Unusual Italian Tunnel Ventilation Contract 

Application page: Tunnels and Metros

Product page: Axial Fans

For more information contact:
  
Alan Butcher
Tunnelling Director
tel. +44 1206 222 555
alan.butcher@flaktwoods.com

Fläkt Woods has been awarded the contract to supply the ventilation solutions on the Valsassina Tunnel which connects the Italian city of Lecco to the Valsassina valley.

The mixed type ventilation system consists of two large ventilation rooms (called Lecco and Bione) and 67 of the Company’s Jet Thrust Fans, constructed in stainless steel and certified for operation in emergency situations at 400°C for a maximum of two hours. The fans are positioned over the tunnel entrances, along the side roads and near to the slipways.

The two ventilation rooms are connected to a duct made up of a false ceiling which runs along a good part of the tunnel. Inside this duct special dampers have been installed, constructed in stainless steel AISI316L and fitted with modular type electro-hydraulic actuators which regulate the opening and closing position of the dampers.

The peculiarity of this system is the Bione ventilation room, which contrary to the majority of road tunnel ventilation rooms, is not designed on a horizontal plane but vertical. The room occupies a total of four floors and starts at the level of the false ceiling where the ducts are situated, separated for fresh air intake and polluted air extraction.

Serving these ducts are 4 Fläkt Woods unidirectional Aerofoil JM fans with an impeller diameter of 1600 mm, two for each fresh air duct, and two large two stage JM Aerofoils with an impeller diameter of 2500 mm for the extraction of polluted air. The fans are vertically mounted.