Accelerating the rate of scaling
Causing metal embrittlement
Attacking the grain boundaries; particularly severe on low carbon and nickel bearing steels at high temperature
All of the above
✅ The correct answer is option D.
Furnace Technology MCQs
12. In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the
Rate of firing and emissivity of flame
Thermal conductivity of the charge & structural materials of furnace
Nature of process ; whether batch, continuous or intermittant
All of the above
✅ The correct answer is option D.
13. In furnaces operating at very high temperature (say) 1250°C, e.g. soaking pit), the maximum heat transfer takes place by
Conduction
Convection
Radiation
Can not be predicted
✅ The correct answer is option C.
14. Artificial draught produced by a fan in the furnace can be controlled by the
Speed of the fan
Damper
Variation in the pitch of fan blades
All of the above
✅ The correct answer is option D.
15. Low stack loss indicates the
Use of sub-stoichiometric air for combustion
Efficient use of fuel
Inefficient use of fuel
Oxygen enrichment of combustion air
✅ The correct answer is option B.
16. Heat transfer rate to the stock/charge in the furnace does not depend upon the
Emissivity of the refactory walls
Size of the furance
Use of waste heat recovery equipments
Thickness of the stock
✅ The correct answer is option C.
17. The heat recoverable from flue gases of furnaces depends on the
Thermal efficiency of furnace
Quantity of flue gases
Flue gas temperature drop through the furnace
All of the above
✅ The correct answer is option D.
18. Which is a continuous furnace?
Coke ovens
Annealing furnace
Glass tank furnace
None of these
✅ The correct answer is option C.
19. Which one is not an induced draught furnace?
Blast furnace stove
Sintering furnace
High pressure boiler
None of these
✅ The correct answer is option A.
20. The advantages of firing pulverised coal in the furnace lies in the fact that, it
Permits the use of high ash content coal
Permits the use of low fusion point ash coal
Accelerates the burning rate and economises on fuel consumption
All of the above
✅ The correct answer is option C.