Foam & Foam Making Equipment

Introduction

Definition:    Foam is concentration for producing mechanical foam for firefighting.

How is fire stopped by foam?

• A constant foam concentrate is added to the portioner.
• The resulting water/foam concentrate is expanded with air in the foam generator.
• The foam blankets the fuel surface smothering the fire.
• The foam blanket separates the flames/ignition source form the fuel surface.
• The foam cools the fuel and any adjacent metal surfaces.
• The foam blanket suppresses the release of flammable vapors that can mix with air.

    It is produced by mechanically missing a gas or air to a solution of a foam compound (concentrate) in water. The foam produced from the concentrates in this standard are of low expansion (up to 20 times). The low expansion foam concentrates are of the following types:

1. Protein foam (PF) – A foam concentrate that has a hydrolysed protein base with stabilizing additives suitable for Class A and B fires (Dark Brown color).
2. Aqueous Film Forming Foam (AFFF) – A foam concentrate that has a fluorinated surfactant with stabilizing additive and synthetic surfactants foaming agents for Class A and B fires (Reddish Brown color).
3. Film Forming Fluoro-Protein Foam (FFFP) – A foam concentrate that is protein base with one or more fluorinated surfactant additives for Class A and B fires (Clear transparent liquid).
4. Synthetic foam (SF) – a non-Fluoro surfactant base concentrate non-hydrolyzed protein suitable only for Class A fire (Clear transparent liquid).

Foam Characteristics

1. Knock Down – Knockdown is the speed at which foam spreads across the surface of a fuel. Quick knockdown is achieved by allowing the solution contained in the bubbles to spread rapidly across the fuel surface.

2. Heat Resistance – Heat resistance is the ability of a foam bubble to withstand direst flame impingement or contact with elevated temperature surfaces, with little or no destruction to the foam bubble. The heat resistance of a foam blanket is often called “burn back resistance”.

3. Fuel Tolerance – Fuel tolerance is the ability of the foam to enter the fuel and resurface with little or no pickup of fuel within the structure of the bubble. A foam bubble which picks up fuel while submerged would simply carry the fuel to the surface and feed the fire.

4. Vapor Suppression – Vapor suppression is the ability of the foam blanket to suppress flammable vapors and prevent their release. Vapor suppression is necessary to extinguish fires involving flammable liquids and to prevent ignition of unignited flammable liquid spills.

The foam concentrate is of three types:

• Type 1 – To be used with 99% water and 1% concentrate.
• Type 3 – To be used with 97% water and 3% concentrates.
• Type 6 – To be used with 94% water and 6% concentrates.

There are three types of Foam Making Branches as per the flow capacity:

    1.    FB 5X

Material       –        Aluminium alloy.

Foam branch pipe and pick up tube.

Flow rate     –        101 PSI (7 kg/cm²).

Capacity      –        225 ltr per min.

Throw length         18 to 25 mtr.

Expansion ration    7:8

    2.    FB 10X

Material       –        Aluminium alloy.

Foam branch pipe and pick up tube.

Flow rate     –        101 PSI (7 kg/cm²).

Capacity      –        450 ltr per min.

Throw length         20 to 25 mtr.

Expansion ration    1:10

    3.    FB 20X

Material       –        Aluminium alloy.

Foam branch pipe and pick up tube.

Flow rate     –        101 PSI (7 kg/cm²).

Capacity      –        900 ltr per min.

Throw length         20 to 25 mtr.

Expansion ration    1:8

    4.    Inline foam inductor:     The Inline Foam Inductors are designed to feed foam concentrate at a set mixing rate into the hose line. Inductors are placed in the delivery line between the pump and the foam nozzle and can be used for medium and also for heavy foam nozzles. 

            Inline foam inductor 225/450 LPM flow rate, variable induction 0% to 6%. Aluminium body with 2.1/2” instantaneous connections and complete with pickup tube.

    5.    Trolley mounted inductor/monitor:  The water foam monitor of 63 mm and 75 mm size are trolley mounted. The trolley is fabricated out of steel sections and is having four wheels. Low profile design provides low center of gravity for enhanced operational stability. 

            The water supply to the monitor is through instantaneous male connection provided in the manifold. The trolley is fixed with rubber wheels. The trolley can be easily maneuvered by one person. It can cover up to 30 meters of distance.