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John Reinhardt FAA Fire Safety Section, AAR-422. “Minimum Performance Standard for Aircraft Cargo Compartment Fire Suppression Systems”. BULK LOAD FIRES. CONTAINERIZED FIRES. AEROSOL CAN EXPLOSION SIMULATION. FLAMMABLE LIQUIDS FIRE. BULK LOAD FIRE TEST.
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John Reinhardt FAA Fire Safety Section, AAR-422
“Minimum Performance Standard for Aircraft Cargo Compartment Fire Suppression Systems” BULK LOADFIRES CONTAINERIZED FIRES AEROSOL CAN EXPLOSION SIMULATION FLAMMABLE LIQUIDS FIRE
BULK LOAD FIRE TEST Fire Load = 178 card board boxes (30% of Vol.) containing 2.5 lbs of shredded paper Ignition = nichrome wire wrapped around folded paper towels System Activation = 1 min. after one of the ceiling T/C reaches 200 oF Test Duration = Five tests @ 30 minutes each
CONTAINERIZED FIRE TEST Fire Load = 33 card board boxes inside an LD3. Three LD3 in Compartment Ignition = nichrome wire wrapped around folded paper towels System Activation = 1 min. after one of the ceiling T/C reaches 200 oF Test Duration = Five tests @ 30 minutes each
SURFACE BURN FIRE TEST Fire Load = 0.5 U.S. Gallon of Jet A fuel (with 13 oz of gasoline) Ignition = Arc created by two spark plugs System Activation = 1 min. after one of the ceiling T/C reaches 200 oF Test Duration = 5 minutes
AEROSOL CAN EXPLOSION SIMULATION Fire Load = 58 card board boxes containing 2.5 lbs of shredded paper Ignition = nichrome wire wrapped around folded paper towels System Activation = 1 min. after one of the ceiling T/C reaches 200 oF Activate Simulator when one of the cans temp. reaches 400 oF (or test time = 29 minutes) Test Duration = Five tests @ 30 minutes each
Water Mist System • Water Mist System Combined • With Nitrogen
High Pressure/Class I Water Mist System • High Pressure Pump (1150 psig) • 125 Gallon Water Tank (Pressurized to 40 psig) • Solenoid Valves • Number of Nozzles = 32 • Nozzle Angle = 90o Down • Max Flow Rate per Nozzle = 0.10 gpm • Number of Zones = 4 • Nozzles per Zone = 8 • Droplet size = 70 to 100 microns • Distance Between Nozzles = 16” • Distance Between Zones = 30” • Activation Controller (Trigger Temperature - 212 oF) Environmental Engineering Concepts
ACTIVATION CONTROL LOGIC: • Two zones near fire will turn on for 5 minutes to knock down flames and cool down the cargo compartment. • After the 5 minutes: • - A zone will turn on only if the temperature near the zone exceeds 212 oF; turn off if temperature is below it. • - All zones will turn on if the ceiling temperature exceeds 350 oF.
- High Pressure/Class I Water Mist System (As described before) • - Nitrogen System consisted of: • 16 Cylinders Size-T Nitrogen Bank • Two Matheson Model 3020 Regulators • System Flow Rate = 37.5 CFM to 89.3 CFM • Pneumatic Valve • One inch plumbing network • 5 Nozzles (5/8” ID) • Activation was controlled by the volumetric concentration of Oxygen (10%) in the cargo compartment (Closed loop control system)
A class I, high pressure water mist system did not pass the MPS for aircraft cargo compartments due to its incapability to inert the compartment against a HC explosion. • The same water mist system combined with a nitrogen system passed the MPS with a competitive weight factor*. The weight advantage will come from using the proposed fuel tanks OBIGGS system for nitrogen generation.