Transcript stanchekfire.ppt

Fires, Firefighting, and
Explosions
Fires
Firefighting Equipment
Firefighting
Indirect Firefighting
Explosions
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Fires
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The Fire Triangle
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Classification of Fire
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A
(ash)
Carbon-paper,wood,coal
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B
(boil)
Liquids-gasoline,diesel fuel
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C
(current) Electrical- cables, motors
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D
(ding)
Metals- magnesium, titanium
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Firefighting Equipment
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Hand Held Extinguishers
Rockdust
Water
Foam
Inert Gases
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Hand held
Extinguishers
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Monammonium phosphate
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Rated for ABC fires, interrupts the basic chemistry of fire.
Not recommended for D fires. (Red body & pressure gauge)
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CO2
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Rated for BC fires, will only extinguish surface area, heated core may reignite.
(Red body & horn, no gauge)
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Halon
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Rated for BC fires, used mainly in electronics, dangerous because Halon displaces
oxygen. (Red body and gauge)
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Pressurized Water
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Rated for A fires only, usually a baking soda charge. (Stainless steel body)
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Using hand held extinguishers
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Remember:
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Select the right type
Used mostly for small fires
Will usually discharge in less than one minute
Training is a must
Stay low to avoid fumes
Never block escape route
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When extinguishing a fire “PASS”
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P
A
S
S
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Pull the pin
Aim low
Squeeze the handle
Sweep from side to side
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Water
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Water is highly effective on Class A fires, by cooling down
the fire and surrounding atmosphere.
At most mines, water is usually in plentiful supply.
Can be used to cool down the firefighting team to prevent
heat exposure.
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Disadvantages
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Water should not be used to control a B or C fire.
Inadequate pressure or too high pressure
The volume of water can be restricted to the length of water
lines and hoses(frictional loss- 1/2 lbs. for every ten feet of
1 1/2 inch hose).
The fire nozzle can clog to non-filtered materials in the
lines.
Hydrogen can be produced by applying water to super hot
fires.
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Nozzles
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Many mines use fixed nozzles that limit
the amount of water to be used
Volume not pressure will put out the fire
Nozzles in the mine today may not handle
the high water pressure and may blow out
Hoselines
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Any hoseline under 2 inch diameter will
have frictional loss
Hoselines must a bursting pressure at
least 4 times the mine’s outlet pressure
Multiple walled hoses should only be used
Proper deployment and storage of
hoseline will determine if firefighting
efforts are successful
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Foam
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Protein
– Animal protein from entrails or blood (Class A & B fires)
– Burn back protection, not film forming, adheres well to roof
Fluoroprotein
– Animal protein with fluorinated surfactants (Class A & B fires)
– Burn back protection, film forming
Aqueous Film Forming Foam (AFFF)
– Synthetic (Class A & B fires)
– Burn back protection, film forming
Alcohol Type Concentrates (ATC)
– Used mainly in alcohol based liquids (Class A & B fires)
– Burn back protection, film forming
High Expansion Foam
– Special detergent concentrate, expands 1000 times its own volume
(Class A fires)
– No burn back protection, not film forming
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Training
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All persons directly involved should have hands on
training.
Support personal should participate in monthly mine
rescue training and MERD exercises.
Mine rescue team members shall have at least 4 hours
training monthly or 8 hours bimonthly(Pa State Trained
Teams train at least 6 hours monthly).
State Trained teams
participate in simulated
exercises at Niosh(Lake
Lynn facility and
Bruceton.
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Before Going Underground
All persons should be
aware if the fire is
spreading or a possible
explosion can occur.
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Before sending teams underground make sure that:
A. The main fan is running
B. A guard is monitoring the operation of the fan
C. Tests are being made at main returns for any mine
gases
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Do not make any sudden changes in mine
ventilation
Determine location of battery or diesel operated
equipment
Determine location of storage areas for
explosives, oil and grease, diesel fuel, bottled gas
Cut off electric power to affected area, to prevent
arcing starting additional fires and safety to mine
rescue teams.
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Locating Fires & Assessing Conditions
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Information given by mine officials and workers where
smoke, fumes or heat was last seen
The amount of afterdamp gases could determine what is
burning and how much is burning
Laboratory analysis could determine if the fire is still
burning
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Information received from the rescue
teams during exploration
 Gas readings near the fire area to
determine if the atmosphere is
potentially explosive
 Check on ventilation controls for
damage
 Roof must continually be evaluated
since heat will weaken the strata
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Direct Firefighting
Firefighting teams have to be very
close to the fire area
Teams should approach fire from
intake side to ensure safety
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High volume of water is recommended
Use of wide angle fog for team safety and
steady steam for direct contact with fire
Hazards include: electrocution, toxic and
asphyxiating gases, explosive gases, heat,
smoke and steam
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Use of a transverse brattice
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Indirect Firefighting
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Mine hazards include: high temperatures, bad roof, or
explosive gases
Necessary to fight the fire from a distance by sealing the
area or by filling the fire area with foam or water
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Six factors to consider sealing the fire
area:
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1. Volatility of the coal seam- High vol coal burns faster and
much more difficult to fight directly
2. Amount of methane liberated by the coal seam
3. Location of the fire and the area involved
4. Presence of head coal and the composition of roof strata
5. Availability of materials and transportation
6. Building sites for the seals
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Sealing the Area
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Purpose: to lower oxygen level so fire may burn out in
addition to foaming or flooding the area
Seal area should have good roof
Even roof and rib
Temporary seals should used before permanent seal are
built
Air sampling tubes install for gas and temperature readings
Make sure no abrupt ventilation change over fire area
All persons should leave mine in case explosive gases
build up in seal area
Possible to use boreholes from surface to pump water
and/or nitrogen to fire area
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Explosions
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As in fire, explosions need fuel, oxygen and heat
Methane and/or coal dust are the most likely source of fuel(
2% methane and the right amount of coal dust can create
an explosion)
Coal dust explosions travel at a speed exceeding 3000 ft.
per second
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Ignition sources include: electric arc, open flame, misuse
ox explosives, sparks from continuous cutting heads
Once an explosion occurs, there is a chance of more
explosions due to the ventilation systems being damaged
Before going under ground, make sure that the fan is
running and guarded
Tests are made at the fan for dangerous gases
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