Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about ____________ °C?
A. 80
B. 130
C. 180
D. 250
Furnace Technology
Protective gas used in the annealing furnace for steel coil comprises of__________________?
Protective gas used in the annealing furnace for steel coil comprises of__________________?
A. 95% N2 + 5% H2
B. 5% H2 + 9% N2
C. 100% CO
D. 100% H2
Artificial draught produced by a fan in the furnace can be controlled by the___________________?
Artificial draught produced by a fan in the furnace can be controlled by the___________________?
A. Speed of the fan
B. Damper
C. Variation in the pitch of fan blades
D. All A., B. and C.
Which of the following is the most suitable for preheating combustion air above 650°C ?
Which of the following is the most suitable for preheating combustion air above 650°C ?
A. Regenerator
B. Metallic recuperator
C. Ceramic recuperator
D. None of these
The electric furnace in which heat is produced by a combination of induced current and skin effect is called _____________ furnace?
The electric furnace in which heat is produced by a combination of induced current and skin effect is called _____________ furnace?
A. Arc
B. Resistance
C. Low frequency induction
D. High frequency induction
Thermal efficiency of an open hearth furnace may be about _____________ percent?
Thermal efficiency of an open hearth furnace may be about _____________ percent?
A. 5
B. 20
C. 50
D. 80
Which of the following is not a directly fired furnace ?
Which of the following is not a directly fired furnace ?
A. By-product coke oven
B. Calcination kiln
C. Sintering furnace
D. Open hearth furnace
Air filtration in a furnace___________________?
Air filtration in a furnace___________________?
A. Reduces its thermal efficiency
B. Is indicated by flame sting out
C. Increases the flue gas temperature
D. None of these
Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above _____________ °C?
Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above _____________ °C?
A. 250
B. 650
C. 850
D. 1000
Regenerators are used for waste heat recovery in____________________?
Regenerators are used for waste heat recovery in____________________?
A. By-product coke ovens
B. Beehive coke oven
C. Blast furnace stoves
D. Soaking pits