JP3260942B2 - How to prevent marine organisms from sticking - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing marine organisms from adhering to marine structures such as introduction paths, water pipes, plants and the like of systems using seawater as cooling water.

[0002]

2. Description of the Related Art As is well known, in thermal power plants, pig iron and steel mills, petroleum refineries, petrochemicals, and chemical factories that use seawater, marine organisms living in seawater adhere to the cooling water system. Then its function is reduced. Examples of the marine organism include shellfish such as mussels, barnacles and oysters, attached organisms such as worms and bryozoans, and alga such as laver, diatoms, algae, and slimes. As these marine organisms grow in headraces, headraces, or plants, they can narrow the pipes and cause a decrease in seawater flow, drop off and block tubes in the heat exchanger, Corrosion of tubes, water pipes, etc. Therefore, after a certain period of operation, the operation has to be stopped and cleaned by a physical method to remove the marine organisms and clean the corroded inner wall as described above.

[0003]

However, the above-mentioned cleaning requires cessation of operation, and the cleaning takes time and effort, and the marine life grows in a short period of time. Had to clean. In addition, since the grown shellfish and the like become a large amount of waste, disposal after removal has also become a problem.

[0004] In recent years, aliphatic amines, β-
Ethylene oxide adduct of hydroxy-substituted aliphatic amine, ethylene oxide adduct of N-monosubstituted propylene diamine, aliphatic oxypropylene amine, aliphatic ethylene diamine, secondary aliphatic amine, tertiary aliphatic amine, quaternary It has been proposed to add a trace amount of a water-soluble amine such as an ammonium salt.

However, even if the above water-soluble amines are used as such or diluted with water, methyl alcohol, or ethyl alcohol, and injected intermittently or continuously into the seawater line, marine organisms such as mussels, barnacles, worms, bryozoans, sea squirts, etc.
It temporarily stops living functions and waits for the passage of the poison, or ingesting the poison does not kill it but only suppresses growth. In addition, when these water-soluble amines are injected 5 to 10 times the conventional addition amount, marine organisms can be killed and adhesion to marine structures can be prevented. There is a problem that other living organisms such as fish, crustaceans, mollusks, and shellfish are also killed, and furthermore, the processing cost is increased, which is economically disadvantageous. Furthermore, in addition to these water-soluble amines, chlorine such as sodium hypochlorite is also injected. However, injection of these chlorines causes trihalomethane to be generated in seawater, and is currently being used in society. It has become a problem.

On the other hand, as described in, for example, JP-A-3-186694, a method has been proposed in which ozone is injected into seawater as an active ingredient to prevent marine organisms from adhering, and relatively good results have been obtained. But not enough.

[0007]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above, and is characterized by adding ozone and a surfactant to seawater as active ingredients in order to exert the effect of ozone more strongly. The present invention relates to a method for preventing marine organisms from adhering.

Among the surfactants used in the present invention, nonionic surfactants are better than other ionic surfactants such as anionic, cationic and amphoteric surfactants. Oxyethylene alkyl ether, polyoxyethylene alkyl phenol ether,
Examples include polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, pronic tetronic, polyoxyethylene fatty acid amides, polyoxyethylene fatty acid amides, polyoxyethylene alkylamines, polyoxyethylene glyceryl mono fatty acid esters, and the like.

The ozone in the present invention is added (injected) so that the dissolved amount thereof is 0.1 to 8 ppm in seawater.
The injection method may be either continuous injection or intermittent injection. On the other hand, the addition (injection) location of the surfactant is before the ozone injection location and before the seawater flow, and the injection amount is 20 to 500 pp
m. Further, the surfactant is injected continuously in the case of continuous ozone injection, may be continuously injected in the case of intermittent ozone injection, or may be intermittent injection in accordance with the ozone injection time.

The method for attaching marine organisms according to the present invention comprises:
As described above, by adding ozone and a surfactant to seawater, the surfactant lowers the interfacial tension of seawater, and the ozone water or ozone-containing seawater penetrates marine organisms.
Since the contact is facilitated, the ozone sterilization, algicidal, and shell-killing effects can be improved. In addition, the addition of the surfactant reduces the rate of self-decomposition of ozone and weakens the amount of dissolved ozone, so that the ozone existence time can be extended. Furthermore, the amount of dissolved ozone can be increased by adding a surfactant, and the effect of ozone can be further enhanced. As described above, due to the above-described combined effect, the suppression of adhesion of marine organisms is significantly improved as compared with the case of using ozone alone.

[0011]

【Example】

Examples 1-3, Comparative Examples 1-5; 100 made of polyvinyl chloride
A test plant was prepared in which a cedar board (test piece) was placed in a water channel having a size of 100 mm square and a length of 2.5 m, and seawater was passed through. Using this test plant, the seawater flow rate is 7.5m ³
Examples 1 to 3 in which ozone generated from an ozone generator was added to seawater at a flow rate of 0.35 m / hr at a flow rate of 0.35 m / hr, and a surfactant used in combination with ozone was injected into seawater with a metering pump. The amount of marine organisms deposited for 6 months was compared with the blank (Comparative Example 1). In addition, the same test was performed for Comparative Examples 2 to 4 in which only ozone was added and Comparative Example 5 in which only a surfactant was added. The results are shown in Table 1 together with the processing conditions.

[0012]

[Table 1]

[0013]

As described above, the method for suppressing the adhesion of marine organisms according to the present invention can suppress the adhesion of marine organisms only by injecting ozone and a surfactant into the seawater cooling water system.

Therefore, the removal of attached marine organisms can be achieved without stopping the operation of the marine structure, thereby enabling continuous operation and having a time and economic advantage over the conventional cleaning method. It will be very large.

Further, the addition of ozone to seawater can be achieved simply by installing an ozone generator, and the addition of surfactant to seawater can be achieved by simply installing a metering pump. Are practically very valuable since they require virtually no workers.

Furthermore, according to the present invention, since marine organisms, particularly shellfish, do not grow, there is no problem of disposal treatment unlike the conventional cleaning method.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ identification code FI C02F 1/50 540 C02F 1/50 540A 1/78 1/78 (58) Investigated field (Int.Cl. ⁷ , DB name) C02F 1/00 C02F 1/50 C02F 1/78

Claims (1)

(57) [Claims] 1. A method for preventing marine organisms from adhering, comprising adding ozone and a surfactant as active ingredients to seawater.