Post on 17-Mar-2020
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Drums
• Identify Differences Between Drums And Tanks
• Process Overview Of Drum Uses
• Mechanical Overview Of Drum Design
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Pressure VesselVs Tank
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• Designed To Contain Or Hold A Fluid• Capable Of Withstanding Internal Pressure At
Least 15 psi Above Atmospheric Pressure• Cylindrical Section With Shaped Ends• Fabricated of Metal Typically But Plastics Can Be
Used• Design and Construction Per Legal Code (ASME
Section VIII)• Protected From Overpressure By Pressure Relief
Device (Relief Valve or Rupture Disk)
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Design Criteria Pressure Vessel Tank
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Pressure
Temperature
Capacity(Cost per Unit Volume)
Design Standards
15 psig & Greater Less Than 15 psig
Limited BySelected Materials
Preferably 200 °F Maximum
Medium ToHigh
Low
ASME Division VIII API 650 (Up to 2.5 psig)API 620 (Up to 15 psig)
Pressure Safety API 2000API 520
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Process Overview
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AccumulationSurge
Storage
RefluxHoldingStorage
MixingHomogeneity
Suspension
ReactionStatic
Dynamic
Feed
DispersionDiffusion
Liquid - LiquidLiquid - Solid
Fixed BedPlug FlowFluid Bed
Stirred
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Separation
Chemical
Physical
Distillation(Boiling Points)
Stripping(Liquid To Gas Transfer)
Absorbing (Gas To Liquid Transfer)
Gas - Liquid
Light Liquid – Heavy Liquid
Gas - Solid
Liquid - Solid
Service Equipment Type
Accumulation Or Mixing Of Materials
Reaction Chamber For Chemical Change Of Materials
Separation By Chemical Means
Separation By Physical Means
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AccumulatorDrum
Reactor
ColumnTowerFilter
Separator
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VERTICAL HORIZONTAL
Columns
Vapor – Liquid Separators
Liquid – Liquid Separators
Vessels With Mechanical
Agitation
Pressurized Storage
Fixed Bed Reactors
Plug Flow Reactors
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Mechanical Overview
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VesselWallShell
Head
Head
Cent
er L
ine
ELEV
ATIO
N V
IEW
PLAN
VIE
W
• Inside Diameter (D) – Inside Diameter Of Vessel• Outside Diameter (OD) – Outside Diameter Of
Vessel (Inside Diameter Plus Twice Wall Thickness)
• Length (L) – Measured From Tangent Line Of Bottom Head To Tangent Line Of Top Head (Length of Shell)
• Wall Thickness (t) – Varies Based On Design Pressure
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ELEV
ATIO
N V
IEW
PLAN
VIE
W
Inside Diameter (D)
Inside Diameter (D)
Leng
th (L
)Wall
Thickness (th)
Wall Thickness
(tw)
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HEMISPHERICAL
ELLIPTICAL / DISHED
FLAT
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D
D = 2 * R
R
CL
T.L. = Tangent Line
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CL
AB
D
A = D/2
B = D/4
T.L. = Tangent Line
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T.L. = Tangent Line
CL
Rd
D
Rc
Rd = D Max.
Rc = 0.06 * Rd Min.
Rc
Pressure VesselDesign
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• Correct Size For Process Use
• Ability To Contain Fluid Under All Expected Operating Conditions
• Proper Selection And Design Of Internals / Attachments For Process And Operational Use
• Provide Necessary Interface With Surrounding Process And Facility
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PressureTemperature
Material SelectionCorrosion Allowance
DiameterLength
NozzlesSupports
Access
• Baffles To Aid Mixing Or Separation• Catalyst With Support Grids For Reaction• Cartridges or Media For Filtration• Piping To Aid Gas or Liquid Distribution / Collection• Trays or Packing To Aid Gas-Liquid Contact For
Absorption, Distillation, or Stripping• Ladder Rungs To Facilitate Access• Baffle / Tray Manways To Provide Personnel Paths
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Process• Agitators To Aid Mixing• Jackets For Heat TransferSupports• Skirt / Legs / Lugs• Insulation Clips / Rings• Pipe ClipsAccess• Ladders / Stairs• Platforms• Handrails
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• Process Connections
• Operational Connections
• Instrument Connections
• Maintenance Access
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INLET
OUTLET
VENT
DRAIN
LEVEL PRESSURE
TEMPERATURE
MANWAY
SeparatorDesign
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Continuous Phase: Vapor (Light)
Discontinuous Phase: Liquid (Heavy)
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Continuous Phase: Liquid (Heavy)
Discontinuous Phase: Liquid (Light)
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Continuous Phase: Vapor (Light)
Discontinuous Phase: Liquid (Heavy)
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Continuous Phase: Liquid (Light)
Discontinuous Phase: Liquid (Heavy)
• Select Correct Orientation For Process Purpose
• Determine Appropriate Sizing Method
• Calculate Vessel Dimensions To Achieve Target Separation
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Orientation Application Example
Vertical
Horizontal
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Liquid Droplet Separation From Vapor
Liquid – Liquid Separation (Light – Heavy Phases)
Compressor Suction Knockout Drum
Hydrocarbon – Water Separator
Fuel Gas Knockout Drum
Overhead Accumulator(Reflux Drum)
• Stokes (Vertical) - Rigorous
• Sauders-Brown (Vertical) - Simplified
• Disengagement Length (Horizontal)
• Residence Time (Horizontal)
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DIAMETER
LENGTH
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Ut2Ut1
Ut = Terminal Velocity
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Stokes Equation Sizing Coefficient
Particle Reynolds Number
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Figure 7-3, GPSA Engineering Data Book - 11th Ed.
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Design Two-Phase Separators Within The Right Limits – CEP 10-1993
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Without Mesh – No Mist Eliminator (Coalescing Pad)
With Mesh – Includes Mist Eliminator (Coalescing Pad)
Sauders-Brown Equation
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Service Multiply KsBy
Without Mist Eliminator(Or Use Rigorous Stokes Equation)
0.5
Amine Solution HandlingGlycol Solution Handling
0.6 to 0.8
Compressor Suction ScrubbersExpander Inlet Separators
0.7 to 0.8
Vapors Under Vacuum Ks = 0.20 Maximum
Wet Steam Ks = 0.25 Maximum
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Design Two-Phase Separators Within The Right Limits – CEP 10-1993
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Reference Particle Size (microns)
GPSA (General Separator Sizing) 150
API 521 (Flare Knockout Drum) 300to
600
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Dp
Ds = Separator Diameter
Ud
Ds
Utp
Ud = Design Vapor Velocity
Utp = Particle Terminal Velocity
Dp = Particle Diameter (Cut)
Ks = 0.07 to 0.35
• Identify Process Use Of Drums• Determine Mechanical Design Of Drum That Best Fits
Process Use– Safety– Environment– Cost Effectiveness
• Determine Key Elements Of Drum Design– Volume / Dimensions– Pressure / Temperature– Nozzles / Internals
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