In a multiple effect evaporator system having ‘n’ effects, the amount of water evaporated per unit surface area in approximately equal to _____________ times that in a single effect?

Related Mcqs:

1. Steam economy is defined as the amount of evaporation per unit amount of steam used, while the capacity is the total evaporation obtained per hour. Use of multiple effects in evaporation ?

   A. Increases capacity
   B. Increases economy
   C. Does not affect the capacity
   D. Both B. & C.

2. If a single tube pass heat exchanger is converted to two passes; for the same flow rate, the pressure drop per unit length in tube side will _____________ times?

   A. Increase by 1.8
   B. Decrease by 22
   C. Increase by 21.6
   D. None of these

3. 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

4. In a pressure vessel containing multiple openings of various dimensions at different parts, stress concentration at the edges of the opening is maximum which becomes negligibly small beyond the area covered by ______________ times the hole diameter?

   A. Two
   B. Five
   C. Ten
   D. Twenty

5. Number of evaporators which can be used in service in a multiple effect evaporation system is limited by the__________________?

   A. Practical limit reached, due to low heat transfer rate because of inadequate temperature
   difference
   B. Economic limit reached, when the plant cost exceeds the saving of steam
   C. Both A. & B.
   D. Neither A. nor B.

6. In common bubble cap distillation column design practice, riser area is approximately equal to (where, Aa = Annular passage area, and Sa = Slot area) ?

   A. Aa = Sa
   B. 1.2 Aa = 1.2 Sa
   C. Sa = 1.5 Aa
   D. Aa = 1.5 Sa

7. Tube side pressure drop in a 1-2 heat exchanger (for turbulent flow of fluids through the tubes) is about __________ times, that in a 1-1 heat exchanger having the same size & number of tubes and operated at the same liquid flow rate ?

   A. 2
   B. ½
   C. 4
   D. 8

8. The average velocity in the tubes of a 1-4 heat exchanger is ______________ times that in 1-1 heat exchanger having the same size & number of tubes and operated at same liquid flow rate ?

   A. 2
   B. 1/2
   C. 4
   D. 1/4

9. Heat transfer co-efficient, hG(Kcal/hr.m2 .°C) and mass velocity of air, G (kg/hr.m2 ) for air flow parallel to the surface in case of constant drying rate in batch drying is related as hG = 0.0176G0.8. But when the flow of air perpendicular to the surface is encountered, this equation changes to ____________________?

   A. hG = 1.004G0.37
   B. 1.004G0.8
   C. hG = 0.0176G0.37
   D. 0.0176G1.37

10. With increase in gas flow rate to fabric surface area ratio (Nm3/hr/m2 fabric surface area), the size & the cost of a bag filter___________________?

    A. Increases
    B. Decreases
    C. Remain unaffected
    D. None of these