Hazards from Process Infrastructure Systems

Douglas J Ferguson, PE – Consultant - DuET Process Safety & Fire Protection

Mary Kay O’Connor Process Safety Center -2007 International Symposium October 23-24, 2007

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What If What If ……??Process Infrastructure Systems

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Douglas Ferguson, PEDuPont Engineering TechnologyConsultant - Process Safety and Risk Analysis

Education: BSME - University of Texas – 1967PE License: 2004

Experience: 39 years DuPont experience, 17 years in PSM & Process Hazards Analysis. 6 years teaching - 5-Day PHA Leader Training course

Process Infrastructure Systems

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Process Infrastructure Systems

• PROCESS vs. INFRASTRUCTURE FACILITIES HAZARDS

• DEGREE OF ANALYSIS

• LOWER RISK, AND ACCEPTED AS “COMMON OR NORMAL” HAZARDS

• SAFETY BENEFIT FOR SERVICE FACILITIES USING IN-DEPTH CONSEQUENCE ANALYSIS

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Process Infrastructure Systems

COMMON OPERATIONS

• LPG Systems• Cryogenic Systems (N2, Argon, CO2)• Steam Generation (Boilers)• Compressed Gas Systems• Natural Gas (High / Low Pressure)

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Process Infrastructure SystemsPOTENTIAL HAZARDOUS INCIDENTS

• BLEVE/ Fireball• Vapor Cloud Explosion• Confined Space Explosion• Flash Fires/ Jet Fires• Asphyxiation• Cryogenic Temperatures• Overpressure/ Vessel Rupture

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Process Infrastructure Systems

POTENTIAL AREAS OF IMPACT

• Facility Siting Concerns

• “Knock-On” Effects on ProcessFacilities

• “Knock-On” Effects on Other ServiceFacilities

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Process Infrastructure Systems

LPG SYSTEMS

• Fire and flash fire

• Flammable vapor cloud- Unconfined- Confined/ Congested Areas

• BLEVE/ Fireball

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Process Infrastructure SystemsLPG SYSTEMS - BLEVE

Propane BLEVE Data

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50

100

150

200

250

10 psi 5 psi 2 psi

Overpressure, psi

Dis

tanc

e, F

t

500 Gal

1000 Gal

2000 Gal

4000 Gal

6000 Gal

8000 Gal

10000 Gal

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Process Infrastructure SystemsLPG SYSTEMS – BLEVE Fireball

Propane Fireball - 12 Kw/m2

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400

500

600

700

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900

1000

500 1000 2000 4000 6000 8000 10000

Propane Tank Volume

Dis

tanc

e, F

t

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Process Infrastructure SystemsLPG SYSTEMS – Vapor Cloud

• Dispersion for various size leaks

• Model to ½ LFL• Determine if cloud reaches confined

or congested areas• Model area to determine explosion

overpressure/ impulse• No confinement – flash fire/ thermal

burns

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Process Infrastructure SystemsLPG SYSTEMS – Vapor Cloud

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Process Infrastructure SystemsLPG SYSTEMS – Vapor Cloud

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Process Infrastructure SystemsLPG – Falk Plant Milwaukee 12/6/2006 – 3 killed, 46 injured - http://www.jsonline.com/story/index.aspx?id=538906

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Process Infrastructure Systems

CRYOGENIC SYSTEMS

• Asphyxiation concerns- Tank failures/ large leaks- Leak into confined space

• Cryogenic burns to exposed skin

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Process Infrastructure SystemsCRYOGENIC SYSTEMS

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Process Infrastructure Systems

BOILERS – Steam Generation

• Fuel supply leaks – natural gasor propane

- Flash fires- Confined/ congested space

explosion• Fire chamber – fuel rich explosion• Steam drum (water side) BLEVE

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Process Infrastructure Systems

COMPRESSED GAS SYSTEMS

• Primarily vessel overpressure concerns- Compressor overpressure- Relief failure- Tank degradation

• Impact on personnel adjacent equipment- Shrapnel- Overpressures

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Process Infrastructure SystemsCOMPRESSED GAS SYSTEMS

2 .0 - D a ta E n try - T a rg e t In fo rm a t io n

T a rg e t D e sc r ip tio n

D ista n c e F ro m B la st

C e n te rD ista n c e

U n i ts

D ista n c e to 1 0 p si 3 4 .5

D ista n c e to 5 .0 p si 5 0 .7

D ista n c e to 2 .5 p si 7 7 .7

D ista n c e to 1 .5 p si 1 0 8 .9

D ista n c e to 1 .0 p si 1 4 5 .0

f t

C le a r

B a c k

H e lp

N e x t

1000 FT3 – 150 PSI Vessel

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Process Infrastructure Systems

HI/ LO PRESSURE NATURAL GAS

• Flammable gas cloud• High pressure (& may not be odorized)• Flash fire• Confined/ congested Areas (especially

low pressure gas)• Radiation

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Process Infrastructure SystemsNATURAL GAS SYSTEMS

20” Diam. – 850 psig

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Process Infrastructure SystemsNATURAL GAS SYSTEMS 1.5” Diam. – 55 psig – Low wind speed

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Process Infrastructure SystemsNATURAL GAS SYSTEMS 1.5” Diam. – 55 psig – high wind speed

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Process Infrastructure SystemsNATURAL GAS SYSTEMS

Natural gas leak inside building

Outputs

Expanded Volume of Burned Gasses (VE) = 61033 cu ft

Volume of Cloud Before Combustion (Vc) = 683.31 cu ft

Volume of Vapor in Flammable Cloud = 64.91 cu ft

Minimum Release to Create Damage = 2.666 lbs

H = 15 ft.

W = 50 ft.

L = 75 ft. Vb = 56250 cu ft

Enter building dimensions on this form.

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Process Infrastructure SystemsISP CONCEPTS

• Minimum Inventories• Storage/ Operation at Lowest Possible

Pressures• Vessel Design for Largest Credible

Overpressures • Locate to Minimize Facility Siting and

“Knock On” Effects • Piping - Minimize Flanges/ Welded

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Process Infrastructure SystemsSUMMARY

• Lower Risk, accepted as “common or normal” hazards

• Quantitative Consequence Analysis• Facility Siting Considerations• Apply ISP Principles and Concepts• Safer and More Robust Service Facilities