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Cyclohexane Storage Tank (T-102)
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Table: List of Nomenclature for Nitric Acid Storage Tank
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SPECIFICATION Description Equipment Tag Type Orientation Material of Construction No. of Tank Required Design Temperature Design Pressure Tank Volume
Cyclohexane Storage Tank
T-101 Storage Tank Vertical 3.4 Stainless Steels 3 units/s 25 °C 0.1773 MPa 136.9490 m3 DESIGN DIMENSION
Total Tank Height Tank Inside Diameter Tank Outside Diameter Shell Thickness Head Thickness Head Height Crown Radius Knuckle Radius Inlet Nozzle Diameter Inlet Nozzle Thickness Outlet Nozzle Diameter Outlet Nozzle Thickness MECHANICAL DESIGN Actual tank circumference Actual tank diameter Actual inside diameter Actual tank height Actual Crown radius Actual knuckle radius Actual cylinder height Surface area of torispherical head Surface area of torispherical bottom No. of plates for tank circumference No. of plates for tank height No. of plates for tank head No. of plates for tank bottom Total number of plates for the shell Total number of plates for the whole tank
8.5832 4.2916 4.3002 4.3069 8.0790 0.8567 4.2916 0.2575 38.4569 4.0207 41.0097 4.0220
m m m mm mm m m m mm mm mm mm
13.5096 5.8210 5.8124 7.1995 5.8124 0.3487 5.4861 28.0193 28.0193 3 3 3 3 9 15
m m m m m m m m2 m2 plates plates plates plates plates plates
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Data Assumptions:
Mass Flow rate is 3677.1888 kg/hr
24-Hour Operation for 7 days
Material Construction 3.4 Stainless Steel
Operating Pressure at 1 atm
Operating Temperature is 25 °C
Torispherical head and bottom is used.
Design Calculations Volumetric Flowrate ASSUMPTION: The density of cyclohexane at 298.15K is 773.303 kg/m3 (ref. Table 2-305. Page 2-413. Perry’s Chemical Engineer’s Handbook (8th ed.).
Q=
m ρ H 2O
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kg day kg 773.303 3 m
88252.5311 Q=
Q=114.1241
m3 day
Tank Capacity
(
V = 114.1241
m3 ( 3 days ) day
)
V =342.3724 m3 Number of Tanks ASSUPMTION: The available volume of tank available for the market and is specifically applicable for the process is 32,500 gallons or 123025.89 L. N Tank =
342.3724 m3 123025.89 L 1 m3 × tank 1000 L
N Tank =2.7829 ≈ 3 tanks
Tank Capacity of Each Tank 342.3724 m3 V t= 2 tanks V t =114.1241 m 3 Design Volume
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ASSUMPTION: 20% volumetric allowance is considered (ref. Walas, S. M. (1990). Chemical Process Equipment Selection and Design. USA: ButterworthHeinemann).
V Tank =1.2 V t V Tank =1.2(14.1241 m3) V Tank =136.9490 m
3
Total Volume of Tank V Tank =V Cylinder +V Torispherical Head +V Torispherical Bottoms Where: V Cylinder =
π 2 D H 4 i Cylinder
(ref. Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design Volume 6, 4th Edition) V Torispherical Head =0.0809 D 3i (ref. Table 10-60. Page 10-145. Perry, R. & Green D. (2008). Perry’s Chemical
Engineer’s
Handbook,
8th
Edition)
Inside Tank Diameter V Tank =
π 2 D H + 2(0.0809 D 3i ) 4 i Cylinder
V Tank =
π 2 D i (2 D i)+2(0.0809 D 3i ) 4
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V Tank =
π 3 Di +2(0.0809 D 3i ) 4
π 136.9490 m 3= D 3i + 2(0.0809 D 3i ) 2 Di=4.2916 m Height of Cylinder H Cylinder =2( 4.2916 m) H Cylinder =8.5832m Height of the Mixture V Mixture=
π 2 D H 4 i Mixture
π 114.1241 m 3= ¿ 4 H Mixture=7.8894 m Working Pressure P=POptimum + ρg H Mixture
(
P=101,325 Pa+ 773.3030
kg m 9.81 2 ( 7.8894 m ) 3 m s
)(
)
P=161175.1727 Pa∨0.1612 MPa
Design Pressure ASSUMPTION: The design pressure was set to exceed 10% of the operating pressure (ref. Chapter 13.4.1-2, page 810, Coulson and Richardson, Chemical Engineering Design, Vol. 6,4th ed.)
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Design Pressure=1.1 P Design Pressure=1.1 ( 161175.1727 Pa ) Design Pressure=177292.6900 Pa∨0.1773 MPa
Shell Thickness t sp =
PD D i +C 2 Jf −P D
(ref. Eqn. 13.39. Page 815. Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design, Volume 6, 4th Edition) Where:
P= Design Pressure, N/mm2 D= Inside Diameter, mm J= Joint Efficiency, 1.0 (ref. Table. 13.3. Page 813. Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design, Volume 6, 4th Edition) F= Design Stress, N/mm2 (ref. Table. 13.2. Page 812. Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design, Volume 6, 4th Edition) C= Corrosion Allowance, mm (ref. 13.4.8 Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design, Volume 6, 4th Edition)
N (4291.6119 mm) mm2 t sp = + 4 mm N N 2 ( 1 ) 165 − 0.1773 mm2 mm2
(
0.1773
(
) )(
)
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t sp =4.3069mm Torispherical Head t h=
PD RCCS +C 2 Jf +(C s −0.2)
(ref. Eqn. 13.34 Page 819. Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design, Volume 6, 4th Edition) Where: P= Design Pressure, N/mm2 Rc = Crown Radius, m Cs= Stress Concentration Factor for Torispherical Heads D= Inside Diameter, mm J= Joint Efficiency, 1.0 Technological Institute of the Philippines 837 F= Design Stress, N/mm2 C= Corrosion Allowance, mm Crown Radius RC = D i RC =4.2916 m Knuckle Radius Rk =0.06 D i Rk =0.06 ( 4.2916 m ) Rk =0.2575 m
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Stress Concentration C s=
R 1 3+ C 4 Rk
C s=
1 4.2916 m 3+ 4 0.2575 m
( √ ) ( √ )
C s=1.7706 Computing for Head and Bottom Thickness N 0.1773 ( 4291.6119 mm )( 1.7706 ) ( mm ) t = +4 mm N 2 ( 1 ) 165 ( mm )−(1.7706−0.2) 2
h
2
t h=8.0790 mm Outside Tank Diameter DO =Di+ 2t
D O =4.2916 m+2(0.0043)m DO =4.3002 m Height of Torispherical Head H Head=3.5 t+ 0.1935 D o−0.455 t (ref. Sinnot, R.K. (2005). Coulson & Richardson’s Chemical Engineering Design,
Volume
6,
4th
Edition)
H Head=3.5( 8.0790 mm)+0.1935 (4300.225 8 mm)−0.455( 8.0790 mm) H Head=856.6943 mm ≈ 0.856 7 m Total Tank Height
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H Tank =H Cylinder + H Head + H Bottom H Tank =8.5832 m+2 ( 0.8567 m ) H Tank =10.2966 m Nozzle Design General Guidelines
2 For inlet fluids (Liquid or Gas): ρ v ≤1000
2 For outlet gas: ρ v ≤3600
For outlet liquids: v = 1 m/s
kg m−s2
kg m−s2
Nozzle Outlet Diameter ˙ AV = m˙ Q= ρ kg s ˙ Q= kg 773.3030 3 m 1.0214
m ˙ Q=0.0009 s
3
2
m3 π d 0 m 0.0009 = ×1 s 4 s d o =0.0410 m≈ 41.0097 mm Wall Thickness of Nozzle Outlet t no=
Pido +C 2 Jf −Pi
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N 0.1773 ( 41.0097 mm ) ( mm ) t = + 4 mm N N 2 ( 1 ) 165 ( mm )−(0.1773 mm ) 2
no
2
2
t no=4.0220 mm Nozzle Inlet Diameter
ρ v 2=1000
kg m−s2
kg m−s 2 v= kg 773.3030 3 m
√
1000
v=1.1372
m s
Q= AV 2
m3 π d 0 m 0.0013 = ×1 s 4 s d 1=0.0385m ≈ 38.4569 mm Wall Thickness of Nozzle Inlet N 0.1773 (38.4569 mm) ( mm ) t= 2
¿
2(1)¿ ¿
t ¿=4.0207 mm
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Actual Design Circumference of the Tank C Tank =π D o C Tank =π ( 4.3002 m) C Tank =13.5096 m Number of Plates for the Circumference N Circumference =13.5096 m
ft 1 plate ( 3.2181 )( 20 ft ) 1
N Circumference =2.1738 ≈ 3 plates Actual Circumference of the Tank C Tank ,act =3 plates
m plate ( 120plateft )( 13.281 ft )
C Tank ,act =18.2871m Actual Tank Diameter D o , act=
18.2871 m π
Do , act=5.8210m Actual Inside Diameter D i , act=D o ,act −2 t Di , act=5 .8210 m−2(0.0043 m) D i , act=5.8124 m
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Actual Knuckle Radius Rk , act =0.06 D i ,act Rk , act =0.3487 m Actual Crown Radius Rc , act=D i , act Rc , act=5.81 24 m Volume of Shell V Shell =V Tank −2(0.0809 × D 30 , act ) V Shell =136.9490 m 3−2 ¿ V Shell =131.4666 m 3 Height of the Cylinder V Shell =
π 2 D H 4 i ,act cylinders
H cylinders =4.9547 m Number of Plates for the Height of Cylinder N Cylinder =4.9547 m×
3.281 ft 1 plate × 1m 6 ft
N Cylinder =2.7094 ≈ 3 plates Height of the Cylinder Actual
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H Cylinder =3 plates ×
6 ft 1m × 1 plate 3.281 ft
H Cylinder =5.4861 m Actual Height of the Tank H Tank ,act =H Cylinder , act + H Head + H Bottom
H Tank ,act =5.4861 m+ 2(0.8567 m) H Tank ,act =7.1995 m Actual Surface Area of the Torispherical Head A Head=0.264 π Di , act2 A Head=0.264 π ¿ A Head=28.0193m 2 Number of Plates for the Torispherical Head N Head=28.0193 m2 ×
1 plate (6.0957 ×1.8283) m2
N Head=2.5141 m≈ 3 Plates Actual Surface Area of the Torispherical Bottom A Bottom=0.264 π D i ,act2 A Bottom=0.264 π ¿ A Bottom=28.0193 m2 Number of Plates for the Torispherical Bottom N Bottom =28.0193 m2 ×
1 plate 2 (6.0957 ×1.8283)m
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N Bottom =2.5141≈ 3 plates Total Number of Plates for the Shell N Shell =N Circumference × N Cylinder N Shell =3 ×3 N Shell =9 plates Total Number of Plates for the Tank N Total =N Shell + N Head + N Bottom N Total =9+ 3+3 N Total =15 plates Total Tank Volume V Tank =
π 2 D i , act H Cylinder ,act + 0.0809 D 3i , act 4 π V Tank = ¿ 4
V Tank =163.2378 m3 H/D Ratio of the Tank ASSUMPTION: The optimum H/D ratio is 3; however, a range of 0.75 to 5 is common. (ref. Branan, C. (2002). Rules of Thumb for Chemical Engineers, 3rdedition) H 10.2966 m = =2.3992 D 4.2916 m Therefore, the tank dimensions are acceptable. Tank Orientation
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ASSUMPTION: Vessels beyond 40m3 is vertical tank with L/D ratio of a range 0.5 to 1.5 (ref. Branan, C. (2002). Rules of Thumb for Chemical Engineers, 3rd edition). Therefore, the tank orientation is vertical.
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