Super Heater is a heat exchanger which convers saturated steam into super heated steam. Its constructed in two halves – radiation and convective zones connected to each other by an attemperator. The convective zone of the super heater is shielded from radiation by nose wall, which also guides the flue gas co cover the entire convective super heater area
Economizers are made of bare tubes aids in heat recovery and improving efficiency of the boiler. It uses the heat of the flue gases coming out from the boiler to pre heat the water that goes to the boiler shell. In smaller boilers its not pressurised and in high capacity boilers it is pressurised.
Air Pre Heater is also a heat recovery equipment situated last in the flue gas path. It is a cross flow gas to gas heat exchanger which provides hot air for combustion.
In Bed Coils is a part of FBC boiler where the heat exchanger is immersed in a bubbling send bed, to help take away the heat from the bed . This helps in maintaining combustor temp below the ash melting point using minimal excess air which also results in higher efficiency. Since send is continuously rubbing against the inbed tubes special studding is provided on in bed coils.
Deaerater is a device that is widely used for removal of oxygen and other dissolved gases from the feed water. The presence of dissolved oxygen causes rapid localized corrosion in boiler tubes
Feed water is sprayed in thin films into a steam atmosphere allowing it to quickly heated to saturation . Spraying feed water in thin films increases the surface area of liquid in contact with the steam , which results in more rapid oxygen removal and lower gas concentrations. This process reduces the solubility of all dissolved gases and removes them from the feed water . The liberated gases are then vented out from deaerator