Souders-Brown Equation

Souders-Brown equation is used to find the maximum allowable vapor velocity in vapor-liquid seperation vessels.

 

Souders-Brown Equation formula

\(\large{ v =  K \;  \sqrt{ \frac{\rho_l \;-\; \rho_v}{\rho_v} }    }\)

Where:

\(\large{ v  }\) = maximum allowable vapor velocity

\(\large{ \rho_l }\)   (Greek symbol rho) = density of liquid

\(\large{ \rho_v }\)   (Greek symbol rho) = density of vapor

\(\large{ K }\) = vapor velocity factor

K Factors for maximum allowable superficial velocity (API Spec 12J)

• Vertical separator  -  5 ft. high  -  K = 0.12 to 0.24
• Vertical separator  -  10 ft. high  -  K = 0.18 to 0.35
• Horizontal separator  -  10 ft. long  -  K = 0.40 to 0.50
• Horizontal separator  -  Other lengths L ft. long  -  K = 0.40 to 0.50 \(\left( \frac{L}{10}\right)^{0.56} \)
• Spherical separator  -  All  -  K = 0.2 to 0.35