JPS5914554B2 - Cleaning agent and cleaning method for poorly soluble scale - Google Patents
Cleaning agent and cleaning method for poorly soluble scaleInfo
- Publication number
- JPS5914554B2 JPS5914554B2 JP5730576A JP5730576A JPS5914554B2 JP S5914554 B2 JPS5914554 B2 JP S5914554B2 JP 5730576 A JP5730576 A JP 5730576A JP 5730576 A JP5730576 A JP 5730576A JP S5914554 B2 JPS5914554 B2 JP S5914554B2
- Authority
- JP
- Japan
- Prior art keywords
- cleaning
- poorly soluble
- scale
- solution
- soluble scale
- 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
Links
- 238000004140 cleaning Methods 0.000 title claims description 21
- 238000000034 method Methods 0.000 title claims description 9
- 239000012459 cleaning agent Substances 0.000 title claims description 6
- 239000000243 solution Substances 0.000 claims description 11
- AEMOLEFTQBMNLQ-UHFFFAOYSA-N 3,4,5,6-tetrahydroxyoxane-2-carboxylic acid Chemical compound OC1OC(C(O)=O)C(O)C(O)C1O AEMOLEFTQBMNLQ-UHFFFAOYSA-N 0.000 claims description 9
- 239000002253 acid Substances 0.000 claims description 4
- 239000012266 salt solution Substances 0.000 claims description 2
- 239000003599 detergent Substances 0.000 claims 1
- 229910044991 metal oxide Inorganic materials 0.000 description 17
- 150000004706 metal oxides Chemical group 0.000 description 17
- CIWBSHSKHKDKBQ-JLAZNSOCSA-N Ascorbic acid Chemical compound OC[C@H](O)[C@H]1OC(=O)C(O)=C1O CIWBSHSKHKDKBQ-JLAZNSOCSA-N 0.000 description 6
- 229910052596 spinel Chemical group 0.000 description 5
- 239000011029 spinel Chemical group 0.000 description 5
- 238000012546 transfer Methods 0.000 description 5
- -1 EDTA salt Chemical class 0.000 description 4
- 229960005070 ascorbic acid Drugs 0.000 description 4
- 239000011668 ascorbic acid Substances 0.000 description 4
- 238000005253 cladding Methods 0.000 description 4
- 238000007796 conventional method Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 235000010323 ascorbic acid Nutrition 0.000 description 3
- 238000005260 corrosion Methods 0.000 description 3
- 230000007797 corrosion Effects 0.000 description 3
- 238000004090 dissolution Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N iron oxide Inorganic materials [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- 150000007524 organic acids Chemical class 0.000 description 3
- 150000003839 salts Chemical class 0.000 description 3
- KCXVZYZYPLLWCC-UHFFFAOYSA-N EDTA Chemical class OC(=O)CN(CC(O)=O)CCN(CC(O)=O)CC(O)=O KCXVZYZYPLLWCC-UHFFFAOYSA-N 0.000 description 2
- 229910017163 MnFe2O4 Inorganic materials 0.000 description 2
- BWKOZPVPARTQIV-UHFFFAOYSA-N azanium;hydron;2-hydroxypropane-1,2,3-tricarboxylate Chemical compound [NH4+].OC(=O)CC(O)(C(O)=O)CC([O-])=O BWKOZPVPARTQIV-UHFFFAOYSA-N 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- 238000001704 evaporation Methods 0.000 description 2
- 230000008020 evaporation Effects 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000005406 washing Methods 0.000 description 2
- 229910002548 FeFe Inorganic materials 0.000 description 1
- 229910015473 FeFe2O4 Inorganic materials 0.000 description 1
- QPCDCPDFJACHGM-UHFFFAOYSA-N N,N-bis{2-[bis(carboxymethyl)amino]ethyl}glycine Chemical class OC(=O)CN(CC(O)=O)CCN(CC(=O)O)CCN(CC(O)=O)CC(O)=O QPCDCPDFJACHGM-UHFFFAOYSA-N 0.000 description 1
- 229910003264 NiFe2O4 Inorganic materials 0.000 description 1
- JTPLPDIKCDKODU-UHFFFAOYSA-N acetic acid;2-(2-aminoethylamino)ethanol Chemical compound CC(O)=O.CC(O)=O.CC(O)=O.NCCNCCO JTPLPDIKCDKODU-UHFFFAOYSA-N 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000005202 decontamination Methods 0.000 description 1
- 230000003588 decontaminative effect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 238000010828 elution Methods 0.000 description 1
- 239000003112 inhibitor Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 150000002574 ketohexoses Chemical class 0.000 description 1
- 239000011259 mixed solution Substances 0.000 description 1
- NQNBVCBUOCNRFZ-UHFFFAOYSA-N nickel ferrite Chemical compound [Ni]=O.O=[Fe]O[Fe]=O NQNBVCBUOCNRFZ-UHFFFAOYSA-N 0.000 description 1
- MGFYIUFZLHCRTH-UHFFFAOYSA-N nitrilotriacetic acid Chemical class OC(=O)CN(CC(O)=O)CC(O)=O MGFYIUFZLHCRTH-UHFFFAOYSA-N 0.000 description 1
- 238000013021 overheating Methods 0.000 description 1
- XAEFZNCEHLXOMS-UHFFFAOYSA-M potassium benzoate Chemical compound [K+].[O-]C(=O)C1=CC=CC=C1 XAEFZNCEHLXOMS-UHFFFAOYSA-M 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 239000003870 refractory metal Substances 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Detergent Compositions (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
Description
【発明の詳細な説明】
本発明は、火力発電所等のボイラのスケールや原子力発
電所の一次系に付着した放射性スケール（通称クラッド
）等の難溶性スケール、すなわち、金属酸化物やスピネ
ル構造の金属酸化物等を除去する洗浄剤および洗浄方法
に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention is directed to the treatment of refractory scales such as boiler scales in thermal power plants and radioactive scales (commonly known as cladding) attached to the primary systems of nuclear power plants, that is, metal oxides and spinel structures. The present invention relates to a cleaning agent and cleaning method for removing metal oxides and the like.
一般に、火力発電所等のボイラ蒸発管のような５ 伝熱
面に付着しているスケールは熱効率や安全性の面から除
去しなければならず、また原子力発電所の一次系に付着
堆積したクラッドは放射能を低減させる目的から除去し
なければならない。これらボイラや原子力発電所の一次
系に付着している１０スケールやクラッド゛は、しばし
ば難溶性の金属酸化物やスピネル構造の金属酸化物を含
んでいる。この難溶性金属酸化物としては、Ｆｅ２Ｏ３
、Ｍ２０３等があわ、スピネル構造の金属酸化物として
は、化学式ＸＹ２０４で示される組成の結晶構１５造を
もつ、例えばＦｅＦｅ。０４・ＮｉＦｅ２０４・ＺｎＦ
ｅ２ｏ４、２ｎＭ２ｏ４等である。In general, scale adhering to heat transfer surfaces such as boiler evaporation tubes in thermal power plants must be removed from the standpoint of thermal efficiency and safety, and scale adhering to the primary system of nuclear power plants must be removed. must be removed for the purpose of reducing radioactivity. The 10 scale and cladding adhering to the primary systems of these boilers and nuclear power plants often contain hardly soluble metal oxides or metal oxides with a spinel structure. This poorly soluble metal oxide is Fe2O3
, M203, etc., and the spinel structure metal oxide is, for example, FeFe, which has a crystal structure having a composition represented by the chemical formula XY204. 04・NiFe204・ZnF
e2o4, 2nM2o4, etc.
これら難溶性の金属酸化物やスピネル構造の金属酸化物
を含むスケールやクラッドは、結晶構造が緻密なために
化学的に安定性れ’−あり、溶解除去２０は極めて困難
であつた。Scales and cladding containing these poorly soluble metal oxides and spinel-structured metal oxides are chemically unstable due to their dense crystal structures, and are extremely difficult to remove by dissolution 20.
例えば、火力発電所用ボイラの場合、洗浄後これらを含
んだスケールが火炎側に選択的に付着しているとその伝
熱面に一部残留するおそれがあわ、稼動時にその部分が
オーバーヒートされ、管の腐食増進や管の破損事故を２
５引きおこした多くの例がある。また、洗浄後原子力発
電所の一次系内にこれら難溶性クラッドが残留した場合
には除染係数が低くなつて洗浄効果が得られない。従来
かかるスケールやクラッドの洗浄には有機酸洗浄が行な
われており、洗浄効果を３０あげるために、洗浄溶液の
温度を９０〜１５０℃に上昇させ、１２〜１６時間もの
長時間あるいは数回の洗浄を行なつていたが、洗浄工程
が長くなわ洗浄操作も極めて煩雑であつた。本発明は、
上記難溶性金属酸化物やスピネル構３５造の金属酸化物
を含むスケールやクラッドを操作容易に短時間で完全に
溶解除去することを目的とするものである。For example, in the case of a boiler for a thermal power plant, if scale containing these substances selectively adheres to the flame side after cleaning, there is a risk that a portion of the scale will remain on the heat transfer surface, causing overheating of that area during operation, and Increased corrosion and pipe breakage accidents 2
5. There are many examples of this. Furthermore, if these poorly soluble cruds remain in the primary system of a nuclear power plant after cleaning, the decontamination coefficient will be low and no cleaning effect will be obtained. Conventionally, organic acid cleaning has been used to clean such scale and crud, and in order to increase the cleaning effect by 30%, the temperature of the cleaning solution is raised to 90 to 150°C, and the cleaning solution is heated for a long time of 12 to 16 hours or several times. Although the rope was washed, the washing process was long and the rope washing operation was extremely complicated. The present invention
The purpose of this method is to completely dissolve and remove scale and cladding containing the above-mentioned hardly soluble metal oxides and spinel-structured metal oxides in a short time with ease.
本発明は、アミノポリカルボン酸塩溶液とケトヘキソー
スを主成分とする洗浄剤、及びアミノポリカルボン酸塩
溶液とケトヘキソースを併用して洗浄することを特徴と
し、アミノポリカルボン酸塩としては、例えばエチレン
ジアミンテトラアセチツクァシド塩（ＥＤＴＡ塩）、ジ
エチレントリアミンペンタアセチツクアシド塩（ＤＴＰ
Ａ塩）、ニトリロトリアセチツクアシド塩（ＮＴＡ塩）
およびＮ−ヒドロキシエチルエチレンジアミントリアセ
チツクアシド塩（ＨＥＤＴＡ塩）があり、ケトヘキソー
スとしては例えばｔ−アスコルビン酸、ジヒドロ ｔ−
アスコルビン酸およびエリソルピン酸がある。The present invention is characterized by cleaning using a cleaning agent mainly containing an aminopolycarboxylate solution and a ketohexose, and a combination of an aminopolycarboxylate solution and a ketohexose. For example, ethylenediaminetetraacetic acid salt (EDTA salt), diethylenetriaminepentaacetic acid salt (DTP)
A salt), nitrilotriacetic acid salt (NTA salt)
and N-hydroxyethylethylenediamine triacetic acid salt (HEDTA salt), and ketohexoses include t-ascorbic acid, dihydro t-
There are ascorbic acid and erythorpic acid.
アミノポリカルボン酸塩の濃度は、ボイラ蒸発管の伝熱
面や原子力発電所の一次系内に付着しているスケールや
クラツド量によつて算定されるが、溶解の終点を確認し
、かつ再沈殿や再付着を防ぐために、洗浄終了時にさら
に２〜３重量％残す必要がある。したがつて、本発明で
使用するアミノポリカルボン酸塩溶液の濃度は一般に４
．０〜４０重量％が適当である。また、ケトヘキソース
の使用目的は、従来、給水中の脱酸素又は洗浄中の腐食
防止が目的であるが、本発明においては洗浄中に難溶性
金属酸化物やスピネル構造の金属酸化物の溶解促進をお
こさせるのが目的であつて、この溶解除去機構は、例え
ばアスコルビン酸においては、ＺｎＦｅ２Ｏ４＋Ｃ６Ｈ
８Ｏ６ｚｎＯ−ＦｅＯ−ＦｅＯであＶ）ＳＺｎＯ−Ｆｅ
Ｏ−ＦｅＯは化学的安定性がなく洗浄溶液に易溶性とな
り溶解除去されるものであジ、本発明で使用するケトヘ
キソースの濃度は一般に０．５〜２．０重量％が適当で
ある。The concentration of aminopolycarboxylic acid salts is calculated based on the amount of scale and crud adhering to the heat transfer surface of boiler evaporator tubes and the primary system of nuclear power plants. To prevent precipitation and re-deposition, an additional 2-3% by weight should be left at the end of the wash. Therefore, the concentration of the aminopolycarboxylic acid salt solution used in the present invention is generally 4.
．． 0 to 40% by weight is suitable. In addition, the conventional purpose of using ketohexose is to deoxidize the water supply or prevent corrosion during cleaning, but in the present invention, it promotes the dissolution of poorly soluble metal oxides and spinel-structured metal oxides during cleaning. For example, in the case of ascorbic acid, this dissolution and removal mechanism is
8O6znO-FeO-FeOV)SZnO-Fe
Since O--FeO is not chemically stable and easily soluble in a cleaning solution to be dissolved and removed, the appropriate concentration of the ketohexose used in the present invention is generally 0.5 to 2.0% by weight.
さらに本発明における洗浄に当つては、従来のように高
温にする必要はなく、温度が５０〜１００℃において難
溶性酸化物を含むスケールやクラツドを十分に溶解除去
できるものである。なお、本発明においては必要に応じ
て腐食抑制剤を加えることもできる。Further, in the cleaning according to the present invention, it is not necessary to use a high temperature as in the conventional method, and scale and crud containing poorly soluble oxides can be sufficiently dissolved and removed at a temperature of 50 to 100°C. In addition, in the present invention, a corrosion inhibitor can also be added as necessary.
このように本発明によれば、除去困難な難溶性金属酸化
物やスピネル構造の金属酸化物を含むスケールやクラツ
ドを低温度で操作容易かつ短時間で完全に溶解除去する
ことができるものである。As described above, according to the present invention, it is possible to completely dissolve and remove scales and cruds containing difficult-to-remove refractory metal oxides and spinel-structured metal oxides at low temperatures in an easy operation and in a short time. .
次に実施例を示す。実施例 １
某発電所のボイラ蒸発管の伝熱面に、火炎側２８．０ｍ
Ｔ２、炉壁側９．２′ｌ（！７流２のスケールが付着し
ているチユーブがあシ、このスケールは酸化鉄（Ｆｅ３
Ｏ４換算）で火炎側８５％、炉壁側９８％の成分組成で
あり、難溶性の金属酸化物としてＡ２Ｏ３が火炎側に３
．６％含まれていた。Next, examples will be shown. Example 1 On the heat transfer surface of a boiler evaporation tube at a certain power plant, the flame side was 28.0 m.
T2, furnace wall side 9.2'l (!7) There is a tube with scale attached to flow 2, this scale is iron oxide (Fe3
The composition is 85% on the flame side and 98% on the furnace wall side (in terms of O4), and 3% of A2O3 is on the flame side as a poorly soluble metal oxide.
．． It contained 6%.
このスケールについて従来法と本発明法による洗浄結果
は表〜１の通ｖであつた。表−１に示すように、従来の
有機酸洗浄剤であるクエン酸モノアンモンでは難溶性金
属酸化物は帯状に灰白色になつて残つており、またＥＣ
ＤＴＡアンモニウム塩のみでは１回では完全に除去でき
ず２回の洗浄でかろうじて除去されたが、本発明によれ
ば温度９０゜Ｃにおける１回洗浄で難溶性金属酸化物を
含む全スケールが容易に除去された。The results of cleaning this scale by the conventional method and the method of the present invention were as shown in Tables 1 to 1. As shown in Table 1, in the case of monoammonium citrate, which is a conventional organic acid cleaning agent, poorly soluble metal oxides remain in a grayish-white band shape, and EC
DTA ammonium salt alone could not completely remove it in one wash and was barely removed after two washes, but according to the present invention, all scales including poorly soluble metal oxides can be easily removed with one wash at a temperature of 90°C. removed.
実施例 ２スケールは表−２に示すような成分組成で、
このスケールは一部ＦｅＦｅ２Ｏ４，ＮｉＦｅ２Ｏ４，
ＭｎＦｅ２Ｏ４およびＣＯＦｅ２Ｏ４がスピネル構造を
なしている非常に難溶性の酸化物であつた。Example 2 The scale has a component composition as shown in Table 2,
This scale includes some FeFe2O4, NiFe2O4,
MnFe2O4 and COFe2O4 were very poorly soluble oxides with a spinel structure.
このスケールを従来の有機酸洗浄剤であるクエン酸モノ
アンモン溶液と、本発明によるＥＤＴＡカリウム塩、ｔ
−アスコルビン酸混合溶液との溶解力の比較をしたとこ
ろ、第１図のような結果を得た。This scale was mixed with a monoammonium citrate solution, which is a conventional organic acid cleaning agent, and an EDTA potassium salt according to the present invention, t
- When the dissolving power was compared with that of an ascorbic acid mixed solution, the results shown in Figure 1 were obtained.
なお、この比較試験の条件は表−３の通りであつた。実
施例 ３
某発電所のボイラ蒸発管の伝熱面に付着していたスケー
ルは表−４に示すような成分組成であつたｏこのスケー
ルは、Ｆｅ３Ｏ４の一部およびＺｎＯ，ＭｎＯがＺｎＦ
ｅ２Ｏ４，ＭｎＦｅ２Ｏ４のスピネル構造酸化物となつ
ている非常に難溶性のもので、このスケールについて従
来法と本発明法による洗浄結果は表−５の通りであつた
。The conditions for this comparative test were as shown in Table 3. Example 3 The scale attached to the heat transfer surface of a boiler evaporator tube at a certain power plant had a composition as shown in Table 4.
The scale is a spinel structure oxide of e2O4 and MnFe2O4, and is very poorly soluble.Table 5 shows the cleaning results for this scale using the conventional method and the method of the present invention.
図面は本発明法と従来法との鉄イオンの溶出効果を示す
線図である。The drawing is a diagram showing the elution effect of iron ions between the method of the present invention and the conventional method.
Claims (1)
成分とする難溶性スケールの洗浄剤。 ２ 前記アミノポリカルボン酸塩溶液とケトヘキソース
の濃度を、それぞれ４．０〜４０重量％、０．５〜２．
０重量％とした特許請求の範囲第１項記載の難溶性スケ
ールの洗浄剤。 ３ アミノポリカルボン酸塩溶液とケトヘキソースを併
用して洗浄することを特徴とする難溶性スケールの洗浄
方法。 ４ 前記アミノポリカルボン酸塩溶液とケトヘキソース
の濃度を、それぞれ４．０〜４０重量％、０．５〜２．
０重量％とした特許請求の範囲第３項記載の難溶性スケ
ールの洗浄方法。 ５ 前記アミノポリカルボン酸塩溶液とケトヘキソース
との洗浄溶液の温度を５０〜１００℃として洗浄する特
許請求の範囲第３項又は第４項記載の難溶性スケールの
洗浄方法。[Scope of Claims] 1. A cleaning agent for poorly soluble scale containing an aminopolycarboxylic acid salt solution and ketohexose as main components. 2. The concentrations of the aminopolycarboxylate solution and ketohexose are 4.0 to 40% by weight and 0.5 to 2.0% by weight, respectively.
The detergent for sparsely soluble scale according to claim 1, wherein the content is 0% by weight. 3. A method for cleaning poorly soluble scale, characterized by cleaning using a combination of an aminopolycarboxylate solution and a ketohexose. 4. The concentrations of the aminopolycarboxylate solution and ketohexose are 4.0 to 40% by weight and 0.5 to 2.0% by weight, respectively.
The method for cleaning poorly soluble scale according to claim 3, wherein the content is 0% by weight. 5. The method of cleaning poorly soluble scale according to claim 3 or 4, wherein the temperature of the cleaning solution of the aminopolycarboxylate solution and ketohexose is set at 50 to 100°C.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5730576A JPS5914554B2 (en) | 1976-05-20 | 1976-05-20 | Cleaning agent and cleaning method for poorly soluble scale |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5730576A JPS5914554B2 (en) | 1976-05-20 | 1976-05-20 | Cleaning agent and cleaning method for poorly soluble scale |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS52140508A JPS52140508A (en) | 1977-11-24 |
| JPS5914554B2 true JPS5914554B2 (en) | 1984-04-05 |
Family
ID=13051833
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5730576A Expired JPS5914554B2 (en) | 1976-05-20 | 1976-05-20 | Cleaning agent and cleaning method for poorly soluble scale |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5914554B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5813879B2 (en) * | 1979-02-20 | 1983-03-16 | 日立造船株式会社 | Cask decontamination method |
-
1976
- 1976-05-20 JP JP5730576A patent/JPS5914554B2/en not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS52140508A (en) | 1977-11-24 |
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