2407. Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above __________ °C, because corrosion prevails at higher temperatures.
350
750
1050
1250
✅ The correct answer is option B.
2412. An example of indirectly heated furnace is the
Soaking pit
Muffle furnace
Reheating furnace
None of these
✅ The correct answer is option B.
2377. Scaling of furnace stock is reduced by __________ in flue gas.
CO
H₂
High CO/CO₂
All of the above
✅ The correct answer is option D.
2382. In order to maintain a reducing atmosphere in a furnace, it should have
No O₂ in flue gas
CO in flue gas
High excess air
None of these
✅ The correct answer is option B.
2387. Advantages of use of preheated combustion air are
Saving in fuel consumption
Reduction in scale losses
Increase in flame temperature
All of the above
✅ The correct answer is option D.
2392. Neutral atmosphere is maintained in a/an __________ furnace.
Cold rolled steel coil annealing
Open hearth
Soaking pit
Walking beam reheating
✅ The correct answer is option A.
2398. The resistance furnace produces heat by the
Electric arc struck between electrodes and the charge
Flow of current through a heating element
Combination of induced current and skin effect
None of these
✅ The correct answer is option B.
2403. In a heating process, a heat flow diagram in which the quantities of heat in the various items of a heat balance are represented by the width of a band is called the
Ostwald chart
Cox chart
Sankey diagram
None of these
✅ The correct answer is option C.
2408. Which of the following variables affects the furnace capacity?
Temperature of flue gas
Thermal conductivity of stock
Thickness of heating stock
All of the above
✅ The correct answer is option D.
2413. 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.