4.3c flammable hazard v1.2 phillips depropanizer

7/28/2019 4.3c Flammable Hazard V1.2 Phillips Depropanizer

1/15


2/15


3/15


4/15


5/15

Event Tree Outcomes 6/27/2013

Large LPG Immediate Wind To Delayed Congested Ignited Jet

Leakage Ignition Pop'd Area Ignition Area Points @ Tank

A B C D E F

Yes

0.1

Yes BLEVE

0.9

0.9 Local Thermal

Hazard

No

Yes

0.1

VCE

Yes Yes

0.9 0.1 Flash Fir

& BLEVE

Yes 0.90.125

Large Leak No 0.9

1.00E-04 Flash Fire

No

0.1

Safe Dispersal

No

0.1

Yes

No 0.1

VCE

Yes

0.9 Yes

0.1 Flash Fir

& BLEVE


6/15


C Wind Blowing Toward Populated Area 0.125 Wind Rose data

D Delayed Ignition Near Populated Area 0.9 Expert Opinion

E Congested Area w Vertical Confinement0.1

Historical DataF Jet Flame Strikes Pressurized Vessel 0.1 Layout & Piping Geometry


7/15


Frequency

Per Year

9.00E-06

8.1E-05

1.1E-07

1.0E-07

9.1E-07

1.3E-07

7.9E-07

7.1E-07


8/15



9/15

Vessel Hazards and Consequence Analyses 6/27/2013

BLEVE FIREBALL HAZARD CHARACTERISTICS 27-Jun-13

1:11 AM

Vessel = Guidelines for Chemical Process Quantitative Risk Analysis

Case Phillips Explosion

Maximum Storage Quantity = 85,200 lbs Isobutane

Hemispherical Ground Fireball Diameter = 658 ft. 200.63

Fireball Duration for Complete Combustion, td = 13.28 secs

Calculated Fraction Radiated = 0.4000

Enter Probit Case No. (1 to 8) 4 For Eisenberg For Eisenberg Ground

Thermal Dose Thermal Dose Distance

(4) 2nd Deg Burns = LC01 Therm Flux Probit Value Pr Distance Pr Distance X

Exposure, t, In sec. kW/sq. m Pr ft. meters Meters1.0000 171.9874 2.6699 1,484 452.48 441.22

30.00 13.4170 2.6699 1,005 306.35

100.00 5.4387 2.6699 873 266.00

Probit Constants For BLEVE Fire Pr =A+B*LN(I^n*t) See Page 160, CPQRA

"A" FACTOR -14.9 By Eisenberg et al in 1975

"B" FACTOR 2.56 Consequences more conservative than by Mudan

"n" FACTOR 1.333333 Fireball Durn 13.28 sec

Therm Flux At Grnd Dist, X,

Fireball Hazard Incid Therm Fireball Probit Value Fireball Dur'n Fr Epicenter

kW/sq. meter Exposure, sec Pr kW/sq. meter ft.

(1) US Threshold Of Pain 9.5000 8.00 -1.8922 6.50 1,984

(2) UK Threshold Of Pain 6.3000 30.00 0.0895 11.61 1,524

(3) 1st Deg Burns 7.4696 30.00 0.6707 13.77 1,406

(4) 2nd Deg Burns = LC01 13.4170 30.00 2.6699 24.73 1,055

(5)10% Fatality 18.1750 30.00 3.7059 33.50 901

(6) 50% Fatality 26.5500 30.00 4.9995 48.93 732

(7) 90% Fatality 38.6400 30.00 6.2804 71.21 585

(8) 99.9% Fatality 65.4700 30.00 8.0802 120.66 404

Eisenberg Single Point Study, Tau By Roberts H L

X

Det Thermal Harard @ X = 1,055 ft. meters = 321.52 A solution example for

Max Fireball Duration, td = 13.28 secs (2) UK Threshold Of Pain

Exposure Time at 1054 ft. 13.28 seconds A Constant 2.7352E-06

Thermal Flux at 1054 ft. 24.73 kW/sq. meter B Constant 0.000311111

Probit Value At 1054 ft. = 2.6699 C Constant -0.765555556

See Consequence Range Below Solution To Quardratic


10/15

0.10

1.00

10.00

100 1,000

P

S

O

i

n

p

s

i

g

Distance From Vessel, Feet


11/15

10,000

Clancey

Gugan

Flix Pts.

Edge Of Cloud


12/15

0.1

1.0

10.0

100.0

1 10 100 1000

T

i

m

e

S

e

c

Incident Thermal Flux, kW/sq m

Fig 2.33: Serious Injury/Fatality Levels For Thermal Radiation (Mudan, 1984), CPQRA, p-161

Near 100% Fatal

Mean 50% Fatal

2nd Deg Burns

1st Deg Burns

Pain Threshold

Mudan LC50 Pt.

Single Pt. Case

Eisenberg LC50


13/15


14/15

Flowsheet


15/15

Scale = 0 200 400 ft.

4.3c flammable hazard v1.2 phillips depropanizer

Documents