Cooling Water Treatment Chemicals

Cooling Tower Water Treatment Chemicals

Water is used widely as a cooling medium in processes for many industries and public buildings. The use of an evaporative cooling tower is still the most effective method of heat transfer. Heat is transferred from hot process fluids into the cooling water through a heat exchange surface; consequently, the cooling water heats up. The evaporation of a small percentage of this cooling water in a cooling tower, then reduces the temperature of the cooling water, allowing it to be used for cooling again. Make-up water is used to replace the evaporated water.

Evaporative condensers are often used to cool closed systems whereby pipework containing hot process fluids is sprayed with water to remove heat from the system. The primary objectives in the design, operation and effective treatment of cooling water systems include efficiency in heat transfer, minimisation of energy and water usage, and safe, reliable operation.

When operating a cooling system, there are several considerations to ensure the achievement of these objectives, which include the control of scale, corrosion, fouling, and the control of microbiological contamination including Legionella spp.

Our range of cooling tower water treatment chemicals

Zagosa Industrial have a full range of cooling tower water treatment chemicals. This range also contains many specialist products formulated for use in specific specialist situations or for use in response to problematic situations. Our Technical department is always available for advice on product selection, problem solving, and compatibility with other formulations already being used in certain systems. A summary of our core range of products is below, many other formulations for cooling water systems are also available.

Scale and Corrosion Inhibitors

Product code Composition Comments

ZI46

A blend of phosphonates, polymers and azoles

Concentrated all organic corrosion and scale inhibitor for soft waters. Suitable for water hardness 25 – 250ppm

ZI47

A blend of phosphonates, polymers and azoles

All organic corrosion and scale inhibitor for soft waters and smaller systems. Suitable for water hardness 25 – 250ppm

ZI664

A blend of phosphonates, polymers and azoles

All organic corrosion inhibitor for medium hardness waters.

ZI640

A blend of phosphonates, polymers and azoles.

High strength all organic corrosion inhibitor for high hardness waters.

ZI48

A blend of phosphonates, polymers and azoles.

Medium strength all organic corrosion inhibitor for high hardness waters.

ZI49

A blend of phosphonates, polymers and azoles.

Low strength all organic corrosion inhibitor for high hardness waters.

ZI45

A blend of phosphonates, polymers and azoles & sodium bromide

All organic corrosion inhibitor for naturally soft waters. Contains sodium bromide for cost effective generation of hypobromous acid when dosed with sodium hypochlorite.

ZI50

Silicate based soft water inhibitor

Concentrated low toxicity silicate based corrosion inhibitor for naturally soft and softened water.

ZI51

Silicate based soft water inhibitor

Low toxicity silicate based corrosion inhibitor for naturally soft and softened water. Suitable for use in smaller systems.

ZI52

Sodium molybdate based soft water inhibitor

Concentrated high molybdate based corrosion inhibitor designed for soft water. Benefits from some hardness being present.

ZI53

Sodium molybdate based soft water inhibitor

A high molybdate based corrosion inhibitor designed for soft water. Benefits from some hardness being present. Designed for smaller systems.

ZI1260

Sodium molybdate based soft water inhibitor

Cost effective molybdate based soft water inhibitor. Benefits from some hardness being present

ZI540

A blend of phosphonates, phosphates, polymers and azoles.

A phosphate based product specifically designed for the passivation of Galvanised towers.

ZI250

Supplementary product to control phosphates where there are high levels of phosphates in make-up water.

A blend of polymeric dispersants.

ZI197

Zinc based corrosion and scale inhibitor

A zinc based corrosion inhibitor for cooling towers.

ZI472

An acidic zinc based aqueous solution.

A specialist scale and corrosion inhibitor for use in cooling systems, can processing, pasteurisation, and sterilisers.

Scale and Corrosion Inhibitors (+ Sodium Bromide)

Often, cooling tower biocidal treatment is accomplished with bromine based oxidizing biocides generated from dosing sodium bromide solution in conjunction with sodium hypochlorite. On some sites it is more convenient and economical to dose a scale and corrosion inhibitor containing sodium bromide in conjunction with sodium hpochlorite in order to generate hypobromous acid for microbial control.

Product code Composition Comments

ZI456

A blend of phosphonates, polymers and azoles & sodium bromide

All organic corrosion inhibitor for medium hardness waters. Contains sodium bromide for cost effective generation of hypobromous acid when dosed with sodium hypochlorite.

ZI457

A blend of phosphonates, polymers and azoles & sodium bromide

All organic corrosion inhibitor for high hardness waters. Contains sodium bromide for cost effective generation of hypobromous acid when dosed with sodium hypochlorite.

ZI785

Silicate based soft water inhibitor & sodium bromide

Concentrated low toxicity silicate based corrosion inhibitor for naturally soft and softened water. Contains sodium bromide for cost effective generation of hypobromous acid when dosed with sodium hypochlorite.

ZI974

Zinc based corrosion and scale inhibitor & sodium bromide

A zinc based corrosion inhibitor for cooling towers. Contains sodium bromide for cost effective generation of hypobromous acid when dosed with sodium hypochlorite.

Scale and Corrosion Inhibitors (+ Biodispersant)

Biofilm build up within a system will greatly inhibit the heat transfer efficiency of the system as well as blocking pipework. A build-up of biofilm within a system will also encourage the growth of Legionella bacteria and may promote the formation of under deposit corrosion. Biodispersants can be incorporated in the treatment regime for cooling towers in a number of ways including within the formulations of some of our range of scale and corrosion inhibitors.

Product code Composition Comments

ZI1437

A blend of phosphonates, polymers and azoles & biodispersant

All organic corrosion inhibitor for low hardness waters. Contains biodispersant.

ZI1436

A blend of phosphonates, polymers and azoles & biodispersant

All organic corrosion inhibitor for high hardness waters. Contains biodispersant

ZI1435

Silicate based soft water inhibitor & biodispersant

Concentrated low toxicity silicate based corrosion inhibitor for naturally soft and softened water. Contains biodispersant

ZI1438

Sodium molybdate based soft water inhibitor & biodispersant

Cost effective molybdate based soft water inhibitor. Benefits from some hardness being present. Contains biodispersant

ZChem Range

As well as the scale and corrosion inhibitors listed above, we also have our ZChem range; a range of extremely concentrated, economical in-use corrosion and scale inhibitors used in larger industrial systems. Please contact our technical department for further details on this range 

Biocides

The water within a cooling system provides optimal growth conditions for many species of bacteria, including Legionella spp. The warm environment and high levels of organic debris make for a particularly pleasant environment for rapid bacterial growth if this is left uncontrolled.

Legislation requires that cooling towers must prevent the proliferation of Legionella bacteria within these systems as a precaution against the outbreak of Legionnaires disease. It is therefore critical that the correct biocidal treatment regime is implemented and regular checks are carried out to ensure that bacterial populations within the system are kept under control.

Biocides can be divided into 2 main groups; oxidising biocides and non-oxidising biocides:

  • Oxidising biocides simply oxidise microbial cells and will kill most micro-organisms including bacteria, algae, fungi, and yeasts.

  • Non-oxidising biocides kill microorganisms typically by disrupting the organism’s metabolism or damaging the cell wall.

Biodispersants do not kill organisms but they do break up any deposits of microorganisms allowing the biocides to attack the organisms more effectively. They also inhibit the attachment of microorganisms to metal surfaces.

Oxidising Biocides

Product code Composition Comments

ZI102

Sodium Hypochlorite

Sodium hypochlorite 14/15%

ZI54

14/15% sodium hypochlorite + biodispersant

A chlorine-based biocide for the treatment of cooling towers. Dosed 1:1 with ZI1422 to generate hypobromous acid

ZI1422

Sodium Bromide solution

A solution of sodium bromide for the treatment of cooling towers. Dosed 1:1 with ZI54 to generate hypobromous acid.

ZI138

Concentrated sodium bromide sdolution

A solution of sodium bromide for the treatment of cooling towers. Dosed 1:3 with ZI54 to generate hypobromous acid.

ZI476

Bromine tablets – UK BPR Registered for PT11 Application

A mixture of brominated and chlorinated hydantoins. Releases both bromine and chlorine in the form of hypobromous acid and hypochlorous acid. The product should be dosed using a purpose built brominator to ensure good dose control.

ZI923

A stablised hypobromite solution

Stabilised Bromine biocide. Single dose product. For use as a biocide in the treatment of cooling towers. Dose 15ppm product to give 1-2ppm bromine.

Non-Oxidising Biocides

Product code Composition Comments

ZI63

Concentrated THPS based biocide & biodispersant

Low toxicity. Excellent against Pseudomonas spp, Legionella spp and algae. Concentrated formulation. The biodispersant in the formulation enhances biocidal activity, removes biofilm and prevents the formation of additional biofilm.

ZI1531

ITA blend

A highly effective broad spectrum biocide. Effective against Legionella.

ZI105

BNP

A broad-spectrum bactericide. Low toxicity. Effective against Legionella.

ZI1507

Glutaraldehyde

Has a broad spectrum of activity against bacteria and their spores, fungi, also effective against Legionella spp. Rapid biocidal action. Concentrated product.

ZI1528

Proprietary

A highly effective non-oxidising biocide containing a synergistic combination of biocides. Ideal for use in closed circuit or open cooling systems. Effective against, Pseudomonas spp and Legionella spp.

ZI529

DBNPA

Has a broad spectrum of activity against bacteria and their spores, fungi, also effective against Legionella spp. Rapid biocidal action.

ZI67

Quaternary ammonium chloride

A broad spectrum disinfectant and biocide. Effective against Legionella. Effective in heavily soiled systems. Good surfactant properties. Rapid biocidal action.

ZI66

Contains a polymeric quaternary ammonium compound

Very effective algaecide for use in open cooling systems and swimming pools

ZI14

Concentrated biodispersant

Extremely low foaming. Improves the effectiveness of any biocide programme.

ZI963

Biodispersant

Extremely low foaming. Improves the effectiveness of any biocide programme.

Product code Composition Comments

ZI2

Mineral Hydrocarbon

Versatile antifoam which can be used in open cooling, process water and waste water treatment applications. Low dose rate, long lasting antifoam

Pack Cleanse Range

Our PackCleanse cleaning system; effectively cleans light to moderately fouled packs in place by combining the disinfecting power of chlorine dioxide, with the cleaning power of a weakly acidic surfactant mixture. The system produces a high-cling foam which is applied to surfaces to be cleaned under low pressure. The design of the dosing equipment is important. A stable wet foam is essential. Please contact us for advice on the optimal equipment for use in applying this range of products.

Product code Composition Comments

ZI740

phosphoric acid and surfactant

Foam cleaning detergent for the cleansing of cooling tower pack. Forms a stable wet foam that is able to slowly flow through the tower packing. Mildly acidic so as to remove inorganic scales. An effective alternative cleaning solution where it is not possible to remove cooling tower pack.

ZI741

phosphoric acid and surfactant

Foam cleaning detergent for the cleansing of cooling tower pack. Low acid version of ZI740.

ZI743

Contains stabilised chlorine dioxide.

A powerful disinfectant for use in the cleaning and disinfection of cooling tower packing. Activated when mixed with ZI740 or ZI741.

ZI744

Silicone based antifoam

De-foamer for use in cooling tower foam cleaning. Breaks down stable acidic foam. Apply to the tower sump at the end of the pack cleaning procedure.

ZI745

Contains acid and chlorine neutralisers.

Neutraliser for use in cooling tower foam cleaning

Specialist on-line descaler for cooling towers

Product code Composition Comments

ZI846

Contains a unique polyphosphonate.

A very effective calcium carbonate and calcium sulphate scale inhibitor which also effectively removes calcium carbonate scale on-line during normal cooling tower operation.

Acid descalers

Product code Composition Comments

ZI78

28% Hydrochloric acid.

For acid descaling.

ZI1535

Hydrochloric acid 32% + corrosion inhibitor

A highly active acid cleaner and descaler. Also includes a corrosion inhibitor to protect bare metal surfaces particularly carbon steel. Removes both calcium and iron deposits.

ZI13

Aliphatic amine based corrosion inhibitor

Confers corrosion inhibition during descaling with Hydrochloric acid

ZI42

Sulphamic acid crystals

Mild acid descaler. Crystals. Dissolve in water to produce a 5 – 10% solution.

ZI43

Sulphamic acid crystals + amine based corrosion inhibitor.

A highly active combination of acid cleaner and descaler with corrosion inhibitor to protect carbon steel, copper and brass against acid attacks. It can be used on a wide variety of metals including stainless steel. Dissolve crystals in water to produce a 5 – 10% solution then add inhibitor as instructed on product data sheet.

ZI231

Sulphamic acid solution

Ready to use Sulphamic acid descaler.

ZI1427

Formic acid

Less corrosive than hydrochloric acid. Recommended for stainless steel.

ZI532

Formic acid + corrosion inhibitor

Less corrosive than hydrochloric acid. Recommended for stainless steel. Corrosion inhibitor included.

ZI8

Mineral oil based antifoam

Gives foam control during descaling operations.

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