Process Equipment and Plant Design MCQs

molal flow rate of vapour

vapour molecular weight

pressure and temperature

all (a), (b) and (c)

Distillation under vacuum is a substitute for steam distillation.

In differential (simple) distillation, the vapour is removed as soon as it is formed without appreciable condensation.

In flash (equilibrium) distillation, a definite fraction of liquid is vaporised in such a way that the evolved vapour & residual liquids are in equilibrium with each other.

Flash distillation, differential distillation & steam distillation are all continuous distillation processes.

of its flexibility and nearly constant efficiency under varying conditions of operation.

it incurs less pressure drop as compared to any other try designed for the same duty.

it eliminates the foaming and entrain-ment tendency during operation.

none of these.

less

more

same

either (a) or (b); no generalisation can be made

0.1 to 2

5 to 7

3 to 8

8 to 15

gas density

gas viscosity

fibre selection

all (a), (b) & (c)

Di, opt = 3.9 Q0.45 ρ0.13

Di, opt = 3.9 Q0.45 . μ0.95

Di, opt = 4.7 Q0.36 . μ3.2ρ0.13

Di, opt = 3 Q0.36 . μ0.88

pd/2t

pd/4t

pd/t

pd/8t

horizontal cylinderical

tall vertical

thick walled vertical

thick spherical

an increase in liquid viscosity.

an increase in relatived volatility for rectification columns.

decrease in gas solubility for absorbers.

all (a), (b) and (c).