Which of the following will generate maximum volume of product of complete combustion (Nm3 /Nm3 of fuel)?
A. Carburetted water gas
B. Blast furnace gas
C. Natural gas
D. Producers gas
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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
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High excess air in combustion of fuels results in
A. Increased fuel consumption
B. Incomplete combustion
C. Smoky flame
D. None of these
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Combustion of pulverised fuel
A. Requires larger combustion chamber than rich gaseous fuel
B. In a metallurgical furnace does not contaminate the product in the furnace by ash from fuel
C. Suppresses the discharge of fine dust and grit into atmosphere
D. All of the above
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The internal energy of the combustion products is __________ compared to that of reactants.
A. More
B. Less
C. Equal
D. More or less ; (depends on the state of fuel.)
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For every 10% increase in the excess air; the fuel consumption increases by __________ percent.
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Correct viscosity of furnace oil at the burner tip for proper atomisation is about 25 centistokes. To reduce the viscosity of high viscosity furnace oil (250 centistokes) to the correct atomisation viscosity (i.e. 25 cst), it should be preheated to about____°C.
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Fixed carbon in coal is defined as
A. That present in volatile matters
B. The total quantity of carbon present in the coal
C. Hundred minus the percentage of volatile matter, ash and moisture
D. The one which is present in the residue after combustion
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The most matured coal out of the following is
A. Lignite
B. Semi-anthracite
C. Sub-bituminous
D. Bituminous
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Yield of charcoal in high temperature carbonisation of wood is about __________ percent.
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While the first commercial low temperature coal carbonisation plant is located at Neyveli (in Chennai), the second such plant has been built at
A. Dankuni (West Bengal)
B. Dhanbad
C. Singreni (A.P.)
D. Raniganj
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The maximum adiabatic flame temperature is attained, when the fuel is burnt with
A. Theoretically required amount of air
B. More than theoretically required amount of air
C. Less than theoretically required amount of air
D. Theoretically required amount of oxygen
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To avoid fire by spontaneous combustion of coal due to its low temperature oxidation, it should be stored in
A. Shallow and small piles
B. Fine sizes without the presence of any lump
C. Closed space without any ventilation facility
D. Large heaps with small surface to volume ratio
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Which of the following is not applicable to fluidised bed combustion of coal?
A. It can not burn low grade coal
B. It achieves higher fuel combustion efficiency
C. Less heat transfer surface area is required in boilers
D. None of these
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Size of blast furnace grade coke is __________ mm.
A. 25-80
B. 0-15
C. 15-25
D. >100
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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
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The ratio of % total carbon obtained in the ultimate analysis of coke and % fixed carbon obtained in the proximate analysis is always
A. 1
B. < 1
C. > 1
D. Unpredictable
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Compound coke ovens are those which can be heated by
A. Both steam and electrical power
B. Lean gas (e.g., B.F. gas)
C. Rich gas (e.g., coke oven gas)
D. Both B and C
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Bomb calorimeter is used to determine the (where, GCV - Gross Calorific Value. NCV - Net Calorific Value.)
A. GCV at constant pressure
B. GCV at constant volume
C. NCV at constant pressure
D. NCV at constant volume
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Which of the following is a measure of the agglutinating (i.e., binding) property of coal?
A. Thickness of plastic layer
B. Caking index
C. Swelling index
D. Gray-king index
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