To get high tray efficiency___________________?

Related Mcqs:

1. To get high tray efficiency___________________?

   A. Interfacial surface between liquid and gas phase should be large
   B. Time of contact between the two phases should be less
   C. Gas velocity should be very low
   D. Liquid entrainment should be severe

2. Flooding in a vapor-liquid contacting equipment occurs in a tray, when the pressure drop through a tray is _______________ the liquid head available in the downcomer?

   A. Less than
   B. More than
   C. Same as
   D. Very much less

3. In a gas-liquid absorption column, for obtaining the maximum absorption efficiency___________________?

   A. Liquid stream should be distributed uniformly
   B. Gas stream should be distributed uniformly
   C. Both gas as well as liquid streams should be distributed uniformly
   D. By passing should be completely avoided

4. An aqueous solution of methanol is to be distilled in a tray column. High pressure steam is available as a source of heat. For a given reflux ratio and overhead composition, two options are being explored; (i) a reboiler is used and (ii) no reboiler is used but steam is fed directly to the bottom of the column. As compared to option (i), in option (ii) ____________________?

   A. Less number of trays are required
   B. Composition of the residue remains unchanged
   C. More number of trays are required but the residue composition remains unchanged
   D. More number of trays are required and the residue composition is more dilute in methanol

5. In distillation columns, the number of bubble caps per tray primarily depends upon the_______________________?

   A. Allowable liquid velocity
   B. Allowable gas velocity
   C. Allowable gas and liquid velocities
   D. Feed composition

6. Batch tray dryers suffers from the disadvantage of______________________?

   A. High maintenance cost
   B. Non-uniform & low production rate
   C. High labour cost & low heat economy
   D. All ‘a’, ‘b’ & ‘c’

7. Tray spacing in a distillation column of dia 10-12 ft. used in petroleum refinery may be around _____________ inches?

   A. 5
   B. 30
   C. 60
   D. 100

8. When the mixture to be distilled has a very high boiling point and the product material is heat sensitive, the separation technique to be used is _______________ distillation?

   A. Continuous
   B. Steam
   C. Azeotropic
   D. None of these

9. High pressure at the bottom of a distillation tower handling heat sensitive materials results in _____________________?

   A. Thermal decomposition of bottoms
   B. Increased relative volatility
   C. Erosion of the tower
   D. Very efficient operation

10. For absorbers, high pressure drop results in___________________?

    A. Increased efficiency
    B. Decreased efficiency
    C. High operating cost
    D. Better gas liquid contact