CALCULATION SHEET Date

FLARE SIZING Rev.

CNG LAMPUNG Page
Input Data
Vapor flow rate, Qm lb/h 17017.66
kg/h 7709
Relative molecular mass, MW 24.79
Flowing Temperature, T R 497.83
Heat Combustion, Hc BTU/lb 18917.008
MJ/kg 44.05
Specific heat ratio, K (Cp/Cv) 1.234
Flowing pressure at flare tip, P psia 14.69
kPa 101.3
Wind Velocity, Uµ m/s 28
ft/s 91.87
Compressibility Factor, Z 0.991

Calculation for Flare Diameter

Mach No., Ma 0.2
Inside Diameter, d ft 0.630
in 7.560
m 0.192
Calculated Mach No. 0.2
Calculation of Flame Length
Heat Liberated, Q Btu/hr 3.22E+08
Length of flame, L Use figure 6 in API 521 ft 70.86
m 21.6123
Calculation of Flame Distortion caused by Wind Velocity
Vapour flow rate, qvap ft3/s 69.21
Flare Tip velocity, Uj ft/s 222.01
uµ/uj 0.41
Use figure 7 in API 521 0.20
Use figure 7 in API 521 0.95
ft 14.18
∑▒ 〖∆� / ft 67.32
�〗
∑▒ 〖∆� /
�〗
Calculation
∑▒∆� of Required Flare Stack Height
Fraction
∑▒∆� of Heat Radiated, F 0.3
Max. Allowable Radiation, K Use Table 12 in API 521 BTU/h.ft2
500
kW/m2 1.58
Fraction of the radiated heat transmitted through the atm, t 1
Distance from flame center to grade-level boundary, D ft 123.98
Radius Distance Max., r ft 131
Radius from flare center, r' ft 97.34
Flame heigth, h' ft 76.79
Flare Stack Height, h ft 69.70
m 21.26
Flame Center
Horizontal Distance of flame center from the top of flare stack, xc ft 33.66
m 10.26
Vertical Distance of flame center from the top of flare stack, yc ft 7.09
m 2.16
 Dimensional Reference for Sizing Flare Stack
∑▒∆�
67.32 ft

L 70.86 ft
Wind direction

91.87 ft
∑▒∆�
14.18 ft
yc
7.09 ft

xc
33.66 ft
d

0.63 ft D
h 69.7 ft h' 76.79 ft 123.98 ft

r'
97.34 ft

r
131 ft
 Perbandingan Hasil Validasi Template Flare Sizing

Parameter Unit PLNE Template

Mach No., Ma 0.2
Inside Diameter, d m 0.19
Heat Liberated, Q 321923214.6 BTU/hr
Length of flame, L m 21.61
∑▒∆�
m 4.32
∑▒∆�
m 20.53
Distance from flame center to grade-level boundary, D m 37.81
Radius Distance Max., r m 39.96
Flame heigth, h' m 23.42
Flare Stack Height, h m 21.26
Horizontal Distance of flame center from the top of flare stack, xc m 10.26
Vertical Distance of flame center from the top of flare stack, yc m 2.16
ng

PGTB Result
0.2
0.19
9430000 kW
25
4.75
23.63
37.8
40
25.13
22.754
11.81
2.38
Vapour Mass Rate lb/hr
Liquid Mass Rate lb/hr
Vapour Density rv lb/ft3
Vapour Viscosity cP
Liquid Density rl lb/ft3
Diameter Particles D m
ft
Vapor Flow Rate ft3/s
Liquid Flow Rate ft3/s
Gravitational Acc g ft/s2

C(Re)2
C Refer to Fig 12 API 521

Operating Pressure P psi

Operating Temperature T F
R
Drain Volume US gal
ft3
Liquid Holdup AL1 /L
Take Min
Holding and Surge Volume AL2 /L
Cross-sectional area remaining for vapour Av
AV = AT - (AL1 + AL2)
Total drum diameter ht
 169000
31000
0.18
0.01
31
600.00
0.0019686
260.80
0.28
32.2

4.02E+04
0.67

2
300
759.67
500
66.8
66.8
30.0
500
Mach No. Condition
0.2 Continues
0.5 Emergency/Peak
0.7 Maximum