Technical solutions of achieving the fire-extinguishing foam

Technical solutions of achieving the fire-extinguishing foam

The installations components of the fire extinguishing with foam:

In terms of making the fire extinguishing installations with foam, are:

  • fixed;
  • semifixed;
  • mobile.

Fixed installations of firefighting with foam consist mainly of:

  • Water supply installations;
  • foaming containers;
  • generating foam air jet;
  • dispensers;
  • sparkling pumps;
  • pipe for foaming solution;
  • foam overflow.

Semifixed installations of fighting fire with foam have in their composition and dosing tanks sparkling phones.

Heads of overflow foam and pipes foam (or foaming solution) are fixed.

Mobile installations consist only of transportable elements.

The foam is inserted in burned tanks at their top or bottom. It is recommended that the foam layer to be inserted above the water might accumulated in the liquid fuel tank.

The introduction of the foam at the bottom of the tank can be used only at cylindrical tanks, fixed roof, the stored hydrocarbons. in some cases, based on a thorough analysis it can be applied to floating roof tanks.

The advantages of introducing the foam on the bottom of the tank are:

  • all of the foam reaches to the liquid surface, forming the layer extinction;
  • increased resistance of the system of damage produced by explosions and fires;
  • cooling of the surface layers after layers drive the bottom.

The introduction the foam on the bottom of the tank is not effective for petroleum products kinematic viscosity greater than 4.40 m2 / s (Low temperature storage).

Foam extinguishing installation provided with sectioning valves, rupture membranes properly sized for pressure tank and valve check valve (which prevents fuel spillage in the foam production installation).

We recommend installation of filters on water pipelines, upstream of the dispenser.

RISKS

In general, the foam does not present major risks to humans.

Some foams may present environmental risk.

The foam concentrated after dilution with water at recommended concentration for normal use, should not pose a toxic risk to life, relative to the environment.

The central building of foam must meet the following main conditions:

  • to be made of non-combustible fire resistant, suitable to the II degree of fire resistance;
  • walls protected from the tanks have only slits (visors) with span of 0.20 x 0.10 m, made so that they are be able to monitor the evolution of fire protection tanks;
  • floor to be the slope to allow water to drain outside;
  • to ensure the storage pools of sparkling concentrated in specific conditions of each product;
  • to be provided with electric lighting installation for further work in case of damage, executed in accordance with the norm I 7;
  • allowing the access and supply of foam concentrate;
  • to have provided reliable means of communication with the fire service, the pumping station for fire control room etc..

The preparation of the central installations in the sparkling solution and ductwork shall be provided with connections and valves for flushing with water after use.

Starting the pump and opening of valve on pipe foaming solution can be manual, local or remote, and automatic fire from special detectors. Automatic start remotely and must be doubled by a manually starting.

The fixed extinguisher installations with foam are provided with a backup pump. Power supply pumps ensure two independent sources (two power sources, a power source and a source of another nature (thermal, pneumatic, steam, etc..) Or two heat sources.

On the main distributor are installed nozzles with valves and fittings B for introducing the sparkling solution and special vehicles directly from the intervention (for fixed pump failure).

When a foam preparation installation serves several objects from the main dealer, individual pipes are provided to each subject matter or annular pipe network.

To all major hubs providing foam solution they are prevaid with manual closing valves pipes and pipe fittings type B for portable power generating foam or mechanical foam cannons.