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?

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, 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

3. 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

4. The shell side pressure drop in a shell and tube heat exchanger is maximum for _______________ baffle?

   A. Disk and ring
   B. Segmental
   C. Orifice
   D. Independent of the type of

5. A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co-efficient for air will vary in the ratio of_________________?

   A. 2
   B. 20.8
   C. 20.2
   D. None of these

6. In a shell and tube heat exchanger having square pitch, the shell side equivalent diameter is given by (where, P = pitch, d = outside diameter of the tube) ?

   A. 4(P2 – πd2/4)/πd
   B. (P2 – rd2/4)/rd
   C. 4P2/πd
   D. πd/4P2

7. In a shell and tube heat exchanger, tube side _______________ of the mass velocity?

   A. Heat transfer co-efficient is proportional to 0.8th power
   B. Pressure drop is proportional to the square
   C. Both A. & B.
   D. Neither A. nor B.

8. The ratio of tube length to shell diameter in case of liquid shell and tube heat exchanger ranges from__________________?

   A. 2 to 3
   B. 3 to 5
   C. 4 to 8
   D. 6 to 12

9. Ratio of tube length to shell diameter for a shell and tube heat exchanger is________________?

   A. 8 : 1 to 12 : 1 for both liquid-liquid and gas-gas heat exchangers
   B. 4 : 1 to 8 : 1 for liquid-liquid exchanger
   C. < 4 : 1 for gas-gas exchangers
   D. Both B. & C.

10. Minimum tube pitch recommended for shell and tube heat exchangers is about _______________ times the outside diameter of the tube?

    A. 1.25
    B. 1.75
    C. 2.5
    D. 3.5