Combustion of furnace oil in a furnace (soaking pit) with preheated combustion air at 400°C results in saving of about __________ percent furnace oil as compared to its combustion with atmospheric air, if the flue gas outlet temperature from the soaking pit is 1200°C.
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Rotary kilns are used in the
A. Calcination of limestone & dolomite
B. Cement manufacture
C. Both A and B
D. Neither A nor B
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Regenerators are normally provided in the
A. Glass melting furnace
B. Open hearth furnace
C. By product coke ovens
D. All of the above
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In a furnace employing forced draught as compared to induced draught,
A. Air is sucked in, so air leaks are more and hence the furnace efficiency is reduced
B. The fan operates hot and hence blades are liable to corrosion and erosion
C. Positive pressure exists in the furnace
D. None of these
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Coke ovens in steel plant are heated by
A. Electricity
B. Blast furnace gas/mixed gas
C. Coke oven gas
D. Both B and C
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Which of the following is not a recuperative furnace?
A. Soaking pit
B. Reheating furnace
C. Steamboiler
D. Coke oven
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The purpose of controlling the furnace atmosphere is to prevent surface attack by
A. Oxidation/scaling
B. Decarburising
C. Sulphur penetration
D. Either of the above
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Regenerators are used for waste heat recovery in
A. By-product coke ovens
B. Beehive coke oven
C. Blast furnace stoves
D. Soaking pits
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The heat recoverable from flue gases of furnaces depends on the
A. Thermal efficiency of furnace
B. Quantity of flue gases
C. Flue gas temperature drop through the furnace
D. All of the above
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Shaft furnaces are used for
A. Smelting
B. Calcining
C. Roasting
D. All of the above
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Reheating furnace (pusher type) is used for heating
A. Ingots
B. Slabs
C. Steel coils
D. Steel sheets
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Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C.
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In which of the waste heat recovery equipment, the flow of flue gas and air is alternately reversed after a fixed interval of time?
A. Recuperator
B. Regenerator
C. Waste heat boiler
D. None of these
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Turndown ratio of a burner gives an idea of the __________ in the furnace.
A. Range of fuel firing rates
B. Volume of the combustion chamber
C. Maximum heat input rate only
D. Minimum heat input rate only
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Furnace aerodynamics is related to the __________ in the furnace.
A. Movement of gases
B. Measurement of flue gas volume
C. Temperature control
D. Pressure adjustment
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In a furnace operation, which is not preheated?
A. Solid fuels
B. Hydrocarbon containing fuel gases (e.g. coke oven gas, refinery gas etc.)
C. Both A and B
D. Neither A nor B
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Soaking pits are meant for heating steel
A. Ingots
B. Coils
C. Sheets
D. Slabs
Select an option to see the answer and solution.
Turn down ratio of a burner
A. Should be as low as possible i.e., 1 : 2
B. Should be 1:1 for a batch type furnace.
C. Is the ratio of maximum to minimum permissible heat input rates
D. Is normally much more for a continuous furnace as compared to a batch furnace
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Heat transfer takes place through a liquid medium surrounding the submerged material under heating, in case of a/an
A. Blast furnace
B. Steam boiler
C. Salt bath furnace
D. Annealing furnace
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Unit of furnace loading is
A. Ton stock/hr/m2 hearth area
B. Ton stock/hr
C. Ton stock/m2 hearth area
D. Both B and C
Select an option to see the answer and solution.
