(Tech. Specification) Total Tank Height of Shell, H1 m 14.1 Maximum Design Liquid Level, H 2 m Net Design Liquid Height, H 2 m 13.

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Raymond Gregory
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1 A.1.0. Input Design Data Quantity of Tank Nos. 2 Diaeter, D 12 (Tech. Specification) Total Tank Height of Shell, H Maxiu Design Liquid Level, H Net Design Liquid Height, H Refer Annexture - A Noinal Capacity, Q Gross Capacity, Q Effective Capacity, Q (Tech. Specification) Specific Gravity of LDO, G (Tech. Specification) Design Density of liquid, ρ kg/ Design Pressure, P LC Hydrostatic Head Vacuu Pressure, V p kg/ Design Teperature, T C 60 Corrosion Allowance, C 1.5 Joint Efficiency Factor, E Radiography Exaination Material of Construction Spot Radiography IS 2062 Gr. A Maxiu Allowable working Stress,S d kg/c Ref. Cl. No of IS:803 AllowableYield Stress, S y kg/c Ref. Cl. No of IS:803 Width of Shell Plates, W s 1.5 Width of Botto Plates, W b 1.5 Width of Roof Plates, W r 1.5 Yield Stress Miniu, σy Mpa 250 Table 3, Page 5 IS 2062 B.0. DETAILED CALCULATIONS. B.1.0. Calculation of Shell Plate Thickness. 1.1 Nuber of Shell Coures Nos. 10 Calculated Width in Mtr. Sr. No. Shell Course Thickness () Adopted Thickness () 1 Course Course Course Course Course Course Course Course Course Course B.1.1 Thickness of 1 st Course, t = (50xGxDx(H-0.3)/σ a xe) + C Page 22 & 23 of IS:803 Course Under consideration, n 1 Height fro the Botto of course under consideration to the top of curb angle, H= H t - ((n-1) x W s ) 14.1 Thickness of 1st Course, t 7.3 Thickness of 1st Course Considered, ts1 8 B.1.2 B.1.3 B.1.4 Thickness of 2 nd Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 2 Height fro the Botto of course under consideration to the top of curb angle, H 12.6 Thickness of 2nd Course, t 6.67 Thickness of 2nd Course Considered, ts2 8 Thickness of 3 rd Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 3 Height fro the Botto of course under consideration to the top of curb angle, H= H t - ((n-1) x W s ) 11.1 Thickness of 3 rd Course, t 6.04 Thickness of 3rd Course Considered, ts3 6 Thickness of 4 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 4 Height fro the Botto of course under consideration to the top of curb angle, H 9.6 Thickness of 4th Course, t 5.41 Thickness of 4th Course Considered, ts4 6

2 B.1.5 Thickness of 5 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 5 Height fro the Botto of course under consideration to the top of curb angle, H 8.1 Thickness of 5th Course, t 4.78 Thickness of 5th Course Considered, ts5 6 B.1.6 B.1.7 B.1.8 B.1.9 B.1.10 Thickness of 6 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 6 Height fro the Botto of course under consideration to the top of curb angle, H 6.6 Thickness of 6th Course, t 4.15 Thickness of 6th Course Considered, ts 6 5 Thickness of 7 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 7 Height fro the Botto of course under consideration to the top of curb angle, H 5.1 Thickness of 7th Course, t 3.52 Thickness of 7th Course Considered, ts7 5 Thickness of 8 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 8 Height fro the Botto of course under consideration to the top of curb angle, H 3.6 Thickness of 8th Course, t 2.89 Thickness of 8th Course Considered, ts8 5 Thickness of 9 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 9 Height fro the Botto of course under consideration to the top of curb angle, H 2.1 Thickness of 9th Course, t 2.26 Thickness of 9th Course Considered, ts9 5 Thickness of 10 th Course, t = (50xGxDx(H-0.3)/σ a xe) + C Course Under consideration, n 10 Height fro the Botto of course under consideration to the top of curb angle, H 0.6 Thickness of 10th Course, t 1.63 Thickness of 10th Course Considered, ts10 5 Average Thickness Of Tank-Shell 6.28 B.2.0 B.3.0 Botto Plate Thickness. As per Clause No (a), Page 17 of IS 803; All Botto Plate of tank, uniforly resting on the ground, shall have a iniu noinal thickness of 6, Therefore selected thickness of botto plate is 8. Roof Plate Thickness. As per Clause No , Page 36 of IS 803; Miniu noinal thickness of roof plates shall be 5., Therefore selected thickness of Roof plate is 5. B.4.0 Calculation of Design Wind Pressure. Cl. 5.3, page 8 of IS:875 (Part /s Design Wind Speed, V z = V b x k 1 x k 2 x k 3 3) Basic wind speed, V b /s 39 Fig. 1, IS:875 (Part 3) Basic wind speed, V b K/hr Probability Factor (Risk Coefficient ), k As per Table1 IS:875 (Part 3) Terrian, height and structure size factor, k As per Table2 IS:875 (Part 3) Cl , page 12 of IS:875 - Topography factor, k 3 1 (Part 3) Design Wind Speed, V z /s Design Wind Pressure, P d = 0.6 x V z N/ Cl. 5.4, page 12 of IS:875 (Part 3) Design Wind Pressure, P d kg/

3 B.5.0 Stability of Tank Shell against External Loads. As per Clause , Page 23 of IS 803, Stability of tank shell against external loads shall be checked by deterining the axiu height of the shell fro the top curb angle or wind girder that does not buckle under external loading i.e., wind pressure and internal vacuu as follows, Hg=1500t/p x (t/d) 3/2 Where, Hg = Vertical distance between the interediate wind girder and top angle of the shell in t = Average Shell Plate Thickness in height H1 in Average Shell Plate thickness without Corrosion Allowance, t D = Noinal Diaeter of Tank in p = Su of all external pressure acting on the tank shell i.e., design wind pressure (Pd) and internal vacuu (Vp) in kg/2 Su of all external Pressure acting on tank shell i.e. wind pressure (P d ) & Internal vacuu pressure (V p ). Vertical distance between the interediate wind grider and Top curb angle of shell, H g Since Hg (i.e.10.18) is less than noinal height of tank considered as 14, the kg/ Tank is not stable under external loads and there fore Wind Girder is required. No. Of Wind Girder Nos. 1 B.6.0 DESIGN OF WIND GIRDER As per clause of IS:803, the Required iniu section odulus of wind girder shall be deterined by the forula; Z=0.059 D 2 Hg X P / 150,Where Z=Section Modulus in c 3 D= Noral Diaeter of tank in M Hg=Vertical distance between the interediate wind grider and Top curb angle of shell in Mtr. P= Su Of all external pressure acting on the tank shell i.e., design wind pressure & kg/ 2 internal vaccue in kg/ Therefore, Z c Now, consider one wind girder to be provided(shell Thickness, as per detail F(b=250),Table-7 of IS:803; Section odulus is c 3 ) Which is ore than above value. Hence, wind girders On tank shell to be provided to stable the tank B.7.0 Checking of Stress due to Hydrostatic load. Sh = [50x(H-0.3)xD]/t 3/7 Min. UTS Where, Sh = Hydrostatic Stress in kg/c2 H = Height of tank in D = Noinal Diaeter of the tank in t = Average Shell Plate Thickness in (without corrosion allowance) Average shell plate thickness without Corrosion allowance, t 4.78

4 Therefore, Putting the values in Above Eqn., we get L.H.S., S h kg/c Ultiate Tensile Strength of IS 2062 Mpa 410 Page 5, Table 3 IS 2062 Ultiate Tensile Strength of IS 2062 kg/c R.H.S, i.e. 3/7 of UTS kg/c Since L.H.S < R.H.S, The average shell plate thickness under Hydrostatic load is safe. B.8.0 Selection of Curb Angle on Tank Shell. As per Clause , Page 26 of IS 803, for a tank of diaeter over 10 and upto and including 18, the size of roof curb angle required is ISA 65X65X8 thk. This will be attached to the upper edge of the external surface of the tank shell. Hence, Actual Curb Angle on tank shell Provided is ISA 65X65X8 thk B.9.0 Calculation of Structurals. B DESIGN OF RAFTER (Refer Annexture -B) : Sizing Calculation and Strength Checking : Roof area of Tank, Ar 2 TT x r x s in 2 Where r = Radius of conical roof in Mtr s = Slant length of conical roof in Mtr Thickness of Roof 5 considering the slope (1:16),slant height.s= Un-corroded wt. of roof plate, Wruc Kg Roof load per unit area, Wa = Weight of roof / Roof Area = (Wruc/Ar) in kg/c2 Therefore, Putting the values in Above Eqns., we get Ar Wd (Dead Load Per Unit Area) kg/ Considering 20 % Higher for Roof Accessories kg/ Unifor Live Load To Be Considered During Designing kg/ Wa (Total Load Per Unit Area) kg/ Wa (Total Load Per Unit Area) kg/c Maxiu rafter Spacing, L = t X (2f/Wa)^1/2 c Where, t = Thickness Roof plate c 0.50 f = Allowable Stress Value, Kg/ c.sq Wa= Total Load per Unit area for roof kg/c Miniu No. of rafters, n = 2 r /L Nos Actual No. of rafters provided, n Nos. 26 SinceasperCl.6.4.4of IS:803 the axiu spacing shall be 2000, we have provided 22 no. of rafters. Spacing or Rafter, = D/ No. of rafter 1451 Refer Annexture-B B Checking of rafter Size Main Rafter Considering, Rafter Meber as ISMC 150 with ; Section Modulus of c3; Moent of Inertia of c4. Unit Weight of Rafter Selected Kg/Mtr 16.4 Length of Rafter, L1 c 571 Refer Annexture-B

5 There fore roof load per unit length of rafter, W = Wa / nx Length of Rafter Kg/C The Maxiu Bending oent M ax. =( W L^2) /8 Kg-c Section Modulus, Z = M ax. / f Cu. C 8.63 AddingWeight of the ain rafter to the rafter Load W1 = W + Unit Wt of Rafter Kg/C The Maxiu Bending oent M ax. = ( W L^2 ) /8 Kg-c Indused Section Modulus, Z = M ax. / f Cu. C The Channel sections used ISMC-150 Selected for ain rafter has a section odulus of Zxx = Cu.C Since, Induced Section Modulus (i.e c3) is less than that of the eber considered (i.e c3); So the rafter is saft under Bending B Deflection Checking As per Bea Forulas, Page384 of "Process Equipent Design" by Brownell & Young; Max. Vertical Deflection, δ = (5 x W ra L 4 a )/(384ExI a )c, and as per Cl , Page 34 of IS:800,liiting Vertical deflection is given as δ=l/325 c. Deflection Checking for Rafter-A. Unifor load on Rafter-, W ra kg/c Length of Rafter, L c 571 Moent of Inertia for Rafter, I c SP:6 (1), Page 6 Youngs Modulus of Elasticity, E MPa Cl.1.3, Page 15 of IS:800 Youngs Modulus of Elasticity, E kg/c Max. Vertical Deflection for Rafter-A, δ a = (5 x W ra L 4 a )/(384ExI a ) c Liiting Vertical Deflection for Rafter-A, δ l =L a /325 c Max. Deflection is under perissible liit, hence eber considered for Rafter i.e. ISMC 150 is Safe Under loading and delflection. B.9.2 Crown Plate According to clause of IS:803 the diaeter of crown plate & the diaeter of flat surface of crawn plate required for & 630 respectively. The crown plate selected is 20 Thick MS plate 12 Mtr. Dia tank is 960 B.9.3 B Design of Center Colun Sizing Calculation and Strength Checking: Considering Center Colun configuration as a coposite section of ISMC of ISMC 200 & 250 Wt.of ISMC 200 Per unit lenght Kg/Mtr 22.1 Wt.of ISMC 250 Per unit lenght Kg/Mtr 30.4 Page 360, of "Process As per above configuration ean radius of gyration, R =(R xx + R yy )/2 Equipent & Design" by c Brownell & Young. Radius of Gyration along X-axis, R xx c 9.94 Radius of Gyration along Y-axis, R yy c 8.03 Length of Centre Colun considered, L cc c Maxiu Slenderness Ratio to avoid bukling, λ Table 3.1 of IS:800 Induced Slenderness Ratio, λ= L cc /R Induced Slenderness ratio is less than Max. Perissible, hence satisfactory Now, As per Table 5.1, Page 39 of IS:800, interpolation with respect to the above slenderness ratio & yield stress i.e 250 MPa, Perissible Stress in axial copression, σ ac MPa 41

6 Perissible Stress in axial copression, σ ac kg/c Induced Copressive stress, σ ic = Total copressive load(w c )/Cross Sectional Area of centre colun(a c ) Total Copressive Load, W c = (Weight of roof +unifor live load + wt. of rafter)/2 + Self Weight of central colun kg/c 2 kg Considering it is siply supported bea supporting on circufrential shell & on central coluns, so the load is equally divided on cirufrential shell & central colun Total Copressive Load, W c kg Cross Sectional Area of Centre Colun, A c =(A ISMC250 + A ISMC200 ) c SP:6 (1), Page 6 Induced Copressive stress, σ ic kg/c Since σ ic < σ ac, Centre colun Provided is a coposite section of ISMC 200 & ISMC 250 B.10 Weight Calculation for Tank. Total Weight of Shell, W s kg Weight of Shell Without Corrosion Allowance, W sca kg Weight of Roof, W r = Weight of plates + Weight of Rafters + Weight of Girders + kg Weight of crown Plate Weight of Roof Plate, W rp kg Total Weight of Structure,Approx kg 4000 Total Weight of Botto of Tank, W b kg Considering Weight of Coplete Staircase & hand railing, approx. W str kg 1800 Total Weight Of Nozzles,Approx. kg 350 Total Weight of Wind Girder kg 1159 Approxiate Total Weight of EptyTank, W total kg

MECHANICS OF MATERIALS

00 The McGraw-Hill Copanies, Inc. All rights reserved. T Edition CHAPTER MECHANICS OF MATERIALS Ferdinand P. Beer E. Russell Johnston, Jr. John T. DeWolf Lecture Notes: J. Walt Oler Texas Tech University