Test 1 - Fall 2021 Flashcards
Fick’s Law is used to
determine the ss flux of a component
What is always true for equimolar diffusion with any two components (A & B)?
Ja = -Jb
In a binary system, the higher the concentration of the less volatile species in the feed to a flash drum
the higher the liquid flow rate leaving the drum
Ki=
yi=xi
Relative Volatility of components i and j can be defined as
Ki/Kj
Energy balance around a distillation column
Fhf + Qc + Qr = Dhd + Bhb
Material balance around a condenser
V = L + D
Reflux ratio
L/D
If the feed enters the distillation column at its dew point, then the slope of the feed line is
0
At total reflux
distillate is 0
At minimum reflux, the number of stages is
infinite
The slope of the top of the operating line in distillation is
L/V
The intercept of the bottom operating line in distillation is
(1-Lbar/Vbar)*Xb
Column diameter is most dependent on
vapor velocity
To determine tray spacing, use:
Propensity of liquid to foam/entrain; Need for person to access top of trays
The phenomena of the flowing liquid towards the wall of tower and dispersed in lateral direction is called as
channeling
Overall efficiency is
0.5 to 0.7
When sizing a column, switching trays to packing usually results in
decreased height
HEPT stands for
height equivalent to theoretical plate
