A. Burns completely
B. Gives smokeless burning
C. Shows little or no fusing action
D. None of these
Related Mcqs:
- Calorific value of coal middling generated in coal washeries during washing of coal may be around _____________ Kcal/kg?
A. 1000
B. 4000
C. 6000
D. 8000 - 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. - Coal is pulverised before burning in large capacity boiler furnaces mainly to____________________
A. Ensure its complete combustion
B. Facilitate easy ash removal
C. Enhance its calorific value
D. Provide trouble free operation - A travelling grate stoker is meant for the efficient burning of ______________ coal?
A. Caking
B. Pulverised
C. Non-caking
D. High ash - Which of the following accentuates clinkering trouble on furnace grate burning coal ?
A. Low reactivity of carbonised residue containing high proportions of iron & sulphur
B. Low forced draught and fuel bed temperature
C. Thick fire bed and preheated primary air
D. All A., B. and C. - Efficient burning of anthracite coal requires______________________?
A. Low preheat of air
B. Fine grinding
C. High excess air
D. All A., B. and C - A gaseous fuel in order to develop luminosity on burning, must contain __________________?
A. Carbon monoxide
B. Hydrocarbons
C. Hydrogen
D. Oxygen - “Overfire burning” in a furnace is a phenomenon characterised by the __________________?
A. Supply of excess fuel
B. Supply of excess air
C. Burning of carbon monoxide and other incombustibles in upper zone of furnace by supplying
more air
D. None of these - Fuel gases containing hydrocarbons (e.g. coke oven gas) are not preheated before burning, mainly because __________________?
A. The hydrocarbons crack thereby choking and fouling the heat transfer surface by carbon soot
B. It reduces its calorific value tremendously
C. It reduces its flame temperature tremendously
D. There are chances of explosion during preheating - The liquid used for the washing of coal in an industrial coal washery is a mixture of water and ____________________?
A. Carbon tetrachloride
B. Sand (40%)
C. Mineral oil of high viscosity & specific gravity (1.6)
D. None of these
