Rafineri Floating Roof Tank: NFPA 11 Rim Seal Foam ve Buncefield Dersi

Rafineride cok buyuk hampetrol/gasoline tanklari (50,000-150,000 m3) floating roof (yuzer tavan) ile havaya maruziyeti azaltir. Yildirim veya statik elektrik rim seal (tavan kenar sızdirmazligi) yanginlari baslatir. NFPA 11 rim seal foam, semi-subsurface foam ve full-surface foam yöntemlerini tanimlar. Buncefield 2005 (UK) ve Jaipur 2009 (India) buyuk kazalardir.

Tank Tipleri

• Floating roof (FRT): Yuzer tavan, sivi ustunde
• Internal FRT (IFRT): Dis sabit tavan + ic yuzer
• Fixed roof: Sabit - kucuk tanklarda
• Rim seal: Primary (shoe) + secondary (fin)
• Vapor tutum: Flotating az, fixed cok

Rim Seal Yangini

• Sebep: Yildirim (50-70 percent), statik, kaynak
• Alan: Rim genislik dar - 400 mm
• Cevre uzunlugu: 80 m capli tank = 251 m
• Foam debi: 12.2 L/min/m2 (0.3 gpm/sqft)
• Duration: 20 dk

NFPA 11 Foam Tipleri

• AFFF (aqueous film): Hızli kapanir, flashback zayif
• AR-AFFF (alcohol-resistant): Polar çözücü (metanol)
• FP (fluoroprotein): Uzun kaplanma, subsurface ideal
• F3 (fluorine-free): 2026 gecis - PFAS yasak
• High-expansion: LNG/amonyak icin

Full-Surface Yangin

80 m capli tank, full surface:

• Alan: A = π × 40² = 5027 m2
• Debi: 6.5 L/min/m2 → 32,670 L/min
• Sure: 65 dk (0.35 mobilizasyon dahil)
• Foam konsantre: 3 percent → 980 L/min x 65 = 63.7 m3
• Su: 32,670 × 65 = 2,124 m3

Buncefield 2005 Dersi

• Olay: Benzin tankı overfill, vapor cloud explosion
• Hasar: 2 Mt infilak buyukluk, 43 yarali
• Sebep: Tank seviye alet arizali
• Ders: Yuksek-seviye alarm bagimsiz, high-integrity
• Process Safety: API 2350 overfill prevention

FRT SprinkCalc ile

SprinkCalc rafineri floating roof tank rim seal foam, full-surface debi, subsurface injection ve NFPA 11 uyumluluk hesaplamalarini yapar.

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