Water treatment is essential for any type of cooling tower as it’s an important medium of cooling. Normal water used in industrial cooling towers contains many suspended particles like bacteria, debris, minerals, and other impurities. These impurities are known to develop scale in the cooling system and therefore, every cooling tower should have a water treatment plan.
Cooling is achieved by means of evaporation which leads to leftover water to be concentrated. Without water treatment, the performance of the cooling tower can be affected significantly. You can also take advice from your cooling tower manufacturer for water treatment. Water treatment does not only increase the efficiency of the cooling tower, but it saves water by making a significant proportion of industrial water reusable. The hard water scale can be managed by industrial water treatment.
The main reason for the hard water scale is the precipitation of calcium or magnesium suspended in the circulating water. The build-up of scale leads to poor cooling efficiency of the system, increased power consumption, and lower lifespan of the motor plant.
Different types of water treatment methods are in practice, such as R.O., softener, de-ionizer, etc. However, many cooling towers have opted for non-chemical water treatment for the best result.
What is non-chemical water treatment:
Non-chemical water treatment can be provided using a device that subdues the scale built up in the cooling tower, pipeline, and heat exchange. The device works with the combination of adsorption, turbulence and galvanic action.
However, the most suitable water treatment for any cooling tower can be determined based on the quality of feed water and chemistry of circulatory water. The general cooling tower water treatment includes clarification, filtration, softening, chemical feed, and automated monitoring.
Your cooling tower manufacturer can recommend the best water treatment system as per the system’s specifications. Before opting for any water treatment system, it is important to consult with a water treatment specialist. Based on the Cooling tower designs and its process, a standard combination of the water treatment system is applied. In case your tower requires a customized system, you may need to use advanced technologies.
What does a cooling tower water treatment system typically control?
Cooling tower water treatment system is created using the required technologies to regulate the level of chlorides, iron, alkalinity, TDS, silica, and other elements. Let’s see how these elements affect the industrial water used in the cooling tower.
Alkalinity is known to dictate the potential of calcium carbonate scale, while chlorides can be corrosive to metals. Hardness increases the scale built up in both cooling towers and heat exchangers and combined with phosphate, iron can damage equipment to failure. Organic matter in the water promotes microorganisms, which leads to corrosion, fouling, and other system-related issues. While silica known to cause hard scale deposits, TDS contributes to scaling and corrosion. Sulfates like chlorides are corrosive to metals.
How does the cooling tower water treatment system work:
The process of cooling tower water treatment system works based on the specific needs of the cooling tower, the chemistry of the feed and water circulation. However, a general water treatment system includes the following steps.
Cooling tower makeup water intake:
Whether your cooling tower needs water treatment or not can be determined based on the quality of your source water, which could be city water, raw water, recycled water, or any other surface water source.
Filtration and ultrafiltration:
It includes running the cooling tower water through a system of filtration which removes particles such as turbidity, sediment, and certain types of organic matter.
Ion exchange/water softening:
It removes the hardness in the source or makeup water, which can often lead to scale deposits and rust.
Chemical addition:
Generally, the chemicals used in the water treatment system are corrosion inhibitors, which neutralizes acidity in the system and protects metal, biocide, and algaecides to keep the growth of microbes and biofilms to a minimum, and scale inhibitors to prevent forming of scale deposits.
Side-stream filtration:
If the cooling tower water is to be recirculated in the system, then a side-stream filtration unit will be required in removing all sorts of problematic contaminants that have entered the system through a leak or drift contamination.
Blowdown treatment:
In this last step, cooling tower water is blowdown or bleed from the tower. It completely removes the liquid and solid waste from the tower and allows treated water to be reused.
Summary:
If you want to improves the performance of your cooling tower or maintain its current performance then you should frequently opt for cooling tower water treatment. The cooling tower water treatment will not only reduce the electricity cost significantly, but it will also increase the life of the system. Hire experienced professionals who can provide a cooling tower water treatment solution considering your specific requirement.
