Foam system
Foam Fire Suppression System Dubai
Foam fire suppression systems are crucial components of fire safety strategies in Dubai, particularly in industries like oil and gas, petrochemicals, aviation, and manufacturing. These systems are designed to effectively suppress fires involving flammable liquids and are highly versatile in their application.
The foam suppression system is made up of foam concentrate, water, and air that mixes to create a blanket of foam that protects the flammable fuel from combusting. The effectiveness of the solution depends on the correct selection of foam concentrates and discharge devices.
The foam blanket’s thin layer prevents oxygen contact from fuel fire to mitigate flammable vapor as well as fire. This makes foam suppression systems an effective option for protecting flammable and combustible liquids.
NFPA 11 contains requirements for foam-water systems, with requirements for foam systems also found in NFPA 13, NFPA 16, NFPA 30, NFPA 409, and NFPA 418.
Variations
Foam Suppression System Variations
Foam fire suppression systems are classified as high, medium, or low expansion; each system delivers a different suppression process based on application areas.
High Expansion Foam System
In a High expansion foam system, thefoam expands from 100:1 to 1000:1, air or other nonflammable gas expands the range naturally or forcefully. This high expansion foam creates an upper depth, less wet blanket with large bubbles. It is very light and can quickly fill an extended enclosure. A small amount of water creates a large amount of foam within a short time and suppresses fire by smothering. A high expansion system is applied to large enclosed areas where a total flooding system is required at any time to extinguish the fire, not suitable for outdoor areas. Mostly used in warehouses, aircraft hangars, and liquefied natural gas impound basins.
Medium Expansion Foam System
In a Medium expansion foam system, the expansion ratio is 10:1 to 100:1, very useful for small surface area. This system can produce a large amount of accurate foam within a short duration. It creates a 2 feet depth thick blanket above the flammable fuels/chemicals and separates fuel from the oxygen. Besides, existing water provides a cooling effect over the fire. Thus, extinguish the fire as well as vapor used in refineries, chemical manufacturing areas, municipal fire brigades, solvent storage areas.
Low Expansion Foam System
In a Low expansion foam system, the foamexpands ratio is 10:1 that creates a very wet foam blanket with high dense small foam bubbles. The foam blanket is quite durable and creates a secure cover. It separates the fuel from oxygen by a smothering process. Additionally, existing adequate water produces a cooling effect over the flame.
Discharges happen through:
• Foam Sprinkler systems
• Foam Spray nozzles
• Foam maker/foam – Chamber/foam pourer
• Foam monitor for external use
• High expansion foam generator
Types of foam concentrate
Various types of foam concentrate exist, in accordance with the application considered. Typical foam concentrate types are the following:
• Aqueous Film-Forming Foam Concentrate (AFFF).
• Film-Forming Fluoroprotein Foam Concentrate (FFFP).
• Alcohol-Resistant Foam Concentrate, used for fighting fires on materials usually destructive to regular AFFF or FFFP foams as well as fires involving hydrocarbons.
• Fluoroprotein Foam Concentrate.
• Synthetic Foam Concentrate.
In general, different types and/or brands of foam concentrates shall not be mixed together.
Extinguishment Process
We know, heat, fuel, oxygen, and chemical reaction burn fire, so we have to cut out any one of the elements to extinguish the fire. Foam systems mainly interfere with oxygen. First, it develops a foam blanket over the flammable fuels, separating the fuels from the oxygen, thus excluding oxygen by smothering.
Then the waters of the solution absorb heats and cool the fuels as well as substance surfaces very fast by cooling effect. Thus, prevent reignition. The foam blankets also suppress the vapors of flammable liquids effectively and dilute the vapor phase concentration.
Foam Suppression System Working Principle
Foam systems consist of storage vessels (Bladder Tanks) with a built-in proportioning device that contains the foam concentrates and is connected into the discharge system ready for immediate use in the event of a fire. Foam Concentrates rapidly knock down fire by producing a thin aqueous film layer. For maximum effectiveness, the exact amount of foam concentrate must be mixed with water.
The leading firefighting agent in a foam fire system is Aqueous Film-Forming Foams (AFFF). It requires a little energy input to generate high-quality firefighting foam. Usually, 1% and 3% foam concentrate used in hydrocarbon fuels fires. If the concentrate container is shown 3% foam concentrate, that’s mean for every 100 gallons of foam solution, 3 gallons of the foam concentrate must be used with the 97 gallons of water in the solution. Proportioning Devices release the proper amount of concentrate into the water supply based on the solution required, and based on a range of flow rates and pressures.
Foam solutions applied to the flammable fire by either aspirating or non-aspirating devices. The air-aspirating device contains air and mixes it with foam solution within the device. Besides, the non-air-aspirating device is incapable of doing it. Foam discharge devices vary depending on application specialties as well as requirements, and this could be sprinkler heads compatible with foams, foam monitors, foam makers, foam chamber, foam generator, handline nozzle and so forth. Foam suppression system operates on a deluge system for fast application of water in the system. The deluge valve is the entire system water control valve that is quick in a release by hydraulically or electrically. Foam deluge system capable of discharge foam and water solution automatically through the discharge device by accurate cross zoning detection system. So, no chance of inaccuracy and false alarm activation in the system.
- Foam fire suppression system is ideal for large areas that need to be filled quickly in case of a fire hazard. The system automatically and constructively extinguishes fire by smothering.
- This system is more effective on hotter fires compared to traditional sprinklers and gives the most significant advantage in preventing massive loss of property.
- The primary specialty of the foam system is the foam blanket that efficiently creates a barrier between fuel and fire.
- It is less toxic, minimal water damage to structure and tools, but not applicable for electrical equipment. Besides, one has to be careful in the cleaning process after suppression.
- If your plant handles flammable liquids or power generating equipment, a foam fire suppression system could be an essential factor in keeping your space safe.
- large and hazardous facilities
- power stations
- Refineries
- Oil, Gas, Chemical & Industrial facilities
- Generator Rooms
- processing areas
- petrochemicals tank farms
- aircraft hangars
- marine applications
- storage facilities
- warehouses
- Similar entities and protect lives