Engineering-Stream - Software for Engineering Applications

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
Mass flow rate of gas, Wg    lb/hr
Molecular Weight of gas, MW    lb/lbmol
Compressibility Factor, Z
Viscosity of gas, mu_g    cP
Mass flow rate of light liquid, W_LL    lb/hr
Density of light liquid, rho_LL    lb/ft3
Viscosity of light liquid, mu_LL    cP
Mass flow rate of heavy liquid, W_HL    lb/hr
Density of heavy liquid, rho_HL    lb/ft3
Viscosity of heavy liquid, mu_HL    cP
Required Hold Up Time (LLL to NLL), th    min
Required Surge Up Time (NLL to HLL), ts    min
Calculated density of gas, rho_V    lb/ft3
Actual volumetric flow rate of gas, Q_V    ft3/min
Mixed Liquids density, rho_L    lb/ft3
Mixture fluid density, rho_m    lb/ft3

Step 3 - Set Levels and heights

Selected inside diameter of vessel (in), Di    in
Selected inside diameter of vessel (ft), Di_ft    ft
Stoke's law terminal velocity constant (eg., 0.163 or 0.333 - see below), ks    (in/min)(cP)/(lb/ft3)
Settling velocity of the heavy liquid out of the light liquid, U_HL    (in/min)
Rising velocity of the light liquid out of the heavy liquid, U_LH    (in/min)
Height from Liquid interface to Light Liquid Nozzle (initially assume 1 ft), H_L    ft
Settling time for the heavy liquid droplets to settle through H_L, t_HL    min
Height for the light liquid droplets to rise (initially assume 1 ft), H_H    ft
Settling time for the light liquid droplets to rise through H_H, t_LH    min
Height from Light Liquid Nozzle to Baffle (initially assume 0.75 ft (9 in)), H_R    ft
Light liquid volumetric flow rate, Q_LL    ft3
Heavy liquid volumetric flow rate, Q_HL    ft3
Density difference between liquid and vapor for baffle design (rho_L - rho_V), rho_diff    gph/ft2
Allowable downflow for baffle design (range 6000 to 8000, for rho_diff values 20 to 50 approx, conservatively), G    gph/ft2
Residence time of light liquid based on the volume, theta_LL    min
Residence time of heavy liquid based on the volume, theta_HL    min
Verify1 (theta_LL >= t_LL) :
Verify2 (theta_HL >= t_LH) :
Height of light liquid above the outlet (Hold Up height) based on the liquid Hold up time, H_R_calc    ft
Verify3 (H_R >= H_R_calc) :
Surge height based on surge time, H_S    min
Calculated inlet nozzle diameter, dN_min    in

Step 4 - Set Levels and heights (Continued)

Selected inlet nozzle diameter, dN    in
Light liquid level above baffle (typically 0.5 ft), H_A    ft
Calculated liquid height from above baffle to Feed nozzle, H_BN_calc    ft
Selected liquid height from above baffle to Feed nozzle, H_BN    ft
Calculated height from Feed nozzle to bottom of mesh pad (disengagement height), H_D_calc    ft
Selected height from Feed nozzle to bottom of mesh pad (disengagement height), H_D    ft
Mehs Pad height (typically 0.5 ft), H_MP    ft
Height from top of mesh pad to vessel seam (typically 1.0 ft), H_MP_TOP    ft

Step 5 - Final Design

Diameter of the vessel and Feed Nozzle

Selected inside diameter, Di    in
Selected inside diameter, Di_ft    ft
Selected Feed nozzle diameter, dN    in

Levels and heights

Height for the light liquid droplets to rise, H_H    ft
Height from Liquid interface to Light Liquid Nozzle, H_L    ft
Height from Light Liquid Nozzle to Baffle, H_R    ft
Light liquid level above baffle, H_A    ft
Liquid height from above baffle to Feed nozzle, H_BN    ft
Selected height from Feed nozzle to bottom of mesh pad (disengagement height), H_D    ft
Mehs Pad height (typically 0.5 ft), H_MP    ft
Height from top of mesh pad to vessel seam (typically 1.0 ft), H_MP_TOP    ft
Total height of the vessel (Seam to Seam) or (tan to tan), H_T    ft

Retention Volume and Retention Time

Height of the normal liquid level (NLL) from vessel bottom seam/tan, H_NLL    ft
Retention Volume (Seam / tan 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) Three Phase Vertical Separator Sizing is a software program that can be used to size 3 phase vertical liquid / liquid / vapour (gas) separators.

2) The procedure is a simplified version based on Chapter 7 - Separation Equipment, presented in GPSA / industry standards.

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 need to be entered without commas. Empty boxes, non-numerical values are not allowed where numbers are expected.

9) Enter data in Cells with white background. Cells with gray background show calculated values.

10) Please provide any constructive feedback so we can improve the quality of the software.