Souders-Brown Equation


A vapor–liquid separator drum is a vertical 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(or a flashing liquid) is fed and wherein the liquid is separated by gravity, falls to the bottom of the vessel, and is withdrawn. The vapor travels upward at a design velocity which minimizes the entrainment of any liquid droplets in the vapor as it exits the top of the vessel.
The Souders-Brown equation has been the tool for obtaining the maximum allowable vapor velocity in vapor-liquid separation vessels (variously called flash drums, knockout drums, knockout pots, compressor suction drums and compressor inlet drums).

Related formulas


VMaximum Allowable Vapor Velocity (m/s)
kVapor Velocity Factor ( 0.107 m/s when the drum includes a de-entraining mesh pad) (m/s)
p2Vapor Density (kg/m3)
p1Liquid Density (kg/m3)