Furnace Technology Mcqs for Chemical - Set 6

1)   Overall thermal efficiency of a lumpy coal fired suitably designed heating furnace, if operated & maintained properly may be about ____________ percent?

a. 10-15
b. 25-30
c. 45-50
d. 65-70
Answer  Explanation 

ANSWER: 25-30

Explanation:
No explanation is available for this question!


2)   Higher furnace temperature cannot be achieved by use of a lean fuel gas in the furnace by_________________?

a. Increasing the draft in the furnace
b. Preheating the fuel gas
c. Oxygen enrichment of combustion air
d. Preheating the combustion air
Answer  Explanation 

ANSWER: Increasing the draft in the furnace

Explanation:
No explanation is available for this question!


3)   Heat transfer rate to the charge/stock in a furnace does not depend upon the________________?

a. Type of fuels viz. solid, liquid or gaseous
b. Flue gas temperature
c. Emissivity of refractory walls
d. Initial temperature of the charged stock
Answer  Explanation 

ANSWER: Type of fuels viz. solid, liquid or gaseous

Explanation:
No explanation is available for this question!


4)   The amount of combustible escaping unconsumed from the furnace, depends upon the________________?

a. Air supplied and furnace temperature
b. Burner design (thoroughness of mixing versus stratification)
c. Air preheat and the flow of gases in the furnace (mixing by induction, by acceleration or by change of direction)
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


5)   Reducing atmosphere is maintained in a__________________?

a. Calcination kiln
b. Blast furnace
c. Soaking pit
d. L.D. converter
Answer  Explanation 

ANSWER: Blast furnace

Explanation:
No explanation is available for this question!


6)   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
Answer  Explanation 

ANSWER: Salt bath furnace

Explanation:
No explanation is available for this question!


7)   Ceramic coating material for furnace refractory, which increases its emissivity and thus the radiation heat transfer rate in the furnace, comprises of_________________?

a. Graphite powder
b. Thoria
c. Zircon powder
d. Beryllium
Answer  Explanation 

ANSWER: Zircon powder

Explanation:
No explanation is available for this question!


8)   Which one is not an induced draught furnace ?

a. Blast furnace stove
b. Sintering furnace
c. High pressure boiler
d. None of these
Answer  Explanation 

ANSWER: Blast furnace stove

Explanation:
No explanation is available for this question!


9)   Furnace pressure is normally controlled by regulating the__________________?

a. Air pressure
b. Fuel gas pressure
c. Speed of I.D. fan
d. Damper
Answer  Explanation 

ANSWER: Damper

Explanation:
No explanation is available for this question!


10)   ______________ is an indirectly heated furnace?

a. Open hearth furnace
b. Muffle furnace
c. Soaking pit
d. Reheating furnace
Answer  Explanation 

ANSWER: Muffle furnace

Explanation:
No explanation is available for this question!


11)   
Fuel economy in furnaces can be achieved by_________________?


a. Using oxygen enriched combustion air
b. Preheating the combustion air
c. Reducing the heat loss through furnace openings & doors
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


12)   Ingress of cold air in the furnaces through cracks, charging doors, openings etc ________________?

a. Reduces the flue gas temperature and makes the furnace atmosphere oxidising
b. Increases the load on the induced draft fan
c. Reduces the furnace draught
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


13)   Which is the most thermally efficient furnace _______________________?

a. Reheating furnace
b. Reverberatory furnace
c. Rotary kilns
d. Boiler furnace
Answer  Explanation 

ANSWER: Boiler furnace

Explanation:
No explanation is available for this question!


14)   The advantages of firing pulverised coal in the furnace lies in the fact that, it_____________________?

a. Permits the use of high ash content coal
b. Permits the use of low fusion point ash coal
c. Accelerates the burning rate and economises on fuel consumption
d. All A., B. and C.
Answer  Explanation 

ANSWER: Accelerates the burning rate and economises on fuel consumption

Explanation:
No explanation is available for this question!


15)   _____________ furnace is not an electric furnace?

a. Arc
b. Induction
c. Pot
d. Resistance
Answer  Explanation 

ANSWER: Pot

Explanation:
No explanation is available for this question!


16)   To reduce the stack loss, heat recovery from flue gas can be done by_____________________?

a. Preheating of cold stock
b. Preheating of combustion air
c. Steam generation in waste heat boilers
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


17)   Size of the combustion chamber of a furnace depends upon the ___________________?

a. Heat release rate of the fuel
b. Preheat temperature of fuel & air
c. Method of mixing the fuel & air
d. All A., B. and C.
Answer  Explanation 

ANSWER: All A., B. and C.

Explanation:
No explanation is available for this question!


18)   An electric furnace producing heat by means of an electric arc struck between each of three electrodes and the charge is called ____________ furnace?

a. Resistance
b. Arc
c. Low frequency induction
d. None of these
Answer  Explanation 

ANSWER: Arc

Explanation:
No explanation is available for this question!


19)   Which of the following is a heat treatment furnace ?

a. Muffle furnace
b. Annealing furnace
c. Reheating furnace
d. Rotary kiln
Answer  Explanation 

ANSWER: Annealing furnace

Explanation:
No explanation is available for this question!


20)   In practical operation of any furnace, zero oxygen percentage or theoretical CO2 percentage in flue gas is rarely achieved, because of__________________?

a. Use of non-preheated combustion air
b. Use of pulverised solid fuels
c. Imperfect mixing of fuel & air and infiltration of air
d. Use of excessive positive draft in the furnace
Answer  Explanation 

ANSWER: Imperfect mixing of fuel & air and infiltration of air

Explanation:
No explanation is available for this question!