GENERAL INFORMATION ON FOAM EXTINGUISHING TECHNOLOGIES
In late 1990s and early 2000s, new foam fire extinguishing technologies based on modern film-forming foam concentrates (AFFF, AFFF/AR, FFFP, etc.) began spreading in Russia. The very principle of eliminating combustion of flammable liquids has changed. Instead of isolating the fuel phase from atmospheric oxygen with a layer of medium-expansion foam, the insulation with a thin film of a foam concentrate solution, which is released from low-expansion foam concentrate, has been adopted.
The principle of eliminating combustion with medium-expansion foam with synthetic hydrocarbon foam concentrates of S type
The principle of eliminating combustion with low-expansion foam with synthetic fluorine-containing film-forming foam concentrates such as AFFF, AFFF/AR and AFFF/AR-LV
This reduces the time to extinguish fires and virtually eliminates the passage of oil vapor or oil products released from the heated layers of liquids through the layers of the foam concentrate and foam after the elimination of combustion. Thereby, the problem of burnback has been solved and the probability of contact of flammable liquids vapors with red-hot metal structures and explosions has been reduced. It has become possible to effectively use foam fire extinguishing installations to prevent fires and explosions in case of oil or oil product spills. A previously impossible method for subsurface suppression of flammable liquids has appeared. In other words, saying without exaggeration, the advent of new types of foam concentrates has brought a scientific and technological revolution in foam firefighting.
The creation of our Company in 2004 was due precisely to the emergence and development in Russia of innovative foam firefighting technologies, and therefore we orient our partners to modern types of foam concentrates and offer a whole range of firefighting equipment for the implementation of new foam firefighting technologies based thereon.
The advantages of new foam firefighting technologies are shown in the table below, as developed on the basis of GOST R 50588-2012.
|Compared indicators||Traditional foam fire extinguishing technologies||Modern foam fire extinguishing technologies|
|Type of foam concentrate and the expansion ratio of applied foam||synthetic hydrocarbon foam concentrate, medium-expansion foam||film-forming foam concentrate, low-expansion foam|
|Extinguishing principle||insulation of fuel phase from air with medium-expansion foam||insulation of fuel phase from air with a thin insulating film released from the foam concentrate solution|
|Extinguishing time of a conventional fire according to GOST R 50588-2012, s, max||300||120|
|Burnback time*, s, min||not standardized||330|
|Allowed to use to prevent explosions and fires of spills||practically absent (limited to a few minutes)||direct use (isolates fuel for up to 2-3 hours)|
|Spreadability on the surface of a combustible liquid||is not standardized||specified in GOST R 53280.2‑2010|
* The time indicator that the fuel phase is isolated from the air after putting out the fire. It characterizes the foam ability to prevent the passage of fuel phase vapor released from the heated layers after the elimination of combustion.
Extinguishing of n-heptane in the model fire source with various types of foam concentrates
Extinguishing with a medium-expansion foam of synthetic hydrocarbon foam concentrates of the S type
Extinguishing with low-expansion foam with synthetic fluorine-containing film-forming foam concentrates of the following types AFFF, AFFF/AR and AFFF/AR-LV
Burning of the model fire source
Extinguishing a model fire source
Model fire source extinguished
Protection against burnback
At about the same time, another new fire extinguishing method has appeared. The cubical fire extinguishing (by volume) with high-expansion foam significantly exceeds in all respects the volume fire extinguishing with medium-expansion foam. Suffice it to say that the foam expansion ratio of GPS-type generators is up to 100, and that of Favorit high-expansion foam generators reaches 800. At the same time, the use of film-forming foam concentrates is not required, since the principle of eliminating fire is to create a layer of high-expansion foam that fills the entire protected volume and does not support the combustion process.
Extinguishing by volume principle
In this case, the use of conventional synthetic foam concentrates is sufficient, and the novelty lies in the use of a new type equipment - ejection generators of high-expansion foam (GHPE).
High-expansion foam applied by a foam generator of the GHPE type
The new extinguishing principles have been confirmed by Russian and foreign researchers and adopted as international standards and regulatory framework of the Russian Federation. Today, technologies based on the use of film-forming foam concentrates are the priority for creating fire protection systems.
Along with new technologies, many facilities provide for traditional extinguishing methods in terms of area and volume with medium-expansion foam, which is also allowed by the regulatory documents of the Russian Federation. This is due to a large number of fire protection systems based on synthetic hydrocarbon foam concentrates created in previous years at various industrial facilities. Although in some cases the use of this method remains quite effective, the basis of such systems is foam fire extinguishing installations with an extensive network of solution pipelines. While expanding existing fire protection systems, the Pozhneftehim Group recommends considering the possibility of a phased reconstruction with the transition to new effective types of foam concentrates and related firefighting equipment. The main approaches to solving these problems are reflected in the presentation “Recommendations for the phased reconstruction of foam fire extinguishing systems (installations) with the transition to modern foam firefighting technologies”.
The Pozhneftehim Group offers a wide range of Aquafoam foam concentrates and wetting agents. The choice of the type of foam concentrate and its properties is one of the key issues in creating effective fire protection systems. Possible solutions to this issue are reflected in the presentation "Recommendations on the selection of the type and properties of foam concentrate in the design of fire extinguishing systems (installations)".
If you have any difficulties or questions when selecting foam fire extinguishing methods, types of foam concentrates and their properties, contact our specialists.