Fouling factor must be included in the calculation of overall design heat transfer coefficient, when the liquid__________________?

Related Mcqs:

1. Factor of safety (i.e., overdesign factor) in heat transfer equipments is about _____________ percent more than the actual/theoretical design factor?

   A. 5-10
   B. 15-20
   C. 30-35
   D. 35-40

2. The design stress, which is more than the damaging stress, is the least unit stress that will render a member unfit for service before the end of its normal life. The design stress factor or factor of safety indicates the margin between design stress and the _______________ stress?

   A. Working
   B. Damaging
   C. Allowable
   D. None of these

3. For annular flow of a fluid, the ratio of the equivalent diameter for pressure drop calculation to the equivalent diameter for heat transfer calculation is_________________?

   A. d1/(d1 + d2)
   B. d2/(d1 + d2)
   C. (d1 + d2)/d1
   D. (d1 + d2)/d2

4. 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

5. In case of a shell and tube heat exchanger, the effect of L/D on inside film heat transfer coefficient (hi) vanishes after a Reynold number of_____________?

   A. 1000
   B. 3000
   C. 5000
   D. 10000

6. The value of fouling factor depends upon the__________________?

   A. Characteristic of process fluid
   B. Velocity of process fluid containing suspended solids
   C. Suspended solids in the fluid
   D. All A., B. and C.

7. Equivalent diameter for heat transfer calculation for a duct of square cross-section having each side as ‘d’ will be__________________?

   A. d
   B. √d
   C. √(2πd)
   D. √(2d)

8. Overall mass transfer co-efficient in case of absorption of __________ in water is based on the gas film co-efficient only, as the mass transfer process is gas film (phase) controlling ?

   A. CO2
   B. SO2
   C. NH3
   D. None of these

9. Steam side heat transfer co-efficient for design consideration under ordinary condition can be assumed to be about _____________ kcal/hr.m2.°C?

   A. 1250
   B. 2500
   C. 7500
   D. 15000

10. It is not desirable to design a heat exchanger for LMTD correction factor, FT, of less than _________________?

    A. 0.99
    B. 0.95
    C. 0.80
    D. 0.55