Dry flue gas desulfurization refers to the application of powder or granular absorbent, adsorbent or catalyst to remove SO2 in flue gas. Definition of dry flue gas desulfurization: the CaCO3 injected into the furnace is calcined and decomposed into CaO at high temperature, which reacts with SO2 in the flue gas to generate calcium sulfate. Electron beam irradiation or activated carbon adsorption is used to convert SO2 into ammonia sulfate or sulfuric acid, which is collectively referred to as dry flue gas desulfurization technology.

Its advantages are simple process, no sewage, sewage acid treatment problems, low energy consumption, especially after the purification of flue gas temperature is higher, conducive to the chimney exhaust diffusion, will not produce "white smoke" phenomenon, after purification of flue gas does not need secondary heating, small corrosion; Its disadvantage is low desulfurization efficiency, huge equipment, large investment, large area, high technical requirements.

Technical characteristics

1) adopt the integrated design of digestion of quick lime (CaO) and humidification of ash cycle to ensure the fresh digestion of high-quality hydrated lime (Ca(OH)2) immediately put into the cycle desulfurization reaction;

2) water film is formed on the surface of dust particles by using circulating ash to carry water. A thin film of water on the surface of dust particles evaporates in the smoke stream in an instant, forming an ideal reaction environment suitable for temperature and humidity in a very short time. At the same time, it overcomes the wall sticking problem in the traditional semi-dry desulfurization reactor.

3) the total reaction time is greatly reduced due to the reduction of the time needed to establish the ideal reaction environment, which can effectively reduce the height of the desulfurization reactor;

4) the flue gas flows in the reactor at high speed. The whole device is compact in structure, small in volume and reliable in operation. Good load adaptability of the device;

5) the desulfurization by-products are in dry state, and there is no water generated in the system. The end product has good fluidity and is suitable for pneumatic conveying. The flue gas can be discharged directly without reheating after desulfurization.

6) absorbent requirements are not high, can be widely obtained.

7) the initial investment and operation cost are greatly reduced by reducing the size of the absorber, reducing the floor area and avoiding the complex and expensive digestion preparation system;

8) high desulfurization efficiency, desulfurization efficiency can reach more than 90%.