Every spring we welcome the milder weather, and with it, various plant and animal life. However, not all of nature’s gifts are beneficial to our evaporative cooling systems; especially the outdoor cooling towers that reject heat from our commercial, institutional, and industrial facilities. Late wintry storms can cause ice and snow accumulation. Heavy rain and hail can disrupt the anticipated easing of the harsh environmental conditions of winter.
Cooling towers are essentially large air scrubbers. With the increase of budding life associated with the spring season comes a variety of airborne materials that can be extremely exasperating; causing a disruption of efficient equipment operation. Tree seed formation is a common issue, with cottonwood trees being especially problematic. Seed casings, for instance, can block the inlet air passageways on evaporative cooling towers. Many other forms of pollutant particles, such as insects, pollen, dust from wind storms, nearby construction building projects, expansions to existing structures, and repairs on roads or highways can also present similar problems.
Screens & Physical Barriers
Air is drawn or forced into the water distribution section of cooling towers by fans to facilitate the evaporative heat exchange process, allowing for maximum heat rejection based on designed capacity. To alleviate the condition of reduced flow due to clogging and to prevent costly downtime for cleaning, several companies make protective screens to trap the debris before it enters the cooling tower fill area. While these certainly aid in protection, no equipment is without maintenance requirements. These screens must be cleaned regularly throughout the year, but especially during bloom periods to be kept in good repair. Some other effective types of physical barriers are ornamental fences and walls made of porous materials. Design considerations prior to building can reduce this labor by locating cooling towers away from high potential areas of this type of contamination.
Equipment
Filtration equipment and chemical treatment programs can further help to remove suspended contaminants from the system. Filters are typically utilized as a side stream and equipped with their own designated booster pumps to avoid interrupting the design flow of the cooling tower water. It is a best practice to incorporate a tower basin sweeper jet assembly to reduce accumulation of debris in the sump. Specialty adjunct chemicals like polymeric dispersants and surfactants may be implemented when appropriate to aid in removal of small-size suspended particles and biofilm formations that can attract matter into a sticky slime on metal surfaces.
Maintenance & Cleaning Services
Regularly scheduled cooling tower cleanings and chemical treatments can also help to alleviate the buildup of debris. Normally, towers are cleaned twice per year, spring and fall, in this manner. Mechanical cleaning and disinfection procedures must be employed correctly to address problem areas and prevent damage. Effective cooling tower cleaning and disinfection is a labor-intensive process that requires specialized chemicals, equipment, and expertise. Vigorous cleaning and disinfection procedures using specialized cleaners may be necessary to remove fill deposits and biofilms. Specific protocols may be necessary to accommodate systems that cannot be shut down for cleaning.
Chem-Aqua specializes in complete water treatment solutions; providing custom equipment and chemical treatment methods to properly control airborne contaminants that can often foul these important and costly mechanical systems. Our Chem-Aqua Services team is prepared to manage cleaning and disinfection processes for any cooling system. Contact us or visit our web site at www.chemaqua.com.
Written by: Jerry Angelilli