Remember Your Closed Cooling Systems

H2 Global Solutions
3 days ago
1 min read

Plant personnel often prioritize primary cooling water systems while overlooking the many closed cooling water systems. However, failure in a closed system can lead to partial plant shutdown.

Operators sometimes use untreated service water for makeup, but high-purity condensate provides better chemistry control. Well-maintained closed systems require minimal makeup, and using condensate reduces scale formation.

Concerns for Closed Cooling Water Systems

Corrosion Control

Corrosion control is the primary concern and is typically managed with agents such as sodium nitrite or sodium molybdate. These chemicals help carbon steel components form a passive layer when maintained at proper concentrations.

Weekly monitoring and chemical replenishment are standard practices. For systems with copper-alloy heat exchanger tubes, azole compounds are effective for corrosion protection.

Microbiological Growth

Certain treatment programs, such as those using nitrites, may permit microbiological growth in closed systems. This fouling can restrict heat transfer and block small-bore piping.

Nonoxidizing biocides are available for both open and closed systems, and product selection is often straightforward with laboratory analysis of the organisms present.

Anti-Freeze

Some closed systems, especially in northern climates, use glycol to prevent winter freezing. It is important to periodically check the anti-freeze concentration and pH.

Over time, glycol decomposes into small-chain organic acids, which can increase corrosion risk. Occasional bleeding and refilling may be required.

H2 Global Solutions won't forget to take care of your closed cooling water systems.