Page 49 - Separation process engineering

kg/m 3

Δt
change in time, s, min, or h

ΔT f
change in fluid temperature, °C or K

Δz

increment of column length, m
γ

volumetric purge to feed ratio in PSA, dimensionless, Eq. (18-26)
ε e

external porosity, dimensionless
ε p

internal or pore porosity, dimensionless

ε
T
total porosity, dimensionless, Eq. (18-1b)
ρ b

3
bulk density of adsorbent, kg/m , Eq. (18-3b)
ρ f

fluid density, kg/m 3

molar density of fluid, kmol/m 3
ρ p

3
particle density, kg/m , Eq. (18-3a)
ρ s

structural density of solid, kg/m 3
σ

standard deviation of Gaussian chromatographic peak, Eq. (18-79)

σ l
standard deviation in length units, m or cm, Eq. (18-80b)

σ t

standard deviation in time units, min or s, Eq. (18-80a)
τ

tortuosity, dimensionless, Eq. (18-4)
ζ

Greek letter zeta used as dummy variable in Eq. (18-70)