Composite corrosion inhibitor for seawater circulation cooling system carbon steel material anticorrosion

Abstract

The invention discloses a composite corrosion inhibitor for seawater circulation cooling system carbon steel material anticorrosion. The composite corrosion inhibitor comprises sodium molybdate, polyaspartic acid (PASP), benzalkonium bromide, sodium citrate and sodium silicate according to a mass ratio of 0.8-1.2:1.5-2.5:3.5-4.5:3.5-4.5:7.5-8.5. The corrosion inhibitor does not contain phosphorus (phosphine), difficultly decomposed polymers or heavy metal salts, so the corrosion inhibitor is harmless to environment; the corrosion inhibitor can reach a corrosion inhibition effect under a small dosage, so the use cost is reduced; and the corrosion inhibitor can control the carbon steel corrosion speed in a national standard allowed range in seawater and 2 times concentrated seawater, so the application range of the corrosion inhibitor is wide.

Description

technical field [0001] The invention belongs to the technical field of seawater corrosion inhibitors, and in particular relates to a composite corrosion inhibitor used for anticorrosion of carbon steel materials in a seawater circulation cooling system. Background technique [0002] Seawater circulation cooling refers to the process in which seawater is used as the cooling medium, and after the heat exchange equipment completes the primary cooling, the seawater is cooled by the cooling tower and then continues to be recycled. Since the 1970s, while exploring pollution-free anti-corrosion and anti-biological adhesion seawater direct-flow cooling technology, people have carried out research and development of seawater circulation cooling technology by referring to the relevant processes and technologies of fresh water circulation cooling. Compared with seawater once-through cooling technology and fresh water circulating cooling technology, seawater circulating cooling technolo...

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Problems solved by technology

[0005] (2) The proportion of chloride in the salt contained in seawater is very large, and the chlorine degree is as high as 19‰, so most metals such as iron, steel, cast iron, etc. cannot establish a passive state in seawater;

[0006] (3) There are many types and high content of microorganisms and large organisms in seawater, which are prone to biofouling, which in turn leads to more harmful microbial corrosion or under-scaling corrosion;

[0007] (4) Scaling ions in seawater such as Ca 2+ , Mg 2+ 、HCO 3 - , SO 4 2- The concentration of ions is much higher than that of fresh water. With the continuous evaporation of seawater in the circulating cooling process, its concentration ratio increases, and the scaling tendency also increases; when the concentration ratio increases to greater than or equal to 2.0, the scale-forming ions Dozens of times that of the cooling system, ordinary scale inhibitors and dispersants cannot effectively control chemical fouling deposition

[0017] However, the above-mentioned research on green corrosion inhibitors in seawater is mainly in the stage of theoretical research and laboratory exploration, and is still not perfect and mature in practical application.

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