Reflux ratio variation in a distillation column is between___________________?

Related Mcqs:

1. 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

2. Optimum reflux ratio in a continuous distillation column is determined by the__________________?

   A. Maximum permissible vapour velocity
   B. Flooding limit of the column
   C. Total cost consideration (fixed cost of the column plus the cooling water & steam cost)
   D. None of these

3. The slope of operating line in the rectifying section of a distillation column is unity, if the reflux ratio is___________________?

   A. 0
   B. ∞
   C. 1
   D. Minimum

4. In case of a continuous distillation column, increase in reflux ratio may result in the______________?

   A. Lower fixed charges for the column
   B. Greater cost for the reboiler heat supply
   C. Greater cost for the condenser coolant
   D. All A., B. and C.

5. With increase in the reflux ratio for a fixed production from a continuous binary distillation column, the ______________________ decreases?

   A. Fixed charges initially
   B. Running cost of cooling water for condenser
   C. Vapour & liquid load both
   D. Running cost of steam for reboiler

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. Overall tray efficiency of a distillation column is the ratio of the number of ___________________?

   A. Overall gas transfer units to the number of ideal trays required
   B. Ideal trays required to the number of real trays required
   C. Real trays required to the number of ideal trays required
   D. None of these

8. Bubble cap tray is the most commonly used tray in large distillation column, because______________?

   A. Of its flexibility and nearly constant efficiency under varying conditions of operation
   B. It incurs less pressure drop as compared to any other try designed for the same duty
   C. It eliminates the foaming and entrainment tendency during operation
   D. None of these

9. The minimum tray spacing in distillation column of diameter less than 3 ft is normally _____________ inches?

   A. 6
   B. 18
   C. 24
   D. 34

10. What is the slope of the operating line in the stripping section of a distillation column ?

    A. 0
    B. ∞
    C. > 1
    D. < 1