A. 50
B. 65
C. 85
D. 99
Related Mcqs:
- Thermal efficiency of blast furnace stoves used for heating blast (air) may be about _____________ percent?
A. 20
B. 40
C. 60
D. 80 - Thermal efficiency of an open hearth furnace may be about _____________ percent?
A. 5
B. 20
C. 50
D. 80 - Maximum thermal efficiency of boiler may be about _____________ percent?
A. 10
B. 25
C. 65
D. 90 - Thermal efficiency of a limestone calcination rotary kiln may be around ______________ percent?
A. 20
B. 40
C. 65
D. 80 - The thermal efficiency of a steel slab reheating furnace (walking beam type) may be about ____________ percent?
A. 15
B. 40
C. 70
D. 85 - 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 - Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above _____________ °C?
A. 250
B. 650
C. 850
D. 1000 - Oxygen percentage in the flue gas coming out of a gaseous fuel fired furnace should be ideally about _____________ percent?
A. < 2
B. < 5
C. < 8
D. < 10 - Which of the following is the most suitable for preheating combustion air above 650°C ?
A. Regenerator
B. Metallic recuperator
C. Ceramic recuperator
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
