Special risks installation (fire protection by foam or deluge)

Fire protection by foam

Video installation mousse Foam extinction test

AAI also makes fire protection systems equipped with foam generators.
 

These fire protection installations are generally suited to the storage of inflammable liquids for which water alone is ineffective.

One characteristic of this type of fire protection is expansion:

“ratio between the volume of foam produced and that of the foam solution used” – excerpt from the rule APSAD R12 of May 1999.

Example of expansion: with 1 m³ of foam solution, a coefficient of expansion of 200 allows 200m³ of foam to be obtained.

  • Low expansion: coefficient of expansion lower than 20 obtained using sprinkler heads or specific nozzles. Appropriate to both indoor and outdoor extinction.
  • Medium expansion: coefficient of expansion between 20 and 200 obtained with foam generators. Used outdoors and indoors when the behaviour in combustion is not fully known.
  • High expansion: coefficient of expansion greater than 200 obtained using several foam generators. Suited for extinctions in enclosed spaces.

This foam extinction system requires a source of water. Injection of the foam compound into the water network can be achieved in a number of ways: feed pumps, proportioners and injectors. The volume of the foam compound reserve is calculated in relation to the flow of water and the desired application time. This foaming solution (water+ foam compound) will turn into foam as it goes through the generator (air injected).

An automatic foam extinction installation ensures detection and alarm functions and allows fires of inflammable liquids in enclosed spaces (for high expansion: solution rich in air) or open spaces (low or medium expansion: solution rich in water) to be extinguished.
The foam, which is generated rapidly, acts mainly by choking the fire, blocking the vapours and preventing them from being spread into the atmosphere.