What Are The Advantages And Disadvantages Of Foam Fire Extinguishing?

Advantages and disadvantages of liquid injection systems:
1. The liquid spray foam fire extinguishing system has the advantages of simple structure, convenient installation and maintenance, easy debugging and various types of foam liquid can be applied.
2. The disadvantage of liquid spraying is that the foam generator and some pipelines are easily damaged by the combustion and explosion of the storage tank and lose their effect. The system is mainly suitable for above-ground fixed top vertical oil tanks, floating roof tanks and Class A, B and C liquid storage tanks in oil depots.

Advantages and disadvantages of subsump injection systems:
1. When spraying under liquid, the nozzle is limited by pressure, in order to ensure the quality of fire extinguishing, a high back pressure foam generator must be used.
2. The disadvantage is that submerged injection can only be used for non-water-soluble liquid fire, otherwise, it will affect the quality of foam and affect the fire extinguishing effect. Moreover, the spout is prone to corrosion. Submerged spray foam systems are only suitable for above-ground fixed roof storage tanks for non-water-soluble Class A, B and C liquids. It is not suitable for water-soluble A, B and C liquid storage tanks, nor is it suitable for external floating roof and inner floating roof storage tanks.
3. The advantage of submersible injection is that the bottom of the tank explosion is generally not easy to be damaged, which improves the safety of the submerged foam system and also improves the effective reserve of the tank. When extinguishing the fire, the foam reaches the liquid level of combustion through the liquid subordinate, and does not pass the high-temperature flame, which reduces the loss of the foam and improves the fire extinguishing effect. When the foam floats from the lower part of the tank to the burning liquid surface, the cold oil below the tank and the hot oil above produce convection, which plays a cooling role and is conducive to fire extinguishing. And there is no special foam pipeline, saving investment.
In general, low-power foam fire extinguishing systems should be used to fight flammable liquid fires. The so-called low-power foam refers to air foam with a foaming power of less than 20 times.

Advantages and disadvantages of low power foam fire extinguishing system:
(1) The foam foam of the system has a small foaming multiple and a large foam density, so the foam basically does not rise with the hot air flow generated by combustion, which is suitable for fighting combustible liquid fires;
(2) The foam injection is far away, and the effective height of the spray is also large, which is suitable for mobile foam fire extinguishing system.