JP2738750B2 - Control method of exhaust gas desulfurization equipment - Google Patents
Control method of exhaust gas desulfurization equipmentInfo
- Publication number
- JP2738750B2 JP2738750B2 JP1209893A JP20989389A JP2738750B2 JP 2738750 B2 JP2738750 B2 JP 2738750B2 JP 1209893 A JP1209893 A JP 1209893A JP 20989389 A JP20989389 A JP 20989389A JP 2738750 B2 JP2738750 B2 JP 2738750B2
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- Japan
- Prior art keywords
- amount
- sulfite
- concentration
- ion concentration
- washing
- Prior art date
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Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、ボイラー排ガス，焼結炉排ガス，都市ゴミ
焼却炉排ガス，金属加熱炉排ガス等の硫黄酸化物（S
OX）を含む排ガスの脱硫設備の制御方法に関する。DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to sulfur oxide (S) such as boiler exhaust gas, sintering furnace exhaust gas, municipal waste incinerator exhaust gas, metal heating furnace exhaust gas, etc.
O X) a method of controlling the desulfurization of exhaust gas containing.
従来、この種の排ガス脱硫設備の制御方法としては、
基本的には第４図に示す方式によって行われる。Conventionally, as a control method for this type of exhaust gas desulfurization equipment,
Basically, it is performed by the method shown in FIG.
同図を参照して、排ガス発生源からの排ガスは、排ガ
ス入口ダクト71から洗浄塔72に導入され、循環ポンプ73
および配管74によって循環する洗浄液によって冷却，除
塵されると同時に、排ガス中の亜硫酸ガスは次のような
反応により洗浄液に吸収される。Referring to the figure, exhaust gas from an exhaust gas generation source is introduced into a washing tower 72 from an exhaust gas inlet duct 71, and is supplied to a circulation pump 73.
At the same time as cooling and dust removal by the cleaning liquid circulating through the pipe 74, the sulfurous acid gas in the exhaust gas is absorbed by the cleaning liquid by the following reaction.
SO2＋H2O→H+＋HSO3 - （１） MgSO3＋H+＋HSO3 -→Mg2+＋2HSO3 - （２） H+＋HSO3 -＋1/2O2→2H+＋SO4 （３） 2H+＋SO4 2-＋Mg（OH）２→MgSO4＋2H2O （４） Mg2+＋2HSO3 -＋Mg（OH）２→2MgSO3＋2H2O （５） MgSO3＋1/2O2→MgSO4 （６） CaSO3＋1/2O2→CaSO4 （７） すなわち、（１）式で吸収された亜硫酸ガスは（２）
式で示されるように亜硫酸マグネシウムと反応し、亜硫
酸イオンを生成すると共に、一部（３）式で示されるよ
うに排ガス中の酸素ガスと反応し自然酸化することで硫
酸イオンを生成する。 SO 2 + H 2 O → H + + HSO 3 - (1) MgSO 3 + H + + HSO 3 - → Mg 2+ + 2HSO 3 - (2) H + + HSO 3 - + 1 / 2O 2 → 2H + + SO 4 (3) 2H + + SO 4 2+ Mg (OH) 2 → MgSO 4 + 2H 2 O (4) Mg 2+ + 2HSO 3 - + Mg (OH) 2 → 2MgSO 3 + 2H 2 O (5) MgSO 3 + 1 / 2O 2 → MgSO 4 (6) CaSO 3 + 1 / 2O 2 → CaSO 4 (7) That is, the sulfurous acid gas absorbed by the equation (1) is (2)
As shown by the formula, it reacts with magnesium sulfite to generate sulfite ions, and also partially reacts with the oxygen gas in the exhaust gas and spontaneously oxidizes to generate sulfate ions as shown by formula (3).
またH+やHSO3 -は吸収剤であるMg（OH）２との中和に
より（４）式，（５）式で示されるように、硫酸マグネ
シウムや亜硫酸マグネシウムを生成する。H + and HSO 3 − generate magnesium sulfate and magnesium sulfite as shown by the formulas (4) and (5) by neutralization with Mg (OH) 2 as an absorbent.
（６）式は、（５）式で生成した溶解度の小さい亜硫
酸マグネシウムを溶解度の大きい硫酸マグネシウムに変
換させる反応である。洗浄塔に酸化用空気を吹込むこと
により、亜硫酸マグネシウムを強制酸化させることで亜
硫酸マグネシウムの析出によるスケーリングを防止する
と同時に、洗浄塔からの洗浄液の抜出し量の低減を図っ
ている。Equation (6) is a reaction for converting the magnesium sulphite with low solubility generated in equation (5) to magnesium sulphate with high solubility. By blowing oxidizing air into the washing tower, magnesium sulfite is forcibly oxidized to prevent scaling due to precipitation of magnesium sulfite, and at the same time, to reduce the amount of the washing liquid extracted from the washing tower.
加えて、水酸化マグネシウム等の市販のマグネシウム
化合物には不純物として１〜２％程度のカルシウム化合
物を含んでいるため、脱硫反応により亜硫酸カルシウム
が生成している。In addition, since a commercially available magnesium compound such as magnesium hydroxide contains about 1 to 2% of a calcium compound as an impurity, calcium sulfite is generated by a desulfurization reaction.
この際、亜硫酸カルシウムは、亜硫酸マグネシウムと
比較して水に対する溶解度は遥かに小さいので、亜硫酸
カルシウムの析出によるスケーリングを防止することが
重要な問題である。At this time, since calcium sulfite has much lower solubility in water than magnesium sulfite, it is an important problem to prevent scaling due to precipitation of calcium sulfite.
従って、（６）式と同様に、（７）式によって亜硫酸
カルシウムを強制酸化させる必要があるが、（２）式で
示されるように、亜硫酸塩は直接の吸収剤となるため、
亜硫酸塩を過剰に酸化した場合、吸収に必要な亜硫酸塩
がなくなる問題があった。Therefore, similarly to the formula (6), it is necessary to forcibly oxidize the calcium sulfite according to the formula (7). However, as shown in the formula (2), the sulfite becomes a direct absorbent.
When the sulfite is excessively oxidized, there is a problem that the sulfite necessary for absorption is lost.
そこで従来は、カルシウムイオンの蓄積を抑えスケー
リングを防止できる程度以上に析出し機構75から洗浄液
を抜出しておいて、そのうえで吸収に必要な亜硫酸イオ
ン濃度を確保するように配管76から洗浄塔に酸化用空気
を吹込んでいた。Therefore, conventionally, the amount of calcium ions is reduced to a level that can suppress scaling and prevent scaling, the cleaning solution is extracted from the mechanism 75, and then oxidized from the pipe 76 to the cleaning tower to secure the sulfite ion concentration required for absorption. I was blowing air.
具体的には、亜硫酸カルシウム塩の生成量や亜硫酸イ
オンの生成量にかえて、それらに相関のある洗浄塔入口
の総亜硫酸ガスの流量を、排ガス流量の信号３と洗浄塔
入口の亜硫酸ガス濃度の信号31の積として掛算器77で生
成して、これを洗浄塔入口の総亜硫酸ガスの流量を示す
信号として関数発生器78,79に入力し、出力としてそれ
ぞれ洗浄液の抜出し量17を制御量とする調節器66の設定
値、酸化用の吹込み空気量44を制御量とする調節器69の
設定値を得る。Specifically, instead of the amount of calcium sulfite produced and the amount of sulfite ion produced, the flow rate of the total sulfur dioxide at the inlet of the washing tower, which is correlated with them, is determined by the signal 3 of the exhaust gas flow rate and the sulfur dioxide gas concentration at the inlet of the washing tower. Is generated by the multiplier 77 as a product of the signals 31 and is input to the function generators 78 and 79 as a signal indicating the flow rate of the total sulfurous acid gas at the inlet of the cleaning tower, and the output 17 of the cleaning liquid is controlled as the output as the control amount. , And the set value of the adjuster 69 with the oxidizing blowing air amount 44 as the control amount.
関数発生器78に採用された関数は、洗浄液の抜出し量
17を洗浄塔入口の総亜硫酸ガス流量の関数とし、亜硫酸
カルシウムの析出しない程度の洗浄液濃度（全硫酸濃度
として約４〜７％）となる量に設定される。The function used in the function generator 78 is the amount of cleaning liquid withdrawn.
17 is a function of the total flow rate of sulfurous acid gas at the inlet of the washing tower, and is set to an amount that gives a washing solution concentration (about 4 to 7% as a total sulfuric acid concentration) at which calcium sulfite does not precipitate.
関数発生器79に採用された関数は、酸化用の吹込み空
気量44を洗浄塔入口の総亜硫酸ガス流量の関数とし、吸
収のために必要な洗浄液中の亜硫酸イオン濃度となるよ
うに設定されている。The function adopted in the function generator 79 is set so that the blowing air amount 44 for oxidation is a function of the total sulfurous acid gas flow rate at the inlet of the washing tower, and the concentration of sulfite ions in the washing solution required for absorption is set. ing.
上記従来の排ガス脱硫設備の制御方法では、洗浄塔か
らの洗浄液の抜出し量や洗浄塔への酸化用の吹込み空気
量を洗浄塔入口の総亜硫酸ガス流量の関数として調節す
るものであるため、洗浄液の抜出し量が多く、また、吹
込み空気量を適切に調節できないという欠点があった。In the control method of the above-mentioned conventional exhaust gas desulfurization equipment, since the amount of the cleaning liquid withdrawn from the cleaning tower and the blowing air amount for oxidation to the cleaning tower are adjusted as a function of the total sulfur dioxide gas flow rate at the cleaning tower inlet, There are drawbacks in that the amount of cleaning liquid withdrawn is large and the amount of blown air cannot be appropriately adjusted.
本発明において解決すべき課題は、上記従来の排ガス
脱硫方式の欠点を解消して亜硫酸カルシウム塩によるス
ケーリングをしない範囲で洗浄液の亜硫酸イオンによる
吸収能を確保しながらも、抜出し量の低減と吹込み空気
量の低減をすることにある。The problem to be solved in the present invention is to solve the drawbacks of the conventional exhaust gas desulfurization method described above and reduce the amount of withdrawal and blowing while ensuring the absorption capacity of the cleaning solution by sulfite ions within a range not to be scaled by calcium sulfite. The purpose is to reduce the amount of air.
本発明は、オン・ライン計測可能な状態量から関数発
生器を用いて洗浄液中のカルシウムイオン濃度と亜硫酸
イオン濃度および吸収のために必要な洗浄液中の亜硫酸
イオンの濃度を算出し、前記算出された洗浄液中のカル
シュウムイオン濃度と洗浄液中の亜硫酸イオン濃度との
積と予め設定される最適なカルシュウムイオン濃度と亜
硫酸イオン濃度との積により洗浄塔からの洗浄液の抜き
出し量を操作量とするカスケード制御と、前記算出され
た洗浄液中の亜硫酸イオン濃度と吸収に必要な洗浄液中
の亜硫酸イオン濃度とにより洗浄塔への吹き込み空気量
を操作量とするカスケード制御との二つのカスケード制
御をすることにより上記課題を解決した。The present invention uses a function generator to calculate the calcium ion concentration and the sulfite ion concentration in the cleaning liquid and the concentration of sulfite ions in the cleaning liquid necessary for absorption from the state quantity that can be measured on-line, and the calculated value is calculated. Cascade control using the product of the concentration of calcium ions in the washed washing solution and the concentration of sulfite ions in the washing solution and the product of the preset optimal calcium ion concentration and the concentration of sulfite ion as the manipulated variable to extract the amount of washing solution from the washing tower By performing two cascade controls of the calculated sulfite ion concentration in the washing solution and the sulfite ion concentration in the washing solution necessary for absorption, and a cascade control in which the amount of air blown into the washing tower is an operation amount. Solved the problem.
排ガス量，洗浄塔入口の亜硫酸ガス濃度，洗浄塔出口
の亜硫酸ガス濃度，洗浄塔入口のダスト濃度，洗浄塔出
口のダスト濃度，吸収剤投入量等の信号と制御量である
吹込み空気量と洗浄液の抜出し量の信号を計測し、予め
設定された関数発生器に入力することにより、その出力
として洗浄液中での亜硫酸イオンの生成量とその濃度及
び洗浄液中へのカルシウムイオン流入量とその濃度の信
号を得る。Signals such as the amount of exhaust gas, the concentration of sulfurous acid gas at the inlet of the washing tower, the concentration of sulfurous acid gas at the outlet of the washing tower, the concentration of dust at the inlet of the washing tower, the concentration of dust at the outlet of the washing tower, and the amount of absorbent admitted. By measuring the signal of the amount of withdrawal of the cleaning liquid and inputting it to a preset function generator, the output and concentration of sulfite ions in the cleaning liquid and the inflow and concentration of calcium ions in the cleaning liquid are output. Signal.
加えて、洗浄液の吸収能力と強い相関がある洗浄液中
での亜硫酸イオンの濃度を、洗浄塔入口の亜硫酸ガス濃
度をはじめとするオン・ライン計測可能な状態量の関数
として、関数発生器を予め設定することにより、上記同
様にその出力として吸収のために必要な洗浄液中の亜硫
酸イオンの濃度の信号を得る。In addition, a function generator is used to determine the concentration of sulfite ions in the cleaning liquid, which has a strong correlation with the absorption capacity of the cleaning liquid, as a function of the on-line measurable state quantity, including the concentration of sulfurous acid gas at the inlet of the cleaning tower. By setting, the signal of the concentration of the sulfite ion in the cleaning liquid necessary for the absorption is obtained as the output as described above.
このようにして得られた吸収のために必要な洗浄液中
の亜硫酸イオンの濃度の信号を設定値とし、洗浄液中の
亜硫酸イオン濃度を制御量とする一次調節器でもって、
吹込み空気量を検出しこの吹込み空気量を制御量とする
二次調節器の設定値を補正する。この二次調節器の出力
信号によって洗浄塔に酸化用空気を吹込む配管に設けら
れた調節弁を操作するというカスケード制御をする。With a primary controller that sets the signal of the concentration of sulfite ions in the cleaning solution necessary for absorption obtained in this way as a set value and controls the sulfite ion concentration in the cleaning solution as a control amount,
The blown air amount is detected, and the set value of the secondary regulator using the blown air amount as a control amount is corrected. A cascade control of operating a control valve provided in a pipe for blowing oxidizing air into the washing tower is performed by an output signal of the secondary controller.
更に、スケーリングせず、且つ洗浄塔から洗浄液の抜
出し量が最小となる洗浄液中の亜硫酸イオン濃度とカル
シウムイオン濃度の積の最適値を予め亜硫酸イオンとカ
ルシウムイオンの溶解度積を基準として求めておき、こ
の数値を設定値とし上記で得られた洗浄液中の亜硫酸イ
オン濃度と洗浄液中のカルシウムイオン濃度の積を制御
量とする一次調節器の出力でもって、洗浄液の抜出し量
を検出しこの洗浄液の抜出し量を制御量とする二次調節
器の設定値を補正する。この二次調節器の出力信号によ
って洗浄塔から洗浄液を抜出す配管に設けられた調節弁
を操作するというカスケード制御をする。Further, without scaling, the optimum value of the product of the sulfite ion concentration and the calcium ion concentration in the washing solution in which the amount of the washing solution withdrawn from the washing tower is minimized in advance based on the solubility product of the sulfite ion and the calcium ion, With this numerical value as a set value, the output of the primary controller, which controls the product of the sulfite ion concentration in the washing solution obtained above and the calcium ion concentration in the washing solution as a control amount, detects the amount of washing solution withdrawn, and withdraws this washing solution. Correct the set value of the secondary regulator using the amount as the control amount. The output signal of the secondary controller performs a cascade control of operating a control valve provided on a pipe for extracting the cleaning liquid from the cleaning tower.
このように、吸収のために必要な洗浄液中の亜硫酸イ
オンの濃度を一次調節器の設定値とし、吹込み空気量を
二次調節器の操作量とするカスケード制御をすれば、洗
浄塔入口亜硫酸ガス濃度の変動があっても吸収のために
必要な亜硫酸イオンの濃度をトレースし、かつ洗浄液の
抜出し量や吹込み空気量が低減できる。In this way, if cascade control is performed in which the concentration of sulfite ions in the washing solution necessary for absorption is set to the primary controller and the amount of air blown is the operation amount of the secondary controller, the sulfite ion at the inlet of the washing tower can be obtained. Even if the gas concentration fluctuates, the concentration of the sulfite ion required for absorption can be traced, and the amount of cleaning solution withdrawn and the amount of blown air can be reduced.
また、スケーリングせず、かつ洗浄液の抜出し量が最
小となるように設定した亜硫酸イオン濃度とカルシウム
イオン濃度の積を一次調節器の設定値とし、洗浄液の抜
出し量を二次調節器の操作量とするカスケード制御をす
れば、排ガスのSO2負荷に代表される酸負荷の変動やダ
スト負荷の変動があっても、スケールトラブルを生ずる
ことなく、洗浄液の抜出し量を低減できる。Also, the product of the sulfite ion concentration and the calcium ion concentration, which was set without scaling and the amount of the cleaning liquid withdrawn was minimized, was set as the set value of the primary controller, and the amount of the cleaning liquid withdrawn was the operating amount of the secondary controller. With such a cascade control, even if there is a change in the acid load represented by the SO 2 load of the exhaust gas or a change in the dust load, it is possible to reduce the discharge amount of the cleaning liquid without causing a scale trouble.
以下に本発明の実施例を第１図，第２図，第３図を参
照して説明する。An embodiment of the present invention will be described below with reference to FIG. 1, FIG. 2, and FIG.
まず、カルシウムイオン濃度の算出にあたっては、第
１図に示すように、オン・ラインで測定される洗浄塔入
口のダスト濃度1,洗浄塔出口のダスト濃度2,排ガス流量
３の各信号とこれらの信号を減算する減算器4,掛算する
掛算器５を用いて洗浄塔へのダスト負荷６を計算する。
これに予め測定されたダスト中のカルシウム含有濃度７
とダスト中のカルシウム反応率８の両信号を掛算器９で
掛算した数値を再び掛算器10で掛算し、洗浄塔に流入す
るダスト起因のカルシウムイオンの量11を算出する。First, in calculating the calcium ion concentration, as shown in FIG. 1, the signals of the dust concentration at the inlet of the washing tower, the dust concentration at the outlet of the washing tower 2, and the exhaust gas flow rate 3, which are measured on-line, are shown. A dust load 6 to the washing tower is calculated using a subtractor 4 for subtracting a signal and a multiplier 5 for multiplication.
The concentration of calcium contained in the dust previously measured was 7
The multiplier 10 multiplies the signal obtained by multiplying the two signals, that is, the calcium reaction rate 8 in the dust, by the multiplier 9 again to calculate the amount 11 of the calcium ions caused by dust flowing into the washing tower.
また、オン・ラインで測定される洗浄塔への脱硫剤投
入量12と、予め測定された脱硫剤中のカルシウム成分の
含有濃度13を掛算器14で掛算することにより、洗浄塔に
流入する脱硫剤起因のカルシウムイオンの量15を算出す
る。In addition, the amount of desulfurizing agent input 12 to the washing tower measured on-line and the concentration 13 of the calcium component contained in the desulfurizing agent measured in advance are multiplied by a multiplier 14 to obtain the desulfurization flowing into the washing tower. The amount 15 of calcium ions caused by the agent is calculated.
更に、後述する手順で算出した洗浄液中に溶解してい
るカルシウムイオン濃度22と洗浄液の抜出し量17を掛算
器18で掛算することにより、洗浄塔から流出するカルシ
ウムイオンの量19を算出する。Further, the amount 19 of calcium ions flowing out of the washing tower is calculated by multiplying the concentration 22 of calcium ions dissolved in the washing solution calculated in the procedure described later by the amount 17 of the extracted washing solution by the multiplier 18.
このように、ダストや脱硫剤に起因して流入し溶解す
るカルシウムイオンの量と、抜出し洗浄液に伴って流出
するカルシウムイオンの量から、カルシウムイオンのバ
ランスを加算器16,減算器20で計算し、これにより洗浄
液中のカルシウムイオン濃度を計算する関数発生器21の
出力として、洗浄液中のカルシウムイオン濃度22を得
る。In this way, the balance of calcium ions is calculated by the adder 16 and the subtractor 20 from the amount of calcium ions flowing in and dissolving due to dust and desulfurizing agent and the amount of calcium ions flowing out with the withdrawal cleaning liquid. Thereby, the calcium ion concentration 22 in the cleaning liquid is obtained as an output of the function generator 21 for calculating the calcium ion concentration in the cleaning liquid.
次に亜硫酸イオン濃度の算出に当たっては、第２図に
示すように、オン・ラインで測定される洗浄塔入口の亜
硫酸ガス濃度31,洗浄塔出口の亜硫酸ガス濃度32,排ガス
流量３の各信号とこれらの信号を減算する減算器34,掛
算する掛算器35を用いて洗浄塔へのSO2負荷41を計算す
る。これにオン・ラインで測定される排ガス中の酸素濃
度36と洗浄塔入口の亜硫酸ガス濃度31をパラメータとす
る関数発生器38を用いて、洗浄塔での亜硫酸イオンの自
然酸化率39を計算する。Next, in calculating the sulfite ion concentration, as shown in FIG. 2, the signals of the sulfite gas concentration 31 at the inlet of the washing tower, the sulfur dioxide gas concentration 32 at the outlet of the washing tower, and the exhaust gas flow rate 3 were measured on-line. subtractor 34 for subtracting the signals, calculates the SO 2 load 41 to washing column with multiplier 35 for multiplying. Calculate the natural oxidation rate 39 of sulfite ions in the washing tower using the function generator 38 with the parameters of the oxygen concentration 36 in the exhaust gas measured on-line and the sulfur dioxide concentration 31 at the inlet of the washing tower. .
この自然酸化率39を数値１から減じた値を演算器40で
求め、洗浄塔へのSO2負荷41と掛算器42で掛算すること
により、洗浄塔に流入する亜硫酸イオンの量43が算出で
きる。A value obtained by subtracting the natural oxidation rate 39 from the numerical value 1 is obtained by the arithmetic unit 40 and multiplied by the SO 2 load 41 to the washing tower and the multiplier 42, whereby the amount 43 of sulfite ions flowing into the washing tower can be calculated. .
また、オン・ラインで測定される空気吹込み量44,洗
浄液pH45と予めオン・ラインで測定された洗浄液中の塩
素イオン濃度46をパラメータとする関数発生器47を用い
て洗浄塔での強制酸化量48を計算する。さらに、後述す
る手順で算出した洗浄塔での亜硫酸イオン濃度55とオン
・ラインで測定される洗浄液の抜出し量17を掛算器51で
掛算することにより、洗浄塔より流出する亜硫酸イオン
の量52を算出する。In addition, forced oxidation in the cleaning tower is performed using a function generator 47 having parameters of an air blowing amount 44 measured on-line, a cleaning solution pH 45, and a chlorine ion concentration 46 in the cleaning solution previously measured on-line. Calculate the quantity 48. Further, by multiplying the sulfite ion concentration 55 in the washing tower calculated in the procedure described below and the amount 17 of the washing solution extracted online measured by the multiplier 51 with the multiplier 51, the amount 52 of the sulfite ion flowing out of the washing tower is calculated. calculate.
このように、洗浄塔へのSO2負荷41と自然酸化率39か
ら推算できた亜硫酸イオンの流入量43と推算できた亜硫
酸イオンの酸化量48及び流出する亜硫酸イオンの量52と
で亜硫酸イオンのバランスを減算器49,53で計算し、こ
れにより洗浄液中の亜硫酸イオン濃度を計算する関数発
生器54の出力として、亜硫酸イオン濃度55を得る。Thus, in the amount 52 of sulfite ions oxidation amount 48 and outflow of sulfite ions can be estimated as inflow 43 of can be estimated sulfite ions SO 2 load 41 the natural oxidation rate 39 to washing column sulfite ions The balance is calculated by the subtractors 49 and 53, whereby the sulfite ion concentration 55 is obtained as the output of the function generator 54 for calculating the sulfite ion concentration in the cleaning liquid.
最後に第３図に示すように、吸収のために必要な亜硫
酸イオンの濃度61をオン・ラインで計測される洗浄塔入
口の亜硫酸ガス濃度31の関数62として算出する。Finally, as shown in FIG. 3, the concentration 61 of the sulfite ion required for the absorption is calculated as a function 62 of the sulfur dioxide concentration 31 at the inlet of the washing tower measured on-line.
このようにしてオン・ライン計測可能な状態量から算
出された洗浄液中のカルシウムイオン濃度（第１図の符
番22）と、洗浄液中の亜硫酸イオン濃度（第２図の符番
55）及び吸収のために必要な亜硫酸イオンの濃度（第３
図の符番61）を第３図に示すように、亜硫酸イオンを硫
酸イオンに酸化せしめるための吹込み空気量と、洗浄塔
からの洗浄液の抜出し量をカスケード制御する際の一次
調節計の制御量の設定値としている。すなわち、予め設
定された最適なカルシウムイオン濃度と亜硫酸イオン濃
度の積63を設定値とし、上記洗浄液中のカルシウムイオ
ン濃度22と亜硫酸イオン濃度55の積64を制御量とする一
次調節計65の出力で洗浄液抜出し量17を調節する二次調
節計66の設定値を補正し、この二次調節計66の出力で洗
浄液抜出し量17の調節弁67を操作する。In this way, the calcium ion concentration in the cleaning liquid calculated from the on-line measurable state quantity (reference numeral 22 in FIG. 1) and the sulfite ion concentration in the cleaning liquid (reference number in FIG. 2)
55) and the concentration of sulfite ions required for absorption (third
As shown in FIG. 3 by reference numeral 61) in the figure, the primary controller controls the cascade control of the blowing air amount for oxidizing the sulfite ion to the sulfate ion and the discharge amount of the cleaning liquid from the cleaning tower. It is the set value of the amount. That is, the output 63 of the primary controller 65, which uses the product 63 of the calcium ion concentration and the sulfite ion concentration set in advance as a set value and the product 64 of the calcium ion concentration 22 and the sulfite ion concentration 55 in the cleaning solution as a control amount. Then, the set value of the secondary controller 66 for adjusting the washing liquid withdrawal amount 17 is corrected, and the control valve 67 for the washing liquid withdrawal amount 17 is operated with the output of the secondary controller 66.
また、上記吸収のために必要な亜硫酸イオンの濃度61
を設定値とし、洗浄液中の亜硫酸イオン濃度55を制御量
とする一次調節計68の出力で吹込み空気量44を調節する
二次調節計69の設定値を補正し、この二次調節計69の出
力で吹込み空気量44の調節弁70を操作する。In addition, the concentration of sulfite ions required for the above absorption 61
Is set as a set value, and the set value of the secondary controller 69 that adjusts the blown air amount 44 with the output of the primary controller 68 that uses the sulfite ion concentration 55 in the cleaning liquid as a control amount is corrected. The control valve 70 for the amount of blown air 44 is operated with the output of.
本制御方法によって、洗浄塔入口亜硫酸ガス濃度の変
動があっても、吸収のために必要な亜硫酸イオンの濃度
をトレースし高脱硫率を確保できると共に、洗浄液の抜
出し量や吹込み量を低減できる。By this control method, even if the concentration of sulfurous acid gas at the inlet of the washing tower fluctuates, the concentration of sulfite ion necessary for absorption can be traced to ensure a high desulfurization rate, and the amount of withdrawal and blowing of the washing liquid can be reduced. .
しかも、排ガス中のSO2負荷に代表される酸負荷の変
動やダスト負荷の変動があっても、スケールトラブルを
生ずることなく、洗浄塔からの洗浄液の抜出し量を低減
し、排水処理をはじめとするランニングコストの低減を
図ることができるという効果がある。Moreover, even if there is variation in the fluctuations and dust load acids load represented by SO 2 load in the exhaust gas, without causing scaling problems, to reduce the withdrawal amount of the cleaning liquid from the washing tower, O beginning to wastewater treatment There is an effect that the running cost can be reduced.
第１図と第２図は本発明のオン・ライン計測可能な状態
量から関数発生器を用いてそれぞれ洗浄液中のカルシウ
ムイオン濃度と洗浄液中の亜硫酸イオン濃度を算出する
手順の一例を示すフローチャート、第３図は本発明の脱
硫設備の制御方法の一例を示すフローチャートであり、
一部、本発明の吸収のために必要な洗浄液中の亜硫酸イ
オンの濃度を算出する手順の一例を示すフローチャート
を含んでいる。また、第４図は、従来の脱硫設備の制御
方法の一例を示すフローチャートである。 4,20,34,49,53:減算器 5,9,10,14,18,35,42,51:掛算器 16:加算器 21,38,47,54:関数発生器 40:演算器 65,68:一次調節計 66,69:二次調節計 71:排ガス入口ダクト 72:洗浄塔 73:ポンプ 74,76:配管 75:抜出し機構FIGS. 1 and 2 are flowcharts showing an example of a procedure for calculating a calcium ion concentration in a cleaning solution and a sulfite ion concentration in a cleaning solution using a function generator from state quantities that can be measured on-line according to the present invention. FIG. 3 is a flowchart showing an example of a method for controlling a desulfurization facility of the present invention,
Partly includes a flowchart showing an example of a procedure for calculating the concentration of sulfite ions in the cleaning solution necessary for absorption according to the present invention. FIG. 4 is a flowchart showing an example of a conventional method for controlling a desulfurization facility. 4,20,34,49,53: Subtractor 5,9,10,14,18,35,42,51: Multiplier 16: Adder 21,38,47,54: Function generator 40: Calculator 65 , 68: Primary controller 66, 69: Secondary controller 71: Exhaust gas inlet duct 72: Washing tower 73: Pump 74, 76: Piping 75: Extraction mechanism
───────────────────────────────────────────────────── フロントページの続き (72)発明者 舟橋 栄次 福岡県北九州市戸畑区大字中原46番地の 59 新日本製鐵株式會社機械・プラント 事業部内 (72)発明者 村越 一毅 福岡県北九州市戸畑区大字中原46番地の 59 新日本製鐵株式會社機械・プラント 事業部内 (72)発明者 高野浦 政継 福岡県北九州市八幡東区枝光１丁目１番 １号 新日本製鐵株式會社設備技術本部 内 (72)発明者 北村 忠彦 福岡県北九州市八幡東区枝光１丁目１番 １号 新日本製鐵株式會社八幡製鐵所内 (72)発明者 渡 清爾 福岡県北九州市戸畑区大字中原46番地の 59 日鐵プラント設計株式会社内 (72)発明者 石川 哲夫 福岡県北九州市戸畑区大字中原46番地の 59 日鐵プラント設計株式会社内 (72)発明者 原田 浩次 福岡県北九州市戸畑区大字中原46番地の 59 日鐵プラント設計株式会社内 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Eiji Funahashi 46-46 Nakahara, Tobata-ku, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Division (72) Inventor Kazuki Murakoshi Tobata, Kitakyushu-shi, Fukuoka Nippon Steel Corporation Machinery & Plant Division, 46, Nakahara, Oita-ku (72) Inventor Tadahiko Kitamura 1-1-1, Edamitsu, Yawatahigashi-ku, Kitakyushu-shi, Fukuoka Prefecture Inside Nippon Steel Corporation Yawata Works (72) Inventor Seiji Watari 46-46 Nakahara, Ogata, Tobata-ku, Kitakyushu-shi, Fukuoka Prefecture (72) Tetsuo Ishikawa, Nippon Steel Plant Design Co., Ltd. Within the company (72) inventor Koji Harada Kitakyushu, Fukuoka Prefecture Tobata-ku, Oaza Nakahara of the address 46 59 Nippon Steel plant design within Co., Ltd.
Claims (1)
グネシウム系洗浄液を循環せしめつつ、気液接触によっ
て排ガスの脱硫を行うに当たり、オン・ライン計測可能
な状態量から関数発生器を用いて洗浄液中のカルシウム
イオン濃度と亜硫酸イオン濃度および吸収のために必要
な洗浄液中の亜硫酸イオンの濃度を算出し、前記算出さ
れた洗浄液中のカルシュウムイオン濃度と洗浄液中の亜
硫酸イオン濃度との積と予め設定される最適なカルシュ
ウムイオン濃度と亜硫酸イオン濃度との積により洗浄塔
からの洗浄液の抜き出し量を操作量とするカスケード制
御と、前記算出された洗浄液中の亜硫酸イオン濃度と吸
収に必要な洗浄液中の亜硫酸イオン濃度とにより洗浄塔
への吹き込み空気量を操作量とするカスケード制御との
二つのカスケード制御をすることを特徴とする排ガス脱
硫設備の制御方法。The present invention relates to a method for desulfurizing exhaust gas by gas-liquid contact while circulating a magnesium-based cleaning solution containing a magnesium compound as a desulfurizing agent. The ion concentration and the sulfite ion concentration and the concentration of the sulfite ion in the washing solution necessary for absorption are calculated, and the product of the calculated calcium ion concentration in the washing solution and the sulfite ion concentration in the washing solution is set to an optimum value set in advance. Cascade control of the amount of the washing solution withdrawn from the washing tower as the manipulated variable by the product of the calcium ion concentration and the sulfite ion concentration, and the calculated sulfite ion concentration in the washing solution and the sulfite ion concentration in the washing solution required for absorption. Cascade with cascade control using the amount of air blown into the washing tower Control method for an exhaust gas desulfurization device, characterized by the control.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1209893A JP2738750B2 (en) | 1989-08-14 | 1989-08-14 | Control method of exhaust gas desulfurization equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1209893A JP2738750B2 (en) | 1989-08-14 | 1989-08-14 | Control method of exhaust gas desulfurization equipment |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH0372912A JPH0372912A (en) | 1991-03-28 |
| JP2738750B2 true JP2738750B2 (en) | 1998-04-08 |
Family
ID=16580393
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1209893A Expired - Fee Related JP2738750B2 (en) | 1989-08-14 | 1989-08-14 | Control method of exhaust gas desulfurization equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2738750B2 (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3150615B2 (en) * | 1996-06-28 | 2001-03-26 | 三菱重工業株式会社 | Oxidation control method in flue gas desulfurization treatment |
| JP4644912B2 (en) * | 2000-06-19 | 2011-03-09 | Ｊｆｅスチール株式会社 | Control method of sintering machine exhaust gas desulfurization equipment |
| US9321025B2 (en) | 2012-05-11 | 2016-04-26 | Alstom Technology Ltd | Oxidation control for improved flue gas desulfurization performance |
| US9321006B2 (en) | 2012-05-11 | 2016-04-26 | Alstom Technology Ltd | Oxidation control for improved flue gas desulfurization performance |
| US10919016B2 (en) | 2017-02-15 | 2021-02-16 | General Electric Technology Gmbh | Oxidation control for improved flue gas desulfurization performance |
| CN115121099A (en) * | 2022-07-14 | 2022-09-30 | 西安热工研究院有限公司 | Integrated online control desulfurization slurry oxidation and wastewater discharge device and method |
-
1989
- 1989-08-14 JP JP1209893A patent/JP2738750B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0372912A (en) | 1991-03-28 |
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