A. Increased fuel consumption
B. Incomplete combustion
C. Smoky flame
D. None of these
Related Mcqs:
- 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 - The main drawback of supplying more excess air in the combustion of fuel is the_________________?
A. Excessive power requirement of air blower
B. Enhanced sensible heat loss in the flue gas
C. Intermittent and uncontrolled combustion of the fuel
D. High exit flue gas temperature from the furnace - Supply of excess air for complete combustion of fuel is necessitated to facilitate___________________?
A. Its thorough mixing with air
B. Attainment of chemical equilibrium
C. Attainment of high temperature
D. None of these - The optimum percentage of excess air for combustion depends upon the _______________ of the fuel?
A. Type (solid, liquid or gaseous)
B. Calorific value
C. Sulphur content
D. Ignition temperature - 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 - Too much of excess air in combustion results in high___________________?
A. Fuel consumption for the same heat load
B. Stack gas temperature
C. Percentage of oxygen in flue gases
D. All A., B. and C. - 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 - 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) - 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 - Combustion reaction of fuels is a/an ______________ reaction?
A. Auto catalytic
B. Exothermic
C. Endothermic
D. None of these
