In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalent to a theoretical plate HTUOG = overall gas phase height of a transfer unit) ?

Related Mcqs:

1. In a packed absorption tower, if the equilibrium and operating lines are both straight lines, then the ratio, HETP/HTUOG ______________ the absorption factor?

   A. Increases with increase in
   B. Is one at unity value of
   C. Both A. and B.
   D. Neither A. nor B.

2. H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H2S has to be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower (in meters) corresponding to an operating line given by, y = 5x + 0.001 is ______________________?

   A. 2.0
   B. 1.56
   C. 1.0
   D. 0.56

3. For the gas absorption, the height of a transfer unit, based on the gas phase is given by (G: superficial molar gas velocity, L: superficial molar liquid velocity, FG: mass transfer co-efficient, moles/m2, a: interfacial area per unit volume of tower) ?

   A. G/(FG . a)
   B. FG/(G . a)
   C. (G . a)/FG
   D. L/(FG . G)

4. At the same gas flow rate, the pressure drop in a packed tower being irrigated with liquid _______________ that in dry packed tower ?

   A. Is greater than
   B. Is lower than
   C. Is same as
   D. Cannot be predicted as data are insufficient

5. A packed tower compared to a plate tower for a particular mass transfer operation__________________?

   A. Incurs smaller pressure drop
   B. Allows installation of cooling coils
   C. Is less costly when built in large sizes/diameters
   D. Is more suitable, if suspended solids are present in fluid streams

6. Experiments were conducted to determine the flux of a species A in a stagnant medium across a gas-liquid interface. The overall mass transfer co-efficient based on the liquid side for dilute systems for the above was estimated to be 4 × 10-3 kg mole/m2.s. The equilibrium data for the system is given as y = 2x. The flux across the interface (in kg mole/m2 .s) for bulk concentrations of A in gas phase and liquid phase as y = 0.4 and x = 0.01 respectively is _________________________?

   A. 5.6 × 10-4
   B. 8.5 × 10-4
   C. 5.6 × 10-3
   D. 8.5 × 10-3

7. The reason for preferring packed towers over plate towers in distillation practice is that the packed tower operation gives___________________?

   A. Low pressure drop and high hold up
   B. High pressure drop and low hold up
   C. Low pressure drop and low hold up
   D. High pressure drop and high hold up

8. Pressure drop through plate tower as compared to that through packed tower, for the same duty will be___________________?

   A. Less
   B. More
   C. Equal
   D. Either A. or B.; depends on the packing height

9. If the overall efficiency and Murphree plate efficiency are equal, then both the equilibrium and operating lines are_______________?

   A. Straight
   B. Parallel
   C. Both A. & B.
   D. Neither A. nor B.

10. In McCabe-Thiele method of theoretical plate calculation for a distillation column, the operating lines of stripping and rectifying sections coincide with the diagonal at ________________ reflux ?

    A. Total
    B. Minimum
    C. Operating
    D. Maximum permissible