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 ?

Related Mcqs:

1. 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

2. In a shell and tube heat exchanger for a given heat transfer surface area, smaller diameter tubes are favoured as compared to larger diameter ones; because the smaller diameter tubes ______________?

   A. Are easier to clean
   B. Are less prone to fouling
   C. Can be fitted into a smaller shell diameter hence the cost of the heat exchanger would be less
   D. None of these

3. In case of 1.5″ heat exchanger tubes, the inside flow area _____________ with decrease in BWG?

   A. Increases
   B. Decreases
   C. Remains same
   D. None of these

4. 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

5. In a shell and tube heat exchanger, the overall heat transfer co-efficient is proportional to the tube side (volumetric flow rate)0.8. This is valid, only when the ratio of the tube side film resistance to the total resistance is almost equal to____________________?

   A. ∞
   B. 1
   C. 20.8
   D. 2

6. Tube side heat transfer co-efficient for turbulent flow of liquid through tubes is proportional to___________________?

   A. G0.2
   B. G0.5
   C. G0.8
   D. G1.5

7. In a shell and tube heat exchanger, the shortest centre to centre distance between the adjacent tubes is__________________?

   A. Called tube pitch
   B. Called tube clearance
   C. Always less than the diameter of the tube
   D. None of these

8. The clearance between two tubes in a shell and tube heat exchanger is known as ‘ligament’, whose minimum value is _____________ the outside diameter of the tube, but in no case it should be less than 4.5 mm?

   A. Equal to
   B. Half
   C. One fourth
   D. Three fourth

9. Which of the following lengths of heat exchanger tubes are normally not used in practice ?

   A. 2.5 metres
   B. 6 metres
   C. 10 metres
   D. 0.5 metre

10. 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