Cooling tower fill fouling control in a geothermal power plant

Since its first introduction to the market in the 1970s, cooling tower film fill technology has significantly increased thermal performance and reduced the size of cooling towers. However, the narrow spaces between film fill sheets make them more susceptible to fouling. Without proper chemical treatment, deposits can accumulate within the film fill resulting in reduced tower efficiency, increased fouling and plugging of the fill. These phenomena could eventually lead to collapse of the tower structure. This paper describes a new approach to remedy the high efficiency film fill fouling problem in a geothermal power plant. The plant has a long history of fill fouling problems due to complex make-up water chemistry and desert-related environmental conditions. In recent years, various biocide and biodispersant treatments have significantly improved fouling control by slowing down tower fill deposition rates. However, no program has been successful in reducing fill weight gain, especially during the summer months. Within six weeks after starting a new control program, the average weight of the tower fill deposits dropped 22% and thermal performance of the cooling tower increased 20%. The treatment resulted in significant improvements in cooling tower operation and power generation efficiency.