Valmet develops new online ash analyzer  

Valmet Recovery Ash Analyzer. Image courtesy: Valmet

Valmet has developed an innovative solution to reduce forced boiler shutdowns, caused by superheater corrosion or boiler plugging, and provide guidance for ash treatment and sootblowing need. The new Valmet Recovery Ash Analyzer measures the ash composition at the electrostatic precipitator (ESP) and determines the ash melting temperatures which describe the corrosiveness and stickiness of ash.

A new Valmet Industrial Internet (VII) application, Valmet Ash Balance Advisor, is an additional option to maximize the Valmet Recovery Ash Analyzer’s advantages and optimize ash treatment for significant cost savings in sodium make-up. Operators are provided with an online view of ash balance and boiler operation with real-time indicators of fouling and corrosion risks, which helps to achieve cost-effective ash treatment amount or dump volume.

Until now, ash treatment has typically been a batch operation based on infrequent laboratory tests with no standard criteria of when to start treating or dumping ash.

"The problem with laboratory measurements is that samples are taken so seldom, and the results are often incomplete and cannot be used for optimal control. Now, with the online analyzer, control of actual ash chemistry is possible and boiler cleaning together with operational costs can be optimized on a continuous basis," says Timo Laurila, Business Manager, Recovery Analyzers and Advanced Process Controls, Automation, Valmet.

The Valmet Recovery Ash Analyzer measures the complete chemical balance including ESP ash pH, carbonate (CO3), sulfate (SO4), chloride (Cl), potassium (K) and sodium (Na) concentrations as well as calculating ash melting temperatures T0, T15 and T70. The ESP ash sample is taken from the ash drop shoot after the ash conveyor by a robust stainless-steel sampler, dissolved in water, and transferred to the analyzer where chemical analyses and ash melting temperature calculations are made. Comprehensive diagnostics and secure Valmet Industrial Internet (VII) ready capabilities ensure reliable and dependable results with intuitive access to measurement operation and remote services from Valmet.