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Foam fire extinguishing system is widely applied in areas with high fire and explosion risk such as petrol tanks, chemical storage, etc., because of its great advantages such as reducing the amount of fire extinguishing agent needed to extinguish the fire. turn off the fire; reduce equipment damage; reducing environmental pollution,…
A foam fire suppression system, when activated, releases a foam that covers the surface of gasoline, separating the flammable liquid from the air and fire, thereby extinguishing the fire.
Due to its effective nature and also because it reduces the amount of water required, foam systems are now widely used. Reducing the amount of extinguishing agent needed to extinguish the fire, which means minimizing damage to equipment and utensils, and reducing environmental pollution caused by water spray, especially in places where hazardous substances are contained.
For high expansion foam, there is almost no damage to the goods, and in a short time, the whole warehouse is back to normal.
Foam systems for use in particularly high risk of fire and explosion have been carefully selected, requiring appropriate equipment such as foam concentrates, foam mixing systems, foaming devices, and effective coordination between these parts in a fire fighting system.
Foam concentrate is an antagonist to gasoline. Although it shares the same standards, however, each type of foam - protein and fluoroprotein - has its own characteristics, suitable or less suitable application for a particular site.
The foam nozzle can be a sprinkler, spray, nozzle, monitor, foam pourer, or high expantion foam generator, depending on the foam system used.
Principle of Fire Fighting
Depending on the type of foam, foam can fight fires in many ways:
Either use foam to cover the surface of the flammable substance with a thick layer of foam, extinguishing the flame and isolating the fuel to prevent further contact with the air, or cooling the fuel with the amount of water contained in the foam. , or a cover that prevents the liquid (fuel) from evaporating and mixing with the air.
What is Foam Fire Extinguisher?
Simply put, firefighting foam is a dense, durable, air-filled foam that has a lower density than oil, gasoline, or water.
Foam is created by 3 components: water, foam concentrate, and air. Water is mixed with foam concentrate, forming a foam solution. This solution is again mixed with air (air suction) to create a fire-fighting foam with enough features, ready to spray on the surface of the inflammable object and extinguish the fire.
Foam Foam Classification:
Foam foam can be classified according to its expansion or fire resistance, specifically as follows:
Classification of Foam Foam According to Expansion
Low expansion foam like AFFF has an expansion rate of less than 20 times, has a low viscosity, can quickly cover large areas.
Medium expansion foam foam has an expansion rate of 20 to 100 times.
High Expansion Foam has an expansion rate of 200 to 1000 times, making it suitable for enclosed spaces such as hangars where a rapid coverage rate is required.
Alcohol-resistant foam contains a polymer that forms a protective layer between the burning surface and the foam, preventing decomposition of the foam by alcohol in the burning fuel. Alcohol-resistant foam is used in the extinguishing of oxygen-containing fuels, such as MTBE.
Classification of Foam Foam According to Fire Resistance
When classified according to fire resistance, Foam foam is divided into class A and B foam.
+ Foam Grade A
Class A foam was developed in the mid-1980s for the purpose of fighting forest fires. Class A Foam reduces the surface tension of the water, helping to wet and saturate the Class A fuel with water. This aids in fire suppression and can prevent the fire from spreading.
+ Foam Foam Remover
Class B Foam is manufactured to resist Class B fires (flammable liquids). Using Class A foam to fight Class B fires may not be as effective as Class A foams are not designed to cover smoke produced by flammable liquids. Class B foam has 2 main types:
+ Synthetic Foam
Synthetic foam based on synthetic surfactants. They have a better ability to expand and can spread over the surface of the liquid helping to extinguish the flame faster. There are two types of synthetic foam: AFFF Foam and alcohol-resistant AR-AFFF Foam.
+ Foam Protein Foam
Foam Protein Foam contains natural protein as the foaming agent. Unlike synthetic foam, Protein Foam is biodegradable. They flow and propagate more slowly, but provide a coating that is more heat resistant and more durable.