JPH01316478A - Detergent for calcium sulfate scale - Google Patents
Detergent for calcium sulfate scaleInfo
- Publication number
- JPH01316478A JPH01316478A JP14701688A JP14701688A JPH01316478A JP H01316478 A JPH01316478 A JP H01316478A JP 14701688 A JP14701688 A JP 14701688A JP 14701688 A JP14701688 A JP 14701688A JP H01316478 A JPH01316478 A JP H01316478A
- Authority
- JP
- Japan
- Prior art keywords
- calcium sulfate
- scale
- acid
- detergent
- cleaning
- 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.)
- Pending
Links
- OSGAYBCDTDRGGQ-UHFFFAOYSA-L calcium sulfate Chemical compound [Ca+2].[O-]S([O-])(=O)=O OSGAYBCDTDRGGQ-UHFFFAOYSA-L 0.000 title claims abstract description 54
- 239000003599 detergent Substances 0.000 title abstract 4
- 239000002253 acid Substances 0.000 claims abstract description 15
- 238000005260 corrosion Methods 0.000 claims abstract description 11
- 230000007797 corrosion Effects 0.000 claims abstract description 11
- 239000003112 inhibitor Substances 0.000 claims abstract description 10
- 239000003002 pH adjusting agent Substances 0.000 claims abstract 4
- 239000012459 cleaning agent Substances 0.000 claims description 9
- 239000011259 mixed solution Substances 0.000 claims 1
- 239000003795 chemical substances by application Substances 0.000 abstract description 11
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 abstract description 9
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 abstract description 5
- 239000003513 alkali Substances 0.000 abstract description 5
- 238000010438 heat treatment Methods 0.000 abstract description 3
- 239000004094 surface-active agent Substances 0.000 abstract description 2
- 230000001105 regulatory effect Effects 0.000 abstract 2
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 abstract 1
- 235000011132 calcium sulphate Nutrition 0.000 description 22
- 229940095672 calcium sulfate Drugs 0.000 description 21
- 238000004140 cleaning Methods 0.000 description 18
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 8
- 238000000034 method Methods 0.000 description 7
- 239000013535 sea water Substances 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 5
- 239000011575 calcium Substances 0.000 description 5
- 229910052791 calcium Inorganic materials 0.000 description 5
- 150000007522 mineralic acids Chemical class 0.000 description 5
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 4
- 230000007423 decrease Effects 0.000 description 4
- 238000010612 desalination reaction Methods 0.000 description 4
- 238000004090 dissolution Methods 0.000 description 4
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 4
- 150000007524 organic acids Chemical class 0.000 description 4
- 235000005985 organic acids Nutrition 0.000 description 4
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000007788 liquid Substances 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000001556 precipitation Methods 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- OSWFIVFLDKOXQC-UHFFFAOYSA-N 4-(3-methoxyphenyl)aniline Chemical compound COC1=CC=CC(C=2C=CC(N)=CC=2)=C1 OSWFIVFLDKOXQC-UHFFFAOYSA-N 0.000 description 2
- KXDHJXZQYSOELW-UHFFFAOYSA-N Carbamic acid Chemical compound NC(O)=O KXDHJXZQYSOELW-UHFFFAOYSA-N 0.000 description 2
- QPCDCPDFJACHGM-UHFFFAOYSA-N N,N-bis{2-[bis(carboxymethyl)amino]ethyl}glycine Chemical compound OC(=O)CN(CC(O)=O)CCN(CC(=O)O)CCN(CC(O)=O)CC(O)=O QPCDCPDFJACHGM-UHFFFAOYSA-N 0.000 description 2
- QAOWNCQODCNURD-UHFFFAOYSA-L Sulfate Chemical compound [O-]S([O-])(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-L 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 150000001412 amines Chemical class 0.000 description 2
- 229940095564 anhydrous calcium sulfate Drugs 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 229910000019 calcium carbonate Inorganic materials 0.000 description 2
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 2
- 239000000920 calcium hydroxide Substances 0.000 description 2
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 235000019253 formic acid Nutrition 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 239000010931 gold Substances 0.000 description 2
- 229910052737 gold Inorganic materials 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- LNOPIUAQISRISI-UHFFFAOYSA-N n'-hydroxy-2-propan-2-ylsulfonylethanimidamide Chemical compound CC(C)S(=O)(=O)CC(N)=NO LNOPIUAQISRISI-UHFFFAOYSA-N 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- URDCARMUOSMFFI-UHFFFAOYSA-N 2-[2-[bis(carboxymethyl)amino]ethyl-(2-hydroxyethyl)amino]acetic acid Chemical compound OCCN(CC(O)=O)CCN(CC(O)=O)CC(O)=O URDCARMUOSMFFI-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- 229910052925 anhydrite Inorganic materials 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 235000013405 beer Nutrition 0.000 description 1
- 239000013522 chelant Substances 0.000 description 1
- YZIYKJHYYHPJIB-UUPCJSQJSA-N chlorhexidine gluconate Chemical compound OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O.OC[C@@H](O)[C@@H](O)[C@H](O)[C@@H](O)C(O)=O.C1=CC(Cl)=CC=C1NC(=N)NC(=N)NCCCCCCNC(=N)NC(=N)NC1=CC=C(Cl)C=C1 YZIYKJHYYHPJIB-UUPCJSQJSA-N 0.000 description 1
- 230000003750 conditioning effect Effects 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 230000000668 effect on calcium Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- VTHJTEIRLNZDEV-UHFFFAOYSA-L magnesium dihydroxide Chemical compound [OH-].[OH-].[Mg+2] VTHJTEIRLNZDEV-UHFFFAOYSA-L 0.000 description 1
- 239000000347 magnesium hydroxide Substances 0.000 description 1
- 229910001862 magnesium hydroxide Inorganic materials 0.000 description 1
- 235000012254 magnesium hydroxide Nutrition 0.000 description 1
- 239000002075 main ingredient Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical compound OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
- 229960003330 pentetic acid Drugs 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 239000000843 powder Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23G—CLEANING OR DE-GREASING OF METALLIC MATERIAL BY CHEMICAL METHODS OTHER THAN ELECTROLYSIS
- C23G1/00—Cleaning or pickling metallic material with solutions or molten salts
- C23G1/14—Cleaning or pickling metallic material with solutions or molten salts with alkaline solutions
Landscapes
- Chemical & Material Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- General Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Mechanical Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Detergent Compositions (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は蒸発式海水淡水化装置及び海水冷却装置の伝熱
面に析出、付着した硫酸カルシウムを主成分とするスケ
ールを溶解除去するための洗浄剤に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention is a method for dissolving and removing scale mainly composed of calcium sulfate that has precipitated and adhered to the heat transfer surfaces of evaporative seawater desalination equipment and seawater cooling equipment. Regarding cleaning agents.
伝熱面に析出、付着するスケールがｃｈｃｏｓａＭｇ
（ＯＨ）２等のアルカリスケールであれば塩酸、硫酸等
の無機酸あるいは＠酸、スルファミン酸等の有機酸によ
って溶解除去できるが、特に硫酸カルシウムを主成分と
する硬質スケールの除去は次の１すな複雑な方法であつ
九。The scale that precipitates and adheres to the heat transfer surface is chcosaMg.
Alkaline scales such as (OH)2 can be dissolved and removed using inorganic acids such as hydrochloric acid and sulfuric acid, or organic acids such as @acid and sulfamic acid, but especially hard scales whose main component is calcium sulfate can be removed by the following method. In a complicated way.
硫酸カルシウムを第１式に示すよう高温の高アルカリで
炭酸カルシウムと水酸化カルシウムに転換した後、第２
弐に示すように無機酸と反２ Ｃ＆８０４ ＋Ｎａ２Ｃ
ｏ、 ＋ ２ＮａＯＩＩＩ −−→ＣａＣ０，−Ｈａ（
ＯＨ）２＋２Ｎ＆２８０４・−−−−−第１式％式％
２ ＣａＣ／２＋４Ｈ２０＋ＣＯ２↑・・・・・・第２
式しかしながら、第１式の反応で硫酸カルシウムスケー
ルの内部までアルカリが浸透せず、表面だけしか炭酸カ
ルシウムと水酸化カルシウムとに転換しないため、第１
式及び第２式の反応を何度も繰り返さないと完全な溶解
はできなかつ几。After converting calcium sulfate into calcium carbonate and calcium hydroxide with high temperature and high alkali as shown in the first equation, the second
As shown in 2, inorganic acid and anti-2C&804 +Na2C
o, + 2NaOIII −-→CaC0, −Ha(
OH)2+2N&2804・----1st formula% formula% 2 CaC/2+4H20+CO2↑・・・・・・2nd
However, in the reaction of the first equation, the alkali does not penetrate into the inside of the calcium sulfate scale, and only the surface is converted into calcium carbonate and calcium hydroxide.
Complete dissolution cannot be achieved unless the reactions of formula and formula 2 are repeated many times.
海水淡水化の方法は蒸発法、冷凍法、膜性など数多く開
発されているが、現在最も実用化の進んでいる方式は蒸
発方式である。蒸発式海水淡水化装置での宿命的な問題
として、伝熱面へのスケール析出、付着により伝熱ｔ−
阻害し、装置の熱効率の低下、更にはプラントの運転停
止をひき起す恐れがあげられる。A number of methods have been developed for seawater desalination, including evaporation, freezing, and membrane methods, but the evaporation method is currently the most widely used method. A fateful problem with evaporative seawater desalination equipment is that scale precipitation and adhesion on the heat transfer surface reduce heat transfer.
There is a risk that the thermal efficiency of the equipment will be degraded and the plant may be shut down.
伝熱を阻害するスケールにはアルカリスケール［ｃａｃ
ｏ２． Ｍｇ（ＯＨ）２］と硫酸カルシウム（ＣａＳＯ
４・２Ｈ２０，Ｃａ８０４’％Ｈ２０，ＣａＳＯ４）で
あるが、アルカリスケールの析出防止についてはｅＲｔ
海水に添加して脱炭酸するーコントロール技術が確立さ
れ１、すでに実用化されているので問題はなくなつ几。Alkaline scale [cac] is a scale that inhibits heat transfer.
o2. Mg(OH)2] and calcium sulfate (CaSO
4・2H20, Ca804'%H20, CaSO4), but eRt
Adding it to seawater to decarboxylate it - the control technology has been established and is already in practical use, so there should be no problems.
一方硫酸カルシウムの中でも無水塩は伝熱面に析出し易
く、アルカリスケールのように根本的な析出防止法がな
いので、硫酸カルシウムを主成分とするスケールの析出
、付着によシ伝熱を阻害した場合は、物理的方法によっ
て除去するが付着が甚しい場合は伝熱部を取シ替える必
要がある。On the other hand, among calcium sulfates, anhydrous salts tend to precipitate on heat transfer surfaces, and unlike alkali scales, there is no fundamental method to prevent precipitation, so the precipitation and adhesion of scales whose main component is calcium sulfate inhibits heat transfer. If this occurs, it can be removed by physical methods, but if the adhesion is severe, the heat transfer part must be replaced.
本発明はかかる現状に鑑み、伝熱面スケールを完全にか
つ効率的に溶解除去できる化学的洗浄剤全提供しょうと
するものでおる。In view of the current situation, the present invention aims to provide a chemical cleaning agent capable of completely and efficiently dissolving and removing scale on heat transfer surfaces.
〔課題を解決するための手段〕
本発明はアミノポリカルボン酸、−調整剤及び腐食抑制
剤よシなる−１１へ１２の混合液よりなることを特徴と
する硫酸カルシウムスケール洗浄剤である。[Means for Solving the Problems] The present invention is a calcium sulfate scale cleaning agent comprising a mixture of aminopolycarboxylic acid, a conditioner, and a corrosion inhibitor.
本発明におけるアミノポリカルボン酸としては、エチレ
ンジアミン四酢酸（以下、ｇ Ｄ Ｔ Ａと略す）、ニ
トリロ三酢＃１（以下、ＮＴＡと略す）ヒドロキシエチ
ルエチレンジアミン三酢ｒ！Ｒ（以下、ＨＩＥＤＴＡと
略す〕、ジエチレントリアミン五酢酸（以下、ＤＴＰＡ
と略す）、トリエチレンナト２ミン六酢酸（以下、ＴＴ
ＨＡと略す）等があげられ、これらのアミノポリカルボ
ン酸の少なくとも一棟以上がスラリー液として使用され
る。Examples of the aminopolycarboxylic acids in the present invention include ethylenediaminetetraacetic acid (hereinafter abbreviated as gDTA), nitrilotriacetic acid #1 (hereinafter abbreviated as NTA), hydroxyethylethylenediaminetriacetic acid r! R (hereinafter abbreviated as HIEDTA), diethylenetriaminepentaacetic acid (hereinafter DTPA)
(hereinafter referred to as TT), triethylenenatodiminehexaacetic acid (hereinafter referred to as TT)
(abbreviated as HA), etc., and at least one of these aminopolycarboxylic acids is used as a slurry liquid.
一調整剤としては、上記スラリーの−を１１〜１２に調
整することができるアルカリ剤ならば任意のものが使用
し得るが、例ｔ−６ければ、水酸化ナトリウム、水酸化
カリウム、モノエタノールアミン、ジェタノールアミン
、トリエタノールアミンなどがある。As the adjusting agent, any alkaline agent that can adjust the - of the slurry to 11 to 12 can be used, but in Example t-6, sodium hydroxide, potassium hydroxide, monoethanol These include amines, jetanolamine, and triethanolamine.
腐食抑制剤も公知の任意のものが使用できるが、例えば
杉村化学工業株式会社製の主成分がアミノ誘導体及び界
面活性剤ニジなるヒビｏ７に−４、ヒビロンに−４００
及びヒビロンに−４２０などが使用できる。Any known corrosion inhibitor can be used, but for example, Hibi O7-4 and Hibiron-400 manufactured by Sugimura Chemical Industry Co., Ltd., whose main ingredients are amino derivatives and surfactants, are used.
and -420 can be used for Hibilon.
本発明の洗浄剤は温度７０〜９５℃の範囲で便用するこ
とにより、硫酸カルシウムを主成分とするｌｉｊ！質ス
ケールに対し非常にすぐれ７を溶解力がある。By using the cleaning agent of the present invention at a temperature in the range of 70 to 95°C, the cleaning agent containing calcium sulfate as a main component can be removed. It has a very good dissolving power of 7 on the quality scale.
また洗浄時期及び方法としては、海水淡水化装置及び海
水冷却装置の伝熱面にスケールが析出、付層して熱効率
が低下しはじめ友ら装置１１−時停止して、上記洗浄液
を洗浄部に薬注ポンプで注入し、循環ポンプで循環しな
がら洗浄液温度′ｆｔ７０〜９５℃に保持して伝熱面に
析出、付層し友硫酸カルシウム全主成分とする硬質スケ
ール金浴解除去するＬうにすればよい。In addition, regarding the timing and method of cleaning, scale is deposited on the heat transfer surface of the seawater desalination equipment and seawater cooling equipment, and when the thermal efficiency begins to decrease due to the formation of a layer, the equipment must be stopped at 11-000, and the above cleaning liquid is applied to the cleaning section. Injected with a chemical dosing pump and kept at a cleaning solution temperature of 70 to 95°C while being circulated by a circulation pump, the hard scale deposited on the heat transfer surface, layered, and composed entirely of calcium friend sulfate is removed by gold bath decomposition. do it.
本発明の洗浄剤にＬる硫酸カルシウムスケールの溶解力
及び浴解濾はアミノポリカルボン酸濃度に左右されるの
で、その濃度は洗浄対象物に析出、付着し次硫酸カルシ
ウムのスケール量によって決定されるが、効果的な洗浄
を達成する几めには５〜１５重量％の濃度が好ましい。The dissolving power of calcium sulfate scale and bath filtration in the cleaning agent of the present invention depend on the aminopolycarboxylic acid concentration, so the concentration is determined by the amount of calcium hyposulfate scale that has precipitated and adhered to the object to be cleaned. However, a concentration of 5 to 15% by weight is preferred to achieve effective cleaning.
−調整剤として使用されるアルカリ剤そのものは硫酸カ
ルシウムスケールに対して溶解作用は全くないが、これ
らアルカリ剤金アミノポリカルボン酸に併用添加するこ
とにより、アミノポリカルボン酸の水に対する溶解度を
増すのとそれによる硫酸カルシウムスケールの間接的溶
解助剤として大きな役目を果すものである。例えば上記
アルカリ剤全添加して−を１１以上に＃＃整しておけば
、アミノカルボン酸が硫酸塩のカルシウムに当量分反応
消費尽くシ友としても洗浄液の−が７を切ることはない
ので、硫酸カルシクムスクールの溶解力は最後１で持続
発揮される。-Although the alkaline agents themselves used as conditioning agents have no dissolving effect on calcium sulfate scale, adding these alkaline agents to gold aminopolycarboxylic acid together can increase the solubility of the aminopolycarboxylic acid in water. It plays a major role as an indirect dissolution aid for calcium sulfate scale. For example, if all of the above alkaline agents are added and - is adjusted to 11 or more, the - of the cleaning solution will not fall below 7 even if the aminocarboxylic acid reacts and consumes an equivalent amount to calcium sulfate. The dissolving power of calcium sulfate school is continuously demonstrated in the last step.
−が７以下になると硫酸カルシウムの溶解力は低下し、
ｐＩ′ｉ５以下まで下がると硫酸カルシウムの溶解は殆
んど進１なくなる。洗浄時にｐＨ４が低下してくるのは
、本発明洗浄剤中のアミノポリカルボン酸によって硫酸
カルシウムが溶出されると、カルシウムとアミノカルボ
ン酸は強力な可溶性の錯塩を形成するので、硫酸が遊離
して−が低下する。アルカリ剤によって一上限を１２に
したのは、それ以上に上げても硫酸カルシウムスケール
に対する溶解力に変化がないので経済性を考慮した。When - becomes 7 or less, the dissolving power of calcium sulfate decreases,
When the pI'i drops below 5, the dissolution of calcium sulfate hardly progresses. The reason why pH 4 decreases during cleaning is that when calcium sulfate is eluted by the aminopolycarboxylic acid in the cleaning agent of the present invention, calcium and aminocarboxylic acid form a strong soluble complex salt, so sulfuric acid is liberated. - decreases. The reason why the upper limit was set to 12 by using an alkaline agent was taken into consideration from economical point of view, since there is no change in the dissolving power for calcium sulfate scale even if the alkaline agent is increased beyond that level.
硫酸カルシウム全生成分とするスケールを溶解除去する
ときの効果的洗浄温度は高温になるほど工いが、実用上
７０Ｓ９５℃の範囲内で十分である。The higher the effective cleaning temperature when dissolving and removing scale, which is a total component of calcium sulfate, but the higher the temperature, the more effective it is, but for practical purposes, a range of 70S95°C is sufficient.
ｌた本発明の況浄剤には腐食抑制剤全添加する必要があ
るが、腐食抑制剤としては、それが鋼材に対して腐食抑
制効果を奏するものならば前述したように、公知の腐食
抑制剤が適宜選択して使用し得る。使用濃度は０．３％
程度で十分である。In addition, it is necessary to completely add a corrosion inhibitor to the cleaning agent of the present invention, but as a corrosion inhibitor, if it has a corrosion inhibiting effect on steel materials, as described above, known corrosion inhibitors may be used. A suitable agent can be selected and used. The concentration used is 0.3%
It is enough.
本発明において使用するアミノポリカルボン酸と−ｌ調
整のためのアルカリ剤混合液による硫酸カルシウムスケ
ールの溶解作用は、アミノポリカルボン酸としてＥＤＴ
Ａ７ｐｌ’ｌ調整剤として水酸化ナトリクム全例にとっ
て説明すると、−１１−１２の範囲においてＩ！ｉ Ｄ
ＴＡのカルシウムに対するキレート形成は下記第３式に
示すように作用し、カルシウムの硫酸塩スケール全効果
的に溶解″するものと考えられる。The dissolving action of calcium sulfate scale by the aminopolycarboxylic acid used in the present invention and the alkali agent mixture for -l adjustment is as follows: EDT as the aminopolycarboxylic acid
For all examples of sodium hydroxide as an A7pl'l regulator, I! in the range of -11-12! iD
It is believed that the chelate formation of TA with respect to calcium acts as shown in the third equation below, and that the entire sulfate scale of calcium is effectively dissolved.
ｃａ８０４＋Ｎｔ４Ｙ −＋ Ｎｌ、’ＣＩＬＹ２−
＋Ｎ＆２８Ｑ４−−−−−−第３式ｆｔ タＬ Ｎａ
４Ｙ ：エチレンジアミン四酢酸の四ナトリウム塩（ｐ
ｉ（１１〜１２）
Ｙ：エチレンジアミン四酢酸の陰
イオン
〔実施例〕
第１表に本発明の一実施例である試験結果金示す。ca804+Nt4Y −+ Nl,'CILY2−
+N & 28Q4----3rd formula ft Ta L Na
4Y: Tetrasodium salt of ethylenediaminetetraacetic acid (p
i(11-12) Y: Anion of ethylenediaminetetraacetic acid [Example] Table 1 shows the test results as an example of the present invention.
第１表に示し几組成の洗浄液１００ａｌｔ−２００縦の
ビー力にとり、これに無水硫酸カルシウム２．２５．９
の錠剤（市販の無水硫酸カルシウム粉末２．２５．９を
φ２０Ｘｔ３１１１の成型器に入れて油圧機で１ｏ ｏ
＊ｇ７ａｐ；’まで加圧成型後、９００℃の電気炉で
焼結したもの）１〜３錠を入れ、加熱板付きスタン−上
に置いて回転子で洗浄液を攪拌しながら所定の温度に維
持して硫酸カルシウム錠剤が完全に溶解するまでの時間
を求めた。完全に溶解しないものについては原子吸光光
度計により定量分析を行ってその溶解率を求めた。The cleaning solution with the composition shown in Table 1 was added to 100 alt-200 vertical beer force, and anhydrous calcium sulfate 2.25.9
Tablets (commercially available anhydrous calcium sulfate powder 2.25.9) were put into a φ20Xt3111 molding machine and molded using a hydraulic machine.
* After pressure molding to g7ap;', sintered in an electric furnace at 900℃) 1 to 3 tablets are placed on a stand with a heating plate and the cleaning liquid is stirred with a rotor to maintain the specified temperature. The time required for the calcium sulfate tablet to completely dissolve was determined. For those that were not completely dissolved, quantitative analysis was performed using an atomic absorption spectrophotometer to determine the dissolution rate.
また比較の几め第２表に示す塩酸、硫酸等の無機酸及び
蟻酸、スルファミノ酸等の有機酸にＬる洗浄効果につい
ても行った。In addition, the cleaning effects of inorganic acids such as hydrochloric acid and sulfuric acid and organic acids such as formic acid and sulfamic acid shown in Table 2 were also compared.
本発明にニジ次のような効果を奏する。 The present invention has the following effects.
（１） アミノポリカルボン酸にｐＨＭ１４整剤を添
加して≠金１１〜１２の範囲内に調整したことにエフ、
アミノポリカルボン酸の硫酸カルシウムスケールに対す
る溶解は有効に作用するので、従来の塩酸、硫酸等の無
機酸洗浄や蟻酸、スル７アミノ酸等の有機酸洗浄にくら
べ、はるかに効率しく洗浄ができる。(1) F.
Since aminopolycarboxylic acid dissolves calcium sulfate scale effectively, cleaning can be done much more efficiently than conventional cleaning with inorganic acids such as hydrochloric acid and sulfuric acid, and cleaning with organic acids such as formic acid and sul-7 amino acids.
（２） アルカリ性側で洗浄ができるので従来の無機
酸や有機酸にぶる洗浄のように洗浄時、水素ガス発生に
伴う危険性もないので安心して洗浄ができる。(2) Since cleaning can be done on the alkaline side, there is no danger of hydrogen gas generation during cleaning, unlike conventional cleaning with inorganic or organic acids, so cleaning can be carried out with peace of mind.
Claims (1)
なるｐＨ１１〜１２の混合液よりなることを特徴とする
硫酸カルシウムスケール洗浄剤。A calcium sulfate scale cleaning agent comprising a mixed solution of aminopolycarboxylic acid, a pH adjuster, and a corrosion inhibitor having a pH of 11 to 12.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14701688A JPH01316478A (en) | 1988-06-16 | 1988-06-16 | Detergent for calcium sulfate scale |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14701688A JPH01316478A (en) | 1988-06-16 | 1988-06-16 | Detergent for calcium sulfate scale |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01316478A true JPH01316478A (en) | 1989-12-21 |
Family
ID=15420637
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14701688A Pending JPH01316478A (en) | 1988-06-16 | 1988-06-16 | Detergent for calcium sulfate scale |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01316478A (en) |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6328890A (en) * | 1986-07-22 | 1988-02-06 | Mitsubishi Heavy Ind Ltd | Method for chemically cleaning scale in geothermal power plant or the like |
-
1988
- 1988-06-16 JP JP14701688A patent/JPH01316478A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6328890A (en) * | 1986-07-22 | 1988-02-06 | Mitsubishi Heavy Ind Ltd | Method for chemically cleaning scale in geothermal power plant or the like |
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