Preventing Turbine Corrosion and Scaling Case Study
Case Study

Preventing Turbine Corrosion and Scaling

Case Study

Controlling Sodium and Silica Levels in Cogeneration Power Plants to Protect Turbines

Preventing Turbine Corrosion and Scaling Case Study
Preventing Turbine Corrosion and Scaling Case Study

This case study explains how a major sugar company in Brazil, who supplies the country's electricity grid with 1.5 million MWh from cogeneration, is preventing turbine corrosion and scaling through stringent measurement and control of sodium and silica levels. Minimizing downtime to repair corrosion and clean deposition from turbines is crucial to cogen efficiency, so the company maintains tight control of water and steam condensate quality. Determining contamination at low ppb levels requires highly capable equipment. 

In order to ensure dependable sodium and silica measurement, the cogen power plant installed a METTLER TOLEDO 2300Na Sodium Analyzer and a 2800Si Silica Analyzer. These analyzers combine industry-proven technology with innovative design to provide assurance of water purity in power cycle chemistry applications. The 2300Na Analyzer determines sodium levels by first conditioning the sample to prevent hydrogen ion interference by controlling the input flow and the pH, then uses a sodium ion-selective sensor to precisely determine sodium levels.

For silica determination, METTLER TOLEDO has replaced the 2800Si Analyzer with the next generation 2850Si Silica Analyzer, uniquely combining a proven measurement methodology with value-driven innovation. The 2850Si Analyzer offers reliable and accurate on-line, trace-level measurement of silica and can also verify proper phosphate levels in your water stream.

Like the 2850Si Analyzer, our previous model 2800Si, which was installed at the sugar company, employed the colorimetric method, which involves adding reagents and then measuring the color change in the sample. The analyzers feature automatic zeroing before each measurement, plus automatic sample conditioning and calibration.

Our customer was very impressed by the analyzers’ measurement accuracy and they are more than satisfied with their low maintenance requirement, which frees technicians from routine maintenance. The sensitivity and reliability of the sodium and silica analyzers are providing assurance that their turbines are thoroughly protected, effectively preventing turbine corrosion and scaling for this cogeneration power plant.

Learn more about the 2300Na and the 2850Si at:

  • 2300Na Sodium Analyzer – Reliable on-line silica measurement for pure water treatment and power cycle chemistry applications. Reagent addition confirmation by pH Check ensures consistent measurement results.

  • 2850Si Silica Analyzer  – Early detection of trace sodium and phosphate contamination with minimal operator intervention. Fully automatic, unattended calibration provides excellent repeatability and saves operator time.