Incident Date:1/11/2012 Time:07:30 AM Fatality: 25 injuries: 131Total losses: <200 MM SR

Reading in Riyadh Liquefied Gas Explosion

This Presentation contains unsuitable Pictures

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Introduction

• In last 2 days we have gathered information about Riyadh biggest fire incident in history to correct some information which misguided professional in what happened at that morning.

• We have analyzed a lot of reports and Pictures to come out to a conclusion of what happened.

• The truck contains more than 17 tons of liquefied propane at 150 PSI pressure.

• In fire Since what happened is a vapor cloud at which called { UVCE}

• UVCE Stands for “ Unconfined vapor cloud explosion.

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• Location were the liquefied gas truck hit the causeway Post when trying to make a left turn at high Speed

Wind Directions

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ALZAHED Contractors Building

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Vapor Cloud Dimensions

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• Source of ignition from AlZahed Contractors building, and as we See the Amount of Damage is High in this Zoon

• Another avoidance of source of ignition is the high number of fatalities and injuries from AlZahed

Employees.

What Happens to a Vapor Cloud?

• Cloud will spread from too rich, through flammable range to too lean.

• Edges start to burn through deflagration (steady state combustion).

• A vapor cloud is defined as flammable and/or toxic materials heated above their boiling point and released to the atmosphere

• Vapor clouds may be visible or invisible on the material released to the ambient temperature, wind velocity, and humidity.

• Cloud will disperse through natural convection.

• Vapor cloud may ignite and flash, resulting in an explosion and flash fire. Anyone caught in the vapor cloud will likely be seriously injured or killed. Substantial material damage is also possible

• Vapor clouds may be toxic, flammable, or dependent both. Materials with boiling point below 21 C are assumed to vaporize 100%

• Flame velocity will increase with containment and turbulence.

• If velocity is high enough cloud will detonate.

Chemical Reactions

EXPLOSION = Rapid Equilibration of High Pressure Gas via Shock Wave

Physical Explosions Chemical Explosions

Propagating ReactionsUniform Reactions

Thermal Explosions Deflagrations(Normal Transport)

Detonations(Shock Wave)

Potential Energy Coursed by the explosion

PRESSURE, psig TNT EQUIV., lbs. per ft3

10100150

100010000

0.0010.020.031.426.53

TNT equivalent = 5 x 105 calories/lbm

Stored Volumes of Ideal Gas at 20° C

Impact of VCEs on People

70160290

470670

NA

12 5

10 1520 30 35

150

PeakOverpressure

psi

EquivalentWind Velocity

mph

Knock personnel down

Rupture eardrums

Damage lungsThreshold fatalities

100% fatalities

Effects

The area effected by 17 tons of LPG

125

10172050

100200500

1000

INVENTORY(tons)

1201502002502943104205306709001150

UVCE

Distancein Meters

Some views from the incident

Some views from the incident

Some views from the incident