If oxygen content in the flue gas rises too high, fuel is being wasted by
A. Incomplete combustion
B. Dry gas/stack gas loss
C. Moisture loss
D. None of these
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Coking time in beehive coke oven is about
A. 12 hours
B. 2-3 days
C. One week
D. Two weeks
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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 of the above
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Catalyst used in Fischer-Tropsch process is
A. Nickel
B. Zinc oxide
C. Alumina
D. Thorium oxide
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The cuprous chloride used in orsat apparatus can absorb
A. Only CO
B. Both CO and CO2
C. Both CO and O2
D. All of the above
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Pick out the wrong statement.
A. Cokes of high reactivity are obtained from weakly coking coals
B. Cokes of high reactivity are obtained from strongly coking coals
C. Reactivity of coke is inversely proportional to its absolute density
D. Abrasion index of the coke is a measure of its hardness
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The pyragallol solution used in orsat apparatus can absorb
A. Only O2
B. Both O2 and CO2
C. Both O2 and CO
D. All of the above
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Use of preheated air for combustion of fuel in the furnace, increases the
A. Scale losses of the furnace stock
B. Calorific value of the fuel
C. Flame temperature
D. None of these
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C.V. (kcal/Nm3 ) of gaseous fuels __________ with increase in molecular weight.
A. Decreases
B. Increases
C. Remains constant
D. May increase or decrease, depends on combustibles
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'Wobbe index' is a characteristic of
A. Solid fuels
B. Gaseous fuels
C. Liquid fuels
D. Fat coals
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Pitch creosote mixture (PCM) as compared to furnace oil is a better fuel, because its
A. Emissivity factor is higher
B. Sulphur content is lower
C. Flue gas has lower dew point thereby facilitating more waste heat recovery
D. All of the above
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The calorific value of natural gas is about __________ kcal/Nm3 .
A. 10,000
B. 2,500
C. 25,000
D. 35,000
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Calorific value of wood gas is about __________ kcal/Nm3 .
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Calorific value of coke even gas produced by low temperature carbonisation of coal is about __________ kcal/Nm3 .
A. 4000
B. 2500
C. 6500
D. 10000
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The calorific value of 'LPG' (50% propane + 50% butane) is about __________ kcal/Nm3 .
A. 5,000
B. 25,000
C. 10,000
D. 15,000
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The calorific value of producer gas is around __________ kcal/Nm3 .
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Yield of pitch from distillation of high temperature tar is around __________ percent.
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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
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In high temperature carbonisation of coal compared to low temperature carbonisation
A. Yield of ammonia is less
B. Aromatic content of tar is low
C. H2 content in the coke oven gas is more
D. Calorific value of the coke oven gas is lower
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Initial pressure of oxygen introduced into the 'bomb' of the bomb calorimeter for determination of calorific value of coal/fuel oil may be around __________ atm.
A. 3-5
B. 25-30
C. 60-65
D. 95-100
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