Safe operations, reliable processes and controlling costs were key goals of this plant. However, the plant’s ability to meet those goals was being compromised by an inadequate water treatment program. This led to heavy fouling of a critical heat exchanger. To maintain the required heat transfer efficiency, this critical exchanger required cleaning and/or replacement every year. Even with these actions, the exchanger’s U coefficient dropped quickly, 2 months after cleaning or replacement. The plant knew something had to change and Nalco was asked to survey the site.
The Nalco team completed a mechanical, operational and chemical survey of plant operations. All parameters were analyzed to fully understand the factors contributing to the fouling problem. It was determined that the competitor’s phosphate-based program was not designed to provide adequate protection at the heat exchanger’s design skin temperatures of 120°F. The supplier’s controller did not allow for adjustments in chemical feed due to changing conditions, nor did it track or trend data. The plant felt it would be advantageous to understand the effects of operational and production changes on their system. Knowing what events are causing performance changes provides more information, which in turn would help the team facilitate sound operational decision, resulting in reliable and efficient operations.
The Nalco team completely redesigned the water treatment program and implemented best practices to ensure system performance. With the goals of increasing heat exchanger performance and reducing operation costs, the plant converted to Nalco’s 3D TRASAR technology. 3D TRASAR technology is a unique combination of innovative chemistry, monitoring and automated control that allows for continuous and direct measurement of the leading indicators of scale, corrosion and fouling. It detects upset conditions and takes appropriate correction actions before they become problematic. It also utilized Nalco’s PSO chemistry, which provides cathodic corrosion protection without the concerns of reversion to orthophosphate.