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
Related Mcqs:
- The advantages of firing pulverised coal in the furnace lies in the fact that, it_____________________?
A. Permits the use of high ash content coal
B. Permits the use of low fusion point ash coal
C. Accelerates the burning rate and economises on fuel consumption
D. All A., B. and C. - 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 - Pulverised fuel fired furnaces employ ______________ fuel firing?
A. Horizontal
B. Vertical
C. Tangential
D. All A., B. and C. - Use of pulverised coal in boilers provides____________________?
A. Higher calorific value
B. Better combustion
C. Smokeless burning
D. Less erosion on furnace wall - Amount of coal lost in ash particle, which is carried through the boiler system, depends upon the__________________?
A. Physical nature, ash content and fineness of the coal
B. Amount of excess air supplied and load on the boiler
C. Type of burner and combustion chamber
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. - Maximum thermal efficiency of boiler may be about _____________ percent?
A. 10
B. 25
C. 65
D. 90 - The function of an economiser in a boiler is to preheat the _____________________?
A. Feedwater
B. Combustion air
C. Pulverised coal
D. Furnace oil - Which of the following accentuates clinkering troubles on furnace grate burning coal ?
A. Low reactivity of carbonised residue containing high proportion of iron & sulphur
B. Low forced draft & fuel bed temperature
C. Thick firebed and preheated primary air
D. All A., B. and C. - 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
