Flare KO Drum-3

June 16, 2011Piruz Nezami

1Overview

Introduction Definitions and Functions Design Parameters Sizing Bases and Equations API 521 Sample Calculation Spreadsheet

2Introduction

API 521 - ISO 23251 Definition:

Vessel in the effluent handling system designed to remove and store liquids.

Function of Flare Knockout Drum:

To separate liquid from gas and hold maximum amount of liquid relieved in an emergency. KO drum is typically located close to the flare stack upstream of any liquid seal.

Unit knockout drums:

For process units which possibly release large amount of liquid, it is desirable to have local KO drums inside the battery limit. This reduces the sizing requirements for the main flare knockout drum.

Knockout drum can be horizontal or vertical.

3Design Parameters

1. Liquid droplet size limited to 300 to 600 m to avoid burning liquid outside the flame envelope.

2. Maximum liquid hold up must be considered for vapor-liquid disengagement calculations.

3. In addition to liquid holdup, liquids that previously accumulated in the drum and not pumped out (slop) should be taken into account.

4. API 521 recommends a minimum of 20 to 30 minutes holdup time. Longer Holdup might be required if it takes longer to stop flow.

5. Maximum vapor release may not coincide with the maximum liquid release.

4Design Parameters

6. Typically the relief rates (not rated capacities) used for flare header, flare tip, and knockout drum design.

7. It is normally not necessary to size local knockout drums for efficient vapor-liquid separation at maximum flow rate.

8. The economics of the drum design can influence the choice between horizontal and vertical drums.

Horizontal drums are more suitable for large liquid capacity andhigh vapor flow. They have lower pressure drop than vertical drums.

Vertical drums are typically used when the liquid load is low orlimited plot space is available.

5Design Parameters

9. Nozzle Configurations:

a) Horizontal Drums: Vapor entering at one end and exiting at the top of the

opposite end.

Vapor entering at each end and exiting at the center.

Vapor entering at the center and exiting at each end of the drum.

b) Vertical Drums: Vapor entering radially and exiting at the top of the drum.

A baffle is required to direct the flow downward.

Vapor entering tangentially and exiting at the top of the drum.

6Knockout Drum Sizing

Sizing a knockout drum is a trial-and-error process.

1st step is to determine drum size for liquid separation.

Liquid particles separate:

When vapor velocity is sufficiently low to allow the liquid dropout to fall.

When the vapor residence time is equal or greater than the time required for the liquid particles to travel the available height at dropout velocity (liquid dropout time).

The vertical height is usually taken as the distance from the top of the drum to the maximum liquid level.

7Vapor Travel - Liquid Dropout

T V : Vapor Residence Time T D : Liquid Dropout TimeL N : KO Drum Nozzle to Nozzle Length H V : Vapor Space HeightV V : Vapor Velocity V D : Liquid Dropout Velocity

High Liquid Level

H V

Nozzle to Nozzle Distance, L N

H L

V

NV V

LT =

D

VD V

HT =

8Horizontal Knockout Drum Sizing

Liquid Dropout Velocity:

VD : Liquid Dropout Velocity

g : Gravitational Constant (9.8 m/s2, 32.2 ft/s2)D : Particle Diameter

L : Liquid Density at Operating Conditions

V : Vapor Density at Operating Conditions

C : Drag Coefficient

CDg

VV

VLD

)(15.1 =

9Horizontal Knockout Drum SizingDrag Coefficient:

Re : Reynolds Number

: Vapor Viscosity at Operating Conditions

Cte : Constant (0.13 x 108 in Metric and 0.95 x 108 in Imperial Units)

2

32

)()()()()((Re))(

VLV DCteC =

10

API 521 ISO 23251 Sample Calculation

Total Flow Rate: 200,000 lb/hrLiquid Density 31 lb/ft3

Vapor Density 0.18 lb/ft3

Pressure: 2 psigTemperature: 300 FVapor Viscosity: 0.01 cPThe liquid equilibrium results in 31,000 lb/hr of liquid and 169,000 lb/hr of vapor.In addition, 500 gallons of storage for miscellaneous drainings from the unit is desired.The maximum allowable droplet size is 300 m.

11


Actual Vapor Rate RV= 169,000 / (3,600 x 0.18) = 261 ft3/secDrag Coefficient x Re2 C x Re2= [ 0.95 x 108 x 0.18 x (0.000984)3 x (31 - 0.18) ] / (0.01)2 = 5,021Dropout Velocity UC= 1.15 * [ 32.2 X 0.000984 x (31 - 0.18) / (0.18 x 1.3) ]0.5 = 2.35 ft/sec

Slop Cross Sectional Area AS= 66.8 (ft3) / L (ft)Holdup Cross Sectional Area AH= (31,000 / 31) x (30/60) (ft3) / L (ft)Drum Cross Sectional Area AT= pi x D2 / 4Vapor Cross Sectional Area AV= AT - AS - AH

12


AH

AS

AV

HH

HS

HH

HT (D)

2])([81 DSinAS =

2])([81 DSinAA SH =+

13


Diameter Length Cross Sectional Area Vertical Height Dropout Vapor Minimum

D L AT AS AH AV HT (D) HS + HH HV Time, TD Vel, VV Length, Lft ft ft2 ft2 ft2 ft2 in in in sec ft/sec ft

1 8.0 19.0 50.27 3.52 26.32 20.43 96.0 55.0 41.0 1.45 12.76 18.5

2 7.5 20.5 44.18 3.26 24.39 16.53 90.0 54.0 36.0 1.28 15.78 20.2

3 7.0 22.5 38.48 2.97 22.22 13.29 84.0 52.3 31.7 1.13 19.62 22.1

4 6.5 25.0 33.18 2.67 20.00 10.51 78.0 50.0 28.0 0.98 24.82 24.3

Case No

14

API 521 Sample calculation

FLARE KNOCK OUT DRUM PROG NO: JE-103Client: JACOBS Prepared By: Date:

Project: API 521 SAMPLE CALCULATION - 1 Checked By: Job No: XXXXX-100 RSubject: FLARE KNOCK OUT DRUM Tag No: V-XXXX E

Calc No: XXX-XXXX-XXXXX-000 File No: XXX-XXXX-XXXXX-000 Sheet: 1 of 1 V1 DESCRIPTION UNIT VALUE UNITS OF MEASUREMENT2 Drum Temperature, t F 300.0 Temperature3 Drum Pressure, P psi-g 2.0 Pressure4 Estimated L/D Ratio, R E -- 2.44 Mass Flow Rate5 Mass Flow Rate, M V lb/hr 169,000 Liquid Volumetric Flow Rate6 Molecular Weight, MW V lb/lbmole Vapor Volumetric Flow Rate7 Compressibility Factor, Z V -- Density8 Density, V lb/ft 0.180 Dimension9 Viscosity, V cP 0.010 Area

10 Mass Flow Rate, M L lb/hr 31,000 Liquid Volume11 Density, L lb/ft 31.0 Velocity12 Maximum Droplet Size, d M micron 300 Viscosity13 Slop Capacity, V S ft 66.8 Nozzle Diameter14 Holdup Time, (Slop Level to NLL), T H minute 30 TRUE FALSE15 Additional Holdup Volume to HLL, V XL ft 0.0 SELECTED DRUM DIMENSIONS UNIT VALUE

05/22/2011

V

A

P

O

R

L

I

Q

U

I

D

Single Entry Dual Entry

Fpsilb/hrft/hr

lb/ftftftftft/seccPin

ft/hr

15

API 521 Sample Calculation

16 Vapor Density, V lb/ft 0.180 KO Drum Pump(s) Capacity ft/hr 100.0017 Volumetric Vapor Rate, Q V ft/hr 938,889 Does Second Pump Start at HLL? -- No18 Liquid Holdup Capacity ft 500.0 Droplet Size for Selected Dimensions, d S micron 30319 Calculated Drum Diameter, D C ft 7.85 Selected Drum Diameter, D S ft 8.0020 Calculated Minimum Drum Length (T/T), L C ft 19.11 Selected Drum Length (T/T), L S ft 18.5021 Slop Height from Bottom, H SC ft 0.98 Slop Height from Bottom, H SS ft 1.0022 Liquid Holdup Height from Bottom (NLL), H NC ft 4.63 Liquid Holdup Ht (Normal Level), H NS ft 4.6923 High Liquid Level Height from Bottom, H LC ft 4.63 High Liquid Level Height, H LS ft 4.6924 Liquid Dropout Velocity, V DC ft/sec 2.35 Liquid Dropout Velocity, V DS ft/sec 2.3825 Liquid Dropout Time, T DC sec 1.37 Liquid Dropout Time, T DS sec 1.3926 Vapor Space Height, H VC ft 3.22 Vapor Space Height, H VS ft 3.3127 Vapor Space Cross Sectional Area, A VC ft 18.7 Vapor Space Cross Sectional Area, A VS ft 19.628 Vapor Velocity, V VC ft/sec 13.95 Vapor Velocity, V VS ft/sec 13.2929 C ( Re ) 2 -- 5,025 C ( Re ) 2 -- 5,18030 Drag Coefficient, C C -- 1.298 Drag Coefficient, C S -- 1.28431 Convergence Absolute Tolerance ft 0.00E+00 Iteration Weight -- 2.00

16

API 521Sample Calculation32 Nozzle Centerline to Tangent Nzzl. Centerline to Tan.33 ft 18.50 ft ft34 Inlet Nozzle Dia, in: Outlet Nzzle Dia, in: 35 12.00 12.0036

37 Liq Levels From Bottom ( ft ) Section Vol Residence Time, minute38 HHLL (ESD) 4.49 ( ft ) Incoming Outgoing (2) Note 339 HLL (2nd Pump Starts) 4.69 -29.5 -1.8 -17.7 -2.040 NLL (1st Pump Starts) 4.69 0.0 0.0 0.0 0.0 Add Holdup41 Slop Level 1.00 500.0 30.0 300.0 33.3 Liq Holdup42 LLL (Both Pumps Stop) 0.00 66.8 4.0 40.1 4.5 Slop Cap43 0.0 0.0 0.0 0.0 Dead Vol

44 18.50 ft45

46 NOTES47 1. Do NOT link entry cells (cells highlighted blue) to other cells. These cells SHOULD contain a numeric value.48 2. Residence time for each section based on the capacity of one pump.49 3. This is the residence time for each section based on the balance of the incoming liquid flow and the outgoing pump-out rate by one pump.50 Negative numbers (if applicable) mean the pump-out rate is greater than the incoming flow rate.51

52

53

8.0 ft

Vapor Space

17

Knockout Drum Spreadsheet - 1

FLARE KNOCK OUT DRUMClient: JACOBS

Project: API 521 SAMPLE CALCULATION - 1Subject: FLARE KNOCK OUT DRUM

Calc No: XXX-XXXX-XXXXX-000 File No: XXX-XXXX-XXXXX-0001 DESCRIPTION UNIT VALUE2 Drum Temperature, t F 300.03 Drum Pressure, P psi-g 2.04 Estimated L/D Ratio, R E -- 2.445 Mass Flow Rate, M V lb/hr 169,0006 Molecular Weight, MW V lb/lbmole7 Compressibility Factor, Z V --8 Density, V lb/ft 0.1809 Viscosity, V cP 0.010

10 Mass Flow Rate, M L lb/hr 31,00011 Density, L lb/ft 31.012 Maximum Droplet Size, d M micron 30013 Slop Capacity, V S ft 66.814 Holdup Time, (Slop Level to NLL), T H minute 3015 Additional Holdup Volume to HLL, V XL ft 0.0

V

A

P

O

R

L

I

Q

U

I

D

18

Knockout Drum Spreadsheet - 216 Vapor Density, V lb/ft 0.18017 Volumetric Vapor Rate, Q V ft/hr 938,88918 Liquid Holdup Capacity ft 500.019 Calculated Drum Diameter, D C ft 7.8520 Calculated Minimum Drum Length (T/T), L C ft 19.1121 Slop Height from Bottom, H SC ft 0.9822 Liquid Holdup Height from Bottom (NLL), H NC ft 4.6323 High Liquid Level Height from Bottom, H LC ft 4.6324 Liquid Dropout Velocity, V DC ft/sec 2.3525 Liquid Dropout Time, T DC sec 1.3726 Vapor Space Height, H VC ft 3.2227 Vapor Space Cross Sectional Area, A VC ft 18.728 Vapor Velocity, V VC ft/sec 13.9529 C ( Re ) 2 -- 5,02530 Drag Coefficient, C C -- 1.29831 Convergence Absolute Tolerance ft 0.00E+00

19

Knockout Drum Spreadsheet - 3SELECTED DRUM DIMENSIONS UNIT VALUEKO Drum Pump(s) Capacity ft/hr 100.00Does Second Pump Start at HLL? -- NoDroplet Size for Selected Dimensions, d S micron 303Selected Drum Diameter, D S ft 8.00Selected Drum Length (T/T), L S ft 18.50Slop Height from Bottom, H SS ft 1.00Liquid Holdup Ht (Normal Level), H NS ft 4.69High Liquid Level Height, H LS ft 4.69Liquid Dropout Velocity, V DS ft/sec 2.38Liquid Dropout Time, T DS sec 1.39Vapor Space Height, H VS ft 3.31Vapor Space Cross Sectional Area, A VS ft 19.6Vapor Velocity, V VS ft/sec 13.29C ( Re ) 2 -- 5,180Drag Coefficient, C S -- 1.284Iteration Weight -- 2.00

20

Knockout Drum Spreadsheet - 432 Nozzle Centerline to Tangent Nzzl. Centerline to Tan.33 ft 18.50 ft ft34 Inlet Nozzle Dia, in: Outlet Nzzle Dia, in: 35 12.00 12.0036

37 Liq Levels From Bottom ( ft ) Section Vol Residence Time, minute38 HHLL (ESD) 4.49 ( ft ) Incoming Outgoing (2) Note 339 HLL (2nd Pump Starts) 4.69 -29.5 -1.8 -17.7 -2.040 NLL (1st Pump Starts) 4.69 0.0 0.0 0.0 0.0 Add Holdup41 Slop Level 1.00 500.0 30.0 300.0 33.3 Liq Holdup42 LLL (Both Pumps Stop) 0.00 66.8 4.0 40.1 4.5 Slop Cap43 0.0 0.0 0.0 0.0 Dead Vol

44 18.50 ft45

46 NOTES47 1. Do NOT link entry cells (cells highlighted blue) to other cells. These cells SHOULD contain a numeric value.48 2. Residence time for each section based on the capacity of one pump.49 3. This is the residence time for each section based on the balance of the incoming liquid flow and the outgoing pump-out rate by one pump.50 Negative numbers (if applicable) mean the pump-out rate is greater than the incoming flow rate.51

52

53

8.0 ft

Vapor Space

21

Spreadsheet Features UOMUNITS OF MEASUREMENT

TemperaturePressureMass Flow RateLiquid Volumetric Flow RateVapor Volumetric Flow RateDensityDimensionAreaLiquid VolumeVelocityViscosityNozzle Diameter

TRUE FALSESingle Entry Dual Entry

Fpsilb/hrft/hr


ft/hr

22

Spreadsheet Features UOM

23

Spreadsheet Features UOM

24

Nozzle Centerline to Tangent Nzzl. Centerline to Tan.

ft 18.50 ft ft

Inlet Nozzle Dia, in: Outlet Nzzle Dia, in:

12.00 12.00

Liq Levels From Bottom ( ft ) Section Vol Residence Time, minuteHHLL (ESD) 4.49 ( ft ) Incoming Outgoing (2) Note 3HLL (2nd Pump Starts) 4.69 -29.5 -1.8 -17.7 -2.0NLL (1st Pump Starts) 4.69 0.0 0.0 0.0 0.0 Add HoldupSlop Level 1.00 500.0 30.0 300.0 33.3 Liq Holdup

LLL (Both Pumps Stop) 0.00 66.8 4.0 40.1 4.5 Slop Cap0.0 0.0 0.0 0.0 Dead Vol

18.50 ft

8.0 ft

Vapor Space

Features Number of Entry Nozzles

Nozzle DiameterTRUE FALSE

SELECTED DRUM DIMENSIONS UNIT VALUESingle Entry Dual Entry

in

25


ft 18.50 ft 0.00 ft

Inlet Nozzles Dia, in:

12.00

Outlet Nzzle Dia, in: 12.00



18.50 ft

8.0 ft

Vapor Space

Features Number of Entry Nozzles

Nozzle DiameterFALSE TRUE

SELECTED DRUM DIMENSIONS UNIT VALUESingle Entry Dual Entry

in

26

16 Vapor Density, V lb/ft 0.18017 Volumetric Vapor Rate, Q V ft/hr 938,88918 Liquid Holdup Capacity ft 500.019 Calculated Drum Diameter, D C ft 7.8520 Calculated Minimum Drum Length (T/T), L C ft 19.1121 Slop Height from Bottom, H SC ft 0.9822 Liquid Holdup Height from Bottom (NLL), H NC ft 4.6323 High Liquid Level Height from Bottom, H LC ft 4.6324 Liquid Dropout Velocity, V DC ft/sec 2.3525 Liquid Dropout Time, T DC sec 1.3726 Vapor Space Height, H VC ft 3.2227 Vapor Space Cross Sectional Area, A VC ft 18.728 Vapor Velocity, V VC ft/sec 13.9529 C ( Re ) 2 -- 5,02530 Drag Coefficient, C C -- 1.29831 Convergence Absolute Tolerance ft 0.00E+00

Features Iterative Calculations

1 DESCRIPTION UNIT VALUE2 Drum Temperature, t F 300.03 Drum Pressure, P bar-g 0.1384 Estimated L/D Ratio, R E -- 2.445 Mass Flow Rate, M V lb/hr 169,0006 Molecular Weight, MW V lb/lbmole7 Compressibility Factor, Z V --8 Density, V lb/ft 0.1809 Viscosity, V cP 0.010

10 Mass Flow Rate, M L lb/hr 31,00011 Density, L lb/ft 31.012 Maximum Droplet Size, d M micron 30013 Slop Capacity, V S ft 66.814 Holdup Time, (Slop Level to NLL), T H minute 3015 Additional Holdup Volume to HLL, V XL ft 0.0

V

A

P

O

R

L

I

Q

U

I

D

Entered DataCalculated Values

27

FLARE KNOCK OUT DRUM PROG NO: JE-103 Converg. AreaClient: JACOBS Prepared By: Date: Check Tolerance

Project: API 521 SAMPLE CALCULATION - 1 Checked By: Job No: XXXXX-100 R FALSE 8.96E-05Subject: FLARE KNOCK OUT DRUM Tag No: V-XXXX E FALSE -6.86E-10

Calc No: XXX-XXXX-XXXXX-000 File No: XXX-XXXX-XXXXX-000 Sheet: 1 of 1 V FALSE -9.89E-101 DESCRIPTION UNIT VALUE UNITS OF MEASUREMENT FALSE 9.89E-102 Drum Temperature, t F 300.0 Temperature FALSE Converg.3 Drum Pressure, P psi-g 2.0 Pressure FALSE Tolerance4 Estimated L/D Ratio, R E -- 2.44 Mass Flow Rate FALSE 5.56E-095 Mass Flow Rate, M V lb/hr 169,000 Liquid Volumetric Flow Rate FALSE 0.00E+006 Molecular Weight, MW V lb/lbmole 79.11 Vapor Volumetric Flow Rate FALSE 4.11E-157 Compressibility Factor, Z V -- 0.900 Density FALSE -3.55E-158 Density, V lb/ft Dimension FALSE9 Viscosity, V cP 0.010 Area FALSE

10 Mass Flow Rate, M L lb/hr 31,000 Liquid Volume FALSE11 Density, L lb/ft 31.0 Velocity FALSE12 Maximum Droplet Size, d M micron 300 Viscosity FALSE13 Slop Capacity, V S ft 66.8 Nozzle Diameter FALSE14 Holdup Time, (Slop Level to NLL), T H minute 30 FALSE TRUE FALSE15 Additional Holdup Volume to HLL, V XL ft 26.7 SELECTED DRUM DIMENSIONS UNIT VALUE FALSE16 Vapor Density, V lb/ft 0.180 KO Drum Pump(s) Capacity gpm 12.47 FALSE17 Volumetric Vapor Rate, Q V ft/hr 938,839 Does Second Pump Start at HLL? -- No FALSE

05/08/2011

V

A

P

O

R

L

I

Q

U

I

D


Fpsilb/hrgpm


ft/hr

Features Convergence

Keep Hitting F9 till all the Convergence Checks turns True

28

Features ConvergenceFLARE KNOCK OUT DRUM PROG NO: JE-103 Converg. Area

Client: JACOBS Prepared By: Date: Check ToleranceProject: API 521 SAMPLE CALCULATION - 1 Checked By: Job No: XXXXX-100 R TRUE 0.00E+00Subject: FLARE KNOCK OUT DRUM Tag No: V-XXXX E TRUE 0.00E+00

Calc No: XXX-XXXX-XXXXX-000 File No: XXX-XXXX-XXXXX-000 Sheet: 1 of 1 V TRUE 0.00E+001 DESCRIPTION UNIT VALUE UNITS OF MEASUREMENT TRUE 0.00E+002 Drum Temperature, t F 300.0 Temperature TRUE Converg.3 Drum Pressure, P bar-g 0.138 Pressure TRUE Tolerance4 Estimated L/D Ratio, R E -- 2.44 Mass Flow Rate TRUE 0.00E+005 Mass Flow Rate, M V lb/hr 169,000 Liquid Volumetric Flow Rate TRUE 0.00E+006 Molecular Weight, MW V lb/lbmole Vapor Volumetric Flow Rate TRUE 0.00E+007 Compressibility Factor, Z V -- Density TRUE 0.00E+008 Density, V lb/ft 0.180 Dimension TRUE9 Viscosity, V cP 0.010 Area TRUE

10 Mass Flow Rate, M L lb/hr 31,000 Liquid Volume TRUE11 Density, L lb/ft 31.0 Velocity TRUE12 Maximum Droplet Size, d M micron 300 Viscosity TRUE13 Slop Capacity, V S ft 66.8 Nozzle Diameter TRUE14 Holdup Time, (Slop Level to NLL), T H minute 30 FALSE TRUE TRUE15 Additional Holdup Volume to HLL, V XL ft 0.0 SELECTED DRUM DIMENSIONS UNIT VALUE TRUE16 Vapor Density, V lb/ft 0.180 KO Drum Pump(s) Capacity ft/hr 100.00 TRUE17 Volumetric Vapor Rate, Q V ft/hr 938,889 Does Second Pump Start at HLL? -- No TRUE

05/22/2011

V

A

P

O

R

L

I

Q

U

I

D


Fbarlb/hrft/hr


ft/hr

Keep Hitting F9 till all the Convergence Checks turns True

29

SELECTED DRUM DIMENSIONS UNIT VALUE

Features Selecting Drum Dimensions

16 Vapor Density, V lb/ft 0.180 KO Drum Pump(s) Capacity gpm 12.4717 Volumetric Vapor Rate, Q V ft/hr 938,889 Does Second Pump Start at HLL? -- No18 Liquid Holdup Capacity ft 500.0 Droplet Size for Selected Dimensions, d S micron 30319 Calculated Drum Diameter, D C ft 7.93 Selected Drum Diameter, D S ft 8.0020 Calculated Minimum Drum Length (T/T), L C ft 18.84 Selected Drum Length (T/T), L S ft 18.5021 Slop Height from Bottom, H SC ft 0.99 Slop Height from Bottom, H SS ft 1.0022 Liquid Holdup Height from Bottom (NLL), H NC ft 4.65 Liquid Holdup Ht (Normal Level), H NS ft 4.6923 High Liquid Level Height from Bottom, H LC ft 4.65 High Liquid Level Height, H LS ft 4.6924 Liquid Dropout Velocity, V DC ft/sec 2.35 Liquid Dropout Velocity, V DS ft/sec 2.3825 Liquid Dropout Time, T DC sec 1.40 Liquid Dropout Time, T DS sec 1.3926 Vapor Space Height, H VC ft 3.29 Vapor Space Height, H VS ft 3.3127 Vapor Space Cross Sectional Area, A VC ft 19.3 Vapor Space Cross Sectional Area, A VS ft 19.628 Vapor Velocity, V VC ft/sec 13.48 Vapor Velocity, V VS ft/sec 13.2929 C ( Re ) 2 -- 5,025 C ( Re ) 2 -- 5,18030 Drag Coefficient, C C -- 1.298 Drag Coefficient, C S -- 1.28431 Convergence Absolute Tolerance ft 1.37E-10 Iteration Weight -- 3.00

Calculated ValuesSelected Variables

30

ft 18.50 ft 0.00 ft


12.00




18.50 ft

8.0 ft

Vapor Space

Features Liquid Levels

Liq. Level Variable DefinitionLLL: Fixed Either the lower level tap or where pump(s) stop.Slop Level: Free Calculated based on slop volume.NLL: Free Calculated based on the holdup time (20-30 minutes)HLL Free Calculated based on Additional Holdup Volume. Normally the

second pump (if applicable) starts at this level.HHLL: Fixed Emergency Shut Down (if effective).Vapor Space Free Calculated from HLL to the top of drum.

31

Features Section Vol., & Resid. Timeft 18.50 ft 0.00 ft


12.00




18.50 ft

8.0 ft

Vapor Space

Section Volumes: Volume between the two liquid levels.Incoming Resid Time: Based on incoming liquid flow rate.Outgoing Resid Time: Based on capacity of one pump.Third Column (Note 3): Based on the balance of incoming liquid flow and

outgoing pump-out rate by one pump.

32

Features Effective Drum Length

Effective Length of the drum is between inlet and outlet nozzle centerlines. The distance from the nozzle centerline to head seam must be greater than half

of the nozzle diameter.


0.51 ft 17.40 ft 0.59 ft

Inlet Nozzle Dia, in: Outlet Nzzle Dia, in:

12.00 14.00



18.50 ft

8.0 ft

Vapor Space

33

Features Cell Comments

34

Questions and Discussions

Documents

Flare KO Drum-3