Fluidized bed combustion technology used to burn solid fuels

Commercial FBC units operate at competitive efficiencies, cost less than today's conventional boiler units, and have NO2 and SO2 emissions below levels mandated by Federal standards. However, they have some disadvantages such as erosion on the tubes inside the boiler, uneven temperature distribution caused by clogs on the air inlet of the bed, long starting times reaching up to 48 hours in some cases. ZBG provide global customers with high efficient and commercial boiler. coal fired CFB boiler, packaged coal fired boiler, biomass fired boiler,etc.

PROCESS AND TECHNOLOGY STATUS

Combustion boilers are widely used to generate steam for industrial, applications and power generation.  While all kinds of energy sources - fossil fuels, biomass, nuclear and solar energy, Electricity can be used to generate heat and steam, the scope of this brief is limited to combustion boilers using fossil fuels and biomass.

Fluidized bed combustion (FBC) is a combustion technology used to burn solid fuels.

In its most basic form, fuel particles are suspended in a hot, bubbling fluidity bed of ash and other particulate materials (sand, limestone etc.) through which jets of air are blown to provide the oxygen required for combustion or gasification. The resultant fast and intimate mixing of gas and solids promotes rapid heat transfer and chemical reactions within the bed. FBC plants are capable of burning a variety of low-grade solid fuels, including most types of coal and woody biomass, at high efficiency and without the necessity for expensive fuel preparation (e.g., pulverising). In addition, for any given thermal duty, FBCs are smaller than the equivalent conventional furnace, so may offer significant advantages over the latter in terms of cost and flexibility.

FBC Technology Feature

1.FBC has a lower combustion temperature of 750 °C whereas an ordinary boiler operates at 850 °C.
2.FBC has low sintering process (melting of Ash).
3.Lower production of NOx due to lower temperature.
4.Lower production of SOx due to capture by limestone.
5.Higher combustion efficiency due to 10 times more heat transfer than other combustion processes because of burning particle.
6.Less area is required for FBC due to high coefficient of convective heat transfer.
7.Iso-thermal bed combustion as temperature in free belt and active belt remain constant.