Circulating Fluidised Bed Combustion Boiler (CFBC)

Capacities: Up to 500 TPH
Design pressure & temperature: Upto 150 kg/cm2 (g) & 545ºC
Fuels: Handle high sulphur, high ash and high moisture fuels, pet-coke, sludge, washery rejects, lignite, biomass

 

Solids Separator (Hot Cyclone – Plate Type)

Plate type un-cooled (hot) cyclones with Loop Seal assembly are adopted in Enmas GB CFBC boilers. Hot cyclones separate the circulating bed material from the flue gas stream leaving the furnace at around 880DegC.

  • The solid particles separated from the flue gas are re-circulated back into the furnace through the loop seal.
  • A vortex finder is provided to enhance the separation efficiency of the hot cyclone.
  • The flue gas containing the fine ash particles exits the cyclones through the vortex finder and outlet flue.
  • The entire hot cyclone, loop seal and outlet flue assembly is provided with a multi layer refractory lining.
  • The design and arrangement of the hot cyclone is based on specific sizing criteria that are a function of the actual gas velocities entering and leaving the cyclone.
  • Fast to respond to load changes. Response time is 4% to 5% per minute which may be better than other types of combustors.

Fuel Flexibility

  • The range of fuels that can be successfully burned in Enmas GB CFBs is very broad.
  • The CFB, with its low combustion temperature is an especially good solution for coals with low ash fusion temperatures,
  • Preventing the formation of slag.
  • High Combustion Efficiency
  • The continuous circulation of solids through the EnmasGB CFB system keeps the fuel in an ideal combustion environment for a long period of time.
  • The long residence time results in very efficient fuel combustion, while minimising process changes resulting from sudden changes in fuel quality or mixes.

Low SO2 Emissions

  • EnmasGB CFBs do not require complicated and expensive downstream flue gas desulphurisation equipment to meet environmental regulations.
  • Better sulphur capture with less limestone and improved heat transfer.
  • The ratio between operating gas velocity and minimum solids entrainment velocity allow turndown ratios as high.
  • Operation over a wide range of boiler loads is possible without starting and stopping burners and auxiliary equipment.

Low Nox Emissions

  • Emissions of nitrous oxides (NOx) are very low with a EnmasGB CFB boiler.
  • This is due to the combination of low combustion temperature and staged combustion.

Elimination of Slagging

  • The low combustion temperature of 880 – 900 DegC in EnmasGB CFB technology eliminates slag formation in the furnace and reduces the volatilisation of alkali salts.
  • Operating at such low temperatures also means boiler corrosion and convective surface fouling is reduced.

Furnace Erosion Potential

  • The maximum velocity of flue gas across various zones is fixed at an optimum level.
  • Considering low temperature staged combustion associated with the CFBC, the ash particle shape and structure do not reach the level of creating adverse implications in this velocity range.
  • Elimination of hundreds of opening for the arrangement of heating surfaces and in turn the access and inspection openings
  • No horizontal elements need to be arranged in the furnace across the gas flow carrying higher solid density.

Redundancy

In the absence of rotating type of equipments, complicated fuel pipes etc. the redundancy factor is not applicable for CFB.

High reliability

  • CFB boilers have demonstrated a high availability due to the simple proven design as offered now. As a result, we are sure to provide excellent performance results and high reliability.
  • CFB unit, with less number of rotary equipments combined with a variety of design features that minimize the maintenance efforts and resultant costs, the staff deployment / man power requirement will accordingly be less compared with other types of units.

Environmental Aspect

  • We have the ability to provide equipments that consistently meet strict environmental requirements. EGBPSPL’s CFB offered complies with guaranteed emission requirements.

Easy to operate/Maintain

  • CFB boiler requires less manpower to operate and maintain.
  • This is proved based on the number of operators required for a CFB plant.
  • The reliability is excellent which is why many industrial customers select CFB, for their power plants.
  • The parameters to be monitored in CFB are less.
 
 

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