pressure vessel design for hpgtpc •pressure vessel thickness calculations by a. design rule...

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  • Prashant Kumar, Vikas Teotia, Sanjay Malhotra

    Bhabha Atomic Research Centre Trombay, India

    Pressure Vessel Design for HPgTPC

  • Topics discussed in previous meeting on 31.5.19

    • Alloys of Al 5083

    • Pressure Vessel Thickness calculations by a. Design rule

    and b. design by analysis

    • Deflection and Stress calculation of Pressure Vessel with

    Hemispherical closure were presented

  • Outline of presentation

    • Pressure Vessel Shell thickness calculation

    • Design and Analysis for Torispherical Head

    • Design and Analysis for Elliptical Head

    • Comparison of Elliptical Heads based on ratio of Major to Minor axis

    • Analysis of Support for Pressure Vessel

    • Summary

    • Future Work

  • Pressure Vessel with Torispherical Closure

    40

  • Torispherical Head Design

    Stresses at Junction of Crown and Knuckle

    Stresses at Junction of Crown

    As > is Compressive

    Therefore, there will be localised

    stress and Buckling

    To minimise local stresses at junction:

    ASME Specifies

    1. Knuckle radius > = 6 % of Rc

    2. Crown radius < 0.8 to 0.9 of ID

    Reference: UG-32 of ASME Section VIII Div 1

  • Torispherical Head Design

    Deflection = 6.086 mm

    Stress = 143.482 MPa

    Crown Radius = 5152.5 mm

    Knuckle Radius = 343.5 mm

    Thickness of Head = 45 mm

    Yield Strength = 205 MPa

    Material = Equivalent to Al 5083

    Design Factor = 1.4

    Small Knuckle > Higher Localized stresses

  • Deflection = 5.074 mm

    Stress = 121.243 Mpa

    Yield Strength = 205 Mpa

    Thickness of Head = 45 mm

    Design Factor = 1.7

    Material = Equivalent to Al 5083

    Reduction of localized stresses at Knuckle / Cont.…

    R350

  • Stress Conc. at Junction of Flange & Knuckle end

    Deflection = 4.998 mm

    Stress = 85.955 Mpa

    Yield Strength = 205 Mpa

    Inner Rc = 5152.5 mm

    Inner Rk = 350 mm

    Design Factor = 2.4

  • At Crown

    At Equator

    Ellipsoidal Head Design

    Courtesy: Theory and Design of Pressure Vessels by John F. Harvey

  • Ellipsoidal Head Design

    a = 2862.5

    b = 2000

    a / b = 1.43

    Deflection = 3.43 mm

    Von-Mises Stress = 52.375 Mpa

    Yield Strength = 205 Mpa

    Material = Equivalent to Al 5083

    Design Factor = 3.9

    Thickness of Head = 40 mm

  • Deflection = 3.9 mm

    Stress = 59.66 Mpa

    Yield Strength = 205 Mpa

    Material = Equivalent to Al 5083

    Design Factor = 3.4

    a = 2862.5

    b = 2000

    a / b = 1.43

    Ellipsoidal Head Design / Cont...

    Thickness of Head = 35 mm

    For 0.7 – 1.5 Mpa Design Pressure

    Most Preferred

  • Deflection = 23.87 mm

    Stress = 259 Mpa

    Yield Strength = 205 Mpa

    Thickness of Head = 35 mm

    Material = Equivalent to Al

    5083

    a = 2862.5 mm

    b = 1431.25 mm

    a / b = 2

    a = 2862.5 mm

    b = 2000 mm

    a / b = 1.43

    Deflection = 3.9 mm

    Stress = 59.66 Mpa

    Yield Strength = 205 Mpa

    Thickness of Head = 35 mm

    Material = Equivalent to Al

    5083

    a = 2862.5 mm

    b = 954 mm

    a / b = 3

    Deflection = 9.5 mm

    Stress = 107.287 Mpa

    Yield Strength = 205 Mpa

    Thickness of Head = 35 mm

    Material = Equivalent to Al

    5083

    Comparison of Ellipsoidal Heads

  • Vessel Assembly with Ellipsoidal Head

    Maximum Von

    Mises Stress =

    62.226 Mpa

    Yield Strength

    = 205 MPa

    Maximum

    Deflection =

    4.234 mm

  • Ellipsoidal Head with Nozzle

    Without Nozzle Stress = 52.375 Mpa

    With Nozzle Stress = 95.792 Mpa

    Yield Strength = 205 Mpa

    Thickness of Head = 35 mm

    Material = Equivalent to Al 5083

    Design Factor = 2.1

    Deflection = 3.556 mm

    Remarks: Not Satisfying ASME Section VIII Div I Criteria

    Therefore, Reinforcement near the Nozzle Section required

  • Stress Conc. around circular hole in Cylindrical Shell

    2.5 σ

    1.006 σ

    r = 3a

    r = a

    How Far to reinforce ?

  • Nozzle Reinforcement Analysis

    Maximum Von Mises Stress = 55.386 Mpa

    Yield Strength = 205 Mpa

    Design Factor = 3.7

    • Shell is weakened around nozzles, and must

    also support eccentric loads from pipes

    • Principle of Area Compensation

    • Usually weld reinforcing pads to thicken the

    shell near the nozzle. Area of reinforcement

    = or > area of nozzle

    600 mm

    600 mm

    Deflection = 2.9 mm

    Up to 2r from the

    center

    0.25r along the

    nozzle

  • Deflection = 0.508 mm

    Maximum Von-Mises Stress = 20.709 Mpa

    Yield Strength = 205 MPa

    Material = Equivalent to Al 5083

    Design Factor = 9.9

    Saddle Support Analysis

    Conclusion: Over-conservative

    Saddle Contact Angle = 120 Degree

    Approximate Weight of Vessel

    including Heads = 22 Ton

    Total Weight of Support = 675 Kg

  • Deflection = 8.8 mm

    Maximum Von-Mises Stress = 38.479 Mpa

    Yield Strength = 205 MPa

    Thickness of Head = 35 mm

    Material = Equivalent to Al 5083

    Design Factor = 5.3

    Saddle Support Optimization Analysis

    Saddle Contact Angle = 120 Degree

    Approximate Weight of Vessel

    including Heads = 22 Ton

    Total Weight of Support = 470 Kg

  • Saddle Support Optimization Analysis

    Deflection = 1.69 mm

    Maximum Von-Mises Stress = 17.033 Mpa

    Yield Strength = 205 MPa

    Thickness of Head = 35 mm

    Material = Equivalent to Al 5083

    Design Factor = 12

    Saddle Contact Angle = 120 Degree

    Approximate Weight of Vessel

    including Heads = 22 Ton

    Total Weight of Support = 488 Kg

    187 Kg Materials is saved compared to previous Design

  • Deflection = 5.894 mm

    Maximum Von-Mises Stress = 59.587 Mpa

    Yield Strength = 206.8 MPa

    Material = AISI 304

    Design Factor = 3.4

    Saddle Contact Angle = 120 Degree

    Approximate Weight of Vessel

    including Heads = 22 Ton

    Total Weight of Support = 436 Kg

    Further 52 Kg Materials is saved compared to previous Design

    Support Optimization / Cont.…

  • Summary and Conclusion

    • Shell Thickness calculation done for Al 5083

    • Initial Torispherical Head Design were carried out

    • Initial Ellipsoidal Head Design were carried out

    • Analysis for Nozzle reinforcement done partially

    • Pressure Vessel Support System have been optimized

    Note: In all calculation Joint efficiency were considered 1

  • Future Work

    • Shell thickness calculation to be tried with other competing materials

    • Rigorous analysis for both Torispherical Head & Ellipsoidal Design

    to be carried out (Design by Rules & Design by Analysis)

    • Nozzle reinforcement to be detailed (Design by Rule in particular)

    • More configuration for Pressure Vessel Support System can be tried

    • Joint Efficiency to be considered as per ASME BPV Code in further

    calculation

  • Thank You

    For

    Your Kind Attention