Vertical Gas-Liquid Separator

Calculate vessel sizing for a vertical gas-liquid separator.

Vertical Separator Sizing Calculator Guide (PDF)

This calculator is used to size vertical gas-liquid separators such as knock-out drums. The calculator determines the vessel diameter and height required to achieve the specified separation. The calculation method is based on the procedure described in "Rules of Thumb for Chemical Engineers" by Carl Branan.

The calculator automatically calculates the Souders-Brown separator sizing factor based on the specified liquid and gas flow rates and densities.

  1. Enter the mass flow rate of liquid entering the separator
  2. Enter the mass flow rate of gas or vapour entering the separator
  3. Enter the density of the liquid entering the separator
  4. Enter the density of the gas or vapour entering the separator
  5. Enter the required liquid hold-up time the separator must provide. Typical values are:
    • Tower reflux drums: 5 - 10 mins
    • Knock-out drums: 5 mins
    • Fractionation feed surge tanks: 8 - 15 mins
  6. Click the "Calculate" button
  7. The calculator will determine the separator vessel diameter, tan-to-tan height and length to diameter ratio
  8. The calculator will also determine the gas and liquid volumetric flow rates to the vessel, the separator sizing factor and associated parameters
Vertical Separator Diagram
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INPUTS
Liquid mass flow rate ml
Gas mass flow rate mv
Liquid density ρl
Gas density ρv
Liquid residence time τl
OUTPUTS
Liquid volume flow rate Ql 0.20
Gas volume flow rate Qv 800.00
Mixture density ρmix 1.50
Separation factor Sf 0.0071
K factor K 0.0795
Max vapour velocity uvapmax 2.247
Min cross-sectional area Amin 0.09889
Min vessel diameter Dmin 0.355
Max nozzle velocity unozmax 99.61
Min nozzle velocity unozmin 59.77
Max inlet nozzle diameter dinlet max 0.069
Inlet nozzle diameter dinlet 3
Liquid holdup volume Vl 0.017
Liquid height hl 0.105
Vapour height above inlet hvabove 1.200
Vapour height below inlet hvbelow 0.450
Vessel length L 1.755
Separator diameter Dsep 0.450
Length to diameter ratio L:D 3.90
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