Flash distillation operation is suitable for separating components which
A.boil at very close temperature
B.boil at widely different temperature
C.form minimum boiling azeotrope
D.form maximum boiling azeotrope
Category: Mass Transfer Mcqs
The flash process is carried out by
A.reducing the pressure on the feed stream
B.cooling the feed at constant pressure
C.increasing the pressure on the feed steam
D.none of the above
Relative volatility ? for a binary system is a measure of separability by distillation. If ? = 1 the separation by distillation is
A.maximum possible
B.least possible
C.impossible
D.optimum possible
The temperature of water cooled in a cooling tower is
A.always less than the wet-bulb temperature of entering air
B.always equal to the wet-bulb temperature of entering air
C.always greater than the wet-bulb temperature of entering air
D.always equal to the dry-bulb temperature of entering air.
The temperature at which a vapour-gas mixture becomes saturated when cooled at constant total pressure out of contact with a liquid is called
A.bubble point
B.dew point
C.wet-bulb temperature
D.dry-bulb temperature
If there is no condensation of carrier steam in the steam distillation of high-boiling organic materials the steam consumption is minimum at
A.the highest permissible temperature and pressure
B.the lowest practicable temperature and pressure
C.the highest permissible temperature and the lowest practicable pressure
D.the lowest temperature and the highest practicable pressure
McCabe ? Thiele method is used to find the number of theoretical stages required in a distillation operation. This method is based on the assumption(s) that
A.the liquid/vapour loading in each section of the tower remains constant
B.Troutons rule is applicable
C.the sensible heat differences are small because the temperature change from tray to tray is small
D.all of the above
In the design of cooling towers the wet-bulb temperature approach is ordinarily specified to be
A.from 5 to 10?F
B.from 20 to 30?F
C.from 30 to 35?F
D.from 10 to 25?F
