TWI305765B - - Google Patents

Description

1305765, .-ξΓ 5 ilii Description of the Invention [Technical Field] The present invention relates to a treatment method and a treatment agent for simultaneously preventing metal corrosion and scale disorder of an open circulation cooling water system. [Prior Art]

A metal member provided in an open circulating cooling water system, such as a heat exchanger made of carbon steel copper or a steel alloy, and a reaction crucible or piping, which is corroded by contact with cooling water, is usually subjected to an anti-corrosion treatment by adding a chemical.

For example, in order to suppress corrosion of heat exchangers, reactors, and piping for carbon steel production, orthophosphate, hexametaphosphate, hydroxyethylidene diphosphonate, and phosphonic acid butane tricarboxylate have been added to cooling water. Phosphorus compounds. Further, a heavy metal salt such as a zinc salt or a dichromate may be added alone or in combination. However, the large-scale use of such phosphorus compounds or heavy metal salts, particularly the heavy use of heavy metal salts, has a significant impact on the environment due to the pollution of water quality, and (4) it is important to consider the treatment or drainage treatment and requires a large cost. On the other hand, 'for the corrosion protection of copper and copper alloy materials, although nitrogen-containing azole or phosphozinc-based drugs are mainly used, once a large amount of nitrogen-containing medicine or phosphorus is added to the closed water, the water area W When the faintness of the material is raised, the problem of environmental damage caused by red tides will be formed due to eutrophication. However, for water systems that do not contain scale inhibitors and have high calcium hardness and magnesium hardness, it is known that although carbon steel is initially corroded, it is difficult to further corrode after being corroded to a certain extent. It is believed that this is because the oxygen reduction reaction on the metal surface is activated by the corrosion reaction of 1305576, and hydroxide ions are generated, and the pH of the metal surface is increased. Therefore, scales such as carbonate fishing are deposited to cover the metal surface, so the oxygen supply amount is made. Reduce the 'results of corrosion inhibition is inhibited.

However, the adhesion of 水's scale to the metal surface can suppress the rancid reaction, but a large amount of scale adheres, and the efficiency is lowered due to heat transfer in the heat exchanger or the reactor, and the performance is poor. Further, in the piping system, the fluid passage is narrowed by the scale, and the discharge pressure of the pump rises, and in a significant case, various obstacles such as piping clogging may occur. In order to prevent the precipitation of calcium carbonate, it is effective to add a fluorinated compound such as phosphonic acid or polyphosphoric acid or a cis-succinic acid polymer. 'Adding these compounds to the open-circuit cooling water system generally prevents precipitation of calcium carbonate and eliminates scale and scale. The influence (see, for example, Japanese Laid-Open Patent Publication No. Hei 9-174092). However, when the water quality of the water system exceeds the limit of the prevention performance of the calcium carbonate precipitation by the compounds, the "acidification #5 rapidly crystallizes" to cause scale disorder. Further, in the case where a compound or a zinc salt is used, the precipitation of calcium phosphate or calcium zinc phosphate also causes an obstacle. Therefore, the water quality to which these compounds can be applied is limited, and the upper limit of the concentration multiple is also limited, and the use is limited. SUMMARY OF THE INVENTION An object of the present invention is to provide a cooling water treatment method capable of simultaneously preventing corrosion and scale disorder of carbon steel, copper, steel alloy and other metal equipment and machines in an open-flow type cooling water system without causing the above problems. And processing the agent. The method for treating cooling water according to the present invention is a method for treating cooling water which prevents scale damage while suppressing corrosion of the genus 1305576 of the cooling water system, characterized in that a calcium carbonate precipitation inhibitor and a carbonic acid and a dispersing agent are added to the cooling water. The calcium carbonate fine particles are dispersed in the cooling water to form an anti-corrosion film on the surface of the metal.

As described above, in order to suppress the corrosion of the metal, although the method of forming the calcium carbonate anti-corrosion film on the surface of the metal member is effective, the calcium ion and the carbonate ion in the water directly form the calcium carbonate anti-corrosion film, and since the reaction rate is slow, Further, since the concentration of the corrosion of the metal corrosion portion is sufficiently suppressed, the concentration is insufficient, so that it is not practical. Further, since the supply of the plasma to the metal surface depends on the diffusion in water, it is easily affected by the flow velocity or concentration in the system, and it is difficult to stably and reliably generate the film. In the present month, the carbonic acid which acts on the rotted portion of the metal can be present in the cooling water towel in the form of (4) dispersed micro-(4), and the supply amount is increased to the core portion, so that the calcium carbonate anti-corrosion film is stably and reliably generated in the early stage. On the other hand, by increasing the dispersibility thereof, it is possible to prevent excessive adhesion of scale and prevent scale. In other words, in order to form and disperse the fine calcium carbonate in the present invention, "D" and calcium carbonate precipitation inhibitor are used. To prevent the calcium carbonate from escaping; and the carbon_dispersion m is such that the calcium carbonate generated in the first stage exceeds the limit of the precipitation prevention performance of the carbon-precipitating agent is not coarsened. Disperse within a certain range of particle sizes. "...~Knife add 1~100ml of water to your crotch. Precipitant and carbon_dispersant, so that the carbon (tetra) particles are dispersed in grams/liter, so that the calcium carbonate dissolved in the cooling water is saturated.

The number of 1305765 reaches 1.2 to 3.5. The calcium carbonate precipitation inhibitor used in the present invention is preferably selected from the following (1) phosphonic acid compound, the following (2) carboxylic acid polymer, and the following (3) carboxylic acid copolymer; 〆 or more than two substances. (1) Hydroxyethylenedicarboxylic acid, 2-phosphonic butane d, 2,4-tricarboxylic acid, aminotrimethylenephosphonic acid, phosphinylbutane-I, 2, 3, 4 - at least one of four retinoids and phosphonic acid fumaric acid, (2) polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, polyacrylate, polymethacrylate , at least one of poly maleate and polyitaconate, (3) containing more than 50 mol% selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid and salts thereof One or two or more kinds of carboxylic acid components in the group, and one or two or more kinds of unsaturated groups selected from the group consisting of C4 to C10 olefins, styrene, and dicyclopentadiene a copolymer of a hydrocarbon component. Further, the calcium carbonate dispersing agent used in the present invention is preferably one or more selected from the following (4) carboxylic acid copolymer and the following (5) nonionic polymer. 30 mol% or more of one or more carboxylic acid components selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid, and the like, and 5 mol% or more from vinyl sulfonic acid One or more sulfonic acid group-containing unsaturated groups selected from the group consisting of allyl acid, styrene-isolated acid, isopropanyl acid, 3-allyloxy-2_hydroxypropanesulfonic acid, and the like a copolymer of a hydrocarbon component, 6 1305765 (5) at least one of a polyacrylamide, a polyvinyl alcohol, a polyethylene glycol, an A-propylene glycol, and an ethylene glycol-propylene glycol block copolymer. In the present invention, For the corrosion and scale generation, carbonic acid particles are used. For this reason, for example, it is preferable to use the following method (〇 or (U) ^ to form and disperse particles in cooling water. Jun (i) Adding calcium salt from the cooling water , * Salt and carbonate

a method in which one or two or more selected from the group consisting of a salt and an alkali metal cerium oxide is brought into contact with air to precipitate and disperse the calcium carbonate particles, and (ii) the temperature of the cooling water is raised. A method of precipitating and dispersing calcium carbonate particles. The treatment agent for cooling water of the present invention contains 5 to 95% by weight of one selected from the group consisting of the (1) phosphonic acid compound, the above (2) tannic acid polymer, and the above (3) carboxylic acid copolymer. Two or more kinds of calcium carbonate precipitation inhibitors, and 5 to 95% by weight of the above (4) citric acid-based copolymer and the above (5, one or two or more kinds of carbonic acid dance dispersing agents selected from nonionic polymers are available In the method for treating cooling water according to the present invention, the cooling water treatment method and the treatment agent of the present invention are used in the surface of the metal in the water system, and the early stable formation does not cause scale obstacles, but is sufficient. The calcium carbonate anti-corrosion film of an appropriate thickness which exhibits an anti-corrosion effect can surely prevent scale damage while suppressing corrosion of the metal. [Embodiment] Hereinafter, a method and a treatment agent for cooling water according to the present invention will be described in detail. In the cooling water treatment method, a calcium carbonate precipitation inhibitor and a calcium carbonate dispersing agent are added to the cooling water to disperse the calcium carbonate fine particles in the cooling water to make the metal table in the water system An anti-corrosion film is formed on the surface. As the calcium carbonate precipitation inhibitor added to the cooling water, a material used as a calcium carbonate scale inhibitor in the past may be used, but preferably, the following (1) phosphonic acid system is used. One or two or more selected from the group consisting of the compound, the following (2) carboxylic acid polymer, and the following (3) carboxylic acid copolymer.

(1) Hydroxyethylenedicarboxylic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, aminotrimethylenephosphonic acid, 1-phosphonic acid butane-1, 2, 3 , at least one of 4-tetracarboxylic acid and phosphonic acid counter-succinic acid, (2) polyacrylic acid, polymethacrylic acid, polymaleic acid, polyitaconic acid, polyacrylate, polymethyl At least one of an acrylate, a polymaleate, and a polyitaconate. The molecular weight of the carboxylic acid polymer is preferably from about 500 to 5,000. (3) one or more selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid and the like, containing 40 mol% or more, preferably 50 to 90 mol% a carboxylic acid component, and 5 mol% or more, preferably 10 to 50 mol% of a C4 to C10 olefin (e.g., isobutylene, butylene, isoprene, etc.), styrene, and dicyclopentadiene. A copolymer of one or more unsaturated hydrocarbon components selected from the group consisting of saturated hydrocarbon components. The molecular weight of the carboxylic acid copolymer is preferably from about 1,000 to 20,000. As the calcium carbonate dispersing agent, it is preferable to use a substance having such a functional group. When the calcium carbonate is adsorbed by a carboxyl group, a hydrophobic group such as a sulfonyl group or a hydrophobic group such as an ether group can be oriented toward the outside. Prevent the proximity between particles;

1305765 The calcium carbonate dispersing agent may, for example, be one or two or more selected from the group consisting of the carboxylic acid copolymer (4) and the following (5) nonionic polymer. (4) one or more selected from the group consisting of acrylic acid, mercaptoacrylic acid, maleic acid, itaconic acid, and the like, containing 30 mol% or more, preferably 5 〇 to 90 mol% The carboxylic acid component, and more than 5 mol%, preferably 10 to 50 mol% of the vinyl sulfonic acid, allyl sulfonic acid, styrene sulfonic acid, isoprene sulfonic acid, 3-allyl A copolymer of one or two or more kinds of unsaturated hydrocarbon components containing a sulfonic acid group selected from the group consisting of oxy-2-hydroxypropanesulfonic acid and the like. The molecular weight of the carboxylic acid copolymer is preferably from about 1 000 to about 20,000. (5) At least one of polypropylene decylamine, polyvinyl alcohol, polyethylene glycol, polypropylene glycol, and ethylene glycol-propylene-alcohol block copolymer. The molecular weight of the nonionic copolymers is preferably from about 5,000 to about 100,000. The addition amount of the calcium carbonate precipitation inhibitor and the calcium carbonate dispersing agent in the cooling water may be sufficient as long as the amount of the agent is sufficient to obtain a sufficient effect, depending on the type of the agent to be used, the quality of the cooling water of the treated article, and the kind of the metal of the corrosion-resistant member. The difference is generally 1 to 100 mg/liter, preferably 5 to 50 mg/liter, and the total amount of the calcium carbonate precipitation inhibitor and the calcium carbonate dispersant is about 10 to 10 mg/liter. When the amount of addition of the calcium carbonate precipitation inhibitor and the calcium carbonate dispersant is too small, a sufficient effect of addition cannot be obtained, and if it is too large, it is uneconomical, and the formation of carbonic acid particles is often slowed down. In addition, particularly in the case of compound filling, it is not preferable due to the problem of precipitation of acid-forming and drainage treatment. The necessary dispersing amount of the cerium carbonate microparticles dispersed in the cooling water in the present invention varies depending on the kind of the metal of the cooling anti-corrosion article, the water quality of the cooling water of the treated article, and the water temperature, and is generally about 1 to 1000 mg/liter to 5 to 100 mg. / 1305765 liters is better. When the amount of calcium carbonate particles dispersed in the cooling water is too small, sufficient corrosion resistance cannot be obtained, and when it is too large, there is a concern that scale is caused.

In addition, 'the particle size of the carbonized carbon dioxide dispersed in the cooling water is larger than j 〇 micron' or less than 0 · 0 1 micron, which does not contribute to the formation of the anti-corrosion film, and the particle size is below 10 μm, especially 00 b 10 μm of carbonic acid. The calcium microparticles preferably contain from 1 to 1000 mg/l, especially from 5 to 1 mg/l in water, but may also contain calcium carbate having a particle size of less than 0.01 micron or more than 10 micrometers in water. By using a calcium carbonate precipitation inhibitor and a calcium carbonate dispersing agent together, the carbonic acid angular fine particles can be formed. In the present invention, in order to prevent the scale corrosion, a sufficient amount of calcium carbonate particles to inhibit metal corrosion must be treated. The cooling water of the article maintains supersaturated water of calcium carbonate. Therefore, the hardness, the alkalinity, and the pH of the cooling water should be set to a certain value or more depending on the water temperature. The higher the degree of supersaturation of carbonic acid in the cooling water, the more the amount of calcium carbonate is precipitated, and the amount of the calcium silicate dispersing agent used to disperse the carbonic acid is increased, so it should be adjusted to the economic range. In the case where the hardness of the calcium carbonate is too high, the hardness of the carbonic acid fishing can be adjusted to an appropriate range by using a softening agent. On the other hand, when the supersaturation is too low, the precipitation amount of calcium carbonate is insufficient, and sufficient anti-button effect is often not obtained. The supersaturation of the cooling water is preferably about 1.2 to 3.5 in terms of saturation index. In order to disperse a predetermined amount of the carbonated fishing particles by setting the cooling water to the supersaturation, it is possible to add calcium carbonate fine particles obtained by pulverizing the calcium carbonate coarse particles by a pulverizer such as a cyclone grinder to the cooling water, and to oxidize the particles. Calcium carbonate fine particles formed by contact with high-temperature carbon dioxide gas after being pulverized into fine particles, or carbonic acid-based fine particles having an average particle diameter of about 1 to 5 μm, but preferably β 10 1305765 A method of cooling calcium carbonate particles chemically precipitated in water is advantageous. (i) adding one or more kinds of gasification fishing in the cooling water, acidification, about hydrogenation, etc., and one or more hydrogencarbonates such as sodium bicarbonate, potassium carbonate, lithium hydrogencarbonate, etc. A carbonate such as sodium, potassium carbonate or lithium acid sulphate, and a metal hydroxide such as sodium hydroxide, potassium hydroxide or hydroxide are brought into contact with air in a cooling tower to precipitate and disperse the calcium carbonate.

(ii) The temperature of the cooling water is raised by the heat exchanger to lower the solubility of the carbonic acid fishing, and the calcium carbonate fine particles are precipitated and dispersed. In the cooling water treatment method of the present invention, a chemical agent used in usual water treatment other than the addition of a calcium carbonate precipitation inhibitor and a calcium carbonate dispersing agent may be used in combination. For example, when a copper material is contained in the water system, if a nitrogen-based derivative such as benzotriazole or tolyltriazole is used in combination, the prevention of the copper material can be improved. Further, it is also possible to use a sterilizing agent such as a sub-acid soda. The agent for treating cooling water according to the present invention includes the above-mentioned acid-repellent-precipitating agent (four) agent and a carbonic acid-based dispersing agent according to the present invention. In the medicinal agent of the present invention, the calcium carbonate precipitation inhibitor and the calcium carbonate dispersing agent are usually contained in an amount of 5 to 95% by weight, respectively, and preferably 20 to 80% by weight. In the treatment agent of the present invention, the calcium carbonate precipitation inhibitor and the cesium carbonate dispersant may be supplied separately by mixing the oxic acid precipitation inhibitor and the carbonic acid mother dispersant in advance. Further, various embodiments other than the calcium carbonate precipitation inhibitor and the calcium carbonate dispersing agent may be further included, and the present invention will be more specifically described by way of the following examples and comparative examples. 11 1305765 Examples 1 to 7 and Comparative Examples 1 to 1 4 The intermittent cooling water system evaluation shown schematically in Fig. 1 was carried out, and the corrosion prevention effect and the scale prevention effect test in the examples and the comparative examples were carried out. The water quality of the industrial water used in the test is shown in Table 1 below. The calcium carbonate precipitation inhibitor and the calcium carbonate dispersing agent used are as shown in Table 2 below.

The test results are adjusted and shown. Table 1 Water quality of industrial water pH 7.4 Conductivity (mS/m) 33 验 Degree of inspection (mg/Las CaC〇3) 80 Total hardness (mg/LasCaC〇3) 120 Approximate hardness (mg/Las CaC〇3) 80 II Cerium oxide (mg/L) 25 Table 2 Calcium carbonate precipitation inhibitor A Maleic acid/acrylic acid/styrene copolymer (Morby 60: 25: 15, molecular weight 10000) B Maleic acid/isobutylene copolymerization (Mole ratio 1:1, molecular weight 14000) C Polyacrylic acid (molecular weight 2000) D Polymaleic acid (molecular weight 600) E Aminotrimethylenephosphonic acid F hydroxyethylidenephosphonic acid G 2-phosphonic acid Butadiene-1,2,4-tricarboxylic acid 12 1305765 Calcium carbonate dispersant a Polyvinyl alcohol (molecular weight 20000) b Polyethylene glycol (molecular weight 12000) c Acrylic acid/vinyl sulfonic acid copolymer (Morby 75 : , Gongfu + d Acrylic acid / allyl sulfonic acid copolymer (Mo Erbi 7 〇: 30, work in w, e acrylic / styrene sulfonic acid copolymer (Mo Erbi 8 〇: 20, Gong; County βΛΛΛ, f Acrylic acid/3-propoxy-2-hydroxypropanesulfonic acid copolymer (Morbi 8〇: 八子量3000) ^ g Acrylic acid/hydroxy methacrylate/isoprene sulfonic acid Composition (molar ratio of 70: 10: 20, molecular weight 13,000)

In the evaluation test apparatus of Fig. 1, the circulating cooling water is supplied from the cooling tower 1 to the heat exchanger 3 by the circulation pipe 2 having the pump P1, and the return water is returned to the cooling tower 1 through the pipe 4. 5 is the introduction pipe for the makeup water. 6 is an introduction pipe for the sodium hypochlorite aqueous solution, 7 is an introduction pipe for the chemicals shown in Table 3, and 8 is a flow pipe, and has pumps P2, P3, P4, and p5, respectively. The heat exchanger 3 is a steam heating tube water-passing heat exchanger having three carbon steel tubes having an outer diameter of 19 mm, a length of 1,500 mm, and a thickness of 23 mm, and a corrosion meter shown in the figure is mounted on the tube. 9 is a piping pipe with a valve 9a. The operating conditions of this evaluation test apparatus are as follows. [Operating conditions] Water retention: 380 liters per minute in circulating water. (including cooling tower circulating water in heat exchanger piping) 13 1305765 Flowing water volume: 4 · 5 to 9.5 liters / hour (by concentration factor) Make-up water: Industrial water supply water quantity: 2 4~2 9 liters / hour (in terms of concentration multiple) Flow rate: 0.3 m / sec Concentration multiple: as shown in Table 3, heat exchanger inlet water temperature: 30 ° C Heater outlet water temperature: 50 ° C (steam heating)

Water temperature difference Δ t : 20°C Sodium gas addition amount: continuous injection to make the residual chlorine concentration in the cooling water reach 0.3~0.5 mg/L. Additive amount: Add the concentration shown in Table 3 to add the concentration shown in Table 3. . The above operation was carried out for 30 days. The primary/day decay rate (carbon steel) was measured by a corrosion meter. The calcium hardness analysis in the cooling water was carried out once a week, and the cooling water was filtered using a 〇 i micrometer Millipore filter, and the calcium hardness of the filtrate was determined by a titration method. Further, the calcium hardness of the captured portion of the screening program was measured by atomic absorption after adding hydrochloric acid to boil. W ^ ^ I. Μ τ was taken out of the test tube, and after being dried, it was cut every 20 cm to evaluate the attached matter and the corrosion hole. The attachment of the test tube was removed with a metal brush, and the adhesion speed of the scale was calculated from the dry weight and the tube area. Further, the test tube after the attachment was removed was pickled with an acid-retaining agent hydrochloric acid to remove the rot product. The depth of the test hole was measured by a depth gauge to determine the maximum value. In the heat exchanger, the calcium hardness of the filtrate and the calcium hardness of the filtered trap portion 14

1305765 The corrosion rate of the pipe, the depth of the corrosion hole and the scale adhesion rate are shown. The corrosion rate, the calcium hardness of the filtrate, and the measured value of the filtration capture: are respectively used as the average value of the period. Further, in Table 3, the difference between the calcium hardness of the filtrate and the partial calcium hardness is subtracted from the supply water (the value of the industrial calcium hardness multiplied by the concentration factor), and is dissolved as an indicator of the scale tendency. The saturation index of carbonic acid in the cooling water is as shown in the table and the amount of carbon dispersed in the cooling water is 0.1 to 10 μm, and the hardness of the calcium captured by the 0.1 μm filter is calculated as 〇 liter. Filter capture 〇 3, calcium acid particles 3 〇 mg /

15 1305765 Table 3 Example Example Comparative Example Cooling Water Calcium Carbonate Calcium Carbonate Cooling Water Calcium Cooling Evaluation Effect Water Quality Inhibitor Dispersant Hardness (mg/Las CaC03 in Water) Solvent Concentrate Concentrated 0.1 0.1 Scale Carbon Corrosion Surname of scale with degree of micron-micronized calcium sulphate speed hole deep speed (m (fluid filtration to *4 fullness (m degree (mg/cg mg / capture and finger dd) (m m2 / month) / L) L) number ml month) 1 industrial A 30 a 40 210 30 0 1.44 2.3 0.17 4.7 2 water 3 times concentrated B 5 b 20 230 10 0 1.57 3.4 0.13 2.8 3 shrinkage C 10 c 5 230 5 5 1.57 3.9 0.15 3.4 4 Industrial D 20 d 20 300 15 5 1.96 2.7 0.21 9.8 5 Water 4 times concentrated E 6 e 20 315 5 0 2.03 2.3 0.17 3.6 6 Shrinkage F 6 f 15 310 5 5 2.01 1.8 0.16 2.1 7 Industrial water 5 times concentrated Water G 14 g 25 380 15 5 2.31 1.0 0.20 5.5 1 Industrial A 80 213 0 27 1.45 16.0 0.38 4.3 2 Water 3 times concentrated B 20 240 0 0 1.63 4.0 0.25 5.2 3 Shrinkage C 20 230 5*1 5 1.60 8.9 0.47 37.6 4 Industrial D 40 310 0 10 2 .01 7.2 0.37 38.0'3 5 Water 4 times concentrated E 30 316 0 4 2.04 1.8 0.30 24.3*2 6 Shrinkage F 20 310 0 10 2.01 1.6 0.28 27.1*2 7 Industrial water 5 times concentrated water G 40 376 0 24 2.30 1.9 0.26 11.7*3 8 Industrial a 80 155 0 85 0.99 60.5 0.44 38.0 9 Water 3 times thick b 40 160 0 80 1.04 43.2 0.52 27.6 1 0 Shrinkage c 20 200 0 40 1.37 13.8 0.34 6.0 1 Industrial d 40 250 0 70 1.69 14.6 0.38 4.2 1 Water 4 times concentrated 1 2 Shrinkage e 30 180 0 140 1.21 28.0 0.42 15.6 1 3 f 30 250 0 70 1.69 5.9 0.36 1.4 1 Industrial g 40 230 0 170 1.57 8.3 0.32 2.3 4 Water 5 times concentrated water

*1 Filter catch is a gel of polymer and calcium ions *2 The main component of the attachment is calcium phosphate *3 The main component of the attachment is magnesium citrate * 4 water supply (industrial water) calcium hardness X concentration Multiple 1 (calcium hardness of the filtrate + filtered to capture calcium hardness) Table 3 shows that the use of the present invention can simultaneously prevent the rot and scale barrier of the gold 16 1305765 genus in the cooling water system. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a system diagram showing an outline of an intermittent cooling water system evaluation test apparatus used in Examples and Comparative Examples. [Main component symbol description]

1 Cooling tower 2 Circulating piping 3 Heat exchanger 4 Piping 5 Make-up water introduction piping 6-time sodium chlorate aqueous solution introduction piping 7 Chemical introduction piping 8 Flow piping 9 Pipe piping 9a Valve P1-P5 pump

17

Claims (1)

1305765 ___--*··*-"jf (〆)!£本丨拾,申请专利范围:: 1. A cooling water treatment method that prevents scale damage while suppressing the corrosion of the cooling water system. a calcium carbonate precipitation inhibitor and a calcium carbonate dispersing agent added to the cooling water to disperse calcium carbonate particles in the cooling water to form an anti-corrosion film on the metal surface; Wherein the 'ravine acid-based precipitation inhibitor is one selected from the group consisting of the following (丨) phosphonic acid-based compound, the following (2) phthalic acid polymer, and the following (3) carboxylic acid-based copolymer or Two or more kinds: (1) hydroxyethylidene diphosphonic acid, 2-phosphonic acid butane 丨, 2,4 • tricarboxylic acid, aminotrimethylene phosphonic acid, 1-phosphonic acid butyl sulfonium At least one of -i, 2,3,4-tetracarboxylic acid and phosphonic acid fumaric acid, to τ®-enic acid, polymaleic acid, polyitaconic acid, polycapping acid salt, At least one of polymethyl propyl acrylate, poly cis succinate, and polyitaconate, (3) one or more selected from the group consisting of acrylic acid, mercapto acrylic acid, maleic acid, itaconic acid, and the like, containing 40 mol% or more of whitish ± bis & a few acid components, and a copolymer of 5 mol% or more selected from the group consisting of C4 to C-diolefins, styrene, and dicyclopentadiene, and a mixture of 4 and 4 kinds of saturated hydrocarbon components; The calcium dispersing agent is one or more selected from the group consisting of the following (4) carboxylic acid copolymer spear nonionic polymer. The following (5) (4) contains 30 mol% or more of acrylic acid. a group consisting of τ 4^ propylene-diethyl phthalic acid, itaconic acid, and the like, a ton-selected species or two carboxylic acid components of 1 1305765 or more, and 5 mol% or more of ethylene. One or more selected from the group consisting of a group consisting of a base acid, a dilute sulfonic acid, a styrene sulfonic acid, an isoprene sulfonic acid, a 3- allyl oxy-methane acid, and a salt thereof. a copolymer containing an acid group-containing unsaturated hydrocarbon component' (5) a polypropylene-stranded amine, a polyvinyl alcohol, a polyethylene glycol, a polypropylene-alcohol glycol-propylene glycol block At least one of the polymers. 2. In the cooling water treatment method of claim 1, the Lishi is added to the cooling water by adding 1 to 100 mg/liter of calcium carbonate precipitation inhibitor calcium carbonate dispersing agent, so that the calcium carbonate particles are 5 When the concentration of ~100 mg/L is dispersed, the saturation index of the calcium carbonate dissolved in the cooling water is 1 2 to 3 5 3. The cooling water treatment method of the first or second aspect of the patent application is as follows. One or two or more substances selected from the group consisting of calcium salts, hydrogencarbonates, carbonates, and metal hydroxides are added to the cooling water, and the calcium carbonate fine particles are precipitated and dispersed by bringing them into contact with air. 4. The cooling water treatment method according to claim 1 or 2, wherein the water particles of the cooling water are raised to precipitate and disperse the particles. The method of treating the cooling water according to the third aspect of the patent application, wherein the calcium carbonate particles are precipitated and dispersed by raising the temperature of the water of the cooling water. Borrowing 1305576. The cooling water treatment agent is characterized in that it contains $~weight: from the following (1) phosphonic acid compound, the following (2) carboxylic acid polymer, and the lower <(3) carboxylic acid system One or two or more kinds of anti-calcium precipitation inhibitors selected from the group consisting of copolymers, and 5 to 9% by weight of the following (4) carboxylic acid-based copolymer and the following (5) nonionic One or more calcium carbonate dispersants selected from the group consisting of polymers: (1) Hydroxyethylenedicarboxylic acid, 2-phosphonobutane-1,2,4-tricarboxylic acid, aminotrimethylenephosphonic acid, 1-phosphonic acid butyrate _1,2,3 , at least one of 4-tetracarboxylic acid and tartaric fumaric acid, (2) polyacrylic acid, polymethacrylic acid 'polymaleic acid, polyitaconic acid, polyacrylic acid salt, polymethyl At least one of a acrylate, a polymaleate, and a polyitaconate, (3) containing more than 40 mol% of acrylic acid, methacrylic acid, maleic acid, itaconic acid, and One or two or more kinds of carboxylic acid components selected from the group consisting of salt groups, 5 mol% or more of one selected from the group consisting of C4 to C10 bond olefins, present ethylene and dicyclopentadiene a copolymer of two or more unsaturated tobacco components (4) containing 30 mol% or more of a group selected from the group consisting of acrylic acid, methacrylic acid, maleic acid, itaconic acid, and the like Or two or more kinds of carboxylic acid components, more than 5 mol% of vinyl sulfonic acid, dipropyl propyl acid, styrene sulfonic acid, isoprene sulfonic acid, 3-allyloxy a copolymer of one or two or more kinds of unsaturated hydrocarbon components containing a repeating acid group selected from the group consisting of salts (5) polyacrylamide, polyvinyl alcohol, polyethylene glycol, polyacrylonitrile And at least one of 1305576 ethylene glycol-propylene glycol block copolymer. 4