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Cooling Water Treatment

Whether your cooling water application is an industrial process system with high heat flux across a mild steel heat exchanger or a commercial cooling system serving a centrifugal chiller in a large metropolitan high-rise, one fact is certain: without effective cooling water treatment, a cooling water system can suffer from scale formation, corrosion and fouling and may become a breeding ground for harmful bacteria such as those which cause Legionnaires’ disease. This reduces efficiency, shortens plant life and makes your operation unreliable and unsafe.

 

The purpose of a cooling water treatment program is essentially 3 fold:

ü  To protect the system against damaging corrosion.

ü  To control scale formation and fouling which will impair cooling efficiency.

ü  To control the growth of harmful microbes like Legionella bacteria, Algae etc.

These problems are interrelated and it is therefore essential that the treatment program tackles all of them.

 

YunRui electrochemical water treatment descaling equipment to protect the complete cooling system:

ü  Descaling

ü  Corrosion Mitigation

ü  Sterilization

ü  Alge eliminating

ü  Deposits Control

 

CONCENTRATION FACTOR & BLEED-OFF CONTROL

An evaporative cooling system works by transferring heat from the process being cooled to the recirculating cooling water at a heat cooling treat exchanger and then rejecting that heat at the cooling tower by evaporating a small proportion of the water. Evaporating just 1.8% of the recirculating flow achieves a temperature reduction of 100ᵒC. Since water is

evaporated as pure H2O the dissolved minerals (TDS) in the remaining cooling water become more concentrated. Some increase in the concentration factor is often beneficial since it tends to make the cooling water less corrosive but if it this allowed to go unchecked it can lead to scale formation and fouling. It is therefore often necessary to control the concentration factor by bleeding-off or blowing down a proportion of the cooling water and replacing it with less concentrated make-up water. This is best done using a conductivity controlled bleed-off system which automatically controls the concentration factor at the desired conductivity.

 

COOLING TOWER SCALE CONTROL

Scale or lime-scale is a hard, rock-like deposit of calcium or magnesium salts that forms in heat exchangers and cooling tower boiler-scale packing as a result of heat and increased concentration factor. Scale formation impairs heat transfer, interferes with flow and cooling, and can be a breeding ground for legionella bacteria. The scaling tendency of a water supply will depend on the hardness of the water but if not adequately treated even relatively soft waters can become highly scaling when concentrated by evaporation. YunRui equipment has pre-scaling technique that prevents scaling at the beginning. Through electrolysis, the scale ions in the water will be precipitated on the cathode surface and then be removed by the scrapper. Electrolysis reaction chamber maintained a certain current, a number of high concentration of hydroxide ions are formed close to the cathode (reaction chamber wall), such elevated pH environment (pH about 13) will make easy scaling of scaling minerals and precipitated from water, adsorbed on electrolytic reaction chamber wall. Under automatic control system, the scraper will scrape down the scales and automatically discharged.

 

COOLING TOWER MICROBIOLOGICAL CONTROL

An evaporative cooling system is often an ideal growth environment for a whole range of microbes micro such as bacteria, algae, fungi and protozoa which can lead to problems such as:

Microbial slimes which interfere with heat transfer

ü  Highly localised microbial induced corrosion

ü  Reduced effectiveness of corrosion inhibitors

ü  Fouling caused by suspended solids being trapped in the microbial slimes

ü  Reduced flow and poor water distribution within the cooling tower

Effective cooling water microbiological control is not only essential to the efficient operation of a system but also necessary to control the growth of legionella bacteria and the risk of Legionnaires disease. In order to maintain microbial control effective biocides need to be added on a regular basis and the results monitored using dip-slides and periodic laboratory analysis.

 

A large number of O3、OH-、O-2、H2O2、1O2 are released while functioning, which has a strong bactericidal effect. Together with the patented copper & silver ion collector, 99.8% of the bacteria and algae in water will be removed, including Legionella.

 

Contact us to help you prevent microbial problems in cooling system and discuss our range of cooling water treatment chemicals.

 

FOULING CONTROL

Controlling scaling, corrosion and microbial growth will reduce problems of fouling but a cooling system may still become fouled with fouling sediment in the incoming water supply (particularly if it isn’t mains water) and airborne dust and debris washed out of the atmosphere by the cooling tower. In some instances, fouling may also be the direct result of process contamination. Deposits tend to settle in low-velocity areas and can cause reduced flow, blockages, impaired heat transfer, under deposit corrosion and encourage microbial growth including legionella. If the incoming water contains a lot of suspended solids then pre-filtration or clarification may be advisable. To keep the suspended solids mobile in the recirculating water the chemical program should always incorporate a polymer dispersant and if the solids level is high then the incorporation of a side stream filtration system in a of the cooling circuit will help to keep the system clean. Since an evaporative cooling system is in effect an air scrubber so some build-up of deposits with time is inevitable so in addition to these on-going control measures the system should be taken off-line periodically for disinfection and the physical cleaning. Contact us to help you keep your cooling system free from fouling.

 

Treatment for Cooling Water Systems and Cooling Towers

 

Cooling Water Systems are used in virtually every facility, from commercial & institutional HVAC systems to process systems in large scale industrial plants. If left untreated, the metal surfaces of cooling towers, chillers, heat exchangers and associated piping that make up cooling water systems can corrode, develop scale and fouling or become choked with microbiological growth.  Having an ongoing cooling tower water treatment program is the best way to prevent legionella and other harmful waterborne pathogens from growing in your cooling tower. It is imperative from an energy efficiency viewpoint as well as an ecological perspective that the proper, high quality cooling tower water treatment program be selected, optimized and administered.

 

To meet the needs of our customers, YunRui offer protection and extended equipment life for open recirculating (cooling tower water treatment), closed loop and once-through cooling systems.  YunRui provides both of the elements critical to maintaining an effective program: high quality treatment products and individuals with the training and experience to properly apply them.  Our high performance equipment not only maintain, but often increase energy efficiency in our customer’s cooling systems while minimizing or eliminating unscheduled downtime or interruptions. We tailor every system and solution to meet the specific needs of each facility of each customer, including environmental requirement and regulations. We are also offer highly specialized cooling tower water treatment systems like YunRui.

 

We carry a complete line of treatment products to meet the needs of our customers:

ü  Advanced corrosion & scale inhibitors for low and high hardness waters

ü  Protection from “white rust” for systems with galvanized steel

ü  A complete line oxidizing and non-oxidizing microbiocides

ü  Unique dispersants for iron, salt, biomass & slime-forming bacteria and other problematic substances

ü  Threshold inhibitors for once-through systems

ü  Various state-of-the-art inhibitors for treatment of closed loop systems

ü  Specialized products (including vapor phase inhibitors) for off-season protection

ü  Glycol products and associated inhibitors for protect of winterized systems

ü  Risk assessments for Legionella and treatment solutions for sterilization and decontamination of compromised systems

ü  A wide selection of equipment options for monitoring our programs from simple analog controllers to sophisticated instruments for coordinated control of inhibitors, biocides, pH and ORP with modem linkage to remote sites complete with statistical process control and trend monitoring.