Cooling Tower Cleaning
Cooling towers are susceptible to many of the same contaminants found in heat exchangers and condensers. Just like these systems, cooling towers require regular cleaning to ensure optimal performance. The removal of debris and mineral scaling that can impede heat transfer and reduce efficiency should be a primary focus of any cooling tower cleaning routine. However, preventing performance degradation isn’t the only reason for cleaning. Cooling towers can also become breeding grounds for legionella bacteria, which pose serious health risks. Legionella bacteria, if present, can become airborne and potentially affect surrounding areas, making it crucial to focus on preventing its growth as part of routine maintenance.
Legionella in Cooling Towers:
Legionella is a type of bacteria that can cause illnesses ranging from mild respiratory conditions to more severe, pneumonia-like symptoms. This more serious condition, known as Legionnaires’ disease, can be fatal if not promptly treated with antibiotics. Cooling towers are the most common source of Legionnaires’ disease outbreaks due to their widespread use in industrial and commercial settings, especially for air conditioning systems in densely populated areas. The design of cooling towers facilitates the airborne spread of the bacteria, while the water temperature in these systems (typically between 68-122°F) provides an ideal environment for legionella growth.
To combat the risk of legionella, it is essential to implement proper cleaning and maintenance practices. The OSHA Technical Manual provides in-depth guidelines on cooling tower maintenance in relation to legionella prevention, as outlined in Section III, Chapter 7.
Frequency of Cleaning: Cooling towers should be cleaned and disinfected at least twice annually. This maintenance is typically performed before the system’s initial start-up at the beginning of the cooling season and after it’s shut down in the fall. Systems with significant biofouling or high Legionella levels may require more frequent cleaning. Any system that has been out of service for an extended period should be cleaned and disinfected. New systems also need cleaning and disinfection to remove construction debris, which can promote Legionella growth.
The OSHA manual also provides detailed recommendations for cooling tower cleaning procedures, including using biocides such as chlorine and bromine to eliminate Legionella bacteria.
The Cooling Tower Cleaning Process:
Hyper Cool cleaning’s services follow OSHA guidelines, not only focusing on Legionella removal but also improving the efficiency of the cooling tower. Before starting, the cooling tower is disinfected using a biocide. While onsite, the cleaning team pressure-washes all hard surfaces, including the cooling tower's hot deck and sump floor.
A descaling agent is applied to the plastic cooling tower fill to dissolve mineral scaling. This agent is left on for about 30 minutes to ensure complete dissolution of the scale. Afterward, a specialized nozzle is used to rinse off the descaler, ensuring thorough cleaning without damaging the fill material.
The sump of the cooling tower is cleaned through pressure washing, vacuuming, or a combination of both, depending on the amount of debris present. Once cleaning is complete, a final biocide treatment is applied to eliminate any bacteria dislodged during the cleaning process. Projectile Tube Cleaning provides both the labor and equipment needed for a full-service cooling tower cleaning project.
