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
Related Mcqs:
- Power required in case of forced draught as compared to induced draught (for the same draught produced) is___________________?
A. Same
B. Less
C. More
D. Either more or less; depends on the flue gas density - Which one is not an induced draught furnace ?
A. Blast furnace stove
B. Sintering furnace
C. High pressure boiler
D. None of these - 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 ?
A. 5
B. 60
C. 20
D. 40 - The electric furnace in which heat is produced by a combination of induced current and skin effect is called _____________ furnace?
A. Arc
B. Resistance
C. Low frequency induction
D. High frequency induction - Artificial draught produced by a fan in the furnace can be controlled by the___________________?
A. Speed of the fan
B. Damper
C. Variation in the pitch of fan blades
D. All A., B. and C. - Forced recirculation of furnace gases is practised_______________?
A. To increase heat transfer by convection
B. To ensure uniform temperature
C. In furnaces, operating below 750°C
D. All A., B. and C. - An improved and fuel efficient version of the pusher type reheating furnace is the ______________ furnace?
A. Walking beam
B. Shaft
C. Tunnel
D. Rotary hearth - While the fuel fired furnace can be used upto a maximum temperature of about 1700°C, the electric furnace can be used upto a temperature of about _____________ °C?
A. 2000
B. 3000
C. 4500
D. 6000 - Which furnace employs an I.D. fan for the removal of flue gases from the furnace ?
A. Coke oven
B. Blast furnace stoves
C. Beehive coke oven
D. High pressure boiler - 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
