Semi-dry desulfurization device and method

Abstract

The invention provides a semi-dry desulfurization device. The semi-dry desulfurization device comprises a U-shaped desulfurization device shell; the U-shaped desulfurization device shell is sequentially provided with a paste semi-dry first-stage desulfurization section, a horizontal flue gas rectifying section, an adding second-stage desulfurization section, a Venturi acceleration section, a Venturi outlet section and a desulfurization bed third-stage desulfurization section in the flowing direction of flue gas; a flue gas inlet and a spraying device are arranged at the top of the paste semi-dry first-stage desulfurization section; the horizontal flue gas rectifying section is provided with a flue gas rectifying device; the adding second-stage desulfurization section is provided with an adding inlet; the Venturi outlet section is provided with a water spraying device; and the desulfurization bed third-stage desulfurization section is provided with a desulfurization flue gas outlet. Thesemi-dry desulfurization device is adopted for semi-dry desulfurization, an ion-type reaction environment, a high-alkali-to-sulfur-rate reaction environment and a high sliding speed are simultaneously achieved for mass transfer and heat transfer, control can be conducted separately according to the temperature of the flue gas at the inlet and the change of the sulfur capacity, the desulfurizationefficiency is improved, the consumption of a desulfurization agent is decreased, and long-term stable operation is achieved.

Description

Technical field [0001] The invention relates to the technical field of flue gas desulfurization, and more specifically, to a semi-dry desulfurization device and method. Background technique [0002] The semi-dry desulfurization process has the ability to synergistically remove multi-component pollutants, does not produce waste water, does not require anti-corrosion in the system, and the chimney is bright and sensory. It is gradually being used on a large scale. The mainstream technologies of the existing semi-dry desulfurization tower include: using dry slaked lime powder as a desulfurizing agent, and using slaked lime slurry as a desulfurizing agent; among them, the semi-dry desulfurization tower that uses dry slaked lime powder as a desulfurizing agent mainly includes a CFB desulfurization tower. This kind of desulfurization tower uses water spraying to cool and humidify to create a similar ionic reaction environment, and use the huge sliding speed in the tower for mass and he...

AI Technical Summary

Problems solved by technology

The current mainstream technologies for semi-dry desulfurization towers include: using dry slaked lime powder as a desulfurizer, and using slaked lime slurry as a desulfurizer; among them, the semi-dry desulfurization towers that use dry slaked lime powder as a desulfurizer mainly include CFB desulfurization towers. This kind of desulfurization tower uses water spraying to cool down and increase humidity to create an ion-like reaction environment, and uses the huge sliding speed in the tower to conduct mass transfer and heat transfer, thereby completing desulfurization; but because the water injected cannot remove slaked lime and SO in the flue gas 2 Completely ionized, unable to form a completely ionized reaction environment, the consumption of desulfurizer is large, especially the inlet SO 2 When the concentration is high, the desulfurization agent consumption is greater and the desulfurization efficiency is low; while the semi-dry desulfurization towers using slaked lime slurry as desulfurization agent mainly include SDA desulfurization tower and NID desulfurization tower; among them, the SDA desulfurization tower uses hydrated lime slurry directly sprayed into the tower SO in internal and flue gas 2 Contact, direct ionic reaction, adjust the amount of desulfurizer slurry sprayed according to the temperature of the inlet flue gas and the change of sulfur capacity; The desulfurization efficiency cannot meet the requirements due to the agglomeration of the absorption tower or insufficient addition of desulfurizer. In addition, due to the low alkali-sulfur ratio in the tower, the material in the tower falls at a low speed, and there is no large amount of material as an evaporation carrier, only a small amount can be sprayed. Water and slaked lime (slurry) cannot form a stable reaction environment with high alkali-sulfur ratio, the desulfurization efficiency is low, the consumption of desulfurizer is high, the absorption tower is easy to agglomerate, and it is difficult to meet the increasingly stringent environmental protection requirements; and the NID desulfurization tower uses hydrated lime and The desulfurization ash is mixed into a slurry and sprayed into the absorption tower; however, similar to SDA, there are problems that the inlet flue gas temperature cannot be matched, and the sulfur capacity cannot be adjusted when the change of sulfur capacity is inconsistent. The reaction temperature cannot be lowered, the desulfurization efficiency is low, the desulfurization agent consumption is high, and the absorption tower is easy to agglomerate, etc.

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