If all the conditions and dimensions are same, then the ratio of velocity through the tubes of a double pass heat exchanger to that through the single pass heat exchanger is_________________?

Related Mcqs:

1. LMTD correction factor which is to be applied for a cross-flow heat exchanger increases with increase in the number of shell passes. Its value for a single pass cross flow heat exchanger is __________________?

   A. 0
   B. 1
   C. > 1
   D. < 1

2. 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. 20.5

3. Air is to be heated by condensing steam. Two heat exchangers are available (i) a shell and tube heat exchanger and (ii) a finned tube heat exchanger. Tube side heat transfer area are equal in both the cases. The recommended arrangement is________________?

   A. Finned tube heat exchanger with air inside and steam outside
   B. Finned tube heat exchanger with air outside and steam inside
   C. Shell and tube heat exchanger with air inside tubes and steam on shell side
   D. Shell and tube heat exchanger with air on shell side and steam inside tubes

4. If a single tube pass heat exchanger is converted to two pass, then for the same flow rate, the pressure drop per unit length in tube side will ________________?

   A. Increase by 1.8 times
   B. Decrease by 22
   C. Increase by 216
   D. Remain unchanged

5. In a shell and tube heat exchanger, putting a longitudinal baffle across the shell, forces the shell side fluid to pass _____________ through the heat exchanger ?

   A. Once
   B. Twice
   C. Thrice
   D. Four times

6. A fluid is flowing inside the inner tube of a double pipe heat exchanger with diameter ‘d’. For a fixed mass flow rate, the tube side heat transfer co-efficient for turbulent flow conditions is proportional to_____________________?

   A. d0.8
   B. d-0.2
   C. d-1
   D. d-1.8

7. The advantage of using a 1 – 2 shell and tube heat exchanger over a 1 – 1 shell and tube heat exchanger is_________________?

   A. Lower tube side pressure drop
   B. Lower shell side pressure drop
   C. Higher tube side heat transfer co-efficient
   D. Higher shell side heat transfer co-efficient

8. Maximum water velocity in tubes of a 1-2 shell and tube heat exchanger may be around _____________ metres/second?

   A. 1
   B. 10
   C. 20
   D. 30

9. In a co-current double pipe heat exchanger used for condensing saturated steam over the inner tube, if the entrance and exit conditions of the coolant are interchanged, then the rate of condensation will___________________?

   A. Increase
   B. Decrease
   C. Remain unchanged
   D. Either increase or decrease; depends on the coolant flow rate

10. For the same heat transfer area and the terminal conditions, the ratio of the capacities of a single effect evaporator to a triple effect evaporator is_________________?

    A. 3
    B. 0.33
    C. 1
    D. 1.33