Which of the following is not an additive for flue gases from furnace to reduce its dewpoint ?

Related Mcqs:

1. Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percent furnace oil as compared to its combustion with atmospheric air, if the flue gas outlet temperature from the soaking pit is 1200°C ?

   A. 5
   B. 60
   C. 20
   D. 40

2. In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the__________________?

   A. Rate of firing and emissivity of flame
   B. Thermal conductivity of the charge & structural materials of furnace
   C. Nature of process; whether batch, continuous or intermittent
   D. All A., B. and C.

3. Which furnace employs an I.D. fan for the removal of flue gases from the furnace ?

   A. Coke oven
   B. Blast furnace stoves
   C. Beehive coke oven
   D. High pressure boiler

4. Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace ?

   A. Economiser
   B. Regenerator
   C. Ceramic recuperator
   D. Waste heat boiler

5. To reduce the stack loss, heat recovery from flue gas can be done by_____________________?

   A. Preheating of cold stock
   B. Preheating of combustion air
   C. Steam generation in waste heat boilers
   D. All A., B. and C.

6. Out of the following fuels used in a furnace exhausting flue gas at a temperature of 600°C, the percentage stack loss will be maximum in case of complete combustion of_________________?

   A. Furnace oil with air
   B. Furnace oil with oxygen
   C. Blast furnace gas with air
   D. Blast furnace gas with oxygen

7. Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an_________________?

   A. Economiser
   B. Steam superheater
   C. Air preheater
   D. All A., B. and C.

8. Scaling of furnace stock is reduced by _______________ in flue gas?

   A. CO
   B. H2
   C. High CO/CO2
   D. All A., B. & C.

9. Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about _____________ percent?

   A. < 2
   B. < 5
   C. < 8
   D. < 10

10. In practical operation of any furnace, zero oxygen percentage or theoretical CO2 percentage in flue gas is rarely achieved, because of__________________?

    A. Use of non-preheated combustion air
    B. Use of pulverised solid fuels
    C. Imperfect mixing of fuel & air and infiltration of air
    D. Use of excessive positive draft in the furnace