Fire Science
"Tol! BFP ang target? Dapat alam mo ang science ng apoy. Hindi 'yan magic - may physics, chemistry, at thermodynamics yan! Master mo ito para maintindihan kung paano mag-behave ang apoy at paano talunin!"
1. The Fire Triangle vs Fire Tetrahedron 🔥
Dati Fire Triangle lang ang tinuturo. Pero ngayon, Fire Tetrahedron na! Bakit? Kasi nadiscover na hindi lang 3 elements ang kailangan - may isa pang kritikal na factor!
🔺 Fire Triangle (Old Model)
- 1. Fuel (Combustible Material):
- Solid: Kahoy, papel, tela, plastic
- Liquid: Gasoline, alcohol, kerosene
- Gas: LPG, natural gas, propane
- 2. Heat (Energy Source):
- Ignition temperature must be reached
- Sources: Matches, spark, friction, sun
- 3. Oxygen (Oxidizing Agent):
- Normal air = 21% oxygen
- Minimum 16% to sustain fire
- Below 16% = fire extinguishes
🔷 Fire Tetrahedron (Modern Model)
All 3 triangle elements PLUS:
- Free radicals sustain combustion
- Self-perpetuating process
- Basis for dry chemical extinguishers
- Break the chain = extinguish fire
Halon at dry chemical extinguishers attack this 4th element!
💡 Exam Tip: Pag tinanong kung ano ang difference - Chemical Chain Reaction ang sagot! This is why some fires are harder to extinguish kahit nawala na ang isang element.
2. Methods of Heat Transfer 🌡️
Ang apoy ay kumakalat through 3 methods. Mahalaga ito para maintindihan ang fire behavior at spread pattern!
🔥 Conduction (Direct Contact)
Heat transfers through direct physical contact of molecules.
- Example: Metal bar sa apoy - ang dulo mainit na rin
- Fire Spread: Through walls, metal beams, pipes
- Speed: Slowest method of heat transfer
- Factors: Material conductivity (metal > wood > air)
💨 Convection (Through Fluids/Air)
Heat transfers through movement of heated air or liquid.
- Example: Hot air rises, cold air sinks (circulation)
- Fire Spread: Upward and outward through ventilation
- Speed: Faster than conduction
- Danger: Fire travels up stairwells, elevator shafts, ducts
⚠️ Kaya pag sunog, NEVER use elevator! Fire spreads through convection sa shafts!
☀️ Radiation (Electromagnetic Waves)
Heat transfers through invisible electromagnetic waves. No medium needed!
- Example: Mainit ka kahit malayo sa bonfire
- Fire Spread: Can ignite nearby objects without contact
- Speed: Travels at speed of light
- Protection: Reflective materials, distance, barriers
⚠️ Large fires can ignite buildings across the street through radiation!
3. Phases of Fire Development 📈
Ang fire ay may predictable stages. Knowing these helps firefighters assess at respond properly.
Initial combustion. Smoke begins. Temp rising. Still controllable with extinguisher.
Fire spreads rapidly. Oxygen abundant. Temperature increases significantly.
All combustibles ignite simultaneously. Temp ~1000°F (538°C). Unsurvivable!
Maximum heat release. All fuel burning. Most intense period.
Fuel depleted. Fire diminishes. DANGER: Backdraft possible if oxygen introduced!
4. Dangerous Fire Phenomena ⚠️
Mga sitwasyon na dapat mong alamin - ito ang pumapatay sa firefighters!
🔥 FLASHOVER
- Transition from growth to fully developed
- All contents ignite simultaneously
- Temperature: 1000-1200°F
- Warning: Rollover/flameover at ceiling
- Survival: 0% after flashover
💥 BACKDRAFT
- Explosion when oxygen introduced
- Occurs in oxygen-depleted fire
- Signs: Smoke-stained windows, puffing smoke
- Hot door, inward air movement
- Prevention: Ventilate from highest point
🌀 ROLLOVER/FLAMEOVER
- Flames roll across ceiling
- Unburned gases ignite at ceiling level
- Warning sign of impending flashover
- Action: Get low, prepare to evacuate
💨 SMOKE EXPLOSION
- Ignition of accumulated smoke/gases
- Can occur away from main fire
- Similar mechanism to backdraft
- Prevention: Proper ventilation tactics
5. Products of Combustion 💨
Ang sunog ay nagpo-produce ng deadly byproducts. Maraming namatay dahil dito, hindi sa mismong apoy!
Toxic Gases:
- Carbon Monoxide (CO): Silent killer, colorless, odorless
- Carbon Dioxide (CO2): Suffocating, displaces oxygen
- Hydrogen Cyanide (HCN): From burning plastics, wool
- Hydrogen Chloride (HCl): From burning PVC
Other Products:
- Smoke: Particles that reduce visibility
- Heat: Can cause burns, dehydration
- Light: Flame visibility (useful for detection)
- Soot: Carbon particles
⚠️ 80% ng fire deaths ay dahil sa smoke inhalation, hindi burns!
6. Practice Questions 📝
1. What is the main difference between Fire Triangle and Fire Tetrahedron?
View Answer
The Fire Tetrahedron adds the 4th element: Chemical Chain Reaction. This explains why some fires continue even when one element is seemingly removed.
2. Which method of heat transfer is responsible for fire spreading up stairwells and elevator shafts?
View Answer
Convection - hot air rises and travels through vertical openings like stairwells, elevator shafts, and ventilation ducts.
3. What are the warning signs of an impending backdraft?
View Answer
Smoke-stained windows, puffing or breathing smoke, extremely hot door, inward air movement at openings, and yellowish-brown smoke.
4. What is the minimum oxygen percentage needed to sustain fire?
View Answer
16% oxygen is the minimum. Normal air has 21% oxygen. Below 16%, fire will extinguish due to insufficient oxidizer.
5. What is the leading cause of death in fires?
View Answer
Smoke inhalation (not burns) causes approximately 80% of fire deaths. Carbon monoxide (CO) is particularly dangerous as it's colorless and odorless.
💡 Exam Strategy Tips
- Fire Triangle vs Tetrahedron: Always remember - 4th element is Chemical Chain Reaction
- Heat Transfer: Conduction (contact), Convection (air/fluid), Radiation (waves)
- Backdraft vs Flashover: Backdraft = oxygen rush, Flashover = everything ignites
- Fire Phases: Memorize sequence - Incipient → Growth → Flashover → Fully Developed → Decay
- Toxic Gases: CO is #1 killer - colorless, odorless!
Test Your Knowledge! 🧠
Ready ka na ba? Take the practice quiz for Fire Science to reinforce what you just learned.
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