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INPUT   DATA

♥ EXAMPLE Of Input/Output

Title

Liquid flow rate		lb/hr
Vapor flow rate		lb/hr
Liquid density		lb/ft3
Vapor density		lb/ft3
Length-to-diameter ratio
Fraction occupied by vapor

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OUTPUT   VARIABLES   &   GRAPHS

Variables	Values	Units
♦  Vapor-liquid separation factor
♦  Vapor velocity factor
♦  Maximum vapor velocity		ft/s
♦  Vapor volumetric rate		ft3/s
♦  Vessel diameter		ft
♦  Vessel length		ft
♦  Vessel volume		ft3
♦  Liquid surge time		min

Sizing Of Horizontal Separators

A vapor-liquid separator (or knockout) drum is a vessel into which a liquid and vapor mixture (or a flashing liquid) is fed and wherein the liquid is separated by gravity, falls to the bottom of the vessel (settling), and is withdrawn. The vapor travels at a design velocity which minimizes the entrainment of any liquid droplets in the vapor as it exits the top of the vessel.
The size a vapor-liquid separator drum should be dictated by the anticipated flow rate of vapor and liquid from the process vessel. The sizing methodology implemented here involves using correlations for maximum vapor velocity factors, the Souders & Brown equation, coupled with the liquid surge capacity as described in Coker.

The Souders-Brown equation is given as:
V = K [(ρ_L - ρ_V)/ρ_V]^0.5

where
     V = maximum allowable vapor velocity
     K = vapor velocity factor
     ρ_V = vapor density
     ρ_L = liquid density

Tips

    ◊ Use link EXAMPLE Of Input/Output  to demo data entry expectations and results; you may edit & use it as starting point

BIBLIOGRAPHY

• Coker, AK; Fortran Programs For Chemical Process Design, Analysis & Simulation; Gulf Publ. Co, Houston, 1995.
• Chopey, NP; Handbook of Chemical Engineering Calculations; McGraw Hill, New York, 2003.