JP2681230B2 - Boiler corrosion inhibitor and corrosion prevention method - Google Patents
Boiler corrosion inhibitor and corrosion prevention methodInfo
- Publication number
- JP2681230B2 JP2681230B2 JP2416209A JP41620990A JP2681230B2 JP 2681230 B2 JP2681230 B2 JP 2681230B2 JP 2416209 A JP2416209 A JP 2416209A JP 41620990 A JP41620990 A JP 41620990A JP 2681230 B2 JP2681230 B2 JP 2681230B2
- Authority
- JP
- Japan
- Prior art keywords
- acid
- boiler
- corrosion
- salts
- water
- 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 - Lifetime
Links
Description
【０００１】[0001]
【産業上の利用分野】この発明は、主として、ボイラに
供給する水のための処理剤であって、とくに高温度の環
境下におかれる缶体内部で金属表面上に強固な防食被膜
を形成することができる組成物、及びこの組成物を用い
た腐食防止方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is mainly a treatment agent for water to be supplied to a boiler, and in particular, forms a strong anticorrosion coating on a metal surface inside a can body which is exposed to a high temperature environment. A composition that can be , and using this composition
It also relates to a method of preventing corrosion .
【０００２】[0002]
【従来の技術】ボイラ用の缶水処理剤には、清缶剤とし
て用いられるものと、脱酸素剤として用いられるものと
の二種がある。このうち、清缶剤は、缶内に浸入する硬
度分や酸化鉄等が缶体内部でスケール化するのを妨げる
とともに、ｐＨ値を適切な範囲に調節して、缶体の腐食
を抑える働きを持っている。一方、脱酸素剤は、缶水中
の溶存酸素を取り除くことにより、防食の機能を達成す
るものである。これら二種の処理剤は、適用すべき水の
性状に応じて適宜併用されている。2. Description of the Related Art There are two types of boiler water treatment agents, one used as a cleansing agent and the other used as a deoxidizer. Of these, the cleaning agent prevents the hardness and iron oxide that enter the can from being scaled inside the can, and adjusts the pH value to an appropriate range to suppress corrosion of the can. have. On the other hand, the oxygen scavenger achieves the anticorrosion function by removing dissolved oxygen in the can water. These two treatment agents are appropriately used in combination depending on the properties of water to be applied.
【０００３】従来の技術によると、前記処理剤の調整に
際して、各種の薬剤を細かく調合することが求められる
ために、コストが高いものとなっている。しかも、脱酸
素剤を適用するときは、供給水の溶存酸素濃度に対応し
た投入量を決定しなければならず、その測定が非常に煩
雑な作業となっている。水中の溶存酸素濃度は、温度等
の外的環境によって大きく変動するが、このことは、脱
酸素剤の投入時に、外的環境条件とともに缶内の脱酸素
成分の残留量をチェックして、総量を調整するという困
難な操作が必要なことを意味している。[0003] According to the prior art, when adjusting the treatment agent, it is required to finely mix various agents, resulting in high costs. In addition, when a deoxidizer is applied, the amount of supply corresponding to the dissolved oxygen concentration of the supply water must be determined, and the measurement is a very complicated operation. The dissolved oxygen concentration in water greatly varies depending on the external environment such as temperature.This is because when the oxygen absorber is added, the residual amount of deoxidized components in the can is checked together with the external environmental conditions to determine the total amount of oxygen. This means that a difficult operation of adjusting is required.
【０００４】前記のような煩雑，かつ困難な操作を省く
簡略的な手法として、脱酸素剤の投入量を年間を通じて
最も溶存酸素濃度の高い時期に設定しておくことが試み
られている。しかし、この場合、溶存酸素濃度の低い時
期では薬剤が過剰となり、コスト高になる。また、亜硫
酸系の脱酸素剤では、過剰分の薬剤が缶水の電気伝導度
を高めて、ブロー処理（缶内に生じた濃縮水の排出処
理）の機会を増やすのみならず、キャリオーバーの原因
となる。同様な不具合は、ヒドラジン系の脱酸素剤でも
起こり得る。さらに、従来の脱酸素剤には、保管中に空
気中の酸素と反応して劣化することや、長期保存によっ
て変質する等の欠点があることも知られている。[0004] As a simple method for eliminating the complicated and difficult operations as described above, attempts have been made to set the amount of the oxygen absorber to be supplied at a time when the dissolved oxygen concentration is highest throughout the year. However, in this case, when the dissolved oxygen concentration is low, the drug becomes excessive and the cost increases. In addition, in the case of a sulfurous acid type oxygen scavenger, excess chemicals increase the electrical conductivity of the can water, increasing not only the chance of blow processing (the processing of discharging concentrated water generated in the can), but also the carryover. Cause. Similar problems can occur with hydrazine-based oxygen scavengers. Further, it is also known that conventional oxygen scavengers have disadvantages such as deterioration due to reaction with oxygen in the air during storage and deterioration due to long-term storage.
【０００５】[0005]
【発明が解決しようとする課題】一般に、前記清缶剤あ
るいは脱酸素剤は、多種類の成分を混有していて、各成
分の相乗作用によって所期の目的（スケール抑制機能並
びに脱酸素機能）を達成しているけれども、それら公知
の成分は、先に述べたようなコスト上の不利益や取扱上
の困難性に結びつく。このような問題点は、缶体内部
で、缶壁ないしは水管壁に対して充分かつ強固な防食被
膜を形成することができれば、自ずと解消することにな
る。Generally, the cleaning agent or the oxygen scavenger contains various types of components, and the desired purpose (scale suppression function and deoxygenation function) is achieved by synergistic action of each component. ), But these known components lead to cost disadvantages and handling difficulties as described above. Such a problem can be solved by itself if a sufficient and strong anticorrosion coating can be formed on the wall of the can or the wall of the water tube inside the can.
【０００６】[0006]
【課題を解決するための手段】そこで、発明者は、前記
着眼点に基づき、缶体を構成している鉄系金属材料の表
面上にキレートの緻密な防食被膜を形成することについ
て、多くの試策と実験を行った結果、カルボキシル基を
２個以上持つ有機多塩基酸またはその塩のうちから選ば
れる１種以上の成分を含む組成物がボイラ用缶水処理剤
として好適なことを見出したものである。Therefore, based on the above-mentioned point of view, the inventor has made many proposals for forming a dense anticorrosion coating of a chelate on the surface of the iron-based metal material constituting the can body. As a result of trials and experiments, it was found that a composition containing one or more components selected from organic polybasic acids having two or more carboxyl groups or salts thereof is suitable as a boiler water treatment agent. It is a thing.
【０００７】この発明における有機多塩基酸には、コハ
ク酸，リンゴ酸，フマル酸，酒石酸等、２つのカルボキ
シル基を持つものや、クエン酸，イソクエン酸等、３つ
以上のカルボキシル基を持つものが挙げられる。Organic polybasic acids used in the present invention include those having two carboxyl groups such as succinic acid, malic acid, fumaric acid and tartaric acid, and those having three or more carboxyl groups such as citric acid and isocitric acid. Is mentioned.
【０００８】また、塩を形成する金属イオンとしては、
Ｎａ+ ，Ｋ+ ，Ｌｉ+ 等のアルカリ金属イオンの他、Ｃ
ａ2+，Ｍｇ2+等のアルカリ土類金属イオン等が挙げられ
るが、溶解度が高い点あるいはスケール化防止の点で
は、後者のアルカリ金属を用いる方がより好ましい結果
が得られる。Further, as the metal ion forming a salt,
In addition to alkali metal ions such as Na + , K + , and Li + ,
Examples thereof include alkaline earth metal ions such as a 2+ and Mg 2+. From the viewpoint of high solubility or prevention of scaling, the use of the latter alkali metal provides more preferable results.
【０００９】そして、この発明における缶水処理剤は、
水溶液等の溶液もしくは粉末の形態のいずれでも使用可
能である。Further, the can water treatment agent in the present invention is
Any form of a solution such as an aqueous solution or a powder can be used.
【００１０】[0010]
【実施例】この発明の具体的実施例について説明する
と、下記の表１と表２は、カルボキシル基が２つと３つ
の有機多塩基酸の使用例をそれぞれ表している。EXAMPLES Specific examples of the present invention will be described. Tables 1 and 2 below show examples of use of organic polybasic acids having two and three carboxyl groups, respectively.
【００１１】 [0011]
【００１２】 [0012]
【００１３】この発明による缶水処理剤の場合、その防
食のメカニズムは、鉄イオンと有機多塩基酸またはその
イオンが沈澱を生じて金属表面に吸着により薄膜を形成
した状態となり、あるいは有機多塩基酸またはそのイオ
ンが金属表面でキレートの緻密な薄膜を形成した状態と
なることによるものと推定される。したがって、缶体内
部に形成すべき防食被膜は、現実的には缶水中に一定濃
度（量）以上の有機多塩基酸またはその塩を維持するこ
とによって実現することができ、供給水の溶存酸素濃度
には左右されない。この傾向は、溶存酸素濃度と金属表
面上の発生孔食数との関係を示す図１から理解すること
ができる。In the case of the water treatment agent according to the present invention, the mechanism of anticorrosion is as follows: iron ions and organic polybasic acids or their ions are precipitated to form a thin film by adsorption on the metal surface; It is presumed that the acid or its ion is in a state of forming a dense chelate thin film on the metal surface. Therefore, the anticorrosion film to be formed inside the can body can be actually realized by maintaining an organic polybasic acid or a salt thereof at a certain concentration (amount) or more in the can water. It does not depend on the concentration. This tendency can be understood from FIG. 1 showing the relationship between the dissolved oxygen concentration and the number of generated pits on the metal surface.
【００１４】図１によれば、この発明の処理剤の使用に
より、缶水中の溶存酸素濃度が高くなっても、水管等の
内壁の金属表面上の孔食数の発生状態に大きな変化が現
れないことが判る。According to FIG. 1, by using the treating agent of the present invention, even if the dissolved oxygen concentration in the can water becomes high, a large change appears in the generation state of the number of pitting corrosion on the metal surface of the inner wall of the water pipe or the like. I know there isn't.
【００１５】そして、図２によれば、この発明の処理剤
によって得られる別の作用，すなわち缶体外部から持ち
込まれるスケール成分（硬度分や酸化鉄等）のスケール
化（缶壁等へのスケール成分の付着，生長）を抑制する
作用が示されている。この図２は、ボイラの燃焼（稼
動）時間の増加に伴って、金属表面上に発生するスケー
ルの厚みを表したものであり、この図２により、この発
明の処理剤のスケール化抑制作用が従来の亜硫酸系の処
理剤よりも顕著であること、および薬品無添加の場合に
比し、スケール発生量の点でも著しく優位であることが
理解される。According to FIG. 2, another effect obtained by the treatment agent of the present invention, that is, scaling of scale components (hardness, iron oxide, etc.) brought in from outside the can body (scale on the can wall, etc.) It has been shown to suppress the adhesion and growth of components). This FIG. 2 shows the thickness of the scale generated on the metal surface with the increase of the combustion (operating) time of the boiler. This FIG. 2 shows that the treatment agent of the present invention has a scaling inhibiting effect. It is understood that it is more remarkable than the conventional sulfite-based treating agent, and that it is significantly superior in terms of scale generation amount as compared with the case where no chemical is added.
【００１６】[0016]
【発明の効果】以上のように、この発明のボイラ用缶水
処理剤組成物は、缶体内部の金属表面上に強固な防食被
膜を形成して、溶存酸素濃度にほとんど影響されること
なく、所望の防食機能を発揮するものである。また、従
来のような煩雑な薬剤の調合，溶存酸素濃度の管理等の
煩雑な操作が不要で、最初に所定の投入量を設定して、
次回以降その量を維持するだけでよい。さらに、缶内処
理剤として従来必要としていたリン酸，ポリカルボン酸
等のスケール抑制剤を配合する必要がなく、処理剤全体
の成分数を少なくして、製品コストを大幅に低減するこ
とができる。この他、前記有機多塩基酸が粉末もしくは
水溶液でも化学的に安定であることにより、脱酸素剤と
しての亜硫酸塩やヒドラジンに見られるような劣化の心
配がなく、保管に要する費用を軽減することもできる。As described above, the boiler can water treatment composition of the present invention forms a strong anticorrosion coating on the metal surface inside the can body, and is hardly affected by the dissolved oxygen concentration. , Exhibits a desired anticorrosion function. In addition, there is no need for complicated operations such as complicated preparation of chemicals and management of dissolved oxygen concentration as in the conventional case.
All you have to do is maintain that amount next time. Furthermore, there is no need to incorporate a scale inhibitor such as phosphoric acid or polycarboxylic acid, which was conventionally required as a treatment agent in a can, and the number of components in the entire treatment agent can be reduced, thereby greatly reducing product cost. . In addition, since the organic polybasic acid is chemically stable even in powder or aqueous solution, there is no need to worry about deterioration such as in sulfites and hydrazines as oxygen scavengers, and the cost required for storage can be reduced. Can also.
【図１】水中の溶存酸素濃度と金属表面上に発生する孔
食数との関係を示す説明図である。FIG. 1 is an explanatory diagram showing the relationship between the concentration of dissolved oxygen in water and the number of pits generated on a metal surface.
【図２】ボイラの燃焼（稼動）時間と缶体内部に発生す
るスケールの厚みとの関係を示す説明図である。FIG. 2 is an explanatory diagram showing a relationship between a boiler combustion (operation) time and a scale thickness generated inside a can body.
フロントページの続き (56)参考文献 特開 昭48−95330（ＪＰ，Ａ) 特開 昭51−59447（ＪＰ，Ａ) 特開 平１−212781（ＪＰ，Ａ) 特開 昭55−106589（ＪＰ，Ａ) 特公 昭28−6351（ＪＰ，Ｂ１) 特公 昭49−18338（ＪＰ，Ｂ１)Continuation of the front page (56) Reference JP-A-48-95330 (JP, A) JP-A-51-59447 (JP, A) JP-A 1-212781 (JP, A) JP-A-55-106589 (JP , A) JP-B 28-6351 (JP, B1) JP-B 49-18338 (JP, B1)
Claims (4)
用する組成物であって、カルボキシル基を２個以上持つ
有機多塩基酸又はその塩から選ばれる１種以上を主成分
とし、タンニン酸及びその塩は含まないボイラの腐食防
止剤。 1. A composition to be used by adding it to boiler can water during boiler operation, which comprises, as a main component, at least one selected from organic polybasic acids having two or more carboxyl groups or salts thereof, and tannic acid. Boiler corrosion protection
Stop agent.
５個持っている請求項１に記載のボイラの腐食防止剤。 2. The organic polybasic acid has a methylene group of 0 to
The boiler corrosion inhibitor according to claim 1, which has five of them .
酸、フマル酸、酒石酸、クエン酸、イソクエン酸のいず
れかである請求項１に記載のボイラの腐食防止剤。 3. The boiler corrosion inhibitor according to claim 1, wherein the organic polybasic acid is any one of succinic acid, malic acid, fumaric acid, tartaric acid, citric acid, and isocitric acid .
基酸又はその塩から選ばれる１種以上を主成分とし、タ
ンニン酸及びその塩を含まない組成物を、 ボイラ運転時にボイラ缶水に添加するボイラの腐食防止
方法 。4. An organic polysalt having two or more carboxyl groups
Based on one or more selected from basic acids or salts thereof,
Addition of a composition that does not contain phosphonic acid and its salts to boiler boiler water during boiler operation.
How .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2416209A JP2681230B2 (en) | 1990-12-28 | 1990-12-28 | Boiler corrosion inhibitor and corrosion prevention method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2416209A JP2681230B2 (en) | 1990-12-28 | 1990-12-28 | Boiler corrosion inhibitor and corrosion prevention method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04232285A JPH04232285A (en) | 1992-08-20 |
| JP2681230B2 true JP2681230B2 (en) | 1997-11-26 |
Family
ID=18524450
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2416209A Expired - Lifetime JP2681230B2 (en) | 1990-12-28 | 1990-12-28 | Boiler corrosion inhibitor and corrosion prevention method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2681230B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003073865A (en) * | 2001-08-30 | 2003-03-12 | Katayama Chem Works Co Ltd | Treatment method for water in boiler |
| JP2011214096A (en) * | 2010-03-31 | 2011-10-27 | Kurita Water Ind Ltd | Boiler water treatment agent and method for preventing corrosion of boiler |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5145916B2 (en) * | 2007-12-18 | 2013-02-20 | 東亜ディーケーケー株式会社 | Electrolyte for polarographic diaphragm electrode and polarographic diaphragm electrode |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4918338A (en) * | 1972-06-12 | 1974-02-18 | ||
| JPH01212781A (en) * | 1988-02-18 | 1989-08-25 | Kurita Water Ind Ltd | Corrosion inhibitor |
-
1990
- 1990-12-28 JP JP2416209A patent/JP2681230B2/en not_active Expired - Lifetime
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003073865A (en) * | 2001-08-30 | 2003-03-12 | Katayama Chem Works Co Ltd | Treatment method for water in boiler |
| JP2011214096A (en) * | 2010-03-31 | 2011-10-27 | Kurita Water Ind Ltd | Boiler water treatment agent and method for preventing corrosion of boiler |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH04232285A (en) | 1992-08-20 |
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