, the exhaust gas temperature detector T2, and the exhaust gas component detector M. It is a controller for thermal decomposition.

（炉運転状態）
図１を参照して、焼却炉１１の通常の運転状態を説明する。
通常の運転状態では、第１〜第７切替弁Ｖ１〜Ｖ７を開、残りの第８，第９切替弁Ｖ８，Ｖ９および第１１〜第１７切替弁Ｖ１１〜Ｖ１７を閉とする。 (Furnace operating state)
A normal operation state of the incinerator 11 will be described with reference to FIG.
In a normal operation state, the first to seventh switching valves V1 to V7 are opened, and the remaining eighth and ninth switching valves V8 and V9 and the first to seventeenth switching valves V11 to V17 are closed.

１）冷却塔１３から排出された排ガス中に、活性炭供給装置１４から活性炭を吹き込み、活性炭に排ガス中の重金属類やダイオキシンなどの有害物質を吸着させる。さらに薬剤供給装置１５から排ガス中に消石灰など、中和用のアルカリ性薬剤を吹き込み、このアルカリ性薬剤と、排ガス中の塩化水素や硫黄酸化物などを反応させる。そして、排ガスをバグフィルタ１６に導入して、これらの反応生成物と活性炭吸着物を煤塵と共に捕集する。 1) Activated carbon is blown into the exhaust gas discharged from the cooling tower 13 from the activated carbon supply device 14, and adsorbs harmful substances such as heavy metals and dioxin in the exhaust gas to the activated carbon. Further, a neutralizing alkaline chemical such as slaked lime is blown into the exhaust gas from the chemical supply device 15, and this alkaline chemical is reacted with hydrogen chloride, sulfur oxide, etc. in the exhaust gas. And exhaust gas is introduce | transduced into the bag filter 16, and these reaction products and activated carbon adsorbate are collected with soot dust.

２）排ガスを再加熱用の熱交換器（被加熱側）１７とガス再加熱器１８に順次導入して、触媒脱硝方式に適した温度に加熱した後、触媒反応塔２０に送られる。触媒反応塔２０では、アンモニア供給装置２３からアンモニアガスなどの還元用薬剤を排ガス中に噴射し、排ガスを触媒に接触させることで、窒素酸化物が還元されて除去される。 2) The exhaust gas is sequentially introduced into a reheat heat exchanger (heated side) 17 and a gas reheater 18 and heated to a temperature suitable for the catalyst denitration system, and then sent to the catalyst reaction tower 20. In the catalytic reaction tower 20, nitrogen oxides are reduced and removed by injecting a reducing agent such as ammonia gas into the exhaust gas from the ammonia supply device 23 and bringing the exhaust gas into contact with the catalyst.

３）排ガスを熱交換器（加熱側）１７に導入し、バグフィルタ１６から触媒反応塔２０に導入される排ガスを加熱することにより熱回収した後、誘引通風機２１により煙突２２を介して大気中に排出する。 3) After exhaust gas is introduced into the heat exchanger (heating side) 17 and heat is recovered by heating the exhaust gas introduced from the bag filter 16 to the catalytic reaction tower 20, the atmosphere is passed through the chimney 22 by the induction fan 21. Drain inside.

（炉運転−熱分解作業）
図２を参照して、焼却炉１１の運転中に触媒反応塔２０や熱交換器（加熱側）１７に堆積した硫酸のアンモニウム塩を熱分解する方法について説明する。 (Furnace operation-pyrolysis work)
With reference to FIG. 2, a method for thermally decomposing ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 and the heat exchanger (heating side) 17 during the operation of the incinerator 11 will be described.

１１）焼却炉１１内にアンモニア水や尿素水、水を噴霧するなどにより、排ガス中のＮＯ_Ｘを低減した低ＮＯ_Ｘ運転を行う。
１２）通常の運転状態から第３切替弁Ｖ３、第４切替弁Ｖ４、第７切替弁Ｖ７を閉じ、第８切替弁Ｖ８および第９切替弁Ｖ９を開けて、バグフィルタ１６から排出された排ガスを、バイパス排気ライン３０に導入し、誘引送風機２１から煙突２２を介して排出する。同時に、第１１切替弁Ｖ１１および第１２切替弁Ｖ１２を開け（第５，第６切替弁Ｖ５，Ｖ６は開、第１３〜第１７切替弁Ｖ１３〜Ｖ１７は閉）、循環送風機３２を起動して系内に残留している排ガスを循環加熱ガスとして循環させるとともに、循環ガス加熱器３３を起動して循環加熱ガスを加熱する。 11) aqueous ammonia or urea solution into the incinerator 11, such as by spraying water, performing low NO _X operation with reduced NO _X in the exhaust gas.
12) From the normal operation state, the third switching valve V3, the fourth switching valve V4, and the seventh switching valve V7 are closed, the eighth switching valve V8 and the ninth switching valve V9 are opened, and the exhaust gas discharged from the bag filter 16 Is introduced into the bypass exhaust line 30 and discharged from the induction blower 21 via the chimney 22. At the same time, the eleventh switching valve V11 and the twelfth switching valve V12 are opened (the fifth and sixth switching valves V5 and V6 are opened, and the thirteenth to seventeenth switching valves V13 to V17 are closed), and the circulation blower 32 is activated. The exhaust gas remaining in the system is circulated as a circulating heating gas, and the circulating gas heater 33 is activated to heat the circulating heating gas.

１３）熱分解用コントローラ４１では、循環ガス温度検出器Ｔ１により循環加熱ガスの温度を監視しており、硫酸のアンモニウム塩の分解温度（硫酸アンモニウムは２８０℃）以上で、たとえば３２０℃前後となると、循環ガス加熱器３３による加熱を制御して、循環加熱ガスを所定範囲内の温度（たとえば３２０℃以上、４５０℃以下）で所定時間保持することにより、触媒反応塔２０内と熱交換器（加熱側）１７内に堆積した硫酸のアンモニウム塩を熱分解する。熱分解されたアンモニアガスや硫黄酸化物は、循環加熱ガスに同伴される。 13) In the thermal decomposition controller 41, the temperature of the circulating heating gas is monitored by the circulating gas temperature detector T1, and when the decomposition temperature of the ammonium salt of sulfuric acid (ammonium sulfate is 280 ° C) or higher, for example, around 320 ° C, By controlling the heating by the circulating gas heater 33 and holding the circulating heated gas at a temperature within a predetermined range (for example, 320 ° C. or higher and 450 ° C. or lower) for a predetermined time, the inside of the catalytic reaction tower 20 and the heat exchanger (heating) Side) Ammonium salt of sulfuric acid deposited in 17 is thermally decomposed. The thermally decomposed ammonia gas and sulfur oxide are accompanied by the circulating heating gas.

ここで、分解加熱ガスの温度を３２０℃以上としたのは、３２０℃未満では、硫酸のアンモニウム塩の熱分解が十分に行われない恐れがあるからであり、また４５０℃以上では、触媒反応塔２０の触媒や熱交換器１７の伝熱管などの構成部材に悪影響を与える恐れがあるからである。 Here, the reason why the temperature of the decomposition heating gas is set to 320 ° C. or more is that if it is less than 320 ° C., there is a possibility that the thermal decomposition of the ammonium salt of sulfuric acid may not be performed sufficiently. This is because there is a possibility of adversely affecting components such as the catalyst of the tower 20 and the heat transfer tubes of the heat exchanger 17.

１４）予め実験されたデータに基づいて、触媒反応塔２０や熱交換器（被加熱側）１７の硫酸のアンモニウム塩が十分に熱分解される所定時間が経過すると、熱分解用コントローラ４１の操作指令により、第１３切替弁Ｖ１３をゆっくりと開け、循環加熱ガスの一部を排ガス処理ライン１０の排ガスに合流させて、バグフィルタ１６に導入する。この時、熱分解用コントローラ４１は、排ガス温度検出器Ｔ２により排ガスの温度を監視し、循環加熱ガスにより排ガスの温度が上がり過ぎてバグフィルタ１６に悪影響を及ぼさないように、第１３切替弁Ｖ１３を操作して循環加熱ガスの排出量を制御する。また排ガス成分検出器Ｍにより煙突２２から排出されるアンモニアガス（ＮＨ_３）および／または硫黄酸化物（ＳＯ_Ｘ）の濃度を監視し、大気中に放出する排ガスの中のアンモニアガスと硫黄酸化物の濃度が上がりすぎないように、第１３切替弁Ｖ１３を操作して循環加熱ガスの排出量を制御する。 14) When a predetermined period of time during which the ammonium salt of sulfuric acid in the catalytic reaction tower 20 and the heat exchanger (to-be-heated) 17 is sufficiently pyrolyzed has elapsed based on previously experimental data, the operation of the controller 41 for pyrolysis In response to the command, the thirteenth switching valve V13 is slowly opened, and a part of the circulating heated gas is merged with the exhaust gas of the exhaust gas treatment line 10 and introduced into the bag filter 16. At this time, the pyrolysis controller 41 monitors the temperature of the exhaust gas by the exhaust gas temperature detector T2, and the thirteenth switching valve V13 is used so that the temperature of the exhaust gas is excessively raised by the circulating heating gas and does not adversely affect the bag filter 16. To control the discharge amount of the circulating heating gas. Further, the concentration of ammonia gas (NH ₃ ) and / or sulfur oxide (SO _X ) discharged from the chimney 22 by the exhaust gas component detector M is monitored, and ammonia gas and sulfur oxide in the exhaust gas discharged into the atmosphere. The discharge amount of the circulating heated gas is controlled by operating the thirteenth switching valve V13 so that the concentration of the gas does not increase excessively.

さらにガス循環ライン３１の循環加熱ガスが減少するため、第１５切替弁Ｖ１５をあけて補充用外気導入流路部３１ｄからガス循環ライン３１に外気を導入し、循環ガス加熱器３３により循環加熱ガスを加熱する。 Further, since the circulating heating gas in the gas circulation line 31 decreases, the 15th switching valve V15 is opened to introduce the outside air into the gas circulation line 31 from the refilling outside air introduction flow path portion 31d, and the circulating gas heater 33 circulates the heating gas. Heat.

１５）排出される循環加熱ガスに同伴されたアンモニアガスと硫黄酸化物は、合流する排ガスにより冷却されて、固体状の硫酸アンモニウム（硫安）や硫酸水素アンモニウム（酸性硫安）となってバグフィルタ１６で捕集され、さらに排ガス中の消石灰などのアルカリ性薬剤と反応したり、活性炭に吸着されて、反応生成物や活性炭吸着物がバグフィルタ１６により捕集される。 15) Ammonia gas and sulfur oxide entrained in the discharged circulating heating gas are cooled by the combined exhaust gas to form solid ammonium sulfate (ammonium sulfate) or ammonium hydrogen sulfate (acidic ammonium sulfate). It is collected and further reacted with an alkaline agent such as slaked lime in the exhaust gas or adsorbed on activated carbon, and the reaction product and activated carbon adsorbate are collected by the bag filter 16.

１６）なお、上記方法では、触媒反応塔２０と熱交換器１７に堆積した硫酸のアンモニウム塩を同時に熱分解させる場合を説明したが、触媒反応塔２０と熱交換器１７をそれぞれ単独で熱分解させることもできる。 16) In the above method, the case where the ammonium salt of sulfuric acid deposited on the catalyst reaction tower 20 and the heat exchanger 17 is simultaneously pyrolyzed has been described. However, the catalyst reaction tower 20 and the heat exchanger 17 are each pyrolyzed independently. It can also be made.

たとえば触媒反応塔２０に堆積した硫酸のアンモニウム塩のみを熱分解する場合、第６切替弁Ｖ６、第１１切替弁Ｖ１１を閉じて第１７切替弁Ｖ１７を開ける（第１６切替弁Ｖ１６は閉）ことにより、触媒反応塔２０から排出された循環加熱ガスを、第１バイパス流路部３１ｅおよび第２バイパス流路部３１ｆを介して加熱流路部３１ｂに循環させればよい。 For example, when only the ammonium salt of sulfuric acid deposited in the catalytic reaction tower 20 is thermally decomposed, the sixth switching valve V6 and the eleventh switching valve V11 are closed and the seventeenth switching valve V17 is opened (the sixteenth switching valve V16 is closed). Thus, the circulating heating gas discharged from the catalytic reaction tower 20 may be circulated to the heating channel portion 31b via the first bypass channel portion 31e and the second bypass channel portion 31f.

また熱交換器１７に堆積した硫酸のアンモニウム塩のみを熱分解する場合、第１２切替弁Ｖ１２、第５切替弁Ｖ５、第１７切替弁Ｖ１７を閉じ、第６切替弁Ｖ６、第１６切替弁Ｖ１６を開けることにより、循環ガス加熱器３３から排出された循環加熱ガスを、第１バイパス流路部３１ｅ、共用流路部３１ａから熱交換器（加熱側）１７に導入すればよい。 When only the ammonium salt of sulfuric acid deposited on the heat exchanger 17 is thermally decomposed, the twelfth switching valve V12, the fifth switching valve V5, and the seventeenth switching valve V17 are closed, and the sixth switching valve V6 and the sixteenth switching valve V16. The circulation heating gas discharged from the circulation gas heater 33 may be introduced into the heat exchanger (heating side) 17 from the first bypass channel 31e and the common channel 31a.

（炉停止−熱分解作業）
図３を参照して、焼却炉１１の停止中に、触媒反応塔２０や熱交換器（加熱側）１７に堆積した硫酸のアンモニウム塩を熱分解する方法を説明する。 (Furnace shutdown-pyrolysis work)
With reference to FIG. 3, a method for thermally decomposing ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 and the heat exchanger (heating side) 17 while the incinerator 11 is stopped will be described.

２１）焼却炉１１を停止する前に、活性炭供給装置１４および薬剤供給装置１５からバグフィルタ１６に、活性炭やアルカリ性薬剤を数十分から数時間程度吹き込んでおく。
２２）第１切替弁Ｖ１、第３切替弁Ｖ３、第４切替弁Ｖ４を閉じ、第１１切替弁Ｖ１１、第１２切替弁Ｖ１２、第５切替弁Ｖ５，第６切替弁Ｖ６を開ける（第７〜第９切替弁Ｖ７〜Ｖ９、第１３〜第１７切替弁Ｖ１３〜Ｖ１７は閉）。そして、循環送風機３２を起動して、ガス循環ライン３１の系内に残留している排ガスを循環加熱ガスとして循環させるとともに、循環ガス加熱器３３を起動して循環加熱ガスを加熱する。 21) Before stopping the incinerator 11, activated carbon or an alkaline chemical is blown into the bag filter 16 from the activated carbon supply device 14 and the chemical supply device 15 for about several tens of minutes to several hours.
22) The first switching valve V1, the third switching valve V3, and the fourth switching valve V4 are closed, and the eleventh switching valve V11, the twelfth switching valve V12, the fifth switching valve V5, and the sixth switching valve V6 are opened (seventh). To ninth switch valve V7 to V9 and thirteenth to seventeenth switch valves V13 to V17 are closed). Then, the circulation blower 32 is activated to circulate the exhaust gas remaining in the system of the gas circulation line 31 as the circulation heating gas, and the circulation gas heater 33 is activated to heat the circulation heating gas.

２３）熱分解用コントローラ４１では、先の工程１３）と同様に、循環ガス温度検出器Ｔ１により循環加熱ガスの温度を監視しており、硫酸のアンモニウム塩の分解温度（硫酸アンモニウムは２８０℃）以上で、たとえば３２０℃前後となると、循環ガス加熱器３３の加熱を制御して、循環加熱ガスを所定範囲内の温度（たとえば３２０℃以上、４５０℃以下）を所定時間保持する。そして、循環加熱ガスにより触媒反応塔２０内と熱交換器（加熱側）１７内に堆積した硫酸のアンモニウム塩を熱分解する。熱分解されたアンモニアガスや硫黄酸化物は、循環加熱ガスに同伴される。 23) In the thermal decomposition controller 41, the temperature of the circulating heating gas is monitored by the circulating gas temperature detector T1, as in the previous step 13), and the decomposition temperature of the ammonium salt of sulfuric acid (ammonium sulfate is 280 ° C.) or higher. Thus, for example, when the temperature is around 320 ° C., the heating of the circulating gas heater 33 is controlled to maintain the circulating heating gas at a temperature within a predetermined range (for example, 320 ° C. or higher and 450 ° C. or lower) for a predetermined time. Then, the ammonium salt of sulfuric acid deposited in the catalytic reaction tower 20 and the heat exchanger (heating side) 17 is thermally decomposed by the circulating heating gas. The thermally decomposed ammonia gas and sulfur oxide are accompanied by the circulating heating gas.

２４）先の工程１４）と同様に、予め実験されたデータに基づいて、触媒反応塔２０や熱交換器（加熱側）１７の硫酸のアンモニウム塩が熱分解される所定時間が経過すると、熱分解用コントローラ４１の操作指令により、第１３切替弁Ｖ１３、第１４切替弁Ｖ１４、第８切替弁Ｖ８および第９切替弁Ｖ９を開けると同時に誘引送風機２１を起動する。すなわち、第１３切替弁Ｖ１３を開けて循環加熱ガスの一部を循環ガス排出経路部３１ｃに送ると同時に、第１４切替弁Ｖ１４を開け、冷却用外気導入流路部３１ｇから循環ガス排出経路部３１ｃに外気を導入し、外気により排出される循環加熱ガスを冷却する。そしてこの循環加熱ガスと外気の混合ガスを、排ガス処理ライン１０を介してバグフィルタ１６に導入する。この時、循環加熱ガスに同伴されたアンモニアガスと硫黄酸化物は、合流された外気と混合により冷却され、固体状の硫酸アンモニウム（硫安）や硫酸水素アンモニウム（酸性硫安）となってバグフィルタ１６で捕集されたり、さらにバグフィルタ１６に残留している消石灰などのアルカリ性薬剤と反応したり、活性炭に吸着されてバグフィルタ１６により捕集される。そして、混合ガスは、バイパス排気ライン３０から誘引送風機２１および煙突２２を介して排出される。 24) As in the previous step 14), when a predetermined time for the ammonium salt of sulfuric acid in the catalytic reaction tower 20 and the heat exchanger (heating side) 17 to be thermally decomposed has elapsed based on previously experimented data, In response to an operation command from the decomposition controller 41, the induction fan 21 is activated simultaneously with opening the thirteenth switching valve V13, the fourteenth switching valve V14, the eighth switching valve V8, and the ninth switching valve V9. That is, the thirteenth switching valve V13 is opened and a part of the circulating heating gas is sent to the circulating gas discharge path portion 31c. At the same time, the fourteenth switching valve V14 is opened and the circulating gas discharge path portion from the cooling outside air introduction flow path portion 31g is opened. The outside air is introduced into 31c, and the circulating heated gas discharged by the outside air is cooled. Then, the mixed gas of the circulating heating gas and the outside air is introduced into the bag filter 16 through the exhaust gas treatment line 10. At this time, the ammonia gas and sulfur oxide entrained in the circulating heating gas are cooled by mixing with the combined outside air, and become solid ammonium sulfate (ammonium sulfate) or ammonium hydrogen sulfate (acidic ammonium sulfate) by the bag filter 16. It is collected or further reacted with an alkaline agent such as slaked lime remaining on the bag filter 16 or adsorbed on the activated carbon and collected by the bag filter 16. The mixed gas is discharged from the bypass exhaust line 30 via the induction blower 21 and the chimney 22.

２５）熱分解用コントローラ４１では、排ガス温度検出器Ｔ２によりバグフィルタ１６出口の排ガスの温度を監視するとともに、排ガス成分検出器により煙突２２から排出されるアンモニアガス（ＮＨ_４）および／または硫黄酸化物（ＳＯ_Ｘ）の濃度を監視しており、排ガスの温度が上がり過ぎてバグフィルタ１６に悪影響を及ぼさないように、また大気中に放出する排ガスの中のアンモニアガスと硫黄酸化物の濃度が上がりすぎないように、第１３切替弁Ｖ１３と第１４切替弁Ｖ１４の開度を調整して循環加熱ガスの排出量を制御する。さらにガス循環ライン３１の循環加熱ガスが減少するため、第１５切替弁Ｖ１５をあけて補充用外気導入流路部３１ｄからガス循環ライン３１に外気を導入し、循環ガス加熱器３３により循環加熱ガスを加熱する。 25) In the pyrolysis controller 41, the temperature of the exhaust gas at the bag filter 16 outlet is monitored by the exhaust gas temperature detector T2, and ammonia gas (NH ₄ ) and / or sulfur oxidation discharged from the chimney 22 by the exhaust gas component detector monitors the concentration of the object (sO _X), so as not to adversely affect the temperature of the exhaust gas is too high the bag filter 16, also the concentration of ammonia gas and sulfur oxides in the exhaust gas released into the atmosphere The exhaust amount of the circulating heating gas is controlled by adjusting the opening degrees of the thirteenth switching valve V13 and the fourteenth switching valve V14 so as not to increase too much. Further, since the circulating heating gas in the gas circulation line 31 decreases, the 15th switching valve V15 is opened to introduce the outside air into the gas circulation line 31 from the refilling outside air introduction flow path portion 31d, and the circulating gas heater 33 causes the circulation heating gas Heat.

２６）なお、上記方法では、触媒反応塔２０と熱交換器１７に堆積した硫酸のアンモニウム塩を同時に熱分解する場合を説明したが、工程１６）と同様に、触媒反応塔２０または熱交換器１７の硫酸のアンモニウム塩をそれぞれ単独で熱分解させることもできる。 26) In the above method, the case where the ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 and the heat exchanger 17 is pyrolyzed at the same time has been described. However, as in the step 16), the catalytic reaction tower 20 or the heat exchanger. The 17 sulfuric acid ammonium salts can also be thermally decomposed independently.

（実施例１の効果）
実施例１によれば、
Ａ）バグフィルタ１６から排出される排ガスを、誘引送風機２１から煙突２２を介して排出するバイパス排気ライン３０と、循環送風機３２により循環ガス加熱器３３を介して循環加熱ガスを、硫酸のアンモニウム塩を熱分解可能な温度に加熱して、触媒反応塔２０や熱交換器１７に循環させるガス循環ライン３１を設けたので、焼却炉１１の運転中に触媒反応塔２０や熱交換器１７に堆積した硫酸アンモニウム［硫安、(NH₄)₂SO₄］や硫酸水素アンモニウム［酸性硫安、NH₄HSO₄］などの硫酸のアンモニウム塩を、効果的に熱分解することができる。このように、ガス循環ライン３１に沿って循環加熱ガスを加熱、循環させて繰り返し使用できるので、熱エネルギコストを削減することができる。そして、配管構造や触媒脱硝器の構造を簡略化できて、設備コストを低減することができる。 (Effect of Example 1)
According to Example 1,
A) The exhaust gas discharged from the bag filter 16 is discharged from the induction blower 21 through the chimney 22, and the circulation heating gas is supplied from the circulation blower 32 via the circulation gas heater 33 to the ammonium salt of sulfuric acid. Since the gas circulation line 31 is provided to heat the gas to a temperature at which it can be pyrolyzed and circulates to the catalyst reaction tower 20 and the heat exchanger 17, the gas is deposited on the catalyst reaction tower 20 and the heat exchanger 17 during the operation of the incinerator 11. Ammonium sulfates such as ammonium sulfate [ammonium sulfate, (NH ₄ ) ₂ SO ₄ ] and ammonium hydrogen sulfate [acid ammonium sulfate, NH ₄ HSO ₄ ] can be effectively thermally decomposed. Thus, since the circulating heating gas can be heated and circulated along the gas circulation line 31 and repeatedly used, the thermal energy cost can be reduced. And the piping structure and the structure of the catalyst denitrator can be simplified, and the equipment cost can be reduced.

Ｂ）循環分解ガスに同伴された熱分解ガス（アンモニアガスと硫黄酸化物）は、バグフィルタ１６の入口で合流される排ガスにより冷却され、固体状の硫酸アンモニウム（硫安）や硫酸水素アンモニウム（酸性硫安）となったり、排ガス中の消石灰などのアルカリ性薬剤と反応したり、活性炭に吸着されてバグフィルタ１６により捕集される。したがって、大気中に排出される排ガスに熱分解ガスの成分が含まれるのを効果的に防止することができる。 B) The pyrolysis gas (ammonia gas and sulfur oxide) entrained in the circulating cracked gas is cooled by the exhaust gas joined at the inlet of the bag filter 16, and is solid ammonium sulfate (ammonium sulfate) or ammonium hydrogen sulfate (acid ammonium sulfate). ), Reacts with an alkaline agent such as slaked lime in exhaust gas, or is adsorbed by activated carbon and collected by the bag filter 16. Accordingly, it is possible to effectively prevent the pyrolysis gas component from being included in the exhaust gas discharged into the atmosphere.

Ｃ）焼却炉１１が停止中であっても、ガス循環ライン３１に循環加熱ガスを循環させ、触媒反応塔２０や熱交換器１７に堆積した硫酸のアンモニウム塩を熱分解することができる。また一部を導出する循環加熱ガスに、冷却用外気導入流路部３１ｇから外気を混合して冷却することができるので、バグフィルタ１６に適正温度の混合ガスを導入することができ、バグフィルタ１６の焼損を防止できる。 C) Even when the incinerator 11 is stopped, the circulating heating gas can be circulated through the gas circulation line 31 to thermally decompose the ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 or the heat exchanger 17. In addition, since a part of the circulating heating gas leading out can be cooled by mixing outside air from the cooling outside air introduction flow path portion 31g, a mixed gas at an appropriate temperature can be introduced into the bag filter 16, and the bag filter 16 burnout can be prevented.

Ｄ）熱分解用コントローラ４１により、循環加熱ガスの温度を、硫酸のアンモニウム塩の熱分解温度以上に制御することにより、硫酸のアンモニウム塩を効果的に熱分解できる。また循環加熱ガスを排出する時に、ガス循環ライン３１から導出される循環加熱ガスと排ガスとを混合して、排ガスの温度を制御することにより、バグフィルタ１６の焼損を防止することができる。
Ｅ）焼却炉１１の停止中であっても、熱分解用コントローラ４１により、循環加熱ガスの温度を、硫酸のアンモニウム塩の熱分解温度以上に制御することにより、触媒反応塔２０や熱交換器１７の硫酸のアンモニウム塩を効果的に熱分解できる。またガス循環ライン３１から導出される循環加熱ガスを、冷却用外気を混合して冷却することにより、循環加熱ガスに含まれる熱分解成分を、固体化するとともに、さらに残存する中和用や吸着用の薬剤と反応、吸着させてバグフィルタ１６で捕集することができる。そしてバグフィルタ１６の焼損を防止することもできる。 D) By controlling the temperature of the circulating heating gas to be equal to or higher than the thermal decomposition temperature of the sulfuric acid ammonium salt by the thermal decomposition controller 41, the sulfuric acid ammonium salt can be effectively thermally decomposed. Further, when the circulating heating gas is discharged, the circulating heating gas derived from the gas circulation line 31 and the exhaust gas are mixed to control the temperature of the exhaust gas, thereby preventing the bag filter 16 from being burned out.
E) Even when the incinerator 11 is stopped, the temperature of the circulating heating gas is controlled by the thermal decomposition controller 41 to be equal to or higher than the thermal decomposition temperature of the ammonium salt of sulfuric acid, so that the catalytic reaction tower 20 and the heat exchanger 17 Ammonium salt of sulfuric acid can be effectively thermally decomposed. Further, the circulating heating gas derived from the gas circulation line 31 is cooled by mixing the outside air for cooling, so that the pyrolysis component contained in the circulating heating gas is solidified and further left for neutralization and adsorption. It can be collected by the bag filter 16 after being reacted and adsorbed with a chemical for use. Further, it is possible to prevent the bag filter 16 from being burned out.

［実施例２］
次に、本発明の実施例２を図４〜図６に基づいて説明する。
（基本構造）
この排ガス処理設備は、バグフィルタの結露による露点腐食や消石灰の潮解防止のために、起動時に温風をバグフィルタに送り予熱するための予熱ガス加熱ラインが設けられており、予熱ガス加熱ラインに予熱用加熱器と予熱用送風機が具備されている。この実施例２は、図５に示すように、この予熱ガス加熱ライン５０を具備した排ガス処理設備において、実施例１と同様にガス循環ライン３１を設け、予熱用加熱器を循環ガス加熱器３３Ａとし、予熱用送風機を循環送風機３２Ａとして使用する。以下、実施例１と同一部材には同一符号を付して説明を省略する。 [Example 2]
Next, a second embodiment of the present invention will be described with reference to FIGS.
(Basic structure)
This exhaust gas treatment facility is equipped with a preheating gas heating line for preheating by sending warm air to the bag filter at the start-up to prevent dew point corrosion due to condensation on the bag filter and deliquescence of slaked lime. A preheating heater and a preheating blower are provided. As shown in FIG. 5, in the second embodiment, in the exhaust gas treatment facility provided with the preheating gas heating line 50, the gas circulation line 31 is provided similarly to the first embodiment, and the preheating heater is used as the circulation gas heater 33 </ b> A. And a preheating blower is used as the circulation blower 32A. Hereinafter, the same members as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

（予熱ガス加熱ライン）
予熱ガス加熱ライン５０は、バグフィルタ１６の出口側の排ガス処理ライン１０から分岐されて、循環送風機３２Ａの入口に接続された吸引流路部５０ａと、循環ガス加熱器３３Ａの出口からバグフィルタ１６の入口側の排ガス処理ライン１０に接続された吐出流路部５０ｂを具備し、循環送風機３２Ａの出口と循環ガス加熱器３３Ａの入口が接続されている。 (Preheating gas heating line)
The preheating gas heating line 50 is branched from the exhaust gas treatment line 10 on the outlet side of the bag filter 16 and is connected to the inlet of the circulation fan 32A, and the bag filter 16 is connected to the outlet of the circulation gas heater 33A. The discharge flow path part 50b connected to the exhaust gas treatment line 10 on the inlet side of the gas is provided, and the outlet of the circulation fan 32A and the inlet of the circulation gas heater 33A are connected.

そして、吐出流路部５０ｂが循環ガス排気流路部３１ｃとして使用される。加熱流路部３１ｂが、共用流路部３１ａの熱交換機１７の出口側に接続されて循環ガス加熱器３３Ａの入口に至る上流側加熱流路部３１ｂ１と、循環ガス加熱器３３Ａの出口から触媒反応塔２０の入口の排ガス処理ライン１０に接続された下流側加熱流路部３１ｂ２とで構成される。 And the discharge flow path part 50b is used as the circulation gas exhaust flow path part 31c. The heating channel 31b is connected to the outlet of the heat exchanger 17 of the common channel 31a and reaches the inlet of the circulating gas heater 33A. The upstream heating channel 31b1 reaches the inlet of the circulating gas heater 33A, and the outlet from the circulating gas heater 33A It is comprised with the downstream heating flow path part 31b2 connected to the exhaust gas treatment line 10 of the entrance of the reaction tower 20. FIG.

また、排ガス処理ライン１０の分岐口と上流側加熱流路部３１ｂ１の接続部の間の吸引流路部５０ａに排出バイパス流路部３１ｈが分岐され、排出バイパス流路部３１ｈの出口が循環ガス排気流路部３１ｃ（吐出流路部５０ｂ）に接続されている。そして循環ガス排気流路部３１ｃ（吐出流路部５０ｂ）に冷却用外気導入流路部３１ｇが接続されている。 Further, the exhaust bypass flow path portion 31h is branched to the suction flow path portion 50a between the branch port of the exhaust gas treatment line 10 and the connection portion of the upstream heating flow path portion 31b1, and the outlet of the exhaust bypass flow path portion 31h is the circulating gas. It is connected to the exhaust flow path part 31c (discharge flow path part 50b). A cooling outside air introduction flow path 31g is connected to the circulation gas exhaust flow path 31c (discharge flow path 50b).

さらに、上流側加熱流路部３１ｂ１の接続部と循環送風機３２Ａの入口の間の吸引流路部５０ａに、補充用外気導入流路部３１ｄが接続されている。
予熱ガスライン５０には、吸引流路部５０ａの入口から排出バイパス流路部３１ｈの分岐部の間に第２２切替弁Ｖ２２が設けられ、また吐出流路部５０ｂで、循環ガス加熱器３３Ａの出口から排出バイパス流路部３１ｈの接続部の間に第２３切替弁Ｖ２３が設けられ、この第２３切替弁Ｖ２３は分解処理中に開放されることはない。また吐出流路部５０ｂで冷却用外気導入流路部３１ｇの接続部と出口の間に、第２１切替弁Ｖ２１が設けられる。さらに、排出バイパス流路部３１ｈに第１３切替弁Ｖ１３が設けられる。 Furthermore, the replenishment outside air introduction flow path portion 31d is connected to the suction flow path portion 50a between the connection portion of the upstream heating flow path portion 31b1 and the inlet of the circulation fan 32A.
The preheating gas line 50 is provided with a twenty-second switching valve V22 between the inlet of the suction flow passage 50a and the branch of the discharge bypass flow passage 31h, and the discharge flow passage 50b is connected to the circulating gas heater 33A. A 23rd switching valve V23 is provided between the outlet and the connection portion of the discharge bypass flow passage 31h, and the 23rd switching valve V23 is not opened during the decomposition process. Further, a 21st switching valve V21 is provided between the connection part and the outlet of the cooling outside air introduction flow path part 31g in the discharge flow path part 50b. Furthermore, a thirteenth switching valve V13 is provided in the discharge bypass flow path portion 31h.

さらにまた、循環ガス加熱器３３Ａの出口近傍に循環ガス温度検出器Ｔ１が設置されている。
（炉運転状態）
焼却炉１１の運転状態は、図４に示すように、実施例１と同様であるため、説明を省略する。 Furthermore, a circulating gas temperature detector T1 is installed in the vicinity of the outlet of the circulating gas heater 33A.
(Furnace operating state)
Since the operation state of the incinerator 11 is the same as that of Example 1 as shown in FIG. 4, description is abbreviate | omitted.

（炉運転−熱分解作業）
図５を参照して、焼却炉１１の運転中に触媒反応塔２０や熱交換器（加熱側）１７に堆積した硫酸のアンモニウム塩を熱分解する方法について説明する。この熱分解方法は、実施例１と同様であるため、概略のみを説明する。 (Furnace operation-pyrolysis work)
With reference to FIG. 5, a method for thermally decomposing ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 and the heat exchanger (heating side) 17 during the operation of the incinerator 11 will be described. Since this thermal decomposition method is the same as in Example 1, only the outline will be described.

３１）焼却炉１１を低ＮＯ_Ｘ運転する。
３２）バグフィルタ１６から排出された排ガスの排出経路を、排ガス処理ライン１０からバイパス排気ライン３０に切り替える。循環送風機３２Ａを起動してガス循環ライン３１の系内に残留している排ガスを循環加熱ガスとして循環させ、循環ガス加熱器３３Ａにより循環加熱ガスを加熱する。 31) The incinerator 11 is operated at low NO _X.
32) The exhaust gas exhaust route discharged from the bag filter 16 is switched from the exhaust gas treatment line 10 to the bypass exhaust line 30. The circulation blower 32A is activated to circulate the exhaust gas remaining in the system of the gas circulation line 31 as a circulation heating gas, and the circulation heating gas is heated by the circulation gas heater 33A.

３３）熱分解用コントローラ４１により循環加熱ガスの温度が、硫酸のアンモニウム塩の分解温度以上の３２０℃前後となると、循環ガス加熱器３３Ａを制御して、循環加熱ガスを３２０℃以上、４５０℃以下で所定時間保持する。これにより、触媒反応塔２０内と熱交換器（加熱側）１７内に堆積した硫酸のアンモニウム塩を熱分解する。 33) When the temperature of the circulating heating gas reaches about 320 ° C. above the decomposition temperature of the ammonium salt of sulfuric acid by the thermal decomposition controller 41, the circulating gas heater 33A is controlled to make the circulating heating gas at 320 ° C. or higher and 450 ° C. The following is held for a predetermined time. Thereby, the ammonium salt of sulfuric acid deposited in the catalytic reaction tower 20 and the heat exchanger (heating side) 17 is thermally decomposed.

３４）硫酸のアンモニウム塩の熱分解に要する時間が経過すると、第２１切替弁Ｖ２１を開放した後、第１３切替弁Ｖ１３をゆっくりと開けて、循環加熱ガスの一部を排ガス処理ライン１０の排ガスに合流させて、バグフィルタ１６に導入する。この時、熱分解用コントローラ４０により、バグフィルタ１６に悪影響を及ぼさないように循環加熱ガスの排出量を制御する。また排ガス成分検出器Ｍにより煙突２２から排出されるアンモニアガス（ＮＨ_３）と硫黄酸化物（ＳＯ_Ｘ）の濃度が上がりすぎないように、第１３切替弁Ｖ１３を制御して循環加熱ガスの排出量を制御する。 34) When the time required for the thermal decomposition of the ammonium salt of sulfuric acid has elapsed, after the 21st switching valve V21 is opened, the 13th switching valve V13 is slowly opened, and a part of the circulating heating gas is exhausted from the exhaust gas treatment line 10. And is introduced into the bug filter 16. At this time, the amount of circulating heated gas discharged is controlled by the thermal decomposition controller 40 so as not to adversely affect the bag filter 16. Further, the exhaust gas component detector M controls the thirteenth switching valve V13 so that the concentration of ammonia gas (NH ₃ ) and sulfur oxide (SO _X ) discharged from the chimney 22 does not rise too much, thereby discharging the circulation heating gas. Control the amount.

さらに補充用外気導入流路部３１ｄからガス循環ライン３１に外気を導入して、ガス循環ライン３１の循環加熱ガスに混合する。
３５）排出される循環加熱ガスに同伴されたアンモニアガスと硫黄酸化物は、合流した排ガスにより冷却され、固体状の硫酸アンモニウム（硫安）や硫酸水素アンモニウム（酸性硫安）となったり、排ガス中の消石灰などのアルカリ性薬剤と反応したり、活性炭に吸着されて、反応生成物や活性炭吸着物がバグフィルタ１６により捕集される。 Further, outside air is introduced into the gas circulation line 31 from the replenishment outside air introduction flow path portion 31 d and mixed with the circulating heating gas in the gas circulation line 31.
35) Ammonia gas and sulfur oxide entrained in the circulating heating gas discharged are cooled by the combined exhaust gas to form solid ammonium sulfate (ammonium sulfate) or ammonium hydrogen sulfate (acid ammonium sulfate), or slaked lime in the exhaust gas The reaction product and the activated carbon adsorbate are collected by the bag filter 16 by reacting with an alkaline agent such as, or adsorbed on the activated carbon.

なお、上記方法では、触媒反応塔２０と熱交換器１７に堆積した硫酸のアンモニウム塩を同時に熱分解させる場合を説明したが、触媒反応塔２０と熱交換器１７をそれぞれ単独で熱分解させることもできる。 In the above method, the case where the ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 and the heat exchanger 17 is simultaneously pyrolyzed has been described. However, the catalytic reaction tower 20 and the heat exchanger 17 are each pyrolyzed independently. You can also.

（炉停止−熱分解作業）
図６を参照して、焼却炉１１の停止中に、触媒反応塔２０や熱交換器（加熱側）１７に堆積した硫酸のアンモニウム塩を熱分解する方法を説明する。この熱分解方法は、実施例１と同様であるため、概略のみを説明する。 (Furnace shutdown-pyrolysis work)
With reference to FIG. 6, a method for thermally decomposing ammonium salt of sulfuric acid deposited on the catalytic reaction tower 20 and the heat exchanger (heating side) 17 while the incinerator 11 is stopped will be described. Since this thermal decomposition method is the same as in Example 1, only the outline will be described.

４１）焼却炉１１の運転を停止する前に、活性炭供給装置１４および薬剤供給装置１５からバグフィルタ１６に、活性炭やアルカリ性薬剤を数十分から数時間程度吹き込んでおく。 41) Before stopping the operation of the incinerator 11, activated carbon or an alkaline chemical is blown into the bag filter 16 from the activated carbon supply device 14 and the chemical supply device 15 for about several tens of minutes to several hours.

４２）バグフィルタ１６から排出される排ガスの排出経路を、排ガス処理ライン１０からバイパス排気ライン３０に切り替える。ガス循環ライン３１を閉ループとした後、循環送風機３２Ａを起動して、ガス循環ライン３１の系内に残留している排ガスを循環加熱ガスとして循環させるとともに、循環ガス加熱器３３Ａを起動して循環加熱ガスを加熱する。 42) The exhaust gas exhaust path exhausted from the bag filter 16 is switched from the exhaust gas treatment line 10 to the bypass exhaust line 30. After the gas circulation line 31 is closed, the circulation blower 32A is activated to circulate the exhaust gas remaining in the system of the gas circulation line 31 as a circulation heating gas, and the circulation gas heater 33A is activated to circulate. Heat the heated gas.

４３）熱分解用コントローラ４１により循環加熱ガスの温度が、硫酸のアンモニウム塩の分解温度以上の３２０℃前後となると、循環ガス加熱器３３Ａを制御して、循環加熱ガスを３２０℃以上、４５０℃以下で所定時間保持する。これにより、触媒反応塔２０内と熱交換器（加熱側）１７内に堆積した硫酸のアンモニウム塩を熱分解する。 43) When the temperature of the circulating heating gas reaches about 320 ° C. above the decomposition temperature of the ammonium salt of sulfuric acid by the thermal decomposition controller 41, the circulating gas heater 33A is controlled to make the circulating heating gas at 320 ° C. or higher and 450 ° C. The following is held for a predetermined time. Thereby, the ammonium salt of sulfuric acid deposited in the catalytic reaction tower 20 and the heat exchanger (heating side) 17 is thermally decomposed.

４４）硫酸のアンモニウム塩の熱分解に要する時間が経過すると、第２１切替弁Ｖ２１を開放した後、第１３切替弁Ｖ１３をゆっくりと開けて、循環加熱ガスの一部を吐出流路部５０ｂに排出すると同時に、第１４切替弁Ｖ１４を開け、冷却用外気導入流路部３１ｇから吐出流路部５０ｂに外気を導入し、外気により、循環加熱ガスをバグフィルタ１６に適した温度まで冷却する。そして、循環加熱ガスと外気の混合ガスをバグフィルタ１６に導入する。循環加熱ガスに同伴された熱分解成分であるアンモニアガスと硫黄酸化物は、合流された外気と混合により冷却されて、固体状の硫酸アンモニウム（硫安）や硫酸水素アンモニウム（酸性硫安）となっており、バグフィルタ１６で捕集される。さらに循環加熱ガスに同伴された熱分解成分は、バグフィルタ１６に残留している消石灰などのアルカリ性薬剤と反応したり、活性炭に吸着されて、バグフィルタ１６により捕集される。そして、混合ガスがバイパス排気ライン３０から誘引送風機２１および煙突２２を介して排出される。 44) When the time required for the thermal decomposition of the ammonium salt of sulfuric acid has elapsed, after the 21st switching valve V21 is opened, the 13th switching valve V13 is slowly opened, and a part of the circulating heating gas is supplied to the discharge flow path section 50b. Simultaneously with the discharge, the fourteenth switching valve V14 is opened, the outside air is introduced from the cooling outside air introduction passage portion 31g to the discharge passage portion 50b, and the circulating heating gas is cooled to a temperature suitable for the bag filter 16 by the outside air. Then, a mixed gas of the circulating heating gas and the outside air is introduced into the bag filter 16. Ammonia gas and sulfur oxide, which are thermal decomposition components entrained by the circulating heating gas, are cooled by mixing with the outside air that has been combined into solid ammonium sulfate (ammonium sulfate) or ammonium hydrogensulfate (acidic ammonium sulfate). , And collected by the bug filter 16. Further, the pyrolysis component accompanying the circulating heating gas reacts with an alkaline agent such as slaked lime remaining in the bag filter 16 or is adsorbed by the activated carbon and collected by the bag filter 16. Then, the mixed gas is discharged from the bypass exhaust line 30 through the induction blower 21 and the chimney 22.

４５）この時、熱分解用コントローラ４１により、バグフィルタ１６に悪影響を及ぼさないように循環加熱ガスの排出量と外気の導入量が制御される。また排ガス成分検出器Ｍにより煙突２２から排出されるアンモニアガス（ＮＨ_３）と硫黄酸化物（ＳＯ_Ｘ）の濃度が上がりすぎないように、第１３切替弁Ｖ１３を操作して循環加熱ガスの排出量が制御される。さらに循環加熱ガスの減少に対応して、補充用外気導入流路部３１ｄからガス循環ライン３１に外気が導入される。 45) At this time, the discharge amount of the circulating heating gas and the introduction amount of the outside air are controlled by the thermal decomposition controller 41 so as not to adversely affect the bag filter 16. Further, the thirteenth switching valve V13 is operated to discharge the circulating heating gas so that the concentrations of ammonia gas (NH ₃ ) and sulfur oxide (SO _X ) discharged from the chimney 22 by the exhaust gas component detector M do not increase excessively. The amount is controlled. Further, outside air is introduced into the gas circulation line 31 from the supplementary outside air introduction flow path portion 31d in response to the decrease in the circulating heating gas.

４６）上記方法は、触媒反応塔２０と熱交換器１７に堆積した硫酸のアンモニウム塩を同時に熱分解させる場合であるが、触媒反応塔２０または熱交換器１７の硫酸のアンモニウム塩をそれぞれ単独で熱分解させることもできる。 46) The above method is a case where the ammonium salt of sulfuric acid deposited on the catalyst reaction tower 20 and the heat exchanger 17 is simultaneously pyrolyzed, but each of the ammonium salts of sulfuric acid in the catalyst reaction tower 20 or the heat exchanger 17 is independently used. It can also be pyrolyzed.

上記実施例２によれば、実施例１と同様の作用効果を奏することができる。また既存の予熱ガス加熱ライン５０の予熱用加熱器と予熱用送風機を利用して、循環ガス加熱器３３Ａおよび循環送風機３２Ａとして使用することができ、既存の設備を有効に利用して、設備コストを削減することができる。 According to the said Example 2, there can exist an effect similar to Example 1. FIG. Moreover, it can be used as the circulating gas heater 33A and the circulating blower 32A by using the preheating heater and the preheating blower of the existing preheating gas heating line 50, and the existing equipment is effectively used to reduce the equipment cost. Can be reduced.

１０排ガス処理ライン
１１焼却炉
１４活性炭供給装置
１５薬剤供給装置
１６バグフィルタ
１７熱交換器
２０触媒反応塔
２１誘引送風機
２２煙突
２３アンモニア供給装置
３０バイパス排気ライン
３１ガス循環ライン
３１ａ共用流路部
３１ｂ加熱流路部
３１ｂ１上流側加熱流路部
３１ｂ２下流側加熱流路部
３１ｃ循環ガス排気流路部
３１ｄ補充用外気導入流路部
３１ｅ第１バイパス流路部
３１ｆ第２バイパス流路部
３１ｇ冷却用外気導入流路部
３１ｈ排出バイパス流路部
３２循環送風機
３２Ａ循環送風機
３３循環ガス加熱器
３３Ａ循環ガス加熱器
４１熱分解用コントローラ
Ｔ１循環ガス温度検出器
Ｔ２排ガス温度検出器
Ｍ排ガス成分検出器
Ｖ１３第１３切換弁（循環ガス排出弁）
Ｖ１４第１４切換弁（冷却用外気導入弁）
Ｖ１５第１５切換弁（補充用外気導入弁）
５０予熱ガス加熱ライン
Ｖ２１〜Ｖ２３第２１〜第２３切替弁 DESCRIPTION OF SYMBOLS 10 Exhaust gas treatment line 11 Incinerator 14 Activated carbon supply apparatus 15 Chemical supply apparatus 16 Bag filter 17 Heat exchanger 20 Catalytic reaction tower 21 Induction fan 22 Chimney 23 Ammonia supply apparatus 30 Bypass exhaust line 31 Gas circulation line 31a Common flow path part 31b Heating Channel portion 31b1 Upstream heating channel portion 31b2 Downstream heating channel portion 31c Circulating gas exhaust channel portion 31d Replenishment outside air introduction channel portion 31e First bypass channel portion 31f Second bypass channel portion 31g Cooling outside air Introduction flow passage 31h Discharge bypass flow passage 32 Circulation fan 32A Circulation fan 33 Circulation gas heater 33A Circulation gas heater 41 Pyrolysis controller T1 Circulation gas temperature detector T2 Exhaust gas temperature detector M Exhaust gas component detector V13 13th Switching valve (circulation gas discharge valve)
V14 14th switching valve (cooling outside air introduction valve)
V15 Fifteenth switching valve (replenishment outside air introduction valve)
50 Preheating gas heating lines V21 to V23 21st to 23rd switching valves

Claims

Exhaust gas equipped with a bag filter for collecting salts, adsorbate and soot, heat exchanger, and catalytic reaction tower for removing nitrogen oxides from exhaust gas from the upstream side of the exhaust gas treatment line of exhaust gas discharged from the furnace A processing facility,
The heat exchanger heats the exhaust gas introduced into the catalytic reaction tower by the heated side where the exhaust gas introduced from the bag filter into the catalytic reaction tower is heated and the exhaust gas discharged from the catalytic reaction tower. And a heating side to
Provide a bypass exhaust line for exhausting the exhaust gas discharged from the bag filter to the atmosphere side,
A circulation fan, a circulation gas heater, the catalyst reaction tower, and a heating side of the heat exchanger are provided in a circulation direction of the circulation heating gas, and the catalyst reaction tower is bypassed from the circulation gas heater. And providing a gas circulation line having a first bypass flow path connected to the heating side of the heat exchanger ,
In the gas circulation line,
Decomposing ammonium salt of sulfuric acid deposited on the heating side of the catalytic reaction tower and the heat exchanger, respectively , with the circulating heating gas heated by the circulating gas heater , closing the first bypass flow path portion ;
Opening the first bypass flow path and closing the gas circulation line from the branch of the first bypass flow path to the catalytic reaction tower, and the heat exchange with the circulating heating gas heated by the circulating gas heater An exhaust gas treatment facility characterized by selectively decomposing the ammonium salt of sulfuric acid deposited on the heating side of the vessel .

The exhaust gas treatment facility according to claim 1,
A sixteenth switching valve for opening and closing the first bypass flow path section;
An exhaust gas treatment facility , comprising: a twelfth switching valve interposed between the catalyst reaction tower and a branch portion of the first bypass flow path portion in a gas circulation line .

The exhaust gas treatment facility according to claim 1 or 2 ,
Providing a circulating gas exhaust passage section for leading a part of the circulating heating gas of the gas circulation line to an inlet of the bag filter;
When exhausting a part of the circulating heating gas, a replenishment outside air introduction flow path section for introducing outside air into the gas circulation line is provided,
An exhaust gas treatment facility characterized in that a pyrolysis component of a circulating heating gas discharged from the circulating gas exhaust flow path is collected by the bag filter and discharged from the bypass exhaust line.

An exhaust gas treatment facility according to claim 3 ,
In the circulating gas exhaust flow path section, a cooling external air introduction flow path section for mixing and cooling the outside air with the circulating heating gas is provided,
An exhaust gas treatment facility characterized in that the circulating heating gas discharged from the circulating gas exhaust passage portion while the furnace is stopped is mixed with the outside air from the cooling outside air introduction passage portion, cooled, and introduced into the bag filter.

An exhaust gas treatment facility according to claim 3 ,
A circulating gas temperature detector for detecting the temperature of the circulating heating gas in the gas circulation line;
An exhaust gas temperature detector for detecting the exhaust gas temperature at the bag filter outlet;
An exhaust gas component detector for detecting the concentration of ammonia gas and / or sulfur oxide in the exhaust gas discharged from the bypass exhaust line;
A circulation gas discharge valve provided in the circulation gas exhaust passage,
A replenishment outside air introduction valve provided in the replenishment outside air introduction flow path section;
A thermal decomposition controller that controls the opening degree of the circulating gas discharge valve and the replenishment outside air introduction valve, and
The pyrolysis controller controls the temperature of the circulating heating gas based on the detected value of the circulating gas temperature detector during operation of the furnace, and the detected values of the exhaust gas temperature detector and the exhaust gas component detector. Based on the above, the opening degree of the circulating gas discharge valve and the supplementary outside air introduction valve is controlled.

The exhaust gas treatment facility according to claim 5 ,
A cooling outside air introduction valve provided in the cooling outside air introduction flow path section;
The thermal decomposition controller
While the furnace is stopped, the temperature of the circulating heating gas is maintained within a proper temperature range in which the ammonium salt of sulfuric acid can be decomposed for a predetermined time, and the ammonium salt of sulfuric acid deposited in the catalytic reaction tower and / or the heat exchanger After opening the circulating gas discharge valve, a part of the circulating heating gas is led out to the circulating gas exhaust passage part, and the outside air introduction valve for cooling is opened, and the outside air is supplied to the circulating gas exhaust passage part. An exhaust gas treatment facility that is introduced to cool the circulating heating gas and control the temperature of the mixed gas of the circulating heating gas and outside air to a range suitable for the bag filter.

The exhaust gas treatment facility according to claim 1 ,
An exhaust gas treatment facility characterized in that a bag filter preheater and a bag filter preheat blower installed for preheating a bag filter are installed in a gas circulation line so that they can be used as a circulation blower and a circulation gas heater.