Related Mcqs:

1. The operating velocity in the absorption tower is usually 40-50% of the flooding velocity. Packed absorption towers are normally designed for a pressure drop of about _________________ mm of water column per metre height of packing?

   A. 1-5
   B. 20-40
   C. 100-150
   D. 1000-1500

2. Which of the following factors affect the pressure drop in a co-current gas-liquid absorption packed tower ?

   A. Size, shape, orientation and surface of the packing particles
   B. Density and viscosity of fluids
   C. Fluid flow rates
   D. All A., B. and C.

3. In packed absorption tower, onset of flooding usually occurs at a pressure drop of about ______________ mm of water column per metre height of packing?

   A. 25-50
   B. 50-75
   C. 200-250
   D. 750-1000

4. Commercial packed scrubbers are normally designed for a pressure drop range of ______________ mm water column per metre of packed height?

   A. 4-8
   B. 17-34
   C. 52-68
   D. 88-105

5. Overall mass transfer co-efficient in case of absorption of __________ in water is based on the gas film co-efficient only, as the mass transfer process is gas film (phase) controlling ?

   A. CO2
   B. SO2
   C. NH3
   D. None of these

6. Liquid redistribution should be done in a packed tower packed with raschig rings every 6 metres or ______________ times the column diameter, whichever is lower?

   A. 2.5-3.0
   B. 5-7.5
   C. 10-12.5
   D. 15-20

7. At the following point for a given packing and set of fluids, the pressure drop per metre of packed height, with variation in fluid rates and operating pressure____________________?

   A. Increases
   B. Decreases
   C. Remain same
   D. May increase or decrease depending upon the solubility of the gas in the liquid

8. Pick out the wrong statement pertaining to the comparative evaluation of performance of the packed tower and the plate tower ?

   A. Plate tower is preferred, if interstage cooling is required to remove heats of reaction or
   solution
   B. Plate tower is preferred over packed tower, if the operation involves liquids containing
   dispersed solids
   C. The total weight of a dry plate tower is usually much more than that of a dry packed tower
   designed for the same duty
   D. In operations involving large temperature changes. (e.g. distillation), plate towers are
   preferred over packed towers as the packing may be crushed due to large temperature changes

9. Smaller sized packings are generally dumped to the packed columns, and the large ones of size greater than ______________ mm are stacked individually, which provides better control over bed porosity and offers lower gas pressure drop?

   A. 25
   B. 50
   C. 75
   D. 150

10. In actual operation of a bubble cap distillation tower, the ______________ at the bottom of the tower is more than that at the top of the tower?

    A. Molal flow rate of vapour
    B. Vapour molecular weight
    C. Pressure and temperature
    D. All A., B. and C.