• Author / Uploaded
• Sandeep Patil

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STEEL STRUCTURAL CALCULATION REPORT

00 REV. DATE N° DATE

XX

XX XX DESCRIZIONE DESCRIPTION

EMESSO CONTROLLATO ISSUED BY

CONTROLLED BY

APPROVATO APPROVED BY

1

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CALCULATION ASSUMPTION

1.1 SCOPE This report describes the calculation procedure and data considered in order to design the steel structure of the HEATER. 1.2

REFERENCE DOCUMENTS & DRAWINGS - Heater Assembly xx - Foundation Assembly / Details with loads

1.3

xx

CALCULATION CODES - Uniform Building Code Volume 2 - Minimum Design Loads for Buildings and other Structures - Manual of steel construction - Allowable Stress Design - Specification for Structural Steel Buildings AISC

1.4

UBC-97 UBC-97 AISC – ASD/01 360-05

MATERIAL AND CODE ALLOWABLE VALUES Material used for the structures : Yield stress fy: 235 Minimum Tensile stress fu: 400

JIS SS4002or equivalent N/mm (thickness ≤ 16 mm) N/mm2

2 2.1

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LOAD CALCULATION PRIMARY LOADS The decomposition of the loads into following primary loads : - Structure Self-Weight

(SLF):

- Extra Steelwork Weight

(EXTSTEEL):

- Platform

(EXTPLTF):

- Refractory Loads

(REFRACT):

- Pipe empty loads

(PPEMPT):

- Pipe Operating Loads

(PPOPER)

- Hydrostatic test loads

(PPTEST)

- Burners - Air Duct

(BURN): (ADUCT):

- Live Load 1

(LL1):

- Wind Load +X - Wind Load +Y - Earthquake Load +X - Earthquake Load +Y

WLX WLY EQX EQY

- Thermal Load

TMP

Weighs of the structural components automatically calculated by the program, and based on the model feature. Extra Steelwork weights not directly included in the model and not automatically calculated. Platform Extra Steelwork weights not directly included in the model and not automatically calculated. Weights of the refractory lining surfaces applied to the structural elements. Weights of all the operating pipes installed on the structure considered empty. Weights of the pipes filled with gas or liquid fluid as they are during the normal operation of the plant and load at terminal points. Weights of the pipes considered full of water as they are during the hydrostatic test conditions Weights of the burners applied to the radiant floor Weights of air duct installed on heater For the calculation of the foundation loads and structural analysis has been considered an overload of 500 Kg/m2 on each platforms. According to UBC-97 According to UBC-97 According to UBC-97 According to UBC-97 A thermal load has been considered on steel structures during normal operation according to spec n° 00-ZA-E205001-rev.02 Tmax on frame = 47°C Tmin on frame = 2°C Tmax on furnace skin = 83°C Tmin on furnace skin = 38°C

2.2 2.2.1

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LOADING DETAILS Radiant cell

2.2.1.1 Radiant Floor A.1

FLOOR

External Radius Internal Radius support internal Radius External Diameter Internal surface diameter support internal diameter Floor thickness Overall Surface Floor surface weight burners supporting surface External surface Refractory (wet) Wet D.ty M.W.C. 1:2:4 Thickness 75 Wet D.ty VLWC 1:0:5 Thickness 125 A 1.2 Burners Weight of each burner considered number of burners Overall

burners weight

A 1.3 Steelwork Extra steelwork not modelled Extra steelwork weight

2474 mm 1697 mm 515 mm 4948 mm 3394 mm 1060 mm 6 mm 2 19,2 m 905,7 Kg 8,16 11,1

9,06 KN

2

m 2 m

57,04KN 3 1930 Kg/m mm 3 1215 Kg/m mm

450 6

Kg

2700 Kg 27,00KN

40,00 Kg/m 769,15 Kg

2

7,69 KN

Input Sap Data

Overall refractory weight distribuited on surface Overall steelwork weight distribuited on surface Overall burners weight distributed on surface

Overall floor weight

100,79

KN

Internal surface

External surface

load case

2,97 0,4

REFRACT EXTSTEEL BURN

KN/m2 KN/m2 2,97 0,4 3,31

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2.2.1.2 Radiant Lateral walls LATERAL WALL External Diameter Height 9198,0 Thickness 5,0 Lateral Surface Lateral surface weight Refractory (wet) L.W.C. 124 Thickness 75 V.L.W.C 105 Thickness 100 Steelwork Extra steelwork not modelled Extra steelwork weight

4948

142,9 5609,1

1400 1215

mm mm mm 2 m Kg

56,1

KN

323,7

KN

Kg/m3 mm Kg/m3 mm

20,00 Kg 2858,1

Kg/m2 28,6 tot. weight

Overall refractory weight distribuited on surface Overall steelwork weight distribuited on surface

KN 408,4

KN

load case KN/m2 2,26 REFRACT EXTSTEEL 0,20

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2.2.1.3 Heater Arch ARCH Diameter 4948 Thickness 6 Surface 19,2 Arch surface weight Rectangular hole Lenght 4900 Width 1453 hole surface Arch surface without hole

905,7

mm mm m2 Kg

7,1

mm mm m2

12,11

m2

Refractory (wet) L.W.C. 124 Thickness 75 V.L.W.C 105 Thickness 125 Steelwork Extra steelwork not modelled Extra steelwork weight

1400 1215

20,00 242,2

KN

31,105

KN

Kg/m3 mm Kg/m3 mm

Kg Kg/m2 2,4 tot. weight

Overall refractory weight added to arch surface Overall steelwork weight added to arch surface

9,1

2,57 0,20

KN 42,6 KN/m2 KN/m2

KN REFRACT EXTSTEEL

2.2.2

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Radiant Internal coil

Type of fuel

Fuel Oil

Bare tubes O.D: Bare tubes thickness Bare tubes I.D. Maximum Operating fluid density Water density for hydrostatic test Pipe weight per meter Operating fluid weight per meter on each pipe Water weight per meter inside each pipe Number of tubes on each anchor Medium pipe lenght Return bends medium diameter Number of return bends on each anchor Bends unit weight Operating fluid on each return bend Water weight on each return bend

141,3 mm 6,55 mm 128,2 mm 556 Kg/m3 1000 Kg/m3 21,77 Kg/m 7,18 Kg/m 12,91 Kg/m 2,0 7,800 m 254,0 mm 2,0 8,7 Kg/each 2,9 Kg/each 5,1 Kg/each

Pipe empty weight on each anchor (2 tube + 2 bend) Pipe weight with operating fluid on each anchor (2 tube + 2 bend) Pipe full weight on each anchor (2 tube + 2 bend)

356,9 Kg 474,6 Kg 568,6 Kg

Crossing Tubes Number of crossing tubes Medium pipe lenght Empty crossing tubes weight Operating crossing tube weight (pipes + Op. fluid) Test crossing tube weight (pipes + water)

4,0 2,248 m 195,7 Kg 260,3 Kg 311,8 Kg

Anchor number Total number of tubes on each anchor Total number of bends on each anchor

24,0 48,0 48,0

Overall empty weight Overall operating weight (Pipe + Operating fluid) Overall test weight (Pipe + water)

8761,6 Kg 11650,5 Kg 116,5 13957,4 Kg 139,6

Point empty weight applied on each anchor (ELEV. 19050) Point operating weight applied on each anchor (ELEV. 19050) Point test weight applied on each anchor (ELEV. 19050)

87,6

KN KN KN

3,65 4,85 5,82

KN KN KN

PPEMPT PPOPER PPTEST

2.2.3

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Convection cell

2.2.3.1 Convection Lateral vertical walls Width 4900,0 Height 3555,0 Thickness 5,0 Surface 17,4 Weight of each convection wall Refractory (wet) D.ty LWC 1:2:4 Thickness 150 Steelwork not modelled Extra steelwork not modelled Extra steelwork weight

683,7

mm mm mm m2 Kg

1400

Kg/m3 mm

20,00 348,4

Kg/m2 Kg 3,5

Overall convection wall weight (2X) Overall refractory weight distributed each surface Overall steelwork weight added to each surface

6,8

KN

36,6

KN

KN 93,8

KN

2,10 0,20

KN/m2 KN/m2

REFRACT EXTSTEEL

2.2.3.2 Convection End tube sheets (E.T.S.) width 1453,0 Height 3555,0 Thickness 13,0 Surface 5,2 Weight of each convection wall Refractory (wet) Wet D.ty LWC Thickness 100

Steelwork not modelled Unit Weight

527,1

1400

mm mm mm m2 Kg

5,3

KN

7,2

KN

1,0

KN

13,5 27,1

KN KN

Kg/m3 mm

20 Kg/m2 tot. weight of each End Tube Sheet Overall End Tube Sheet weight

Overall refractory weight added to each E.T.S. surface

1,40

KN/m2 REFRACT

Overall steelwork weight added each E.T.S. surface

0,20

KN/m2 EXTSTEEL

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2.2.3.3 Convection Header Boxes Deep considered for the Header boxes Width 2353,0 Height 4455,0 Surface 10,5 Steelwork not modelled sheet thickness Plate steelwork weight Refractory (wet) D.ty LWC 1:2:4 Thickness 50 Extra Steelwork not modelled Unit Weight

450

mm mm mm m2

5,0 411,4

mm Kg

1400

Kg/m3 mm

50 Kg/m2 tot. weight of each Header Box Overall Header Boxes weight

Overall refractory weight distributed on each E.T.S. surf. Overall steelwork weight distributed on each E.T.S. surf.

4,1

KN

7,3

KN

5,24

KN

16,7 33,4

KN KN

1,42 1,81

KN/m2 REFRACT KN/m2 EXTSTEEL

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2.2.3.4 Convection Piping (coil, inlet &outlet piping) CONVECTIVE PROCESS COIL type of fuel Operating fluid density Water density for Hydrostatic test

fuel oil 556 1000

Bare tube external diameter Bare tube thickness Bare tube internal diameter Bare tube length Nr of flow passes Number of tubes N° tubes/row Number of rows

141,3 6,55 128,2 5,226 4 44 4 11

Number of 180° return bends Medum diameter of 180° return bends

40 254

single empty tube weight per meter Operating fluid weight per meter inside each tube Water weight per meter inside each pipe

21,76 Kg/m 7,17 Kg/m 12,90 Kg/m

Weight of each empty bend Operating fluid weight per meter inside each bend Water weight per meter inside each bend curve

8,68 Kg/each 2,86 Kg/each 5,14 Kg/each

Overall empty coil weight (pipes + bends) Overall Operating coil weight (pipes + bends + operating fluid) Overall Test coil weight (pipes + bends + water)

5350

Kg/m3 Kg/m3 mm mm mm m

mm

Kg

53,50

KN

85,22

KN

98,26 115,90 129,98

KN KN KN

7113 Kg 71,13 KN 8522

Kg

STUDDED SURFACE AROUND CONVECTIVE COIL 25,40 mm Stud height Studs diameter 12,70 mm studs per meter 1260 stud /m Number of bare tubes not finned Number of studded tubes 28 5,026 m studded surface length (on each tube) 0,001013 m2 exposed surface of each stud studded exposed surface of each tube 6,414 m2 total exposed surface calculated (studs+ tubes) 242,04 m2 4476,4 Kg 44,76 Weight of studded surface Overall empty coil weight Overall Operating coil weight (tube + Op. fluid) Overall test coil weight (tube + water)

9826 11590 12998

Kg Kg Kg

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Height of End Tube Sheet portion Width of End Tube Sheet portion Heading surface with coil weight distributed

3555,0 1453,0 5,17

Overall empty tube weight distributed on each convection header surfaces Overall Operating weight distributed on each convection header surfaces (tube + Op. Fluid) Overall test weight distributed on each convection header surfaces (tube + water)

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mm mm m2

9,51 KN/m2

PPEMPT

11,22 KN/m2

PPOPER

12,58 KN/m2

PPTEST

2.2.3.5 Inlet & Outlet terminal points load TAG F xF yF N N N Nm Nm Nm N1 9342 17346 17346 7566 5694 5694 N2 9342 17346 17346 7566 5694 5694

2.2.4

z

M

x

M

y

M

z

Breeching

C.1 BREECHING Base lenght 4900 mm Base width 1453 mm plate thickness 5 mm Overall SAP surface 10,2 m2

C.1.1 Refractory (wet) Wet D.ty LWC 1:2:4 Thickness 75 Overall breeching refractory weight

1400 1071

Kg/m3 mm Kg

10,71

KN

C.1.4 Steelwork not modelled Steelwork not modelled 30Kg/m2 Overall steelwork not modelled weight 306Kg

3,06 KN

tot. Breeching Weight 13,77 KN

Overall breeching refractory weight distributed on modelled surface1,05 Overall breeching steelwork weight distributed on modelled surface0,30

KN/m2 REFRACT KN/m2 EXTSTEEL

2.2.5

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Platforms, Vertical ladders & Stairs Live load (for base foundation loads )

500

Kg/m

2

2

Grating 37 Structure 75 Handrail 16 Toe board

7

Total 135

Kg/m 2 Kg/m 2 Kg/m 2 Kg/m Kg/m

2

2.2.5.1 Platforms EL+ 3000 on plinth L

Dimension

LengthWidth mm mm 1250 1835

Plant platform at 0°

Surface m2 2,29 nr.supporting beam

load on middle beam KN/m

Total platform Dead load

309,66 Kg

3,10

KN 2

0,84

Total platform Live load

1146,88

11,47

KN 2

3,13

2.2.5.2 Platforms EL+ 3000 Internal Radius

Dimension

mm 2474

Plant

Middle radius modelled mm 3104

External Radius

Angle (°)

mm 3854

360 nr.supp. beam

Total platform Dead load

3701,77

Total platform Live load

13710,24

Kg Kg

37,02

KN 2

137,10

KN 2

Surface m2 27,42 load on load on middle external beam beam KN/m KN/m 0,95 0,76 3,52 2,83

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2.2.5.3 Platforms EL+9000

Dimension

Plant

Internal Radius mm 2474

Middle radius modelled mm 2875

External Radius mm 3854

Angle (°)

Surface

345

m2 27,42

nr.supporting beam Total platform Dead load

3701,77 Kg

load on load on middle external beam beam KN/m KN/m

37,02

KN 2

1,07 0,80

137,10

KN 2

3,96 2,96

Kg Total platform Live load

13710,24

Dimension

Plant platform at 270° and 90°

Surface m2 5,79

Total length of beam modelled m 15,07 load on beams KN/m

Total platform Dead load

781,38 Kg

7,81

KN

0,52

Total platform Live load

2894,00

28,94

KN

1,92

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2.2.5.4 Platforms EL+12498 Dimension

Length mm 4000 6151 4000 6151

Plant platform at 0° Plant platform at 90° Plant platform at 180° Plant platform at 270°

Width mm 1124 1145 1124 1145

Surface m2 4,50 7,04 4,50 7,04

Dead Load on Plant platform at 0° Dead Load on Plant platform at 90° Dead Load on Plant platform at 180° Dead Load on Plant platform at 270°

606,96 950,79 606,96 950,79

Kg Kg Kg Kg

6,07 9,51 6,07 9,51

KN 1 KN 1 KN 1 KN 1

Load on each supp. beam column KN 0,76 0,77 0,76 0,77

Live load on Plant platform at 0° Live load on Plant platform at 90° Live load on Plant platform at 180° Live load on Plant platform at 270°

2248,00 3521,45 2248,00 3521,45

Kg Kg Kg Kg

22,48 35,21 22,48 35,21

KN 1 KN 1 KN 1 KN 1

2,81 2,86 2,81 2,86

Nr of portion consid.

2.2.5.5 Platforms EL+17203 Dimension Length mm Plant platform at 0° Plant platform at 90° Plant platform at 180° Plant platform at 270°

5133 1453 5133 1453

Width mm 1375 1349 1375 1349

Surface m2 7,06 1,96 7,06 1,96

Nr of portion consid. Dead Load on Plant platform at 0° Dead Load on Plant platform at 90° Dead Load on Plant platform at 180° Dead Load on Plant platform at 270°

952,81 264,61 952,81 264,61

Kg Kg Kg Kg

9,53 2,65 9,53 2,65

KN 1 KN 1 KN 1 KN 1

Load on each supporting beam column KN 0,93 0,91 0,93 0,91

Live load on Plant platform at 0° Live load on Plant platform at 90° Live load on Plant platform at 180° Live load on Plant platform at 270°

3528,94 980,05 3528,94 980,05

Kg Kg Kg Kg

35,29 9,80 35,29 9,80

KN 1 KN 1 KN 1 KN 1

3,44 3,37 3,44 3,37

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2.2.5.6 Vertical ladder and stairs E.1.8

Vertical ladder load (steelwork + live load)

Kg/m

Applicable to elev.

lenght (m)

weight (Kg)

3000 3000 11500 20000 25010

6,00 6,00 3,50 3,50 4,71

480 480 279,84 279,84 376,4

Applicable to elev.

lenght (m)

weight (Kg)

3000

5,25

1573,5

weight (KN)

80 LD.2 LD.2A LD.3 LD.4 LD.5 E.1.8

Stairs load (steelwork + live load)

Kg/m

4,80 KN 4,80 KN 2,80 KN 2,80 KN 3,76 KN

weight (KN)

300 SG.1

7,87 KN

2.2.6

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Wind Loads (WL)

WIND LOAD according toUBC-97 P = Ce*Cq*qs*Iw EXPOSURE Pressure coefficient on cilindrical surfaces Cq = Site elevation

D 0,8 19-25 m

Basic wind speed V =

44,4

wind stagnation pressure suggested for site elevation qs = Importance factor Iw =

m/s

According to spec. Nr. 00-ZA-E205001 rev.2 According to spec. Nr. 00-ZA-E205001 rev.2

1,30E-03 Mpa 1,15

1,30 KN/m2

(hazardous facilities)

2.2.6.1 Wind Load in X direction From To Elev. Elev. mm Radiant 3000 Radiant 7000 convection 12198 Stack I 17203 Stack II 27203 Stack III 37203

mm 7000 12198 17203 27203 37203 47203

Frontal dimension

Surface considered

mm 4948 19,8 4948 25,7 4900 24,5 1574 15,7 1570 15,7 1566 15,7

Ce

Specific Pressure on portion p(z)

2

1,48 1,62 1,71 1,83 1,93 2 2,39 37,5

Wind Load

kN/m2 KN 1,77 35,0 1,94 49,8 2,05 50,2 2,19 34,4 2,31 36,2

Total Wind X 243,18 KN INPUT SAP DATA Intermediate Portion columns Radiant 1 Radiant 1 Convection 2 Stack I 0 Stack II 0 Stack III 0

UNIT KN/m KN/m KN/m KN/m KN/m KN/m

wind load distributed 4,38 2,19 4,79 2,40 3,34 1,67 3,44 3,62 3,75

wind load distributed ext. Columns

load case WX WX WX WX WX WX

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2.2.6.2 Wind Load in Y direction WIND IN Y DIRECTION From Elev. To Elev. mm mm 3000 7000 7000 12198 12198 17203 17203 27203 27203 37203 37203 47203

Frontal dimension

Surface considered

m m2 4948 19,8 4948 25,7 1453 7,3 1574 15,7 1570 15,7 1566 15,7

Ce

Specific Pressure on stack p(z)

1,48 1,62 1,71 1,83 1,93 2 2,39 37,5 Total Wind Y Weight

Wind Load

kN/m2 KN 1,77 35,0 1,94 49,8 2,05 14,9 2,19 34,4 2,31 36,2

207,89 KN

INPUT SAP DATA Portion Radiant Radiant Convection Stack I Stack II Stack III

Intermediate columns

UNIT

2 2 1 0 0 0

KN/m KN/m KN/m KN/m KN/m KN/m

wind load distributed 2,92 1,46 3,20 1,60 1,49 3,44 3,62 3,75

wind load distributed ext. Columns

load case WY WY WY WY WY WY

2.2.7

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Earthquake Loads calculation (EQX/Y)

Earthquake load according to UBC-97 Sismic Zone Seismic zone factor Z Solid Profile Ca 0,40 Cv 0,56 I 1,25 R 4,5

4 0,4 SC

(*)

Notes According to spec. nr. 00-ZA-E-205001 rev.02 According to table 16-I of UBC-97 According to customer data According to table 16-Q of UBC-97 and for customer request According to table 16-R of UBC-97 and for customer request According to table 16-K “Hazardous facilities for toxic and explosives material” According to table 16-N of UBC-97 “Moment Resisting Frame systems – OMRF – Steel”

(*)

Note: In order to calculate the earthquake effect on the structure, the previous data have been assigned as input data to the model in SAP 2000 program and the effect of the earthquake as base reaction, structure elements deformation and vertical distribution of the lateral forces have been calculated automatically. According to UBC- 97 the automatic calculation of the elastic fundamental period of vibration (performed by SAP 2000) is based on following formulation based on method A: 3/4 T = C t * (hn ) = 0,802 s

where: Ct = 0,0853 is the coefficient for the calculation of steel moment-resisting frames hn = is the height of the structure above the base (m) from this value of T it is automatically calculated the total design base shear according to: C *I* V = v W R* T where W is the total weight of the structure.

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According to UBC 97, the base shear so calculated has to respect the following limits: 2.5 * Ca * I The value of base shear shall not exceed the value VMAX = *W R The value of base shear shall not be less than VMIN = 0.11* Ca * I * W 0,8* ZNv * I For seismic zone 4 the value of base shear shall also not be less than VMIN−Z4 = *W R Following are listed the values calculated for the heater in the different condition of work:

Work condition

Erection Operating Test Operating + 33% Live

Total Total base weight shear Vtot considered KN KN KN KN KN 1680 326 467 92.4 149.3 1748 341 485.6 96.16 155.4 1772 344 492.2 97.5 157.5 1937 379 538 106.5 172.2

VMAX

VMIN V

MIN-Z4

2.2.8

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Stack

2.2.8.1 Loading details Stack – sections JIS SS400 Stack Material 30000 mm Stack total Length Internal Stack Diameter 1550 mm Internal lining diameter 1450 mm

Stack portion I Casing and Refractory Height 10000 External diameter Shell thickness Lateral External surface Casing Weight

mm 1574 mm 12 mm 49,42 m2 4620,2 Kg

46,20 KN

Refractory LWC Refractory D.ty Thickness 50 Overall refractory weight

1400 Kg/m3 mm 3406,9 Kg

34,1 KN

20 Kg/m2 988,5 Kg

9,9 KN

Extra steel-work not modelled Safety margin Unit Weight Overall Extra Steelwork Weight Base skirt / flange weight Total base skirt weight

885,25 Kg

Intermediate stiffening rings weight Number of A-75x75x9 stiffening rings on portion 4 A-75x75x9 weight per meter 9,96 Kg/m Total A-75x75x9 stiffening rings weight 196,90 Kg

Overall Stack portion weight Overall Steelwork weight distributed along stack span Overall refractory weight distributed along portion span Point skirt weight at stack base

8,85 KN

1,97 KN

100,98 1,19 3,41 8,85

KN KN/m KN/m KN

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Stack portion II Casing and Refractory Height 10000 External diameter Shell thickness Lateral External surface Casing Weight

mm 1570 mm 10 mm 49,30 m2 3845,2 Kg

38,45 KN

Refractory LWC Refractory D.ty Thickness 50 Overall refractory weight

1400 Kg/m3 mm 3406,9 Kg

34,1 KN

20 Kg/m2 986,0 Kg

9,9 KN

Extra steel-work not modelled Safety margin Unit Weight Overall Extra Steelwork Weight Base skirt / flange weight Total base skirt weight

447,05 Kg

Intermediate stiffening rings weight Number of A-75x75x9 stiffening rings on portion 4 A-75x75x9 weight per meter 9,96 Kg/m Total A-75x75x9 stiffening rings weight 196,40 Kg

Overall Stack portion weight Overall Steelwork weight distributed along stack span Overall refractory weight distributed along portion span Point skirt weight at stack base

4,47 KN

1,96 KN

88,82 1,18 3,41 4,47

KN KN/m KN/m KN

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Stack portion III Casing and Refractory Height 10000 External diameter Shell thickness Lateral External surface Casing Weight

mm 1566 mm 8 mm 49,17 m2 3072,3 Kg

30,72 KN

Refractory LWC Refractory D.ty Thickness 50 Overall refractory weight

1400 Kg/m3 mm 3406,9 Kg

34,1 KN

20 Kg/m2 983,4 Kg

9,8 KN

Extra steel-work not modelled Safety margin Unit Weight Overall Extra Steelwork Weight Base skirt / flange weight Total base skirt weight Fan duct weight Overall Fan duct supporting stiffness weight Overall fan duct steelwork weight Overall refractory weight

443,59 Kg

4,44 KN

0,00 Kg Kg Kg

0,00 KN KN KN

Intermediate stiffening rings weight Number of A-75x75x10 stiffening rings on portion 4 A-75x75x10 weight per meter 9,96 Kg/m Total A-75x75x10 stiffening rings weight 195,90 Kg

Overall Stack portion weight Overall Steelwork weight distributed along stack span Overall refractory weight distributed along portion span Point skirt weight at stack base

1,96 KN

81,02 1,18 3,41 4,44

KN KN/m KN/m KN

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2.2.8.2 STACK VERIFICATION Stack stress verification are performed in according to API STANDARD 560.

Portion

From Elev.

To Elev.

I 17200 II 27200 III 37200

Stack general dimensions Refractory Shell Shell Outer internal thickness diameter diameter mm mm mm

Internal stack diameter mm

27200 1550 1450 12 1574 10000 A-75x75x9 4 37200 1550 1450 10 1570 10000 A-75x75x9 4 47200 1550 1450 8

1566

Portion height

Stiffness ring profile type

Nr. Of stiffness on span

A-75x75x10

4

mm

10000

Base & connecting flanges dimensions Rectangular stiffness Portion

I II III

Internal Plate diameter

External plate diameter

mm

mm

Lower plate thickness

Upper plate thickness

mm mm 2074 30 25 28 12 270 28 12 270 1890 30 30 1886 30 30

1574 1570 1566

Nr. Of stiffness on plate

Stiffness Height of thickness stiffness mm

Triangular stiffness Nr. Of stiffness on plate

mm

mm

0 0

Stiffness Height of thickness stiffness

30 28

8 8

mm 250 250

Bolts Dimensions Flanges at base of Portion Bolts nominal diameter Bolts number Bolt circle diameter M I 30 II 27 III 24

mm 36 30 28

2060 1662 1662

LOADS ANALYSIS AND STANDARD REFERENCE Wind action Checks are performed according to API 560 – Specification for steel chimneys According to the values of wind load calculated on paragraph 0 following are calculated the value of loads and moments at the base of each section of the stack Wind Load Shear Load Moment at uniformly at portion portion Portion Thk. distributed barycentre barycentre along height mm mm mm mm KN/m KN KNm KNm KNm I 12 1574 10000 46,2 3,48 34,83 174,16 108,80 1660,07 II 10 1570 10000 38,5 3,63 36,33 181,63 73,97 746,24 30,7 3,76 37,64 188,20 37,64 188,20 III 8 1566 10000 Diameter Portion Portion at portion casing height Base weight

Resulting Resulting Shear at moment at portion portion base base

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According to what written in the previous paragraphs, the stack here described has the following characteristics:

Portion Thickness

Corroded Thickness

mm mm I 12 10 II 10 8 III 8 6

Conical / cilindrical Top External Diameter

Portion Length

mm 1574 1570 1566

Lateral Surface

mm m² Kg 10000 49,4 4620,2 10000 49,3 3845,2 10000 49,2 3072,3 Total 30000 147,9 11537,7

Lining thickness = 50 mm

Specific weight = 1400 daN/m3

Refractory weight calculation Portion Refractory Density Portion lenght with refractory Refractory Thickness Refractory Weight Kg/m³ mm I 1400,0 10000,0 50,0 3406,9 II 1400,0 10000,0 50,0 3406,9 III 1400,0 10000,0 50,0 3406,9

mm

Kg

Casing Weight

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Max. Height of stack: 30 m The values above listed do not consider the effect of the corrosion on the stack walls. The corrosion on the walls it will be considered later. Material considered for Stack: Overall Stack Height considered = Young modulus E = Yield stress for the material fy = Lining Thickness = Lining density =

JIS SS400 30 m 200000 N/mm² 235 N/mm² 50 mm 1400 Kg/m³

Overall casing lateral surface Overall Casing weight Overall lining weight Overall extra weight for Equipments appended: Overall extra steelwork, stiffening and flanges weight

147,9 m² 115,38 KN 102,21 KN 0 KN 53,23 KN

Total platform surface considered Overall structural platform weight Live load considered on each platform surface Overall non permanent live load

0 m² 0 KN 2 KN/m² 0 KN

Overall ladder length Overall ladder weight

0m 0 KN

Overall stack permanent weight Overall weight with 33% of live load

270,82 KN 270,82 KN

Maximum resulting shear at stack base Maximum resulting moment at stack base

108,8 KN 1660,08 KMn

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ANCHOR BOLTS AND GROUND RING

The design procedure described in this paragraph is written according to chapter 10 of the book : “Process Equipment Design” Written by: L.E. Brownell and E.H. Young Publisher: Wiley Publishing Bearing plate thickness assumed t4 = Compression plate thickness assumed t5 = Gusset plate thickness assumed t6 = Base plate outer diameter De = Base plate bolt circle diameter Db = Base plate inner diameter Di = Minimum vertical load on base plate Nmin = Maximum vertical load on base plate Nmin = Maximum shear load at stack base Vmax = Maximum resulting moment at stack base Mmax = Number of bolts on base plate nb = Nominal diameter of anchor bolts db = Resistance section of anchor bolts Ares = Safety coefficient on yield stress n= Admissible stress for parts resistance check σadm = Max load on anchor bolts is given by: Nb =(-Nmin/nb)+(4Mmax/Nb*Db) =

30 mm 25 mm 12 mm 2074 mm 2060 mm 1574 mm 270,82 KN 270,82 KN 108,8 KN 1660,08 KNm 36 30 mm 561 mm² 1,5 156,67 N/mm²

82,02 KN

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Bearing plate design procedure: Stress on net section of anchor bolt: σb = Nb/Ab = 14,62 KN/cm2

VERIFIED

Maximum compression stress σc = Nmax/(3,14*Db*c) + 4*Mmax/(3,14*Db2*c) =

0,22 KN/cm2

where: c: Ring outer radius - medium shell radius = 1037 - 781 = 256 mm Base plate is defined as follows: distance between stiffening bmin = distance between stiffening bmax = external width of base plate l = ratio (l/ b)max =

150 mm 300 mm 250 mm 0,834 mm

thickness of bearing plate tb = (6*Mmax/σadm)0,5 = 29,6

mm

Where Mmax is calculated with the formulas: Mmax = c1*σb*b2 =

14,53 KNcm

Mmax = c2*σb*b2 =

22,82 KNcm

with c1 = 0,0765 by interpolation with c2 = -0,173 by interpolation

the value of “tb” has to be checked where the bolts are located In order to do this the maximum bolt load P is given by the formula: P = sb*Ab = 87,9 KN Where σb is the maximum stress admissible on bolts The Maximum bending moment supported by bolts is given by: Mmax = P*b/8 = 329,59 KN/cm The bearing plate thickness calculated with the considerations above is: tb=(6*Mmax/(lt-bhd)*σadm)0,5 =

24,2 mm

Where: lt : overall bearing plate width = 250 mm bhd :bolt hole diameter in bearing plate = 33 mm

THICKNESS t4 ASSUMED VERIFIED

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Compression plate design procedure: The thickness of the compression plate is calculated as follow: Mymax = (P/4*π)*[(1,3*ln(2*l/π*e)+(1-g1)] = Where: Mmax: P: lc : e: g1:

15,95 KNcm

Maximum bending moment acting on compression plate Maximum bolt load calculated above Radial distance from outside of skirt to outer edge of compression plate One-half distance across flats of bolting nuts = 23 mm Constant = 0,472 (by interpolation)

The thickness of the compression plate is: tc =(6*Mymax/sigma_amm)0,5 =

24,7 mm THICKNESS t5 ASSUMED VERIFIED

Vertical gussets plate design procedure: The vertical gusset plated equally spaced may be considered to react as a vertical column. From empirical calculations it comes that the minimum thickness required for the gusset plates is given by the equation: 18000*l*tg³-P*tg²-h²*P/1500=0 Where: l: h: t g: P:

is the width of the gussets (inches) is the height of the gussets (inches) is the thickness of the gussets (inches) is the Maximum value of bolt load calculated (lbs)

According to the values above listed the minimum thickness required for the gussets is: tg = 6,25 mm THICKNESS t6 ASSUMED VERIFIED

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INTERMEDIATE RING FLANGES STRESS CHECK Flange Stress Check The procedure considered for the stress check of the flanges is the following: The maximum pressure on flange due to vertical load is given by: P = P pmax −V = 2 2 ⋅ π D pe − D pi Af 4 The uniform load on middle flange diameter due to P mas-V is given by:

()

⎟D pe − D pi ⎟ ⎟ q p max −V = pmax −V ⋅⎟ ⎟ 2 ⎟ ⎟ ⎟ Assuming that the neutral axis for maximum moment passes from the section axis and assuming that the highest pressure value is located on bolt circle diameter, the maximum pressure on flange due to wind is given by: M M Max pmax −W = Max = 2 2 π D pe − D pi ⋅Dcb A f Dcb 2 Assuming that this pressure is uniformly distributed on compressed side of the flange it can be calculated the uniform load on middle flange diameter due to this pressure: ⎟D pe − D pi ⎟ ⎟ q p max −W = 2 ⋅pmax −W ⋅⎟ ⎟ 2 ⎟ ⎟ ⎟ Where: P: is the maximum vertical load calculated at the base of the section considered Mmax is the maximum moment calculated at the base of the section considered Dpe & Dpi are the Outside and the Inside flange diameters Dcb is the Bolt Circle diameter

()

the worst load combination is given in the position where the two loads add one to the other: qmax = q p max −V + q p max −W With the geometry assumed it follows that the distance between the stiffness on bolt circle diameter is given by: πD bmax = cb − t s Ns

where: ts Ns

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is the thickness of the stiffness is the total number of stiffness (assumed)

Now each flange can be assumed as a beam simply supported in the position where it joins to the stiffness, so the maximum moment calculated between the two supports is given by: 2 qmax ⋅bmax = Mf 8 The stress check of the flange is verified if

σMf = where: tf

Mf ≤ σadm− f 2 bmax ⋅t f 6 is the thickness of the flange (assumed)

In order to check the maximum stress of the stiffness placed on each flange they are calculated the maximum shear load and the maximum moment acting at the base of each stiffness. In order to do this, the flange is considered as a beam uniformly loaded and supported by each stiffness. From this consideration the maximum reaction and the maximum moment calculated under the stiffness are given by the equations: 1 1 2 Rmax − s = qmax bmax M max − s = qmax bmax 2 12 From these values it is easy to calculate the maximum shear and bending stresses: 6 τmax − s = Rmax σmax − s = M max 2 hs t s t s hs where: ts is the thickness of the stiffness (assumed) hs is the height of the stiffness (assumed) The stress of the stiffness is verified if 2 2 σid − s = σmax − s + 3τ max − s ≤ σ adm− f

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Following are listed all the geometric data and the resulting value calculated according to the procedure above described. Flange at base of Stack External portion DIA

Stack Shell Thk

Flange Outside Dia

Flange inside Dia

Flange circular surface

Flange thk

ts

Dpe

Dpi

Af

tf

II 1570

10

1890

1570

869152

30

III 1566

8

1886

1566

867142,4

30

Dext mm mm mm mm mm2 mm

Section Bolt Circle diameter Nr. of stiffness on interm. flange Stiffness Height Stiffness Thk Dcb Ns hs ts mm mm mm II 1662 30 250 8 III 1662 28 250 8 Uniform load Max moment at Max on middle section base due pressure on Section diameter due to wind or flange due to to vertical earthquake vertical load load PMax Mmax Pmax-V qpmax-V KN KNm N/mm2 N/mm II 169,84 746,24 0,20 31,26 0,52 82,66 113,92 III 81,02 188,20 0,09 14,95 0,13 20,89 35,84 Max Vertical load on flange

Max uniform load pressure on on middle flange due diameter due to wind to wind Pmax-W N/mm2

Max uniform load on flange

qpmax-W N/mm

qmax N/mm

Section distance between the stiffness Max Bending moment on flange Max stress on flange Check bmax mm II 189,46 0,51 17,99 III 203,06 0,18 6,07 Max reaction Max moment under stiffness under stiffness Rmax-s Mmax-s KN KNm II 26,98 0,29 3,45 13,49 23,62 OK III 9,10 0,10 1,25 4,55 7,98 OK

Section

Mf KNm

sMf N/mm2 OK OK

Max bending Max shear stress Max ideal stress Check stress on Stiffness on Stiffness on Stiffness smax-s tmax-s sid-s N/mm2 N/mm2 N/mm2

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Flange bolts stress check The flange bolts considered in the following procedures are in class 8.8 with the following values for admissible stress: σadm-b = 373 N/mm2 2 τ adm-b = 264 N/mm The procedure considered for the stress check of the flange bolts is the following: The maximum axial load on each bolt is given by the difference of the axial load due to bending moment at the base of each section and the minimum vertical load calculated in the same section. The maximum axial load on worst stressed bolt is given by: 4 M max N min − FN − b = nb Dcb nb From this follows that the highest axial stress on bolts is given by: σmax −b = FN − b Ares The maximum shear stress on each bolt is given by: τmax −b = Vmax Ares nb where: Nmin is the minimum vertical load calculated at the base of the section considered Vmax is the maximum shear load calculated at the base of the section considered is the maximum bending moment calculated at the base of the section Mmax considered Dcb is the bolt circle diameter nb is the total number of bolts considered on the flange Ares is the resistance section of the bolts considered The bolt are verified if 2 2 σid −b = σmax − b + 3τ max − b ≤ σ adm − b

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The data and the results of the procedure applied to each intermediate flange are following listed:

Section

Stack Ext. Dia.

Stack Shell thk.

Dext ts mm mm II 1570 10 30 1662 30 27 459 III 1566 8 28 1662 27 24 353

Section

Min Vertical load on flange

Max shear load due to wind or earthquake

Nr. of bolts on interm. flange

Bolt Bolt hole dia. Bolt Bolt resistance circle dia. on flange nominal Dia. section

Nb mm

Max moment at section base due to wind or earthquake

PMin VMax Mmax KN KN KNm II 169,8 74,0 746,2 54,2 118,1 5,4 118,5 III 81,0 37,6 188,2 13,3 37,6 3,8 38,2 OK

Db mm

db mm

M 0

Ares mm2

Max axial load on worst stressed bolt

Max axial stress on bolts

Max shear stress on bolts

Max ideal Check stress on bolts

FN-b KN

smax-b N/mm2

tmax-b N/mm2

sid-b N/mm2 OK

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CHECK OF CASING With reference to the stack structure section, considering that the ratio between diameter (D) and thickness (t) is very high, in the following they will be used simplified formulas:

A = π*D*t W = (π*D2*t)/4 I = (π*D3*t)/8 Specific data for resistance check (thickness of corrosion = 2 mm) External Wall thickness Portion A W corroded corroded diameter 3 mm mm cm² cm cm I 10 1570 493 19.359 II 8 1566 394 15.409 III 6 1562 294 11.497

I 4

1.519.703 1.206.494 897.954

Corroded casing weight KN 38,70 30,88 23,10

The overall structure stability value does not consider possible allowances due to fabrication, while the possible corrosion allowance value is deducted at checks of resistance. VERIFICATION Check on stability are performed in connection with admissible compression stresses, as per API 560 Par. 9.3. Admissible compression stress is the minimum value between: σadm-1 = 0,5*Fy = 11,75 N/mm² or σadm-2 = 0,56*E*t/(D*(1+(0,004*E/Fy))) With values defined as follows: t= is the corroded shell plate thickness (mm) D = is the outside stack diameter (mm) E = 200000 N/mm² is the Elastic Young Modulus Fy = 235 N/mm² :is the material minimum yield strength at design temperature

Following are listed the data considered in order to check the stress status of each shell section. The value of stress on each section is calculated with the vertical load coming from the weight calculation of each section considered with thickness corroded

Portion

From Elevation

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To Elevation

Max Vertical Load at portion base (N)

mm mm KN KNm I 17200 27200 271 1.660 9,124 16,20 II 27200 37200 170 746 5,275 12,99 III 37200 47200 81

Max Moment at portion base (Mmax)

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Stress Calculated at base portion

σadm-2

cm4

KN/cm2

188 1,912 9,77

DYNAMIC CHECK ON WIND EFFECT DYNAMIC CHECK Dynamic check is performed according to point 9.5 of API 560. Vc1 = 5*Dt*f Vc2 = 6*Vc1 Where: Dt = 1,562 m Diameter of stack top f = first mode frequency f = 0,5587*(E*I*g/W*H4)0,5 where: W = 46,33 lbs/in is the Weight per unit height of stack E = 29007548,8 psi is the Young Elastic Modulus g = 386 in/s2 is acceleration due to gravity I = 29023,3 inch4 is the medium moment of inertia H = 1181,1 in is the total stack height f = 1,061 Hz Vc1 = 5*Dt*f = 8,29 m/s Vc2 = 6*Vc1 = 49,71 m/s

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ACCEPTABLE WITH STRAKES ACCEPTABLE

XX

Check

VERIFIED VERIFIED VERIFIED

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STIFFENING RING PRESENCE CHECK Dynamic check is performed according to point 9.5.5 of API 560 Stiffening ring are required to prevent ovalling if: fr/2*fv

a : eccentricity 6

external to the kernel of inertia

this condition forces to the research of the position of the real neutral axis. The value of the position of the neutral axis is found by attempts with the following empirical equation: b 3 + bd 2 + x x nAf (d + h) x − nAf h(d + h) = 0 6 2 Where (ref. to picture 1): b is the plate dimension parallel to the moment axis x is the position of the neutral axis with respect to the base edge d is the position of perpendicular load with respect the plate edge n = 15 is the homogenization coefficient between elastic modulus Af = Ab*nb is the total area of the bolts strengthen h is the distance between the base edge and the axis of the anchor bolts strengthen Once that the value of “x” is calculated the value of the maximum sigma acting on the cement plinth is calculated with the formula: N *x

σc =

2

b

x − nAf (h − x) 2

The stress of the maximum compression on plinth is verified if : σc ≤ 0,44 * Rck where Rck is the cubic admissible resistance of the concrete considered. From the value of σc, it is calculated for proportion the value of the stress acting on the base plate in correspondence of the section column flanges or stiffness:

σc x

=

σs xs

⇒ σs =

σc x

xs

where (ref. to picture 1): σs is the value of sigma at stiffness level is the distance between stiffness and neutral axis xs = x- m1

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Base Plate stress calculation Once that the values of σc and σs have been calculated from one of the procedures above described the stress check of the base plate continues as follows for both the conditions: The base plate is now considered as a beam rigidly joined at level of stiffness and uniformly loaded by a load “q” calculated as follows: σ + σs q = m1* c 2 The maximum momentum given by this kind of restraint is: 2 2 q * l 2 − q * m2 = M Max 8 2 where l2 is the intermediate distance between the base plate stiffeners m2 is the distance between the flange of the column section and the plate edge The Maximum sigma acting on the flange is:

σp = M Max = W

M Max ⎟m1 * thk 2 ⎟ ⎟ ⎟ ⎟ 6 ⎟ ⎟ ⎟

Where: W is the resistance modulus of the section considered. thk is the thickness of the plate (assumed) Note: The procedures above described are referred to a moment with axis parallel to direction 2. In the case in which the moment considered is directed as axis 1 the related values of geometric dimensions as “a”, “b”, “l”, “m” etc have to be considered. In order to take into account the effect of both the moments acting at the base of the column, the procedures above described are performed considering one at time both the moments acting on the two main direction of the section. The value of stress so found it has to be lower than the admissible stress calculated as ratio between the yield stress of the material considered for the base plate and a safety coefficient. If the stress is verified the thickness assumed has not to be increased.

5.1.2

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Stress check on Base Plates A – B – C – D – E – F

Plinth

Comb.

Fn

F1

F2

M1

M2

F

CB7O

KN 950,4

KN 60,7

KN -15,1

KNm 5,8

KNm 25,4

Yield Stress of the material JIS SS400 = Admissible stress of the base plate material = Cement Plinth cubic resistance Rck = Admissible stress on cement plinth = Base Plate thickness assumed = Considered 8 bolts M30

235 N/mm² 235 / 1,5 = 156,67 N/mm² 21 N/mm² 21 * 0,44 = 9,24 N/mm² 35 mm

Action dominant

M1 M2

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Plate dimension parallel to Moment (b) mm 500 500

Plate dimension perpendicular to Moment (a)

Plinth section (Ac)

mm 500 500

mm² 250000 250000

Distance Distance Total of between Nr. of bolts resistance normal bolts Action strengthen section of force strengthen dominant on last row bolts from and plate (nb) strengthen edge edge (Af) (d) (h)

M1 M2

Action dominant

M1 M2

Action dominant

M1 M2

mm 0 0

mm 3 3

Compression Stress on Plinth (σc) N/mm² 0,28 1,22

mm² 1683 1683

Plinth stress check

Sigma-c CLS OK Sigma-c CLS OK

mm 425 425 Sigma on stiffeness for proportion (σf) N/mm² 2,37 2,12

Plinth Elastic modulus (Wc) mm³ 20833333 20833333

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Eccentricity (e)

eccentricity case

mm 6,12 26,71

Case 1: e