Fire Prevention & Protection Systems:
A broad classification of fire safety system is explained below
• Fire Safety ( Existence fire hazard & awakening of fire consciousness of the management)
• Fire Prevention
Detection by Detectors (alarms)
Elimination of hazard or source of ignition
Control over combustibles in storage, handling & process
• Fire Protection
Fire resistant design of buildings, equipment, means of escape & fixed installations
Suppression, Extinguishment or control by various extinguishers
• Fire fighting
Equipment & Hardware
Staff, training & readiness
Fire Safety ( Existence fire hazard & awakening of fire consciousness of the management)
- Concept of Fire, Fire Triangle, Fire Tetrahydran
- Methods of Fire Extinguishment
- Factors Contributing to Fire
- Classification of Fire
- Common causes of industrial fire
- Concept of fire load
FIRE IS CHEMICAL REACTION IN WHICH SUBSTANCE (FUEL) COMBINES WITH OXYGEN MAKING AN EXOTHERMIC REACTION WITH THE EMISSION OF LIGHT, HEAT & SMOKE.
Elements of Fire
• It takes three things to cause a fire:
–Heat - or something that is hot
–Fuel - or something that will burn
–Oxygen - the air that is all around us
METHOD OF FIRE EXTINGUISHMENT :
Cooling -Removal of heat. (Best cooling media is water)
Smothering -Reducing % of oxygen. Cutting off the supply of oxygen. (Blanketing, Use foam)
Starvation - Removal of fuel or removal of combustible material
FIRE CLASSIFICATION :
A - Solid Fuel
B - Liquid Fuel
C- Gases Fuel
D - Metal Fire
(Not Class) E - Electric / Electronic
K- Kerosine / Kitchen fire
CONCEPT OF FIRE LOAD:
• Fire load is the concentration or amount of combustible material in a building per sq.m. of floor area.
• It is defined as amount of heat released in kilo calories by the fuel per sq.m. area of the premises.
• It is useful to calculate the water requirement to quench the fire.
• 1cc of water absorbs 1 cal of heat when the temp is raised by 1 0C
Six fundamental principles of fire prevention & reduction :
1. Fire prevention Engineering
2. Regular periodic inspection
3. Prevent the start of fire
4. Early detection & extinguishment
5. Limiting the spread & damage due to fire & fire control
6. Prevention of personal injuries from fire or panic, including prompt & orderly evacuation of personnel.
Extinguishers are of two types:-
• Portable
• Fixed
PORTABLE FIRE EXTINGUISHERS:
WATER TYPE (IS 934,5506,940,6234)
FOAM TYPE (IS 933,5507,10474,10204)
DRY CHEMICAL POWDER (IS 2171,10658,11833)
CARBON-DI-OXIDE (IS 2878,8149)
HALON SUBSITUTE (IS 11108)
Fixed fire installations:-
1. Fire Hydrants-Hose reel, hose box, Fixed monitor, portable ground monitor, trolly mounted water monitor
2. Automatic water sprinkler
3. Water spray system
4. Foam system
5. CO2 system
6. DCP
7. Vaporising liquid system
8. Steam system
9. Inert gas system
10. Air agitation
11. Drenchers
Fire Detection & Alarm systems-Types are
1. Thermal expansion detector
2. Radiant energy detector
3. Light interference detectors
4. Ionization detector
Explosion
• Explosion is the result of rapid combustion with a sudden, violent change of pressure involving the liberation & expansion of a large volume of gas.
• The released energy may appear as heat, light, sound or mechanical shock.
• Its effect depends on the rate at which the energy is released.
Types of Explosion
1. Dust explosion
2. Deflagration
3. Detonation
4. Confined & Unconfined Vapour Cloud Explosion (VCE)
5. Boiling Liquid Expanding Vapour Explosion (BLEVE)
