An equipment which converts the latent or sensible heat of one fluid into the latent heat of vaporisation of another, is called a_________________?

Related Mcqs:

1. It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is____________________?

   A. 3.06 × 105
   B. 6.12 × 105
   C. 7.24 × 105
   D. 9.08 × 105

2. For a laminar flow of fluid in a circular tube, ‘h1’ is the convective heat transfer co-efficient at velocity ‘V1’. If the velocity is reduced by half and assuming the fluid properties are constant, the new convective heat transfer co-efficient is________________?

   A. 1.26 h1
   B. 0.794 h1
   C. 0.574 h1
   D. 1.741 h1

3. Sensible heat absorbed by 1 lb of water when it is heated from 32 to 212°F may be around ______________ BTU?

   A. 180
   B. 970
   C. 3.97
   D. Data insufficient, can’t be predicted

4. Sensible heat of hot industrial flue gases cannot be recovered by a/an________________?

   A. Economiser
   B. Regenerator
   C. Ceramic recuperator
   D. None of these

5. 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

6. A 10 cm dia steam pipe, carrying steam at 180°C, is covered with an insulation (conductivity = 0.6 W/m.°C). It losses heat to the surroundings at 30°C. Assume a heat transfer co-efficient of 0.8 W/m2.°C for heat transfer from surface to the surroundings. Neglect wall resistance of the pipe and film resistance of steam. If the insulation thickness is 2 cms, the rate of heat loss from this insulated pipe will be__________________?

   A. Greater than that for un-insulated steam pipe
   B. Less than that of the un-insulated steam pipe
   C. Equal to that of the un-insulated steam pipe
   D. Less than the steam pipe with 5 cms insulation

7. Extended heat transfer surface like fins are used to increase the heat transfer rate. Fin efficiency is defined as the ratio of heat transferred across the fin surface to the theoretical heat transfer across an equal area held at the________________?

   A. Surrounding temperature
   B. Average temperature of the fin
   C. Temperature of the fin end
   D. Constant temperature equal to that of the base

8. Latent heat absorbed by 1 lb of water at 212°F, when it is changed to steam at 212°F, may be around ______________ BTU?

   A. 180
   B. 970
   C. 3.97
   D. None of these

9. Rate of heat transfer by vaporisation from pools of water is affected by the ____________________?

   A. Nature of heating surface and distribution of bubbles
   B. Surface tension of water
   C. Viscosity of water
   D. All A., B. and C.

10. Mode of heat transfer in which the fluid moves under the influence of changes in fluid pressure produced by external work is called_______________?

    A. Radiation
    B. Natural convection
    C. Forced convection
    D. Conduction