JP5295819B2 - Sea life adhesion prevention method - Google Patents
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本発明は、装置や設備において、海生物の付着を防止する海生物付着防止方法に関する。 The present invention relates to a marine organism adhesion prevention method for preventing marine organism adhesion in an apparatus or facility.
海水を取水するプラントにおいて、海水中の細菌や大型生物が付着する等の汚れによって、機器・配管類の性能や健全性が損なわれ、エネルギーを浪費する。例えば、フジツボ、二枚貝等の海生物が海水管系統に付着すると、通路を閉塞し、海水流量の不足により主機関や補機がオーバーヒートするという重大な影響を及ぼすおそれがある。また、スライム（主として微生物の繁殖によって生じる粘性塊状・泥状物質）が熱交換器の伝熱面に付着すると、これが被膜となって海水の熱交換を妨げるおそれがある。このため、これらの問題を解決するために、海洋生物の付着を防止する方法が提案されている。例えば、細菌や大型生物の付着を防止すべき箇所に、汚れ止め機能を有する水中防汚材を塗装することが知られている（特許文献１）。また、塩素系の殺菌剤（電解塩素、次亜塩素酸ソーダ等）を取水路中の海水に注入する塩素処理が知られている（特許文献２）。さらには、塩素系の殺菌剤を注入することなく、燃焼排ガスを海水に吹き込むことにより二酸化炭素を注入して、海水のｐＨを５〜６に低下させる方法が知られている（特許文献３）。 In a plant that takes in seawater, dirt such as adhesion of bacteria and large organisms in seawater impairs the performance and soundness of equipment and piping, and wastes energy. For example, when marine organisms such as barnacles and bivalves adhere to the seawater pipe system, the passage may be blocked and the main engine and auxiliary equipment may overheat due to insufficient seawater flow rate. In addition, when slime (viscous lump or mud substance produced mainly by the propagation of microorganisms) adheres to the heat transfer surface of the heat exchanger, it may become a film and hinder heat exchange of seawater. For this reason, in order to solve these problems, a method for preventing adhesion of marine organisms has been proposed. For example, it is known that an underwater antifouling material having an antifouling function is applied to a portion where adhesion of bacteria and large organisms should be prevented (Patent Document 1). Further, chlorination treatment in which a chlorine-based disinfectant (electrolytic chlorine, sodium hypochlorite, etc.) is injected into seawater in a water channel is known (Patent Document 2). Furthermore, a method of injecting carbon dioxide by blowing combustion exhaust gas into seawater without injecting a chlorine-based disinfectant to lower the pH of seawater to 5 to 6 is known (Patent Document 3). .
前記特許文献１に記載のように防汚塗装を施すものは、径の細い配管や水抜きができない場所には施工できないという問題がある。また、効果に寿命があるので、寿命となると設備の運用を一旦休止して塗り替えなければならず、その間継続して使用ができないという問題や、手間やコストがかかるという問題がある。 As described in the above-mentioned Patent Document 1, the antifouling coating has a problem that it cannot be applied to a pipe having a small diameter or a place where water cannot be drained. In addition, since the effect has a lifetime, there is a problem that when the lifetime reaches the end, the operation of the facility must be paused and repainted.
また、特許文献２に記載のように塩素処理を施すものは、全ての範囲に適用でき、運転を継続しながら実施することができるが、次亜塩素酸等が消費されて残留塩素が減衰するという問題がある。つまり、残留塩素による海洋生物への影響を考慮して、放水の残留塩素濃度が検出されない濃度で処理することが条件となっている。このために、設備の下流部や支流部において、海生物の付着防止に有効な残留塩素濃度が保持できないことが原因で被害が発生するおそれがある。また、塩素処理で許容される最大の濃度で処理が行われているため、環境に及ぼす影響を最小限度に抑えることができない。さらには、常にある一定濃度で処理が行われるため、付着する海生物の幼生密度の変化に応じて濃度を変化させる等して対応することができない。 In addition, those subjected to chlorination as described in Patent Document 2 can be applied to the entire range and can be carried out while continuing the operation. However, hypochlorous acid and the like are consumed, and residual chlorine is attenuated. There is a problem. In other words, in consideration of the effect of residual chlorine on marine organisms, it is a condition that the residual chlorine concentration of the discharged water is treated at a concentration that is not detected. For this reason, damage may occur due to the fact that the residual chlorine concentration effective in preventing the adhesion of marine organisms cannot be maintained in the downstream part or the tributary part of the facility. In addition, since the treatment is performed at the maximum concentration permitted by the chlorination, the influence on the environment cannot be minimized. Furthermore, since the treatment is always performed at a certain constant concentration, it cannot be coped with by changing the concentration according to the change in the larval density of the attached marine organisms.
特許文献３に記載のものは、塩素処理を行う必要がないため、前記したような塩素処理により生じる弊害は解消することができる。しかしながら、特許文献３に記載されている方法、つまり、燃焼排ガスを吹き込むことによって二酸化炭素を注入する方法でｐＨを５〜６に下げると、多量の燃焼排ガスを使用しなければならず、現実的ではない。また、海生物の殻の生成を抑えることを目的としてｐＨを５〜６としているため、有機物の付着防止には効果があるが、スライム等の無機物の付着までも抑えられるものではない。しかも、ｐＨが５〜６のような低いｐＨ環境では魚等に悪影響を及ぼすおそれがあり、好ましい環境ではない。このため、海水のｐＨを低下させると同時に適度な範囲に留めることが必要であり、必要最小限のｐＨに調整する必要がある。また、前記のような低いｐＨ環境は、水質規制値（公共用水域水質環境基準）の範囲外であり、放流すると環境汚染が発生する。従って、一旦このような低いｐＨ環境とすると、別の装置を用いて再度ｐＨを高くし、水質規制値（公共用水域水質環境基準）の範囲内にまで戻す必要がある。従って、工程数の増加や、コストの増加という問題を招来することになる。 Since the thing of patent document 3 does not need to perform a chlorination, the bad effect which arises by the above chlorinations can be eliminated. However, if the pH is lowered to 5 to 6 by the method described in Patent Document 3, that is, the method in which carbon dioxide is injected by blowing combustion exhaust gas, a large amount of combustion exhaust gas must be used, which is realistic. is not. In addition, since the pH is set to 5 to 6 for the purpose of suppressing the formation of shells of marine organisms, it is effective in preventing the adhesion of organic substances, but it does not suppress the adhesion of inorganic substances such as slime. Moreover, in a low pH environment such as 5 to 6, there is a possibility of adversely affecting fish and the like, which is not a preferable environment. For this reason, it is necessary to lower the pH of seawater and at the same time keep it within an appropriate range, and it is necessary to adjust to the minimum necessary pH. Moreover, such a low pH environment is outside the range of the water quality regulation value (public water area water quality environmental standard), and environmental pollution occurs when discharged. Therefore, once such a low pH environment is established, it is necessary to increase the pH again using another device and return it to within the range of the water quality regulation value (public water area water quality environmental standard). Therefore, the problem of an increase in the number of processes and an increase in cost is caused.
そこで、本発明は、上記課題に鑑みて、長期にわたって効果が減衰することがなく、しかも付着する海生物の種類や幼生密度の変化に応じて対応できて環境保全と省エネルギーを図ることができる海生物付着防止方法を提供する。 Therefore, in view of the above-mentioned problems, the present invention is a sea where the effect is not attenuated over a long period of time, and it is possible to cope with changes in the type of sea creatures attached and the density of larvae, thereby achieving environmental conservation and energy saving. A method for preventing biofouling is provided.
本発明の海生物付着防止方法は、海水流路から取水した海水を混合部にて減圧しつつ、その減圧された海水に、ガス流路から導入した二酸化炭素ガスを、海水との体積混合比である（二酸化炭素ガス／海水）を０．１〜４／１００として注入することにより、海水中に、直径寸法が十〜数十μｍである二酸化炭素ガスのマイクロバブルを発生させ、このマイクロバブルにて二酸化炭素ガスを海水に溶解させて海水のｐＨを６．４〜８．１の範囲内とし、前記ｐＨ範囲内での海生物の付着防止を可能とするものである。本発明において、海生物とは、フジツボ、二枚貝等の有機物、及び微生物の繁殖によって生じる粘性塊状・泥状物質等の無機物（いわゆるスライム）を含むものとする。 The method of preventing adhesion of marine organisms of the present invention is to reduce the seawater taken from the seawater channel at the mixing unit, while reducing the volume of carbon dioxide gas introduced from the gas channel into the decompressed seawater, by that enter Note as a (carbon dioxide / sea) of 0.1 to 4/100 is, in seawater, to generate microbubbles of carbon dioxide gas diameter is ten to several tens of [mu] m, this Carbon dioxide gas is dissolved in seawater with microbubbles so that the pH of the seawater is in the range of 6.4 to 8.1, and adhesion of marine organisms within the pH range is enabled. In the present invention, marine organisms include organic substances such as barnacles and bivalves, and inorganic substances (so-called slime) such as viscous massive and mud substances produced by the propagation of microorganisms.
本発明の海生物付着防止方法では、直径寸法が十〜数十μｍの二酸化炭素のマイクロバブルを発生させ、二酸化炭素ガスを海水に溶解しやすくして、海水に均一に分散させる。すなわち、発生したマイクロバブルは、海水中で表面積が大となり、海水への二酸化炭素ガスの溶解が促進される。これにより、効率よくｐＨを６．４〜８．１に下げることができて、このｐＨ範囲内での海生物の付着を防止することができる。なお、海生物（特に、貝類等の殻を有する有機物）の付着防止には、低いｐＨ範囲である程、殻の生成抑止効果が高く、海生物の付着防止には効果的である。ところが、ｐＨが６．４未満（例えば、ｐＨ５〜６）のような低いｐＨ環境では魚等に悪影響を及ぼすおそれがあり、好ましい環境ではない。そこで、ｐＨ６．４〜８．１の中性領域又はその近傍とすることにより、海水のｐＨを低下させると同時に適度な範囲に留めることができ、必要最小限のｐＨとすることができる。これにより、魚等に悪影響を及ぼすことなく低いｐＨ環境を実現することができる。また、ｐＨ６．４〜８．１の中性領域又はその近傍では、水質規制値（公共用水域水質環境基準）の範囲内であるため、再度ｐＨを高くするという作業、及びそれに用いる装置を省略することができる。 In the method for preventing adhesion of marine organisms according to the present invention, microbubbles of carbon dioxide having a diameter of 10 to several tens of μm are generated so that carbon dioxide gas is easily dissolved in seawater and uniformly dispersed in seawater. That is, the generated microbubbles have a large surface area in the seawater, and the dissolution of the carbon dioxide gas in the seawater is promoted. Thereby, pH can be efficiently lowered | hung to 6.4-8.1 and adhesion of the marine organism within this pH range can be prevented. In addition, for the prevention of adhesion of marine organisms (particularly, organic substances having shells such as shellfish), the lower the pH range, the higher the effect of inhibiting the formation of shells, and the more effective the prevention of adhesion of marine organisms. However, a low pH environment such as a pH of less than 6.4 (for example, pH 5 to 6) may adversely affect fish and the like, and is not a preferable environment. Then, by setting it as the neutral region of pH 6.4-8.1 or its vicinity, the pH of seawater can be lowered | hung and it can be kept in a moderate range, and it can be set as required minimum pH. Thereby, a low pH environment can be realized without adversely affecting fish or the like. In addition, in the neutral region of pH 6.4 to 8.1 or in the vicinity thereof, it is within the range of the water quality regulation value (public water area water quality environmental standard), so the work of increasing the pH again and the apparatus used therefor are omitted. can do.
（二酸化炭素ガス／海水）が１〜４／１００の範囲内では、ｐＨは６．４以上、７．７以下の範囲となる。この場合、比較的低いｐＨ範囲となり、このｐＨ範囲内で有機物の付着の抑止効果が高まるとともに、スライム等の無機物の付着も防止することができる。一方、（二酸化炭素ガス／海水）が０．１〜１未満／１００の範囲内では、ｐＨは７．７を越え、８．１以下となる。この場合、比較的高いｐＨ範囲となり、このｐＨ範囲内で、特にスライム等の無機物の付着を防止することができる。このようにして、海水とガスとの比が１００対０．１〜４の範囲内において、付着する海生物の種類や幼生密度の変化に応じてガスの注入量を調整することができる。 When (carbon dioxide gas / seawater) is in the range of 1 to 4/100, the pH is in the range of 6.4 to 7.7. In this case, the pH range is relatively low, and within this pH range, the effect of suppressing the adhesion of organic substances is enhanced, and the adhesion of inorganic substances such as slime can also be prevented. On the other hand, when (carbon dioxide gas / seawater) is in the range of less than 0.1 to less than 1/100, the pH exceeds 7.7 and is 8.1 or less. In this case, it becomes a relatively high pH range, and adhesion of inorganic substances such as slime can be prevented within this pH range. In this way, the amount of gas injected can be adjusted in accordance with changes in the type of marine organisms attached and the larval density when the ratio of seawater to gas is in the range of 100 to 0.1-4.
二酸化炭素ガスを注入することにより、環境保全を図りつつ海水を酸化させることができる。特に、二酸化炭素は発電所等の排ガス中に１０〜１３％程度含まれており、無償の廃棄物となっている。この二酸化炭素を、海生物の付着の防止が必要な海水設備の上流で海中に注入することによって、排ガスを有効利用できる。 By injecting carbon dioxide gas, it is possible to oxidize seawater while protecting the environment. In particular, carbon dioxide is contained about 10 to 13% in exhaust gas from power plants and the like, and is a free waste. By injecting this carbon dioxide into the sea upstream of a seawater facility that needs to prevent the adhesion of marine organisms, the exhaust gas can be used effectively.
しかも、前記したように、二酸化炭素ガスをマイクロバブルの状態で海水に溶解させると、海水中でその表面積を大とすることができるため、注入する二酸化炭素のガス量を少なくすることができる。なお、１個体のマイクロバブルとは体積が小さな微細な気泡をいい、本発明では、発生させるマイクロバブルの直径寸法を十〜数十μｍとしている。仮にマイクロバブルの直径寸法が１００μｍ以上のサイズであると、バブルが浮上して泡と水とが分離され、海生物の付着を十分に防止することができない。そこで、本発明ではマイクロバブルの直径寸法を十〜数十μｍとすることにより、バブルが浮上することなく海水中に均一に分散させることができて、海生物の付着防止効果を一層高めることができる。 In addition, as described above, when carbon dioxide gas is dissolved in seawater in the form of microbubbles, the surface area can be increased in seawater, so that the amount of carbon dioxide gas to be injected can be reduced. A single microbubble refers to a fine bubble having a small volume. In the present invention, the diameter of a microbubble to be generated is set to 10 to several tens of μm. If the diameter of the microbubble is 100 μm or more, the bubble rises and the foam and water are separated, and the adhesion of marine life cannot be sufficiently prevented. Therefore, in the present invention, by setting the diameter size of the microbubbles to 10 to several tens of μm, the bubbles can be uniformly dispersed in the seawater without rising, and the effect of preventing the adhesion of marine organisms can be further enhanced. it can.
本発明の他の海生物付着防止方法は、海水流路から取水した海水を混合部にて減圧しつつ、その減圧された海水に、ガス流路から導入した大気、又は窒素のガスを、海水との体積混合比である（ガス／海水）を０．１〜４／１００として注入することにより、海水中に、直径寸法が十〜数十μｍである前記ガスのマイクロバブルを発生させ、このマイクロバブルを海水に分散させて、マイクロバブルが海生物を擦り取ることにより海生物の付着防止が可能なものである。 Another method for preventing adhesion of marine organisms according to the present invention is to reduce the seawater taken from the seawater flow path in the mixing section, while the atmosphere or nitrogen gas introduced from the gas flow path into the depressurized seawater, is a volume mixing ratio of the by entering Note as a (gas / seawater) to 0.1 to 4/100, in seawater, to generate microbubbles of the gas diameter is ten to several tens of μm The microbubbles are dispersed in seawater, and the microbubbles scrape off the marine organisms, thereby preventing the attachment of marine organisms.
本発明の他の海生物付着防止方法では、海水とガスとの混合比を０．１〜４／１００として、ガスを海水に注入することによりマイクロバブルを発生させると、マイクロバブルの表面積が大となるため、海水にガスを均一に分散させることができる。しかも、ガスは大気、又は窒素を使用しているので、ガスが海水に溶存することなく、多数の微細な泡として海水に存在する。この泡が、海水中にある各種の装置や設備に付着した海生物を擦り取って、海生物の付着を防止することができる。さらに、海水とガスとの比が１００対０．１〜４の範囲内において、海生物の幼生密度の変化によりガスの注入量を調整することができる。 In another method for preventing adhesion of marine organisms of the present invention, when microbubbles are generated by injecting gas into seawater at a mixing ratio of seawater and gas of 0.1 to 4/100, the surface area of the microbubbles is large. Therefore, the gas can be uniformly dispersed in the seawater. Moreover, since the gas uses the atmosphere or nitrogen, the gas does not dissolve in the seawater, but exists in the seawater as a large number of fine bubbles. These bubbles can scrape off the sea creatures attached to various devices and facilities in the seawater, thereby preventing the attachment of sea creatures. Furthermore, when the ratio of seawater to gas is in the range of 100 to 0.1-4, the amount of gas injected can be adjusted by changing the larval density of marine organisms.
本発明の海生物付着防止方法によれば、前記ｐＨの範囲内において効果的に海生物の付着を防止することができ、特に発電所で主な被害の対象となっている海水中の生物の付着、及び設備の表面に被膜を形成するスライムの付着を、少ないガス量で効率よく防止することができる。しかも、設備の寿命によるメンテナンスや設備の入替作業を省略することができ、設備の運用を継続しながら実施できるとともに、低コスト化を図ることができる。また、設備を長年使用しても効果が減衰することがなく、さらには、ガスの注入量を調整することができるため、付着する海生物の幼生密度の変化やスライム層の厚み及び付着範囲に応じて対応でき、環境に及ぼす影響を最小限度に抑えつつ行えるため、環境保全と省エネルギーを図ることができる。 According to the method for preventing adhesion of marine organisms of the present invention, it is possible to effectively prevent the adhesion of marine organisms within the above pH range, and particularly for the organisms in the seawater that are the main targets of damage in power plants. Adhesion and adhesion of slime that forms a film on the surface of the equipment can be efficiently prevented with a small amount of gas. In addition, maintenance due to the life of the equipment and replacement work of the equipment can be omitted, and the equipment can be implemented while continuing the operation, and the cost can be reduced. In addition, even if the equipment is used for many years, the effect is not attenuated, and furthermore, the amount of gas injection can be adjusted, so the change in the larval density of the attached sea life, the thickness of the slime layer and the range of attachment It is possible to respond accordingly, and it can be performed while minimizing the impact on the environment, so that environmental conservation and energy saving can be achieved.
マイクロバブルを発生させた後の海水のｐＨを６．４〜８．１にすると、再度ｐＨを高くするという作業、及びそれに用いる装置を省略することができ、作業効率の向上、及びコストの低減を図ることができる。 When the pH of the seawater after generating microbubbles is 6.4 to 8.1, the work of increasing the pH again and the apparatus used therefor can be omitted, improving work efficiency and reducing costs. Can be achieved.
前記ガスを二酸化炭素ガスとすると、ｐＨ調整機器等の設備が不要となり、また、排ガスを有効利用できて低コスト化を図ることができる。さらに、二酸化炭素は熱交換器の熱伝導に影響を与えないので、省エネルギー効果を一層期待することができる。加えて、二酸化炭素は短時間で海水中に溶解し、ｐＨを容易に６．４〜８．１とすることができる。なお、二酸化炭素は大気中へ排出されると、環境に悪影響を及ぼすことが知られている一方で、二酸化炭素は一旦海水中に溶け込むと大気中へ出にくいことがわかっている。本発明では海水中に二酸化炭素を溶解させているので、二酸化炭素が大気中へ出る可能性は少なく、環境に悪影響を及ぼすおそれは少ない。 When the gas is carbon dioxide gas, equipment such as a pH adjusting device is not required, and the exhaust gas can be used effectively to reduce the cost. Furthermore, since carbon dioxide does not affect the heat conduction of the heat exchanger, an energy saving effect can be further expected. In addition, carbon dioxide dissolves in seawater in a short time, and the pH can be easily adjusted to 6.4 to 8.1. It is known that when carbon dioxide is discharged into the atmosphere, it is known to have an adverse effect on the environment. On the other hand, it is known that carbon dioxide is not easily released into the atmosphere once dissolved in seawater. In the present invention, since carbon dioxide is dissolved in seawater, there is little possibility of carbon dioxide being released into the atmosphere, and there is little risk of adverse effects on the environment.
本発明の他の海生物付着防止方法のように、海水に注入するガスを大気とすると、ボンベやタンク等の設備を省略することができ、装置全体の大型化を防止することができる、コストの低減を図ることができる等の利点がある。一方、窒素ガスとすると、大気と比較して海生物の付着を一層防止することができる。 If the gas injected into the seawater is the atmosphere, as in other methods for preventing attachment of marine organisms of the present invention, equipment such as cylinders and tanks can be omitted, and the overall size of the apparatus can be prevented from increasing. There are advantages such as being able to achieve reduction. On the other hand, when nitrogen gas is used, adhesion of marine organisms can be further prevented as compared with the atmosphere.
以下、本発明を実施するための形態について説明する。 Hereinafter, modes for carrying out the present invention will be described.
本発明の海生物付着防止方法は、海水を取水して利用する装置や設備において、海生物の付着を防止するものである。図１に示すマイクロバブル発生装置１０に海水が流れる場合について説明する。本発明において「海生物」とは、フジツボ、二枚貝等の有機物、及び微生物の繁殖によって生じる粘性塊状・泥状物質等の無機物（いわゆるスライム）を含むものとする。 The marine organism adhesion preventing method of the present invention prevents marine organisms from adhering in an apparatus or facility that takes in and uses seawater. The case where seawater flows into the microbubble generator 10 shown in FIG. 1 will be described. In the present invention, “marine life” includes organic substances such as barnacles and bivalves, and inorganic substances (so-called slime) such as viscous massive and mud substances generated by the propagation of microorganisms.
マイクロバブル発生装置１０は、その両端が海水を送液するための配管（図示省略）に接続される。マイクロバブル発生装置１０は下流側に開口し、配管から送液される海水が流入し流出する海水流路１２が形成されている。海水流路１２は、周方向に沿って等間隔で（図示例では１２０°ピッチ）設けられている。 Both ends of the microbubble generator 10 are connected to piping (not shown) for feeding seawater. The microbubble generator 10 is opened on the downstream side, and a seawater flow path 12 through which seawater fed from a pipe flows in and out is formed. The seawater channel 12 is provided at equal intervals along the circumferential direction (120 ° pitch in the illustrated example).
マイクロバブル発生装置１０には、海水に混合するガスを導入するガス流路１１が配置され、ガス流路１１は、マイクロバブル発生装置１０の径方向に沿って延びて、マイクロバブル発生装置１０の外径側に開口する径方向部１３と、マイクロバブル発生装置１０の軸方向に沿って延びて、マイクロバブル発生装置１０の下流側に開口する軸方向部１４とからなる。ガス流路１１の軸方向部１４は、マイクロバブル発生装置１０の軸心に設けられ、ガス流路１１の外周側に海水流路１２が設けられている。 The microbubble generator 10 is provided with a gas flow path 11 for introducing a gas to be mixed with seawater. The gas flow path 11 extends along the radial direction of the microbubble generator 10 and It consists of a radial portion 13 that opens to the outer diameter side, and an axial portion 14 that extends along the axial direction of the microbubble generator 10 and opens downstream of the microbubble generator 10. An axial portion 14 of the gas flow path 11 is provided at the axial center of the microbubble generator 10, and a seawater flow path 12 is provided on the outer peripheral side of the gas flow path 11.
次に、本発明の第１実施形態に係る海生物付着防止方法を用いて海生物の付着を防止する方法を説明する。取水した海水は、矢印Ａのようにマイクロバブル発生装置１０の海水流路１２を流れ、下流側の開口部近傍で減圧される（例えば、海水流量３０Ｌ／ｍｉｎ、圧力約０．０８ＭＰａ）。そして、矢印Ｂのように、ガス流路１１から二酸化炭素ガスを注入する。この場合、海水と二酸化炭素ガスとの比を１００対０．１〜４とする。これにより、混合部１５にて、減圧された海水に二酸化炭素ガスが溶解して直径寸法が十〜数十μｍのマイクロバブルを発生することができる。マイクロバブルとは、表面積が小さな微細な気泡をいう。マイクロバブルが多量に発生すると、マイクロバブルの表面積が大となるため、海水に対してガスの溶解が促進される。そして、海水にガスが均一に分散され、海水のｐＨを６．４〜８．１に低下させる。このようにしてｐＨが低下された海水がマイクロバブル発生装置の先端から矢印Ｃの方向に流出し、流出した液体を、海生物の付着の防止が必要な海水設備の上流で海中に注入する。これにより、前記ｐＨ範囲内において、海生物の付着を防止することができる。 Next, a method for preventing adhesion of marine organisms using the marine organism adhesion preventing method according to the first embodiment of the present invention will be described. The taken seawater flows through the seawater flow path 12 of the microbubble generator 10 as indicated by an arrow A, and is depressurized in the vicinity of the downstream opening (for example, seawater flow rate 30 L / min, pressure about 0.08 MPa). Then, as indicated by an arrow B, carbon dioxide gas is injected from the gas flow path 11. In this case, the ratio of seawater to carbon dioxide gas is 100 to 0.1-4. Thereby, in the mixing part 15, carbon dioxide gas melt | dissolves in the decompressed seawater, and a microbubble with a diameter dimension of ten to several dozen micrometers can be generated. A microbubble means a fine bubble with a small surface area. When a large amount of microbubbles is generated, the surface area of the microbubbles is increased, so that the dissolution of gas in seawater is promoted. And gas is uniformly disperse | distributed to seawater and the pH of seawater is reduced to 6.4-8.1. The seawater whose pH has been lowered in this way flows out from the tip of the microbubble generator in the direction of arrow C, and the outflowed liquid is injected into the sea upstream of the seawater facility where it is necessary to prevent the attachment of marine organisms. Thereby, adhesion of marine organisms can be prevented within the pH range.
注入する二酸化炭素のガス量は、外部の環境、海生物の除去対象となる設備等に応じて適宜決定することができる。例えば、有機物が多量に発生する環境や、海水管系統のように、有機物が設備の性能に特に悪影響を及ぼす場合等では、（二酸化炭素ガス／海水）を１〜４／１００とするのが好ましい。このとき、ｐＨは６．４以上、７．７以下の範囲となって、特に有機物の付着を抑えることができ、スライムの付着も併せて抑えることができる。一方、熱交換器プレートのように、スライムの付着が設備の性能に特に悪影響を及ぼす場合等では、（二酸化炭素ガス／海水）を０．１〜１未満／１００とするのが好ましい。このとき、ｐＨは７．７越え、８．１以下となって、特にスライム等の無機物の付着を抑えることができる。 The amount of carbon dioxide gas to be injected can be appropriately determined according to the external environment, the equipment to be removed from the sea life, and the like. For example, in an environment where a large amount of organic matter is generated or when the organic matter has a particularly bad influence on the performance of the facility, such as a seawater pipe system, it is preferable to set (carbon dioxide gas / seawater) to 1 to 4/100. . At this time, pH becomes the range of 6.4 or more and 7.7 or less, especially the adhesion of organic matter can be suppressed, and the adhesion of slime can also be suppressed. On the other hand, it is preferable that (carbon dioxide gas / seawater) is less than 0.1 to less than 1/100 in the case where the adhesion of the slime has a particularly bad influence on the performance of the equipment as in the heat exchanger plate. At this time, the pH exceeds 7.7 and is 8.1 or less, and in particular, adhesion of inorganic substances such as slime can be suppressed.
このように、本発明の第１実施形態の海生物付着防止方法は、前記ｐＨの範囲内において効果的に海生物の付着を防止することができ、特に発電所で主な被害の対象となっている海水中の生物の付着、及び設備の表面に被膜を形成するスライムの付着を、少ないガス量で効率よく防止することができる。しかも、設備の寿命によるメンテナンスや設備の入替作業を省略することができ、設備の運用を継続しながら実施できるとともに、低コスト化を図ることができる。また、設備を長年使用しても効果が減衰することがなく、さらには、ガスの注入量を調整することができるため、付着する海生物の幼生密度の変化やスライム層の厚み及び付着範囲に応じて対応でき、環境に及ぼす影響を最小限度に抑えつつ行えるため、環境保全と省エネルギーを図ることができる。 As described above, the method for preventing adhesion of marine organisms according to the first embodiment of the present invention can effectively prevent the adhesion of marine organisms within the range of the pH, and is a main target of damage particularly in power plants. The adhesion of living organisms in the seawater and the adhesion of slime that forms a film on the surface of the facility can be efficiently prevented with a small amount of gas. In addition, maintenance due to the life of the equipment and replacement work of the equipment can be omitted, and the equipment can be implemented while continuing the operation, and the cost can be reduced. In addition, even if the equipment is used for many years, the effect is not attenuated, and furthermore, the amount of gas injection can be adjusted, so the change in the larval density of the attached sea life, the thickness of the slime layer and the range of attachment It is possible to respond accordingly, and it can be performed while minimizing the impact on the environment, so that environmental conservation and energy saving can be achieved.
また、第２実施形態として、海水との混合比である（ガス／海水）を０．１〜４／１００として、大気又は窒素を海水に注入することもできる。この場合も、海水中にガスのマイクロバブルを発生させることにより、マイクロバブルの表面積が大となるため、海水にガスを均一に分散させることができる。しかも、ガスは海水に溶解しにくい大気又は窒素ガスを使用しているので、ガスが海水に溶存しにくく、多数の微細な泡として海水に存在する。この泡が、海水中にある各種の装置や設備に付着した海生物を擦り取って、海生物の付着を防止することができる。このようにして微細な泡が形成された海水がマイクロバブル発生装置の先端から図１の矢印Ｃの方向に流出し、流出した液体を海生物の付着の防止が必要な海水設備の上流で海中に注入する。これにより、貝やフジツボ等の有機物やスライム等の無機物を擦り取ることができ、これらの生物の付着を防止することができる。 Moreover, as 2nd Embodiment, air | atmosphere or nitrogen can also be inject | poured into seawater by setting (gas / seawater) which is a mixing ratio with seawater to 0.1-4 / 100. Also in this case, the surface area of the microbubbles is increased by generating gas microbubbles in the seawater, so that the gas can be uniformly dispersed in the seawater. Moreover, since the gas uses air or nitrogen gas that is difficult to dissolve in seawater, the gas is difficult to dissolve in seawater and exists in seawater as many fine bubbles. These bubbles can scrape off the sea creatures attached to various devices and facilities in the seawater, thereby preventing the attachment of sea creatures. The seawater in which fine bubbles are formed in this way flows out from the tip of the microbubble generator in the direction of arrow C in FIG. 1, and the outflowed liquid enters the sea upstream of the seawater facility where it is necessary to prevent the attachment of marine organisms. Inject. Thereby, organic substances, such as a shellfish and a barnacle, and inorganic substances, such as slime, can be scraped off and adhesion of these living organisms can be prevented.
このように、本発明の第２実施形態の海生物付着防止方法によれば、マイクロバブルを発生させることによって、マイクロバブルを均一に分散させることができ、海水に多数の微細な泡を発生させることができる。この泡が供給されると、貝やフジツボ、スライム等の海生物を擦り取ることができ、これらの海生物の付着を防止することができる。 Thus, according to the marine organism adhesion prevention method of the second embodiment of the present invention, by generating microbubbles, the microbubbles can be uniformly dispersed, and a large number of fine bubbles are generated in seawater. be able to. When this foam is supplied, marine organisms such as shellfish, barnacles and slime can be scraped off, and adhesion of these marine organisms can be prevented.
なお、前記第１実施形態及び第２実施形態において、取水された海水中に、塩素系の殺菌剤を注入することも可能である。すなわち、従来の塩素処理と本発明の第１実施形態の海生物付着防止方法とを併用することができる。従来の塩素処理と併用すると、従来の塩素処理の殺菌効果と相俟って、海生物の付着を一層防止することができる。 In the first embodiment and the second embodiment, it is also possible to inject a chlorine-based disinfectant into the taken seawater. That is, the conventional chlorination treatment and the marine organism adhesion preventing method of the first embodiment of the present invention can be used in combination. When used in combination with conventional chlorination, it is possible to further prevent the attachment of marine organisms in combination with the sterilization effect of conventional chlorination.
まず、マイクロバブルによる窒素ガスと二酸化炭素ガスの注入率とｐＨの関係を調べた。ｐＨの測定は、センサー（自記式多項目水質計In‐Situ社TROLL9000）、（東亜DKK：電気伝導率・ｐＨ計 WM‐22EP）を用いた。図２に窒素と二酸化炭素の注入率とｐＨの関係を示す。窒素は、海水中に６．６％注入するとｐＨを僅かに低下させるに留まったが、二酸化炭素は、海水中に６．６％注入すると８．１４から５．９３まで低下した。 First, the relationship between the injection rate of nitrogen gas and carbon dioxide gas by microbubbles and pH was examined. For the measurement of pH, a sensor (self-recording multi-item water quality meter In-Situ TROLL9000), (Toa DKK: electric conductivity / pH meter WM-22EP) was used. FIG. 2 shows the relationship between the injection rate of nitrogen and carbon dioxide and pH. Nitrogen only slightly reduced the pH when injected at 6.6% into seawater, while carbon dioxide decreased from 8.14 to 5.93 when injected at 6.6% into seawater.
また、図３に示すように、窒素と二酸化炭素を注入した際には、マイクロバブルの生成状況に違いが認められることがわかった。二酸化炭素を注入した場合、窒素に比べて明らかに細かいマイクロバブルが生成した。なお、図３において、左側が窒素のマイクロバブル、右側が二酸化炭素のマイクロバブルであり、ガス量はいずれも2L／min、海水流量は30L／minである。 Moreover, as shown in FIG. 3, when nitrogen and carbon dioxide were inject | poured, it turned out that a difference is recognized in the production | generation condition of a microbubble. When carbon dioxide was injected, microbubbles that were clearly finer than nitrogen were generated. In FIG. 3, the left side is nitrogen microbubbles, the right side is carbon dioxide microbubbles, the gas amount is 2 L / min, and the seawater flow rate is 30 L / min.
窒素のマイクロバブルのガス注入率と付着防止率の関係を図４に示す。図中の四角印は湿重量による付着防止率、丸印は個体数による付着防止率を示す。曲線は、湿重量による付着防止率の近似曲線である。試験を行った窒素ガスの注入率７％以下の範囲では、付着防止率は最大でも８０％台であり、これ以上の効果は認めがたい。このため、窒素のマイクロバブルを適用するのであれば、３〜４割程度の付着を許容できる場所や設備において、注入率２〜３％の比較的少ないガス量で運用するのが特に好ましい。また、窒素ガスを０．１％注入した場合、海生物の付着防止率は約４％である。一方、窒素ガスを４％注入することで、海生物の付着防止率が約８０％であることが確認できた。これにより、実用的に海生物の付着を防止するためには、窒素ガスの注入率を０．１％〜４％の範囲とするのがよい。窒素ガスの注入率が０．１％未満であると、海生物の付着防止効果が十分に得られ難い。また、窒素ガスの注入率が４％を超えると、それ以上窒素ガスを注入することによる効果は少なく、さらには窒素ガスの注入量が多くなり、実用的ではない。 The relationship between the gas injection rate of nitrogen microbubbles and the adhesion prevention rate is shown in FIG. In the figure, the square marks indicate the adhesion prevention rate due to wet weight, and the circles indicate the adhesion prevention rate due to the number of individuals. The curve is an approximate curve of the adhesion prevention rate due to wet weight. In the range where the nitrogen gas injection rate is 7% or less, the adhesion prevention rate is in the 80% range at the maximum, and the effect beyond this is difficult to recognize. For this reason, if nitrogen microbubbles are applied, it is particularly preferable to use a relatively small amount of gas with an injection rate of 2 to 3% in a place or facility that allows about 30 to 40% of adhesion. Further, when 0.1% of nitrogen gas is injected, the marine organism adhesion prevention rate is about 4%. On the other hand, by injecting 4% nitrogen gas, it was confirmed that the marine organism adhesion prevention rate was about 80%. Thus, in order to practically prevent the attachment of marine organisms, the nitrogen gas injection rate is preferably in the range of 0.1% to 4%. If the injection rate of nitrogen gas is less than 0.1%, it is difficult to sufficiently obtain the effect of preventing the adhesion of marine organisms. Further, when the nitrogen gas injection rate exceeds 4%, the effect of injecting nitrogen gas further is small, and the amount of nitrogen gas injection increases, which is not practical.
窒素のマイクロバブル注入による付着防止効果として、参考のため付着物重量は図５に、付着生物数を図６に示す。付着物の湿重量は、窒素ガス注入率が５．７％のとき、対照区の付着量を１００％として付着率が１７．９％であり、注入率６．７％では付着率が１６．６％であった。付着生物数は、窒素ガス注入率が３．３％のとき付着率が２４．２％、注入率が５．７％のとき付着率は３３．１％、注入率が６．７％では付着率１４．７％となった。このように、一部に例外があるものの、窒素ガスの注入率と付着防止効果については概ね相関が認められた。 As an anti-adhesion effect by injecting nitrogen microbubbles, the adhering material weight is shown in FIG. 5 and the number of adhering organisms is shown in FIG. 6 for reference. The wet weight of the deposit is 17.9% when the nitrogen gas injection rate is 5.7% and the amount of deposit in the control group is 100%, and when the injection rate is 6.7%, the deposit rate is 16. It was 6%. The number of attached organisms is 24.2% when the nitrogen gas injection rate is 3.3%, 33.1% when the injection rate is 5.7%, and adheres when the injection rate is 6.7%. The rate was 14.7%. Thus, although there are some exceptions, a correlation was generally recognized between the nitrogen gas injection rate and the adhesion prevention effect.
二酸化炭素のマイクロバブルのガス注入率と付着防止率の関係を図７に示す。図中の丸印は個体数による付着防止率、三角印は湿重量による付着防止率を示す。さらに比較のため、四角印は窒素ガスの湿重量の付着防止率を示す。注入率が６．７％では、窒素のマイクロバブルによる湿重量の付着防止率が８３．４％であるのに対し、二酸化炭素では９５．４％となり、同じ注入率では二酸化炭素の方がより効果的であることがわかった。高い付着防止効果が要求されるプレート型熱交換器の付着防止法として、窒素のマイクロバブルよりも適しているといえる。また、二酸化炭素ガスを０．１％注入した場合、海生物の付着防止率が約４％である。一方、二酸化炭素ガスを４％注入することで、海生物の付着防止率が約９５％あることが確認できた。これにより、実用的に海生物の付着を防止するためには、二酸化炭素ガスの注入率を０．１％〜４％の範囲とするのがよい。二酸化炭素ガスの注入率が０．１％未満であると、海生物の付着防止効果が十分に得られ難い。また、二酸化炭素ガスの注入率が４％を超えると、それ以上二酸化炭素ガスを注入することによる効果は少なく、さらには、二酸化炭素ガスの注入量が多くなり、実用的ではない。 The relationship between the gas injection rate of carbon dioxide microbubbles and the adhesion prevention rate is shown in FIG. The circles in the figure indicate the adhesion prevention rate due to the number of individuals, and the triangles indicate the adhesion prevention rate due to wet weight. For further comparison, the square mark indicates the wet weight adhesion prevention rate of nitrogen gas. When the injection rate is 6.7%, the wet weight adhesion prevention rate due to nitrogen microbubbles is 83.4%, whereas carbon dioxide is 95.4%, and at the same injection rate, carbon dioxide is more It turns out to be effective. It can be said that it is more suitable than nitrogen microbubbles as an adhesion prevention method for plate heat exchangers that require a high adhesion prevention effect. In addition, when carbon dioxide gas is injected at 0.1%, the marine organism adhesion prevention rate is about 4%. On the other hand, by injecting 4% carbon dioxide gas, it was confirmed that the marine organism adhesion prevention rate was about 95%. Thereby, in order to practically prevent the attachment of marine organisms, the injection rate of carbon dioxide gas should be in the range of 0.1% to 4%. If the injection rate of carbon dioxide gas is less than 0.1%, it is difficult to sufficiently obtain the effect of preventing the adhesion of marine organisms. Moreover, when the injection rate of carbon dioxide gas exceeds 4%, the effect of injecting carbon dioxide gas further is small, and further, the amount of carbon dioxide gas injection increases, which is not practical.
二酸化炭素のマイクロバブル注入による付着防止効果として、参考のため付着物重量は図８に、付着生物数を図９に示す。二酸化炭素では、付着物重量と付着生物数とで共に、注入率と付着率とに負の相関が認められた。 As an anti-adhesion effect due to the injection of carbon dioxide microbubbles, the adhering substance weight is shown in FIG. 8 and the number of adhering organisms is shown in FIG. 9 for reference. In the case of carbon dioxide, a negative correlation was observed between the injection rate and the adhesion rate in both the weight of the deposit and the number of organisms.
次に、二酸化炭素注入による熱伝導率への影響確認試験を行った。図１０に熱伝達率影響確認装置を示す。この装置は、発電所復水器細管の汚れ係数を測定するためのもので、アルミ黄銅管の外面に熱伝対を取付けて、管の外側から電気式ヒーターで加熱し、通水した水の入口と出口との温度差から汚れ係数を測定して、熱貫流率を計算する。この装置の上流に、図１に示すようなマイクロバブル発生装置を設置し、二酸化炭素ガスのマイクロバブルを発生させる。 Next, a test for confirming the influence of carbon dioxide injection on thermal conductivity was performed. FIG. 10 shows a heat transfer coefficient influence confirmation device. This device is used to measure the coefficient of contamination of the condenser condenser of a power plant. A thermocouple is attached to the outer surface of an aluminum brass tube, heated by an electric heater from the outside of the tube, and the water passed through. The coefficient of fouling is measured from the temperature difference between the inlet and outlet and the heat transmissivity is calculated. A microbubble generator as shown in FIG. 1 is installed upstream of this device to generate carbon dioxide gas microbubbles.
熱貫流率の測定結果を図１１、及び表１に示す。熱貫流率は、３．１９７〜３．２９２kcal／m2h℃の範囲で、新管比は９８．７〜１０１．２％の範囲にあり、注入量に比例した影響はなかった。これにより、二酸化炭素のマイクロバブルによる熱伝達に及ぼす影響がないことがわかり、省エネルギー効果が期待できることがわかった。 The measurement results of the heat transmissivity are shown in FIG. The heat transmissibility was in the range of 3.197 to 3.292 kcal / m 2 h ° C., and the new tube ratio was in the range of 98.7 to 101.2%, and there was no effect proportional to the injection amount. As a result, it was found that there was no effect on heat transfer by the microbubbles of carbon dioxide, and it was found that an energy saving effect could be expected.
二酸化炭素の脱気試験の結果を図１２に示す。二酸化炭素をマイクロバブルで注入した直後のｐＨは直ちに５．３１まで下がり、この時点を試験開始とした。その後、室温で温度とｐＨのデータを記録した。途中、超音波洗浄機で脱気を試みたが、ｐＨは５．３１から５．６３に上昇した程度であった。図１２からもわかるように、ｐＨの値は温度が８．３２℃から２２℃まで上昇するに伴って上昇したが、１５分間でｐＨはわずか０．３２上がったのみで、回復したとはいえなかった。そこで、温度をヒーターにより加温し、天然の海水温度では起りえない４５℃まで加熱したが、図１２に示すように応答は見られなかった。これにより、二酸化炭素が一旦海水中に溶け込むと、海水から大気中へ出にくいことがわかった。 The results of the carbon dioxide degassing test are shown in FIG. The pH immediately after injecting carbon dioxide with microbubbles immediately dropped to 5.31, and this point was set as the start of the test. Thereafter, temperature and pH data were recorded at room temperature. In the middle, deaeration was attempted with an ultrasonic washer, but the pH was increased from 5.31 to 5.63. As can be seen from FIG. 12, the pH value increased as the temperature increased from 8.32 ° C. to 22 ° C., but the pH increased only 0.32 in 15 minutes, although it recovered. There wasn't. Then, the temperature was heated by a heater and heated to 45 ° C., which could not occur at the natural seawater temperature, but no response was seen as shown in FIG. As a result, it was found that once carbon dioxide was dissolved in seawater, it was difficult to get out of the seawater into the atmosphere.
次に、参考例として図１３に示す装置を用いて、空気、窒素ガス、二酸化炭素ガスのマイクロバブル注入量と、付着防止効果の関係を把握するために、海水を連続通水する試験を行った。揚水ポンプ（ツルミ製作所 50TM 2.75）１台を用いて、500Lのヘッドタンクに揚水し、不要な海水はオーバーフローさせ、ヘッドタンクの水位を一定に保った。ヘッドタンクには、独立した３つの系統毎に水中ポンプ（ツルミ製作所 50TM 2.75）を設置した。海水の流量は、面積式流量計とボールバルブによって調節し、樹脂製Y型ストレーナを経て、図１に示すようなマイクロバブル発生装置に給水し、海水と注入されたエアーまたはガスが試験水槽を通じて排水される。ストレーナとマイクロバブル発生装置の間に圧力計を設置し、マイクロバブルの生成条件を把握した。エアーまたはガスの流量は、0.2〜2L／minのガラス製ガス流量計とニードル式バルブを用いて調整した。マイクロバブル発生装置は、海水流量が30L／min、圧力が約0.08MPaの条件に適用可能な、オーラテック社インライン式マイクロバブル発生装置（タイプ１：PVC製）を使用した。また、試験水槽は、アクリル製の試験水槽（長さ300ｍｍ、幅210ｍｍ、厚さ50ｍｍ、容積約2L）を用いた。 Next, using the apparatus shown in FIG. 13 as a reference example, in order to grasp the relationship between the microbubble injection amount of air, nitrogen gas, and carbon dioxide gas and the adhesion prevention effect, a test of continuously passing seawater was conducted. It was. Using one pump (Tsurumi Seisakusho 50TM 2.75), water was pumped into a 500L head tank, and unnecessary seawater was overflowed to keep the head tank water level constant. A submersible pump (Tsurumi Seisakusho 50TM 2.75) was installed in the head tank for each of three independent systems. The flow rate of seawater is adjusted by an area-type flow meter and a ball valve, supplied to a microbubble generator as shown in Fig. 1 through a resin Y-strainer, and the injected air or gas passes through a test water tank. Drained. A pressure gauge was installed between the strainer and the microbubble generator, and the microbubble generation conditions were ascertained. The flow rate of air or gas was adjusted using a 0.2 to 2 L / min glass gas flow meter and a needle valve. The microbubble generator used was an Auratec in-line microbubble generator (type 1: made of PVC) applicable to conditions where the seawater flow rate was 30 L / min and the pressure was about 0.08 MPa. As the test water tank, an acrylic test water tank (length 300 mm, width 210 mm, thickness 50 mm, volume about 2 L) was used.
試験条件は、１ヶ月間を１期間とし、表２に示すように設定した。 Test conditions were set as shown in Table 2 with one month being one period.
海生物の付着状況は、実験終了後に試験水槽を回収し、ふたを外して目視観察を行った後、試験水槽のハコ側及びフタ側の写真撮影を行った。また、付着防止効果は、付着防止率（％）によって行った。なお、付着防止率（％）＝１００−（試験区の付着数÷対照区の付着数）×１００で付着防止率を計算した。 After the experiment was completed, the test water tank was collected, the lid was removed, and the seawater was attached to the sea creatures. After the visual observation, the octopus side and the lid side of the test water tank were photographed. Moreover, the adhesion prevention effect was performed by the adhesion prevention rate (%). In addition, the adhesion prevention rate was calculated by the adhesion prevention rate (%) = 100− (the number of adhesions in the test group / the number of adhesions in the control group) × 100.
図１４に第１期における試験水槽の海生物の付着状況、表３に第１期における付着量測定結果、図１５に対照区の海生物の付着数を１００％とした海生物の付着率を示す。これにより、エアーのマイクロバブルは、対照区の４５．７％、窒素のマイクロバブルは、３３．１％に付着量が抑えられ、窒素のマイクロバブルの有効性が確認できた。 Fig. 14 shows the state of attachment of marine organisms in the test tank in the first phase, Table 3 shows the results of measurement of the amount of adhesion in the first phase, and Fig. 15 shows the rate of attachment of marine organisms with the number of attached sea creatures in the control zone as 100%. Show. Thereby, the adhesion amount of air microbubbles was suppressed to 45.7% of the control group, and nitrogen microbubbles were suppressed to 33.1%, confirming the effectiveness of the nitrogen microbubbles.
図１６に第２期における試験水槽の海生物の付着状況、表４に第２期における付着量測定結果、図１７に対照区の海生物の付着数を１００％とした海生物の付着率を示す。これにより、窒素のマイクロバブルは、対照区の１４．７％、二酸化炭素のマイクロバブルは、０．４％に付着量が抑えられ、注入率が同じであれば、二酸化炭素のマイクロバブルによる効果が際立つ結果となった。 Fig. 16 shows the adhesion status of sea organisms in the test tank in the second phase, Table 4 shows the results of measurement of the amount of adhesion in the second phase, and Fig. 17 shows the marine organism adhesion rate when the number of sea creatures in the control zone is 100%. Show. As a result, if the amount of adhesion of the microbubbles of nitrogen is 14.7% of the control group and the amount of carbon dioxide microbubbles is 0.4% and the injection rate is the same, the effect of the carbon dioxide microbubbles Became a prominent result.
図１８に第３期における試験水槽の海生物の付着状況、表５に第３期における付着量測定結果、図１９に対照区の海生物の付着数を１００％とした海生物の付着率を示す。これにより、二酸化炭素のマイクロバブルの0.75L／min（海水に対する二酸化炭素ガス注入率2.5％）は対照区の１２．２％、二酸化炭素のマイクロバブルの1.5L／min（海水に対する二酸化炭素ガス注入率5.0％）は対照区の１０．５％に付着量が抑えられた。 Fig. 18 shows the state of attachment of marine organisms in the test tank in the third phase, Table 5 shows the results of measurement of the amount of adhesion in the third phase, and Fig. 19 shows the rate of attachment of marine organisms with the number of attached sea creatures in the control zone as 100%. Show. Thus, 0.75L / min of carbon dioxide microbubbles (carbon dioxide gas injection rate to seawater 2.5%) is 12.2% of control zone, and 1.5L / min of carbon dioxide microbubbles (carbon dioxide gas injection to seawater) The rate of 5.0%) was 10.5% of the control group, and the adhesion amount was suppressed.
１０ マイクロバブル発生装置
１１ ガス流路
１２ 海水流路
１３ 径方向部
１４ 軸方向部
１５ 混合部
DESCRIPTION OF SYMBOLS 10 Microbubble generator 11 Gas flow path 12 Seawater flow path 13 Radial direction part 14 Axial direction part 15 Mixing part
Claims (2)
海水との体積混合比である（二酸化炭素ガス／海水）を０．１〜４／１００として注入することにより、
海水中に、直径寸法が十〜数十μｍである二酸化炭素ガスのマイクロバブルを発生させ、このマイクロバブルにて二酸化炭素ガスを海水に溶解させて海水のｐＨを６．４〜８．１の範囲内とし、前記ｐＨ範囲内での海生物の付着防止が可能な海生物付着防止方法。 While decompressing the seawater taken from the seawater channel in the mixing section, carbon dioxide gas introduced from the gas channel to the decompressed seawater,
Is a volume mixing ratio of the seawater by entering Note as a (carbon dioxide / sea) of 0.1 to 4/100,
Carbon dioxide gas microbubbles having a diameter of 10 to several tens of μm are generated in seawater, and the carbon dioxide gas is dissolved in seawater with the microbubbles to adjust the pH of the seawater to 6.4 to 8.1. A marine organism adhesion prevention method capable of preventing adhesion of marine organisms within the pH range.
海水との体積混合比である（ガス／海水）を０．１〜４／１００として注入することにより、
海水中に、直径寸法が十〜数十μｍである前記ガスのマイクロバブルを発生させ、このマイクロバブルを海水に分散させて、マイクロバブルが海生物を擦り取ることにより海生物の付着防止が可能な海生物付着防止方法。 While decompressing the seawater taken from the seawater channel in the mixing section, the atmosphere introduced from the gas channel, or nitrogen gas to the decompressed seawater,
Is a volume mixing ratio of the seawater by entering Note as a (gas / seawater) to 0.1 to 4/100,
It is possible to prevent the attachment of marine organisms by generating microbubbles of the gas having a diameter of 10 to several tens of μm in seawater and dispersing the microbubbles in seawater, and the microbubbles scrape marine organisms. To prevent the adhesion of marine organisms.
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| JP2007105667A (en) * | 2005-10-14 | 2007-04-26 | Toshiba Corp | Cleaning method and operation method of plant |
| JP2008178789A (en) * | 2007-01-24 | 2008-08-07 | Toshiba Corp | Stain prevention device and method |
| JP2008280701A (en) * | 2007-05-09 | 2008-11-20 | Taiheiyo Cement Corp | Shell adhesion preventing device |
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2009
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20210013328A (en) * | 2012-03-03 | 2021-02-03 | 바덴-뷔르템베르크 스티프퉁 게게엠베하 | Gas-containing surface cover, arrangement, and use |
| KR102356570B1 (en) | 2012-03-03 | 2022-02-08 | 바덴-뷔르템베르크 스티프퉁 게게엠베하 | Gas-containing surface cover, arrangement, and use |
| US11584490B2 (en) | 2012-03-03 | 2023-02-21 | Baden-Württemberg Stiftung Ggmbh | Gas-containing surface cover, arrangement, and use |
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