The Burgo Verzuolo mill in Italy was able to radically improve the energy efficiency and controllability of the vacuum system in a rebuild of its PM 9.
Vacuum system optimization detects energy efficiency losses
The main weakness of a traditionally designed liquid ring pump (LRP) vacuum system is its poor energy efficiency under varying operating conditions.
When Burgo Verzuolo mill decided to improve the runnability of PM 9 and ensure the potential for energy savings, Valmet’s team carried out several process improvement studies, including a vacuum system energy efficiency survey. The air flows were measured and the system efficiency losses were estimated to be over 1 MW.
Based on the results, the mill decided to rebuild PM 9, and the vacuum system improvement was implemented in two phases: first by modifying the existing vacuum controls and pump connections and secondly by applying new variable speed drives in the vacuum system. The existing LRP system of PM 9 was modified with Valmet’s new vacuum system concept during a two-day shutdown.
Satisfied start-up group after the successful vacuum system improvement.
Summary
Location
Verzuolo, Italy
Customer target
Improve the runnability of the machine and ascertain the potential for energy savings.
Solution
Burgo Verzuolo and Valmet signed a cooperation agreement including several process improvement studies. The mill decided to rebuild PM 9’s vacuum system in two stages.
Results
Energy savings of 775 kW were immediately achieved and the potential overall savings after the optimization were estimated to be over 1 MW.
