Bubbling Fluidized Bed Boiler Or Circulating Fluid Bed Boiler
Bubbling fluidized bed boiler or Circulating fluidized bed boiler?
Boiler engineers can choose between two main types of fluidized-bed boilers—bubbling fluidized bed (BFB) and circulating fluidized bed (CFB). In BFB boilers the velocity of the combustion air is low enough that the fluidized particles remain in the lower furnace; in a CFB unit the velocity is greater and hot particles are circulated through the entire range of the boiler combustion zone. The fuel is in contact with the particles and effective mixing and combustion allows good efficiency and low emissions. Typically 97% to 99% of all burnable carbon in the fuel stream is combusted, even hard-to-burn materials. Boiler thermal efficiencies can be as high as 87% or more. Although both BFB and CFB systems are effective with biofuels, CFB is especially suitable for large boiler load ranges.
ZG boiler engineer said, "Bed combustion temperature control is fundamental to fluid-bed boilers, Bed temperature is controlled to limit emissions and to limit bed material agglomeration."
Agglomeration can be caused by alkaline ash, other metals, and phosphates combining with alumina and silica to form low-melting-point eutectics that coat the bed particles. If alkali concentrations are too high the coatings melt and bond the particles together; these larger agglomerated particles become too heavy and interfere with the fluidization process.
CFB technology provides fuel flexibility in that it can burn wood and high Btu fuels. ZG report that CFBs are common in Europe for renewable energy projects that burn lower moisture fuels, such as clean urban waste wood.
"Making the decision between a BFB or CFB system is not always obvious and should be evaluated on a case-by-case basis," advises by exports from ZG CFB boiler company. "Parasitic power requirements play a very important role in the evaluation process and ultimately system reliability is critical for any given project. That evaluation begins with a thorough
Boiler engineers can choose between two main types of fluidized-bed boilers—bubbling fluidized bed (BFB) and circulating fluidized bed (CFB). In BFB boilers the velocity of the combustion air is low enough that the fluidized particles remain in the lower furnace; in a CFB unit the velocity is greater and hot particles are circulated through the entire range of the boiler combustion zone. The fuel is in contact with the particles and effective mixing and combustion allows good efficiency and low emissions. Typically 97% to 99% of all burnable carbon in the fuel stream is combusted, even hard-to-burn materials. Boiler thermal efficiencies can be as high as 87% or more. Although both BFB and CFB systems are effective with biofuels, CFB is especially suitable for large boiler load ranges.
ZG boiler engineer said, "Bed combustion temperature control is fundamental to fluid-bed boilers, Bed temperature is controlled to limit emissions and to limit bed material agglomeration."
Agglomeration can be caused by alkaline ash, other metals, and phosphates combining with alumina and silica to form low-melting-point eutectics that coat the bed particles. If alkali concentrations are too high the coatings melt and bond the particles together; these larger agglomerated particles become too heavy and interfere with the fluidization process.
CFB technology provides fuel flexibility in that it can burn wood and high Btu fuels. ZG report that CFBs are common in Europe for renewable energy projects that burn lower moisture fuels, such as clean urban waste wood.
"Making the decision between a BFB or CFB system is not always obvious and should be evaluated on a case-by-case basis," advises by exports from ZG CFB boiler company. "Parasitic power requirements play a very important role in the evaluation process and ultimately system reliability is critical for any given project. That evaluation begins with a thorough