101. Thermal efficiency of a limestone calcination rotary kiln may be around __________ percent.
20
40
65
80
✅ The correct answer is option B.
Furnace Technology MCQs
102. The electric furnace in which heat is produced by a combination of induced current and skin effect is called __________ furnace.
Arc
Resistance
Low frequency induction
High frequency induction
✅ The correct answer is option D.
103. Which of the following is a rotary furnace?
Lime kiln
Soaking pit
Stoves
Annealing furnace
✅ The correct answer is option A.
104. Overfire burning in a furnace is a phenomenon characterised by
Supply of excess fuel
Supply of excess air
Burning carbon monoxide and other incombustible in upper zone of furnace by supplying more air
None of these
✅ The correct answer is option C.
105. Combustion of fuel in a furnace with oxygen enriched air results in higher
Flue gas volume
Flame temperature
Fuel consumption
Stack loss
✅ The correct answer is option B.
106. Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about __________ percent.
< 2
< 5
< 8
< 10
✅ The correct answer is option A.
107. In salt bath furnace, heat is transferred to the charge mainly by
Conduction
Convection
Radiation
None of these
✅ The correct answer is option A.
108. Fuel economy in an industrial furnace operation can not be achieved by the use of
Stoichiometric combustion air
Non-preheated combustion air
Combustion air not enriched with oxygen
Recupterators
✅ The correct answer is option A.
109. An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called __________ furnace.
Resistance
Arc
Low frequency induction
None of these
✅ The correct answer is option B.
110. Which is the most thermally efficient furnace?
Reheating furnace
Reverberatory furnace
Rotary kilns
Boiler furnace
✅ The correct answer is option D.