Rectangular Tank_Design Exel

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1 1

DOCUMENT NO. : OMPL-DC-204 30-Apr-15

COVER PAGE CHKD. APPD.

SNS CP

P.O. NO. : 4608183-000/7.12.050/I06

CUSTOMER : AIR LIQUIDE GODREJ

EQUIPMENT :

JOB NO. : V-505

MFR'S SERIAL NO. : 001345

TOTAL PAGES : 11

(INCL. THIS PAGE)

MECHANICAL DESIGN CALCULATIONS

FOR

RECTANGULAR TANK FOR DIRECT COOILNG WATER

Tag No.: 105F06

DOCUMENT NO. : OMPL-DC-204

REVISION NO. OF THIS SHEET INDICATES REVISION NO. OF ENTIRE DOCUMENT

1 30-Apr-15 ISSUE FOR APPROVAL SNS CP

0 18-Mar-15 ISSUE FOR APPROVAL SNS CP

REV. DATE CONTENT CHKD APPD

ORIENTAL MANUFACTURERS

RECTANGULAR TANK FOR DIRECT COOILNG WATER

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RECTANGULAR TANK CALCULATION SHEET FOR TAG 104F04

I. DESIGN PARAMETERS:

- Code Design : API 650 & Roark's Formulas

- Design pressure 2169.5 (Annexure-1)

= 21.28 kPa

- Design temperature : 100

- Operating pressure : ATM

- Operating temperature : 50

- Corrosion Allowance C.A : 0mm

- Liquid Specific Gravity : 1.00

- Joint Efficiency : 0.85 (For Shell)

: 1.00 (For Roof & Bottom)

- Elastic Modulus E :2.74*E+7 psi

= 188916350 kPa

MATERIAL SPECIFICATION: :

- Shell, Roof & Bottom : SS 304L

- Allowable Stress 16700.1psi

= 115143 kPa

- Allowable Bending Stress 11022.066 psi

= 75994.47 kPa

- Nozzle Neck : A 182 F 304L

- Flange : A 182 F 304L

- Pipe Fittings : A 312 TP 304L

- Bolts & Nuts : A 193 Gr B7 / A 194 Gr. 2H

- Stiffeners : SS 304L TANK GEOMETRY: - Height H : 1500mm - Length L : 1600mm - Width W : 1400mm P_d : _kg/m2 o_C o_C Sa : Sb : Width (W) H ei gh t (H )

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II. DESIGN

II.1 Side Wall Plate Calculation (Height x Length) II.1.1 Wall Thickness Calculation

(As per Roark's Formulas 7Th Ed, Table 11.4 Case 1a)

Vertical length without reinforced a : 500 mm Horizontal length without reinforced b : 533 mm

Ratio, a/b : 0.94

α = 0.0444

β = 0.2874

Required thickness (Formula No.-3 of Ch. 13 -Design Of Rectangular Tank)

= 4.78 mm

Adopted thickness 6.00 mm

Maximum deflection (Formula No.-4 of Ch. 13 -Design Of Rectangular Tank)

= 1.87 mm

<

1.87mm < 3mm

Therefore, adopted thickness is satisfactory II.1.2 Top Edge Stiffener

Ref: Formula No.-12 & 14 of Ch. 13 -Design Of Rectangular Tank

= 0.32 kN/m

= 3.40 kN/m

= 118.64

= 0.0119

Moment inertia of used stiffener (angle 50x50x6):

= 12.8

Therefore, Top edge stiffener is satisfactory II.1.3 Horizontal Stiffener

= 1265.55

= 0.1266

= 12.8

Therefore, Horizontal stiffener is satisfactory

t_r = Sqrt(β*P_d*b2_)/S b) + C.A ta : Ymax = α*Pd*b 4_/(E*t a 3₎

Y_max 1/2 t_a _{(Last para. Of Design Procedure w/o stiffner, Ch. 13} -Design Of Rectangular Tank)

R1 = 0.03*Pd*a R2 = 0.32*Pd*a

Moment inertia required: (Ref: Formula No.-9 of Ch. 13 -Design Of Rectangular Tank ) Jmin = R1*b

4_/(192*E*t

a) mm4

cm4

J_x = J_y _cm4

Moment inertia required: (Ref: Formula No.-9 of Ch. 13 -Design Of Rectangular Tank ) J_min = R₂*b4_/(192*E*t a) mm4 cm4 Jx = Jy cm4 H ei gh t (H ) a b Length (L) a b Stiffeners a b a b

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II.1.4 Vertical Stiffener

288.70 mm

= 0.06 kNm

Required section modulus:

= 5.27E-07

= 0.53

Section modulus of used stiffener (angle 50x50x6):

Z = 3.61

Therefore, Vertical stiffener is satisfactory II.2 Side Wall Plate Calculation (Height x Width) II.2.1 Wall Thickness Calculation

Ratio, a/b : 1.61

α = 0.0906

β = 0.5172

Required thickness (Formula No.-3 of Ch. 13 -Design Of Rectangular Tank)

= 5.62 mm

Maximum deflection (Formula No.-4 of Ch. 13 -Design Of Rectangular Tank)

= 2.24 mm

<

2.24mm < 3mm

Therefore, adopted thickness is satisfactory II.2.2 Top Edge Stiffener

Ref: Formula No.-12 & 14 of Ch. 13 -Design Of Rectangular Tank

= 0.48 kN/m

= 5.11 kN/m

Moment inertia required: (Ref: Formula No.-9 of Ch. 13 -Design Of Rectangular Tank )

= 104.32

= 0.0104

= 12.8

Therefore, Top edge stiffener is satisfactory

Maximum bending moment at Hy = 0.5774*amax = (Pg. 272 Adding vertical stiffner - Dist. For maxmium bending moment)

Maximum bending moment: (Ref: Formula No.-16 of Ch. 13 -Design Of Rectangular Tank ) Mmax = 0.0642*Pd*b*Hy2 Zr = Mmax/Sa mm3 cm3 cm3 t_r = Sqrt(β*P_d*b2_)/S b) + C.A ta : Ymax = α*Pd*b4/(E*ta3)

R₁ = 0.03*P_d*a R₂ = 0.32*P_d*a J_min = R₁*b4_/(192*E*t a) mm4 cm4 Jx = Jy cm4 H ei gh t (H ) a b a b Stiffeners a b a b Width (W)

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II.2.3 Horizontal Stiffener

Moment inertia required: (Ref: Formula No.-9 of Ch. 13 -Design Of Rectangular Tank )

= 1112.76

= 0.1113

= 12.8

Therefore, Horizontal stiffener is satisfactory II.2.4 Vertical Stiffener

432.98 mm

= 0.12 kNm

Required section modulus:

= 1.04E-06

= 1.04

Section modulus of used stiffener (angle 50x50x6):

Z = 3.61

Therefore, Vertical stiffener is satisfactory II.3 Roof Plate Calculation

Loads on roof plate:

- Roof area: = 2.24

- Live load: = 1.5 kPa

- Roof weight: = 156 kg

- Roof structure weight: = 100 kg

- Roof Equipment weight: = 100 kg

- Dead load: = 1.6 kPa

Total load on roof plate: = 3.1 kPa

Distance without reinforced in width a : 700 mm Distance without reinforced in length b : 533.333333 mm

Ratio, a/b : 1.31

α = 0.0703

β = 0.4194

Required thickness: (Formula No.-3 of Ch. 13 -Design Of Rectangular Tank)

= 2.19 mm

Maximum deflection: (Formula No.-4 of Ch. 13 -Design Of Rectangular Tank)

= 0.43 mm

<

0.43mm < 3mm

Therefore, adopted thickness is satisfactory

Jmin = R2*b4/(192*E*ta) mm4

cm4

Jx = Jy cm4

Maximum bending moment at Hy = 0.5773*amax = (Pg. 272 Adding vertical stiffner - Dist. For maxmium

bending moment)

Maximum bending moment:(Ref: Formula No.-16 of Ch. 13 -Design Of Rectangular Tank ) Mmax = 0.0641*Pd*b*Hy2 Z_r = M_max/S_a _m3 cm3 cm3 m2 tr = Sqrt(β*Pd*b2)/Sb) + C.A ta : Ymax = α*Pd*b 4_/(E*t a 3₎

Stiffeners W id th ( W ) Length (L) a a b b

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II.4 Bottom Plate Calculation

Distance without reinforced in width a : 700.000 mm Distance without reinforced in length b : 533.333 mm

Ratio, a/b : 1.31 α = 0.0703 β = 0.4194 Required thickness: = 5.78 mm Adopted thickness 6.00 mm

Maximum deflection: (Formula No.-4 of Ch. 13 -Design Of Rectangular Tank)

= 2.96 mm

<

2.96mm < 3mm

tr = Sqrt(β*Pd*b2)/Sb) + C.A

ta :

Ymax = α*Pd*b4/(E*ta3)

Ymax 1/2 ta (Last para. Of Design Procedure w/o stiffner, Ch. 13

-Design Of Rectangular Tank)

a b a b Stiffeners a b a b W id th ( W ) Length (L)

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RECTANGULAR TANK CALCULATION SHEET

- Code Design : API 650 & Roark's Formulas - Design pressure Full water + 5 kPag

= 16.77 kPa - Design temperature : 10 - Operating pressure : ATM - Operating temperature : 50 - Corrosion Allowance C.A : 0 mm - Liquid Specific Gravity : 0.99

: 1.00 (For Roof & Bottom) - Elastic Modulus E : 2.74*E+7 psi

= 199947962 kPa

retangular MATERIAL SPECIFICATION: :

- Allowable Stress 16700.1 psi = 115143 kPa - Nozzle Neck : A 182 F 316L - Flange : A 182 F 316L - Pipe Fittings : A 312 TP 316L

- Bolts & Nuts : A 193 Gr B7 / A 194 Gr 2 - Stiffeners : SS 316L TANK GEOMETRY: - Height H : 1200 mm - Length L : 1100 mm - Width W : 1000 mm P_d : o_{C / AMB} o_C S_a: Width (W) H ei gh t (H )

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II. DESIGN

Ratio, a/b : 1.09 α = 0.0522 β = 0.3278 Required thickness = 3.80 mm Adopted thickness 6.00 mm Maximum deflection = 1.86 mm < 1.86mm < 3mm

II.1.2 Top Edge Stiffener

= 0.30 kN/m = 3.22 kN/m Moment inertia required:

= 119.93 = 0.0120 Moment inertia of used stiffener (angle 50x50x8):

= 16.3

Moment inertia required:

= 16.3

t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a R₁ = 0.03*P_d*a R₂ = 0.32*P_d*a J_min = R₁*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4 J_min = R₂*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4 H ei gh t (H ) a b Length (L) a b Stiffeners a b a b

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346.38 mm Maximum bending moment:

= 0.07 kNm Required section modulus:

= 6.16E-07 = 0.62 Section modulus of used stiffener (angle 50x50x8):

Z = 4.68

Therefore, Vertical stiffener is satisfactory

II.2 Side Wall Plate Calculation (Height x Width) II.2.1 Wall Thickness Calculation

= 16.3

Maximum bending moment at H_y = 0.5773*a_max=

M_max = 0.0641*P_d*b*H_y2 Z_r = M_max/S_a _mm3 cm3 cm3 t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a R₁ = 0.03*P_d*a R₂ = 0.32*P_d*a J_min = R₁*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4 H ei gh t (H ) a b a b Stiffeners a b a b Width (W)

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= 16.3

Z = 4.68

II.3 Roof Plate Calculation

- Roof area: = 1.1

- Live load: = 1.5 kPa Assumed - Roof weight: = 102 kg

- Roof structure weight: = 100 kg Assumed - Roof Equipment weight: = 100 kg Assumed - Dead load: = 2.7 kPa

Total load on roof plate: = 4.2 kPa Distance without reinforced in width a : 500 mm Distance without reinforced in length b : 550 mm

Ratio, a/b : 0.91 α = 0.0444 β = 0.2874 Required thickness: = 1.78 mm Adopted thickness 6.00 mm Maximum deflection: = 0.39 mm J_min = R₂*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4

M_max = 0.0641*P_d*b*H_y2 Z_r = M_max/S_a _mm3 cm3 cm3 m2 t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Stiffeners W id th ( W ) Length (L) a a b b

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<

0.39mm < 3mm

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Distance without reinforced in width a : 500 mm Distance without reinforced in length b : 550 mm

Ratio, a/b : 0.91 α = 0.0444 β = 0.2874 Required thickness: = 3.56 mm Adopted thickness 6.00 mm Maximum deflection: = 1.58 mm < 1.58mm < 3mm

t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a a b a b Stiffeners a b a b W id th ( W ) Length (L)

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TANK CALCULATION SHEET

= 199947962 kPa

- Allowable Stress 16700 psi = 115142 kPa - Nozzle Neck : A 182 F 316L - Flange : A 182 F 316L - Pipe Fittings : A 312 TP 316L

- Bolts & Nuts : A 193 Gr B8M / A 194 Gr 8M - Stiffeners : SS 316L TANK GEOMETRY: - Height H : 2000 mm - Length L : 5700 mm - Width W : 1250 mm P_d : o_{C / AMB} o_C S_a: Width (W) H ei gh t (H )

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II. DESIGN

= 29.4

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Z = 6.26

= 29.4

M_max = 0.0641*P_d*b*H_y2 Z_r = M_max/S_a _mm3 cm3 cm3 t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a R₁ = 0.03*P_d*a R₂ = 0.32*P_d*a J_min = R₁*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4 H ei gh t (H ) a b a b Stiffeners a b a b Width (W)

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= 29.4

Z = 6.26

- Roof area: = 7.125 - Live load: = 1.5 kPa - Roof weight: = 386 kg - Roof structure weight: = 116 kg - Roof Equipment weight: = 120 kg - Dead load: = 0.9 kPa Total load on roof plate: = 2.4 kPa Distance without reinforced in width a : 1250 mm Distance without reinforced in length b : 712.5 mm

Ratio, a/b : 1.75 α = 0.0989 β = 0.5559 Required thickness: = 2.40 mm Adopted thickness 6.00 mm Maximum deflection: = 1.39 mm J_min = R₂*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4

M_max = 0.0641*P_d*b*H_y2 Z_r = M_max/S_a _mm3 cm3 cm3 m2 t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Stiffeners W id th ( W ) Length (L) a a b b

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<

1.39mm < 3mm

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t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a a b a b Stiffeners a b a b W id th ( W ) Length (L)

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TANK CALCULATION SHEET

= 199947962 kPa

- Allowable Stress 16700 psi = 115142 kPa - Nozzle Neck : A 182 F 316L - Flange : A 182 F 316L - Pipe Fittings : A 312 TP 316L

- Bolts & Nuts : A 193 Gr B8M / A 194 Gr 8M - Stiffeners : SS 316L TANK GEOMETRY: - Height H : 2000 mm - Length L : 2100 mm - Width W : 1250 mm P_d : o_{C / AMB} o_C S_a: Width (W) H ei gh t (H )

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II. DESIGN

Vertical length without reinforced a : 500.0 mm Horizontal length without reinforced b : 525 mm

= 121.80 = 0.0122 Moment inertia of used stiffener (Flat bar 65x6):

= 13.7

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= 6.00E-07 = 0.60 Section modulus of used stiffener (Flat bar 65x6):

Z = 4.2

M_max = 0.0641*P_d*b*H_y2 Z_r = M_max/S_a _mm3 cm3 cm3 t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a R₁ = 0.03*P_d*a R₂ = 0.32*P_d*a J_min = R₁*b4_/(192*E*t a) mm4 cm4 H ei gh t (H ) a b a b Stiffeners a b a b Width (W)

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= 13.7

= 4.76E-07 = 0.48 Section modulus of used stiffener (Flat bar 65x6):

Z = 4.2

- Roof area: = 2.625 - Live load: = 1.5 kPa - Roof weight: = 174 kg - Roof structure weight: = 116 kg - Roof Equipment weight: = 120 kg - Dead load: = 1.5 kPa Total load on roof plate: = 3.0 kPa Distance without reinforced in width a : 1250 mm Distance without reinforced in length b : 700 mm

Ratio, a/b : 1.79 α = 0.1011 β = 0.5662 Required thickness: = 2.70 mm Adopted thickness 6.00 mm J_x = J_y _cm4 J_min = R₂*b4_/(192*E*t a) mm4 cm4 J_x = J_y _cm4

M_max = 0.0641*P_d*b*H_y2 Z_r = M_max/S_a _mm3 cm3 cm3 m2 t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Stiffeners W id th ( W ) Length (L) a a b b

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Maximum deflection:

= 1.70 mm <

1.7mm < 3mm

Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a t_r = Sqrt(β*P_d*b2_)/S a) + C.A t_a : Y_max = α*P_d*b4_/(E*t a3) Y_max 1/2 t_a a b a b Stiffeners a b a b W id th ( W ) Length (L)

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DESIGN CALCULATION SHEET FOR TAG 104F07

Design Calculation For Top Portion Of The Tank

I. Inputs :

1 LENGTH OF RECTANGULAR TANK L 790 mm 2 WIDTH OF RECANGULAR TANK W 790 mm 3 HEIGHT OF RECTANGULAR TANK H 595 mm 4 THICKNESS OF MATERIAL USED t 5 mm 5 CORROSION ALLOWANCE c 0 mm

6 Ws 400 Kg

7 - SA-240 Typ 304L

8 DENSITY OF THE MATERIAL OF TANK ρc 8000 9 DENSITY OF THE OPERATING LIQUID ρw 1000 10 ELASTIC MODULUS OF THE MATERIAL E 19264.00 11 YIELD STRESS OF THE MOC Sy 1757.9 13 ALLOWABLE BENDING STRESS 1160.2

Calculation:

Total Volume of the tank V =

371339500 0.37

Empty weight of the tank with 5 mm thickness We = 275 kg Weight of the liquid in the tank Wl = V x ρw

371 kg Total weight of tank with liquid W = We + Wl + Ws

1074 kg The Analysis of the tank shell will be done in three

parts;-1 Thickness requirement for the top of the tank 2 Thickness requirement for the length of the tank

This thickness analysis would be followed by the check for structural requirement for stiffener. APPROXIMATE WEIGHT OF STRUCTURE

AND AND NOZZLES

MATERAIL OF CONSTRUCTION OF THE TANK kg/m3 kg/m3 kg/mm2 kg/cm2 σ_b _kg/cm2

Rectangular tanks are designed for static head of the liquid. No internal or external pressure is considered. In order to satisfy thickness requireement, external stiffeners are provided so that the tank plates do not buckle under the stress developed due to no liquid head.

L × W × H

mm3

m3

The structural calculation for the adequacy of the structure for lifting of the tank and for operating condition with full liquid along with adequacy check for the lifting lug shall conclude the calculations.

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Total vertical load on the bottom plate Wl = 371 kg Total area of the bottom plate Ab = L X W

Ab = 624100 Ab = 0.6241 Hence the load per unit area of the plkate q = Wl/Ab q = 595

0.000595 Divide length in 3 parts and width in 2 parts

The maxmium unstiffened length becomes a = L/2

395 mm The maxmium unstiffened width becomes b = W/2

395 mm Hence the ratio of length to width a/b = 1.000

Interpolating the value for a/b = 1.143 0.308 0.139 α = 0.014

Hence from this value an as per Roark's equation for stress, as per the case mentioned above, -1142982.981

-114.2982981 Induced stress at the centre

σ =

514676.547 51.5

Maximum deflection of the plate Y =

-0.08 mm Considering the allowable deflection as a/324 1.22 mm Since the deflection caused is less than the allowable deflection, design is acceptable.

As per Roark's formula for stress and strain ,Seventh Edition, Table 11.4, Page 508, Case No.8 For a rectangular plate with all edges fixed and load distributed uniformly over the entire plate The base of the tank can be assumed too be a plate with uniform loading.

mm2 m2 kg/m2 kg/mm2 ß_{1 =} ß_{2 =}

Maximum bending stress at the centre of long

edge = -ß1qb 2_/t2 _kg/m2 kg/cm2 ß₂qb2_/t2 kg/m2 kg/cm2

Since the induced stress is less then the allowable stress the provided thickness with the stiffener ring arrangment is accepted.

-αqb4/_Et3

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Where Ps = ρh

h:-height of the element ρ:-density of liquid

Again in the case the length would be divided into 2 parts and height into 2 parts. Thus,the unstiffened length becomes a = L/2

395.00 mm b = H/2

297.5 mm Now for the height, we go as per the following distribution

Bottom Section = 1200

The following value can be tabulated

a/b = 1.33 0.513 0.122 0.082 0.126 0.178 α = 0.011 Maximum bending stress induced at the vertical centre

Maximum bending stress induced at the horizontal centre

Section Bottom -108.01 25.73 -17.33 26.64 -37.59 0.02 mm L /324 1.22 mm

The Maximum stress generated in the plate 108.01 Design allowable stress 1160.2

Provided plates are safe in deflection check.

Since the static pressure increases downwards, more stiffing would be required at the part of the tank. The static pressure along the length is given the relation.

Hence in the case, for a height of 1200mm, the static pressure increses from 0 kg/m2_{at top to 1200}

kg/m2_{at the bottom of the tank.}

kg/m2

As per Roark's formula for stress and strain 7th edition table 11.4, case 8d For a rectangular plate fix on all sides with uniformly decreasing load parallel to side plate.

ß₁= ß₂= ß₃= ß₄= ß₅= σb = -ß₁qb2_/t2 σb = -ß₅qb2_/t3 -ß₁qb2_/t2 kg/cm2 ß₂qb2_/t2 kg/cm2 -ß₃qb2_/t2 _kg/cm2 ß₄qb2_/t2 _kg/cm2 -ß₅qb2_/t2 _kg/cm2 y = αqb4_/Et3

σ

_max

=

_kg/cm2

σ

_b

=

_kg/cm2

Since the induced stress in the plate is less than the allowable, the provided thickness and stiffening is safe.

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Design Calculation For Bottom Portion Of The Tank

I. Inputs :

1 LENGTH OF RECTANGULAR TANK L 790 mm 2 WIDTH OF RECANGULAR TANK W 790 mm 3 HEIGHT OF RECTANGULAR TANK H 370 mm 4 THICKNESS OF MATERIAL USED t 5 mm 5 CORROSION ALLOWANCE c 0 mm

6 Ws 300 Kg

7 - SA-240 Typ 304L

8 DENSITY OF THE MATERIAL OF TANK ρc 8000 9 DENSITY OF THE OPERATING LIQUID ρw 1000 10 ELASTIC MODULUS OF THE MATERIAL E 19264.00 11 YIELD STRESS OF THE MOC Sy 1757.9 13 ALLOWABLE BENDING STRESS 1160.2

Calculation:

Total Volume of the tank V =

230917000 0.23

Empty weight of the tank with 5 mm thickness We = 275 kg Weight of the liquid in the tank Wl = V x ρw

231 kg Total weight of tank with liquid W = We + Wl + Ws

833 kg The Analysis of the tank shell will be done in three

parts;-1 Thickness requirement for the top of the tank 2 Thickness requirement for the length of the tank

This thickness analysis would be followed by the check for structural requirement for stiffener. APPROXIMATE WEIGHT OF STRUCTURE

AND AND NOZZLES

MATERAIL OF CONSTRUCTION OF THE TANK kg/m3 kg/m3 kg/mm2 kg/cm2 σ_b _kg/cm2

Rectangular tanks are designed for static head of the liquid. No internal or external pressure is considered. In order to satisfy thickness requireement, external stiffeners are provided so that the tank plates do not buckle under the stress developed due to no liquid head.

L × W × H

mm3

m3

The structural calculation for the adequacy of the structure for lifting of the tank and for operating condition with full liquid along with adequacy check for the lifting lug shall conclude the calculations.

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Where Ps = ρh

h:-height of the element ρ:-density of liquid

Again in the case the length would be divided into 2 parts and height into 2 parts. Thus,the unstiffened length becomes a = L/2

395.00 mm b = H/2

370 mm Now for the height, we go as per the following distribution

Bottom Section = 1200

The following value can be tabulated

a/b = 1.07 0.264 0.093 0.076 0.089 0.161 α = 0.008 Maximum bending stress induced at the vertical centre

Maximum bending stress induced at the horizontal centre

Section Bottom -53.54 18.87 -15.32 17.96 -32.67 0.02 mm L /324 1.22 mm

The Maximum stress generated in the plate 53.54 Design allowable stress 1160.2

Provided plates are safe in deflection check.

Since the static pressure increases downwards, more stiffing would be required at the part of the tank. The static pressure along the length is given the relation.

Hence in the case, for a height of 1200mm, the static pressure increses from 0 kg/m2_{at top to 395}

kg/m2_{at the bottom of the tank.}

kg/m2

As per Roark's formula for stress and strain 7th edition table 11.4, case 8d For a rectangular plate fix on all sides with uniformly decreasing load parallel to side plate.

ß₁= ß₂= ß₃= ß₄= ß₅= σb = -ß₁qb2_/t2 σb = -ß₅qb2_/t3 -ß₁qb2_/t2 kg/cm2 ß₂qb2_/t2 kg/cm2 -ß₃qb2_/t2 _kg/cm2 ß₄qb2_/t2 _kg/cm2 -ß₅qb2_/t2 _kg/cm2 y = αqb4_/Et3

σ

_max

=

_kg/cm2

σ

_b

=

_kg/cm2

Since the induced stress in the plate is less than the allowable, the provided thickness and stiffening is safe.

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WIND LOAD CALCULATION

As per IS-875 Part3

Basic wind speed for the site

44 m/sec

158.4 km/hr

Risk Factor k1 = 1.07

Terrain Fctor k2 = 1.05

Topography Factor k3 = 1

Overall height of vessel H = 1470 mm

Design wind speed

49.4 m/sec

The Effective Wind Pressure

1466.23 The area exposed to the wind along length/width Al =

1.176

Total wind force acting on along length Fl =

1724.29 N `

Total wind force acting on along width Fw =

689.20 N

Hence the maximum of the wind load Pw = Fl

1724.29 N wind moment Mw = 258.4 kg-m V_b= V_z= k1*k2*k3*Vb P_z= 0.6 x Vz2 N/m2 L × H m2 Al * P_z Aw * P_z

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SEISMIC LOAD CALCULATION

As per 1893 part 4,2005

Total weight of the tank full of liquid W = 1074 kg Seismic zone as specified by the client Z = III

Z = 0.16

Sa/g = 2.5

Importance factor as per Table 2 of IS 1893 I = 1.5

R = 3

Hence the horizontal seismic coefficient Ah =

R/I

Ah = 0.10

The total seismic force acting on the vessel Fs = W × Ah 107.38 kg

Thus the maximum of wind and seismic Fh = max(Pw,Fs)

175.77 kg

CG from the bottom of vessel = 870 mm

The vertical effect of wind/ seismic force F =

= 193.6 kg

= 1898.9 N

Zone Factor as per Annex. A in accordance to Table 2 of IS 1893 Part I

Spectral acceleration coefficient as in Annex. B : (Max)

Response reduction factor as per table 3 of IS 1893

Z/2 × Sa/g

Fh × (CG distance from bottom/ distance between support)

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ANCHOR CHAIR CALCULATION

Anchor Gusset

(Pressure Vessel Book, By Bednar)

No. Of Gusset N = 2

Load On Each Gusset f = 949.45 N

Height Of the Gusset h = 400 mm

Width Of The Gusset d = 350 mm

Distance Between Gusset b = 175 mm

Gusset Angle α = 51 degree

Dimesion a of base plate a = 235 mm

Force bearing width of base plate 100 mm (Client to confirm) MOC of Gusset IS 2062 Gr. B

Yield Stress

Allowable compressive stress

Yield Stress Sy = 240 MPa

Sa = 108 MPa

MOC of Base plate IS 2062 Gr. B

Yield Stress Fy =

240 MPa 34809.12 Psi fc = _{1450.38 Psi}10 MPa

Provided Bottom Plate Thickness t = 16 mm

Corroded Bottom Plate Thickness tc = 16 mm

Required Gusset Thickness =

0.56 mm

Hence the Provided thickness is Sufficient.

when b/d = 0.5

Therefore ß = 0.12 (From Roark's formula table 11.4 case no. 7d) Uniform load

q = _0.081F/db Max. stress to base plate (S) : =

4.64

Therefore the provided base plate is safe Allowanle Compressive Strength = 0.45 x Sy

Compressive Strength of the structure (Client To Confirm)

f(3d-b) / (Sa*b^2 × sina^2)

Since the base plate has to accommodate one or more anchor bolt therefore we are analyzing the base plate as a uniformly loaded rectangular plate with one edge free and three supported.

N/mm2 ßqb2/tc2

N/mm2 Which is less than allowable compressive stress 108 N/mm2

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