Diameter to height ratio for a raschig ring is_____________________?

Related Mcqs:

1. Raschig ring made of porcelain cannot be used for treating concentrated___________________?

   A. Hydrochloric acid
   B. Nitric acid
   C. Alkalis
   D. Sulphuric acid

2. Diameter of raschig rings used in packed tower in industry is normally around _____________________ inches?

   A. 2
   B. 8
   C. 12
   D. 18

3. In a moderately sized packed absorption tower, channelling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter ?

   A. > 4 :1
   B. < 8 : 1
   C. > 8:1
   D. < 6:1

4. Use of raschig rings in place of crushed stones as packing in packed beds (other things being same) ?

   A. Increases pressure drop, increases surface area
   B. Increases pressure drop, decreases surface area
   C. Decreases pressure drop, increases surface area
   D. Decreases pressure drop, decreases surface area

5. H2S is being absorbed in a gas absorber unit. The height of the transfer unit based on the overall mass transfer coefficient on the gas side is 0.4 m. The equilibrium data is given by, y = 1.5 x. The bulk concentration of H2S has to be reduced from 0.05 to 0.001 mole fraction in the gas side. The height of the tower (in meters) corresponding to an operating line given by, y = 5x + 0.001 is ______________________?

   A. 2.0
   B. 1.56
   C. 1.0
   D. 0.56

6. In a packed tower, the value of HETP equals HTUOG, when the equilibrium and the operating lines are (where, HETP = height equivalent to a theoretical plate HTUOG = overall gas phase height of a transfer unit) ?

   A. Straight
   B. Parallel
   C. Both A. & B.
   D. Neither A. nor B.

7. The slope of the operating line for a single component co-current absorber when plotted in terms of mole ratio units is_____________________?

   A. 0
   B. ∞
   C. -ve
   D. +ve

8. Which of the following same diameter columns gives lowest pressure drop per unit height ?

   A. Bubble-cap column
   B. Sieve-plate column
   C. Packed column (stacked)
   D. Randomly packed column

9. If Rm is the minimum reflux ratio, the optimum reflux ratio may be around _________________ Rm ?

   A. 1.2 to 1.5
   B. 2.5 to 3
   C. 3 to 4
   D. 5

10. In continuous distillation, the internal reflux ratio (Ri) and the external reflux ratio (Re) are related as_____________________?

    A. Ri = Re/(1 – Re)
    B. Ri = (1 – Re)/Re
    C. Ri = Re
    D. Ri = Re/(1 + Re)