IPE-TM-300 Vessels
Vessel Sizing Guidelines Attachments (1)
IPE-TM-300-04
Vessel Sizing Guidelines Attachment Index
Vessel Sizing Guidelines Attachment Index 31
Attachment 1 - Derivation of Equations for Horizontal Vessels 32
Attachment 1.1 Liquid Residence Time 32
Attachment 1.2 Basic Equations and Sketches 33
Attachment 1.3 Gravity Settling Liquid from Vapor Phase 34
Attachment 1.4 Disentraining Vapor from Liquid Phase 35
Attachment 1.5 Vapor/Liquid/Liquid Service 36
Attachment 1.6 Liquid/Liquid Service Only 37
Liquid/Liquid Only Vessels 38
Attachment 1.7 3 FPM Maximum Velocity 39
Attachment 1.8 Drop Leg Dimensions 40
Attachment 1.9 Baffled Separator with Light and Heavy Liquid Ends 41
Attachment 1.10 Baffled Separator with Heavy Liquid End 45
Attachment 2 - Derivation of Equations for Vertical Vessels 48
Attachment 2.1 Liquid Residence time 48
Attachment 2.2 Vapor/Liquid Separation without Mesh Blanket Demisting 49
Attachment 2.3 Vapor/Liquid Separation with Mesh Blanket Demisting 51
Attachment 2.4 Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting 53
Attachment 2.5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting 55
| Attachment 1 - Derivation of Equations for Horizontal Vessels Attachment 1.1 Liquid Residence Time Liquid residence time | Attachment 1 - Derivation of Equations for Horizontal Vessels Attachment 1.1 Liquid Residence Time Liquid residence time |
|---|---|
| Vessel volume = | |
| D Vessel I.D., ft | |
| Vessel volume = 0.785 YD3 0.785 YD3 = | F Percent liquid full L Vessel Tangent length, ft QTL Flow rate of total liquid phase, gpm t Liquid residence time, minutes Y L/D Vessel volume, ft3 |
| (Equation 1) | (Equation 1) |
| = | = |
Attachment 1.2 Basic Equations and Sketches
| Basic Equations and Sketches | Basic Equations and Sketches | Basic Equations and Sketches | Basic Equations and Sketches |
|---|---|---|---|
| Vessel dimensions based on vapor/liquid/liquid separation with drop leg | Vessel dimensions based on vapor/liquid/liquid separation with drop leg | Vessel dimensions based on vapor/liquid/liquid separation with drop leg | Vessel dimensions based on vapor/liquid/liquid separation with drop leg |
Vessel dimension based on liquid/liquid gravity settling | Vessel dimension based on liquid/liquid gravity settling | D Inside diameter, ft DPL O. D. of drop leg, in L Tangent length, ft LDL Length of drop leg, ft VCV Velocity of continuous vapor phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec VTL Velocity of total liquid phase, ft/sec VDTL Velocity of dispersed total liquid phase, ft/sec VDLL Velocity of dispersed light liquid phase, ft/sec VDHL Velocity of dispersed heavy liquid phase, ft/sec VHL Velocity of continuous heavy liquid phase, ft/sec | D Inside diameter, ft DPL O. D. of drop leg, in L Tangent length, ft LDL Length of drop leg, ft VCV Velocity of continuous vapor phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec VTL Velocity of total liquid phase, ft/sec VDTL Velocity of dispersed total liquid phase, ft/sec VDLL Velocity of dispersed light liquid phase, ft/sec VDHL Velocity of dispersed heavy liquid phase, ft/sec VHL Velocity of continuous heavy liquid phase, ft/sec |
| Intermediate Law (Liquid from vapor) | |||
| Stokes Law (Vapor from liquid or dispersed liquid from continuous liquid phase) | |||
| DP Particle diam. of dispersed phase, ft | DP Particle diam. of dispersed phase, ft | DP Particle diam. of dispersed phase, ft | |
| g 32.2 ft/sec2 L Light fluid density, lb/ft3 H Heavy fluid density, lb/ft3 Continuous phase viscosity, lb/ft sec Vt Terminal velocity of particle, ft/sec | g 32.2 ft/sec2 L Light fluid density, lb/ft3 H Heavy fluid density, lb/ft3 Continuous phase viscosity, lb/ft sec Vt Terminal velocity of particle, ft/sec |
Attachment 1.3 Gravity Settling Liquid from Vapor Phase
| Gravity settling liquid from vapor phase | XV Distance top of vessel to maximum liquid level as a fraction of D (see section 4.4) W |
|---|---|
| XVDVCV = WDVDL | Z Fraction of cross-sect. Area corresponding to X (see section 4.4) |
| D Vessel I.D., ft | |
| L Vessel tangent length, ft T Time, minutes | |
| VCV Velocity of continuous vapor phase, ft/sec VDL Velocity of dispersed liquid phase, ft/sec L Liquid density, lb/ft3 | |
| (Intermediate Law) | V Vapor density, lb/ft3 |
| QV Vapor flow rate, ft3/sec | |
| V Vapor viscosity, lb/ft/sec DPL Liquid particle diam., ft (Use 0.00057 ft in the absence of specific process data) | |
Attachment 1.4 Disentraining Vapor from Liquid Phase
| Disentraining vapor from liquid phase | Disentraining vapor from liquid phase |
|---|---|
| XL Distance bottom of vessel to minimum liquid level as a fraction of D (see section 4.4) W | |
| XLDVTL = WDVDV | Z Fraction of cross-sect. area corresponding to X (see section 4.4) |
| VTL Velocity of total liquid phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec QTL Flow rate of total liquid phase, gpm | |
| LL Light liquid viscosity, lb/ft sec | |
| LL Light liquid density, lb/ft3 V Vapor density, lb/ft3 DPV Vapor particle diam., ft (Use 0.00057 ft in the absence of specific process data) | |
| Stokes Law | D Vessel I.D., ft |
| L Vessel tangent length, ft T Time, seconds | |
(Equation 3) | |
Attachment 1.5 Vapor/Liquid/Liquid Service
| Gravity settling heavy liquid phase from light liquid phase in Vapor/Liquid/Liquid service | Gravity settling heavy liquid phase from light liquid phase in Vapor/Liquid/Liquid service |
|---|---|
XLDVTL = WDVHL | XL Distance minimum level to bottom of vessel as a fraction of D (see section 4.4) W |
| Z Fraction of cross-sect. Area corresponding to X (see section 4.4) | |
(Stokes Law) | VTL Velocity of total liquid phase, ft/sec VHL Velocity of heavy liquid phase, ft/sec QTL Flow rate of total liquid phase, gpm LL Light liquid viscosity, lb/ft sec LL Light liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 |
| DPHL Heavy liquid particle diam., ft (Use 0.00041 ft in the absence of specific process data) | |
| D Vessel I.D., ft L Vessel tangent length, ft T Time, seconds | |
| (Equation 4) | |
C values are the same as for disentraining vapor from liquid phase | C values are the same as for disentraining vapor from liquid phase |
Attachment 1.6 Liquid/Liquid Service Only
| Gravity settling heavy liquid phase from light liquid phase in Liquid/Liquid service | Gravity settling heavy liquid phase from light liquid phase in Liquid/Liquid service |
|---|---|
XLLDVTL = WDVDHL | XLL Distance maximum interface level to top of vessel as a fraction of D (see section 4.4) W |
| Z Fraction of cross-sect. Area corresponding to X (see section 4.4) | |
(Stokes Law) | VTL Velocity of total liquid phase, ft/sec VDHL Velocity of heavy liquid phase, ft/sec QTL Flow rate of total liquid phase, gpm LL Light liquid viscosity, lb/ft sec LL Light liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 |
| DPHL Heavy liquid particle diam., ft (Use 0.00041 ft in the absence of specific process data) | |
| D Vessel I.D., ft L Vessel tangent length, ft T Time, seconds | |
| (Equation 4) | |
C values are the same as for disentraining vapor from liquid phase | C values are the same as for disentraining vapor from liquid phase |
Liquid/Liquid Only Vessels
| Gravity settling light liquid phase from heavy liquid phase in Liquid/Liquid service | Gravity settling light liquid phase from heavy liquid phase in Liquid/Liquid service |
|---|---|
XHLDVTL = WDVDLL | XHL Distance minimum interface level to bottom of vessel as a fraction of D (see section 4.4) W |
| Z Fraction of cross-sect. Area corresponding to X (see section 4.4) | |
(Stokes Law) | VTL Velocity of total liquid phase, ft/sec VDLL Velocity of heavy liquid phase, ft/sec QTL Flow rate of total liquid phase, gpm HL Light liquid viscosity, lb/ft sec LL Light liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 |
| DPLL Heavy liquid particle diam., ft (Use 0.00041 ft in the absence of specific process data) | |
| D Vessel I.D., ft L Vessel tangent length, ft T Time, seconds | |
| (Equation 4) | |
C values are the same as for disentraining vapor from liquid phase | C values are the same as for disentraining vapor from liquid phase |
Attachment 1.7 3 FPM Maximum Velocity
3 FPM maximum velocity | |
|---|---|
| D Vessel I.D., ft QTL Flow rate of total liquid phase, gpm | |
| Z Fraction of X-sect. area with liquid (see section 4.4) = 1.0 (liquid full) | |
| D = C(QTL) 1/2 (Equation 5) | |
Attachment 1.8 Drop Leg Dimensions
| Drop leg for disentraining dispersed liquid phase from continuous liquid phase | Drop leg for disentraining dispersed liquid phase from continuous liquid phase |
|---|---|
| QHL Flow rate of continuous phase in drop leg, gpm ADL Cross-sectional area of drop leg, ft2 HL Viscosity of heavy liquid phase, lb/ft sec DDL Drop leg O.D., in DPLL Light liquid particle diameter, ft (Use 0.00041 ft in the absence of specific process data) | |
| LDL Drop leg length, ft | |
| t Time, minutes VDDL Liquid velocity in drop leg, ft/sec | |
| (Equation 6) | |
Length of Drop Leg | |
| (Equation 9) |
Attachment 1.9 Baffled Separator with Light and Heavy Liquid Ends
| Baffled Separator - Vessel dimensions based on vapor/liquid/liquid separation with light and heavy liquid ends | Baffled Separator - Vessel dimensions based on vapor/liquid/liquid separation with light and heavy liquid ends |
|---|---|
| D Inside diameter, ft L Tangent length, ft VCV Velocity of continuous vapor phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec VLL Velocity of continuous light liquid phase, ft/sec VDLL Velocity of dispersed light liquid phase, ft/sec VDTL Velocity of dispersed total liquid, ft/sec VHL Velocity of continuous heavy liquid phase, ft/sec VDHL Velocity of dispersed heavy liquid phase, ft/sec F % liquid full (Typically 80% full) QTL Total liquid flow rate, gpm QLL Flow rate of light liquid phase, gpm QHL Flow rate of heavy liquid phase, gpm t Total liquid Residence time, minute * Heavy Liquid phase baffle clearance, inches | |
| Diameter for residence time - Vessel volume for liquid settling and vapor flow | Diameter for residence time - Vessel volume for liquid settling and vapor flow |
Attachment 1.9 Baffled Separator with Light and Heavy Liquid Ends
| Gravity settling liquid from vapor phase | Gravity settling liquid from vapor phase |
|---|---|
| QV Flow rate of continuous vapor phase, ft3/sec T Time, seconds | |
| 0.25D VCV = 1.5D VDTL | DPL Liquid particle diameter, ft (Use 0.00082 ft in the absence of specific process data) |
| L Liquid density, lb/ft3 V Vapor density, lb/ft3 V Viscosity of vapor, lb/ft sec | |
(Intermediate Law) | |
| (Equation 22) | (Equation 22) |
Attachment 1.9
Baffled Separator with Light and Heavy Liquid Ends
| Disentraining dispersed heavy liquid phase from light liquid phase | Disentraining dispersed heavy liquid phase from light liquid phase |
|---|---|
| VDHL = VLL | DPHL Heavy liquid particle diameter, ft (Use 0.00041 ft in the absence of specific process data) |
| LL Light liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 LL Viscosity of light liquid, lb/ft sec | |
(Stokes Law) | |
| (Equation 24) | |
Attachment 1.9
Baffled Separator with Light and Heavy Liquid Ends
| Disentraining dispersed light liquid phase from heavy liquid phase | Disentraining dispersed light liquid phase from heavy liquid phase |
|---|---|
| DPLL Light liquid particle diameter, ft (Use 0.00041 ft in the absence of specific process data) | |
| HL Viscosity of heavy liquid, lb/ft sec | |
(Stokes Law) | |
| (Equation 23) |
Attachment 1.10 Baffled Separator with Heavy Liquid End
| Baffled Separator - Vessel dimensions based on vapor/liquid/liquid separation with heavy liquid end. | Baffled Separator - Vessel dimensions based on vapor/liquid/liquid separation with heavy liquid end. |
|---|---|
| D Inside diameter, ft L Tangent length, ft VCV Velocity of continuous vapor phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec VTL Velocity of total liquid phase, ft/sec VDL Velocity of dispersed liquid phase, ft/sec VDLL Velocity of dispersed light liquid phase, ft/sec * Heavy Liquid phase baffle clearance, inches | |
| Residence time - Vessel volume for liquid settling and vapor flow | Residence time - Vessel volume for liquid settling and vapor flow |
| F % liquid Full QTL Total liquid flow rate, gpm QLL Flow rate of light liquid phase, gpm | |
| QHL Flow rate of heavy liquid phase, gpm | |
| t Residence time, minutes Vessel volume, ft3 | |
| (Equation 16) | |
| Gravity settling liquid from vapor phase | Gravity settling liquid from vapor phase |
| QV Flow rate of continuous vapor phase, ft3/sec | |
| 1.4 DVDL = 0.25 DVCV | T Time, seconds |
Attachment 1.10
Baffled Separator with Heavy Liquid End
| Gravy settling liquid from vapor phase | Gravy settling liquid from vapor phase |
|---|---|
(Intermediate Law) | DPL Liquid particle diameter, ft (Use 0.00082 ft in the absence of specific process data) PL Liquid density, lb/ft3 |
| P Vapor density, lb/ft3 | |
| Viscosity of vapor lb/ft sec | |
| Disentraining vapor from liquid phase | Disentraining vapor from liquid phase |
| DPV Vapor particle diameter, ft (Use 0.00057 ft in the absence of specific process data) PLL Light liquid density, lb/ft3 | |
| Viscosity of light liquid, lb/ft sec | |
(Stokes Law) | |
| (Equation 18) |
Attachment 1.10
Baffled Separator with Heavy Liquid End
| Liquid/liquid gravity settling | Liquid/liquid gravity settling |
|---|---|
| DPLL Light liquid particle diameter, ft (Use 0.00041 ft in the absence of specific process data) PHL Heavy liquid density, lb/ft3 | |
| Viscosity of heavy liquid, lb/ft sec | |
(Stokes Law) | |
| (Equation 19) | |
Attachment 2 - Derivation of Equations for Vertical Vessels
| Attachment 2.1 Liquid Residence time | Attachment 2.1 Liquid Residence time |
|---|---|
| Liquid residence time | |
| D Vessel I.D., ft F Percent liquid full | |
| L Vessel tangent length, ft | |
| QTL Flow rate of total liquid phase, gpm t Liquid residence time, minutes | |
| Y L/D | |
| Vessel volume, ft3 | |
| Equation 27) | |
Attachment 2.2 Vapor/Liquid Separation without Mesh Blanket Demisting
| Vapor/Liquid Separation without Mesh Blanket Demisting | Vapor/Liquid Separation without Mesh Blanket Demisting |
|---|---|
| D I.D. of vessel, ft L Tangent length, ft DIN Nominal pipe diameter of inlet, in Diameter for gravity settling liquid from vapor phase Intermediate Law: VDL Terminal velocity of particle, ft/sec g 32.2 ft/sec2 DPL Particle diameter, ft PL Liquid density, lb/ft3 Pv Vapor density, lb/ft3 v Vapor viscosity, lb/ft sec | |
| VCV Velocity of continuous vapor phase, ft/sec QV Flow rate of continuous vapor phase, ft3/sec A Vessel cross-sectional area, ft2 VDL Velocity of dispersed liquid phase, ft/sec DPL Liquid particle diameter, ft | |
| (Equation 28) | |
| Attachment 2.2 | Attachment 2.2 |
| Vapor/Liquid Separation without Mesh Blanket Demisting | Vapor/Liquid Separation without Mesh Blanket Demisting |
| Disentraining vapor from liquid phase | Disentraining vapor from liquid phase |
| Stokes Law: | |
| VDV Terminal velocity of particle, ft/sec g 32.2 ft/sec2 DPV Particle diameter, ft PL Liquid density, lb/ft3 PH Heavy phase density, lb/ft3 L Continuous phase viscosity, lb/ft sec A Vessel cross-sectional area, ft2 QTL Flow rate of continuous liquid phase, gpm | |
| Vapor density, lb/ft3 | |
| L Liquid density, lb/ft3 VCL Velocity of continuous liquid phase, ft/sec | |
| VDV Velocity of dispersed vapor phase, ft/sec | |
| DPV Vapor particle diameter, ft | |
Attachment 2.3 Vapor/Liquid Separation with Mesh Blanket Demisting
| Vapor/Liquid Separation with Mesh Blanket Demisting | Vapor/Liquid Separation with Mesh Blanket Demisting | |
| D I.D. of vessel, ft DB Diameter of mesh blanket, ft L Tangent length, ft DIN Nominal pipe diameter of inlet, in VCV Velocity of continuous vapor phase, ft/sec VDL Velocity of dispersed liquid phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec VCL Velocity of continuous liquid phase, ft/sec QV Flow rate of continuous vapor phase, ft3/sec QTL Flow rate of continuous liquid phase, gpm g 32.2 ft/sec2 DPV Vapor particle diameter, ft DPL Liquid particle diameter, ft L Liquid density, lb/ft3 V Vapor density, lb/ft3 V Vapor viscosity, lb/ft sec L Liquid viscosity, lb/ft sec K Pressure coefficient S Support coefficient | D I.D. of vessel, ft DB Diameter of mesh blanket, ft L Tangent length, ft DIN Nominal pipe diameter of inlet, in VCV Velocity of continuous vapor phase, ft/sec VDL Velocity of dispersed liquid phase, ft/sec VDV Velocity of dispersed vapor phase, ft/sec VCL Velocity of continuous liquid phase, ft/sec QV Flow rate of continuous vapor phase, ft3/sec QTL Flow rate of continuous liquid phase, gpm g 32.2 ft/sec2 DPV Vapor particle diameter, ft DPL Liquid particle diameter, ft L Liquid density, lb/ft3 V Vapor density, lb/ft3 V Vapor viscosity, lb/ft sec L Liquid viscosity, lb/ft sec K Pressure coefficient S Support coefficient | |
| Equation 30: | Equation 30: | Equation 30: |
| Equation 31: | ||
Attachment 2.3
Vapor/Liquid Separation with Mesh Blanket Demisting
| Equation 32 | ||
|---|---|---|
| For top flanged head (DV 2’-6”) | ||
| (For one-piece blanket supported by X-bar grid) (See page 22 for values for S & K) | ||
| For top ellipsoidal head (DV 2’-6”) + S | For top ellipsoidal head (DV 2’-6”) + S | (See page 22 for values for S & K) |
| Style “A” should be applied as the default mesh blanket style. Style “G” is no longer used by Inflection Point Engineering for new unit designs. Equation 33a. If DB + 0.66 < D, then use a partial mesh blanket. Equation 33b. DB + 0.66 ≥ D, then Set D=DB and use a full mesh blanket. If DB is not an even 6” (100) interval, round of to next larger 6” (100) interval. | Style “A” should be applied as the default mesh blanket style. Style “G” is no longer used by Inflection Point Engineering for new unit designs. Equation 33a. If DB + 0.66 < D, then use a partial mesh blanket. Equation 33b. DB + 0.66 ≥ D, then Set D=DB and use a full mesh blanket. If DB is not an even 6” (100) interval, round of to next larger 6” (100) interval. | Style “A” should be applied as the default mesh blanket style. Style “G” is no longer used by Inflection Point Engineering for new unit designs. Equation 33a. If DB + 0.66 < D, then use a partial mesh blanket. Equation 33b. DB + 0.66 ≥ D, then Set D=DB and use a full mesh blanket. If DB is not an even 6” (100) interval, round of to next larger 6” (100) interval. |
Attachment 2.4 Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting
| Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting | Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting | Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting | Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting |
|---|---|---|---|
| D I.D. of vessel, ft L Tangent length, ft DIN Nominal pipe diameter of inlet, in DON Nominal pipe diameter of outlet, in VCV Velocity of continuous vapor phase, ft/sec VDL Velocity of dispersed liquid in vapor phase, ft/sec VDV Velocity of dispersed vapor in liquid phase, ft/sec VTL Velocity of total liquid phase, ft/sec VHL Velocity of dispersed liquid in total liquid phase, ft/sec VCL Velocity of continuous liquid phase, ft/sec V Vapor viscosity, lb/ft sec LL Light liquid viscosity, lb/ft sec QTL Flow rate of total liquid phase, gpm V Density of vapor, lb/ft3 L Density of liquid, lb/ft3 | D I.D. of vessel, ft L Tangent length, ft DIN Nominal pipe diameter of inlet, in DON Nominal pipe diameter of outlet, in VCV Velocity of continuous vapor phase, ft/sec VDL Velocity of dispersed liquid in vapor phase, ft/sec VDV Velocity of dispersed vapor in liquid phase, ft/sec VTL Velocity of total liquid phase, ft/sec VHL Velocity of dispersed liquid in total liquid phase, ft/sec VCL Velocity of continuous liquid phase, ft/sec V Vapor viscosity, lb/ft sec LL Light liquid viscosity, lb/ft sec QTL Flow rate of total liquid phase, gpm V Density of vapor, lb/ft3 L Density of liquid, lb/ft3 | ||
| Diameter for gravity settling liquid from vapor phase | Diameter for gravity settling liquid from vapor phase | Diameter for gravity settling liquid from vapor phase | Diameter for gravity settling liquid from vapor phase |
| (Same as for vapor/liquid separation. See page 39) (Equation 34) | (Same as for vapor/liquid separation. See page 39) (Equation 34) | (Same as for vapor/liquid separation. See page 39) (Equation 34) | (Same as for vapor/liquid separation. See page 39) (Equation 34) |
| Area for disentraining vapor from liquid phase | Area for disentraining vapor from liquid phase | Area for disentraining vapor from liquid phase | Area for disentraining vapor from liquid phase |
| (Oversize by 10% for structural supports | (Oversize by 10% for structural supports | DPV = Vapor particle diameter, ft | |
| (See Liquid/Vapor Separation) | (See Liquid/Vapor Separation) | (See Liquid/Vapor Separation) | (See Liquid/Vapor Separation) |
Attachment 2.4
Vapor/Liquid/Liquid Separation without Mesh Blanket Demisting
| Area for gravity settling dispersed liquid phase from continuous liquid phase: | Area for gravity settling dispersed liquid phase from continuous liquid phase: |
|---|---|
| (Oversize area by 10% for structural support) DPV Vapor particle diameter, ft DPHL Dispersed liquid particle diameter, ft PHL Density of dispersed heavy liquid phase, lb/ft3 | |
| PLL Density of continuous light liquid phase, lb/ft3 | |
| Diameter for disentraining vapor from liquid phase and dispersed liquid from continuous liquid phase: | Diameter for disentraining vapor from liquid phase and dispersed liquid from continuous liquid phase: |
| Dimensions: | |
| For = D x C2 | (With C1 enter table of circular segmental functions (handbook) and obtain chord height/ diameter value, C2. |
| For = D - 1 | |
Attachment 2.5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting
| Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting | Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting |
|---|---|
| D I.D. of vessel, ft DB Diameter of mesh blanket, ft L Tangent length, ft DIN Nominal pipe diameter of inlet, in DON Nominal pipe diameter of outlet, in VCV Velocity of continuous vapor phase, ft/sec VDL Velocity of dispersed liquid in vapor phase, ft/sec VDV Velocity of dispersed vapor in liquid phase, ft/sec VTL Velocity of total liquid phase, ft/sec VLD Velocity of dispersed liquid in total liquid phase, ft/sec VCL Velocity of continuous liquid phase, ft/sec QTL Flow rate of total liquid phase, gpm QV Flow rate of vapor phase, ft3/sec V Density of vapor, lb/ft3 L Density of liquid, lb/ft3 HL Density of dispersed heavy liquid phase lb/ft3 LL Density of continuous light liquid phase lb/ft3 DPV Vapor particle diameter, ft DPL Dispersed liquid particle diameter, ft DPHL Dispersed heavy liquid particle diameter, ft | |
| V Vapor viscosity, lb/ft sec LL Light liquid viscosity, lb/ft sec K Pressure coefficient | |
| S Support coefficient | |
| (Equation 30) | (Equation 35) |
| Attachment 2.5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting | Attachment 2.5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting | Attachment 2.5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting |
|---|---|---|
| For Top Flanged Head | For Top Flanged Head | |
| (See page 22 for values for S & K) | (See page 22 for values for S & K) | (See page 22 for values for S & K) |
| For Top Ellipsoidal Head | For Top Ellipsoidal Head | |
| + S | (See page 22 for values for S & K) | (See page 22 for values for S & K) |
| Style “A” should be applied as the default mesh blanket style. Style “G” is no longer used by Inflection Point Engineering for new unit designs. (Equation 33a) If DB + 0.66<D, then use a partial mesh blanket. (Equation 33b) If DB + 0.66 ≥ D, then Set D=DB + 0.66 and use a full mesh blanket. If D is not an even 6” (100) interval, round off to next larger 6” (100) interval. Note: Vessel diameter (D) must be equal to or larger than diameters from equations on pages 44 and 45. | Style “A” should be applied as the default mesh blanket style. Style “G” is no longer used by Inflection Point Engineering for new unit designs. (Equation 33a) If DB + 0.66<D, then use a partial mesh blanket. (Equation 33b) If DB + 0.66 ≥ D, then Set D=DB + 0.66 and use a full mesh blanket. If D is not an even 6” (100) interval, round off to next larger 6” (100) interval. Note: Vessel diameter (D) must be equal to or larger than diameters from equations on pages 44 and 45. | Style “A” should be applied as the default mesh blanket style. Style “G” is no longer used by Inflection Point Engineering for new unit designs. (Equation 33a) If DB + 0.66<D, then use a partial mesh blanket. (Equation 33b) If DB + 0.66 ≥ D, then Set D=DB + 0.66 and use a full mesh blanket. If D is not an even 6” (100) interval, round off to next larger 6” (100) interval. Note: Vessel diameter (D) must be equal to or larger than diameters from equations on pages 44 and 45. |
Attachments
IPE-TM-300-04 Vessel Sizing Guidelines
Purpose
This procedure covers the guidelines for sizing most of the vessels used in Inflection Point Engineering process units for phase separation, mixing, and pressurized liquid surge and storage. Use the Attachments for reference only. WIN254, the Inflection Point Engineering Vessel Program, uses the equations outlined in this document.
Contents
Section Page No.
1. Purpose 1
2. Contents 1
3. Sizing Considerations 2
3.1 Vessel Configuration 2
3.2 Residence Time 4
3.3 Surge Time 5
3.4 Phase Separation 5
3.5 Fluidizing 6
4. Guidelines for Sizing Horizontal Vessels 9
4.1 Vessel Shell 9
4.2 Vessel Drop Leg 10
4.4 Normal Level/Cross - Sectional Area/Residence Time Relationships 20
5. Guidelines for Sizing Vertical Vessels 21
5.1 Surge/Storage Vessels 21
5.2 Phase Separation Vessels Without Mist Eliminator 21
5.3 Phase Separation Vessels With Mist Eliminator 22
5.4 Vertical Vessel Dimensions 23
Figure 2 Vapor/Liquid Separation 23
Figure 3 Vapor/Liquid Separation with Mist Eliminator Demisting 24
Figure 4 Vapor/Liquid/Liquid Separation 26
Figure 5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting 28
Figure 6 Surge with Liquid/Liquid Separation 29
3. Sizing Considerations
3.1 Vessel Configuration
The selection of a vessel configuration shall consider space restrictions, economics and the following process requirements:
a. For a service with a high vapor rate, a low liquid rate and only one liquid phase, a vertical vessel is the most suitable to make efficient use of the cross-sectional area for vapor flow. WIN254 Service Type = Separator or Surge.
b. For a service with a low vapor rate, a high liquid rate and only one liquid phase, either a vertical or horizontal vessel is suitable although the horizontal vessel is usually preferred for ease of phase separation. WIN254 Service Type = Receiver or Separator.
A horizontal vessel is also the preferred configuration for services that contain a second liquid phase on start-up only. WIN254 Service Type = Separator or Surge.
c. For a service with two liquid phases and no vapor phase (Liquid/Liquid service), a horizontal vessel is the most suitable for ease of separation of the liquid phases. This vessel operates liquid full; NLL = 100%. The designer must specify the location of the Normal Interface Level (NIL) between the light and heavy liquid. WIN254 Service Type = Receiver, Separator, Settler or Mixer.
d. For a service with a vapor phase and two liquid phases (Vapor/Liquid/Liquid Service) where the heavy liquid phase rate is small compared to the light liquid phase rate, a horizontal vessel with a drop leg is the most suitable. WIN254 Service Type = Receiver or Separator.
e. For a service with a vapor phase and two liquid phases where the light liquid phase rate is small compared to the heavy liquid phase rate, a horizontal vessel with a baffled outlet end for the heavy liquid phase is the most suitable. WIN254 Service Type = Separator, Internals BP - Hvy Liq. Separate Ends.
f. For a service with a vapor phase and two liquid phases where the liquid phase rates are approximately equal, a horizontal vessel with a baffled outlet end for each of the liquid phases is the most suitable. WIN254 Service Type = Separator, Internals BP – Lgt/Hvy Liq. Separate Ends.
g. For horizontal vessels, determine the tangent length/diameter (L/D) ratios. The L/D ratio of 3 is the most commonly used ratio.
3.2 Residence Time
In this procedure residence time is defined as the amount of time required to displace the liquid inventory of the vessel from it’s NLL to empty at normal liquid flow rate. For simplicity, the head volume is not included in the residence time hand calculations (head volume is considered in the WIN254 calculations). The determination of a residence time for the liquid phase shall consider the following factors:
a. The recommendation of the Process Specialist based on experience with the process.
b. The effects of loss of level or over filling on upstream or downstream equipment.
c. The difficulty in separating phases. Fluid properties, emulsifying or foaming tendencies, upstream mixing, surface active agents and suspended solids can affect phase separation in varying degrees.
Common residence times used for sizing vessels are as follows:
d. For a horizontal vessel with a vapor phase and one liquid phase, use 5 minutes, 1/2 full, based on the liquid phase rate.
e. For a horizontal vessel with a vapor phase and two liquid phases, use 10 minutes, 1/2 full, based on the total liquid phase rate. When the difference in densities of the liquid phases is low (7 lb/ft3 or less) and/or the lighter liquid viscosity is high (1 centipoise or more) 30 minutes or more may be necessary. When the difference in densities of the liquid phases is high (14 lb/ft3 or more), 5 minutes may be adequate.
f. Feed Surge Drum residence times may vary over a wide range, typically 15 – 30 minutes. 15 minutes should be used as a minimum. Consult with the appropriate technology specialist to determine if a different residence time should be applied.
g. For drop legs with a level controlled outlet, use 5 to 10 minutes as the range for the drop leg capacity.
h. For drop legs with a manually controlled outlet, use 600 minutes of drop leg capacity for one draining during an eight hour shift. Reference Procedure
3.3 Surge Time
Liquid surge time is the amount of time required to change the liquid level from one extreme of the level controller to the other (0-100%). For liquid surge time from high to low level, use 2 to 4 minutes for most conditions.
- For vertical separators upstream of compressors or other critical equipment, provide a minimum of 18” (450) or 2 minutes surge time between the bottom of the inlet nozzle and the maximum controlled level (HLL).
- For horizontal vessels, consider the location of the normal liquid level. If the vapor rate is small and the liquid rate is large, it may be advantageous to set the normal liquid level above the vessel center line to maximize the liquid residence volume. Conversely, if the vapor rate is large and the liquid rate is small, it may be advantageous to set the normal liquid level below the vessel center line to maximize the volume for vapor flow.
3.4 Phase Separation
Designing for phase separation assumes that a particle falling under the influence of gravity will accelerate until the frictional drag force balances the gravitational force. The particle then falls at a constant velocity which is defined as the terminal or free settling velocity. There are three laws for determining the terminal velocity which is the basis of criteria for sizing vessels for phase separation. These laws have limits based on the particle Reynolds number as follows:
| Particle Reynolds Number | Law |
|---|---|
| <2 | Stoke’s |
| 2 to <500 | Intermediate |
| 500 to <200,000 | ’s |
Design conditions for receivers, separators and drums fall into the categories of the Stoke’s and Intermediate Laws. Use Stoke’s Law for disentraining vapor from the liquid phase and gravity settling the dispersed liquid phase from the continuous liquid phase, and use the Intermediate Law for gravity settling liquid from the vapor phase. The particle size or diameter used in these laws is often difficult to determine. In selecting the particle diameter, consider the effect of entrainment on downstream equipment, effluent quality and overall economics.
Use the following particle diameters in these guidelines in lieu of more definitive sizes:
250 microns (0.00082 ft) for gravity settling liquid from the vapor phase.
175 microns (0.00057 ft) for disentraining vapor from the liquid phase.
125 microns (0.00041 ft) for gravity settling the dispersed liquid phase from the continuous liquid phase.
3.5 Fluidizing
Process fluids in vertical upflow vessels have the potential to fluidize any bed material contained in the vessel. Inflection Point Engineering typically provides a layer of ¼ inch and ¾ inch alumina balls to help hold down the bed and prevent any disturbance to the top of the bed by localized flow patterns.
The typical velocities encountered in new Inflection Point Engineering designed vessels are significantly short of those required to fluidize a packed bed. A revamp of a vessel, in which the capacity of the unit is often being pushed for maximum throughput increase could potentially fluidize a packed bed. The Design Engineer should calculate the fluidizing velocity to ensure that the bed material cannot be fluidized under any expected operating condition (including rated flow or flow rates encountered during special procedures, such as regeneration, sulfur stripping, etc.).
Four equations are used to calculate the fluidizing velocity. Only one of the four equations is applied, depending on the bulk fluid velocity. These equations, listed below, are “Stokes Law”, “Intermediate Law”, “’s Law” and a “Trial & Error“ solution.
Stokes Law: ut = gDp2(p-)/18
Intermediate Law: ut = 0.153g0.71Dp1.14(p-)0.71/ 0.43
’s Law: ut = 1.74 [gDp(p-)/]1/2
Trial & Error: ut = [g(p-)pDp)/3CDused with Figure 7-3 and NRE = Dpuo/
The “K” value associated with the flow rate must be calculated as noted below to be able to determine the flow range and the corresponding fluidizing equation.
The equation for calculating “K” is K = Dp[g(p-)/2]1/3.
Once “K” has been calculated, the appropriate fluidizing equation can be selected, based on the following criteria:
A) If K<3.3, Stokes law is applied
B) If 3.3<K<43.6, the Intermediate law is applied
C) If 43.6<K<2360, ’s law is applied
D) If K>2360, the “Trial & Error” solution must be applied.
The trial & error solution to determine the fluidizing velocity is applied as noted below:
1) Assume a value for ut.
2) Calculate the Reynolds Number based on the assumed ut.
3) Using the calculated Reynolds Number, determine CD from Figure
7-3 (use the spheres line)
4) Substitute the value of CD into the trial & error equation listed above, then calculate ut.
5) Repeat steps 1-4, using the calculated ut to obtain a new Reynolds Number.
6) Continue repeating steps 1-4 until ut-assumed = ut-calculated.
Once the fluidizing velocity has been determined from equations A-D listed above, it should be compared to the actual velocities expected under all operations (including regeneration, etc.). If the actual velocity for any operating case is greater than the fluidizing velocity, increase the vessel diameter until the actual velocity is reduced below the fluidizing velocity. The target velocity should be less than 90% of the fluidizing velocity.
Abbreviations
G - gravitational constant, 32.2 ft/sec
Dp - particle diameter, feet
p - particle density, lb/ft3
- fluid density, lb/ft3
, t - fluid viscosity, lb/(ft-sec)
Cd - Drag Coefficient, from Figure 7-3
Figure 1 – Drag Coefficients
4. Guidelines for Sizing Horizontal Vessels
The equations in Section 4.3 are the basis for WIN254, “Horizontal Vessels”.
4.1 Vessel Shell
a. Determine the tangent length/diameter (L/D) ratio. Typical L/D ratios for Baffled Separators is 3.5 - 3.6. all other vessels typically begin the design using an L/D of 3.0.
b. Determine the surge time or liquid residence time and percent liquid full.
Note that for liquid full vessels NLL = 100% full. If there is an interface between light and heavy liquids, the designer must determine the Normal Interface Level (NIL) as a percentage of total volume; NIL<100%.
c.1 Determine the normal liquid level (NLL) for vessels less than liquid full. Reference Figures 1A-1E, “ Level/Cross-Sectional Area/Residence Time Relationships” for NLL locations and related cross-sectional areas, allowable level ranges and residence times. Select a standard level control range as close as possible to the allowable level range indicated in Figures 1A-1E, for the NLL used for design. It may be necessary to vary the L/D ratio in order to approximate the allowable level range with a standard level control range.
c.2 Determine the normal interface level (NIL) for liquid full vessels. Reference Figures 1A-1E, “ Level/Cross-Sectional Area/Residence Time Relationships” for NIL locations and related cross-sectional areas, allowable level ranges and residence times. Select a standard level control range as close as possible to the allowable level range indicated in Figures 1A-1E, for the NIL used for design. It may be necessary to vary the L/D ratio in order to approximate the allowable level range with a standard level control range.
d. Calculate the vessel diameter to satisfy the residence time requirement by using equation 1. WIN254 calculates, but does not size the vessel based on residence time. If the vessel is to be sizwed based on residence time, the designer must manually enter into WIN254 the tangent length & diameter suggested by WIN254.
e. If vapor/liquid/liquid phase separations are required except for baffled separators, calculate the diameters for the necessary phase separations by using the appropriate equations 2, 3, 4 and 10.
f. If baffled separators are required, calculate the diameters for the necessary phase separations from the appropriate equations 11 to 25.
g. If a vertical coalescer (reference Attachment 1.2, “Basic Equations and Sketches”) is to be installed in the vessel, calculate the coalscer diameter necessary for a maximum liquid velocity of 3 ft/minute by using equation 5. The clearance between the coalscer and the drop leg is expected to be approximately one-half of the vessel diameter.
h. Size the vessel on the basis of the largest of the preceding calculated diameters. If a horizontal mist eliminator (see Attachment 1.2) is to be installed in the vessel, calculate the vessel diameter necessary to accommodate the mist eliminator by using equation 26. If the diameter required for the mesh blanket is larger than the largest of the preceding calculated diameters, use it for the design of the vessel, but use the allowable level range based on the largest of the preceding calculated diameters. This will ensure sufficient space for vapor flow between the bottom of the mist eliminator and the maximum liquid level.
When the vessel must accommodate slugs of water, raise the vortex breaker to provide volume in the lower part of the vessel in addition to the drop leg for the water surge.
i. Round off diameters and tangent lengths in English units to the next larger 6 inch increment if the diameters are not already in even 6-inch increments. Round off diameter and tangent lengths in metric units to the next larger 100 millimeter increment if the dimensions are not already in even 100 millimeter increments.
4.2 Vessel Drop Leg
- Calculate the drop leg diameter for phase separation by using equation 6.
- If the Process Specialist has recommended a maximum drop leg velocity, calculate the drop leg diameter by using that maximum velocity. See equation 7.
- Determine the residence time.
- Calculate the drop leg diameter based on the residence time and a drop leg length of 3.5 feet (1070 mm). See equation 8.
- If the largest of the preceding calculated drop leg diameters (equations 6, 7 & 8) is less than one-half of the vessel diameter, round this diameter to the next larger whole even inch increment to match pipe diameters. If the largest of the preceding calculated drop leg diameters is equal to or larger than one-half of the vessel diameter, round one-half of the vessel diameter down to the next lower whole even inch increment and increase the drop leg length beyond 3.5 feet (1070 mm) to satisfy the residence time requirement and round the length to the next largest 3 inch (100 mm) increment. See equation 9. If the drop leg length becomes larger than 6 feet (1800 mm), consider a smaller residence time or a different vessel configuration, such as a baffled separator.
Specify drop leg diameters <= 24” as O.D. (outside diameter). Drop legs greater than 24” should be specified as ID, as pipe sizes typically are not available in diameters greater than 24”. The minimum drop leg O.D. is 14 inches (360 mm). The minimum drop leg length is 3.5 feet (1100 mm).
4.3 Horizontal Vessel Dimensions
V/L or V/L/L Separations - Applied when VLL>VHL
WIN254 Service Type = Receiver or Separator.
| 1. Liquid residence time 2. Gravity settling liquid from vapor phase | C Coefficient, see equations this page D , ft DDL Drop leg O.D. in DPL Liquid particle diameter, ft *(0.00082 ft) DPLL Light liquid particle diameter, ft *(0.00041 ft) DPHL Heavy liquid particle diameter, ft *(0.00041 ft) DPV Vapor particle diameter, ft *(0.00057 ft) F Volume Percent liquid full FLER Volume Percent liquid full of Light Ends Resrvoir FHER Volume Percent liquid full of Heavy Ends Resrvoir g 32.2 ft/sec2 L Vessel tangent length, ft LDL Drop leg length, ft L/D Ratio of Vessel Length/Diameter QV Flow rate of vapor phase, ft3/sec QLL Flow rate of light liquid phase, gpm QHL Flow rate of heavy liquid phase, gpm QTL Flow rate of total liquid phase, gpm | C Coefficient, see equations this page D , ft DDL Drop leg O.D. in DPL Liquid particle diameter, ft *(0.00082 ft) DPLL Light liquid particle diameter, ft *(0.00041 ft) DPHL Heavy liquid particle diameter, ft *(0.00041 ft) DPV Vapor particle diameter, ft *(0.00057 ft) F Volume Percent liquid full FLER Volume Percent liquid full of Light Ends Resrvoir FHER Volume Percent liquid full of Heavy Ends Resrvoir g 32.2 ft/sec2 L Vessel tangent length, ft LDL Drop leg length, ft L/D Ratio of Vessel Length/Diameter QV Flow rate of vapor phase, ft3/sec QLL Flow rate of light liquid phase, gpm QHL Flow rate of heavy liquid phase, gpm QTL Flow rate of total liquid phase, gpm |
3. Disentraining vapor from liquid phase 4. Gravity settling heavy liquid phase from light liquid phase | t Liquid residence time, minutes tLER Liquid residence time, minutes of Light Ends Resrvoir tHER Liquid residence time, minutes of Heavy Ends Resrvoir VDL Liquid velocity in drop leg, ft/min V Vapor density, lb/ft3 L Liquid density, lb/ft3 LL Light liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 V Vapor viscosity, lb/ft sec LL Viscosity of light liquid phase, lb/ft sec HL Viscosity of heavy liquid phase, lb/ft sec * Use in the absence of specific process data Note: Flowing data are at operating conditions XV Distance from HLL to top of vessel expressed as a fraction of “D” XL Distance from LLL to bottom of vessel expressed as a fraction of “D” CSAV Cross Sectional Area associated with XV, expressed as a fraction of the total vessel cross sectional area (see figure 1) CSAL Cross Sectional Area associated with XL, expressed as a fraction of the total vessel cross sectional area (see figure 1) XLL Distance from HIL to top of vessel expressed as a fraction of “D” XHL Distance from LIL to bottom of vessel expressed as a fraction of “D” CSALL Cross Sectional Area associated with XLL, expressed as a fraction of the total vessel cross sectional area (see figure 1) CSAHL Cross Sectional Area associated with XHL, expressed as a fraction of the total vessel cross sectional area (see figure 1) | t Liquid residence time, minutes tLER Liquid residence time, minutes of Light Ends Resrvoir tHER Liquid residence time, minutes of Heavy Ends Resrvoir VDL Liquid velocity in drop leg, ft/min V Vapor density, lb/ft3 L Liquid density, lb/ft3 LL Light liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 V Vapor viscosity, lb/ft sec LL Viscosity of light liquid phase, lb/ft sec HL Viscosity of heavy liquid phase, lb/ft sec * Use in the absence of specific process data Note: Flowing data are at operating conditions XV Distance from HLL to top of vessel expressed as a fraction of “D” XL Distance from LLL to bottom of vessel expressed as a fraction of “D” CSAV Cross Sectional Area associated with XV, expressed as a fraction of the total vessel cross sectional area (see figure 1) CSAL Cross Sectional Area associated with XL, expressed as a fraction of the total vessel cross sectional area (see figure 1) XLL Distance from HIL to top of vessel expressed as a fraction of “D” XHL Distance from LIL to bottom of vessel expressed as a fraction of “D” CSALL Cross Sectional Area associated with XLL, expressed as a fraction of the total vessel cross sectional area (see figure 1) CSAHL Cross Sectional Area associated with XHL, expressed as a fraction of the total vessel cross sectional area (see figure 1) |
5. 3 ft/min maximum velocity of total liquid phase 6. Disentraining dispersed liquid phase from continuous liquid phase in drop leg 7. Maximum velocity for drop leg | 5. 3 ft/min maximum velocity of total liquid phase 6. Disentraining dispersed liquid phase from continuous liquid phase in drop leg 7. Maximum velocity for drop leg | 5. 3 ft/min maximum velocity of total liquid phase 6. Disentraining dispersed liquid phase from continuous liquid phase in drop leg 7. Maximum velocity for drop leg |
8. Tangent Length for drop leg liquid residence time | 8. Tangent Length for drop leg liquid residence time | 8. Tangent Length for drop leg liquid residence time |
9. Diameter for drop leg liquid residence time Note: DDL calculated in equation 9 must be larger than DDL calculated in equations 6 & 7. Diameters smaller than those calculated in equations 6 & 7 will notr provide the required separation or cause the velocity in the drop leg to exceed the maximum target identified in equation 7. | 9. Diameter for drop leg liquid residence time Note: DDL calculated in equation 9 must be larger than DDL calculated in equations 6 & 7. Diameters smaller than those calculated in equations 6 & 7 will notr provide the required separation or cause the velocity in the drop leg to exceed the maximum target identified in equation 7. | |
| L/L Separations Applied when vapor (process gas or blanketing gas) is not present WIN254 Service Type = Settler ( Do not use Separator or Receiver for this service). 1. Liquid residence time 5. 3 ft/min maximum velocity of total liquid phase 10.a. Gravity settling heavy liquid phase from light liquid phase 10.b. Gravity settling light liquid phase from heavy liquid phase | L/L Separations Applied when vapor (process gas or blanketing gas) is not present WIN254 Service Type = Settler ( Do not use Separator or Receiver for this service). 1. Liquid residence time 5. 3 ft/min maximum velocity of total liquid phase 10.a. Gravity settling heavy liquid phase from light liquid phase 10.b. Gravity settling light liquid phase from heavy liquid phase | L/L Separations Applied when vapor (process gas or blanketing gas) is not present WIN254 Service Type = Settler ( Do not use Separator or Receiver for this service). 1. Liquid residence time 5. 3 ft/min maximum velocity of total liquid phase 10.a. Gravity settling heavy liquid phase from light liquid phase 10.b. Gravity settling light liquid phase from heavy liquid phase |
Baffled Separators - Dry End WIN254 Service Type = Separator, Internals BP – Dry Ends. 11. Residence time |
|---|
| 12. Gravity settling liquid from vapor phase |
13. Disentraining vapor from liquid phase |
14. Gravity settling heavy liquid phase from light liquid phase |
15. Tangent length |
Baffled Separators - Heavy Liquid End WIN254 Service Type = Separator, Internals BP - Hvy Liq. Separate Ends. 16. Residence Time | ||||
|---|---|---|---|---|
17. Gravity settling liquid from vapor phase | 17. Gravity settling liquid from vapor phase | 17. Gravity settling liquid from vapor phase | ||
| 18. Disentraining vapor from liquid phase | 18. Disentraining vapor from liquid phase | 18. Disentraining vapor from liquid phase | ||
| 19. Liquid/Liquid gravity setting 20. Tangent Length L = 3.5 D | 19. Liquid/Liquid gravity setting 20. Tangent Length L = 3.5 D | |||
| Baffled Separators - Light and Heavy Liquid Ends WIN254 Service Type = Separator, Internals BP – Lgt/Hvy Liq. Separate Ends. Residence Time | |||
|---|---|---|---|
Disentraining liquid from vapor phase | |||
Disentraining vapor from liquid phase | |||
| Disentraining heavy liquid from light liquid phase Tangent length L = 3.6 D | Disentraining heavy liquid from light liquid phase Tangent length L = 3.6 D | ||
| Horizontal Mist Eliminator 26. Horizontal Mist Eliminator Side of a square Mist Eliminator = K-Values Conventional Mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.17 15 psig 0.35 1” Hg 0.17 50 psig 0.34 5” Hg 0.23 100 psig 0.32 10” Hg 0.28 200 psig 0.31 20” Hg 0.32 300 psig 0.30 30” Hg 0.35 500 psig 0.28 ≥1000 psig 0.27 Multi-Zone mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.14 15 psig 0.28 1” Hg 0.14 50 psig 0.27 5” Hg 0.18 100 psig 0.26 10” Hg 0.22 200 psig 0.25 20” Hg 0.26 300 psig 0.24 30” Hg 0.28 500 psig 0.22 ≥1000 psig 0.22 K values are from Koch-Otto York | Horizontal Mist Eliminator 26. Horizontal Mist Eliminator Side of a square Mist Eliminator = K-Values Conventional Mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.17 15 psig 0.35 1” Hg 0.17 50 psig 0.34 5” Hg 0.23 100 psig 0.32 10” Hg 0.28 200 psig 0.31 20” Hg 0.32 300 psig 0.30 30” Hg 0.35 500 psig 0.28 ≥1000 psig 0.27 Multi-Zone mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.14 15 psig 0.28 1” Hg 0.14 50 psig 0.27 5” Hg 0.18 100 psig 0.26 10” Hg 0.22 200 psig 0.25 20” Hg 0.26 300 psig 0.24 30” Hg 0.28 500 psig 0.22 ≥1000 psig 0.22 K values are from Koch-Otto York | Horizontal Mist Eliminator 26. Horizontal Mist Eliminator Side of a square Mist Eliminator = K-Values Conventional Mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.17 15 psig 0.35 1” Hg 0.17 50 psig 0.34 5” Hg 0.23 100 psig 0.32 10” Hg 0.28 200 psig 0.31 20” Hg 0.32 300 psig 0.30 30” Hg 0.35 500 psig 0.28 ≥1000 psig 0.27 Multi-Zone mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.14 15 psig 0.28 1” Hg 0.14 50 psig 0.27 5” Hg 0.18 100 psig 0.26 10” Hg 0.22 200 psig 0.25 20” Hg 0.26 300 psig 0.24 30” Hg 0.28 500 psig 0.22 ≥1000 psig 0.22 K values are from Koch-Otto York | Horizontal Mist Eliminator 26. Horizontal Mist Eliminator Side of a square Mist Eliminator = K-Values Conventional Mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.17 15 psig 0.35 1” Hg 0.17 50 psig 0.34 5” Hg 0.23 100 psig 0.32 10” Hg 0.28 200 psig 0.31 20” Hg 0.32 300 psig 0.30 30” Hg 0.35 500 psig 0.28 ≥1000 psig 0.27 Multi-Zone mist Eliminator Pressure K-Value Pressure K-Value <1” Hg 0.14 15 psig 0.28 1” Hg 0.14 50 psig 0.27 5” Hg 0.18 100 psig 0.26 10” Hg 0.22 200 psig 0.25 20” Hg 0.26 300 psig 0.24 30” Hg 0.28 500 psig 0.22 ≥1000 psig 0.22 K values are from Koch-Otto York |
| Mist Eliminator Liquid Loading The Design Engineer should assume that the vapor that flows to the mist eliminator contains entrained liquid equal to 1 wt% of the liquid entering the vessel. Based on this quantity of liquid, the Design Engineer should check that the mist eliminator liquid loading is less than 0.5 gpm/ft2 | Mist Eliminator Liquid Loading The Design Engineer should assume that the vapor that flows to the mist eliminator contains entrained liquid equal to 1 wt% of the liquid entering the vessel. Based on this quantity of liquid, the Design Engineer should check that the mist eliminator liquid loading is less than 0.5 gpm/ft2 | Mist Eliminator Liquid Loading The Design Engineer should assume that the vapor that flows to the mist eliminator contains entrained liquid equal to 1 wt% of the liquid entering the vessel. Based on this quantity of liquid, the Design Engineer should check that the mist eliminator liquid loading is less than 0.5 gpm/ft2 | |
4.4 Normal Level/Cross - Sectional Area/Residence Time Relationships
Figures 1A-1E
5. Guidelines for Sizing Vertical Vessels
The equations in Section 5.4 are the basis for WIN254, “Vertical Vessels”.
5.1 Surge/Storage Vessels
WIN254 Service Type = Surge, Vapor/Liquid or Vapor/Liquid/Liquid.
a. Determine the tangent length/diameter (L/D) ratio. Typical L/D values range from 1.5 to 5.0. An L/D value of 3.0 is most commonly applied.
b. Determine the liquid residence time and percent liquid full.
c. Calculate the vessel diameter to satisfy the residence time requirement using equation 27. If a surge drum must accommodate slugs of water, calculate the vessel diameter and tangent length using Figure 6, “Surge with Liquid/Liquid Separation” and equations 36 and 37.
d. Round off diameters and tangent lengths in English units to the next larger 6 inch increment if the dimensions are not already in even 6 inch increments. Round off diameters and tangent lengths in metric units to the next larger 100 millimeter increment if the dimensions are not already in even 100 millimeter increments.
5.2 Phase Separation Vessels Without Mist Eliminator
WIN254 Service Type = Surge or Separator (Vapor/Liquid or Vapor/Liquid/Liquid).
a. Calculate the vessel diameter for phase separation by using equations 28 and 29 for vapor/liquid separation and equations 34 and 35 for vapor/liquid/liquid separation.
b. Based on the calculated vessel diameter, determine whether an ellipsoidal or a flanged flat top head is suitable. Vessels smaller than 30 inches (750 mm) in diameter shall have a flanged flat top head (head may be flat or curved). Vessels with a diameter of 30 inches (750-800 mm) may have either type of top head. Vessels larger than 30 inches (800 mm) in diameter shall have an ellipsoidal top head. A 36 inch ASME Class 300 flanged flat head costs approximately 2.5 times more than a 36 inch ellipsoidal head with an 18 inch manway.
c. Determine the liquid level range for the vessel based on the surge time across the level controller (0-100%).
d. Calculate the vessel tangent length based on the type of top head, the liquid level range and any necessary surge time above the maximum controlled level (HLL) using Figure 2, “Vapor/Liquid Separation and equations 28 and 29 for vapor/liquid separation, and Figure 4, “Vapor Liquid/Liquid Separation” and equations 34 and 35 for vapor/liquid/liquid separation.
e. Round diameters and tangent lengths as discussed in Section 5.1.d.
5.3 Phase Separation Vessels With Mist Eliminator
WIN254 Service Type = Separator (Vapor/Liquid or Vapor/Liquid/Liquid).
a. Determine whether or not the vessel diameter is the same as the diameter of the mist eliminator. If excessive entrainment of liquid in the vapor outlet stream could be economically significant or detrimental to equipment, safety or operation (gas to reciprocating compressor), calculate the largest vessel diameter using equations 30-32 for vapor/liquid separation, and equations 30, 32 and 35 for vapor/liquid/liquid separation.
If the vessel diameter can be the same as the diameter of mist eliminator, use equation 33.
b. Based on the calculated vessel diameter, determine whether an ellipsoidal or a flanged flat top head is suitable. See Section 5.2.b.
c. Determine the liquid level range for the vessel.
d. Calculate the vessel tangent length based on the type of top head, the liquid level range and any necessary surge time above the maximum controlled level (HLL) using the equations in Figure 3, "Vapor/Liquid Separation with Mist Eliminator Demisting" for vapor/liquid separation and Figure 5, “Vapor/Liquid/Liquid Separation with Mist Eliminator Demisting” for vapor/liquid/liquid separation.
e. Round diameters and tangent lengths as discussed in Section 5.1.d.
5.4 Vertical Vessel Dimensions
27. Residence Time Where C = Figure 2 Vapor/Liquid Separation | A Cross-sectional area, ft2 C Coefficient, see equations, this page D Vessel I.D., ft DB Diameter of mesh blanket, ft DIN Nominal pipe diameter of inlet, in DON Nominal pipe diameter of outlet, in DPL Liquid particle diameter, ft *(0.00082 ft) DPHL Heavy liquid particle diameter, ft *(0.00041 ft) DPLL Light liquid particle diameter, ft *(0.00041 ft) DPV Vapor particle diameter, ft *(0.00057 ft) F Percent liquid full g 32.2 ft/sec2 L Tangent length, ft QTL Flow rate of total liquid phase, gpm QV Flow rate of vapor phase, ft3/sec t Liquid residence time, minutes L Liquid density, lb/ft3 HL Heavy liquid density, lb/ft3 LL Light liquid density, lb/ft3 V Vapor density, lb/ft3 L Liquid viscosity, lb/ft sec HL Heavy liquid viscosity, lb/ft sec LL Light liquid viscosity, lb/ft sec V Vapor viscosity, lb/ft sec * Use in the absence of specific process data. |
|---|---|
| 28. Gravity settling liquid from vapor phase 29. Disentraining vapor from liquid phase | 6” if DIN ≤ 2” (10” for flanged heads) 0.5DIN + 6” or DIN + 5” whichever is larger 0.4DB – 0.25D or 18”, whichever is larger 0.4DB (Min) 0.5DIN + 3’-0” 0.5D + 0.5DIN 0.5DIN + 2’-0” (limit) 0.5DIN + 4’-0” (limit) 0.5DIN + [larger of 1’-6” or 2 minutes of liquid surge] 0.5DON + 1’-0” 0.5 + 0.5DON 1’-9” + Note: Flowing data are at operating conditions |
| Figure 3
Vapor/Liquid Separation with Mist Eliminator Demisting | Figure 3
Vapor/Liquid Separation with Mist Eliminator Demisting | Figure 3
Vapor/Liquid Separation with Mist Eliminator Demisting | Figure 3
Vapor/Liquid Separation with Mist Eliminator Demisting | Figure 3
Vapor/Liquid Separation with Mist Eliminator Demisting | Figure 3
Vapor/Liquid Separation with Mist Eliminator Demisting |
|---|---|---|---|---|---|
| 30. Gravity settling liquid from vapor phase | 30. Gravity settling liquid from vapor phase | 30. Gravity settling liquid from vapor phase | |||
| 31. Disentraining vapor from liquid phase | 31. Disentraining vapor from liquid phase | ||||
| 32. Mist eliminator diameter requirements are provided below. The equations are based on sizing DB at the 100% point. The mist eliminator operating range is 30 – 110% Style “A” should be applied as the default mist eliminator style. For flanged flat top head ( D 2’-6”) | 32. Mist eliminator diameter requirements are provided below. The equations are based on sizing DB at the 100% point. The mist eliminator operating range is 30 – 110% Style “A” should be applied as the default mist eliminator style. For flanged flat top head ( D 2’-6”) | 32. Mist eliminator diameter requirements are provided below. The equations are based on sizing DB at the 100% point. The mist eliminator operating range is 30 – 110% Style “A” should be applied as the default mist eliminator style. For flanged flat top head ( D 2’-6”) | 32. Mist eliminator diameter requirements are provided below. The equations are based on sizing DB at the 100% point. The mist eliminator operating range is 30 – 110% Style “A” should be applied as the default mist eliminator style. For flanged flat top head ( D 2’-6”) |
| For ellipsoidal top head | For ellipsoidal top head |
|---|---|
| S Values S = 0.3 ft for DB < 6’-0” = 0.5 ft for DB 6’-0” but < 12’-0” = 0.8 ft for DB 12’-0” but < 18’-0” = 1.0 ft for DB 18’-0” but < 24’-0” = 1.1 ft for DB 24’-0” but < 30’-0 |
K-Values
Style “A” Conventional Mist Eliminator
Pressure K-Value Pressure K-Value
<1” Hg 0.17 15 psig 0.35
1” Hg 0.17 50 psig 0.34
5” Hg 0.23 100 psig 0.32
10” Hg 0.28 200 psig 0.31
20” Hg 0.32 300 psig 0.30
30” Hg 0.35 500 psig 0.28
≥1000 psig 0.27
Mist Eliminator
Pressure K-Value Pressure K-Value
<1” Hg 0.14 15 psig 0.28
1” Hg 0.14 50 psig 0.27
5” Hg 0.18 100 psig 0.26
10” Hg 0.22 200 psig 0.25
20” Hg 0.26 300 psig 0.24
30” Hg 0.28 ≥500 psig 0.22
K values are from Koch-Otto York
Partial/Full Mist Eliminator
33a. If DB + 0.66 < DSeparation, then use a partial mist eliminator.
33b. If DB + 0.66 ≥ DSeparation, then Set D=DB + 0.66 and use a full mist eliminator. If D is not an even 6” (100) interval, round off to next larger 6” (100) interval.
Vapor-Liquid Mist Eliminator Loading
The Design Engineer should assume that the vapor that flows to the mist eliminator contains entrained liquid equal to 1 wt% of the liquid entering the vessel. Based on this quantity of liquid, the Design Engineer should check that the mist eliminator liquid loading is less than 0.5 gpm/ft2.
| Figure 4 Vapor/Liquid/Liquid Separation | Figure 4 Vapor/Liquid/Liquid Separation |
|---|---|
| 34. Gravity settling liquid from vapor phase |
| 35. Disentraining vapor from liquid phase and gravity settling heavy liquid phase from light liquid phase. | 35. Disentraining vapor from liquid phase and gravity settling heavy liquid phase from light liquid phase. |
|---|---|
| For | (With C1, enter table of circular segmental functions (handbook) and obtain chord height/diameter value, C2.) |
| = DxC2 For = D - |
| Figure 5 Vapor/Liquid/Liquid Separation with Mesh Blanket Demisting |
|---|
For D, DB, and , see Equations 30, 32 and 35. |
| Figure 6 Surge with Liquid/Liquid Separation |
|---|
36. Gravity settling heavy liquid phase from light liquid phase
A = 0.15 A A =
| For | (With C1, enter table of circular segmental functions (handbook) and obtain chord height/diameter value, C2.) |
|---|---|
| = DxC2 For = D - |
37. Surge height =
© 2026 Inflection Point Engineering, LLC. All rights reserved. The content of this page — including calculation methods, reference data, written analysis, interactive tools, and source code — is the intellectual property of Inflection Point Engineering, LLC and is protected under applicable copyright, trademark, and trade secret laws. Unauthorized reproduction, redistribution, modification, or derivative use in whole or in part is prohibited without prior written consent.
Disclaimer. This material is provided for informational and educational purposes only and does not constitute professional engineering advice. Calculations, reference data, and methodologies are based on published standards and accepted engineering practice but are not a substitute for engineering judgment, site-specific analysis, or review by a licensed Professional Engineer. Inflection Point Engineering, LLC makes no warranties, express or implied, regarding the accuracy, completeness, or fitness for a particular purpose of any content presented here, and shall not be liable for any direct, indirect, incidental, or consequential damages arising from its use. Users assume all risk associated with applying this content to real-world design, operations, or decisions.
© 2026 Inflection Point Engineering, LLC. All rights reserved.