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AUTOMATIC
CO2 SYSTEM
First
few application of manually operated CO2 system
were on the large cooking vats in the big restaurants in 1920's
and then in the newspaper printing room by 1925.
It
was noted in 1929 that the CO2 Fire Extinguishing
System was the best method to minimize damage of rotating
electric machinery from fire hazards and the application of
this system became the usual practice in USA and JAPAN. By
the end of 1893, a large number of rotating equipment particularly
Hydel generators were protected by CO2 system.
Among them were the 100,000 kva generators of the Shinho Power
Plant in Korea and the 75,000 kva generators installed at
the Sungari Power Plant in Manchuria. As a result of experience
and study many refinements and improvements were made and
many patents were taken out. The system of prolonged co2 discharged
which is today a standard requirement because of its economy
and reliability, was patented by a Japanese Co in 1950.
In
India, we find one of the first installation in new Cossipore
Generating Station of CESC for OCBs in 1953. First set of
Hydel Generators were protected in Maithon.
Manufacture
of fixed CO2 Fire Extinguishing Equipment started
around 1920's in USA and in 1928 the first set of standard
NFC 12 was being drafted by the Committee on manufacturing
risks and special hazards of NFPA. This was adopted IMMEDIATELY
by NBFU and later on in 1977 by ANSI.
Manufacture
started in India in 1970's and became a standard requirement
in BHEL hydel sets. IS:6382 was drafted well in advance and
was adopted in 1971 itself.
The
application of CO2 Fire Extinguishers is most advanced
in the United States of America. American practices are still
followed as such as possible and tot which are added special
features and improvements.
TWO
METHODS FOR SMOTHERING FIRE WITH CO2
As CO2
gas is stable and non-inflammable, a fire may be extinguished
by:
- Completely
surrounding the fire with CO2 gas
- Reducing
the oxygen content of the atmosphere around the fire by
the - introduction of CO2 to less than 15%
CHARACTERISTICS
OF CO2 AS A SMOTHERING AGENT IN COMPARISON WITH
OTHER INERT GASES AND SMOTHERING LIQUIDS
- Non
poisonous and odourless
- Plentiful
supply
- Excellent
power to overlay air because of its weight.
- Economical
in the cost of containers for instance, the container capacity
ratio of N2 and CO2 is 1 to 2.66.
- Non-corrosive
to metals, insulators and the burning material itself.
- Minimum
damage since the smothering action is speedy because of
its rapid discharge characteristic.
- Better
insulating power which is 1.2 times air.
- Advantage
of cooling and drying action when vapourizing from liquid
form.
- Smothering
action is absolutely complete in all inaccessible parts.
- Convenient
for automatic operation and remote control.
- Stability
will not change in characteristics even after long storage.
- Fully
efficient in any climate even at temperatures as low as
minus 56 deg. C.
ELEMENTS
OF A CO2 SYSTEM
- A
Carbon Dioxide Fire Suppression system consists of one or
more bank of cylinder storage containers to supply the CO2
extinguishing agent. Flexible discharge bends, or hoses,
connects the cylinders into a piping manifold. The manifold
in turn distributes the agent into the piping network. Nozzles
regulate the flow of CO2 into the protected area.
- Before
Carbon Dioxide is released into the protected facility,
fire must be detected by a detection and control system.
COMPONENTS
OF CO2 SYSTEM
 CO2
Cylinders- Nozzles
- Mechanical
Auto Discharge Components
- Evacuation
Signs
- Pilot
Cylinders
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