Process Equipment and Plant Design
Pressure drop due to pipe fittings can be estimated by the equation, ΔP/p = 4f.Le/D.V2/2gc, where, Le = equivalent length of straight pipeline which will incur the same frictional loss as the fitting and D = diameter of the fitting. The value of Le/D (dimensionless) for 45° elbow and 180° close return bends would be respectively around

180 and 300
45 and 75
5 and 10
300 and 500

ANSWER DOWNLOAD EXAMIANS APP

Process Equipment and Plant Design
Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 - 1.4 cp and relative volatility < 4) (where η = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi)

Η = 1.66 - 0.25 log μ
Η = 0.25 log μ - 1.67
Η = 17 - 61.1 log μ
Η = 24.6 (Δp/μ)

ANSWER DOWNLOAD EXAMIANS APP