Machinery and technology part
The SAFED is a stabile fire-extinguishing device (SFED) determined for use in traffic tunnels especially. The SAFED is fully compatible with mobile pumping units of the Fire-extinguishing and Rescue Corps. The fire-extinguishing device based on water mist as the part of the SAFED sufficiently suppresses fire by means of absorbing the energy released from the fire and provides inertial effect, so the SAFED uses it mainly in the main tunnel pipes. To improve the water mist efficiency or limiting the fire spread in main tunnel pipes the SAFED uses fire-extinguishing technical device of water screens installed by the beginning and end of every fire-extinguishing section in main tunnel pipes. The fire-extinguishing technical device as a sprinkler system of fire-extinguishing using water is not sufficient for efficient fire-extinguishing in semi-closed spaces such as main tunnel pipes or main underground traffic systems. Because of the above, the SAFED uses the sprinkler system of fire-extinguishing only outside the main tunnel pipes e.g. connecting parts of the tunnel pipes separated from the main tunnel pipe (system with a pair of doors linked transversally).
The fire-extinguishing technical device based on water mist consists of three main mechanisms:
- oxygen withdrawal (inertization),
- radiant heat blocking.
The efficiency of cooling and inertization depends on evaporation from the surface area, whereas the efficiency of radiant heat blocking depends mainly on the number of drops. When the surface area and the number of drops considering the volume of water – fire-extinguishing medium - is big, all three mechanisms are optimised by small drop sizes.
One of the most important features of water as a suppressing material is its cooling capacity. Water evaporation may absorb energy over 2 MJ/kg, which is better than any suppressing material we could imagine. Due to very high speed of evaporation, cooling within the fire site is immediate. Evaporation takes place just at the point, where the hot flames and fire evaporation may cause effect. Constant air flow during the activation process cools the water evaporated and no harm for humans may be recorded.
The technical solution of the active fire prevention in tunnels TUFEPRO®, by means of the SAFED is designed for the situation in a tunnel consisting of one or two tunnel pipes with the existence of several extinguishing sections. In the case of double pipe the transversal connections of individual pipes are linked by connecting tunnels. Every tunnel is equipped by its own machinery room with a water pump and water tank for extinguishing.
The electrical part of the SAFED system covers all the requirements on supplying the SAFED system, fire detection /localisation and SAFED system and all its components management.
Fire signalling and localisation
The system of electric fire alarm and fire localisation is solved by means of electronic fire alarm with an independent central office, whereas in every section the fire must be confirmed by two independent fire detectors. The fire central office will be addressable just as all the fire detectors and buttons.
SAFED complies with the criteria of the technical protocol TP 099 issued by the Ministry of Transport, Construction and Regional Development of the Slovak Republic.
TUFEPRO® module is an expert modular solution providing for complex administration, operation and diagnostics of the SAFED system.