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

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. 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

3. Fuel economy in an industrial furnace operation cannot be achieved by the use of__________________?

   A. Stoichiometric combustion air
   B. Non-preheated combustion air
   C. Combustion air not enriched with oxygen
   D. Recuperators

4. Higher furnace temperature cannot be achieved by use of a lean fuel gas in the furnace by_________________?

   A. Increasing the draft in the furnace
   B. Preheating the fuel gas
   C. Oxygen enrichment of combustion air
   D. Preheating the combustion air

5. 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

6. 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.

7. 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

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. Flue gas outlet temperature from the chimney of any furnace should be ideally about ______________ °C?

   A. 50
   B. 100
   C. 150
   D. 250

10. Protective gas used in the annealing furnace for steel coil comprises of__________________?

    A. 95% N2 + 5% H2
    B. 5% H2 + 9% N2
    C. 100% CO
    D. 100% H2