52(consequence analysis)

Input Screen input cell

DOWN WIND CONCENTRATION CALCULATIONS

Release Rate 4.183 kg/sec

Elevation of Release 33 m

Wind Speed 4.5 m / sec

atmosphere condition night "day" or "night"

Molecular Weight 166 gm/mole

VESSEL PHYSICAL EXPLOSION

Volume of Vapour Space in Vessel 4 m3

Burst Pressure 1.50E+06 Pa

Cp/Cv for gas 1.4

FIRE AND EXPLOSION CONSEQUENCES

Fuel Involved: cyclohexane

Quantity of Fuel: 1000 lb

Heat of Combustion for cyclohexane : 20000 BTU/lb

Caution This Spreasheet should not be used for purposes other than CHEE 470

without a complete review of the calculation methods and tables

Down Wind Concentrations for Toxic Release or Flammability

Calculations per "Chemical Engineering Aug 1998"

Instructions: 1. Go to "input" sheet and enter release information

2. In this sheet under the yellow "concentration" column enter desired concentrations for analysis

3. Read Downwind distance fromthis sheet

Release Rate 4.183 kg / s from Input Sheet

Velocity 4.5 m / s from Input Sheet

Molecular Weight 166 gm/mole from Input Sheet

Density Air 1205 gm/cu m from Input Sheet

Atmospheric Stability night night or day from Input Sheet

Release Elevation 33 m from Input Sheet

Release Type Continuous

Material Buoyancy neutral

Ground Type Urban

Comment Concentration Calculated Downwind Distance

ppm vol mg / m3 ug/m^3 m miles

100 690 6.90E+05 208 0.13

EPRG 3 60 414 4.14E+05 269 0.17

EPRG 2 5 34 3.45E+04 1,125 0.70

3 21 2.07E+04 1,633 1.01

Odour Threshold 0.05 0 3.45E+02 32,442 20.16

0.25 2 1.72E+03 10,020 6.23

Calculation of Energy Release from a Bursting Vessel

(Does not include the effects of the gas or liquid burning/exploding)

Volume of Vapour Space in Vessel 4 m3

Burst Pressure 1500000 Pa

Cp/Cv for gas 1.4

Atmospheric Pressure 1.01E+05 Pa

Energy = 8,054,580 Joules

Note: 40 to 80% of the energy calculated above is usually converted to Blast Wave Pressure

Conversion Efficiency 80%

Energy from Blast = 6,443,664 Joules

Energy from Blast 6,107 BTU

TNT energy 1120 cal/gm

2016 BTU/lb

Explosion TNT equivalent 3.0 lb of TNT

Damage Caused by The Explosion Distance From Centre of Explosion (ft)

Large glass windows which are already under strain are broken 990

Loud Noise. Sonic boom glass failure 743

Typical pressure for glass failure 217

95% probability of no serious damage 120

large and small windows very likely to shatter 80

large and small windows are l00% shattered 312

Minor damage to house structures 62

Partial demolition of houses, made uninhabitable 47 1 psi overpressure

Steel frame of clad building slightly distorted 39

Non-reinforced concrete or cinder walls start to shatter 29

Non-reinforced concrete or cinder walls completely shattered 22

Lower limit of serious structural damage 27

Steel frame building distorted and pulled from foundations 22

Rupture of oil storage tanks begins 22

Rupture of oil storage tanks is complete 19

Wooden Utility poles snapped 16

Nearly complete destruction of houses (lower range) 16

Nearly complete destruction of houses (upper range) 13

Loaded trainwagons overturned 13

Loaded train boxcars completely demolished 12

Probable total destruction of buildings 11

Limit of crater lip 3

Lethality (low) 4

Lethality (high) 3

lung damage (low) 6

lung damage (high) 6

ear drum rupture 16

Overpressure at any distance

Choose Distance: 500

Overpressure at this Distance: 0.059

Note: 40 to 80% of the energy calculated above is usually converted to Blast Wave Pressure

Distance From Centre of Explosion (ft)

1 psi overpressure

Fireball Estimate Size and Damage/Injuries

Use this sheet to estimate the potential injury from a fireball

These Calculations are relevant to a fireball which has not reached detonation



ref: - "Industrial Explosion Prevention and Protection"; Frank T. Bodurtha

- "Loss Prevention In The Process Industries"; Lees; Vol 2

Fire Ball Size

mass of fuel = 454 kg

fireball dia = 45 meters

Duration of the Fireball

duration = 3.5 sec

Rate Material is Burned

Rate = 131 kg/sec

Heat Release Rate

Heat of Combustion = 20000 BTU/lb

Heat Release Rate = 3.47E+08 BTU/hr

Intensity of Thermal Radiation at any point from the fireball centre

distance from fireball centre = 100 ft

Intensity = 2762 BTU/hr sq ft

Fraction of Heat Release

Fr = 0.3

Thermal Radiation Effects Per tables 16.83, 16.79 ; Lees

Calculated Distance Calculated Distance Dose Dose

Along Ground From Fireball Centre

ft ft kJ / m2 BTU / sq ft

7 7 838 73.8

21 21 580 51.1

"Loss Prevention in Process Industries" pg 16/184, in the case of BLEVE when more than 35% of the liquid involved in the fire flashes, virtually all

the liquid released burns as a fireball.

31 79 125 11.0

105 128 1.6 0.1

26 26 37.5 3.3

30 30 30 2.6

37 37 19 1.7

42 42 15 1.3

These Calculations are relevant to a fireball which has not reached detonation


(carried from Input Sheet)

Dia=5.8(mass kg)^(1/3)

Eqt 16.15.10 ; Lees

from Input sheet

Eqt 16.15.18; Lees

Based on API RP 521

Duration Result Notes

sec

1.43 mortality of 99% of people

10 mortality of 50% of people ref: Lees table 16.79

"Loss Prevention in Process Industries" pg 16/184, in the case of BLEVE when more than 35% of the liquid involved in the fire flashes, virtually all

the liquid released burns as a fireball.

30 1st degree burns First degree burns are the onset of blisters

1 Continuous Exposure to People Okay

1 Damage caused to process equipment

1 spontaneous ignition of wood

1 cable insulation degrades

1 Ignition of wood

First degree burns are the onset of blisters

BLAST DAMAGE DUE TO OVERPRESSURE BY VAPOUR CLOUD EXPLOSION

Use this sheet in the case of an vapour cloud explosion

which has undergone a detonation



Explosion Efficiency 2%

TNT energy 1120 cal/gm

2016 BTU/lb

Explosion TNT equivalent 198.4 lb of TNT

Damage Caused by The Explosion Distance From Centre of Explosion (ft)

Large glass windows which are already under strain are broken 3989

Loud Noise. Sonic boom glass failure 2995

Typical pressure for glass failure 874

95% probability of no serious damage 485

large and small windows very likely to shatter 322

large and small windows are l00% shattered 1256

Minor damage to house structures 248

Partial demolition of houses, made uninhabitable 191 1 psi overpressure

Steel frame of clad building slightly distorted 158

Non-reinforced concrete or cinder walls start to shatter 118

Non-reinforced concrete or cinder walls completely shattered 90

Lower limit of serious structural damage 107

Steel frame building distorted and pulled from foundations 90

Rupture of oil storage tanks begins 90

Rupture of oil storage tanks is complete 75

Wooden Utility poles snapped 66

Nearly complete destruction of houses (lower range) 66

Nearly complete destruction of houses (upper range) 54

Loaded trainwagons overturned 54

Loaded train boxcars completely demolished 47

Probable total destruction of buildings 44

Limit of crater lip 11

Lethality (low) 16

Lethality (high) 13

lung damage (low) 26

lung damage (high) 23

ear drum rupture 66

Overpressure at any distance

Choose Distance: 500 ft

Overpressure at this Distance: 0.268 psi

THIS SHEET IS FOR INTERNAL CALCULATIONS

Scaled Distance ft / lb ^ (1/3) Overpressure (psi)

ln (distance) ln(psi)

3 1.098612289 70.5 4.255613

4 1.386294361 38 3.637586

5 1.609437912 25 3.218876

10 2.302585093 6 1.791759

20 2.995732274 2 0.693147

33 3.496507561 1 0

81 4.394449155 0.3 -1.20397

200 5.298317367 0.105 -2.25379

300 5.703782475 0.075 -2.59027

650 6.476972363 0.031 -3.47377

=EXP(0.011*LN(D5)^2-2.0765*LN(D5)+6.5166)

=EXP(0.077789*LN(D10)^2-1.929189*LN(D10)+5.78107)

y = 0.0402x2 - R =

0

1

2

3

4

5

6

7

-5 0 5

Overpressure (psi)

Overpressure (psi)

Poly. (Overpressure(psi))

100

Shock Wave Parameters

0.01

0.1

1

10

100

1 10 100 Overp

ressu

re (

psi)

Scaled Distance ft/lb^1/3

Shock Wave Parameters

y = 0.1313x2 - 2.41x + 6.7238

calc psi % error calc distance% err

66.87397 4.20281 -5.14331 3.083782 -2.79274

37.54225 3.625467 -1.20461 3.969897 0.752572

24.3145 3.191073 -2.74201 4.793759 4.124822

6.797391 1.916539 13.28986 10.13445 -1.34453

2.128037 0.7552 6.401831 20.16179 -0.80896

0.986692 -0.0134 -1.33079 32.71063 0.876889

0.288339 -1.24362 -3.88695 83.10095 -2.59377

0.101255 -2.29011 -3.5663 206.0574 -3.02869

0.067406 -2.69701 -10.1248 280.8878 6.370741

0.034541 -3.3656 11.42376 661.6599 -1.79382

=EXP(0.011*LN(D5)^2-2.0765*LN(D5)+6.5166)

=EXP(0.077789*LN(D10)^2-1.929189*LN(D10)+5.78107)

0.0402x2 - 0.726x + 3.4877R = 0.9997

Overpressure (psi)

Poly. (Overpressure(psi))

1000Scaled Distance ft/lb^1/3

THIS SHEET IS FOR INTERNAL CALCULATIONS

Vapour Vessel

Cloud Burst

Overpressure Scaled Distance Distance Distance

psi ft / lb^(1/3) ft ft

0.03 684 3989 990

0.04 513 2995 743

0.15 150 874 217

0.3 83 485 120

0.5 55 322 80

0.1 215 1256 312

0.7 43 248 62

1 33 191 47

1.3 27 158 39

2 20 118 29

3 15 90 22

2.3 18 107 27

3 15 90 22

3 15 90 22

4 13 75 19

5 11 66 16

5 11 66 16

7 9 54 13

7 9 54 13

9 8 47 12

10 8 44 11

300 2 11 3

690 100 3 16 4

1380 200 2 13 3

207 30 4 26 6

255 37 4 23 6

34 5 11 66 16

Damage

Large glass windows which are already under strain are broken

Loud Noise. Sonic boom glass failure

Typical pressure for glass failure

95% probability of no serious damage

large and small windows very likely to shatter

large and small windows are l00% shattered

Minor damage to house structures

Partial demolition of houses, made uninhabitable

Steel frame of clad building slightly distorted

Non-reinforced concrete or cinder walls start to shatter

Non-reinforced concrete or cinder walls completely shattered

Lower limit of serious structural damage

Steel frame building distorted and pulled from foundations

Rupture of oil storage tanks begins

Rupture of oil storage tanks is complete

Wooden Utility poles snapped

Nearly complete destruction of houses (lower range)

Nearly complete destruction of houses (upper range)

Loaded trainwagons overturned

Loaded train boxcars completely demolished

Probable total destruction of buildings

Limit of crater lip

Lethality (low) Bodurtha pg 66

Lethality (high)

lung damage (low)

lung damage (high)

ear drum rupture

52(consequence analysis)

Documents