A. 10
B. 25
C. 65
D. 90
Related Mcqs:
- The thermal efficiency of an air/fuel gas preheating recuperator may be as high as _____________ percent?
A. 50
B. 65
C. 85
D. 99 - Thermal efficiency of an open hearth furnace may be about _____________ percent?
A. 5
B. 20
C. 50
D. 80 - 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 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 - Which of the following furnaces will have maximum thermal efficiency ?
A. Soaking pits
B. Walking beam reheating furnace
C. Boiler furnace
D. Rotary kilns - Thermal efficiency of furnaces can be improved by____________________?
A. Waste heat recovery from flue gas
B. Minimising heat losses from furnace walls
C. Maintaining proper draught
D. All A., B. and C. - Design of waste heat boiler for recovery of waste heat from furnace gases depends upon the_________________?
A. Quantity & temperature of waste gas
B. Dust concentration & nature of dust in waste gas
C. Corrosive nature of the waste gas
D. All A., B. and C. - Which of the following is the most important deterrents to an extended use of pulverised coal in boiler firing ?
A. Ash disposal problem
B. Excessive fly ash discharge from the stack
C. Higher power consumption in its transportation
D. Erosion of induced draft fan blades
