JPS6222680B2 - - Google Patents
Info
- Publication number
- JPS6222680B2 JPS6222680B2 JP13892782A JP13892782A JPS6222680B2 JP S6222680 B2 JPS6222680 B2 JP S6222680B2 JP 13892782 A JP13892782 A JP 13892782A JP 13892782 A JP13892782 A JP 13892782A JP S6222680 B2 JPS6222680 B2 JP S6222680B2
- Authority
- JP
- Japan
- Prior art keywords
- water
- dissolved oxygen
- scale
- cleaning
- ppb
- 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
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 93
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 46
- 239000001301 oxygen Substances 0.000 claims description 46
- 229910052760 oxygen Inorganic materials 0.000 claims description 46
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 42
- 238000000034 method Methods 0.000 claims description 23
- 239000000377 silicon dioxide Substances 0.000 claims description 21
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 4
- MHAJPDPJQMAIIY-UHFFFAOYSA-N Hydrogen peroxide Chemical compound OO MHAJPDPJQMAIIY-UHFFFAOYSA-N 0.000 claims description 4
- 229910001882 dioxygen Inorganic materials 0.000 claims description 4
- 239000012498 ultrapure water Substances 0.000 claims description 3
- 239000003570 air Substances 0.000 claims 1
- 238000004140 cleaning Methods 0.000 description 39
- NWUYHJFMYQTDRP-UHFFFAOYSA-N 1,2-bis(ethenyl)benzene;1-ethenyl-2-ethylbenzene;styrene Chemical compound C=CC1=CC=CC=C1.CCC1=CC=CC=C1C=C.C=CC1=CC=CC=C1C=C NWUYHJFMYQTDRP-UHFFFAOYSA-N 0.000 description 11
- 238000011282 treatment Methods 0.000 description 10
- 239000003456 ion exchange resin Substances 0.000 description 9
- 229920003303 ion-exchange polymer Polymers 0.000 description 9
- 239000003957 anion exchange resin Substances 0.000 description 8
- 239000000126 substance Substances 0.000 description 8
- 239000003729 cation exchange resin Substances 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 6
- 230000002378 acidificating effect Effects 0.000 description 5
- 238000005260 corrosion Methods 0.000 description 5
- 230000007797 corrosion Effects 0.000 description 5
- 239000007788 liquid Substances 0.000 description 5
- OAKJQQAXSVQMHS-UHFFFAOYSA-N Hydrazine Chemical compound NN OAKJQQAXSVQMHS-UHFFFAOYSA-N 0.000 description 4
- 239000002253 acid Substances 0.000 description 4
- 238000010612 desalination reaction Methods 0.000 description 4
- 239000012535 impurity Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000000746 purification Methods 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- 238000010521 absorption reaction Methods 0.000 description 3
- 238000006114 decarboxylation reaction Methods 0.000 description 3
- 238000007872 degassing Methods 0.000 description 3
- 238000010828 elution Methods 0.000 description 3
- 229920006395 saturated elastomer Polymers 0.000 description 3
- 239000000725 suspension Substances 0.000 description 3
- 229940123973 Oxygen scavenger Drugs 0.000 description 2
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 2
- 150000007513 acids Chemical class 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 229940023913 cation exchange resins Drugs 0.000 description 2
- 239000004568 cement Substances 0.000 description 2
- 239000012459 cleaning agent Substances 0.000 description 2
- 238000011033 desalting Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000008236 heating water Substances 0.000 description 2
- 239000008235 industrial water Substances 0.000 description 2
- 238000007689 inspection Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000006386 neutralization reaction Methods 0.000 description 2
- 230000000737 periodic effect Effects 0.000 description 2
- 238000010248 power generation Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- QJZYHAIUNVAGQP-UHFFFAOYSA-N 3-nitrobicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic acid Chemical compound C1C2C=CC1C(C(=O)O)C2(C(O)=O)[N+]([O-])=O QJZYHAIUNVAGQP-UHFFFAOYSA-N 0.000 description 1
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical compound OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- 229920001732 Lignosulfonate Polymers 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000000292 calcium oxide Substances 0.000 description 1
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 1
- 238000004040 coloring Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000007599 discharging Methods 0.000 description 1
- 239000003344 environmental pollutant Substances 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 239000008214 highly purified water Substances 0.000 description 1
- 239000004021 humic acid Substances 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 229920005610 lignin Polymers 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000005416 organic matter Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 239000002244 precipitate Substances 0.000 description 1
- 238000001556 precipitation Methods 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 230000002285 radioactive effect Effects 0.000 description 1
- 239000012857 radioactive material Substances 0.000 description 1
- 239000002901 radioactive waste Substances 0.000 description 1
- 230000003134 recirculating effect Effects 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000007711 solidification Methods 0.000 description 1
- 230000008023 solidification Effects 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000002351 wastewater Substances 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)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
Description
【発明の詳細な説明】
この発明はボイラプラント、原子力プラントな
どの加熱水系の機器配管類内表面に析出、付着、
堆積したシリカまたは有機物スケールを除去する
方法に関するものである。DETAILED DESCRIPTION OF THE INVENTION The present invention aims to prevent precipitation, adhesion, and
The present invention relates to a method for removing deposited silica or organic scale.
発電用の貫流型または循環型ボイラプラント、
あるいは沸騰水型または加圧水型原子力プラント
などの加熱水系、特に50Kgｆ／cm2以上の圧力で運
転される加熱水系においては、高純度の給水を供
給し、腐食およびスケールの発生を防止してい
る。一般にこの種の加熱水系における給水は、工
業用水などの原水を、イオン交換樹脂を含む脱塩
装置により脱塩し、真空もしくは加熱式脱気装置
を用いた物理的脱気方法および（または）ヒドラ
ジンもしくは亜硫酸塩を用いた化学的脱酸素方法
により脱気、脱酸素し、ほとんど不純物を含まな
い状態で給水される。 once-through or circulation boiler plants for power generation;
Alternatively, in heated water systems such as boiling water type or pressurized water type nuclear power plants, especially heated water systems operated at pressures of 50 Kgf/cm 2 or higher, highly purified water is supplied to prevent corrosion and scale formation. In general, the water supply in this type of heated water system is obtained by desalinating raw water such as industrial water using a desalination device containing an ion exchange resin, and then using a physical degassing method using a vacuum or heating degassing device and/or by using hydrazine. Alternatively, the water is degassed and deoxidized by a chemical deoxidation method using sulfite, and the water is supplied in a state containing almost no impurities.
ところが、このような高純度の給水でも、原水
の採取場所によつてはシリカやフミン酸、リグニ
ンスルホン酸等の有機物が微量に混入し、これら
が長期の運転中に加熱水系の金属表面に析出、付
着、堆積してスケールを生成し、種々の障害の原
因となる。 However, even with such high-purity water supply, depending on where the raw water is collected, trace amounts of organic substances such as silica, humic acid, and lignin sulfonic acid may be mixed in, and these may precipitate on the metal surface of the heated water system during long-term operation. , adheres and accumulates to form scale, which causes various problems.
従来、これらのスケールはボイラまたは原子力
プラントの定期点検のために運転が停止された
際、酸、アルカリなどの洗浄剤により化学的に除
去されていた。このような化学的洗浄方法におい
ては、洗浄のための複雑な作業が必要であるとと
もに、大量の廃液が発生し、中和等による困難な
処理が必要となつた。特に原子力プラントの場
合、放射性物質を含むため、被曝を避けての中
和、蒸発法等による濃縮後のセメント等による固
化などの特殊な処理を必要としていた。また残留
する洗浄剤に基づく腐食あるいは汚染などのいわ
ゆるアフターフエイント現象が発生するなどの問
題点があつた。 Conventionally, these scales have been chemically removed using cleaning agents such as acids and alkalis when the boiler or nuclear power plant is shut down for periodic inspection. Such chemical cleaning methods require complicated cleaning operations and generate a large amount of waste liquid, which requires difficult treatments such as neutralization. Particularly in the case of nuclear power plants, because they contain radioactive materials, special treatment is required to avoid exposure, such as neutralization, concentration using evaporation methods, and solidification with cement. Further, there are problems such as so-called afterfaint phenomena such as corrosion or contamination caused by residual cleaning agents.
この発明は、このような従来法における問題点
を改善するためのもので、単に高温条件下で溶存
酸素を10ppb以上含む脱塩水と接触させるという
簡単な作業で安全かつ効率的にシリカまたは有機
物スケールを除去することのできるスケールの除
去方法を提供することを目的としている。 This invention aims to improve the problems in conventional methods. Silica or organic scale can be removed safely and efficiently by simply contacting the water with demineralized water containing 10 ppb or more of dissolved oxygen under high temperature conditions. The purpose of the present invention is to provide a scale removal method that can remove scale.
この発明は溶存酸素が7ppb以下の高純度水が
供給される加熱水系の内壁面に生成したシリカま
たは有機物スケールに、溶存酸素を10ppb以上含
む脱塩水を、80℃以上の状態で接触させることを
特徴とするスケールの除去方法である。 This invention involves bringing demineralized water containing 10 ppb or more of dissolved oxygen into contact with silica or organic scale formed on the inner wall surface of a heated water system that is supplied with high-purity water with dissolved oxygen of 7 ppb or less at a temperature of 80°C or higher. This is a distinctive scale removal method.
本発明で加熱水系とは、系内の水（水蒸気を含
む）が加熱される密閉または開放系の水系であ
る。 In the present invention, a heated water system is a closed or open water system in which water (including steam) is heated.
発電用に多く使用される貫流型または循還型ボ
イラプラントあるいは沸騰水型または加圧水型原
子力プラントなど、50Kgｆ／cm2以上の圧力となる
ように運転される加熱水系では、前述のように高
純度の給水が使用されており、溶存酸素は7ppb
以下とされている。本発明ではこのような系に加
熱条件下で溶在酸素10ppb以上の水を供給するこ
とにより、金属表面に生成したシリカまたは有機
物スケールを除去する。 In heated water systems that are operated at pressures of 50 Kgf/cm 2 or higher, such as once-through or circulation boiler plants or boiling water or pressurized water nuclear plants, which are often used for power generation, high purity is required as described above. of water supply is used, and dissolved oxygen is 7ppb
The following is considered. In the present invention, silica or organic scale formed on the metal surface is removed by supplying water containing 10 ppb or more of dissolved oxygen to such a system under heating conditions.
本発明において用いられる溶存酸素を10ppb以
上含む脱塩水は、ボイラあるいは原子力プラント
に供給される給水に所定量の酸素を注入すること
により製造できる。この方法に供される給水は、
工業用水や地下水などの原水を脱塩装置で脱塩
し、溶存酸素を除去することにより得られる。 Desalinated water containing 10 ppb or more of dissolved oxygen used in the present invention can be produced by injecting a predetermined amount of oxygen into the feed water supplied to a boiler or nuclear power plant. The water supply supplied to this method is
It is obtained by desalinating raw water such as industrial water or underground water using a desalination equipment to remove dissolved oxygen.
このような給水処理のために使用される脱塩装
置としては強酸性カチオン交換樹脂、弱酸性カチ
オン交換樹脂、強塩基性アニオン交換樹脂、弱塩
基性アニオン交換樹脂などの公知のイオン交換樹
脂を単独または組合せて使用したものがあり、そ
の代表的な処理方法として次のようなものがあ
る。 Desalination equipment used for such water supply treatment uses known ion exchange resins such as strong acid cation exchange resins, weak acid cation exchange resins, strong basic anion exchange resins, and weak basic anion exchange resins. Alternatively, they may be used in combination, and typical processing methods include the following.
Ｈ形強酸性カチオン交換樹脂とOH形強塩基
性アニオン交換樹脂の混床塔。 A mixed bed tower of H type strongly acidic cation exchange resin and OH type strongly basic anion exchange resin.
Ｈ形強酸性カチオン交換樹脂塔−脱炭酸塔−
OH形強塩基性アニオン交換樹脂塔………（２
床３塔型）。 H-type strongly acidic cation exchange resin tower - decarboxylation tower -
OH type strong basic anion exchange resin tower……(2
(3-floor tower type).
Ｈ形強酸性カチオン交換樹脂塔−OH形弱塩
基性アニオン交換樹脂塔−脱炭酸塔−OH形強
塩基性アニオン交換樹脂塔………（３床４塔
型）。 H type strongly acidic cation exchange resin tower - OH type weakly basic anion exchange resin tower - decarboxylation tower - OH type strongly basic anion exchange resin tower... (3 bed 4 tower type).
Ｈ形強酸性カチオン交換樹脂塔−脱炭酸塔−
OH形強塩基性アニオン交換樹脂塔−Ｈ形強酸
性カチオン交換樹脂塔−OH形強塩基性アニオ
ン交換樹脂塔………（４床５塔型）。 H-type strongly acidic cation exchange resin tower - decarboxylation tower -
OH type strong basic anion exchange resin tower - H type strong acidic cation exchange resin tower - OH type strong basic anion exchange resin tower... (4 bed 5 tower type).
イオン交換樹脂を用いた脱塩方法としては上記
に限定されず、たとえば上記の２床３塔型等の後
にさらにシリカポリツシヤあるいは混床式ポリツ
シヤなどを付設したものなども採用可能である。 The desalination method using an ion exchange resin is not limited to the above method, and it is also possible to use, for example, the above-mentioned two-bed, three-column type, followed by a silica polisher or a mixed-bed polisher.
上記のような脱塩装置により得られた脱塩水は
溶存酸素を除去して給水とされるが、このための
溶存酸素除去方法としては、物理的、化学的処理
法が採用できる。物理的処理法としては真空また
は加熱脱気による方法、あるいは水素ガスを供給
して水中の溶存酸素と水素とを反応させる方法な
どがあげられる。一方、化学的処理法としては、
ヒドラジンや亜硫酸塩などの脱酸素剤を添加する
方法があげられる。これらの方法は場合によつて
単独で用いられたり、あるいは組合せて用いられ
る。組合せ方法としては、例えば物理的に脱気処
理した後、脱酸素剤を添加し、さらに水素ガスを
供給する方法などがあげられる。 Desalinated water obtained by the desalting device as described above is used as water supply after removing dissolved oxygen, and physical and chemical treatment methods can be adopted as a method for removing dissolved oxygen for this purpose. Examples of physical treatment methods include a method using vacuum or thermal deaeration, and a method of supplying hydrogen gas to cause dissolved oxygen in water to react with hydrogen. On the other hand, as a chemical treatment method,
An example of this method is to add an oxygen scavenger such as hydrazine or sulfite. These methods may be used alone or in combination depending on the case. Examples of the combination method include, for example, a method of physically degassing, adding an oxygen scavenger, and further supplying hydrogen gas.
こうして得られる脱酸素された脱塩水はそのま
ま通常運転時の給水とできるもので、溶存酸素
7ppb以下、一般的には0ppbとなつているが、こ
れをスケール除去用として使用するには、溶存酸
素を10ppb以上存在させる。この発明において、
シリカや有機物スケールが金属表面から溶出する
のは、溶存酸素が酸化剤として作用するからと考
えられ、10ppbが臨界濃度であることがわかつ
た。溶存酸素量が10ppb未満であると、スケール
除去効果が悪化する。また後述のように高温での
運転中に洗浄を行う場合には、あまりにも多量の
溶存酸素が存在すると腐食の問題が発生するの
で、10〜1000ppbとするのが望ましい。加熱水系
を運休して洗浄する場合は10ppb〜飽和量
（8ppm）でよい。 The deoxygenated desalinated water obtained in this way can be used as feed water during normal operation, and the dissolved oxygen
It is 7ppb or less, generally 0ppb, but in order to use it for scale removal, dissolved oxygen must be present at 10ppb or more. In this invention,
Silica and organic scale are leached from metal surfaces because dissolved oxygen acts as an oxidizing agent, and 10 ppb was found to be the critical concentration. If the amount of dissolved oxygen is less than 10 ppb, the scale removal effect will deteriorate. Further, when cleaning is performed during operation at high temperatures as described below, the presence of too much dissolved oxygen will cause corrosion problems, so it is desirable to set the concentration to 10 to 1000 ppb. If the heating water system is shut down for cleaning, 10 ppb to saturation amount (8 ppm) is sufficient.
脱酸素された給水に酸素を溶解するためには、
給水系に酸素供給管を付設し、必要時に酸素供給
管を通じて酸素を供給し、溶解するのが望ましい
が、加熱水系へ直接酸素を供給してもよい。酸素
源としては酸素ガス、空気、もしくはこれらを窒
素ガスで希釈したもの、または過酸化水素などが
あげられる。また溶存酸素量を制御するために、
必要に応じて水素ガスを用いてもよい。 To dissolve oxygen in deoxygenated feed water,
Although it is desirable to attach an oxygen supply pipe to the water supply system and supply oxygen through the oxygen supply pipe when necessary to dissolve the oxygen, oxygen may also be supplied directly to the heated water system. Examples of the oxygen source include oxygen gas, air, these diluted with nitrogen gas, and hydrogen peroxide. In addition, in order to control the amount of dissolved oxygen,
Hydrogen gas may be used if necessary.
上記は洗浄水として給水を使用する場合につい
て説明したが、給水処理に準じた処理により別途
洗浄水を得てもよい。この場合には溶存酸素の除
去は厳密に行う必要はなく、むしろ飽和量の溶存
酸素を含む脱塩水に、必要に応じて水素ガスなど
を供給し、所定量の溶存酸素を含むように調整す
る方が簡単で好ましい。 Although the above description has been made regarding the case where feed water is used as the wash water, wash water may be separately obtained by processing similar to the water feed treatment. In this case, it is not necessary to strictly remove dissolved oxygen; rather, hydrogen gas or the like is supplied as necessary to the demineralized water containing a saturated amount of dissolved oxygen, and adjustment is made so that it contains a predetermined amount of dissolved oxygen. It is easier and preferable.
加熱水系の洗浄を行う時期は特に限定されない
が、ボイラまたは原子力プラントの定期検査時、
スケールの生成量が一定以上となつたとき、ある
いはスケール量に関係なく一定期間経過したとき
などがあげられる。 There are no particular restrictions on when to clean the heated water system, but during periodic inspections of boilers or nuclear power plants,
Examples include when the amount of scale produced exceeds a certain level, or when a certain period of time has passed regardless of the amount of scale.
洗浄方法は溶存酸素を含む洗浄水または酸素を
加熱水系に供給し、溶存酸素を10ppb以上含む洗
浄水を、温度80℃以上、好ましくは120℃以上で
スケールと接触させ、洗浄水を循環または撹拌し
て洗浄を行う。洗浄操作としては、加熱水系の運
休時に洗浄作業として行うこともできるが、貫流
ボイラなど、給水の全量が蒸気化する系以外の加
圧水系では、運転中に水系の溶存酸素量を高めて
洗浄操作を行うことができる。運休時に洗浄する
場合は、洗浄水槽から洗浄水を系内に供給し、80
℃以上、好ましくは120℃以上で一定時間循環さ
せて洗浄を行うのが望ましい。運転中に洗浄を行
う場合には、腐食を防止するため温度、圧力を若
干下げて洗浄してもよい。 The cleaning method involves supplying cleaning water containing dissolved oxygen or oxygen to a heated water system, bringing the cleaning water containing 10 ppb or more of dissolved oxygen into contact with the scale at a temperature of 80°C or higher, preferably 120°C or higher, and circulating or stirring the cleaning water. and wash. Cleaning operations can be carried out when the heating water system is out of service, but in pressurized water systems other than systems where the entire amount of feed water is vaporized, such as once-through boilers, cleaning operations can be performed by increasing the amount of dissolved oxygen in the water system during operation. It can be performed. When cleaning during service suspension, supply cleaning water into the system from the cleaning water tank and
It is desirable to perform the cleaning by circulating the temperature at 120°C or higher for a certain period of time. When cleaning is performed during operation, the temperature and pressure may be slightly lowered to prevent corrosion.
このような洗浄操作を行うことにより、金属表
面に付着したシリカまたは有機物スケールは除去
され、洗浄水側へ移行する。運休時に洗浄を行う
場合は洗浄終了後、洗浄水を全量排出するが、運
転中に洗浄を行う場合は系内の水（洗浄水）を一
部づつ排出する。 By performing such a cleaning operation, silica or organic scale adhering to the metal surface is removed and transferred to the cleaning water side. When cleaning is performed during service suspension, the entire amount of cleaning water is discharged after cleaning is completed, but when cleaning is performed during operation, the water in the system (cleaning water) is discharged one by one.
排出される洗浄水には多量のシリカまたは有機
物スケール成分が含まれているので、浄化装置に
導入し、環境汚染物質を除去してから放流するの
が望ましい。浄化装置としてはイオン交換樹脂
塔、粉末イオン交換樹脂をプレコートした過装
置、電磁フイルタなどがあげられる。 Since the discharged wash water contains a large amount of silica or organic scale components, it is desirable to introduce it into a purification device, remove environmental pollutants, and then discharge it. Examples of the purification device include an ion exchange resin tower, a filter precoated with powdered ion exchange resin, and an electromagnetic filter.
これらの浄化装置は洗浄水排出系路に設け、洗
浄廃水中のスケール成分等を除去した後放流する
ようにしてもよいが、洗浄水の循環系路内に浄化
装置を設け、洗浄水中の不純物を除去して一部を
放流するとともに、残部を再循環すれば、洗浄効
率がよくなる。またこれらの浄化装置として給水
処理または復水処理用等の既設の設備を利用して
もよい。 These purifiers may be installed in the wash water discharge system and discharged after removing scale components etc. from the wash wastewater, but a purifier may be installed in the wash water circulation system to remove impurities in the wash water. Cleaning efficiency can be improved by removing and discharging a portion, while recirculating the remainder. Furthermore, existing equipment for water supply treatment or condensate treatment may be used as these purification devices.
上記の処理により浄化装置には不純物が捕捉さ
れるが、イオン交換樹脂や電磁フイルタの場合は
必要により再生し、その再生廃液を処理した後廃
棄処分し、粉末イオン交換樹脂の場合には全量を
廃棄処分することができる。特に原子力プラント
の場合は、分離した不純物が放射化しているの
で、粉末イオン交換樹脂を含む材や、電磁フイ
ルタなどから発生する再生廃液は、セメントやプ
ラスチツクによる固化処理等したのち適切な処分
を行う。 Through the above treatment, impurities are captured in the purification device, but in the case of ion exchange resins and electromagnetic filters, they are regenerated as necessary, and the recycled waste liquid is disposed of after being treated, and in the case of powdered ion exchange resins, the entire amount is Can be disposed of. Particularly in the case of nuclear power plants, separated impurities are radioactive, so materials containing powdered ion exchange resin and recycled waste liquid generated from electromagnetic filters should be solidified with cement or plastic before being disposed of appropriately. .
以上のようにしてスケールの洗浄操作が終了す
ると、運転中に洗浄を行つた場合はそのまま通常
運転に移り、運休中に洗浄を行つた場合は洗浄水
を排出後給水を供給し通常運転に移る。 When the scale cleaning operation is completed as described above, if the cleaning was performed during operation, the operation will proceed directly to normal operation, or if the cleaning was performed during suspension of operation, the cleaning water will be drained, water will be supplied, and normal operation will resume. .
なお以上の説明において、洗浄水の溶存酸素は
頭初10ppb以上あればよく、洗浄の途中で10ppb
未満となつても差支えない。また洗浄操作も上記
説明のものに限定されず、任意に変更可能であ
る。さらに除去対象となるスケールもシリカまた
は（および）有機物を主成分として含むものであ
れば、他の成分を含んでいてもよい。また洗浄対
象となる加熱水系もボイラプラントまたは原子力
プラントに限定されない。 In the above explanation, dissolved oxygen in the cleaning water should be at least 10 ppb at the beginning, and 10 ppb or more during cleaning.
There is no problem even if it is less than that. Further, the cleaning operation is not limited to that described above, and can be changed as desired. Furthermore, the scale to be removed may also contain other components as long as it contains silica and/or organic matter as a main component. Furthermore, the heated water system to be cleaned is not limited to boiler plants or nuclear power plants.
以上のとおり、本発明によれば、加熱水系に生
成したシリカまたは有機物スケールに、溶存酸素
を10ppb以上含む脱塩水を、温度80℃以上で接触
させるように構成したので、簡単な作業で安全か
つ効率よくシリカまたは有機物スケールを除去す
ることができ、この洗浄作業は加熱水系の運転中
にも行うことができる。さらに洗浄液として、
酸、アルカリ等の化学薬品を使用する必要がない
ので、洗浄コストを低くするとともに、薬品の残
留によるアフターフエイント等の問題が発生する
ことはなく、洗浄廃液の処理も容易で、放射性廃
棄物等の量も少なくなる。また溶存酸素による腐
食も本発明の実施に要する程度の短時間の接触で
はほとんど問題とならず、従来の化学薬品に比べ
れば腐食性は小さい。 As described above, according to the present invention, desalinated water containing 10 ppb or more of dissolved oxygen is brought into contact with silica or organic scale generated in a heated water system at a temperature of 80°C or higher, so the work is simple and safe. Silica or organic scale can be efficiently removed, and this cleaning work can be performed even while the heated water system is in operation. Furthermore, as a cleaning liquid,
Since there is no need to use chemicals such as acids and alkalis, cleaning costs are reduced, there are no problems such as afterfaint caused by residual chemicals, cleaning waste liquid is easy to dispose of, and radioactive waste can be removed. etc. will also decrease. Further, corrosion caused by dissolved oxygen is hardly a problem when the contact is for a short period of time required for carrying out the present invention, and the corrosivity is small compared to conventional chemicals.
次に本発明の実施例について説明する。 Next, examples of the present invention will be described.
実施例 １
原水を混床式イオン交換樹脂塔を含む脱塩装置
で脱塩した後、真空脱気装置により脱気を行つて
得られた脱塩水にヒドラジン0.5ppmとアンモニ
アを3ppm添加した給水（溶存酸素0ppb）を供給
して２年間蒸気発生を行つた強制循環型ボイラ
（蒸気温度285℃、圧力66Kgｆ／cm2）に生成した有
機性スケールの除去を行つた。上記ボイラ水には
給水から持込まれたリグニンスルホン酸塩が検出
され、若干の着色が見られた。また一旦運休して
ボイラ内のこげ茶色のタール状スケールを取出
し、化学分析したところ、酸化カルシウム２重量
％、シリカ15重量％、強熱減量75.5重量％であつ
た。このボイラ内にシリカスケールの付着したテ
ストピースも併せて吊るし、ボイラの洗浄を開始
した。Example 1 Raw water was desalted using a desalting device including a mixed-bed ion exchange resin tower, and then degassed using a vacuum deaerator. The organic scale formed in a forced circulation boiler (steam temperature 285°C, pressure 66 kgf/cm 2 ) that had been generating steam for two years by supplying dissolved oxygen (0 ppb) was removed. Lignosulfonate brought in from the water supply was detected in the boiler water, and some coloring was observed. After the boiler was temporarily suspended, the dark brown tar-like scale inside the boiler was removed and chemically analyzed, it was found to be 2% by weight of calcium oxide, 15% by weight of silica, and 75.5% by weight of loss on ignition. A test piece with silica scale attached was also hung inside the boiler, and cleaning of the boiler was started.
洗浄にあたつて、まず上記給水に酸素ガスを注
入して溶存酸素を飽和させ、運休中のボイラに供
給した。続いてボイラの温度、圧力を第１図に付
記する値に高めて運転し蒸気を発生させた。この
間給水中に酸素ガスと水素ガスを注入して、溶存
酸素量を第１図に付記する所定量に調整し、洗浄
を行つた。なおボイラのブロー水は全給水量の10
％とした。 For cleaning, oxygen gas was first injected into the feed water to saturate it with dissolved oxygen, and the water was then supplied to the out-of-service boiler. Subsequently, the temperature and pressure of the boiler were raised to the values shown in Figure 1 and the boiler was operated to generate steam. During this time, oxygen gas and hydrogen gas were injected into the water supply to adjust the amount of dissolved oxygen to a predetermined amount as shown in FIG. 1, and cleaning was performed. The blow water of the boiler is 10% of the total water supply amount.
%.
洗浄効果は、有機物スケールの除去状態につい
ては、ブロー水を抜き取り、260nｍの紫外線吸
収測定によりUV値を測定し、またシリカスケー
ルの除去状態についてはJIS−B8224によりボイ
ラ水中のシリカの量を測定した。 The cleaning effect was determined by extracting the blow water and measuring the UV value by measuring ultraviolet absorption at 260 nm to check the removal of organic scale, and by measuring the amount of silica in the boiler water according to JIS-B8224 to check the removal of silica scale. .
紫外線吸収測定結果は第１図のグラフに示す通
りである。この結果より、飽和の溶存酸素が含ま
れていても温度が低い状態では有機物スケールの
溶出効果が悪く、また高温下であつても溶存酸素
が10ppb未満では溶出効果が悪いが、溶存酸素が
10ppb以上で高温の場合には有機物スケールの除
去効果が高いことがわかる。 The ultraviolet absorption measurement results are as shown in the graph of FIG. From this result, even if saturated dissolved oxygen is contained, the elution effect of organic scale is poor at low temperature, and even at high temperature, the elution effect is poor when dissolved oxygen is less than 10 ppb, but dissolved oxygen is
It can be seen that when the temperature is 10 ppb or more and the temperature is high, the organic scale removal effect is high.
一方、ボイラ水中のシリカは常温下では、ボイ
ラ給水（３〜5ppb）の２〜５倍程度しか検出さ
れなかつたが、255℃以上の高温下で溶存酸素が
10ppb以上含まれる状態で、ボイラ給水の15〜20
倍のシリカが検出された。また洗浄後ボイラから
テストピースを取り出したところ、シリカスケー
ルの重量が半減していた。これらの結果、上記条
件下ではシリカスケールが効果的に溶出し、除去
効果が高いことがわかる。 On the other hand, silica in boiler water was only detected at room temperature, about 2 to 5 times that of boiler feed water (3 to 5 ppb), but dissolved oxygen was detected at high temperatures of 255°C or higher.
15-20% of boiler feed water containing 10ppb or more
twice as much silica was detected. When the test piece was removed from the boiler after cleaning, the weight of the silica scale was reduced by half. These results show that under the above conditions, silica scale is effectively eluted and the removal effect is high.
実施例 ２
実施例１で用いたスケール付着ボイラのチユー
ブを３cm×３cmの大きさに切り出し、これをガラ
スフツクで吊るし、還流器付きフラスコ中に挿入
した。次にこのフラスコ中に溶存酸素を8ppm
（飽和）含む脱塩水500mlを供給し、ウオーターバ
スにより水温を40℃、80℃、100℃に設定して有
機物スケール成分の溶出量を実施例１と同様の方
法で測定した。Example 2 The tube of the scaled boiler used in Example 1 was cut into a size of 3 cm x 3 cm, hung with a glass hook, and inserted into a flask equipped with a reflux device. Next, add 8ppm of dissolved oxygen to this flask.
500 ml of demineralized water (saturated) was supplied, and the water temperature was set at 40°C, 80°C, and 100°C using a water bath, and the amount of organic scale components eluted was measured in the same manner as in Example 1.
結果を第２図のグラフに示す。これから水温が
80℃以上になると、スケール成分の溶出効果が大
になることがわかる。 The results are shown in the graph of FIG. The water temperature is about to change
It can be seen that when the temperature exceeds 80°C, the elution effect of scale components increases.
第１図および第２図は実施例１および２におけ
る紫外線吸収測定結果を示すグラフである。
1 and 2 are graphs showing the ultraviolet absorption measurement results in Examples 1 and 2.
Claims (1)
る加熱水系の内壁面に生成したシリカまたは有機
物スケールに、溶存酸素を10ppb以上含む脱塩水
を、80℃以上の状態で接触させることを特徴とす
るスケールの除去方法。 ２ 溶存酸素を10ppb以上含む脱塩水は脱塩およ
び脱酸素された水に酸素ガス、空気または過酸化
水素を注入した水である特許請求の範囲第１項記
載のスケールの除去方法。 ３ スケールと溶存酸素を10ppb以上含む脱塩水
の接触は加熱水系の運転中に行うようにした特許
請求の範囲第１項または第２項記載のスケールの
除去方法。 ４ 加熱水系はボイラプラントまたは原子力プラ
ントである特許請求の範囲第１項ないし第３項の
いずれかに記載のスケールの除去方法。[Claims] 1. Demineralized water containing 10 ppb or more of dissolved oxygen is added to the silica or organic scale formed on the inner wall surface of a heated water system to which high-purity water with dissolved oxygen of 7 ppb or less is supplied at a temperature of 80°C or higher. A scale removal method characterized by contacting. 2. The method for removing scale according to claim 1, wherein the desalted water containing 10 ppb or more of dissolved oxygen is water obtained by injecting oxygen gas, air, or hydrogen peroxide into desalted and deoxygenated water. 3. The method for removing scale according to claim 1 or 2, wherein the contact between the scale and demineralized water containing 10 ppb or more of dissolved oxygen is carried out during operation of the heated water system. 4. The scale removal method according to any one of claims 1 to 3, wherein the heated water system is a boiler plant or a nuclear power plant.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13892782A JPS5929093A (en) | 1982-08-10 | 1982-08-10 | Method for removing scale |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP13892782A JPS5929093A (en) | 1982-08-10 | 1982-08-10 | Method for removing scale |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS5929093A JPS5929093A (en) | 1984-02-16 |
| JPS6222680B2 true JPS6222680B2 (en) | 1987-05-19 |
Family
ID=15233385
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP13892782A Granted JPS5929093A (en) | 1982-08-10 | 1982-08-10 | Method for removing scale |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS5929093A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6280241A (en) * | 1985-10-01 | 1987-04-13 | Tanaka Denshi Kogyo Kk | Copper wire for bonding semiconductor device |
| FR2708628B1 (en) * | 1993-07-29 | 1997-07-18 | Framatome Sa | Method of chemical cleaning of metallic material parts. |
| JP5022266B2 (en) * | 2008-02-18 | 2012-09-12 | 三菱重工業株式会社 | Boiler operation method and boiler control device |
| US20230279313A1 (en) | 2022-03-01 | 2023-09-07 | Kurita Water Industries Ltd. | Cleaning agent, cleaning method of water treatment apparatus, and cleaning method of silica-based scale |
-
1982
- 1982-08-10 JP JP13892782A patent/JPS5929093A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS5929093A (en) | 1984-02-16 |
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