How Does Circulating Fluidized Bed Boilers Work?

October 14, 2020

As industrial boiler industry technology development, the development of a new kind of efficient and low pollution equipment of cfb boiler, it is on the basis of the fluidized bed boiler, using fly ash recirculation combustion, keep the original fluidized bed boiler fuel adaptability is strong, good effect of heat transfer, load, convenient adjustment of the new type boiler in power plant, industrial and other fields has been widely used. I believe that many people are not familiar with this kind of equipment, here for you to introduce in detail the operation principle of energy-saving circulating fluidized bed boilers and working mode.

shx industrial CFB boiler

shx industrial CFB boiler

Composition of Circulating Fluidized Bed Boiler

  1. Boiler body: it mainly includes starting burner, air chamber, air distributing device, furnace, gas-solid separator, material return device, drum, descending pipe, water cooling wall, superheater, economizer, air preheater, etc.
  2. Auxiliary equipment: mainly including blower, induced draft fan, return fan, crusher, coal feeder, slag cooler, dust collector, desulfurization and denitrification equipment, chimney, etc.


Structural Features of CFB Boiler

  1. The most important structural feature of the fluidized bed boiler is the material circulation system, which is composed of air distributing device, combustor, gas-solid separator, feed-back device, ignition device and other devices.
  2. The combustor, separator and recharging device are known as the three core components of the CFB boiler and constitute the particle circulation loop of the CFB boiler, which is distinct from other boilers in structure and a unique system of the CFB boiler.


Operating Principle of Circulating Fluidized Bed Boiler

  1. Fuel after crusher to the appropriate particle size, the coal feeder from upper wind plate into the combustion chamber cloth, mixed with combustion chamber hot boiling material, rapid heating, fuel burning quickly, in under the action of high air velocity, full of furnace, and a large number of solid particles is carrying out the combustion chamber, the bullishness of solid separator after the separation, separation down the material by material loopback device back to continue to participate in the combustion chamber of a stove or furnace.
  2. The high-temperature flue gas derived from the separator will be discharged by the chimney through the dust collector after the heat exchange between the tail flue and the convection heating surface.
circulating fluidized bed boilers

circulating fluidized bed boilers

Environmental Protection Characteristics of CFB Boiler

  1. Boiler thermal efficiency shall not be lower than 88% (bituminous coal);
  2. Low bed pressure, low flow rate design, reasonable ratio of primary and secondary air, so as to reduce the wind pressure on the fan; reduce the electrical power of the motor.
  3. Adjust the heating surface distribution of the boiler to ensure the desulfurization efficiency in the furnace reaches more than 90%; Combined with the measures of desulphurization tower outside the furnace, the original discharge of SO2 is below 35mg/Nm3.
  4. Low nitrogen emission: adopt low bed temperature design of 860-880℃; Low oxygen design is adopted to ensure the final NOx emission concentration of the boiler ≤50mg/Nm3 after the sellout device.


Now the whole world pays great attention to environmental protection, and the environmental protection requirements for the boiler industry are also very high, so the circulating fluidized bed boiler has become the first choice of new combustion technology with high efficiency and low pollution. Wuxi ZOZEN Boiler Co., LTD., as a large boiler manufacturer in China, focuses on the r&d and design of low-emission CFB boilers, and takes the lead in increasing the technical reserve of low-emission boilers and strengthening the layout of domestic and foreign markets through information technology. At present, we have successfully cooperated with customers in more than 100 countries and regions all over the world and obtained high praise.

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