JPH01316476A - Detergent for calcium sulfate scale - Google Patents
Detergent for calcium sulfate scaleInfo
- Publication number
- JPH01316476A JPH01316476A JP14701388A JP14701388A JPH01316476A JP H01316476 A JPH01316476 A JP H01316476A JP 14701388 A JP14701388 A JP 14701388A JP 14701388 A JP14701388 A JP 14701388A JP H01316476 A JPH01316476 A JP H01316476A
- Authority
- JP
- Japan
- Prior art keywords
- calcium sulfate
- scale
- detergent
- acid
- corrosion inhibitor
- 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 55
- 239000003599 detergent Substances 0.000 title abstract 5
- 239000002253 acid Substances 0.000 claims abstract description 17
- 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
- BVKZGUZCCUSVTD-UHFFFAOYSA-M Bicarbonate Chemical compound OC([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-M 0.000 claims abstract description 9
- 239000003002 pH adjusting agent Substances 0.000 claims abstract description 6
- 239000012459 cleaning agent Substances 0.000 claims description 8
- 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
- UIIMBOGNXHQVGW-UHFFFAOYSA-M Sodium bicarbonate Chemical compound [Na+].OC([O-])=O UIIMBOGNXHQVGW-UHFFFAOYSA-M 0.000 abstract description 6
- 239000003513 alkali Substances 0.000 abstract description 6
- 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 3
- 239000011736 potassium bicarbonate Substances 0.000 abstract description 3
- 229910000028 potassium bicarbonate Inorganic materials 0.000 abstract description 3
- 235000015497 potassium bicarbonate Nutrition 0.000 abstract description 3
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 abstract description 3
- 229910000030 sodium bicarbonate Inorganic materials 0.000 abstract description 3
- 235000017557 sodium bicarbonate Nutrition 0.000 abstract description 3
- 239000000126 substance Substances 0.000 abstract description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical class OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 abstract description 2
- 238000010438 heat treatment Methods 0.000 abstract description 2
- 239000004094 surface-active agent Substances 0.000 abstract description 2
- 150000001732 carboxylic acid derivatives Chemical class 0.000 abstract 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 abstract 1
- 230000001105 regulatory effect Effects 0.000 abstract 1
- 235000011132 calcium sulphate Nutrition 0.000 description 22
- 238000004140 cleaning Methods 0.000 description 15
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 10
- 239000013535 sea water Substances 0.000 description 7
- VEXZGXHMUGYJMC-UHFFFAOYSA-N Hydrochloric acid Chemical compound Cl VEXZGXHMUGYJMC-UHFFFAOYSA-N 0.000 description 6
- BDAGIHXWWSANSR-UHFFFAOYSA-N methanoic acid Natural products OC=O BDAGIHXWWSANSR-UHFFFAOYSA-N 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- 238000004090 dissolution Methods 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
- 238000010612 desalination reaction Methods 0.000 description 4
- 150000007524 organic acids Chemical class 0.000 description 4
- 235000005985 organic acids Nutrition 0.000 description 4
- 238000001556 precipitation Methods 0.000 description 4
- 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 3
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 3
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- 239000011575 calcium Substances 0.000 description 3
- 229910052791 calcium Inorganic materials 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 235000019253 formic acid Nutrition 0.000 description 3
- 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 3
- ATRRKUHOCOJYRX-UHFFFAOYSA-N Ammonium bicarbonate Chemical compound [NH4+].OC([O-])=O ATRRKUHOCOJYRX-UHFFFAOYSA-N 0.000 description 2
- 229910019440 Mg(OH) Inorganic materials 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 239000001099 ammonium carbonate Substances 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
- 238000001816 cooling Methods 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- NWZSZGALRFJKBT-KNIFDHDWSA-N (2s)-2,6-diaminohexanoic acid;(2s)-2-hydroxybutanedioic acid Chemical compound OC(=O)[C@@H](O)CC(O)=O.NCCCC[C@H](N)C(O)=O NWZSZGALRFJKBT-KNIFDHDWSA-N 0.000 description 1
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 1
- 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
- 229910000013 Ammonium bicarbonate Inorganic materials 0.000 description 1
- VHUUQVKOLVNVRT-UHFFFAOYSA-N Ammonium hydroxide Chemical compound [NH4+].[OH-] VHUUQVKOLVNVRT-UHFFFAOYSA-N 0.000 description 1
- QZKRHPLGUJDVAR-UHFFFAOYSA-K EDTA trisodium salt Chemical compound [Na+].[Na+].[Na+].OC(=O)CN(CC([O-])=O)CCN(CC([O-])=O)CC([O-])=O QZKRHPLGUJDVAR-UHFFFAOYSA-K 0.000 description 1
- PIICEJLVQHRZGT-UHFFFAOYSA-N Ethylenediamine Chemical compound NCCN PIICEJLVQHRZGT-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 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 1
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 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
- 150000001412 amines Chemical class 0.000 description 1
- 235000012538 ammonium bicarbonate Nutrition 0.000 description 1
- 235000012501 ammonium carbonate Nutrition 0.000 description 1
- 239000000908 ammonium hydroxide Substances 0.000 description 1
- 150000001450 anions Chemical class 0.000 description 1
- 239000011324 bead Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000013522 chelant Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000000668 effect on calcium Effects 0.000 description 1
- 230000008020 evaporation Effects 0.000 description 1
- -1 for example Chemical compound 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- IKDUDTNKRLTJSI-UHFFFAOYSA-N hydrazine monohydrate Substances O.NN IKDUDTNKRLTJSI-UHFFFAOYSA-N 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 235000015243 ice cream Nutrition 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000012528 membrane Substances 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- 238000010979 pH adjustment Methods 0.000 description 1
- 229960003330 pentetic acid Drugs 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 229940086066 potassium hydrogencarbonate Drugs 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000004445 quantitative analysis Methods 0.000 description 1
- 238000005245 sintering Methods 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- ILJSQTXMGCGYMG-UHFFFAOYSA-N triacetic acid Chemical compound CC(=O)CC(=O)CC(O)=O ILJSQTXMGCGYMG-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 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
- C23G1/24—Cleaning or pickling metallic material with solutions or molten salts with neutral 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０ａＯＯ，。 The scale that precipitates and adheres to the heat transfer surface is 0aOO.
Ｍｇ（ＯＨ）を等のアルカリスケールは塩酸、硫酸等の
無機酸あるいは蟻酸、スルファミノ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ような複雑な方法でおった
。Alkaline scales such as Mg(OH) can be dissolved and removed using inorganic acids such as hydrochloric acid and sulfuric acid, or organic acids such as formic acid and sulfamic acid, but removal of hard scales whose main component is calcium sulfate is particularly complicated as follows. It was done in a special way.
硫酸カルシウムを第１式に示すように高温の高アルカリ
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式に示すように無機酸と反応させて溶解する。Calcium sulfate is converted into calcium carbonate and calcium hydroxide using a high temperature and highly alkali as shown in the first equation, and then reacted with an inorganic acid and dissolved as shown in the second equation.
０ａＯＯ，＋０ａ（ＯＨ）！＋２１ＪａｔＳｏ、 −
−−第１弐〇ａＯＯ１＋ Ｏａ （ＯＲ）！ ＋ ４Ｈ
ＯＬ −一２０ａ０４ ＋ ３ＨｔＯ＋ Ｃｏｔ↑
・・・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シ返さない
と完全な溶解はできなかった。0aOO, +0a(OH)! +21 JatSo, -
--1st 2〇aOO1+ Oa (OR)! +4H
OL -120a04 + 3HtO+ Cot↑
... Equation 2 However, in the reaction of Equation 1, 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 could not be achieved unless this was repeated many times.
海水淡水化の方法は蒸発法、冷凍法、膜法なと数多く開
発されているが、現在量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、付着によシ伝熱を阻
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。Many methods have been developed for seawater desalination, including evaporation, freezing, and membrane methods, but the one that is currently being put into practical use is the evaporation method. A fatal problem with evaporative seawater desalination equipment is that scale precipitation and adhesion on heat transfer surfaces can obstruct heat transfer, reduce the thermal efficiency of the equipment, and even cause plant operation to stop. It will be done.
伝熱を阻害するスケールにはアルカリスケール［０ａＯ
Ｏ，、Ｍｇ（ＯＨ）１ ］と硫酸カルシウム（０ａ８０
．−２１１１１０ 、 Ｃａ８０．−１４Ｈ，Ｏ、０
ａ８０． ）であるが、アルカリスケールの析出防止に
ついては酸を海水に添加して脱炭酸するｐＨコントロー
ル技術が確立され、すでに実用化されているので問題は
なくなった。Alkaline scale [0aO
O,, Mg(OH)1 ] and calcium sulfate (0a80
．． -211110, Ca80. -14H,O,0
a80. ) However, to prevent the precipitation of alkaline scale, the problem has disappeared because a pH control technology in which acid is added to seawater to decarboxylate it has been established and is already in practical use.
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
よって除去するか、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, even among calcium sulfates, anhydrous salts tend to precipitate on heat transfer surfaces, and unlike alkali scales, there is no fundamental method for preventing precipitation, so heat transfer may occur due to the precipitation and adhesion of scales whose main component is calcium sulfate. If this occurs, it is necessary to remove it by physical methods or, if the adhesion is severe, to replace the heat transfer part.
本発明はかかる現状にＳ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を提供しようと
するものである。The present invention takes account of the current situation and provides a chemical cleaning agent that can completely and efficiently dissolve and remove scale on heat transfer surfaces.
〔課題を解決するだめの手段］
本発明はアミノポリカルボン酸、ｐＨ１４ｍ剤及び腐食
抑制剤よりなるｐＨ７〜９０溶液に炭酸水素塩をｔ５〜
２重量係添加してなることを特徴とする硫酸カルシウム
スケールの洗浄剤である。[Means for Solving the Problems] The present invention involves adding hydrogen carbonate to a pH 7-90 solution consisting of an aminopolycarboxylic acid, a pH 14m agent, and a corrosion inhibitor from t5 to
This is a calcium sulfate scale cleaning agent characterized by adding 2 parts by weight.
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
ジアミン西酢酸（以下、ＥＤＴムと略す）、二）！７０
三酢酸（以下、ＢＩＴムと略す）。The aminopolycarboxylic acid in the present invention is ethylene diamine acetic acid (hereinafter abbreviated as EDT), 2)! 70
Triacetic acid (hereinafter abbreviated as BIT).
ヒドロキシエチルエチレンジアミン三酢酸（以下、Ｈ］
ｌ［ｉＤＴムと略す）、ジエチレントリアミン五酢酸（
以下、ＤＴＰムと略す）、トリエチレンテトラミン六酢
酸（以下、ＴＴ）ｉムと略す）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種以上がスラリー
として使用される。Hydroxyethylethylenediaminetriacetic acid (hereinafter referred to as H)
l [abbreviated as iDT], diethylenetriaminepentaacetic acid (
Examples include DTP (hereinafter abbreviated as DTP), triethylenetetraminehexaacetic acid (hereinafter abbreviated as TT), and at least one of these aminopolycarboxylic acids is used as a slurry.
ｐＨ調整剤としては、上記スラリーのＰＨを７〜９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、列をあげれば、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、水酸化アンモニウム、水化ヒド
ラジンなどがある。As the pH adjuster, any alkaline agent that can adjust the pH of the slurry to 7 to 9 can be used, examples include sodium hydroxide, potassium hydroxide, monoethanolamine, jetanolamine,
These include triethanolamine, ammonium hydroxide, and hydrazine hydrate.
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ン誘導体及び界
面活性剤よシなるヒビロンに−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, Hibilon-4 and Hibilon-400 manufactured by Sugimura Chemical Industry Co., Ltd., whose main components are amine derivatives and surfactants.
and -420 can be used for Hibilon. .
また、炭酸水素塩としては、例えば炭酸水素ナトリウム
、炭酸水素カリウム、炭酸水素アンモニウムなどが使用
でき、これらの一種以上をｔ５〜２重量係添加して使用
する。Further, as the hydrogen carbonate, for example, sodium hydrogen carbonate, potassium hydrogen carbonate, ammonium hydrogen carbonate, etc. can be used, and one or more of these are added in a weight ratio of t5 to 2.
本発明の洗浄剤は、液温度７０〜９５℃の範囲で使用す
ることによシ、硫酸カルシウムを主成分とする硬質スケ
ールに対し非常にすぐれた溶解力がある。The cleaning agent of the present invention, when used at a liquid temperature in the range of 70 to 95° C., has an extremely excellent ability to dissolve hard scale mainly composed of calcium sulfate.
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、付着して熱効
率が低下しはじめたら装置を一時停止して、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
がら洗浄液温度を７０〜９５℃に保持して伝熱面に析出
。In addition, regarding the timing and method of cleaning, if scale begins to precipitate or adhere to the heat transfer surfaces of the seawater desalination equipment and seawater cooling equipment and the thermal efficiency begins to decrease, the equipment should be temporarily stopped and the cleaning solution should be injected into the cleaning parts. Inject it with a pump and keep the temperature of the cleaning solution at 70 to 95°C while circulating it with a circulation pump to deposit it on the heat transfer surface.
付着した硫酸カルシウムを主成分とする硬質スケールを
溶解除去するようにすればよい。What is necessary is to dissolve and remove the attached hard scale mainly composed of calcium sulfate.
本発明洗浄剤による７硫酸カルシウムスケールの溶解力
及び溶解量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、付着した硫酸カルシ
ウムのスケール量によって決定されるが、効果的な洗浄
を達成するためには５〜１５重量係の濃度が好ましい。The dissolving power and amount of calcium sulfate scale dissolved by the cleaning agent of the present invention depend on the aminopolycarboxylic acid concentration, so the concentration is determined by the amount of calcium sulfate scale precipitated and attached to the object to be cleaned. In order to achieve thorough cleaning, a concentration of 5 to 15 parts by weight is preferred.
ｐＨ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
れらアルカリ剤をアミノポリカルボン酸に併用添加する
ことによジ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。Alkaline agents used as pH adjusters themselves have no dissolving effect on calcium sulfate scale, but by adding these alkaline agents to aminopolycarboxylic acid, the solubility of diaminopolycarboxylic acid in water can be increased. It plays a major role as an indirect dissolution aid for calcium sulfate scale.
ま九炭酸水素ナトリウム、炭酸水素カリウム。Sodium bicarbonate, potassium bicarbonate.
炭酸氷菓アンモニウム等の炭酸水素塩そのものも上記の
アルカリ剤と同様、直接的には硫酸カルシウムスケール
に対して溶解力はないがアミノポリカルボン酸に上記ア
ルカリ剤と併用添加することによシ、硫酸カルシウムス
ケールの溶解力に最適なｐＨ範囲（７〜９）が保持する
作用を果す。炭酸水素塩の添加量は１５重量優以上が好
ましく、それ以下の濃度では最適ｐＨ保持が困難となシ
λ重量僑以上に上げても、その変化は特にないので経済
性を考慮して上限を２重量係とした。Similar to the above-mentioned alkali agents, hydrogen carbonates such as ammonium carbonate ice cream do not have the ability to directly dissolve calcium sulfate scale, but when added to aminopolycarboxylic acids in combination with the above-mentioned alkali agents, sulfuric acid The optimum pH range (7 to 9) for the ability to dissolve calcium scale serves to maintain it. The amount of hydrogen carbonate added is preferably 15% by weight or more; if the concentration is less than that, it will be difficult to maintain the optimum pH, and even if the concentration is increased to more than λ, there will be no particular change, so the upper limit should be set in consideration of economic efficiency. There were 2 weight staff.
もし、炭酸水素塩を全く併用添加せずに上記アルカリ剤
のみでｐＨを７〜９に調整して洗浄したとした場合、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ポリカルボン
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ｐＨが低下することによυ、ｐＨ５以下まで下がる
ので硫酸カルシウムの溶解はそれ以後殆んど進まなくな
る。If cleaning is performed by adjusting the pH to 7 to 9 only with the above alkaline agent without adding any hydrogen carbonate, calcium sulfate will be eluted by the aminopolycarboxylic acid in the cleaning agent of the present invention. Since calcium and aminopolycarboxylic acid form a strong soluble complex salt, sulfuric acid is liberated and the pH is lowered to below 5, so that dissolution of calcium sulfate hardly progresses after that.
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
ときの効果的洗浄温度は高温になるほど大きいが、実用
上７０〜９５℃の範囲内で十分である。The effective cleaning temperature for dissolving and removing scale mainly composed of calcium sulfate increases as the temperature increases, but a range of 70 to 95°C is practically sufficient.
また本発明の洗浄剤には、腐食抑制剤？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１３％程
度で十分である。Also, does the cleaning agent of the present invention contain a corrosion inhibitor? Although it is necessary to add the corrosion inhibitor, any known corrosion inhibitor can be appropriately selected and used as described above, as long as it has a corrosion inhibiting effect on steel materials. A concentration of about 13% is sufficient.
本発明において使用するアミノポリカルボン酸とｐＨ調
整のためのアルカリ剤とｐＨ保持剤のための炭酸水素塩
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ＭＤＴＡを、ｐＨ調整剤とし
て水酸化ナトリウムを、ｐＨ保持剤のために炭酸水素塩
として炭酸水素ナトリウムを例にとって説明すると、ｐ
Ｈ！ ７〜９０範囲において、ＭＤＴＡのカルシウム
に対するキレート形成は下記第１式に示すように作用し
、カルシウムの硫酸塩スケールを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, an alkaline agent for pH adjustment, and a hydrogen carbonate mixture for pH maintenance agent is as follows: To explain sodium hydroxide as an example of sodium bicarbonate as a pH-maintaining agent, p
H! It is believed that in the range of 7 to 90, the chelate formation of MDTA with respect to calcium acts as shown in the following formula 1, and effectively dissolves the calcium sulfate scale.
なお炭酸水素塩を添加することによシ、ｐＨが低下せず
好適ｐｌｉ範曲を保持するのは第３式に示すように馬ａ
Ｏ，はｐＨ７〜９０範囲内では殆んど存在することな（
Ｈ，ＣｊＯ，→Ｅ、Ｏ＋ Ｃｏ、↑に分解するためであ
る。It should be noted that by adding hydrogen carbonate, the pH does not decrease and a suitable pli range is maintained, as shown in the third equation.
O, is hardly present in the pH range of 7 to 90 (
This is because it decomposes into H, CjO, → E, O+ Co, ↑.
Ｏａ日０４＋ ＮａＨＯＯ，＋ Ｎａ、ＢＹ →Ｎａ
、ＯａＹ”＋Ｎａ、ＥＩＯ，＋Ｈ，Ｃｏ、 −−−第
３式％式％
ただしＮａ、ＨＹ ：エチレンジアミン四酢酸の三ナト
リウム塩（ｐＨ７〜９）
Ｙ ：エチレンジアミン四酢酸の陰イ
オン
〔実施列〕
第１表に本発明の一実施例である試験結果を示す。Oaday 04+ NaHOO, + Na, BY →Na
, OaY"+Na, EIO, +H, Co, --- Third formula % formula % However, Na, HY: trisodium salt of ethylenediaminetetraacetic acid (pH 7-9) Y: anion of ethylenediaminetetraacetic acid [practical column] Table 1 shows test results as an example of the present invention.
第１表に示した組成の洗浄液１００Ｍｔ’１２００−の
ビー力にとシ、これに無水硫酸カルシウムｚ２５１の錠
剤（市販の無水硫酸カルシウム粉末２．２５５’をφ２
０Ｘｔ３＋ａの成型器に入れて油圧機で１００ ｋｇ／
ｃＩｎ” ｔで加圧成型後、９００℃の電気炉で焼結し
たもの）１〜３錠を入れ、加熱板付きスタラー上に置い
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
よシ、定量分析を行ってその溶解率を求めた。A cleaning solution of the composition shown in Table 1 was applied to the cleaning solution with a bead force of 100 Mt'1200 mm.
Put it in a 0Xt3+a molding machine and use a hydraulic machine to make it 100 kg/
Place 1 to 3 tablets (1 to 3 tablets (after pressure molding in cIn"t) and sintering in an electric furnace at 900°C, place on a stirrer with a heating plate, and maintain the specified temperature while stirring the cleaning liquid with a rotor. The time required for the calcium sulfate tablets to completely dissolve was determined.For those that did not completely dissolve, quantitative analysis was performed using an atomic absorption spectrophotometer to determine the dissolution rate.
また比較のため第２表に示す塩酸、硫酸等の無機酸及び
蟻酸、スルファミン酸等の有機酸による洗浄効果につい
ても行った。For comparison, 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 examined.
本発明によシ次のような効果を萎する。 The present invention eliminates the following effects.
（１１アミノポリカルボン酸にｐＨ調整剤を添加してｐ
Ｈ’ｉ７〜９０範囲内に調整した溶液に、さらに炭酸水
素塩を１．５〜２％併用添加してなる混合液で洗浄する
ことによシ、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
。(By adding a pH adjuster to 11-aminopolycarboxylic acid, p
The dissolution of aminopolycarboxylic acid into calcium sulfate scale can be achieved by washing with a mixed solution prepared by adding 1.5 to 2% hydrogen carbonate to a solution adjusted to an H'i of 7 to 90. Conventional hydrochloric acid because it works effectively.
硫酸等の無機酸洗浄や蟻酸、スルファミン酸等の有機酸
洗浄にくらべ、はるかに効率よく洗浄ができる。Compared to cleaning with inorganic acids such as sulfuric acid and organic acids such as formic acid and sulfamic acid, this method can clean much more efficiently.
（２） アルカリ性側で洗浄ができるので、従来の無
機酸や有機酸による洗浄のように洗浄時、水素ガス発生
に伴う危険性もなく洗浄ができる。(2) Since cleaning can be performed on the alkaline side, there is no danger associated with hydrogen gas generation during cleaning, unlike conventional cleaning with inorganic acids or organic acids.
Claims (1)
なるｐＨ７〜９０溶液に炭酸水素塩を１．５〜２重量％
添加してなることを特徴とする硫酸カルシウムスケール
の洗浄剤。1.5-2% by weight of bicarbonate in a pH 7-90 solution consisting of aminopolycarboxylic acid, pH adjuster and corrosion inhibitor.
A cleaning agent for calcium sulfate scale, characterized by the addition of calcium sulfate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14701388A JPH01316476A (en) | 1988-06-16 | 1988-06-16 | Detergent for calcium sulfate scale |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14701388A JPH01316476A (en) | 1988-06-16 | 1988-06-16 | Detergent for calcium sulfate scale |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01316476A true JPH01316476A (en) | 1989-12-21 |
Family
ID=15420574
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14701388A Pending JPH01316476A (en) | 1988-06-16 | 1988-06-16 | Detergent for calcium sulfate scale |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01316476A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6761774B2 (en) * | 2001-05-24 | 2004-07-13 | Basf Corporation | Composition and method for the in situ removal scale from a substrate |
| JP2009125680A (en) * | 2007-11-26 | 2009-06-11 | Mitsubishi Materials Corp | Steam well descaling method in geothermal power generation facilities |
| CN114045188A (en) * | 2021-11-29 | 2022-02-15 | 胡翠华 | Neutral environment-friendly cleaning agent and preparation method and application thereof |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5652115A (en) * | 1979-10-04 | 1981-05-11 | Sumitomo Metal Ind Ltd | Surface cutting of steel plate and device therefor |
| 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 JP14701388A patent/JPH01316476A/en active Pending
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5652115A (en) * | 1979-10-04 | 1981-05-11 | Sumitomo Metal Ind Ltd | Surface cutting of steel plate and device therefor |
| JPS6328890A (en) * | 1986-07-22 | 1988-02-06 | Mitsubishi Heavy Ind Ltd | Method for chemically cleaning scale in geothermal power plant or the like |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6761774B2 (en) * | 2001-05-24 | 2004-07-13 | Basf Corporation | Composition and method for the in situ removal scale from a substrate |
| JP2009125680A (en) * | 2007-11-26 | 2009-06-11 | Mitsubishi Materials Corp | Steam well descaling method in geothermal power generation facilities |
| CN114045188A (en) * | 2021-11-29 | 2022-02-15 | 胡翠华 | Neutral environment-friendly cleaning agent and preparation method and application thereof |
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