Mechanical draft cooling towers are critical fixed assets that need to be maintained and remain in service in order to cool various plant operations and systems. Essentially, the cooling tower basin in mechanical draft technology serves a two-fold purpose, one as containment for the cooling water and two as the foundation for supporting overlaying "fill" structures. Almost all of these basin structures are constructed of conventionally reinforced concrete, either partially or totally placed below grade. Their service environment subjects them to various aggressive deterioration mechanisms including embedded metal corrosion, original construction defects, environmental degradation (i.e. freeze-thaw, algae growth, etc.) as well as chemical attack resulting in erosion and structural section loss. Since these structures contain process water and function as support foundations, the existing condition of these structures should be evaluated regularly and repairs performed should conditions warrant, on a timely basis. Evaluation techniques exist, both non-destructive (NDT) and semi-destructive (SDT), which can serve as tools in assessing in-site conditions, either on or offline. Additionally, the paper will highlight case histories of cooling tower basin evaluations and subsequent repair program implementation.
09-08: Cooling Tower Basin Evaluation and Repair
Tom Kline, Structural Preservation Systems