Circulating cooling water treatment

Cooling Water Treatment



The cooling water is widely used in electric power, chemical industry, metallurgy, fertilizer and other industries, as well as the low-pressure boiler, oil field water, pipelines;Although  industrial cooling water by filtration, purification process, using water quality standards, but in the cycle of physical and chemical conditions change, water quality has changed, a variety of ion concentration, increasing the amount of dissolved gases, contact with the atmosphere produce bacteria;

water contains calcium and magnesium salts -- commonly referred to as "Hardness." These salts have only limited solubility ,when the "limit of solubility" is reached,long-term use of the circulating cooling water will appear as calcium carbonate, calcium sulfate, barium sulfate, calcium chloride, zinc scale microcrystalline or sediment in the water, these precipitated material will greatly reduce the Role of circulating cooling water,  therefore be corrosive to equipment, damage to production equipment, affecting the normal production run. 

In addition to dissolved "solids," water usually contains dissolved gases which it picks up from the air. The two most prevalent are oxygen and carbon dioxide. other gases, such as sulfur dioxide or nitrogen oxides from exhaust fumes, can form acids when dissolved in water. These dissolved gases can, in time, completely destroy parts of the tower. Thus, the water must be conditioned to prevent acidic corrosion.

Another problem results when the moist surfaces of the tower are exposed to sunlight. This promotes the growth of algae, bacteria and fungal slime. Large masses of slime or algae growth can accumulate rapidly, causing clogging, reduced flow, and reduced heat transfer. This "fouling" must be prevented.

To ensure circulating cooling systems are well maintained and operate at optimum efficiency, it is essential that the correct water conditions are maintained at all times.

Outer water treatment (Units and equipment) filtration, softening, desalination Internal water treatment (chemical products) Inhibitors for corrosion and scaling, antimicrobials; The operating efficiency of a circulating cooling system is adversely affected by:

(1)  Scaling, which must be controlled chemically and also held in check by bleed-off.

(2) Corrosion, which must be overcome by chemically neutralizing the acidity which has been picked up by air pollution, or which is present in the makeup water.

(3)Organic fouling, which must be brought under control by chemicals with algaecidal properties.



HOO CHEMTEC’s cooling water chemical programs are effectively used for the reduction and prevention of the three major issues your industrial cooling water system may encounter: corrosion, deposition, and microbial growth.

Corrosion leads to metal loss that can result in critical system failures in heat exchangers, recirculating water piping, and process cooling equipment. Corrosion also results in a loss of efficiency as corrosion products precipitate on heat transfer devices, insulating the metals.

Cooling water systems are vulnerable to a variety of contaminants that cause deposit formation, such as mineral scales and sludge. Deposition interferes with heat transfer, increases corrosion rates, restricts water flow, and causes loss of process efficiency and production.


Biological organisms, including algae, bacteria, protozoa, and fungi, often find their breeding grounds in cooling water systems. If not properly controlled, biological growth forms and acts as a natural adhesion surface for scale formation, resulting in fouling.

All of these conditions can be seriously problematical when it comes to optimizing the efficiency of your circulating cooling water tower or system.HOO CHEMTEC’s full range of cooling water chemicals can provide excellent protection against these cooling system challenges.


HOO CHEMTEC’s advanced technology cooling water scale and corrosion inhibitors have been scientifically formulated to protect cooling systems from the effects of both scale build-up and metallic corrosion ;

Our range of formulated cooling water treatment chemicals includes antifoam, biocides (oxidizing and non-oxidizing), biodispersants, corrosion inhibitors, disperansts and scale inhibitors for cooling tower systems.

Products and methods of treatment


Generally, the chromate or molybdate types have proven to be superior treatments. For mixed metallurgy systems, the molybdate inhibitors provide the best corrosion protection.Inorganic corrosion inhibitor chromate and dichromate is currently available for circulating cooling water system in the most effective a corrosion inhibitor. It is an oxidation inhibitor.

In a closed system, it can be quite difficult to prevent corrosion of aluminum and its alloys; the pH of the water must be maintained below 9.0. Aluminum is amphoteric-it dissolves in both acid and base, and its corrosion rate accelerates at pH levels higher than 9.0. The bimetallic couple that is most difficult to cope with is that of copper and aluminum, for which chromate concentrations even higher than 5000 ppm may not be adequate.

Molybdate treatments provide effective corrosion protection and an environmentally acceptable alternative to chromate inhibitors. Nitrite- molybdate-azole blends inhibit corrosion in steel, copper, aluminum, and mixed-metallurgy systems. Molybdates are thermally stable and can provide excellent corrosion protection in both soft and hard water


Nitrite is another widely accepted nonchromate closed cooling water inhibitor One drawback to nitrite treatments is the fact that nitrites are oxidized by microorganisms. This can lead to low inhibitor levels and biological fouling. Nitrite is also a kind of oxidation inhibitor, so it is mainly used for equipment cooling after pickling passivation agent and closed circulating cooling water system in the non chromate corrosion inhibitor.


Poly phosphate is one of the most widely used and most economical cooling water corrosion inhibitors. The most commonly used is sodium phosphate and sodium six sodium phosphate. The latter is better than the former. Poly phosphate and chromate, molybdate, organic phosphonate compound had synergistic effect. The disadvantage is that it is easy to be hydrolyzed to produce positive phosphate, especially in the system with high heat exchange temperature, long time in the residence time of the medicament, and the hydrolysis is greater. Calcium ion in the water of the hydrolysis product and the calcium ion in water can produce calcium phosphate, and can promote the growth of algae. Thus, the tendency of the organic phosphate to be replaced by organic phosphate is gradually replaced;

Organic polybasic phosphonic acid, it is a cathodic corrosion inhibitor, through a combination of multivalency chelation and iron, calcium ions, on the surface of the metal forming a layer can inhibit the corrosion protective film, HEDP and ATMP (amino trimethylene phosphonic acid) (hydroxy ethylidene diphosphonic acid) and EDTMP (ethylene diamine tetra (methylene phosphonic acid) and

Foreign corrosion inhibitor development direction due to phosphorus emissions will cause pollution to the environment, so in recent years foreign working on developing new low phosphorus and phosphorus free products, such as: amino methylene phosphonic acid, poly tyres, alkyl epoxy carboxylate, poly aspartic acid etc.

Hoo chemtec supplies a comprehensive range of speciality antiscalent, cleaning and dispersing products, along with corrosion inhibitors and biocide formulations that can be used in all applications under all operating conditions.We are one of the leading suppliers of products to clarify the raw water used for the production of drinking water, treating the waste water stream and reducing sludge volumes as well as for the treatment of industrial process water and the protection of desalination plants, cooling towers and boilers.


Effective heat transfer in cooling systems is essential. Different cooling systems demand different types of treatment to eliminate scaling, corrosion and bio-fouling. Water Solutions business includes products used in the key processes of municipal and industrial water treatment.

Basics of treatment products : phosphonic acids and phosphonates scale inhibition corrosion protection

Polycarbonic acids / polycarbonates dispersing agent

 mobilisation of sludge scale inhibition

organic N-heterocyclic compounds (Triazoles) corrosion inhibition of yellow metals additives for stabilisation of the formulation

maintaining cooling tower efficiency requires effective chemical treatment programs for the prevention of scale,corrosion and biological fouling.Providing water treatment chemicals for the prevention of scale, corrosion and biological fouling.

Organic phosphoric acid:

HEDP is a kind of organic phosphoric acid scale inhibitor


ATMP amino group




- inorganic phosphate

Six sodium phosphate, sodium phosphate

- non phosphorus corrosion inhibitor

Poly aspartate

Sodium polyacrylate

Poly epoxy

- copper and acid pickling corrosion inhibitor

Benzo triazole BTA three

Mercaptobenzothiazole sodium MBT