Flare KO Drum-3

June 16, 2011 Piruz Nezami

Overview

•

Introduction – Definitions and Functions

•

Design Parameters

•

Sizing Bases and Equations

•

API 521 Sample Calculation

•

Spreadsheet

1

Introduction 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. 2

Design Parameters 1.

Liquid droplet size limited to 300 to 600 µm 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.

3

Design 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 and high vapor flow. They have lower pressure drop than vertical drums.

●

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

4

Design 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. 5

Knockout 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.

6

Vapor Travel - Liquid Dropout Nozzle to Nozzle Distance, L N

HV

High Liquid Level HL

L TV = N VV T V : Vapor Residence Time L N : KO Drum Nozzle to Nozzle Length V V : Vapor Velocity

TD =

HV VD

T D : Liquid Dropout Time H V : Vapor Space Height V D : Liquid Dropout Velocity

7

Horizontal Knockout Drum Sizing Liquid Dropout Velocity:

g D (ρ L − ρV ) V D = 1.15 ρV C VD :

Liquid Dropout Velocity

g:

Gravitational Constant (9.8 m/s2, 32.2 ft/s2)

D:

Particle Diameter

ρL :

Liquid Density at Operating Conditions

ρV :

Vapor Density at Operating Conditions

C:

Drag Coefficient

8

Horizontal Knockout Drum Sizing Drag Coefficient:

(Cte ) ( ρV ) ( D )3 ( ρ L − ρV ) (C ) (Re) = ( µ )2 2

Re : Reynolds Number µ:

Vapor Viscosity at Operating Conditions

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

9

API 521 – ISO 23251 Sample Calculation Total Flow Rate:

200,000 lb/hr

Liquid Density

31 lb/ft3

Vapor Density

0.18 lb/ft3

Pressure:

2 psig

Temperature:

300 °F

Vapor Viscosity:

0.01 cP

The 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 µm. 10

API 521 – ISO 23251 Sample Calculation

RV= 169,000 / (3,600 x 0.18)

Actual Vapor Rate Drag Coefficient x Re2

C x Re2= [ 0.95 x 108 x 0.18 x (0.000984)3 x (31 - 0.18) ] / (0.01)2

Dropout Velocity

UC= 1.15 * [ 32.2 X 0.000984 x (31 - 0.18) / (0.18 x 1.3) ]0.5

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= π x D2 / 4

Vapor Cross Sectional Area

AV= AT - AS - AH

11

= = =

261 ft3/sec 5,021 2.35 ft/sec

API 521 – ISO 23251 Sample Calculation

AV

HH

HT (D) α β

1 AH + AS = × [ β − Sin (β ) ] × D 2 8

AH

HH

AS =

AS

HS

12

1 × [ α − Sin (α ) ] × D 2 8

API 521 – ISO 23251 Sample Calculation

Diameter Length

Cross Sectional Area

Vertical Height

Dropout

Vapor Minimum

D

L

AT

AS

AH

AV

HT (D)

HS + HH

HV

ft

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

13

Time, TD Vel, VV Length, L

API 521 Sample calculation FLARE KNOCK OUT DRUM

PROG NO: JE-103 05/22/2011

JACOBS

Prepared By:

Date:

Project:

API 521 SAMPLE CALCULATION - 1

Checked By:

Job No:

XXXXX-100

R

Subject:

FLARE KNOCK OUT DRUM

Tag No:

V-XXXX

E

Calc No:

XXX-XXXX-XXXXX-000

Client:

1

DESCRIPTION

2

Drum Temperature, t

3

Drum Pressure, P

4

Estimated L/D Ratio, R E Mass Flow Rate, M V

6

Molecular Weight, MW V

7 8

VAPOR

5

9

Compressibility Factor, Z V

File No:

UNIT °F

XXX-XXXX-XXXXX-000 VALUE 300.0

psi-g

2.0

--

2.44

lb/hr

169,000

lb/lbmole --

Sheet:

1

of

Temperature

°F

Pressure

psi

Mass Flow Rate

lb/hr

Liquid Volumetric Flow Rate

ft³/hr

Vapor Volumetric Flow Rate

ft³/hr

Density

lb/ft³

Density, ρ V

lb/ft³

0.180

Dimension

ft

Viscosity, µV

cP

0.010

Area

ft²

Liquid Volume

ft³

lb/hr

31,000

11

Density, ρ L

lb/ft³

31.0

Velocity

ft/sec

micron

300

Viscosity

cP

ft³

66.8

Nozzle Diameter

in

13

LIQUID

Mass Flow Rate, M L Maximum Droplet Size, d M Slop Capacity, V S

14

Holdup Time, (Slop Level to NLL), T H

minute

30

15

Additional Holdup Volume to HLL, V XL

ft³

0.0

14

V

UNITS OF MEASUREMENT

10

12

1

Single Entry

TRUE

SELECTED DRUM DIMENSIONS

Dual Entry

FALSE

UNIT

VALUE

API 521 Sample Calculation 16

Vapor Density, ρV

lb/ft³

17

Volumetric Vapor Rate, Q V

ft³/hr

18

Liquid Holdup Capacity

ft³

19

Calculated Drum Diameter, D C

ft

20

Calculated Minimum Drum Length (T/T), L C

ft

21

Slop Height from Bottom, H SC

22

0.180 KO Drum Pump(s) Capacity

100.00

--

No

micron

303

ft

8.00

19.11 Selected Drum Length (T/T), L S

ft

18.50

ft

0.98 Slop Height from Bottom, H SS

ft

1.00

Liquid Holdup Height from Bottom (NLL), H NC

ft

4.63 Liquid Holdup Ht (Normal Level), H NS

ft

4.69

23

High Liquid Level Height from Bottom, H LC

ft

4.63 High Liquid Level Height, H LS

ft

4.69

24

Liquid Dropout Velocity, V DC

ft/sec

2.35 Liquid Dropout Velocity, V DS

ft/sec

2.38

25

Liquid Dropout Time, T DC

sec

1.37 Liquid Dropout Time, T DS

sec

1.39

26

Vapor Space Height, H VC

ft

3.22 Vapor Space Height, H VS

ft

3.31

27

Vapor Space Cross Sectional Area, A VC

ft²

18.7 Vapor Space Cross Sectional Area, A VS

ft²

19.6

28

Vapor Velocity, V VC

ft/sec

13.95 Vapor Velocity, V VS

ft/sec

13.29

29

--

5,025 C ( Re ) 2 1.298 Drag Coefficient, C S

--

5,180

30

C ( Re ) 2 Drag Coefficient, C C

--

1.284

31

Convergence Absolute Tolerance

ft

--

2.00

--

938,889 Does Second Pump Start at HLL?

ft³/hr

500.0 Droplet Size for Selected Dimensions, d S 7.85 Selected Drum Diameter, D S

0.00E+00 Iteration Weight

15

API 521Sample Calculation 32

Nozzle Centerline to Tangent

33

Nzzl. Centerline to Tan. ft

34

18.50 ft

ft

Inlet Nozzle Dia, in:

35

Outlet Nzzle Dia, in:

12.00

12.00

36 37

Liq Levels From Bottom

( ft )

Section Vol

38

HHLL (ESD)

4.49

( ft³ )

Incoming

Outgoing (2)

Note 3

39

Residence Time, minute

Vapor Space

HLL (2nd Pump Starts)

4.69

-29.5

-1.8

-17.7

-2.0

40

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

41

Slop Level

1.00

500.0

30.0

300.0

33.3

Liq Holdup

42

LLL (Both Pumps Stop)

0.00

66.8

4.0

40.1

4.5

Slop Cap

0.0

0.0

0.0

0.0

Dead Vol

8.0 ft

43 44

18.50 ft

45 46

NOTES

47

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

16

Knockout Drum Spreadsheet - 1 FLARE KNOCK OUT DRUM Client:

JACOBS

Project:

API 521 SAMPLE CALCULATION - 1

Subject:

FLARE KNOCK OUT DRUM

Calc No:

XXX-XXXX-XXXXX-000

1

DESCRIPTION

2

Drum Temperature, t

3

Drum Pressure, P

4

Estimated L/D Ratio, R E Mass Flow Rate, M V

6

Molecular Weight, MW V

7 8

VAPOR

5

9

File No:

UNIT °F

XXX-XXXX-XXXXX-000 VALUE 300.0

psi-g

2.0

--

2.44

lb/hr

169,000

lb/lbmole

Compressibility Factor, Z V

--

Density, ρ V

lb/ft³

0.180

Viscosity, µV

cP

0.010

Mass Flow Rate, M L

lb/hr

31,000

11

Density, ρ L

lb/ft³

31.0

micron

300

ft³

66.8

12 13

LIQUID

10

Maximum Droplet Size, d M Slop Capacity, V S

14

Holdup Time, (Slop Level to NLL), T H

minute

30

15

Additional Holdup Volume to HLL, V XL

ft³

0.0

17

Knockout Drum Spreadsheet - 2 16

Vapor Density, ρV

lb/ft³

0.180

17

Volumetric Vapor Rate, Q V

ft³/hr

938,889

18

Liquid Holdup Capacity

ft³

500.0

19

Calculated Drum Diameter, D C

ft

7.85

20

Calculated Minimum Drum Length (T/T), L C

ft

19.11

21

Slop Height from Bottom, H SC

ft

0.98

22

Liquid Holdup Height from Bottom (NLL), H NC

ft

4.63

23

High Liquid Level Height from Bottom, H LC

ft

4.63

24

Liquid Dropout Velocity, V DC

ft/sec

2.35

25

Liquid Dropout Time, T DC

sec

1.37

26

Vapor Space Height, H VC

ft

3.22

27

Vapor Space Cross Sectional Area, A VC

ft²

18.7

28

Vapor Velocity, V VC

ft/sec

13.95

29

--

5,025

30

C ( Re ) 2 Drag Coefficient, C C

--

1.298

31

Convergence Absolute Tolerance

ft

0.00E+00

18

Knockout Drum Spreadsheet - 3 SELECTED DRUM DIMENSIONS

UNIT

VALUE

KO Drum Pump(s) Capacity

ft³/hr

100.00

Does Second Pump Start at HLL?

--

No

micron

303

Selected Drum Diameter, D S

ft

8.00

Selected Drum Length (T/T), L S

ft

18.50

Slop Height from Bottom, H SS

ft

1.00

Liquid Holdup Ht (Normal Level), H NS

ft

4.69

High Liquid Level Height, H LS

ft

4.69

Liquid Dropout Velocity, V DS

ft/sec

2.38

Liquid Dropout Time, T DS

sec

1.39

Vapor Space Height, H VS

ft

3.31

Vapor Space Cross Sectional Area, A VS

ft²

19.6

Vapor Velocity, V VS

ft/sec

13.29

C ( Re ) 2 Drag Coefficient, C S

--

5,180

--

1.284

Iteration Weight

--

2.00

Droplet Size for Selected Dimensions, d S

19

Knockout Drum Spreadsheet - 4 32

Nozzle Centerline to Tangent

33

Nzzl. Centerline to Tan. ft

34

18.50 ft

ft

Inlet Nozzle Dia, in:

35

Outlet Nzzle Dia, in:

12.00

12.00

36 37

Liq Levels From Bottom

( ft )

Section Vol

38

HHLL (ESD)

4.49

( ft³ )

Incoming

Outgoing (2)

Note 3

HLL (2nd Pump Starts)

4.69

-29.5

-1.8

-17.7

-2.0

40

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

41

Slop Level

1.00

500.0

30.0

300.0

33.3

Liq Holdup

42

LLL (Both Pumps Stop)

0.00

66.8

4.0

40.1

4.5

Slop Cap

0.0

0.0

0.0

0.0

Dead Vol

39

8.0 ft

43 44

Residence Time, minute

18.50 ft

45 46

NOTES

47

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

20

Vapor Space

Spreadsheet Features UOM UNITS OF MEASUREMENT Temperature

°F

Pressure

psi

Mass Flow Rate

lb/hr

Liquid Volumetric Flow Rate

ft³/hr

Vapor Volumetric Flow Rate

ft³/hr

Density

lb/ft³

Dimension

ft

Area

ft²

Liquid Volume

ft³

Velocity

ft/sec

Viscosity

cP

Nozzle Diameter

in

Single Entry

Dual Entry

TRUE

21

FALSE

Spreadsheet Features UOM

22

Spreadsheet Features – UOM

23

Features – Number of Entry Nozzles in

Nozzle Diameter Single Entry

Dual Entry

TRUE

SELECTED DRUM DIMENSIONS

FALSE

UNIT

VALUE

Nozzle Centerline to Tangent

Nzzl. Centerline to Tan. ft

18.50 ft

ft

Inlet Nozzle Dia, in:

Outlet Nzzle Dia, in:

12.00

8.0 ft

12.00

Liq Levels From Bottom

( ft )

Section Vol

HHLL (ESD)

4.49

( ft³ )

Incoming

Outgoing (2)

Note 3

HLL (2nd Pump Starts)

4.69

-29.5

-1.8

-17.7

-2.0

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

Slop 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 Cap

0.0

0.0

0.0

0.0

Dead Vol

18.50 ft

24

Residence Time, minute

Vapor Space

Features – Number of Entry Nozzles in

Nozzle Diameter Single Entry

Dual Entry

FALSE

SELECTED DRUM DIMENSIONS

TRUE

UNIT

VALUE

Nozzle Centerline to Tangent

Nzzl. Centerline to Tan. ft

18.50 ft

0.00

ft

Inlet Nozzles Dia, in: 12.00 Outlet Nzzle Dia, in:

8.0 ft

12.00

Liq Levels From Bottom

( ft )

Section Vol

HHLL (ESD)

4.49

( ft³ )

Incoming

Outgoing (2)

Note 3

HLL (2nd Pump Starts)

4.69

-29.5

-1.8

-17.7

-2.0

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

Slop 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 Cap

0.0

0.0

0.0

0.0

Dead Vol

18.50 ft

25

Residence Time, minute

Vapor Space

Features – Iterative Calculations Calculated Values Entered Data 1

DESCRIPTION

2

Drum Temperature, t

3

Drum Pressure, P

4

Estimated L/D Ratio, R E

16

Vapor Density, ρV

lb/ft³

0.180

VALUE

17

Volumetric Vapor Rate, Q V

ft³/hr

938,889

°F

300.0

18

Liquid Holdup Capacity

ft³

500.0

bar-g

0.138

19

Calculated Drum Diameter, D C

ft

7.85

--

2.44

20

Calculated Minimum Drum Length (T/T), L C

ft

19.11

169,000

21

Slop Height from Bottom, H SC

ft

0.98

22

Liquid Holdup Height from Bottom (NLL), H NC

ft

4.63

23

High Liquid Level Height from Bottom, H LC

ft

4.63

24

Liquid Dropout Velocity, V DC

ft/sec

2.35

25

Liquid Dropout Time, T DC

sec

1.37

26

Vapor Space Height, H VC

ft

3.22

ft²

18.7

UNIT

Mass Flow Rate, M V

6

Molecular Weight, MW V

lb/lbmole

Compressibility Factor, Z V

--

7 8

VAPOR

5

9

lb/hr

Density, ρ V

lb/ft³

0.180

Viscosity, µV

cP

0.010

Mass Flow Rate, M L

lb/hr

31,000

11

Density, ρ L

lb/ft³

31.0

micron

300

27

Vapor Space Cross Sectional Area, A VC

ft³

66.8

28

Vapor Velocity, V VC

ft/sec

13.95

--

5,025

--

1.298

ft

0.00E+00

12 13

L IQ U ID

10

Maximum Droplet Size, d M Slop Capacity, V S

14

Holdup Time, (Slop Level to NLL), T H

minute

30

29

15

Additional Holdup Volume to HLL, V XL

ft³

0.0

30

C ( Re ) 2 Drag Coefficient, C C

31

Convergence Absolute Tolerance

26

Features – Convergence FLARE KNOCK OUT DRUM

PROG NO: JE-103 05/08/2011

Converg.

Area

Check

Tolerance

JACOBS

Prepared By:

Date:

Project:

API 521 SAMPLE CALCULATION - 1

Checked By:

Job No:

XXXXX-100

R

FALSE

8.96E-05

Subject:

FLARE KNOCK OUT DRUM

Tag No:

V-XXXX

E

FALSE

-6.86E-10

Calc No:

XXX-XXXX-XXXXX-000

V

FALSE

-9.89E-10

FALSE

9.89E-10

Client:

1

DESCRIPTION

2

Drum Temperature, t

3

Drum Pressure, P

4

Estimated L/D Ratio, R E

File No:

UNIT

Molecular Weight, MW V

lb/lbmole

Compressibility Factor, Z V

--

VAPO R

6

9

Density, ρ V

lb/ft³

Viscosity, µV

cP

of

1

FALSE

Converg.

psi

FALSE

Tolerance

lb/hr

FALSE

5.56E-09

169,000 Liquid Volumetric Flow Rate

gpm

FALSE

0.00E+00

79.11 Vapor Volumetric Flow Rate

ft³/hr

FALSE

4.11E-15

0.900 Density

lb/ft³

FALSE

-3.55E-15

ft

FALSE

ft²

FALSE

ft³

FALSE

2.0 Pressure

lb/hr

1

°F

psi-g --

Sheet:

UNITS OF MEASUREMENT

300.0 Temperature

Mass Flow Rate, M V

8

VALUE

°F

5

7

XXX-XXXX-XXXXX-000

2.44 Mass Flow Rate

Dimension 0.010 Area

Mass Flow Rate, M L

lb/hr

11

Density, ρ L

lb/ft³

31.0 Velocity

ft/sec

FALSE

micron

300 Viscosity

cP

FALSE

66.8 Nozzle Diameter

in

12 13

L IQ U ID

10

Maximum Droplet Size, d M Slop Capacity, V S

ft³

14

Holdup Time, (Slop Level to NLL), T H

minute

15

Additional Holdup Volume to HLL, V XL

ft³

16

Vapor Density, ρV

lb/ft³

17

Volumetric Vapor Rate, Q V

ft³/hr

31,000 Liquid Volume

30

Single Entry

FALSE

26.7 SELECTED DRUM DIMENSIONS 0.180 KO Drum Pump(s) Capacity 938,839 Does Second Pump Start at HLL?

FALSE

Dual Entry

TRUE

FALSE

UNIT

VALUE

FALSE

gpm

12.47

FALSE

No

FALSE

--

Keep Hitting F9 till all the Convergence Checks turns “True” 27

Features – Convergence FLARE KNOCK OUT DRUM

PROG NO: JE-103 05/22/2011

Converg.

Area

Check

Tolerance

JACOBS

Prepared By:

Date:

Project:

API 521 SAMPLE CALCULATION - 1

Checked By:

Job No:

XXXXX-100

R

TRUE

0.00E+00

Subject:

FLARE KNOCK OUT DRUM

Tag No:

V-XXXX

E

TRUE

0.00E+00

Calc No:

XXX-XXXX-XXXXX-000

V

TRUE

0.00E+00

Client:

1

DESCRIPTION

2

Drum Temperature, t

3

Drum Pressure, P

4

Estimated L/D Ratio, R E Mass Flow Rate, M V

6

Molecular Weight, MW V

7 8

VA PO R

5

9

Compressibility Factor, Z V

File No:

UNIT °F bar-g -lb/hr

XXX-XXXX-XXXXX-000 VALUE

Viscosity, µV

cP

of

1

UNITS OF MEASUREMENT

TRUE TRUE

Converg.

0.138 Pressure

bar

TRUE

Tolerance

lb/hr

TRUE

0.00E+00

169,000 Liquid Volumetric Flow Rate

ft³/hr

TRUE

0.00E+00

Vapor Volumetric Flow Rate

ft³/hr

TRUE

0.00E+00

Density

lb/ft³

TRUE

0.00E+00

0.180 Dimension

ft

TRUE

0.010 Area

ft²

TRUE

ft³

TRUE

2.44 Mass Flow Rate

Mass Flow Rate, M L

lb/hr

11

Density, ρ L

lb/ft³

31.0 Velocity

ft/sec

TRUE

micron

300 Viscosity

cP

TRUE

in

TRUE

13

LIQ U ID

10

12

Maximum Droplet Size, d M Slop Capacity, V S

ft³

14

Holdup Time, (Slop Level to NLL), T H

minute

15

Additional Holdup Volume to HLL, V XL

ft³

16

Vapor Density, ρV

lb/ft³

17

Volumetric Vapor Rate, Q V

ft³/hr

0.00E+00

°F

-lb/ft³

1

300.0 Temperature

lb/lbmole

Density, ρ V

Sheet:

31,000 Liquid Volume

66.8 Nozzle Diameter 30

Single Entry

FALSE

0.0 SELECTED DRUM DIMENSIONS 0.180 KO Drum Pump(s) Capacity 938,889 Does Second Pump Start at HLL?

Dual Entry

TRUE

TRUE

UNIT

VALUE

TRUE

ft³/hr

100.00

TRUE

No

TRUE

--

Keep Hitting F9 till all the Convergence Checks turns “True” 28

Features – Selecting Drum Dimensions Selected Variables Calculated Values 16

Vapor Density, ρV

lb/ft³

17

Volumetric Vapor Rate, Q V

ft³/hr

18

Liquid Holdup Capacity

ft³

19

Calculated Drum Diameter, D C

ft

20

Calculated Minimum Drum Length (T/T), L C

ft

21

Slop Height from Bottom, H SC

22

SELECTED DRUM DIMENSIONS 0.180 KO Drum Pump(s) Capacity

VALUE 12.47

--

No

micron

303

ft

8.00

18.84 Selected Drum Length (T/T), L S

ft

18.50

ft

0.99 Slop Height from Bottom, H SS

ft

1.00

Liquid Holdup Height from Bottom (NLL), H NC

ft

4.65 Liquid Holdup Ht (Normal Level), H NS

ft

4.69

23

High Liquid Level Height from Bottom, H LC

ft

4.65 High Liquid Level Height, H LS

ft

4.69

24

Liquid Dropout Velocity, V DC

ft/sec

2.35 Liquid Dropout Velocity, V DS

ft/sec

2.38

25

Liquid Dropout Time, T DC

sec

1.40 Liquid Dropout Time, T DS

sec

1.39

26

Vapor Space Height, H VC

ft

3.29 Vapor Space Height, H VS

ft

3.31

27

Vapor Space Cross Sectional Area, A VC

ft²

19.3 Vapor Space Cross Sectional Area, A VS

ft²

19.6

28

Vapor Velocity, V VC

ft/sec

13.48 Vapor Velocity, V VS

ft/sec

13.29

29

--

5,025 C ( Re ) 2 1.298 Drag Coefficient, C S

--

5,180

30

C ( Re ) 2 Drag Coefficient, C C

--

1.284

31

Convergence Absolute Tolerance

ft

--

3.00

--

938,889 Does Second Pump Start at HLL?

UNIT gpm

500.0 Droplet Size for Selected Dimensions, d S 7.93 Selected Drum Diameter, D S

1.37E-10 Iteration Weight 29

Features – Liquid Levels ft

18.50 ft

0.00

ft

Inlet Nozzles Dia, in: 12.00 Outlet Nzzle Dia, in:

8.0 ft

14.00

Liq Levels From Bottom

( ft )

Section Vol

Residence Time, minute

HHLL (ESD)

0.00

( ft³ )

Incoming

Outgoing (2)

Note 3

HLL (2nd Pump Starts)

4.69

-566.8

-34.0

-340.1

-37.8

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

Slop 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 Cap

0.0

0.0

0.0

0.0

Dead Vol

18.50 ft

Liq. Level LLL: Slop Level: NLL: HLL

Variable Fixed Free Free Free

HHLL: Vapor Space

Fixed Free

Definition Either the lower level tap or where pump(s) stop. Calculated based on slop volume. Calculated based on the holdup time (20-30 minutes) Calculated based on “Additional Holdup Volume”. Normally the second pump (if applicable) starts at this level. Emergency Shut Down (if effective). Calculated from HLL to the top of drum. 30

Vapor Space

Features – Section Vol., & Resid. Time ft

18.50 ft

0.00

ft

Inlet Nozzles Dia, in: 12.00 Outlet Nzzle Dia, in:

8.0 ft

14.00

Liq Levels From Bottom

( ft )

Section Vol

Residence Time, minute

HHLL (ESD)

0.00

( ft³ )

Incoming

Outgoing (2)

Note 3

HLL (2nd Pump Starts)

4.69

-566.8

-34.0

-340.1

-37.8

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

Slop 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 Cap

0.0

0.0

0.0

0.0

Dead Vol

18.50 ft

Section Volumes: Incoming Resid Time: Outgoing Resid Time: Third Column (Note 3):

Volume between the two liquid levels. Based on incoming liquid flow rate. Based on capacity of one pump. Based on the balance of incoming liquid flow and outgoing pump-out rate by one pump. 31

Vapor Space

Features – Effective Drum Length Nozzle Centerline to Tangent 0.51

Nzzl. Centerline to Tan. ft

17.40 ft

0.59

Inlet Nozzle Dia, in:

Outlet Nzzle Dia, in:

12.00

8.0 ft

ft

14.00

Liq Levels From Bottom

( ft )

Section Vol

Residence Time, minute

HHLL (ESD)

0.00

( ft³ )

Incoming

Outgoing (2)

Note 3

HLL (2nd Pump Starts)

4.69

-566.8

-34.0

-340.1

-37.8

NLL (1st Pump Starts)

4.69

0.0

0.0

0.0

0.0

Add Holdup

Slop 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 Cap

0.0

0.0

0.0

0.0

Dead Vol

Vapor Space

18.50 ft

● ●

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.

32

Features – Cell Comments

33

Questions and Discussions

34