Situation description
Situation description
The Metso/Valmet CFB boiler, started up 2010, has steam data 45 kg/s, 60 bar, 475°C. It produces 45 MW electricity and delivers steam to the paper machines and heat to a nearby plant. The fuel that is used is mainly RDF (60 %) but also untreated wood, municipal waste, and some sewage sludge (up to 60 tons/day). The economizer is equipped with six explosion generators, three acoustic horns (audible frequency) and six steam sootblowers. The steam sootblowers are operated once a day.
The horns and the explosion generators are operated every few minutes. Although these cleaning systems were used, the economizer accumulated a blockage during the year, with high differential pressure and a need for manual removal/brushing away the lumps/blockages.
