Related Mcqs:

1. 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

2. 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

3. 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

4. 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

5. What is the value of ‘q’ for saturated vapor feed to a distillation column? (where q = fraction of the feed stream that is liquid ?

   A. 0
   B. 1
   C. 1

6. In a distillation column, bubble caps are located on trays with a pitch of ______________ times the outside diameter of the caps?

   A. 1.3 to 2
   B. 1.6 to 2
   C. 2.5
   D. 1.5 to 3

7. In a continuous distillation column, the optimum reflux ratio ranges from _______________ times the minimum reflux ratio?

   A. 1.1 to 1.5
   B. 1.6 to 2
   C. 2.2 to 2.6
   D. 2.7 to 3

8. Multiple blade paddle agitator is used for mixing high viscosity liquids/paste in which the paddle diameter is commonly 0.8 times the tank diameter. However, the width of the blade is in the range of ______________ times the paddle diameter?

   A. 0.1 to 0.25
   B. 0.3 to 0.5
   C. 0.5 to 0.6
   D. 0.65 to 0.80

9. 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

10. In a distillation column, minimum clearance to be maintained between the overflow weir and the last row of the bubble caps is ______________ cms?

    A. 2.5
    B. 7.5
    C. 15
    D. 20