The separation of liquid droplets from the vapor is done by a/an _____________ in the evaporators?

Related Mcqs:

1. 1000 Kg of liquid at 30°C in a well stirred vessel has to be heated to 120°C, using immersed coils carrying condensing steam at 150°C. The area of the steam coils is 1.2 m2 and the overall heat transfer co-efficient to the liquid is 1500 W/m2.°C. Assuming negligible heat loss to the surrounding and specific heat capacity of the liquid to be 4 kJ/kg.°C, the time taken for the liquid to reach desired temperature will be__________________?

   A. 15 min
   B. 22 min
   C. 44 min
   D. 51 min

2. In case of evaporators, liquid entrainment results primarily due to_________________?

   A. High vacuum in the evaporator
   B. High evaporation rate
   C. Foaming of the solution
   D. High heat transfer rate

3. The type of liquor circulation system to be ‘ employed in evaporators (viz. natural or forced circulation) is determined mainly by the ______________ of the liquid?

   A. Viscosity
   B. Density
   C. Thermal conductivity
   D. Corrosive nature

4. The film co-efficient is decreased due to the presence of non-condensing gases in the vapors. The film co-efficient of superheated vapor as compared to that of saturated vapor is___________________?

   A. More
   B. Less
   C. Some
   D. Either more or less; depends on the nature of vapor

5. If air (a non-condensing gas) is present in a condensing vapor stream, it will ______________ the condensation rate of vapor?

   A. Increase
   B. Decrease
   C. Not affect
   D. Increase the condensing film co-efficient as well as

6. Viscous & heat sensitive liquids are concentrated in _____________ evaporators?

   A. Open pan
   B. Long tube
   C. Agitated film
   D. None of these

7. Which of the following accessories is provided in the vapor line of an evaporator for removing the entrained liquid ?

   A. Bleed point
   B. Vent
   C. Catchall
   D. Baffle

8. Open pan evaporators are preferred to be used, when the solution to be concentrated is_________________?

   A. Scaling
   B. Highly viscous
   C. Corrosive
   D. Salty

9. In evaporators, lowering the feed temperature_______________?

   A. Increases the heating area required
   B. Reduces the economy
   C. Both A. and B.
   D. Decreases the heating area required

10. The advantage of backward feed multiple effect evaporators over forward feed units is that___________________?

    A. Heat sensitive material can be handled
    B. There is no additional cost of pumping
    C. Most concentrated liquid is at highest temperature
    D. Equal heat transfer co-efficients exist in various effects