Engineering-Stream - Software for Engineering Applications

Two Phase Separator Sizing - Horizontal (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
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

Step 2 - Input Holdup / Surge Times

Hold up time - LLL to NLL, th    min
Surge time - NLL to HLL, ts    min
Required Volume for Hold-up Section - Vh    ft3
Required Volume for Surge Section - Vs    ft3
Select Length over diameter ratio, L/D (range 1.5 to 6, typical-3)
Calculated inside diameter of vessel, Di_calc_in    in
Calculated length of vessel, Lcalc (seam to seam or tan to tan)    ft

Step 3 - Select Inside Diameter / Length of the vessel

Selected inside diameter of vessel, Di_in    in
Selected inside diameter of vessel, Di    ft
Selected length of vessel, L (seam to seam or tan to tan)    ft

Step 4 - Set Liquid Levels

Bottom to LLL, H_LLL (min 12 in)    in
Bottom to NLL, H_NLL (typ initial value - Di / 2.0)    in
Recommended vapor space, Hvr (Larger of 0.2*D or 2 ft)    in
Selected Vapor space, Hv    in
Verify1 (Hv >= Hvr) :
Calculated K value, Kcalc
Selected K value, K
Critical or Terminal Velocity, Ut    ft/s
Safety Factor for velocity of vapour, Usf (typ. 0.75)
Vapour velocity limit, Uvr    ft/s
Liquid dropout time, phi    s
Actual vapour velocity, Uva    ft/s
Minimum length required for vapour-liquid disengagement, Lvl    ft
Minimum length of vessel to accommodate Liquid Holdup and Surge, Lhs    ft
Minimum length of vessel to accommodate Liquid Holdup, Lh    ft
Selected length of vessel, L    ft
Verify2 (L >= Lvl) :
Verify3 (L >= Lhs) :
Verify4 (L >= Lh) :

Step 5 - Final Design

Diameter/Length of the vessel

Selected inside diameter, Di    ft
Selected inside diameter, Di_in    in
Total Vessel Length (Seam to Seam) or (tan to tan), L    ft

Cumulative levels from the I/S bottom and heights

Low liquid level (LLL), H_LLL    in
Normal liquid level (NLL), H_NLL    in
High liquid level (HLL), H_HLL    in
HLL to I/S top of vessel (vapour space), Hv    in

Retention Volume and Retention Time

Vessel Bottom to NLL, H_NLL    in
Retention Volume (vessel bottom to NLL), Vr    ft3
Retention time, tr    min

Help

General Notes:

Note: Refer to the "Terms and Conditions" in the 'About' section before using the software.

1) Two Phase Horizontal Separator Sizing is a software program that can be used to size 2 phase horizontal liquid / vapour (gas) separators.

2) The procedure is based on Chapter 7 - Separation Equipment, presented in GPSA 14th edition / other references used in industry.

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 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.