Oxygen content in a flue gas was found to be 4%. It implies that excess air used for combustion was around ______________ percent?
A. 4
B. 96
C. 20
D. 40
Fuels and Combustion
Sulphur in metallurgical coal__________________?
Sulphur in metallurgical coal__________________?
A. Contributes to its heating value
B. Affects the quality of steel produced as cracks develop on the surface while rolling the steel
C. Both A. and B.
D. Neither A. nor B.
Fusion point of coal ash increases with increase in its ____________ content?
Fusion point of coal ash increases with increase in its ____________ content?
A. Iron sulphate
B. Iron silicate
C. Lime and magnesia
D. All A., B. and C.
Calorific value of coke oven gas is around ______________ Kcal/Nm3?
Calorific value of coke oven gas is around ______________ Kcal/Nm3?
A. 900
B. 4200
C. 7500
D. 2000
Caking index of coal blend used for blast furnace coke making is about_________________?
Caking index of coal blend used for blast furnace coke making is about_________________?
A. 8
B. 12
C. 22
D. 36
A coal with high ash content___________________?
A coal with high ash content___________________?
A. Has higher calorific value
B. Is harder and stronger
C. Is not subjected to washing
D. Has low quantity of mineral matter
Which of the following is not a binder for coal briquetting ?
Which of the following is not a binder for coal briquetting ?
A. Coal tar
B. Bitumen
C. Molasses
D. None of these
Coking time in beehive coke oven is about ___________________?
Coking time in beehive coke oven is about ___________________?
A. 12 hours
B. 2-3 days
C. One week
D. Two weeks
Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature ?
Which of the following is not increased by using preheated combustion air in place of ordinary air at room temperature ?
A. Calorific value of the fuel
B. Flame temperature achieved
C. Speed of combustion of fuel
D. Heat transfer rate to the stock in the furnace
The heat of combustion of a fuel___________________?
The heat of combustion of a fuel___________________?
A. Is equal to the heat of formation
B. Is always negative
C. Can’t be known without calculating it
D. Is always positive