A. The hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
B. It reduces its calorific value tremendously
C. It reduces its flame temperature tremendously
D. There are chances of explosion during preheating
Related Mcqs:
- Coke oven gas is a better fuel than blast furnace gas, because of its higher________________?
A. Calorific value, cleanliness and relatively low distribution cost (due to its low specific gravity)
B. Adiabatic flame temperature
C. Heat release rate (thus requiring smaller combustion chamber)
D. All A., B. and C. - A carbonaceous fuel (containing no H2 or hydrocarbons) is burnt and the resulting flue gas contains 21% CO2. It means that___________________?
A. 21% excess air has been used for combustion
B. 21% excess oxygen has been used for combustion
C. Complete combustion of fuel has taken place
D. No excess air has been used for combustion - A liquid/gaseous fuel containing hydrocarbons and high amount of sulphur is burnt with 40% excess air. The flue gas still contains large amount of carbon monoxide. This may be due to the_________________?
A. Presence of large quantity of hydrogen in the fuel
B. Low calorific value of the fuel
C. High sulphur content in the fuel
D. Lack of thorough mixing of fuel with air - Coke oven gas constitutes mainly of ____________________?
A. H2 & CO
B. H2 & CH4
C. CH4 & CO
D. H2 & CO2 - Temperature of coke oven gas just before entering into saturator (for recovery of NH3) is about ______________ °C?
A. 30
B. 65
C. 120
D. 180 - Coke oven gas burns with a yellowish flame, because of the presence of __________________?
A. CO2
B. CH4
C. H2
D. NH3 - Width of the coke oven towards coke side is slightly more than that on pusher side to____________________?
A. Facilitate easy discharging of coke as it swells during carbonisation
B. Facilitate uniform heating of the oven
C. Increase the output of the coke
D. None of these - Blast furnace gas compared to coke oven gas has_________________?
A. Lower ignition temperature
B. Narrower limit of inflammability
C. Higher calorific value
D. Lower theoretical flame temperature - Coke oven gas compared to blast furnace gas is________________?
A. More explosive and inflammable
B. Less poisonous
C. Lighter
D. All A., B. and C. - Height of coke oven is limited (say maximum upto 7 metres) mainly by the_____________________?
A. Problem of uniform heating along its height
B. Structural strength of silica bricks
C. Problem in door cleaning
D. Buckling of ram of pusher car at the time of coke pushing
