We provide the right extinguishant for all ranges of
application.
Water
Water is mainly used for
fighting fire classification A fires (glowing substances).
The extinguishing effect of water is mainly
based on its heat binding capability. The cooling effect of water disturbs the
prerequisites of a thermal reaction and hinders further processing of
inflammable substances, so that the formation of inflammable gases and vapours
is interrupted. Thus, water extinguishes by cooling.
Extinguishing foam and aqueous
solutions
Extinguishing foam is a highly effective mixture of water,
foaming agent and air.
A stable foaming agent percentage is added to
the water flow with admixture devices. The produced mixture is foamed with air
in subsequent foam generators. The foaming degree depends on the capacity of
the used foam generator, the foaming agent and the foaming agent admixture
rate. In case of a low air intake a wet, heavy extinguishing foam is produced
(low expansion foam). If the air percentage is increased, the foam becomes
drier and thus lighter (medium and high expansion foam).
The air foam utilizes different extinguishing
effects: cooling, suffocating, separating, covering, restraining and displacing
- each one alone or together with others they provide a quick extinguishing
success.
Film forming foam compounds were developed for
fighting fire classification A and B fires. In fire classification A high
extinguishing efficiency is achieved with the combination of the cooling effect
of water and a high net effect of the AFFF part. In case of liquid fires a very
thin sliding film is formed on the burning liquid, which gives the foam
excellent flow properties and protects the combustion area from further oxygen
supply.
Inert gases
The extinguishing effect
of argon, nitrogen and carbon dioxide is achieved by displacing atmospheric
oxygen. This is called the suffocation effect, which occurs if the value
necessary for combustion falls below the specific limit value. In most cases
the fire is already extinguished in case of an oxygen decrease to 13.8 vol.%.
For this the existing air volume must only be displaced by approx. 1/3,
corresponding to an extinguishing gas concentration of 34 vol.%.
Incendiary matters (e.g. acetylene, carbon
monoxide and hydrogen), requiring considerable less oxygen for combustion,
require an increase of the extinguishing gas concentration. The extinguishing
gases argon and carbon dioxide enter the flooding area very quickly and
thoroughly because they are heavier than the ambient air.
Argon (Ar)
is a noble gas obtained
from the ambient air. 0.93 vol.% argon is included in the atmosphere. Its
density in relation to the air is 1.38:1. Being gaseously compressed the
extinguishant argon is stored in high-pressure steel cylinders. The maximum
operating pressure is 300 bar. Argon is not toxic. But during the building-up
of the gas concentration necessary for the extinguishing success, a dangerous
situation may arise from the fire gases and an oxygen deficiency, especially
together with a fire.
Nitrogen (N2)
is a colourless, inodorous and tasteless
gas, which is included in the atmosphere at 78.1 vol.%. Its density in relation
to the air is 0.967:1. Being gaseously compressed the extinguishant nitrogen is
stored in high-pressure steel cylinders. At the moment the maximum operating
pressure is 200 bar at an ambient temperature of +15 °C. Nitrogen is also
not toxic, but as for argon a dangerous situation may arise from fire gases and
oxygen deficiency.
Carbon dioxide (CO2)
0.03 vol.% carbon dioxide is included in
the atmosphere. Its density in relation to the air is 1.53:1. Being liquefied
under pressure the extinguishant carbon dioxide is stored in high-pressure
steel cylinders (operating pressure at 20 °C: 57 bar) or large low pressure
vessels (-20 °C: 20 bar). Due to the liquid storage a significantly larger
extinguishant quantity can be stored requiring less space. Unlike argon, high
carbon dioxide concentrations are unhealthy. Therefore the trade associations
require special protection measures if a limit value of more than 5 vol.% is
exceeded (BGR 134).
Due to its physical characteristics CO2 is the
only extinguishing gas, which is also used in hand fire extinguishers.
Extinguishing powder
Extinguishing
powders are highly effective and fast extinguishants. The sudden extinguishing
effect of the powder cloud is caused by the suffocation effect and the, so
called, anticatalytic effect, a chemical intervention into the combustion
process. The formation of melting layers on glowing incendiary matters prevents
the diffusion of atmospheric oxygen and the heat-up of immediate fire
surroundings. Reinflammations are not possible. Extinguishing powders mainly
consist of non-poisonous inorganic salts mixed with waterproofing and pouring
agents.
Extinguishing gas Novec™ 1230
The synthetic extinguishing agent 3M™ Novec™ 1230 fire protection fluid is the environmentally compatible alternative. In comparison with chemical extinguishants used so far it has the lowest global warming potential, the shortest atmospheric lifetime and no impact at all on the ozone layer. These positive environmental properties promise above all unlimited use of this extinguishant also in the future.
Novec™ 1230 fluid is neither corrosive nor electrically conductive and causes no damage or residue on sensitive components. It is colourless and essentially odourless as well as liquid at room temperature. The molecules consist of carbon, fluorine and oxygen.
Extinguishing gas HFC-227ea
is an electrically non-conductive odourless and colourless gas. It is stored liquid and under pressure and dispensed into the protected room as a colourless vapour that is clear. HFC-227ea leaves not residue and is well suitable for occupied spaces, since it is harmless for persons at design concentration.
HFC-227ea has the ODP value 0, i.e. it does not reduce stratospheric ozone. The short atmospheric durability of HFC-227ea results from its relatively fast natural degradation.
Send
a request for more information on 'Extinguishants'
|
