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Two Phase Separator Sizing - Vertical (Simpler Version) - Beta
Step 1 - Input Process Conditions
Operating Pressure, Pg
psig
Atmospheric pressure, Pa
psia
Operating Temperature, Tf
deg.F
Standard volumetric flow of gas, Qgs
mmscfd
Molecular Weight of gas, MW
lb/lbmol
Compressibility Factor, Z
Viscosity of gas, mu_g
cP
Volumetric flow rate of liquid, Ql
ft3/min
Density of liquid, rho_l
lb/ft3
Viscosity of liquid, mu_l
cP
Required Hold Up Time (LLL to NLL), th
min
Required Surge Up Time (NLL to HLL), ts
min
Calculated density of gas, rho_g
lb/ft3
Mass flow rate of gas, mg
lb/min
Actual volumetric flow rate of gas, Qg
ft3/min
Calculated Mixed fluid density rho_m
lb/ft3
Calculate1
Step 2 - Calculate K Value
Calculated K Value, Kcalc
ft/s
Selected K value, K
ft/s
Calculated particle terminal velocity, Vmax
ft/s
Allowance for support ring, Da (typ 4 in)
in
Calculated inside diameter of vessel, Di_calc
in
Selected inside diameter, Di
in
Calculate2
Step 3 - Check Inlet Velocity Head
Nozzle Pipe Nominal Size and Schedule
Selected Pipe Outside Diameter, NDo1
in
Selected Pipe Nominal Wall Thickness, Tn1
in
Selected Pipe Inside Diameter, NDi1
in
Inlet Velocity, Vin
ft/s
Gas velocity head, J1
lb/(ft*s2)
Gas velocity head limit, J1_Limit (See Help)
lb/(ft*s2)
Verify2 (Vl <= Vt):)
in
Calculate3
Step 4 - Check Outlet Velocity Head
Nozzle Pipe Nominal Size and Schedule
Selected Pipe Outside Diameter, NDo2
in
Selected Pipe Nominal Wall Thickness, Tn2
in
Selected Pipe Inside Diameter, NDi2
in
Outlet Velocity, Vout
ft/s
Gas velocity head, J2
lb/(ft*s2)
Gas velocity head limit, J2_Limit (See Help)
lb/(ft*s2)
Verify3 (J2 <= J2_Limit):
in
Calculate4
Step 5 - Set Levels and heights
Required Volume for Hold UP Section, Vh
ft3
Required Volume for Surge Section, Vs
ft3
Low Liquid Level Height (typ 12 in to 18 in), H_LLL
in
Calculated Height from LLL to NLL (Hold Up), Hh_calc
in
Height from LLL to NLL (Hold Up), Hh
in
Calculated Height from LLL to NLL (Hold Up), Hs_calc
in
Height from NLL to HLL (Surge), Hs
in
Feed Nozzle inside diameter selected, dn
in
Height calculated from HLL to the center line of the inlet nozzle (typ 12 in + dn), Hin_calc
in
Height from HLL to the center line of the inlet nozzle, Hin
in
Disengagement Height calculated from the centreline of the inlet nozzle to the bottom of the demister pad, Hd
in
Disengagement Height from the centreline of the inlet nozzle to the bottom of the demister pad, Hd
in
Mist eliminator height (typ 4in to 6in), Hme
in
Mist eliminator top to top seam/tan height (typ 12 in), Hmt
in
Total height of the vessel, Ht
in
Calculate5
Step 6 - Final Design
Diameter of the vessel and Feed Nozzle
Selected inside diameter, Di
in
Selected inside diameter, Di_ft
ft
Selected Feed nozzle Size and Schedule, NDi1
Cumulative levels and heights from bottom seam (or tan)
Low low liquid level, H_LLL
in
Height from LLL to NLL (Hold Up), Hh
in
Height from NLL to HLL (Surge), Hs
in
Height from HLL to the center line of the inlet nozzle, Hin
in
Disengagement Height from the centreline of the inlet nozzle to the bottom of the demister pad, Hd
in
Mist eliminator height, Hme
in
Mist eliminator top to top seam/tan height, Hmt
in
Total height of the vessel (Seam to Seam) or (tan to tan), Ht
in
Retention Volume and Retention Time
Height of the normal liquid level (NLL) from vessel bottom seam/tan, H_NLL
in
Retention Volume (Seam / tan to NLL), Vr
ft3
Retention time, tr
min
Calculate6
Sketch
Help
General Notes:
Note: Refer to the "Terms and Conditions" in the 'About' section before using the software.
1) Two Phase Vertical Separator Sizing is a software program that can be used to size 2 phase vertical liquid / vapour (gas) separators.
2) The procedure is based on Chapter 7 - Separation Equipment, presented in GPSA 14th edition.
3) The separator in consideration is assumed to be equipped with a mist extractor. The software is not designed and hence should not be used for other types such as vane type separators. Heads on either ends of the shell are not considered for volume calculations such as surge volumes, retention volumes etc., for the sake of simplicity.
4) The user needs to select / fill in relevant input data under Step1' and then click 'Calculate1' button so the program calculates the relevant parameters. The user then needs to fill in relevant data under 'Step2' and click 'Calculate2' button and so on. The procedure needs to be followed sequentially. When an update to any input is made, the procedure needs to be followed sequentially again by clicking the buttons in sequence, so the calculations are updated under each step.
5) Typical control surge times (LLL to HLL) for liquids for various types of separator vessels are as below.
Compressor Drum : 2 minutes
Flash Drum : 2 - 5 minutes
Reflux Drum: 5 minutes on product plus reflux
Surge Drum upstream of a Tower: 5-10 minutes
Surge Drum upstream of a Fired heat: 10 minutes
Net Product to Storage: 5 minutes
Refrigeration Accumulator: 5 minutes, or based on system or storage requirements
Refrigeration Economizer: 3 minutes
Heat Medium Surge Drum: Maximum liquid expansion, based on 25% to 75% full
6) Typical retention times (empty to NLL) for liquids for various types of separator vessels as as below.
Amine Flash Drum : 5 - 10 minutes, depending on presence of hydrocarbons
Glycol Flash Drum : 10 - 20 minutes, depending on presence of hydrocarbons
Cold Separator: Gas / NGL / Ethylene Glycol : 15 - 30 minutes, depending on internals
7) Suggested mixed phase velocity head range for the inlet nozzle, J_Limit
Diffuser distributor: 4,000 - 6,000 max lb/ft • sec2
No inlet distributor : 650 - 1,500 max lb/ft • sec²
Inlet half pipe or elbow distributor: 1,000 - 2,500 max lb/ft • sec2
V-baffle or other simple invert diverter designs: 1,000 - 2,500 max lb/ft sec2
Cyclonic inlet device: upto 10,000 lb/ft • sec2
Suggested outlet velocity head range, J_Limit: 3000 - 3600 max lb/ft • sec2
8) All numbers / amounts need to be entered without commas or $ sign. Empty boxes, non-numerical values are not allowed where numbers are expected.
9) Please provide any constructive feedback so we can improve the quality of the software.