Fuel and Ash Circuit and Air and Gas Circuit in Thermal Power Plant
Fuel and Ash Circuit
- Fuel i.e. coal, from the storage is fed to the boiler through feeding device, which consists of conveyor belt, crushing mill etc. and is called as coal handling plant. Ash produced as a result of combustion of coal collects at the back of the boiler and is removed to ash storage through ash handling equipment.
Air and Gas Circuit
- Atmospheric air is supplied for combustion of coal in the boiler, through the action of Forced Drought (F.D.) fan or Induced Draught (I.D.) fan. The air, before being supplied to the boiler, passes through air preheater where it is heated by the heat of flue gases, which then passes to the chimney.
- The flue gases first pass around the boiler tubes and superheater tubes in the furnace, thereafter they pass through dust collector or dust precipitator, and then pass through economizer.
- At the end they are exhausted to the atmosphere through air preheater.