UA16087U - A method for protection of water rotation systems from corrosion and salts deposition - Google Patents

Abstract

A method for protection of water rotation systems from corrosion and salts deposition by introduction to water of salts deposition inhibitors and corrosion inhibitor F1 includes sodium tripolyphosphate, polyphosphoric acid, sodium acetate and water, at that as salts deposition inhibitors used are sodium salt of vinyl acetate copolymer and maleic anhydride of sodium salt of carboxymethylcellulose and oxyethylenephosphonic acid or sodium salt thereof.

Description

Description of the invention

The proposed useful model refers to the protection of technological equipment from corrosion and 2 salt deposits and can be used in the chemical, petrochemical, energy industries for the treatment of water used for cooling heat exchange equipment, as well as in closed circulating water supply systems for the treatment of circulating water.

There is a known method of protection against corrosion and salt deposition, which includes introducing a corrosion and salt deposition inhibitor into the water, containing oxyethylidene diphosphonic acid (OEDF), zinc salt and water. 70 The disadvantage of this method is that the presence of zinc salts in the composition reduces the effect of inhibiting salt deposition with a very weak effect of inhibiting corrosion. In addition, it is possible to reduce the environmental friendliness of water circulation systems when using this inhibitor due to the migration of zinc into the atmosphere during spray removal, and into reservoirs during blowdowns.

The method of protecting water circulation systems from corrosion and salt deposition by introducing salt deposition inhibitors and corrosion inhibitor F1 into the water, which includes sodium tripolyphosphate, pyrophosphoric acid, sodium acetate and water, is the closest in terms of technical essence and the achieved result.

Hydrolyzed polyacrylonitrile (HIPAN) and disodium salt of ethylenediaminetetraacetic acid (Trilon B) are used as salt deposition inhibitors.

But the known method is characterized by insufficiently high efficiency in inhibiting corrosion and salt deposition due to the ability of GIPAN to form salt crystals on the heat exchange surface, which have high mechanical strength and are not washed away by water.

With long-term use of corrosion and salt deposition inhibitors, all surfaces in contact with inhibited water are covered with salt deposits. As the thickness increases, these salt deposits crack, which provokes the development of crevice corrosion. Chipped sediment plates partially cover the heat exchange tubes, which reduces the water flow rate and further increases salt deposits in the pla) tubes, until the tubes are completely clogged.

The basis of a useful model is the task of creating a method of protecting water circulation systems from corrosion and salt deposition, in which by changing the conditions of the process, in particular, the use of new substances, the possibility of the formation of salt crystals in the volume of water, and not on the heat exchange surface, is ensured. in

This problem is solved by the fact that in a known method of protecting water circulation systems from corrosion and salt deposition by introducing salt deposition inhibitors and FI corrosion inhibitor into the water, which includes sodium tripolyphosphate, pyrophosphoric acid, sodium acetate, and water, sodium salt of the copolymer is used as salt deposition inhibitors vinyl acetate and maleic anhydride (Ma-salt of SVAMA) or sodium salt of carboxymethylcellulose (Ma-salt of KMC) and oxyegylidene diphosphonic acid (OEDF) or its sodium salt. 3o The set task is also solved by the fact that the FI corrosion inhibitor is introduced in the amount of 1-10Omg/l (in -- converted to 10095 RO.) of the treated water.

The problem is also solved by the fact that salt deposition inhibitors are introduced in quantities, for example, SVAMA Mas-salt in the amount of 1-1Omg/l (in terms of 10095 salts) of the treated water or KMC Mas-salt in the amount of 1-10mg/l (in terms of 10,095 salts) of treated water or together with SVAMA Ma-salt and KMC Ma-salt in the amount of 1-10 mg/l. c The problem is also solved by the fact that the inhibitor of salt deposition, and in particular OEDF or its sodium salt, is introduced into the treated water in the amount of 1-1Omg/l (in terms of 100905 acid).

The applicant established that with the same dosage of salt deposition inhibitors, in particular Ma-salt of KMC,

Mas-salt SWAMA and GIPANU under the same conditions of water treatment, the most effective Mas-salt SWAMA and Mas-salt - 395 KMC. The authors established that due to the use of water-soluble polymers of Ma-salt SWAMA and Ma-salt

KMC together with OEDF, salt crystals are formed mainly in the volume of water, and not on the heat exchange surface. (o) Deposits that are partially formed on the heat exchange surface have low mechanical strength and are easily washed away by a stream of water.

The use of the proposed method of protecting water circulation systems from corrosion and salt deposits (ee) 50 ensures the receipt of specific benefits, in particular: "mch - compared to the prototype, crevice corrosion under deposits is reduced or completely prevented, the amount of salt deposits is reduced by 4 times or more. The proposed method includes the following operation - introducing corrosion inhibitor F1 into the water; 59 - inhibitors of salt formation: Mas-salt SVAMA or Ma-salts KMC, or together Mas-salt SVAMA and Ma-salts KMC; c - OEDF or its sodium salt;

As a FI corrosion inhibitor, the composition is used with the following ratio of components, wt. 90: sodium tripolyphosphate 14-16 60 pyrophosphoric acid 18-20 sodium acetate 1.0-2.0 water the rest.

The preproposal method is explained with examples. because Example 1

Water of the following composition is used as a medium for laboratory experiments:

total alkalinity 4.A4-4 bmg-eq/l; total hardness 9.8-10.2 mg-eq/l;

SI- 130-15Omg/l; pH 7-75.

0.1 ml of water is poured into a Tl container equipped with a heating shell and a barbitating device. Add to the water: 70 1Omg/l corrosion inhibitor FI1 (in terms of RO, U; 1Omg/l salt deposition inhibitor Ma-salt SVAMA or 1Omg/l Ma-salt KMC (in terms of 10095 salts); 2mg/l OEDF or Ma - OEDF salt (per 100905 acid).

The water is heated to 402C, the air bubbler is turned on. Next, measured and weighed samples of St3 carbon steel are placed in water for at least 200 hours. After the experiments, the rate of 7/5 Corrosion and the degree of protection against corrosion were calculated (table).

Example 2

As a medium for laboratory experiments, the same water and the same dosage of reagents are used as in example 1. Experiments on salt deposition in dynamic conditions were carried out on a laboratory stand that simulates the operation of a water circulation cycle.

Water circulated along the circuit:

Accumulation tank-submersible pump-heat exchanger-irrigator-accumulation tank.

Evaporation and splashing were compensated from the feeding tank. After the experiments, the amount of deposits in the heat exchanger was determined and the degree of protection against salt deposits was calculated (table). zv. Z

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Claims (4)

The formula of the invention 1. The method of protecting water circulation systems from corrosion and salt deposition by introducing inhibitors into the water - salt deposition and FI corrosion inhibitor, which includes sodium tripolyphosphate, pyrophosphoric acid, sodium acetate and water, which is distinguished by the fact that sodium salt Me copolymer of vinyl acetate and maleic anhydride (Ma-salt SVAMA) or sodium salt of carboxymethylcellulose (Ma-salt KMC) and oxyethylene diphosphonic acid (OEDF) or its sodium salt. 2. The method according to claim 1, which differs in that the FI corrosion inhibitor is introduced in the amount of 1-100 mg/l (in so calculation per 100 95 RO) of the treated water. "And Z. The method according to claim 2, which differs in that salt deposition inhibitors are introduced in quantities: for example, SVAMA Ma-salt in the amount of 1-10 mg/l (in terms of 100 95 salts) of the treated water, or KMC Ma-salt in the amount 1-40 mg/l (in terms of 100 95 salts) of treated water, or a combination of SVAMA Mas-salt and KMC Mas-salt in the amount of 1-10 mg/l. 4. The method according to claim 1, which differs in that the inhibitor of salt deposition, and in particular OEDF or its sodium salt, is introduced in an amount of 1-10 mg/l "in terms of 100 95 acid) of the treated water. Official Bulletin "Industrial Property ". Book 1 "Inventions, useful models, topographies of integrated circuit boards", 2006, M 7, 15.07.2006. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. b5