to provide proper conditions for continuous complete combustion

mix fuel with air and ignite

separate ash from coal

maintain heat supply to prepare and ignite the incoming fuel

it has heating value

it helps in electrostatic precipitation of ash in flue-gases

it leads to corrosion of air heaters, ducting, etc. if flue gas exit temperature is low

it erodes furnace walls

(1- moisture content)

(1 + moisture content)

1 + moisture content

1 - moisture content

higher effectiveness of boiler

high calorific value coal being burnt

fouling of heat transfer surfaces

raising of steam temperature

smoky chimney exit

excess air in flue gases

measuring carbon mono-oxide in flue gases

measuring temperature of flue gases at exit of furnace