61. Tunnel kilns are usually used for
Roasting of pyrites
Drying/tempering of refractories
Reheating of slabs
Melting of glass
✅ The correct answer is option B.
Furnace Technology MCQs
62. Which one shows the diagramatic heat balance in a furnace?
Sankey diagram
Cox chart
Ostwald chart
None of these
✅ The correct answer is option A.
63. Fuel economy in furnaces can be achieved by
Using oxygen enriched combustion air
Preheating the combustion air
Reducing the heat loss through furnace openings & doors
All of the above
✅ The correct answer is option D.
64. Test specimen for determination of refractoriness under load (RUL) of a refractory is heated in a
Furnace employing neutral atmosphere
Carbon resistance furnace
Reducing atmosphere
Furnace employing negative pressure
✅ The correct answer is option B.
65. Thermal efficiency of furnaces can be improved by
Waste heat recovery from flue gas
Minimising heat losses from furnace walls
Maintaining proper draught
All of the above
✅ The correct answer is option D.
66. Which of the following is a natural draft furnace?
Blast furnace stoves
Power plant boilers
Sintering furnace
None of these
✅ The correct answer is option A.
67. Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the
Physical nature, ash content and fineness of the coal
Amount of excess air supplied and load on the boiler
Type of burner and combustion chamber
All of the above
✅ The correct answer is option D.
68. Rotary kilns are used in the
Calcination of limestone & dolomite
Cement manufacture
Both A and B
Neither A nor B
✅ The correct answer is option C.
69. Reducing atmosphere is maintained in a
Calcination kiln
Blast furnace
Soaking pit
L.converter
✅ The correct answer is option B.
70. In practical operation of any furnace, zero oxygen percentage or theoretical CO₂ percentage in flue gas is rarely achieved, because of
Use of non-preheated combustion air
Use of pulverised solid fuels
Imperfect mixing of fuel & air and infiltration of air
Use of excessive positive draft in the furnace
✅ The correct answer is option C.