Incomplete combustion of fuel in the furnace is judged by high __________ of the flue gases.
A. CO content
B. Dew point
C. CO2 content
D. O2 content
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High sulphur content in a fuel __________ of the flue gases.
A. Decreases the dew point
B. Increases the dew point
C. Reduces the combustion efficiency by limiting the permissible temperature reduction
D. Both B & C
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Fusion point of coal ash generally varies from 1000 to 1700°C. Ash having fusion point less than __________ °C is liable to form clinker.
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Coal tar fuel - 200 (CTF 200) is a mixture of
A. Pitch and creosote oil
B. Light oil and pitch
C. Anthracene and crecosote oil
D. Solar oil and pitch
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Kopper-Totzek coal gasifier (installed in a coal based nitrogeneous fertiliser plant) employs a/an __________ bed gasifier.
A. Entrained
B. Moving
C. Fixed
D. Fluidised
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Which of the following combustibles is absent in blast furnace gas?
A. H2
B. CH4
C. CO
D. None of these
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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)
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A sample of natural gas containing 80% methane (CH4 ) and rest nitrogen (N2 ) is burnt with 20% excess air. With 80% of the combustibles producing CO2 and the reminder going to CO, the Orsat analysis in volume percent is
A. CO2 : 6.26, CO : 1.56, O2 : 3.91, H2 O : 15.66, N2 : 72.60
B. CO2 : 7.42, CO : 1.86, O2 : 4.64, N2 : 86.02
C. CO2 : 6.39, CO : 1.60, O2 : 3.99, H2 O : 25.96, N2 : 72.06
D. CO2 : 7.60, CO : 1.90, O2 : 4.75, N2 : 85.74
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Calorific value of gobar gas (containing CH4 = 60%, H2 = 10%, CO2 = 30%) may be about __________ Kcal/Nm3 .
A. 1800
B. 3200
C. 5400
D. 10200
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Calorific value of coal middling generated in coal washeries during washing of coal may be around __________ Kcal/kg.
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Calorific value of dry wood may be around __________ Kcal/kg.
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Calorific value of bituminous coal may be around __________ Kcal/kg.
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Calorific value of a typical dry anthracite coal may be around __________ Kcal/kg.
A. 1000
B. 4000
C. 8000
D. 15000
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Ash content in the coke produced from a coking coal having 20% ash may be around __________ percent.
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Pick out the wrong statement.
A. Pulverised fuel can be completely burnt with less percentage of excess air compared to lump coal
B. Low grade coal can be used, but generally high volatile matter coals are more suitable for making pulverised fuel
C. Regulation of furnace temperature and atmosphere (oxidising or reducing) is easily possible with pulverised fuel firing
D. None of these
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Volatile matter content of metallurgical coke may be around __________ percent.
A. 1-2
B. 10-15
C. 22-26
D. 30-33
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Quantity of coke produced from metallurgical coal may be around __________ percent.
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Abrasion index of blast furnace coke should be around __________ percent.
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Which of the following is not a binder for coal briquetting?
A. Coal tar
B. Bitumen
C. Molasses
D. None of these
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Natural draught produced by a chimney depends upon the
A. Density of the chimney gases
B. Height of the chimney
C. Both A & B
D. Neither A nor B
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