High Efficiency - FBC boilers can burn fuel with a combustion efficiency of over 95% irrespective of ash content. FBC boilers can operate with overall Thermal efficiency of 82% (plus or minus 2%).
Compact in Boiler Size - High heat transfer rate over a small heat transfer area immersed in the bed result in overall size reduction of the boiler.
Fuel Flexibility - FBC boilers can be operated efficiently with a variety of fuels. Even fuels like Coal , Husk , agro waste can be burnt efficiently. These can be fed either independently or in combination with coal into the same furnace.
Ability to Burn Low Grade Fuel - FBC boilers would give the rated output even with inferior quality fuel. The boilers can fire coals with ash content as high as 60% and having calorific value as low as 2,500 kcal/kg. Even carbon content of only 1% by weight can sustain the fluidised bed combustion.
Ability to Burn Fines - Coal containing fines below 6 mm can be burnt efficiently in FBC boiler, which is a very difficult to achieve in conventional firing system.
Low Corrosion and Erosion - The corrosion and erosion effects are less due to lower combustion temperature, softness of ash and low particle velocity (of the order of 1 m/sec).
Easier Ash Removal - No Clinker Formation- Since the temperature of the furnace is in the range of 750 - 900° C in FBC boilers, even coal of low ash fusion temperature can be burnt without clinker formation. Ash removal is easier as the ash flows like liquid from the combustion chamber. Hence less manpower is required for ash handling.
Less Excess Air - Higher CO2 in Flue Gas - The CO2 in the flue gases will be of the order of 14 - 15% at full load. Hence, the FBC boiler can operate at low excess air - only 20 - 25%.
Simple Operation, Quick Start-Up - High turbulence of the bed facilitates quick start up and shut own. Full automation of start up and operation using reliable equipm
Fast Response to Load Fluctuations - Inherent high thermal storage characteristics can easily absorb fluctuation in fuel feed rates. Response to changing load is comparable to that of oil fired boilers.
No Slagging in the Furnace-No Soot Blowing - In FBC boilers, volatilisation of alkali components in ash does not take place and the ash is non sticky. This means that there is no slagging or soot blowing.
Provisions of Automatic Coal and Ash Handling System - Automatic systems for coal and ash handling can be incorporated, making the plant easy to operate comparable to oil or gas fired installation.
High Reliability - The absence of moving parts in the combustion zone results in a high degree of reliability and low maintenance costs.
Reduced Maintenance - Routine overhauls are infrequent and high efficiency is maintained for long periods.
Quick Responses to Changing Demand - A fluidized bed combustor can respond to changing heat demands more easily than stoker fired systems. This makes it very suitable for applications such as thermal fluid heaters, which require rapid responses.
High Efficiency of Power Generation - By operating the fluidized bed Boiler at elevated pressure, it can be used to generate power with a back pressure steam turbine. And the steam from the turbine exhaust can be utilized for process while generating the power.
