Circulating Fluid Bed (Dry Method) Flue Gas Desulfurization (CFB-FGD)

Circulating fluidized bed flue gas desulfurization technology (dry) of LantianQiushi is mainly suitable for flue gas desulfurization of small and medium-sized coal-fired power plant burning low sulfur coal. The technology has applied in many installations, and has the advantages of simple process, low energy consumption, no waste water discharge.
       First of all, the flue gas from the air preheater of boiler by removing most of the dust using pre dust wiper (when the desulfurization ash and fly ash were need to be collected separately, it needs to set the pre dust wiper, otherwise the flue gas goes directly into the absorption tower) goes into the absorption tower from the bottom, and then the flue passes through the suction at the bottom of the tower to accelerate the convergence of the Venturi tube, and enter the circulating fluidized bed. A water spraying device is arranged on the diffusion section of the outlet of the Venturi tube to reduce the temperature and humidity of the flue gas, so as to create a good desulfurization reaction condition. In virtue of airflow, the desulfurizing agent and circulating material on the inside produce intense turbulence and mixing, and make sufficient contact. In the process of rising, the desulfurizing agent and circulating material form constantly floc and return downward, and floc in the fierce turbulence and continue to be promoted the disintegration of the airflow, dozens of times to make the gas solid the sliding speed up the slip velocity of single particle. Collisions between particles by intense turbulence of particles continuously update the surface of the calcium hydroxide particles of the desulfurizer, and continuously recycle of desulfurization ash,therefore, the utilization ratio of calcium hydroxide of desulfurizing agent is greatly improved. The optimum design of the top structure of the absorption towercan enhance the return of floc and further increases the bed density of the particles in the tower, which makes the instantaneous Ca/S ratio of the bed up to 50. The mechanism of gas-solid two-phase flow in circulating fluidized bed can greatly enhance the mass transfer and heat transfer between gas and solid, which provides a basic guarantee for the high desulfurization rate. The flue gas after the desulfurization reaction discharged from the top, goes into the two stage dust collector dust removal (electrostatic precipitator or bag filter), and then goes into the chimney exhaust by fan after reaching the standard.         

Technical Features:

1. High desulfurization efficiency, up to more than 90%

2. Process system is simple, easy to operate, stable and reliable operation.

3. No reheating of flue gas.

4. The system can be used in a wide range, at the same time, it can effectively remove other pollutants such as SO3 and so on.

5. Desulfurization by-products are dry, and easy to deal with, without waste water and secondary pollution.

6. Small footprint, low investment, low maintenance costs.

7. Clean and tidy operating environment.

8. Low power consumption and low operating cost.

Main Process Flow Diagram