How to arrange the loose wind of the upper and lower legs of the feeder in the CFB coal-fired boiler?

CFB (circulating fluidized bed) coal-fired boilers have several advantages over traditional pulverized coal-fired boilers. Some of the main advantages are:

High fuel flexibility: CFB boilers can use a wide variety of fuels, including coal, biomass, and waste fuels, with varying moisture content and size. This makes them ideal for use in areas where fuel availability and quality are uncertain.

High combustion efficiency: CFB boilers can achieve high combustion efficiency, typically above 99%, due to the high turbulence and mixing of the fuel and air in the fluidized bed.

Lower emissions: CFB boilers can significantly reduce emissions of pollutants such as sulfur dioxide (SO2), nitrogen oxides (NOx), and particulate matter (PM). This is achieved through the use of limestone or other sorbents in the bed, which captures and neutralizes these pollutants.

Lower operating costs: CFB boilers have lower operating costs compared to traditional pulverized coal-fired boilers due to their lower fuel consumption, lower maintenance requirements, and longer service life.

High reliability: CFB boilers have a high level of reliability and availability due to their simple design, low maintenance requirements, and ability to handle a wide range of fuels.

Fuel flexibility: In addition to coal, CFB boilers can use a wide range of fuels, including biomass, waste fuels, and low-quality fuels, which can reduce the cost of fuel and improve energy security.

Overall, CFB coal-fired boilers offer a range of advantages over traditional pulverized coal-fired boilers, including greater fuel flexibility, higher combustion efficiency, lower emissions, lower operating costs, and higher reliability.

In a CFB (circulating fluidized bed) coal-fired boiler, the loose wind of the upper and lower legs of the feeder can be arranged in the following manner:

Upper Leg: The upper leg of the feeder should be positioned above the lower leg and should be at an angle of approximately 45 degrees to the horizontal plane. This angle helps to ensure that the coal particles are evenly distributed across the bed and helps to prevent the formation of stagnant zones.

Lower Leg: The lower leg of the feeder should be positioned below the upper leg and should be at an angle of approximately 30-35 degrees to the horizontal plane. This angle helps to ensure that the coal particles are evenly distributed across the bed and helps to prevent the formation of stagnant zones.

Distance between the upper and lower legs: The distance between the upper and lower legs of the feeder should be as small as possible to ensure that the coal particles are evenly distributed across the bed. Ideally, the distance between the upper and lower legs should be less than the diameter of the coal particles.

Orientation of the feeder: The feeder should be oriented in such a way that it is parallel to the axis of the bed. This helps to ensure that the coal particles are evenly distributed across the bed and helps to prevent the formation of stagnant zones.

It is important to note that the arrangement of the loose wind of the upper and lower legs of the feeder may vary depending on the specific design of the CFB boiler and other operational factors. It is recommended to consult the manufacturer's guidelines or an experienced engineer for specific recommendations on the arrangement of the feeder in a CFB coal-fired boiler.