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

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. 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. 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

4. 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

5. 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

6. 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.

7. 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

8. In case of saddle packing (e.g., berl and intralox saddles), the maximum size of the packing should not exceed ______________ of the column diameter?

   A. 1/5th
   B. 1/15th
   C. 1/30th
   D. 1/50th

9. Height equivalent to a theoretical plate (HETP) is the height of packing that will give the same separation as one theoretical plate in gas-liquid mass transfer operations like distillation, absorption/stripping and humidification/dehumidification. HETP which is experimentally determined, depends upon the_______________?

   A. Flow rates of each fluid
   B. Type and size of packing
   C. Concentration of each fluid
   D. All A, B. & C.

10. The difficulty of liquid distribution in packed towers is accentuated, when the ratio of tower diameter to packing diameter is_________________?

    A. < 30
    B. < 7
    C. > 7 20 < 50