JP2013142481A - Method and apparatus for denitration in incinerator - Google Patents

Method and apparatus for denitration in incinerator Download PDF

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JP2013142481A
JP2013142481A JP2012001663A JP2012001663A JP2013142481A JP 2013142481 A JP2013142481 A JP 2013142481A JP 2012001663 A JP2012001663 A JP 2012001663A JP 2012001663 A JP2012001663 A JP 2012001663A JP 2013142481 A JP2013142481 A JP 2013142481A
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incinerator
pipe
ammonia
furnace
sodium hydroxide
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Ryoji Samejima
良二 鮫島
Norio Maeda
典生 前田
Masaaki Kurata
昌明 倉田
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Takuma Co Ltd
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Abstract

PROBLEM TO BE SOLVED: To provide a method and an apparatus for denitration in an incinerator that can eliminate a catalyst denitration apparatus to simplify a constitutive facility around the incinerator and to keep an incinerator height low while preventing a combustion failure and can reduce nitrogen oxide concentration in the incinerator to 40 ppm or less, preferably to 20 ppm or less, while restraining the rising of blue smoke from a chimney.SOLUTION: Secondary combustion air is blown into the incinerator to completely burn unburnt gas, and then aqueous ammonia or urea water is mixed into a sodium hydroxide solution in piping and blown into the incinerator together with the sodium hydroxide solution in a state of stripping ammonia.

Description

本発明は、廃棄物焼却炉における高効率の炉内脱硝方法及び炉内脱硝装置に関する。   The present invention relates to a highly efficient in-furnace denitration method and in-furnace denitration apparatus in a waste incinerator.

従来、廃棄物焼却炉から発生する窒素酸化物（ＮＯｘ）を低減する方法として、燃焼により窒素酸化物の発生を抑制する方法が知られているが、燃焼により窒素酸化物の発生を抑制する方法は５０ｐｐｍが限界である。   Conventionally, as a method for reducing nitrogen oxide (NOx) generated from a waste incinerator, a method for suppressing generation of nitrogen oxide by combustion is known, but a method for suppressing generation of nitrogen oxide by combustion 50 ppm is the limit.

また、他の方法として、焼却炉内にアンモニア水や尿素水等の還元剤を吹込む無触媒脱硝法が知られており、この方法によればアンモニア水或いは尿素水を大量に吹込めば窒素酸化物の高い除去が可能であるものの、過剰な薬剤の吹込みは塩化アンモニウム発生の原因となり、煙突から紫煙を発生させる。   As another method, there is known a non-catalytic denitration method in which a reducing agent such as ammonia water or urea water is blown into an incinerator. According to this method, if a large amount of ammonia water or urea water is blown, nitrogen is injected. Although high oxide removal is possible, excessive chemical blowing causes ammonium chloride generation, generating purple smoke from the chimney.

そこで、従来の廃棄物焼却施設（図３参照）では、焼却炉１内にアンモニア水又は尿素水を、紫煙の原因となる塩化アンモニウムが発生しないよう、１当量程度吹込み、焼却炉１からの窒素酸化物濃度を６０〜８０ｐｐｍに抑制した後、触媒脱硝装置２で規制値以下（例えば４０ｐｐｍ）に低減している。即ち、焼却炉１内での脱硝効率が低いため、焼却炉１から発生する窒素酸化物濃度の規制値が厳しい場合には触媒脱硝装置２が必要となるが、触媒脱硝装置２に使用される低温触媒が非常に高価であることと、アンモニア供給設備等が必要なため、設備が複雑かつ高価になる。また、アンモニア水や尿素水を吹込む位置では、未だ窒素酸化物の中間生成物であるシアン化水素（ＨＣＮ）が存在しており、アンモニアはシアン化水素と反応しないため、窒素酸化物の生成反応も進んでいる。また、アンモニア水或いは尿素水が炉内でアンモニアガスに気化・分解する時間が必要であり、反応時間を十分にとろうとすると炉高が高くなり、炉高を低く抑えると反応時間が不足して窒素酸化物の除去効率が低下する。なお、図３において、３はエコノマイザ、４は減温塔、５はバグフィルタ、６は再加熱器、７は誘引送風機、８は煙突である。   Therefore, in a conventional waste incineration facility (see FIG. 3), ammonia water or urea water is blown into the incinerator 1 by about 1 equivalent so that ammonium chloride causing purple smoke is not generated. After suppressing the nitrogen oxide concentration to 60 to 80 ppm, the catalyst denitration device 2 reduces the concentration to below the regulation value (for example, 40 ppm). That is, since the denitration efficiency in the incinerator 1 is low, the catalyst denitration device 2 is required when the regulation value of the concentration of nitrogen oxides generated from the incinerator 1 is strict, but the catalyst denitration device 2 is used. Since the low-temperature catalyst is very expensive and requires an ammonia supply facility, the facility becomes complicated and expensive. In addition, hydrogen cyanide (HCN) that is an intermediate product of nitrogen oxide still exists at the position where ammonia water or urea water is blown, and ammonia does not react with hydrogen cyanide. Yes. In addition, it takes time for ammonia water or urea water to vaporize and decompose into ammonia gas in the furnace, and if the reaction time is taken sufficiently, the furnace height becomes high, and if the furnace height is kept low, the reaction time becomes insufficient. Nitrogen oxide removal efficiency decreases. In FIG. 3, 3 is an economizer, 4 is a temperature reducing tower, 5 is a bag filter, 6 is a reheater, 7 is an induction fan, and 8 is a chimney.

そこで、図２に示すように、炉内での窒素酸化物の生成を低減し、下流側に触媒脱硝装置を用いることなく排ガスを浄化可能にする排ガス処理方法として、焼却炉の燃焼ゾーンに水酸化ナトリウムの水溶液を吹込み、窒素酸化物の中間生成物であるシアン化水素（ＨＣＮ）をトラップした後、２次空気を吹込み完全燃焼させ、その後、アンモニア水又は尿素水を吹込んで窒素酸化物を除去する方法が開示されている（特許文献１）。なお、図２において、図３と同様の構成部分に同符号を付している。   Therefore, as shown in FIG. 2, as an exhaust gas treatment method that reduces the generation of nitrogen oxides in the furnace and makes it possible to purify the exhaust gas without using a catalytic denitration device on the downstream side, water is added to the combustion zone of the incinerator. Blowing in an aqueous solution of sodium oxide and trapping hydrogen cyanide (HCN), which is an intermediate product of nitrogen oxides, blowing secondary air to complete combustion, and then blowing ammonia water or urea water into nitrogen oxides. A removal method is disclosed (Patent Document 1). In FIG. 2, the same components as those in FIG. 3 are denoted by the same reference numerals.

この方法によれば、水酸化ナトリウムの水溶液とアンモニア水又は尿素水を別々に吹込むため窒素酸化物の除去効率は高いが、配管、ノズルがそれぞれに必要となり、炉回りの構成設備が複雑になる。   According to this method, an aqueous solution of sodium hydroxide and ammonia water or urea water are separately blown, so that the removal efficiency of nitrogen oxides is high. However, piping and nozzles are required for each, and the components around the furnace are complicated. Become.

また、上記と同様に、アンモニア水或いは尿素水が炉内でアンモニアガスに気化・分解する時間が必要であり、反応時間を十分にとろうとすると炉高が高くなり、炉高を低く抑えると反応時間が不足して窒素酸化物の除去効率が低下するという問題が尚残る。   Similarly to the above, it takes time for ammonia water or urea water to vaporize and decompose into ammonia gas in the furnace, and if the reaction time is taken sufficiently, the furnace height becomes high, and if the furnace height is kept low, the reaction will occur. There still remains a problem that the efficiency of removing nitrogen oxides decreases due to insufficient time.

さらに、炉内での均一な分散と攪拌混合が必要なため、水酸化ナトリウム水溶液及びアンモニア水又は尿素水をそれぞれ希釈して量を増やして吹込む必要があるが、水分が増えるため排ガス量が増え、炉負荷の低いときには炉内温度の低下につながり、燃焼不良となる場合もあり得る。   Furthermore, since uniform dispersion and stirring and mixing are required in the furnace, it is necessary to dilute the sodium hydroxide aqueous solution and ammonia water or urea water, respectively, and increase the amount to be injected. When the furnace load is low, the temperature inside the furnace is lowered, and combustion failure may occur.

特開２００４−２０１５９号公報JP 2004-20159 A

上記従来技術の問題点に鑑み、本発明は、触媒脱硝装置を省略でき、炉回りの構成設備をより簡素化することができ、燃焼不良も防止しつつ、炉高を低く抑えて、煙突からの紫煙の発生を抑制しつつ焼却炉内で窒素酸化物濃度を４０ｐｐｍ以下、望ましくは２０ｐｐｍ以下に低減し得る炉内脱硝方法及び炉内脱硝装置を提供することを主たる目的とする。   In view of the above-mentioned problems of the prior art, the present invention can omit the catalyst denitration device, can further simplify the equipment around the furnace, and prevent the combustion failure, while keeping the furnace height low, from the chimney. The main object of the present invention is to provide an in-furnace denitration method and an in-furnace denitration apparatus capable of reducing the nitrogen oxide concentration in an incinerator to 40 ppm or less, preferably 20 ppm or less while suppressing the generation of purple smoke.

上記目的を達成するため、本発明に係る焼却炉の炉内脱硝方法は、焼却炉内に２次燃焼空気を吹込んで未燃ガスを完全燃焼させた後、水酸化ナトリウム水溶液にアンモニア水又は尿素水を配管内で混合してアンモニアをストリッピングした状態で水酸化ナトリウム水溶液とともに炉内に吹込むことを特徴とする。   To achieve the above object, the in-furnace denitration method for an incinerator according to the present invention blows secondary combustion air into the incinerator to completely burn unburned gas, and then adds aqueous ammonia or urea to an aqueous sodium hydroxide solution. It is characterized in that water is mixed in a pipe and ammonia is stripped and blown into a furnace together with an aqueous sodium hydroxide solution.

また、本発明に係る焼却炉の炉内脱硝装置は、２次燃焼空気導入部と、水酸化ナトリウム水溶液を供給する第１配管と、アンモニア水又は尿素水を供給する第２配管と、前記第１配管内を供給される水酸化ナトリウム水溶液と第２配管内を供給されるアンモニア水又は尿素水を混合しアンモニアガスをストリッピングさせて水酸化ナトリウム水溶液とともに焼却炉の前記２次燃焼空気導入部の下流側に供給し炉内に吹込む第３配管と、を備えることを特徴とする。   An in-furnace denitration apparatus for an incinerator according to the present invention includes a secondary combustion air introduction section, a first pipe for supplying a sodium hydroxide aqueous solution, a second pipe for supplying ammonia water or urea water, The secondary combustion air introduction part of the incinerator of the incinerator is mixed with the sodium hydroxide aqueous solution by mixing the aqueous solution of sodium hydroxide supplied in one pipe with the ammonia water or urea water supplied in the second pipe and stripping ammonia gas. And a third pipe which is supplied to the downstream side and blown into the furnace.

前記第３配管内を加熱してアンモニアガスのストリッピングを促進する加熱装置を更に備えることが好ましい。   It is preferable to further include a heating device that heats the inside of the third pipe to promote the stripping of ammonia gas.

本発明によれば、アンモニア水又は尿素水を高アルカリの水酸化ナトリウム水溶液に配管内で混合して炉内に吹込むことにより、炉内吹込み前の配管中でアンモニアがストリッピングして気体となるため、炉内での反応時間を短縮でき、高い窒素酸化物除去率が得られる。   According to the present invention, ammonia water or urea water is mixed with a highly alkaline aqueous sodium hydroxide solution in a pipe and blown into the furnace, so that ammonia is stripped in the pipe before blowing into the furnace to form a gas. Therefore, the reaction time in the furnace can be shortened, and a high nitrogen oxide removal rate can be obtained.

また、吹込み口が一つで済むため炉回りの構成設備を簡素化できるし、アンモニア水又は尿素水と水酸化ナトリウム水溶液とを一つの吹込み口から供給するため、炉内で均一に分散、攪拌混合するために必要な希釈水量を減らすことができ、燃焼不良を抑制することができる。   Moreover, since only one inlet is required, the equipment around the furnace can be simplified, and ammonia water or urea water and sodium hydroxide aqueous solution are supplied from a single inlet, so that they are uniformly dispersed in the furnace. The amount of dilution water required for stirring and mixing can be reduced, and poor combustion can be suppressed.

また、吹込み前の配管中でアンモニアがストリッピングして気体となっているため、炉内への吹込み直後に気体アンモニアが炉内を上昇することにより、液体の水酸化ナトリウムが気体アンモニアより先にＨＣｌと反応してＨＣｌを除去するので、紫煙の原因となる塩化アンモニウムの発生を抑制することができる。   In addition, since ammonia is stripped in the pipe before being blown into a gas, the gaseous ammonia rises in the furnace immediately after being blown into the furnace, so that liquid sodium hydroxide is more than gaseous ammonia. Since it reacts with HCl first to remove HCl, generation of ammonium chloride that causes purple smoke can be suppressed.

また、窒素酸化物の中間生成物であるシアン化水素（ＨＣＮ）を水酸化ナトリウムで除去し、窒素酸化物については配管内で気化したアンモニアガスと反応することで、８０％以上の窒素酸化物除去が可能となる。   In addition, hydrogen cyanide (HCN), which is an intermediate product of nitrogen oxide, is removed with sodium hydroxide. Nitrogen oxide reacts with ammonia gas vaporized in the pipe, thereby removing 80% or more of nitrogen oxide. It becomes possible.

本発明に係る炉内脱硝装置を含む廃棄物焼却施設を示す概略構成図である。It is a schematic block diagram which shows the waste incineration facility containing the in-furnace denitration apparatus which concerns on this invention. 従来の廃棄物焼却施設を示す概略構成図である。It is a schematic block diagram which shows the conventional waste incineration facility. 従来の他の廃棄物焼却施設を示す概略構成図である。It is a schematic block diagram which shows the other conventional waste incineration facility.

本発明について、以下、図１を参照しつつ説明する。なお、図１は焼却炉１を含む焼却設備を示し、３はエコノマイザ、４は減温塔、５はバグフィルタ、７は誘引送風機、８は煙突である。焼却炉１は、ストーカー式焼却炉を例示している。ストーカー式焼却炉の基本構造は周知であり、従来構造の詳細については説明を省略する。   The present invention will be described below with reference to FIG. FIG. 1 shows incineration equipment including an incinerator 1, 3 is an economizer, 4 is a temperature reducing tower, 5 is a bag filter, 7 is an induction fan, and 8 is a chimney. The incinerator 1 illustrates a stalker type incinerator. The basic structure of the stalker-type incinerator is well known, and the details of the conventional structure are omitted.

焼却炉１には、２次燃焼空気導入部１０と、水酸化ナトリウム水溶液を供給する第１配管１１と、アンモニア水又は尿素水を供給する第２配管１２と、第１配管１１内を供給される水酸化ナトリウム水溶液と第２配管１２内を供給されるアンモニア水又は尿素水を混合しアンモニアガスをストリッピングさせて水酸化ナトリウム水溶液とともに焼却炉の２次燃焼空気導入部１０の下流側に供給し炉内に吹込む第３配管１３と、が備えられている。   The incinerator 1 is supplied with a secondary combustion air introduction unit 10, a first pipe 11 that supplies an aqueous sodium hydroxide solution, a second pipe 12 that supplies ammonia water or urea water, and the inside of the first pipe 11. Aqueous sodium hydroxide solution and ammonia water or urea water supplied in the second pipe 12 are mixed, and ammonia gas is stripped and supplied to the downstream side of the secondary combustion air introduction part 10 of the incinerator together with the sodium hydroxide aqueous solution. And a third pipe 13 for blowing into the furnace.

第３配管１３には、第３配管１３内を加熱してアンモニアガスのストリッピングを促進する加熱装置１４を更に備えてもよい。加熱装置１４は、熱交換器やヒータ等で構成することができる。第３配管１３の先端部には、液体を吹込むためのノズル（図示せず。）が装着される。   The third pipe 13 may further include a heating device 14 that heats the inside of the third pipe 13 and promotes stripping of ammonia gas. The heating device 14 can be composed of a heat exchanger, a heater, or the like. A nozzle (not shown) for injecting liquid is attached to the tip of the third pipe 13.

上記構成の焼却炉１において、ストーカー上での廃棄物燃焼中に、焼却炉１の２次燃焼ゾーンに設けられた２次燃焼空気導入部１０から２次燃焼空気を炉内に吹込み、未燃ガスを完全燃焼させる。   In the incinerator 1 configured as described above, during combustion of waste on the stalker, secondary combustion air is blown into the furnace from the secondary combustion air introduction unit 10 provided in the secondary combustion zone of the incinerator 1. Burn the fuel gas completely.

第１配管１１内を水酸化ナトリウム水溶液が供給され、第２配管１２内をアンモニア水又は尿素水が供給される。第１配管１１と第２配管１２との接合部で水酸化ナトリウム水溶液とアンモニア水又は尿素水とが混合し、第３配管１３内を供給される。   A sodium hydroxide aqueous solution is supplied through the first pipe 11, and ammonia water or urea water is supplied through the second pipe 12. A sodium hydroxide aqueous solution and ammonia water or urea water are mixed at the joint portion between the first pipe 11 and the second pipe 12, and the inside of the third pipe 13 is supplied.

第３配管１３内でアンモニア水又は尿素水と水酸化ナトリウム水溶液とを混合させることで、いわゆるアンモニアのストリッピングにより、第３配管１３内でアンモニウムイオンと水酸化物イオンとが反応し、水とアンモニアガスとが生成する。水酸化ナトリウム水溶液は、アンモニア水又は尿素水よりも多く供給され、アンモニアストリッピング反応で消費されなかった水酸化ナトリウム水溶液は、そのまま第３配管１３から炉内に吹込まれる。   By mixing ammonia water or urea water and sodium hydroxide aqueous solution in the third pipe 13, ammonium ions and hydroxide ions react in the third pipe 13 by so-called ammonia stripping, and water and Ammonia gas is produced. The sodium hydroxide aqueous solution is supplied more than the ammonia water or urea water, and the sodium hydroxide aqueous solution that has not been consumed in the ammonia stripping reaction is blown into the furnace as it is from the third pipe 13.

このように第３配管１３内でアンモニアをガス化させた状態にして炉内に吹込むことで、アンモニアガスを外部に放散させることなく炉内に導入できる。すなわち、アンモニア水（又は尿素水）を水酸化ナトリウム水溶液と貯槽等で混合するとアンモニアがストリッピングして気体として放散してしまうが、焼却炉１に接続した第３配管１３内で混合すればストリッピングしたアンモニアガスを逃がさずに炉内に吹込み可能である。   Thus, ammonia gas can be introduced into the furnace without being diffused to the outside by injecting ammonia into the furnace in a state of being gasified in the third pipe 13. That is, when ammonia water (or urea water) is mixed with a sodium hydroxide aqueous solution in a storage tank or the like, ammonia is stripped and diffused as a gas, but if mixed in the third pipe 13 connected to the incinerator 1, the ammonia is stripped. The ripped ammonia gas can be blown into the furnace without escaping.

また、第３配管１３内では水酸化ナトリウム水溶液とアンモニアガスとが混合しており、第３配管１３から炉内へ吹込み直後、アンモニアガスは燃焼排ガスとともに炉内を上昇し、水酸化ナトリウム水溶液はアンモニアガスの下層側（燃焼排ガスの上流側）で炉内の燃焼ガス中に存在する塩化水素（ＨＣｌ）、硫黄酸化物（ＳＯｘ）と反応してこれらを除去する。従って、燃焼ガス中の塩化水素は、アンモニアガスと反応するより前に、水酸化ナトリウムと反応して除去されるので、紫煙の原因となる塩化アンモニウムの生成が抑制される。また、炉内に吹込まれた水酸化ナトリウムは、シアン化水素（ＨＣＮ）とも反応してこれを除去する。窒素酸化物の中間生成物であるシアン化水素が除去されるため、新たに窒素酸化物の生成が抑制され、窒素酸化物濃度が低減され得る。   Moreover, the sodium hydroxide aqueous solution and ammonia gas are mixed in the third pipe 13, and immediately after being blown into the furnace from the third pipe 13, the ammonia gas rises in the furnace together with the combustion exhaust gas, and the sodium hydroxide aqueous solution Reacts with hydrogen chloride (HCl) and sulfur oxide (SOx) present in the combustion gas in the furnace on the lower layer side of the ammonia gas (upstream side of the combustion exhaust gas) to remove them. Therefore, hydrogen chloride in the combustion gas is removed by reacting with sodium hydroxide before reacting with the ammonia gas, so that generation of ammonium chloride that causes purple smoke is suppressed. Also, the sodium hydroxide blown into the furnace reacts with hydrogen cyanide (HCN) to remove it. Since hydrogen cyanide, which is an intermediate product of nitrogen oxide, is removed, generation of nitrogen oxide is newly suppressed, and the concentration of nitrogen oxide can be reduced.

第３配管１３から炉内に吹込まれたアンモニアガスは、炉内で窒素酸化物（ＮＯｘ）を窒素ガスに分解する。上記のように塩化水素が水酸化ナトリウムによって低減又は除去されているため、塩化アンモニウムの発生を危惧することなくアンモニアガスを過剰に吹込むことができるので、窒素酸化物濃度をいっそう低減させることができる。   The ammonia gas blown into the furnace from the third pipe 13 decomposes nitrogen oxide (NOx) into nitrogen gas in the furnace. Since hydrogen chloride is reduced or removed by sodium hydroxide as described above, ammonia gas can be blown in excess without concern about the generation of ammonium chloride, so that the nitrogen oxide concentration can be further reduced. it can.

第３配管１３の焼却炉１への取付位置、即ち吹込み位置は、焼却炉１の炉内温度が８５０〜９５０℃の温度域が好ましい。一般に無触媒脱硝の効果があるのは７５０〜９００℃域とされているが、実機試験では温度が低いと窒素酸化物の除去率が低く、尿素の吹込み位置の温度は８００〜９５０℃域が適正であった。なお、１０００℃以上の領域にアンモニアを吹込むと、アンモニアが酸化分解して窒素酸化物が発生する。   The attachment position of the third pipe 13 to the incinerator 1, that is, the blowing position, is preferably in the temperature range where the in-furnace temperature of the incinerator 1 is 850 to 950 ° C. In general, the effect of non-catalytic denitration is in the range of 750 to 900 ° C. However, in the actual machine test, if the temperature is low, the nitrogen oxide removal rate is low, and the temperature at the urea blowing position is in the range of 800 to 950 ° C. Was appropriate. In addition, when ammonia is blown into a region of 1000 ° C. or higher, ammonia is oxidized and decomposed to generate nitrogen oxides.

第１配管１１を通じて供給される水酸化ナトリウム水溶液の供給量は、一定とすることができるが、塩化水素濃度の変動が大きい場合は、焼却炉１の出口付近にレーザ式ガス分析計を設置して排ガス中の塩化水素濃度を検出し、塩化水素濃度が設定値以下になるように水酸化ナトリウム水溶液の供給量（流量）を調整することができる。また、煙突８又は焼却炉１の出口付近に、排ガス中の窒素酸化物濃度を検出する検出器を設置し、その検出値が所定値以下になるように、水酸管ナトリウム水溶液に混合させる尿素水（又はアンモニア水）の供給量、即ち、第２配管１２の流量を制御することができる。   The amount of sodium hydroxide aqueous solution supplied through the first pipe 11 can be constant, but if the fluctuation of the hydrogen chloride concentration is large, a laser gas analyzer is installed near the exit of the incinerator 1. Thus, the hydrogen chloride concentration in the exhaust gas is detected, and the supply amount (flow rate) of the sodium hydroxide aqueous solution can be adjusted so that the hydrogen chloride concentration is below the set value. Also, a detector that detects the concentration of nitrogen oxides in the exhaust gas is installed near the exit of the chimney 8 or the incinerator 1, and urea mixed with the aqueous sodium hydroxide tube so that the detected value is below a predetermined value. The supply amount of water (or ammonia water), that is, the flow rate of the second pipe 12 can be controlled.

上記のようにして、窒素酸化物、シアン化水素、塩化水素、硫黄酸化物が除去された燃焼排ガスは、エコノマイザ３、減温塔４、バグフィルタ５を経て、煙突８から大気に放出される。   The combustion exhaust gas from which nitrogen oxides, hydrogen cyanide, hydrogen chloride, and sulfur oxides are removed as described above is discharged from the chimney 8 to the atmosphere via the economizer 3, the temperature reducing tower 4, and the bag filter 5.

上記の説明から明らかなように、本発明によれば、アンモニア又は尿素を過剰に吹込めることと、水酸化ナトリウム自身のシアン化水素除去に伴う窒素酸化物濃度低減効果から２０ｐｐｍ以下にまで窒素酸化物濃度を低減することができ、塩化アンモニウムの生成を無くして紫煙の発生を防ぐこともできる。しかも、配管中でアンモニアを気体にして炉内に吹込むため、窒素酸化物との反応が早まり、炉高を低く抑えることができる。吹込み口を一つにできるため炉回りの構成設備を簡略化できる。水酸化ナトリウムとアンモニア水（又は尿素水）を一つの吹込み口から供給するため、炉内で均一に分散、攪拌混合するために必要な希釈水量を減らすことができ、燃焼不良を抑制することができる。また、水酸化ナトリウム水溶液の焼却炉内への吹込みにより既知の通り塩化水素、硫黄酸化物を除去できるため、エコノマイザの低温腐食抑制、ダイオキシン類の再合成抑制効果が得られる。さらに、触媒脱硝装置が不要となり、再加熱も不要なことから、蒸気タービンへの供給蒸気量が増え、発熱効率が向上する等の優れた効果を発揮し得る。   As is clear from the above description, according to the present invention, the nitrogen oxide concentration is reduced to 20 ppm or less from the excessive effect of blowing ammonia or urea and the nitrogen oxide concentration reduction effect associated with the removal of hydrogen cyanide of sodium hydroxide itself. The generation of ammonium chloride can be eliminated and the generation of purple smoke can be prevented. And since ammonia is made into gas in piping and it blows in in a furnace, reaction with a nitrogen oxide is accelerated | stimulated and furnace height can be restrained low. Since there is only one inlet, the equipment around the furnace can be simplified. Since sodium hydroxide and ammonia water (or urea water) are supplied from a single inlet, the amount of diluting water required to uniformly disperse and stir and mix in the furnace can be reduced, and combustion failure can be suppressed. Can do. Moreover, since hydrogen chloride and sulfur oxide can be removed as is known by blowing sodium hydroxide aqueous solution into the incinerator, the low temperature corrosion suppression of the economizer and the resynthesis suppression of dioxins can be obtained. Furthermore, since a catalyst denitration apparatus is not required and reheating is not required, excellent effects such as an increase in the amount of steam supplied to the steam turbine and an improvement in heat generation efficiency can be achieved.

１ 焼却炉
１０ ２次燃焼空気導入部
１１ 第１配管
１２ 第２配管
１３ 第３配管
１４ 加熱装置
DESCRIPTION OF SYMBOLS 1 Incinerator 10 Secondary combustion air introduction part 11 1st piping 12 2nd piping 13 3rd piping 14 Heating apparatus

Claims (3)

焼却炉内に２次燃焼空気を吹込んで未燃ガスを完全燃焼させた後、水酸化ナトリウム水溶液にアンモニア水又は尿素水を配管内で混合してアンモニアをストリッピングした状態で水酸化ナトリウム水溶液とともに炉内に吹込むことを特徴とする焼却炉内の脱硝方法。   After the secondary combustion air is blown into the incinerator to completely burn the unburned gas, ammonia water or urea water is mixed with the sodium hydroxide aqueous solution in the pipe and the ammonia is stripped together with the sodium hydroxide aqueous solution. A denitration method in an incinerator characterized by blowing into the furnace. ２次燃焼空気導入部と、水酸化ナトリウム水溶液を供給する第１配管と、アンモニア水又は尿素水を供給する第２配管と、前記第１配管内を供給される水酸化ナトリウム水溶液と第２配管内を供給されるアンモニア水又は尿素水を混合しアンモニアガスをストリッピングさせて水酸化ナトリウム水溶液とともに焼却炉の前記２次燃焼空気導入部の下流側に供給し炉内に吹込む第３配管と、を備えることを特徴とする焼却炉の炉内脱硝装置。   A secondary combustion air introduction section, a first pipe for supplying a sodium hydroxide aqueous solution, a second pipe for supplying ammonia water or urea water, a sodium hydroxide aqueous solution and a second pipe supplied in the first pipe A third pipe for mixing ammonia water or urea water supplied in the interior, stripping ammonia gas, and supplying it to the downstream side of the secondary combustion air introduction part of the incinerator together with the sodium hydroxide aqueous solution and blowing it into the furnace; An in-furnace denitration apparatus for an incinerator. 前記第３配管内を加熱してアンモニアガスのストリッピングを促進する加熱装置を更に備えることを特徴とする請求項２に記載の焼却炉の炉内脱硝装置。
The in-furnace denitration apparatus for an incinerator according to claim 2, further comprising a heating device that heats the inside of the third pipe to promote stripping of ammonia gas.
JP2012001663A 2012-01-06 2012-01-06 Method and apparatus for denitration in incinerator Pending JP2013142481A (en)

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CN103438355A (en) * 2013-08-19 2013-12-11 江苏新中环保股份有限公司 Ammonia solution conveying device
CN106110863A (en) * 2016-08-08 2016-11-16 中昊黑元化工研究设计院有限公司 A kind of boiler with tailed method of denitration
JP6286517B1 (en) * 2016-12-07 2018-02-28 株式会社プランテック Incinerator
CN111396892A (en) * 2020-04-12 2020-07-10 林仲谋 Industrial waste treatment incineration tail gas denitration device and application method thereof

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JP2003275540A (en) * 2002-03-26 2003-09-30 Taiheiyo Cement Corp Method for utilizing ammonia nitrogen in waste water
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US5058514A (en) * 1989-10-18 1991-10-22 Mozes Miriam S Process for controlling acid gas emissions in power plant flue gases
JP2003275540A (en) * 2002-03-26 2003-09-30 Taiheiyo Cement Corp Method for utilizing ammonia nitrogen in waste water
JP2009103381A (en) * 2007-10-24 2009-05-14 Takuma Co Ltd Noncatalytic denitration method and noncatalytic denitration system

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103438355A (en) * 2013-08-19 2013-12-11 江苏新中环保股份有限公司 Ammonia solution conveying device
CN103438355B (en) * 2013-08-19 2015-12-16 江苏新中环保股份有限公司 A kind of ammonia spirit feedway
CN106110863A (en) * 2016-08-08 2016-11-16 中昊黑元化工研究设计院有限公司 A kind of boiler with tailed method of denitration
CN106110863B (en) * 2016-08-08 2018-12-04 中昊黑元化工研究设计院有限公司 A kind of boiler with tailed method of denitration
JP6286517B1 (en) * 2016-12-07 2018-02-28 株式会社プランテック Incinerator
JP2018091587A (en) * 2016-12-07 2018-06-14 株式会社プランテック Incineration equipment
CN111396892A (en) * 2020-04-12 2020-07-10 林仲谋 Industrial waste treatment incineration tail gas denitration device and application method thereof

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