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FIRE PROTECTION SYSTEM

Prepared ByManoj Paudel

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Nepal’s Context

• On average, fires are responsible for property losses worth 350 million rupees and the deaths of 43 people annually. The average years sees more than 1500 outbreaks (MoHA, 2009).

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Thamel fire guts property worth Rs 200m

Fire started in the kitchen of Faces Lounge restaurant near the Kathmandu Guest House in Mandala Street .

- The Kathmandu Post (Posted on: 2013-05-18 09:49)

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What is Fire ?

A process in which substances combine chemically with oxygen from the air and typically give out bright light, heat, and smoke

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Fire Triangle

Fuel : Thing that burns

Heat: That causes fuel to burn

Oxygen: gas found in air

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Fire Tetrahedron

Once a fire has started, the resulting exothermic chain reaction sustains the fire and allows it to continue until or unless at least one of the elements of the fire is blocked

-fuel

-Ignition

-oxygen

-combustion

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Stages of Fire• Ignition: Fuel, oxygen and heat join together in a sustained

chemical reaction. At this stage, a fire extinguisher can control the fire.

• Growth: Convection and radiation ignite more surfaces. The size of the fire increases and the plume reaches the ceiling. Hot gases collecting at the ceiling transfer heat, allowing all fuels in a room to come closer to their ignition temperature at the same time.

• Fully developed: Fire has spread over much if not all the available fuel; temperatures reach their peak, resulting in heat damage. Oxygen is consumed rapidly.

• Decay (Burnout): The fire consumes available fuel, temperatures decrease, fire gets less intense.

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• Fire hazard is a situation in which there is a risk of harm to people or property due to fire

• Fire hazard can take the form of various ways that fires can start such as :blocked cooling vent or overloaded electrical system.Firing at insufficient protected fuel store or the areas with

high oxygen concentration .Firing of materials that produce toxic fumes when blocked

from escaping .

Fire Hazard

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CAUSES OF FIRE HAZARD

House Keeping Hazards

Friction Hazards Storage Hazards

Smoking Hazards

Electrical Hazards

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Fire Classes

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Fire Classes

• Class A: Ordinary combustible materials, such as wood, cloth, paper, rubber and many plastics. They burn with an ember and leave an ash. Extinguish by cooling the fuel to a temperature that is below the ignition temp. Water and other extinguishing agents are effective.

• Class B: Flammable liquids (burn at room temperature) and combustible liquids (require heat to ignite). Petroleum greases, tars, oils, oil-based paints, solvents, lacquers, alcohols, and flammable gases. High fire hazard; water may not extinguish. Extinguish by creating a barrier between the fuel and the oxygen, such as layer of foam.

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• Class C: Fuels that would be A or B except that they involve energized electrical equipment. Special techniques and agents required to extinguish, most commonly carbon dioxide or dry chemical agents. Use of water is very dangerous because water conducts electricity.

• Class D: Combustible metals, such as magnesium, titanium, zirconium, sodium, lithium and potassium. Most cars contain numerous such metals. Because of extremely high flame temperatures, water can break down into hydrogen and oxygen, enhancing burning or exploding. Extinguish with special powders based on sodium chloride or other salts; also clean dry sand.

• Class K: Fires in cooking appliances that involve combustible cooking media (vegetable or animal oils and fats).

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Putting out a Fire

Four ways to put out a fire

• Cool the burning material

• Exclude oxygen

• Remove the fuel

• Break the chemical reaction

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Fire Extinguishers

Portable or Fixed Installations type• Water : A 9 l water extinguisher is installed for each 210

sq.m floor area, with a minimum of two extinguishers per floor.

• Dry Powder: Dry powder extinguishers contain from 1 to 11 kg of treated bicarbonate of soda powder pressurized with CO2, nitrogen or dried air. Interrupts chemical reaction.

• Foam: contain foaming chemicals that react upon mixing or aCO2 pressure-driven foam. They cool the combustion, exclude oxygen

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• Vaporizing Liquid : Vaporizing liquid extinguishers use bromochlorodifluoromethane (BCF) or bromotrifluoromethane (BTM). More powerful than CO2 extinguishers

• Carbon Dioxide: Pressurized CO2 extinguishers leave no deposit and are used on small fires involving solids, liquids or electricity.

(Reference- Chapter 15, Building Services Engineering (5th Edidion) by David V. Chadderton )

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Using Portable Fire Extinguisher

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Which to Use ?Group Extinguishing

AgentFire Class Action

1 Water A Cools2 Dry Powder All Flame

Interference3 Foam B Excludes

Oxygen4 Carbon Dioxide B, C Excludes

Oxygen5 Vaporizing Liquid Small fires,

motor vehicles, C

Flame Interference

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Codes for Fire Safety

• Nepal National Building Code NBC 107:1994(Provisional Recommendation on Fire Safety)

• Nepal National Building Code NBC 206:2003(Architectural Design Requirements)

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• Exit from Building – Exit Doors, Staircase,

• Access to Building – enough space for entrance of fire fighters (people and device), space for parking of

• Visual Aids and Alarms• Lightning Arresters• Friendly escape route for

people with disability