A. Are lighter
B. Occupy more space
C. Are less costly
D. Have higher pressure differential between flue gas & air side
Related Mcqs:
- Regenerators as compared to recuperators for the same duty_________________?
A. Store smaller quantity of waste heat
B. Are lighter & compact
C. Involve higher initial cost
D. All A., B. & C. - Ceramic recuperators (made of SiC) is economical, only when used for preheating combustion air above _____________ °C?
A. 250
B. 650
C. 850
D. 1000 - Metallic recuperators are not used for waste heat recovery, if the hot flue gas temperature is above _____________ °C, because corrosion prevails at higher temperatures?
A. 350
B. 750
C. 1050
D. 1250 - Regenerators compared to the recuperators for the same duty__________________?
A. Occupy more space
B. Are less costly
C. Are of smaller size
D. All A., B. and C. - 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 - 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 - 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 - In a furnace employing forced draught as compared to induced draught______________________?
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 - The heating capacity of muffle furnace depends on the_________________?
A. Surface area & emissivity of the stock
B. Properties of the muffle wall (temperature, area, and emissivity)
C. Both A. & B.
D. Neither A. nor B. - 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.
