Application Note: Chlorination In Industrial Cooling Water Systems

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•Application Note: Chlorination In Industrial Cooling Water Systems

Background
Chlorine is one of the most widely used chemicals for biofouling control in industrial cooling water systems. When properly applied at water intake screens, chlorine helps to control zebra mussels, asiatic clams, and other marine organisms that grow in cooling water environments. In fresh water recirculating cooling water systems, the addition of chlorine helps control the formation of algae, slime growth, zebra mussels and asiatic clams.

Increased fuel, operating and construction costs have forced large users of cooling water to strive for maximum thermal and mechanical efficiency. This requires, above all, clean heat exchanger and condenser surfaces to produce the best possible heat transfer and cooling efficiency. Maintaining clean condenser tubes and unrestricted cooling water flow requires careful control of mineral scaling, corrosion, deposition of suspended matter, and biofouling.

Problem
Biofouling, in addition to restricting heat transfer, often serves as the "glue" that binds other deposits to the heat transfer surfaces.

Conditions in a typical industrial or electric utility cooling water system are close to ideal for biological and marine growth. The water source is often a river, lake, or coastal water. Each contain all the naturally occurring organisms and nutrients that are required for biological growth.

Inorganic and organic phosphates are often used for corrosion control, thus adding additional nutrients. This, in addition to water temperatures of 90° to 100°F (32° to 38°C), and a pH range of 8 to 9, provide an ideal environment for biological growth.

Under these conditions, control of biofouling is essential in maintaining operating efficiency. At the same time, it is important, for both cost and environmental reasons, to use chlorine as efficiently as possible. For example, in the United States, the electric utility industry has environmental limits on the discharge of residual chlorine to the receiving water supply. To meet these limits, dechlorination is often required before water is discharged from the plant.

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Click Here To Download:
•Application Note: Chlorination In Industrial Cooling Water Systems