Estinguishing medimn used: |
TYPES OF EXTNIGUISHER
|
Water
|
Chemical foam
|
Mechanical foam
|
Powder
|
Carbon dioxide
|
Halogenated hydrocarbons
|
Water, with possible salts in solution |
Basic water solution |
Basic water solution with foam
generating substances |
Water
solution containing foam generating sub-stances |
Dry chemical powders |
Tressurized carbon dioside |
Halogenated hydrocarbons |
Espellant charge of the
extinguisher(stored pressure or cartridge as indicated): |
One basic and one acid reagent; in
general the basic reagent is a solution of sodium bicarbonate and the acid
reagent is a solution of sulphuric or hydrochloric acid or of aluminium
sulphate |
Carbon
dioxide or other pressurized inert gases or compressed air (storage pressure
or separate cartridge) |
Solution of sulphuric of hydrochloric acid or aluminium
sulphate |
Water
solution and acid reagent (e.g. solution of aluminium sulphate) |
Carbon dioxide or other
pressurized inert gases or compressed air (stored pressure or separate
cartridge) |
Carbon
dioxide or other inert gases or dry air (stored pressure or separate
cartridge) |
|
|
The discharge of the extinguisher is achieved by: |
Opening of the valve. Generation of carbon dioxide
(chemical reaction which develops inside the extinguisher) |
Opening of the valve. Action of
pressurized gas (opening of the cartridge) |
Opening of the valve. Generation of carbon dioxide (chemical
raction between the acid in the cartridge and the basic solution of the
charge) |
Opening of the valve.
Generation of carbon dioxide (chemical raction between the acid solution in
the cartridge and the basic solution of the charge) |
Opening of the valve. Action of pressurized gas
(opening of the cartridge) |
Opening of the valve. Action of pressurized gas (opening of the
cartridge) |
Opening of the valve
of the container consitituting the extinguisher |
Opening of the valve of the container consitituting
the extinguisher |
The
discharged extinguishing medium consists of:
|
Water, with possible salts in
solution |
Water with salts in
solution |
Foam containing carbon
dioxide |
Foam containing the gas
used |
Dry chemical powders and
carbon dioxide or other gas |
Carbon dioxide |
Halogenated
hydrocarbons |
The
discharged extinguishing medium causes the extinction of fire by: |
Cooling of the burning materials. Water
evaporation and consequent formation of a local atmosphere (water/steam)
which isolates the burning products from the surrounding air |
Formtion of a foam layer which isolates
the burning products from the surrounding air |
Inhibition of the combustion proecss by
interrupting the chemical reaction. Some separation of burning materials
from surrounding air. |
Formation
of a local inert atmosphere (carbon dioxide) which isolates the burning
materials from the surrounding air. Smothering and cooling action of carbon
dioxide. |
Inhibition of the
combustion proecss by interrupting the chemical
reaction. |