HIGH EXPANSION FOAM SYSTEM
What is a Hi-Ex Foam System?
The High Expansion Foam System is a foam deluge system that delivers the foam solution, (foam concentrate and water mixture), to a discharge device known as a hi-ex foam generator. Hi-Ex Foam concentrate and water are mixed in the correct proportion by various methods to form a foam solution. This solution flows to the Hi-Ex Foam Generator with a water powered motor then discharged through a nozzle onto a fine mesh stainless steel screen.
What is Fire Fighting Foam?
Fire Fighting Foam is basically a stable mass of small, air-filled bubbles that has a lower density than oil, petrol, or water. It comprises three essential elements:- Foam concentrate, Water & Air .The foam concentrate is injected into the water by means of a foam concentrate proportioning unit, and the resulting blend is fed to a foam generator. In most cases this is located at the end of the pipe or hose that is used to deliver the mixture. The foam generator sucks-in air, which combines with the liquid mixture to create the fire fighting foam.
How Foam Works ?
The foam has a low density, as such the foam readily floats on a fires fuel surface or completely fill the engulfs protected area to extinguish the fire by separating the fuel from the oxygen in what is called total volume filling applications. The foam completely smothers the fire, while its high water content provides effective cooling to reduce the fires heat energy.
Categories of Foam ?
Foam is characterized by the volume of foam.
Low-expansion or Low-Ex foam
- expansion factor of up to 20.
Medium-expansion or Med-Ex foam
- expansion factor between 20 and 200.
High-expansion or Hi-Ex foam
- expansion foam has a factor higher than 200 as high as 1100.
How Hi-Ex Foam Works?
Hi-Ex Foam completely fill and engulfs the area in which the fire has occurred and has a mass effect, effectively isolating the entire fire area and extinguishing a fire in several ways as follows. The water within the foam is turned into steam and contributes towards a rapid cooling of the fire. The steam also acts as an inserting agent and reduces the oxygen content of the air. The isolating characteristic of Hi-Ex Foam prevents heat from spreading and setting other objects alight. Foam also prevents flammable gases from spreading and igniting.
Why use Hi-Ex Foam (HEF) ?
HEF provides total system reliability that insures system operation whenever it is called upon to work... all solid-state supervision makes system totally self-monitoring including motor windings. HEF reduces total site fire protection costs. HEF systems are water-saving systems... they use a minimum amount of water (small volume and very low pressure) to do a maximum job-any water used is used more efficiently. HEF does not destroy product (primarily because of lower water content). HEF limits smoke damage, and because of the detergent properties of the foaming agent, it provides a self-cleaning effect. HEF itself, due to its non-corrosive nature, is easy to clean up... leaving no messy, sticking residue. HEF also, provides a thermal insulating barrier for personnel and product protection. HEF is a volumetric, 3 dimensional fire fighter... it can get around all obstacles and lends itself easily to total flooding or local application.
Hi-Expansion Foam Generator
A High-Expansion Foam generator is main component. It is used to create the Hi-Ex Foam, and this usually incorporates a fan that ensures the required amount of fresh air is available for the foam production. This fan can be driven by a electric motor, engine, or by a water turbine.
Hi-Ex Foam System Application
Aircraft hangars – both civil and military Hazardous waste storage facilities Flammable liquid stores and flammable material production facilities Cable tunnels Turbine generators Paper product and Tyre warehouses Engine test cells Ship holds and Engine rooms Transformer rooms