Bundwan Polytechnic
Department of Electrical Engineering
Lab Manual by – Shri Palash Das
Lecture in Electrical Engineering
Experiment Name: Study of fire fighting extinguisher
Experiment Number:02
Aim:
1. To identify different types of fire fighting extinguisher
2. To apply appropriate fire fighting extinguisher according to the class of fire and situation.
Theory:
Different types of fire fighting extinguishers available. According to clash of fire the fire fighting extinguisher should be chosen. The effect of firefighting extinguisher truly depends on class of fire fighting extinguisher and the situation of the fire hazard. According to study of fire fighting extinguisher a least is given below
1. Hose Reels: These provide the best method of first aid firefighting for class A fires. They consist of 25.40 m length having diameter of 63 mm of reinforced rubber tubing connected to a pressurised water sup- ply with a shunt off nozzle attached to the end of the hose. It can extin- guish fire with a distance of 10 m.
2. Water filled extinguishers: It is most suitable type for use against fires involved solid materials, usually of an organic nature, in which com- bustion normally takes place with the formation of glowing embers. There are two methods of operation .e., stored pressure and gas cartridge type.
In stored pressure type water is expelled by stored pressure which is supplied from an air pump or cylinder and in cartridge type water is ex pelled by CO2 gas supplied by a replaceable cartridge fitted within the appliances The soda acid type is one of the early type of water extin- guishers. See Fig E-2.2
3. Carbon Dioxide (CO2) Type: Fire extinguishers filled with CO₂ are easily distinguished by the distinctively shaped discharged hom. CO extinguishers may be operated by means of a plunger lever trigger or by opening a valve. These are suitable for fires involving liquids liquifiable I solids See Fig. E-23
4. Halogen Extinguishers: These extinguishers may be filled with chloro-bromo ethane. Bromo-chloro difluromethane or Bromo trifluromethane. They may be either gas cartridge or stored pressure type .Halogen extinguishers are used mainly because of their effectiveness in rapidly extinguishing small fires involving burning liquids As the chemicals are electrically non-conductive to electrical equipment See Fig E- 2.4
5. Dry Powder Extinguishers: Extinguishers filled with dry powder may be of the gas cartridge or stored pressure type They are similar in appearance to their water filled counterparts and have the same method of operation. The main distinguishing feature is the fan shapped nozzle. See Fig. E-25
6.Foam Extinguishers: Foam extinguishers may be stored pressure or gas cartridge. They are most suitable for use on flammable liquid fires such as petrol, oil grease, and fats, where the risk of re-ignition is high and where the liquid is contained. They are not suitable for running liquid fires and must into be used on fires where electrical equipment is in- volved See Fig E-2.6
Extinguisher Trolley Unit:
Large size containers of the dry powder, foam and CO₂ types are often mounted on wheeled trolly and positioned at points from which they can be quickly wheeled to the scene of an outbreak These containers are equipped with a stop clock and suitable nozzle attached. These are generally lever operated. See Fig. E-2.7.
Specification:
Write down the specification according to your observation.
Write it in a separate page
Precautions
1. All water filled extinguishers must be protected against frost dam-
Age. 2. Always check the operating instruction on the container before
Use. 3. Always ventilate thoroughly after extinguishing a fire indoor.
Conclusion:
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