PowerPoint Presentation · Presentation title •date 10M Upper and Lower Flammmable Limits LFL...
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22/09/2018 1 The Fire Risk Challenges Steve Emery University Officer Historic Buildings Prior Park House 1835 156 years later Prior Park College 1991 Triangle Of Fire Convection Conduction Radiation Direct Flame impingement Flashpoint Auto ignition Heat transfer and ignition
Transcript of PowerPoint Presentation · Presentation title •date 10M Upper and Lower Flammmable Limits LFL...
22/09/2018
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The Fire Risk Challenges
Steve Emery
University Officer
Historic
Buildings
Prior Park House 1835
156 years later Prior Park College 1991
TriangleOf
Fire
ConvectionConductionRadiation
Direct Flame impingementFlashpointAuto ignition
Heat transfer and ignition
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Presentation title • date
10M
Upper and Lower Flammmable Limits
LFL 1.4%
UFL 7.6%
Auto Ignition TemperaturesThe temperature when an item will automatically ignite in
air without the presence of a flame
• Petrol 400 C
• Pine 427 C
• Oak 482 C
• Propane 540C
• Pitch 500C
• Melting Point of Lead: 327.5 ° C
• Temperature of propane flame tip: 1995 ° C +
• Temperature of candle flame: 829 C
Does the thickness of the wood matter?
Does the orientation of the wood matter?
We do not know how many fires we have in heritage buildings !
There are no statistics, but we do know that ;
90% of all fires go out or are extinguished without the
fire service being called.
Electrics and cooking are major causes of all fires
46% of church fires are caused by arson
Control of contractors is imperative.
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Unventilated fire
• 1Kg of fuel needs 6 cubic metres of air
• Fuel in crib one = 42Kg
• 42Kg uses 252 cubic metres
• Size of room 5x10x5 = 250 cubic metres
5M Unventilated
34 Minutes
Heat Gradient
Pressure gradient
Visibility and
toxicity gradient
Rad
iati
on
Inte
nsi
ty
KW
/M2
Auto ignition of pine 427 degrees C
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27M x 13 M = 351 Sq M x 12 M = 4212 Cubic M
200 Chairs & 0.2 MW each = 40MW
40/351 = 0.1 Mw/sq M
Door GF 20
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