A. Coke breeze containing 25% ash and 2% volatile matter
B. Anthracite containing 10% volatile matter and 8% ash
C. Bituminous coal containing 20% ash and 25% volatile matter
D. Semi-bituminous coal containing 25% ash and 20% volatile matter
Related Mcqs:
- Which of the following fuel gases will require maximum amount of air for combustion of 1 Nm3 gas ?
A. Blast furnace gas
B. Natural gas
C. Producer gas
D. Water gas - Which of the following would require maximum amount of % excess air for complete combustion ?
A. Coke oven gas
B. Furnace oil
C. Pulverised coal
D. Lump coal (fixed on chain grate) - Use of excess of combustion air in the combustion of fuels results in__________________?
A. Heat losses
B. Long flame
C. Condensation of water vapour from the fuel gas
D. None of these - Deficiency of combustion air during combustion of a gaseous fuel_____________________?
A. Lengthens the flame
B. Causes heat loss of fuel by its partial combustion
C. Both A. & B.
D. Shortens the flame - The function of secondary combustion air is to ______________________?
A. Pneumatically convey the pulverised coal
B. Completely burn the volatile matter
C. Burn the lumpy coal
D. None of these - 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 - As the C/H ratio of the fuel increases, the amount of CO2 formed on combustion _______________ for the same percentage of excess air?
A. Decreases
B. Increases
C. Remain same
D. May increase or decrease depending on the type of fuel - Ratio of primary air to secondary air increases with increase in the rank of coal, because the__________________?
A. High rank coals have higher amount of volatile matter
B. Ratio of fixed carbon to volatile matter increases
C. Oxygen content progressively decreases
D. Calorific value of the coal increases - Furnace oil consumption in a furnace for a given duty employing preheated combination air (at 300°) may be reduced by about ______________ percent as compared to the use of atmospheric combustion air?
A. 5
B. 10
C. 20
D. 35 - For the case of a fuel gas undergoing combustion with air, if the air/fuel ratio is increased, the adiabatic flame temperature will_____________________?
A. Increase
B. Decrease
C. Increase or decrease depending on the fuel type
D. Not change
