A. Burn CO to CO2
B. Dry and transport the coal
C. Have proper combustion by supplying it around the burner
D. Preheat the tertiary air used for complete combustion of CO to CO2
Related Mcqs:
- In case of pulverised coal fired steam boiler, the secondary air serves the main purpose of__________________?
A. Transportation of coal
B. Drying of coal
C. Combustion of coal by supplying it around the burner
D. Preheating the primary air - Temperature of preheated air used for the transportation of pulverised coal through pipes to the burner of a boiler furnace is restricted to a maximum limit of about 300° C to avoid the___________________?
A. Requirement of large volume combustion chamber
B. Risk of explosion
C. Chances of clinker formation
D. Incomplete combustion of coal - Function of secondary air in pulverised coal firing is to_________________?
A. Transport the coal to the burner
B. Dry the coal
C. Ensure efficient burning of coal around the burner
D. Reduce primary air requirement - Which of the following will be unsuitable for dust cleaning from flue gas at 400°C from a pulverised coal fired boiler ?
A. Multicyclones
B. Bag filter
C. Wet scrubber
D. Hydrocyclones - Bunsen burner is an example of a/an _____________ burner?
A. Inside mixing/premix type
B. Outside mixing/diffusion flame/nozzle mix type
C. Rotary cup
D. Submerged combustion - ombustion of pulverised coal compared to the lumpy coal __________________?
CA. Provides better control of furnace temperature
B. Facilitates combustion with lower excess air
C. Provides higher thermal efficiency & flame temperature
D. All A., B. & C. - Combustion of pulverised coal as compared to that of lump coal ________________?
A. Develops a non-luminous flame
B. Develops a low temperature flame
C. Can be done with less excess air
D. Provides a lower rate of heat release - Ratio of primary air to secondary air increases with increase in the rank of coal, because the__________________?
A. High rank coals have higher amount of volatile matter
B. Ratio of fixed carbon to volatile matter increases
C. Oxygen content progressively decreases
D. Calorific value of the coal increases - Bulk density of pulverised coal may be about ______________ kg/m3?
A. 100
B. 500
C. 1000
D. 1500 - Pulverised coal used in boiler firing need not have____________________?
A. Less moisture content
B. High fusion point of its ash
C. High bulk density
D. Lower ash content
