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?

Related Mcqs:

1. 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

2. 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

3. A high vapour velocity is required for high plate efficiency in a sieve plate column. The satisfactory value of operating vapor velocity for design purpose in sieve plate column is about _______________ percent of the flooding velocity?

   A. 45
   B. 60
   C. 80
   D. 95

4. Pressure drop (Δp) and the superficial gas mass velocity (G) in case of packed absorption tower operating in the preloading range are related as_________________?

   A. Δp = G
   B. Δp = G0.5
   C. Δp = G2
   D. Δp = 1/G0.6

5. 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

6. Overall distillation column efficiency for most of the refinery columns can be given by (for μ = 0.07 – 1.4 cp and relative volatility < 4) (where ε = overall column efficiency, % μ = molal average viscosity of feed at average column temperature and pressure, cp Δp = pressure drop per tray, psi) ?

   A. η = 17 – 61.1 log μ
   B. η = 24.6 (Δp/μ)
   C. η = 1.66 – 0.25 log μ
   D. η = 0.25 log μ – 1.67

7. 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.

8. In packed towers provided with pall rings liquid redistributors are positioned at heights of every 6 metres or 5-10 times the column diameter, whichever is less. Maximum size of the pall rings should not exceed _______________________ of the column diameter?

   A. 1/10-1/15th
   B. 1/5-1/10th
   C. 1/20-1/30th
   D. 1/2 to 1/4th

9. 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

10. Vapor velocity in a distillation column for non-foaming mixture is in the range of ______________ times the flooding velocity?

    A. 0.1 to 0.3
    B. 0.6 to 0.7
    C. 0.85 to 0.95
    D. 1.5 to 2