250+ TOP MCQs on Packing Material – Random Packing and Answers

Basic Distillation Design Questions and Answers on “Packing Material – Random Packing”.

1. A layer of packing above the liquid distributor is called?
a) Dry packing
b) Wet packing
c) Can packing
d) Trump packing
Answer: a
Clarification: A layer put above the liquid distributor is called dry packing, which acts as an entrainment eliminator, to remove the entrainment liquid droplets.

2. The Eckert chart contains a parameter F_P which is called?
a) Pushing factor
b) Possibility factor
c) Praining factor
d) Packing factor
Answer: d
Clarification: A parameter _P that characteristics the packing and is called as packing factor, originally introduced by Lobo in 1945, also represented as C_f.

3. The packing factor used to be taken as?
a) a_p/e³
b) a_p/e²
c) a_p²/e²
d) a_p³/e⁴
Answer: a
Clarification: The packing factor is taken as to be a_p/e³, where a_p= surface of the packing per unit volume and e = void fraction of the packed bed.

4. The difference between the total hold up and the static holdup is called?
a) Static holdup
b) Operating holdup
c) Dynamic holdup
d) Full holdup
Answer: b
Clarification: The difference between the total hold up and the static holdup is called Operating holdup and sometimes is also refereed as dynamic holdup.

5. The MWR stands for?
a) Maximum Working Rate
b) Mixed Working Rate
c) Minimum Wetting Rate
d) Mega Weeping Rate
Answer: a
Clarification: It is the liquid throughput below the film packing surface breaks up reducing the wetted area.

6. Liquid remaining in unit volume of bed after bed is drained is?
a) Final holdup
b) Total holdup
c) Static holdup
d) Full holdup
Answer: c
Clarification: It is the liquid remaining in unit volume of the bed after the bed is drained for a reasonable time, it is pretty small compared to total holdup.

7. F_s is denoted as?
a) Capacity parameter
b) Final storage
c) Full standup
d) Finishing Standup
Answer: a
Clarification: Plot of dP vs. F_s, it may be noted that quantity F_s is also taken as a measure when p_g<

8. Minimum liquid rate for random packing is reported as?
a) 10-14 gpm/ft²
b) 8-10 gpm/ft²
c) 1-9 gpm/ft²
d) 0.5-2 gpm/ft²
Answer: d
Clarification: Minimum liquid rate for random packing is reported as 0.5-2 gpm/ft² and for structured packing is 0.1-0.2 gpm/ft².

9. The dry bed pressure drop can be calculated using?
a) Ergun’s Equation.
b) Fenske’s Equation
c) Bessel’s Equation
d) Barnaul’s Equation
Answer: a
Clarification: The Ergun’s equation can be used using the pressure drop calculation for all the packed towers and other equipment’s that use packings.

10. The quantity C_s is?
a) Capricorn Constant
b) Souder’s-Brown constant
c) Sider Tate equation
d) Chaperon Equation
Answer: b
Clarification: The quantity C_s is akin Souder’s-Brown constant, may be corrected for changes in interfacial tension and viscosity if necessary.

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