Power plant water treatment chemicals

 Power plant water treatment chemicals are used in the power plant water treatment system to ensure that the water quality meets the operating requirements of power generation equipment, the following are some common power plant water treatment chemicals and their role, characteristics and other information:

Flocculant

    Role: through electric neutralization, adsorption and bridging, etc., so that the suspended particles in the water, colloids and other impurities coagulated into larger flocs, to facilitate subsequent precipitation, filtration and other treatments, so as to remove the suspended matter in the water and part of the organic matter, to improve the clarity of the water.

    Commonly used types: inorganic flocculants such as polymerized aluminum chloride (PAC), polymeric ferric sulfate (PFS); organic flocculants such as polyacrylamide (PAM), according to its ionic properties can be divided into cationic, anionic and nonionic.

    Characteristics: inorganic flocculants flocculation speed, but the formation of the floc is relatively small; organic flocculants flocculation effect is good, the floc is large and settling speed, but the price is relatively high.

Auxiliary coagulant

    Role: assist the flocculant to play a role in improving the flocculation effect, enhance the strength of the floc and settlement performance, in low temperature, low turbidity and other difficult to deal with water quality conditions, can significantly improve the flocculation effect.

    Commonly used types: activated silicic acid, sodium polyacrylate and so on.

    Characteristics: generally does not have flocculating effect itself, but it can synergize with flocculant to improve flocculation efficiency and reduce the dosage of flocculant.

Bactericide

    Role: kill or inhibit bacteria, algae and other microorganisms in the water, prevent microorganisms from breeding and reproducing in the water treatment system, avoid microbial corrosion and the production of biological slime, to ensure the normal operation of the system and the stability of water quality.

    Commonly used types: oxidizing biocides such as liquid chlorine, chlorine dioxide, sodium hypochlorite, etc.; non-oxidizing biocides such as quaternary ammonium salts, isothiazolinones, etc..

    Characteristics: oxidizing biocides sterilization speed, sterilization effect is good, but may be corrosive to some materials in the system; non-oxidizing biocides have a broad-spectrum, high efficiency, low toxicity and other characteristics, and is not subject to the impact of ammonia and nitrogen in the water and other substances, but the long-term use of microorganisms may produce drug resistance.

Corrosion Inhibitors

    Role: to form a protective film on the metal surface, preventing dissolved oxygen, acid and alkali corrosive substances in the water from contacting the metal, thus slowing down the corrosion rate of metal equipment and prolonging the service life of the equipment.

    Commonly used types: anodic corrosion inhibitors such as chromates, nitrites, etc.; cathodic corrosion inhibitors such as zinc salts, polyphosphates, etc.; mixed corrosion inhibitors such as organic amines, mercaptobenzothiazole and so on.

    Characteristics: anodic corrosion inhibitor can inhibit the anodic dissolution of metal, but the dosage may accelerate the local corrosion; cathodic corrosion inhibitor to slow down the corrosion of the cathodic reaction through the inhibition of cathodic corrosion inhibitor, generally safer; mixed corrosion inhibitor both anodic and cathodic corrosion inhibition, the effect is better.

Scale inhibitor

Role: Through lattice distortion, dispersion, chelation and other effects, to prevent calcium, magnesium, iron and other metal ions in the water to form insoluble scale, to prevent scale deposition on the surface of heat exchangers, pipelines and other equipment, to improve the efficiency of heat transfer and operational efficiency of the equipment.

Commonly used types: polycarboxylic acid scale inhibitors such as polyacrylic acid, polymaleic acid, etc.; organic phosphonate scale inhibitors such as amino-trimethylene phosphonic acid (ATMP), hydroxyethylene bisphosphonic acid (HEDP) and so on.

Characteristics: Polycarboxylic acid scale inhibitor has good inhibition effect on calcium carbonate, calcium sulfate and other scale, and has a dispersing effect; Organic phosphonate scale inhibitor has a strong chelating ability to a variety of metal ions, scale inhibition effect is good, especially for high hardness, high alkalinity water quality.

Oxygen remover

Role: remove dissolved oxygen in water, prevent dissolved oxygen in water from corrosion of metal equipment, is one of the important measures to prevent corrosion of thermal equipment.

Commonly used types: chemical deoxidizers such as sodium sulfite, hydrazine, etc.; new deoxidizers such as oxime compounds, carbonylhydrazine, etc..

Characteristics: sodium sulfite deoxygenation speed, but will increase the salt content of the water; hydrazine deoxygenation effect is good, but the toxicity is greater; oxime compounds and carbonylhydrazine and other new deoxidizers deoxygenation efficiency, low toxicity, and is gradually being widely used.