Page 134 - Pressure Vessel Design Manual

114 Pressure Vessel Design Manual

Sample Problem Nh=-- 4.6fh - 4.6(0.57)200 = 5.01
Vz 104.6
Vertical vessel on skirt:
Structure category = 111
Exposure category =C
4.6fDe 4.6(0.57)7
Basic wind speed, V = 90 mph Nl, = - = 0.175
-
-
Importance factor, I = 1.15 vz 104.6
Equivalent diameter, De =7ft
Overall height, h =200 ft
Empty weight, W = look 15.4fDe - 15.4(0.57)7
Damping coefficient, /3 = 0.01 Nd=-- vz 104.6 = 0.587
Natural frequency, f = 0.57 Hz

Values from Table 3-3:
7.465N1 7.465(3.53)
1 R, = - 1.66 = 0.065
= - =0.1538 (1 f 10.302N1)5'3 - [1+ 10.302(3.53)]
1.65
b = 0.65
c = 0.20

Calculate:
1 1
Z = 0.6h = 0.6(200) = lZOft > Zmin - [1 - .-10.02] z 0.179
5.01 2(5.012)

= 0.893

1 1
D,+h 0.63 = 7 + 200 o,63 = 0.765
1+0.63(7) 1 + 0.63 (w) R"RhRb(0.53 + 0.47Rd)
R=
B
0.065(0.179)0.893(0.53 + 0.47(0.701))
- = 0.893
-
0.01
V,f = 1.467V = 1.467(90) = 132 ft/sec

- 1 + 2(3.5)0.161J0.765 + 0.893 = 1.15
-
1 + 7(0.161)

fL, 0.57(647)
N1=-= = 3.53
V, 104.6 F = %>GfCfAf = 23.846Kz(1.15)0.9Af = 24.68AfK~
where g, = 0.00256K~IV~ = 23.846Kz