In regenerative air preheater, the heat is transferred _____________________?

Related Mcqs:

1. In a recuperative air preheater, the heat is transferred____________________?

   A. from a metal wall from one medium to another
   B. from heating an itermediate material and then heating the air from this material
   C. by direct mixing ,
   D. heat is transferred by bleeding some gases from furnace
   E. none of the above

2. In designing air preheater, the important design consideration is that_________________?

   A. approach temperature should be as low as possible
   B. handling and maintenance should be easier
   C. heat transfer area should be optimum
   D. stack gases should not be cooled to the dew point
   E. none of the above

3. In water wall furnace, the heat is transferred to the water-walls by _________________?

   A. convection
   B. radiation
   C. conduction
   D. radiation and conducton
   E. radiation and convection

4. An ideal regenerative cycle is ______________________?

   A. equal to carnot cycle
   B. less than carnot cycle
   C. more than carnot cycle
   D. could be anything
   E. none of the above

5. The latent heat of steam at pressures greater than atmospheric in comparison to latent heat at atmospheric pressure is__________________?

   A. less
   B. more
   C. equal
   D. may be less or more depending on temperature
   E. unpredictable

6. The ratio of heat utilised to produce steam and the heat liberated in furnace is known as___________________?

   A. boiler effectiveness
   B. boiler evaporative capacity
   C. factor of evaporation
   D. equivalent evaporation
   E. boiler efficiency

7. Primary air is the air used to__________________?

   A. provide air around burners for obtaining optimum combustion
   B. transport and dry the coal
   C. convert CO (formed in lower zone of furnace) into C02 at higher zone
   D. air-delivered by forced draft fan
   E. none ot the above

8. Tertiary air is the air used to____________________?

   A. provide air around burners for obtaining optimum combustion
   B. transport and dry the coal
   C. cool the scanners
   D. supply air for ignitors
   E. convert CO (formed in lower zone of furnace) into C02 at higher zone

9. The specific fuel consumption for a petrol engine first decreases with increase in fuel air ratio and then increases with further increase in fuel air ratio. The minimum value occurs in the range of__________________?

   A. lean mixture
   B. chemically correct mixture
   C. rich mixture
   D. unpredictable
   E. none of the above

10. What is the weight (in lbf) of one gallon of air at 1 atm and 25˚C? The molecular mass of air is 28.97 g/mole = 0.02897 kg/mole

    A. 90 lbf
    B. 65.78 lbf
    C. 0.00989 lbf
    D. 3.00989 lbf

    Submitted by: Faheem Zaman Dhaunroo