Pressure Vessel Design for HPgTPC Prashant Kumar, Vikas Teotia, - - PowerPoint PPT Presentation

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