121. __________ atmosphere is maintained inside an iron blast furnace.
Oxidising
Reducing
Inert
Decarburising
✅ The correct answer is option B.
Furnace Technology MCQs
122. Flue gas outlet temperature from the chimney of any furnace should be ideally about __________ °C.
50
100
150
250
✅ The correct answer is option C.
123. Which of the following furnaces will have maximum thermal efficiency?
Soaking pits
Walking beam reheating furnace
Boiler furnace
Rotary kilns
✅ The correct answer is option C.
124. In reverberatory furnace, charge is heated mainly by
Conduction
Natural convection
Radiation of heat from the roof of the combustion chamber
None of these
✅ The correct answer is option C.
125. Circulation of gases in furnace is caused by the
Change in volume during a change of temperature
Difference in density between hot and cold gases
Furnace pressure in conjunction with draft in flues
All of the above
✅ The correct answer is option D.
126. Hearth furnaces are not used for
Roasting
Melting
Reheating
None of these
✅ The correct answer is option D.
127. Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of
Graphite powder
Thoria
Zircon powder
Beryllium
✅ The correct answer is option C.
128. Pulverised fuel fired furnaces employ __________ fuel firing.
Horizontal
Vertical
Tangential
All of the above
✅ The correct answer is option D.
129. Means for giving direction to the circulation of gases in furnaces are
Fans
Arrangement of heating stock in the furnaces
Location of outlet ports and heating & combustion devices
All of the above
✅ The correct answer is option D.
130. The thermal efficiency of an air/fuel gas preheating recuperator may be as high as __________ percent.
50
65
85
99
✅ The correct answer is option C.