A. Preheating of cold stock
B. Preheating of combustion air
C. Steam generation in waste heat boilers
D. All A., B. and C.
Related Mcqs:
- Out of the following fuels used in a furnace exhausting flue gas at a temperature of 600°C, the percentage stack loss will be maximum in case of complete combustion of_________________?
A. Furnace oil with air
B. Furnace oil with oxygen
C. Blast furnace gas with air
D. Blast furnace gas with oxygen - 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 - Which of the following is not a continuous waste heat recovery equipment from the flue gases going out of furnace ?
A. Economiser
B. Regenerator
C. Ceramic recuperator
D. Waste heat boiler - 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. - In a furnace, the heat taken by the charge/stock and the heat lost to the furnace structure & flue gases depends on the__________________?
A. Rate of firing and emissivity of flame
B. Thermal conductivity of the charge & structural materials of furnace
C. Nature of process; whether batch, continuous or intermittent
D. All A., B. and C. - Which of the following is not an additive for flue gases from furnace to reduce its dewpoint ?
A. Ammonia
B. Fine dolomite
C. Alkaline powders
D. None of these - Regenerators are used for waste heat recovery in____________________?
A. By-product coke ovens
B. Beehive coke oven
C. Blast furnace stoves
D. Soaking pits - Waste heat from the outgoing flue gases in a thermal power plant is recovered by a/an_________________?
A. Economiser
B. Steam superheater
C. Air preheater
D. All A., B. and C. - 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 - 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
