Go To Top Reset
<<= Back
Next =>>
You Are On Multi Choice Question Bank SET 408
20401. Example of an indirectly heated furnace is
(A): both (a) and (b) (B): hood annealing furnace (C): muffle furnace (D): neither (a) nor (b)
20402. Which furnace employs preheating, heating and soaking zones ?
(A): Cupola (B): Open hearth furnace (C): Reheating furnace (D): Soaking pit
20403. Calcination of limestone to produce lime is done in a __________ kiln.
(A): both (b) and (c) (B): rotary (C): tunnel (D): vertical shaft
20404. Thickness of stock does not affect the fuel economy of furnaces, if the material to be heated is of
(A): both (a) and (b) (B): high thermal conductivity (C): low emissivity (D): neither (a) nor (b)
20405. Ceramic recuperators compared to metallic recuperators for the same duty
(A): are less costly. (B): are lighter. (C): have higher pressure differential between flue gas & air side. (D): occupy more space.
20406. In order to maintain a reducing atmosphere in a furnace, it should have
(A): CO in flue gas (B): high excess air (C): no O2 in flue gas (D): none of these
20407. Which is the most thermally efficient furnace ?
(A): Boiler furnace (B): Reheating furnace (C): Reverberatory furnace (D): Rotary kilns
20408. The heat recoverable from flue gases of furnaces depends on the
(A): all (a), (b) and (c). (B): flue gas temperature drop through the furnace. (C): quantity of flue gases. (D): thermal efficiency of furnace.
20409. Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above __________ °C.
(A): 1000 (B): 250 (C): 650 (D): 850
20410. Which is a continuous furnace ?
(A): Annealing furnace (B): Coke ovens (C): Glass tank furnace (D): None of these
20411. Which of the following is the most suitable for preheating combustion air above 650°C ?
(A): Ceramic recuperator (B): Metallic recuperator (C): None of these (D): Regenerator
20412. Soaking pits are meant for heating steel
(A): coils (B): ingots (C): sheets (D): slabs
20413. The purpose of controlling the furnace atmosphere is to prevent surface attack by
(A): decarburising (B): either of the above (C): oxidation/scaling (D): sulphur penetration
20414. Thermal efficiency of a limestone calcination rotary kiln may be around __________ percent.
(A): 20 (B): 40 (C): 65 (D): 80
20415. In producer gas making furnace, steam is added along with air to mainly control the
(A): C. V. of producer gas. (B): fusion of coal ash & clinker formation. (C): tar content in producer gas. (D): temperature of producer gas.
20416. Fuel used in B.F. stove is
(A): blast furnace gas/mixed gas (B): coke oven gas (C): furnace oil (D): pulverised coal
20417. Tunnel kilns are usually used for
(A): drying/tempering of refractories. (B): melting of glass. (C): reheating of slabs. (D): roasting of pyrites.
20418. The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about __________ percent.
(A): 15 (B): 40 (C): 70 (D): 85
20419. Higher furnace temperature can not be achieved by use of a lean fuel gas in the furnace by
(A): increasing the draft in the furnace. (B): oxygen enrichment of combustion air. (C): preheating the combustion air. (D): preheating the fuel gas.
20420. Temperature of a furnace fired with low calorific value fuel gas (i.e. lean gas) can be increased by
(A): all (a), (b) & (c). (B): oxygen enrichment of combustion air. (C): preheating the combustion air. (D): preheating the fuel gas.
20421. Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of
(A): beryllium (B): graphite powder (C): thoria (D): zircon powder
20422. In reverberatory furnace, charge is heated mainly by
(A): conduction. (B): natural convection. (C): none of these. (D): radiation of heat from the roof of the combustion chamber.
20423. An example of a periodic furnace is the
(A): blast furnace (B): blast furnace stoves (C): coke oven heating chamber (D): rotary kilns
20424. Ostwald charts are meant for
(A): calculation of flue gas temperature. (B): computation of flue gas analysis. (C): computing the excess/deficiency of combustion air. (D): none of these.
20425. Maximum heat transfer in high temperature furnaces is by
(A): conduction (B): convection (C): either (a), (b) or (c); depends on the type of furnace (D): radiation
20426. Which of the following is a natural draft furnace ?
(A): Blast furnace stoves (B): None of these (C): Power plant boilers (D): Sintering furnace
20427. To reduce the stack loss, heat recovery from flue gas can be done by
(A): all (a), (b) and (c). (B): preheating of cold stock. (C): preheating of combustion air. (D): steam generation in waste heat boilers.
20428. Large tonnage of refractory bricks are dried in a
(A): muffle furnace (B): rotary hearth furnace (C): shaft furnace (D): tunnel kiln
20429. Pulverised fuel fired furnaces employ __________ fuel firing.
(A): all (a), (b) and (c) (B): horizontal (C): tangential (D): vertical
20430. Which of the following is not a directly fired furnace ?
(A): By-product coke oven (B): Calcination kiln (C): Open hearth furnace (D): Sintering furnace
20431. The reason for excessive clinker formation in gas producers is the
(A): all (a), (b) and (c). (B): development of hot spots in the fuel bed and an abnormally high rate of gasification. (C): use of coal/coke containing a high % of fines and ash. (D): use of fuel having too low an ash fusion temperature.
20432. Which of the following is not an additive for flue gases from furnace to reduce its dew-point?
(A): Alkaline powders (B): Ammonia (C): Fine dolomite (D): None of these
20433. Acid dew point temperature (ADT) of a flue gas produced by the combustion of a fuel containing 1% sulphur may be about __________ °C.
(A): 130 (B): 180 (C): 250 (D): 80
20434. Low stack loss indicates the
(A): efficient use of fuel. (B): inefficient use of fuel. (C): oxygen enrichment of combustion air. (D): use of sub-stoichiometric air for combustion.
20435. Thermal efficiency of blast furnace stoves used for heating blast (air) may be about __________ percent.
(A): 20 (B): 40 (C): 60 (D): 80
20436. Heat transfer rate to the stock/charge in the furnace does not depend upon the
(A): emissivity of the refactory walls. (B): size of the furance. (C): thickness of the stock. (D): use of waste heat recovery equipments.
20437. Which edition of Colon Classification is considered as a freely faceted classification scheme?
(A): First edition (B): Fourth edition (C): Seventh edition (D): Sixth edition
20438. Power required in case of forced draught as compared to induced draught (for the same draught produced) is
(A): either more or less; depends on the flue gas density (B): less (C): more (D): same
20439. Means for giving direction to the circulation of gases in furnaces are
(A): all (a), (b) and (c). (B): arrangement of heating stock in the furnaces. (C): fans. (D): location of outlet ports and heating & combustion devices.
20440. The amount of combustible escaping uncon-sumed from the furnace, depends upon the
(A): air preheat and the flow of gases in the furnace (mixing by induction, by acceleration or by change of direction). (B): air supplied and furnace temperature. (C): all (a), (b) and (c). (D): burner design (thoroughness of mixing versus stratification).
20441. __________ is an indirectly heated furnace.
(A): Muffle furnace (B): Open hearth furnace (C): Reheating furnace (D): Soaking pit
20442. The thermal efficiency of an air/fuel gas preheating recuperator may be as high as __________ percent.
(A): 50 (B): 65 (C): 85 (D): 99
20443. In a muffle furnace, the muffle
(A): all (a), (b) and (c). (B): assists in temperature equalisation in the charge. (C): permits the use of controlled atmosphere for the protection of stock. (D): retards the heat transfer.
20444. Which is not a hearth furnace ?
(A): Cupola (B): Glass tank furnace (C): Open hearth furnace (D): Reheating furnace
20445. An example of shaft furnace is the
(A): blast furnace (B): glass melting tank (C): L.D. converter (D): soaking pit
20446. Which is a regenerative furnace ?
(A): Both (a) and (b). (B): Coke oven heating chamber. (C): Neither (a) nor (b). (D): Open hearth furnace.
20447. Which of the following accentuates clinker-ing troubles on furnace grate burning coal?
(A): All (a), (b) and (c). (B): Low forced draft & fuel bed temperature. (C): Low reactivity of carbonised residue containing high proportion of iron & sulphur. (D): Thick firebed and preheated primary air.
20448. The electric furnace in which heat is produced by a combination of induced current and skin effect is called __________ furnace.
(A): arc (B): high frequency induction (C): low frequency induction (D): resistance
20449. Ingress of cold air in the furnaces through cracks, charging doors, openings etc.
(A): all (a), (b) and (c) (B): increases the load on the induced draft fan. (C): reduces the flue gas temperature and makes the furnace atmosphere oxidising. (D): reduces the furnace draught.
20450. Use of pulverised coal in boilers provides
(A): better combustion (B): higher calorific value (C): less erosion on furnace wall. (D): smokeless burning
<<= Back
Next =>>
Terms And Service:We do not guarantee the accuracy of available data ..We Provide Information On Public Data.. Please consult an expert before using this data for commercial or personal use | Powered By:Omega Web SolutionsPrivacy | Terms And Conditions
Question ANSWER With Solution