JP3380046B2 - Wet exhaust gas desulfurization method and apparatus - Google Patents
Wet exhaust gas desulfurization method and apparatusInfo
- Publication number
- JP3380046B2 JP3380046B2 JP15621394A JP15621394A JP3380046B2 JP 3380046 B2 JP3380046 B2 JP 3380046B2 JP 15621394 A JP15621394 A JP 15621394A JP 15621394 A JP15621394 A JP 15621394A JP 3380046 B2 JP3380046 B2 JP 3380046B2
- Authority
- JP
- Japan
- Prior art keywords
- exhaust gas
- desulfurization
- spray
- tower
- spray nozzle
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
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- Treating Waste Gases (AREA)
- Gas Separation By Absorption (AREA)
Description
【０００１】[0001]
【産業上の利用分野】本発明は、湿式排ガス脱硫方法お
よび装置に係り、特に吸収液スプレーノズル装置の改良
により脱硫性能を向上させ装置の小型化と運転動力費の
低減を可能とした湿式排ガス脱硫方法および装置に関す
る。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wet exhaust gas desulfurization method and apparatus, and more particularly, to a wet exhaust gas capable of improving desulfurization performance by improving an absorption liquid spray nozzle device to downsize the device and reduce operating cost. The present invention relates to a desulfurization method and device.
【０００２】[0002]
【従来の技術】火力発電所等において、化石燃料の燃焼
に伴って発生する排煙中の硫黄酸化物、中でも特に二酸
化硫黄（ＳＯ2)は、大気汚染・酸性雨等の地球的環境問
題の主原因の一つである。このため、排煙中からＳＯ2
を除去する排煙脱硫法の研究および脱硫装置の開発は極
めて重要な課題となっている。2. Description of the Related Art Sulfur oxides, especially sulfur dioxide (SO 2 ), in flue gas produced by burning fossil fuels in thermal power plants, etc., are particularly harmful to global environmental problems such as air pollution and acid rain. It is one of the main causes. For this reason, SO 2
Research on flue gas desulfurization method for removing methane and development of desulfurization equipment have become extremely important issues.
【０００３】上記脱硫法としては、最近低コストでシス
テムが簡単な簡易型の乾式脱硫装置の開発が進められて
いるが、脱硫率がせいぜい７０〜８０％と低いこともあ
り、まだ湿式法が主流を占めている。この湿式法には、
吸収剤にソーダ化合物を用いるソーダ法、カルシウム化
合物を用いるカルシウム法およびマグネシウム化合物を
用いるマグネシウム法等がある。このうち、ソーダ法は
吸収剤とＳＯ2 との反応性に優れている反面、使用する
ソーダ類が非常に高価である。このため、発電用の大型
ボイラ等の排煙脱硫装置には、比較的安価な炭酸カルシ
ウム等のカルシウム化合物を用いる方法が最も多く採用
されている。As the desulfurization method, recently, a simple dry desulfurization apparatus having a low cost and a simple system is being developed, but the desulfurization rate is as low as 70 to 80% at most, and therefore the wet method is still used. It occupies the mainstream. This wet method includes
There are a soda method using a soda compound as an absorbent, a calcium method using a calcium compound, and a magnesium method using a magnesium compound. Among these, the soda method is excellent in reactivity between the absorbent and SO 2 , but the soda used is very expensive. For this reason, a method using a relatively inexpensive calcium compound such as calcium carbonate is most often used for a flue gas desulfurization device such as a large-scale boiler for power generation.
【０００４】このカルシウム化合物を吸収液として用い
る脱硫システムは、気液接触方法の違いによりスプレー
方式、濡れ壁方式およびバブリング方式の３種類に大別
される。各方式ともそれぞれ特徴を有しているが、実績
が多く信頼性の高いスプレー方式が世界的にも多く採用
されている。このスプレー方式の脱硫システムとして
は、従来から排ガスの冷却・除塵を行なう冷却塔、吸収
液を噴霧して排ガス中のＳＯ2 と反応させる吸収塔、吸
収塔で生成した亜硫酸カルシウムを酸化する酸化塔の３
塔で構成されていた。しかし、近年になって吸収塔に冷
却・酸化の機能を持たせた１塔型脱硫塔の開発が進み、
最近では１塔型脱硫システムがスプレー方式の主流にな
りつつある。Desulfurization systems using this calcium compound as an absorbing liquid are roughly classified into three types, a spray system, a wetting wall system and a bubbling system, depending on the difference in gas-liquid contact method. Although each method has its own characteristics, the spray method, which has a proven track record and is highly reliable, is widely used worldwide. As the spray-type desulfurization system, a cooling tower that conventionally cools and removes exhaust gas, an absorption tower that sprays an absorbing liquid to react with SO 2 in the exhaust gas, and an oxidation tower that oxidizes calcium sulfite generated in the absorption tower Of 3
It was composed of towers. However, in recent years, the development of a one-tower desulfurization tower in which the absorption tower has functions of cooling and oxidation has progressed,
Recently, the single tower desulfurization system is becoming the mainstream of the spray method.
【０００５】図９に従来技術のスプレー方式による１塔
型脱硫装置の一例を示す。１塔型の脱硫塔は、主に脱硫
塔本体１、入口ダクト２、出口ダクト３、スプレーノズ
ル４、吸収液の循環ポンプ５、循環タンク６、デミスタ
９等から構成される。スプレーノズル４は水平方向に複
数個、さらに高さ方向に複数段設置されており、通常各
段ごとに１台ずつ循環ポンプ５が設置される。スプレー
ノズル４の段数としては、一般に４〜１０段程度設置さ
れることが多いが、本図では簡略化のため４段で示して
いる。また、スプレーノズル４から噴霧され微粒化され
た吸収液の中で、液滴径の小さいものは排ガスに同伴さ
れるが、脱硫塔上部に設けられたデミスタ９によって回
収される。FIG. 9 shows an example of a one-tower type desulfurization apparatus using a conventional spray method. The one-tower type desulfurization tower is mainly composed of a desulfurization tower body 1, an inlet duct 2, an outlet duct 3, a spray nozzle 4, an absorption liquid circulation pump 5, a circulation tank 6, a demister 9 and the like. A plurality of spray nozzles 4 are installed in the horizontal direction and a plurality of stages in the height direction, and normally one circulation pump 5 is installed in each stage. Generally, the number of stages of the spray nozzle 4 is generally about 4 to 10, but in this figure, four stages are shown for simplification. Further, among the absorption liquids atomized by the spray nozzle 4 and atomized, those having a small droplet diameter are entrained in the exhaust gas, but are recovered by the demister 9 provided at the upper part of the desulfurization tower.
【０００６】デミスタ９は吸収塔内最上部または出口ダ
クト３内に設置される。図には示していないがボイラか
ら排出される排ガス２４は、入口ダクト２より脱硫塔本
体１に導入され、最終的には出口ダクト３より処理ガス
２５として排出される。この間、脱硫塔には循環ポンプ
５から送られる炭酸カルシウムを含んだ吸収液が、脱硫
塔内に配置されたスプレ配管１５に取付けられた複数の
スプレーノズル４から噴霧され、吸収液と排ガス２４の
気液接触が行なわれる。このとき吸収液は排ガス中のＳ
Ｏ2 を選択的に吸収し、重亜硫酸カルシウム（Ｃａ（Ｈ
ＳＯ3)2 ）を生成する。重亜硫酸カルシウムを生成した
吸収液は循環タンク６に溜まり、空気吹込み管８より導
入された空気を攪拌機７で循環タンク６内に均一に分散
させることにより、重亜硫酸カルシウムは酸化されて最
終的に石膏（ＣａＳＯ4)を生成する。炭酸カルシウム
（ＣａＣＯ3)および石膏が共存する循環タンク６内の吸
収液の一部は、循環ポンプ５によって再びスプレーノズ
ル４に送られる。The demister 9 is installed in the uppermost part of the absorption tower or in the outlet duct 3. Although not shown in the figure, the exhaust gas 24 discharged from the boiler is introduced into the desulfurization tower main body 1 through the inlet duct 2 and finally discharged as the process gas 25 through the outlet duct 3. During this time, the desulfurization tower receives the absorption liquid containing the calcium carbonate sent from the circulation pump 5 from the plurality of spray nozzles 4 attached to the spray pipe 15 arranged in the desulfurization tower, thereby absorbing the absorption liquid and the exhaust gas 24. Gas-liquid contact is made. At this time, the absorbing liquid is S in the exhaust gas.
It selectively absorbs O 2 and calcium bisulfite (Ca (H
SO 3) 2) to produce a. The absorbing liquid that produced calcium bisulfite is accumulated in the circulation tank 6, and the air introduced from the air blowing pipe 8 is uniformly dispersed in the circulation tank 6 by the stirrer 7, whereby the calcium bisulfite is oxidized and finally Generates gypsum (CaSO 4 ). A part of the absorption liquid in the circulation tank 6 in which calcium carbonate (CaCO 3 ) and gypsum coexist is sent to the spray nozzle 4 again by the circulation pump 5.
【０００７】従来、スプレーノズル４により吸収液を噴
霧して脱硫する場合、通常用いられている２〜３インチ
のスプレーノズル４では平均液滴径が２mm程度であり、
スプレーノズル４の間隔を通常１．５ｍ以上離してスプ
レーノズル４を配置していた。スプレーノズル４同士を
近づけて配置すると、液滴同士が干渉して液滴径が１mm
以下と小さくなり過ぎて、排ガス２４に同伴されて飛散
する液滴量が増加すると同時に脱硫性能も低下してい
た。このように平均液滴径が２mm程度の場合、スプレー
ノズル４の間隔を１．５ｍ以上に離す必要があるので必
然的にスプレー配管１５の段数は多くなり、塔高が高く
なる。そのため装置コストが高くなり、循環液を循環す
るポンプ５の消費動力も大きくなる欠点がある。したが
って、脱硫塔内でノズル配置の間隔を小さくし、いかに
脱硫塔をコンパクトにするかが大きな課題となる。Conventionally, in the case of desulfurizing by spraying the absorbing liquid by the spray nozzle 4, the average droplet diameter of the spray nozzle 4 of 2 to 3 inches which is usually used is about 2 mm,
Normally, the spray nozzles 4 are arranged with a space of 1.5 m or more between them. When the spray nozzles 4 are placed close to each other, the droplets interfere with each other and the droplet diameter is 1 mm.
It became too small as follows, and the amount of droplets entrained and scattered by the exhaust gas 24 increased, and at the same time, the desulfurization performance also deteriorated. As described above, when the average droplet diameter is about 2 mm, the spray nozzles 4 need to be spaced apart from each other by 1.5 m or more, so that the number of stages of the spray pipe 15 inevitably increases and the tower height increases. Therefore, there are disadvantages that the cost of the apparatus increases and the power consumption of the pump 5 that circulates the circulating liquid also increases. Therefore, how to make the desulfurization tower compact by reducing the interval of nozzle arrangement in the desulfurization tower becomes a major issue.
【０００８】[0008]
【発明が解決しようとする課題】通常、実機の脱硫塔で
用いられる２〜３インチのスプレーノズル４から噴霧さ
れる平均液滴径は２mm程度であり、液滴同士が干渉して
液滴径が小さくなり過ぎないようにスプレーノズル４の
間隔は１．５ｍ程度離して設置されていた。目標脱硫率
により必要液ガス比が決まり、液量が決まれば必要なス
プレーノズル４の個数が設定される。スプレーノズル４
の設置間隔が大きいほど、脱硫塔内のスプレ配管１５の
段数が多くなり、塔高も高くなるので循環液量を循環す
る循環ポンプ５の消費動力も増加する。スプレー塔で噴
霧された液滴径は通常の２〜３インチのスプレーノズル
４では２mm程度であり、液滴同士が干渉して液滴径が小
さくなるとミスト飛散量は増加し脱硫性能が低下するの
で、スプレーノズル４の間隔を広げていた。特にガス流
速を高速化すると、その傾向が著しい。また塔外の酸化
方式では、液中の亜硫酸濃度が高いのでスプレーノズル
４の間隔を近づけて液滴を干渉させると、液滴中のｐＨ
も下がり脱硫性能も低下していた。そのためにスプレー
ノズル４の間隔をある程度離す必要が生じたが、スプレ
ーノズル４の間隔を広げると塔内で必要なスプレ配管１
５の段数が増加するので望ましくない。また、スプレー
ノズル４の中心部分は液膜の抵抗が大きいのでとうして
もガスが偏流し脱硫性能も低下しやすく、また排ガス中
のダストの除塵性能も低下する問題点があった。したが
って、本発明の目的は、スプレーノズルの配置間隔を狭
くしても脱硫性能が低下しないように、コンパクトな脱
硫装置で高性能に脱硫することをができる湿式排ガス脱
硫方法および装置を提供することにある。Usually, the average droplet diameter sprayed from the 2-3 inch spray nozzle 4 used in the desulfurization tower of the actual machine is about 2 mm, and the droplets interfere with each other and thus the droplet diameter. The distance between the spray nozzles 4 was set to be about 1.5 m so as not to be too small. The required liquid-gas ratio is determined by the target desulfurization rate, and the required number of spray nozzles 4 is set when the liquid amount is determined. Spray nozzle 4
The larger the installation interval, the greater the number of stages of the spray pipe 15 in the desulfurization tower, and the higher the tower height. Therefore, the power consumption of the circulation pump 5 for circulating the circulating liquid amount also increases. The diameter of the droplets sprayed in the spray tower is about 2 mm in the ordinary 2-3 inch spray nozzle 4, and when the droplets interfere with each other and the droplet diameter becomes small, the amount of mist scattering increases and the desulfurization performance deteriorates. Therefore, the distance between the spray nozzles 4 was increased. Especially when the gas flow velocity is increased, the tendency is remarkable. Further, in the oxidation method outside the tower, since the sulfurous acid concentration in the liquid is high, if the distance between the spray nozzles 4 is reduced and the liquid droplets are interfered with each other, the pH in the liquid droplets is increased.
The desulfurization performance was also lowered. Therefore, it is necessary to separate the spray nozzles 4 from each other to some extent. However, if the spray nozzles 4 are widened, the spray pipe 1 required in the tower 1
This is not desirable because the number of stages of 5 increases. Further, since the resistance of the liquid film is large in the central portion of the spray nozzle 4, there is a problem that even if the gas is unevenly distributed, the desulfurization performance is likely to be deteriorated and the dust removal performance of the dust in the exhaust gas is also deteriorated. Therefore, an object of the present invention is to provide a wet exhaust gas desulfurization method and apparatus capable of performing high-performance desulfurization with a compact desulfurization device so that the desulfurization performance does not deteriorate even if the arrangement interval of the spray nozzles is narrowed. It is in.
【０００９】[0009]
【課題を解決するための手段】上記目的を達成するため
本願で特許請求する発明は以下のとおりである。
（１）硫黄酸化物含有排ガスを脱硫塔内に導入し、これ
にカルシウム系吸収液をスプレーノズルにより噴霧して
排ガス中の硫黄酸化物を吸収し、吸収した吸収液を吸収
液循環タンク内に収容し、循環タンク内の吸収液中に空
気を吹込んで液中の亜硫酸塩を酸化して石膏を生成させ
るとともに、循環タンク内の吸収液を前記スプレーノズ
ルに供給する湿式排ガス脱硫方法において、前記スプレ
ーノズルから噴霧される平均噴霧吸収液滴径を２．７mm
以上とし、かつ各ノズルの噴射口間隔を０．２５ｍ〜
１．１ｍの範囲として噴霧液滴どうしを衝突干渉させる
ことを特徴とする湿式排ガス脱硫方法。In order to achieve the above object, the invention claimed in the present application is as follows. (1) Sulfur oxide-containing exhaust gas is introduced into a desulfurization tower, and a calcium-based absorption liquid is sprayed on this by a spray nozzle to absorb the sulfur oxides in the exhaust gas, and the absorbed absorption liquid is placed in an absorption liquid circulation tank. accommodated, by blowing air to oxidize the sulfite in the solution with to produce gypsum in the absorbing liquid in the circulation tank, the wet flue gas desulfurization process which supplies the absorption liquid in the circulation tank to said spray nozzle, said Spray
-Average spray absorption droplet diameter sprayed from the nozzle is 2.7 mm
Above, and the injection port spacing of each nozzle is 0.25m ~
A wet exhaust gas desulfurization method, characterized in that spray droplets collide and interfere with each other in a range of 1.1 m.
【００１０】（２）上記（１）において、衝突干渉後の
噴霧液滴径が主として１．４mmないし２．２mmのもので
構成されることを特徴とする湿式排ガス脱硫方法。
（３）硫黄酸化物含有排ガスを導入する排ガス入口と処
理された排ガスを排出する排ガス出口とを有する脱硫塔
と、脱硫塔内に排ガス流れ方向に多段に配置されて脱硫
塔内に導入された排ガスにカルシウム系吸収液を噴霧す
るスプレーノズルと、脱硫塔内で噴霧され排ガス中の硫
黄酸化物を吸収した吸収液を収容する吸収液循環タンク
と、循環タンク内の吸収液をスプレーノズルに循環供給
する循環装置と、循環タンク内に酸化用空気を吹込む装
置とを備えた湿式排ガス脱硫装置において、前記スプレ
ーノズルの平均噴霧液滴径が２．７mm以上、スプレーノ
ズル口配置間隔が０．２５ｍないし１．１ｍとなるよう
にスプレーノズル部を構成したことを特徴とする湿式排
ガス脱硫装置。(2) A wet exhaust gas desulfurization method according to the above (1), characterized in that the spray droplet diameter after collision interference is mainly 1.4 mm to 2.2 mm. (3) A desulfurization tower having an exhaust gas inlet for introducing the exhaust gas containing sulfur oxides and an exhaust gas outlet for discharging the treated exhaust gas, and the desulfurization tower is arranged in multiple stages in the exhaust gas flow direction and introduced into the desulfurization tower. A spray nozzle that sprays a calcium-based absorption liquid into the exhaust gas, an absorption liquid circulation tank that stores the absorption liquid that has been absorbed in the desulfurization tower and has absorbed the sulfur oxides in the exhaust gas, and the absorption liquid in the circulation tank is circulated to the spray nozzle. A wet exhaust gas desulfurization apparatus comprising a supply circulation device and a device for blowing oxidizing air into a circulation tank,
-A wet exhaust gas desulfurization apparatus characterized in that the spray nozzle section is configured such that the average spray droplet diameter of the nozzle is 2.7 mm or more and the spray nozzle port arrangement interval is 0.25 m to 1.1 m.
【００１１】[0011]
【作用】平均液滴径を２．７mm以上にしてスプレーノズ
ルの間隔を０．２５〜１．１ｍに狭くすると、噴霧され
た液滴は脱硫塔内で液滴同士の衝突を繰り返す回数が増
加し、液滴は次第に小さくなり液滴の表面積は増加す
る。このような現象はＰＤＰＡ装置（レーザ式の粒径測
定装置（ドップラーレーザ計測装置）により容易に確認
できる。液滴平均径が１．４〜２．２mm程度にまで小さ
くなると、ガスに同伴されて飛散する液滴径も少なく単
位容積当たりの液滴反応表面積が増加し、液滴とガス中
のＳＯ2 ガスとの反応は促進される。従来の塔外酸化方
式では、液滴径が小さくなると液滴表面積が上がりｐＨ
が低下する条件では大幅に脱硫率が下がる。これに対し
て、塔内酸化方式である一塔型脱硫方式ではｐＨが４前
後まで低下しても脱硫性能はほとんど低下せず、液滴を
積極的に衝突させ液滴径をある程度小さくすることが望
ましい。また、流体解析プログラムにより液滴を噴霧し
た場合の脱硫塔内のガス流れを解析すると、スプレーノ
ズルからの噴霧による液膜の部分がガスの抵抗となるの
で、ガスはどうしてもスプレーノズルとスプレーノズル
の間を流れることになる。これに対して本発明を利用す
れば、スプレーノズルの間隔が狭くなるので塔内でのガ
スの偏流はほとんどなくなり、脱硫性能の向上とダスト
の除塵性能も大幅に向上することになる。When the average droplet diameter is 2.7 mm or more and the distance between the spray nozzles is narrowed to 0.25 to 1.1 m, the sprayed droplets increase the number of collisions between the droplets in the desulfurization tower. However, the droplet becomes smaller and the surface area of the droplet increases. Such a phenomenon can be easily confirmed by a PDPA device (laser type particle size measuring device (Doppler laser measuring device). When the average droplet size becomes as small as 1.4 to 2.2 mm, it is entrained in the gas. The diameter of droplets scattered is small and the surface area of droplet reaction per unit volume is increased to promote the reaction between droplets and SO 2 gas in the gas. Increased droplet surface area and pH
The desulfurization rate will be significantly reduced under the condition of decreasing. On the other hand, in the one-tower desulfurization method, which is an in-tower oxidation method, the desulfurization performance hardly decreases even when the pH drops to around 4, and the droplets are positively collided to reduce the droplet diameter to some extent. Is desirable. Also, when analyzing the gas flow in the desulfurization tower when liquid droplets are sprayed by the fluid analysis program, the liquid film part due to spraying from the spray nozzle becomes the resistance of the gas, so the gas is inevitably in the spray nozzle and the spray nozzle. It will flow through. On the other hand, if the present invention is used, the spacing between the spray nozzles is narrowed, so that the gas drift in the tower is almost eliminated, and the desulfurization performance and the dust removal performance are greatly improved.
【００１２】以上のような方法により、脱硫塔でのスプ
レーノズルの間隔を狭くするとスプレーノズルのスプレ
配管１５の段数が減るので、脱硫塔高が低くなり循環液
の循環ポンプの消費動力も低減ができ、脱硫性能および
脱塵性能も同時に改善できる。When the interval between the spray nozzles in the desulfurization tower is narrowed by the above method, the number of stages of the spray nozzle spray pipes 15 is reduced, so that the desulfurization tower height is lowered and the power consumption of the circulating fluid circulation pump is also reduced. It is possible to improve desulfurization performance and dust removal performance at the same time.
【００１３】[0013]
【実施例】本発明は、下記の実施例によって、さらに詳
細に説明されるが、下記の例で制限されるものではな
い。本発明の実施例を図１に示す。ＳＯ2 を含む燃焼排
ガス２４は塔側壁部の入口ダクト２から脱硫塔本体１に
入る。脱硫塔では循環ポンプ５から送られる炭酸カルシ
ウムを含んだ吸収液が、スプレ配管１５に設置された複
数のスプレーノズル４から噴霧される。ここで噴霧され
た吸収液と排ガス２４の気液接触により、ＳＯ2 ガスが
吸収されて吸収液は循環タンク６に落下する。この循環
タンク６では、空気吹込み管８から供給される空気を循
環タンク６の側壁に設置した攪拌機７により循環タンク
６内に均一に分散させることにより、循環タンク６内に
存在する重亜硫酸カルシウムは酸化され、最終的にＳＯ
2 は石膏（ＣａＳＯ4)として回収される。吸収液の一部
を回収系配管１４から抜き出して、石膏処理装置１２で
石膏は処理される。反応した石膏と当量の石灰石を石灰
石供給管１３より導入する。また、スプレーノズル４か
ら噴霧され微粒化された吸収液の中で、液滴径の小さい
ものは排ガスに同伴される。この液滴は脱硫塔内に設け
られたデミスタ９により回収される。ＳＯ2 ガスおよび
飛散ミストが除去された処理ガス２５は出口ダクト３か
ら図示していない煙突を通り系外に排出される。The present invention will be explained in more detail by the following examples, but it should not be construed as being limited thereto. An embodiment of the present invention is shown in FIG. The combustion exhaust gas 24 containing SO 2 enters the desulfurization tower main body 1 through an inlet duct 2 on the side wall of the tower. In the desulfurization tower, the absorption liquid containing calcium carbonate sent from the circulation pump 5 is sprayed from the plurality of spray nozzles 4 installed in the spray pipe 15. Due to gas-liquid contact between the sprayed absorption liquid and the exhaust gas 24, SO 2 gas is absorbed and the absorption liquid falls into the circulation tank 6. In this circulation tank 6, the air supplied from the air blowing pipe 8 is uniformly dispersed in the circulation tank 6 by the stirrer 7 installed on the side wall of the circulation tank 6, so that the calcium bisulfite existing in the circulation tank 6 is dispersed. Is oxidized and eventually SO
2 is recovered as gypsum (CaSO 4 ). A part of the absorbing liquid is extracted from the recovery system pipe 14, and the gypsum processing device 12 processes the gypsum. The reacted gypsum and the equivalent amount of limestone are introduced through the limestone supply pipe 13. Further, among the absorbing liquids atomized and sprayed from the spray nozzle 4, those having a small droplet diameter are entrained in the exhaust gas. The droplets are collected by the demister 9 provided in the desulfurization tower. The processing gas 25 from which the SO 2 gas and the scattered mist have been removed is discharged from the outlet duct 3 to the outside of the system through a stack (not shown).
【００１４】脱硫塔内のスプレ配管１５に設置されたス
プレーノズル４の間隔は、０．２５〜１．１ｍと従来法
より狭く設置されているので、噴霧された液滴（平均径
が２．７mm）の脱硫塔内で液滴同士の衝突を繰り返す回
数が増加し、液滴はある程度小さくなり液滴の表面積は
増加する。このような現象はＰＤＰＡ装置により容易に
確認できる。液滴径が１．４〜２．２mmとある程度小さ
くなると単位容積当たりの液滴反応表面積が増加し、液
滴とガス中のＳＯ2 ガスとの反応は促進されるので脱硫
率は向上することになる。また、このような液滴径では
飛散するミスト量もそれほど増加しない。従来の塔外酸
化方式では、液滴径が小さくなると液滴表面積が上がり
ｐＨが低下する条件では大幅に脱硫率が下がる。これに
対して、塔内酸化方式である一塔型脱硫方式ではｐＨが
４前後まで低下しても脱硫性能はほとんど低下せず、噴
霧液滴径を２．７mm以上にすればスプレーノズル４の間
隔を狭くして液滴同士を衝突させ、液滴径をある程度小
さくすることが望ましい。Since the distance between the spray nozzles 4 installed in the spray pipe 15 in the desulfurization tower is 0.25 to 1.1 m, which is narrower than that in the conventional method, sprayed droplets (having an average diameter of 2. The number of repetitions of collision of droplets in a 7 mm) desulfurization tower increases, the droplet becomes small to some extent, and the surface area of the droplet increases. Such a phenomenon can be easily confirmed by the PDPA device. When the diameter of the liquid droplet is 1.4 to 2.2 mm, it is possible to increase the desulfurization rate because the reaction surface area of the liquid droplet per unit volume increases and the reaction between the liquid droplet and SO 2 gas in the gas is promoted. become. Further, with such a droplet diameter, the amount of scattered mist does not increase so much. In the conventional extra-column oxidation method, the desulfurization rate is significantly reduced under the condition that the droplet surface area increases and the pH decreases as the droplet diameter decreases. On the other hand, in the one-tower type desulfurization method which is an in-tower oxidation method, the desulfurization performance hardly deteriorates even when the pH is lowered to around 4, and if the spray droplet diameter is 2.7 mm or more, the spray nozzle 4 It is desirable to reduce the diameter of the droplets to some extent by narrowing the interval and causing the droplets to collide with each other.
【００１５】このように本実施例によれば、スプレーノ
ズル４の間隔を大幅に低減できるのでスプレ配管１５の
段数が低減でき塔高を低くすることが可能となる。ま
た、液循環ポンプ５の動力費用も低減できる効果があ
る。図２には、横型の脱硫塔に適用した場合の実施例を
示す。横型反応塔の場合も同様の効果があるが、スプレ
ーノズル４の間隔を狭くするとガスに同伴されて飛散す
る液滴の液膜による捕集率も増加するので、この点から
も本実施例のようにスプレーノズル４の間隔を狭くする
ことは有効である。As described above, according to this embodiment, the distance between the spray nozzles 4 can be greatly reduced, so that the number of stages of the spray pipe 15 can be reduced and the tower height can be lowered. In addition, the power cost of the liquid circulation pump 5 can be reduced. FIG. 2 shows an embodiment when applied to a horizontal desulfurization tower. The same effect can be obtained in the case of a horizontal reaction tower, but if the distance between the spray nozzles 4 is narrowed, the collection rate of droplets entrained by the gas and scattered by the liquid film also increases. It is effective to reduce the distance between the spray nozzles 4 as described above.
【００１６】図３は、本発明におけるスプレ配管１５に
取付けたスプレーノズル４から噴霧される液滴とガスの
流れを示す図である。図４に示すような従来法では、ス
プレーノズル４の間隔が広いのでスプレーノズル４の中
心部と液滴と液滴が衝突する付近では液滴の密度が異な
るので、ガスの偏流が生じていた。すなわちガス流れ２
６はスプレーノズル４の付近を避けて偏流しながら塔内
を流れることになる。これに対して図３に示す本発明で
は、スプレーノズル４の間隔が従来法に比べ狭いので液
滴同士の干渉が非常に多くなり、液滴径は必然的に小さ
くなる。また、図３に示すように噴霧された液滴の密度
がほぼ均一となるので、ガス流れ２６は従来法のように
偏流を起こすことはない。このようにスプレーノズル４
の間隔を狭くすると液滴がある程度小さくなり性能面で
も、ガス流れの面でも有利となり、塔高もそれだけ低く
することができる。FIG. 3 is a diagram showing the flow of droplets and gas sprayed from the spray nozzle 4 attached to the spray pipe 15 of the present invention. In the conventional method as shown in FIG. 4, since the distance between the spray nozzles 4 is wide, the density of the liquid droplets is different in the central portion of the spray nozzle 4 and in the vicinity where the liquid droplets collide with each other, so that gas drift occurs. . Ie gas flow 2
6 will flow in the tower while avoiding the vicinity of the spray nozzle 4 and flowing unevenly. On the other hand, in the present invention shown in FIG. 3, since the interval between the spray nozzles 4 is narrower than that in the conventional method, the interference between the liquid droplets is very large and the liquid droplet diameter is inevitably small. Further, as shown in FIG. 3, since the density of the sprayed droplets becomes substantially uniform, the gas flow 26 does not cause a drift as in the conventional method. Spray nozzle 4
If the space between the two is narrowed, the liquid droplets become small to some extent, which is advantageous in terms of performance and gas flow, and the tower height can be reduced accordingly.
【００１７】図５には、スプレーノズル４の間隔を０．
５ｍとしたスプレーノズル４から噴霧される平均液滴径
を変化させて脱硫率との関係を調べた結果を示す。噴霧
液滴径が３mmの場合を基準として脱硫率を比較すると、
噴霧液滴径を２．５mm以下にすると脱硫率は大幅に低下
し始め１mmの液滴径では約６０％にまで低下する。これ
は噴霧液滴径が小さくなると液滴同士の衝突により液滴
径が１mm以下になり、ガスにより同伴されるミスト飛散
量が増加するためと考えられる。このように、スプレー
ノズル４の間隔を狭くして液滴同士を衝突させる場合に
は、噴霧液滴径を２．５mmよりも大きく、例えば２．７
mm以上に大きくすることが非常に重要となる。In FIG. 5, the distance between the spray nozzles 4 is 0.
The results of investigating the relationship with the desulfurization rate by changing the average droplet diameter sprayed from the spray nozzle 4 having a length of 5 m are shown. Comparing the desulfurization rates based on the case where the spray droplet diameter is 3 mm,
When the diameter of the sprayed droplet is 2.5 mm or less, the desulfurization rate starts to significantly decrease, and with a droplet diameter of 1 mm, it decreases to about 60%. It is considered that this is because when the atomized droplet diameter becomes smaller, the droplet diameter becomes 1 mm or less due to collision of the droplets, and the amount of mist scattered by the gas increases. In this way, when the spray nozzles 4 are narrowed and the droplets are made to collide with each other, the diameter of the sprayed droplet is larger than 2.5 mm, for example, 2.7.
It is very important to make it larger than mm.
【００１８】図６には、実機で用いられているホロコー
ンノズルを用いて、平均液滴径：３mmの液滴を噴霧した
場合のスプレーノズル４の間隔と液滴径の関係をＰＤＰ
Ａ装置を用いて測定した結果を示す。スプレーノズル４
の間隔が１．５ｍの条件での液滴径を１とすると、スプ
レーノズル４の間隔を狭くするほど液滴径は小さくなる
ことがわかる。すなわちスプレーノズル４の間隔を狭く
すると、噴霧された液滴径の衝突回数が増加するので液
滴径はある程度小さくなる。スプレーノズル４の間隔が
０．５ｍでは０．７４まで液滴径比は小さくなり、この
場合図６に示した実験範囲の実際の液滴径は１．４〜
２．２mmとなりガスに同伴されて飛散する液滴径にまで
は小さくならない。FIG. 6 shows the relationship between the distance between the spray nozzles 4 and the droplet diameter when a droplet having an average droplet diameter of 3 mm is sprayed using a hollow cone nozzle used in an actual machine.
The result measured using the A apparatus is shown. Spray nozzle 4
It can be seen that, assuming that the droplet diameter is 1 when the distance is 1.5 m, the droplet diameter becomes smaller as the distance between the spray nozzles 4 becomes narrower. That is, when the distance between the spray nozzles 4 is narrowed, the number of collisions of the sprayed droplet diameter increases, so that the droplet diameter becomes small to some extent. When the distance between the spray nozzles 4 is 0.5 m, the droplet diameter ratio becomes as small as 0.74. In this case, the actual droplet diameter in the experimental range shown in FIG.
It becomes 2.2 mm, and it does not become smaller to the diameter of the droplets entrained by the gas and scattered.
【００１９】図７には、図６で同時に測定したスプレー
ノズル４の間隔と液滴比表面積との関係を示す。同様に
スプレーノズル４の間隔が１．５ｍの比表面積を１とす
れば、スプレーノズル４の間隔を狭くすると液滴の比表
面積は増加し、スプレーノズル４の間隔を０．４ｍ程度
にすると液滴の比表面積は約３倍に増加することがわか
る。したがって、このようにスプレーノズル４の間隔を
狭くするとＳＯ2 ガスとの反応面積が増加するので、脱
硫性能も増加することが期待できる。FIG. 7 shows the relationship between the distance between the spray nozzles 4 and the specific surface area of the liquid droplets, which were simultaneously measured in FIG. Similarly, if the specific surface area when the interval between the spray nozzles 4 is 1.5 m is 1, the specific surface area of the droplets increases when the interval between the spray nozzles 4 is narrowed, and when the interval between the spray nozzles 4 is approximately 0.4 m It can be seen that the specific surface area of the drops increases by about 3 times. Therefore, when the distance between the spray nozzles 4 is narrowed in this way, the reaction area with the SO 2 gas increases, and it can be expected that the desulfurization performance also increases.
【００２０】図８には、本発明の実施例を実機の１／５
規模の寸法のパイロット試験で実施した結果を示す。ガ
ス流速は５ｍ／ｓから１０ｍ／ｓの条件について、液ガ
ス比：１５、ＳＯ2 濃度：７００ppm の条件でスプレー
ノズル４の間隔を変化して脱硫率との関係を調べた結果
であるが、スプレーノズル４の間隔を１．５ｍから小さ
くすると脱硫率は増加している。スプレーノズル４の間
隔は０．５ｍ前後で最大となり、これよりスプレーノズ
ル４の間隔を狭くすると液滴径が小さくなりすぎるので
ガスに同伴された飛散する液滴の割合が増加するため、
逆に脱硫率は低下している。この結果より、スプレーノ
ズル４の間隔を０．２５ｍから１．１ｍの範囲に配置す
ることが重要であることがわかる。FIG. 8 shows a fifth embodiment of the present invention, which is ⅕ of the actual machine.
The results of a pilot test of scale dimensions are shown. When the gas flow velocity is from 5 m / s to 10 m / s, the relationship between the desulfurization rate was examined by changing the interval of the spray nozzle 4 under the conditions of liquid gas ratio: 15 and SO 2 concentration: 700 ppm. When the distance between the spray nozzles 4 is reduced from 1.5 m, the desulfurization rate increases. The distance between the spray nozzles 4 becomes maximum at around 0.5 m, and if the distance between the spray nozzles 4 is made narrower than this, the droplet diameter becomes too small and the proportion of scattered droplets entrained in the gas increases.
On the contrary, the desulfurization rate is decreasing. From this result, it can be seen that it is important to arrange the spray nozzles 4 in the range of 0.25 m to 1.1 m.
【００２１】本発明を用いると、脱硫塔でのスプレーノ
ズル４の間隔を狭くでき噴霧液滴の衝突により液滴径が
ある程度小さくなる。これにより脱硫性能が向上するの
でスプレ配管１５の段数が減り、脱硫塔高が下がり循環
液のポンプ動力も低減ができ、脱硫性能および脱塵性能
も同時に改善できる。According to the present invention, the space between the spray nozzles 4 in the desulfurization tower can be narrowed and the droplet diameter can be reduced to some extent by the collision of the spray droplets. As a result, the desulfurization performance is improved, the number of stages of the spray pipe 15 is reduced, the desulfurization tower height is lowered, the pump power of the circulating liquid can be reduced, and the desulfurization performance and the dust removal performance can be improved at the same time.
【００２２】[0022]
【発明の効果】本発明によれば、脱硫塔でのノズル間隔
を所定範囲内で狭くするとノズル段数が減るので、脱硫
塔高が下がり循環液のポンプ動力も低減ができる。さら
に、塔内でのガス偏流の防止が可能となり脱硫性能およ
び脱塵性能も同時に向上できる。According to the present invention, when the nozzle spacing in the desulfurization tower is narrowed within a predetermined range, the number of nozzle stages is reduced, so that the desulfurization tower height is lowered and the pump power of the circulating liquid can be reduced. Furthermore, it is possible to prevent gas drift in the tower, and simultaneously improve desulfurization performance and dust removal performance.
【図１】本発明の実施例にかかる脱硫装置構造図。FIG. 1 is a structural diagram of a desulfurization device according to an embodiment of the present invention.
【図２】本発明の実施例にかかる脱硫装置構造図。FIG. 2 is a structural diagram of a desulfurization device according to an embodiment of the present invention.
【図３】本発明における噴霧液滴とガスの流れを示す
図。FIG. 3 is a diagram showing the flow of spray droplets and gas in the present invention.
【図４】従来技術における噴霧液滴とガスの流れを示す
図。FIG. 4 is a diagram showing a flow of atomized droplets and a gas in a conventional technique.
【図５】噴霧液滴径と脱硫率の関係を示す図。FIG. 5 is a diagram showing a relationship between a sprayed droplet diameter and a desulfurization rate.
【図６】ノズル間隔と液滴径の関係を示す図。FIG. 6 is a diagram showing a relationship between a nozzle interval and a droplet diameter.
【図７】ノズル間隔と液滴比表面積の関係を示す図。FIG. 7 is a diagram showing a relationship between a nozzle interval and a droplet specific surface area.
【図８】ノズル間隔と脱硫性能の関係を示す図。FIG. 8 is a diagram showing the relationship between nozzle spacing and desulfurization performance.
【図９】従来の技術を示す図。FIG. 9 is a diagram showing a conventional technique.
１…脱硫塔本体、２…入口ダクト、３…出口ダクト、４
…スプレーノズル、５…循環ポンプ、６…循環タンク、
７…攪拌機、８…空気吹込み管、９…デミスタ、１０…
吸収液抜出し管、１１…循環液配管、１２…石膏処理装
置、１３…石灰石供給管、１５…スプレ配管。1 ... Desulfurization tower main body, 2 ... Entrance duct, 3 ... Exit duct, 4
... spray nozzle, 5 ... circulation pump, 6 ... circulation tank,
7 ... Stirrer, 8 ... Air blowing tube, 9 ... Demister, 10 ...
Absorption liquid extraction pipe, 11 ... Circulating liquid pipe, 12 ... Gypsum processing device, 13 ... Limestone supply pipe, 15 ... Spray pipe.
───────────────────────────────────────────────────── フロントページの続き (72)発明者 吉川 博文 広島県呉市宝町３番36号 バブコック日 立株式会社 呉研究所内 (72)発明者 野沢 滋 広島県呉市宝町６番９号 バブコック日 立株式会社 呉工場内 (56)参考文献 特開 昭56−21628（ＪＰ，Ａ) (58)調査した分野(Int.Cl.7，ＤＢ名) B01D 53/34 - 53/80 B01D 53/18 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hirofumi Yoshikawa, No. 36 Takara-cho, Kure-shi, Hiroshima Prefecture Babcock Hiritsu Co., Ltd., Kure Research Institute Co., Ltd. (72) Shigeru Nozawa, No. 6-9, Takara-cho, Kure-shi, Hiroshima Prefecture Kure Factory Co., Ltd. (56) References JP-A-56-21628 (JP, A) (58) Fields investigated (Int.Cl. 7 , DB name) B01D 53/34-53/80 B01D 53/18
Claims (3)
し、これにカルシウム系吸収液をスプレーノズルにより
噴霧して排ガス中の硫黄酸化物を吸収し、吸収した吸収
液を吸収液循環タンク内に収容し、循環タンク内の吸収
液中に空気を吹込んで液中の亜硫酸塩を酸化して石膏を
生成させるとともに、循環タンク内の吸収液を前記スプ
レーノズルに供給する湿式排ガス脱硫方法において、前
記スプレーノズルから噴霧される平均噴霧吸収液滴径を
２．７mm以上とし、かつ各ノズルの噴射口間隔を０．２
５ｍ〜１．１ｍの範囲として噴霧液滴どうしを衝突干渉
させることを特徴とする湿式排ガス脱硫方法。1. A sulfur oxide-containing exhaust gas is introduced into a desulfurization tower, and a calcium-based absorbing solution is sprayed onto the desulfurization tower by a spray nozzle to absorb the sulfur oxide in the exhaust gas, and the absorbed absorbing solution is absorbed into a liquid circulation tank. In a wet exhaust gas desulfurization method of accommodating in the inside, blowing air into the absorption liquid in the circulation tank to oxidize sulfite in the liquid to generate gypsum, and supplying the absorption liquid in the circulation tank to the spray nozzle. , Before
Average spray absorption droplet size sprayed from the spray nozzle
2.7 mm or more, and the nozzle spacing between nozzles is 0.2
A wet exhaust gas desulfurization method characterized in that spray droplets collide and interfere with each other in a range of 5 m to 1.1 m.
滴径が主として１．４mmないし２．２mmのもので構成さ
れることを特徴とする湿式排ガス脱硫方法。2. The wet exhaust gas desulfurization method according to claim 1, wherein the spray droplet diameter after collision interference is mainly 1.4 mm to 2.2 mm.
入口と処理された排ガスを排出する排ガス出口とを有す
る脱硫塔と、脱硫塔内に排ガス流れ方向に多段に配置さ
れて脱硫塔内に導入された排ガスにカルシウム系吸収液
を噴霧するスプレーノズルと、脱硫塔内で噴霧され排ガ
ス中の硫黄酸化物を吸収した吸収液を収容する吸収液循
環タンクと、循環タンク内の吸収液をスプレーノズルに
循環供給する循環装置と、循環タンク内に酸化用空気を
吹込む装置とを備えた湿式排ガス脱硫装置において、前
記スプレーノズルの平均噴霧液滴径が２．７mm以上、ス
プレーノズル口配置間隔が０．２５ｍないし１．１ｍと
なるようにスプレーノズル部を構成したことを特徴とす
る湿式排ガス脱硫装置。3. A desulfurization tower having an exhaust gas inlet for introducing the sulfur oxide-containing exhaust gas and an exhaust gas outlet for discharging the treated exhaust gas, and a desulfurization tower which is arranged in multiple stages in the exhaust gas flow direction and is introduced into the desulfurization tower. Nozzle for spraying a calcium-based absorption liquid to the generated exhaust gas, an absorption liquid circulation tank for containing the absorption liquid that has absorbed the sulfur oxides in the exhaust gas sprayed in the desulfurization tower, and a spray nozzle for the absorption liquid in the circulation tank in the wet flue gas desulfurization apparatus having a circulation supplying circulation device, and a blown apparatus oxidizing air to circulate inside the tank, before
The wet exhaust gas desulfurization apparatus, wherein the spray nozzle section is configured such that the average spray droplet diameter of the spray nozzle is 2.7 mm or more and the spray nozzle port arrangement interval is 0.25 m to 1.1 m.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15621394A JP3380046B2 (en) | 1994-07-07 | 1994-07-07 | Wet exhaust gas desulfurization method and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP15621394A JP3380046B2 (en) | 1994-07-07 | 1994-07-07 | Wet exhaust gas desulfurization method and apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0819726A JPH0819726A (en) | 1996-01-23 |
| JP3380046B2 true JP3380046B2 (en) | 2003-02-24 |
Family
ID=15622839
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP15621394A Expired - Fee Related JP3380046B2 (en) | 1994-07-07 | 1994-07-07 | Wet exhaust gas desulfurization method and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3380046B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5840263A (en) * | 1996-05-30 | 1998-11-24 | Mitsubishi Heavy Industries, Ltd. | Flue gas treating process and system |
| JP5289668B2 (en) * | 2005-05-18 | 2013-09-11 | バブコック日立株式会社 | Wet flue gas desulfurization equipment |
| CN102716661A (en) * | 2012-07-10 | 2012-10-10 | 中电投远达环保工程有限公司 | Conveyor dry powder direct-feeding desulphurization system |
| CN102716639B (en) * | 2012-07-20 | 2014-08-20 | 中电投远达环保工程有限公司 | High-efficiency wet-type electric dust removal and desulfuration system and process |
| CN112547387B (en) * | 2020-12-03 | 2021-11-16 | 武汉天空蓝环保科技有限公司 | Spray gun with automatic cleaning function and desulfurization waste water zero discharge system |
-
1994
- 1994-07-07 JP JP15621394A patent/JP3380046B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0819726A (en) | 1996-01-23 |
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