Device and process for coordinative treatment of smoke desulfuration and dedusting

Abstract

The invention discloses a device and a process for coordinative treatment of smoke desulfuration and dedusting. The process includes that crude smoke enters an absorption tower and sequentially pass through a tray layer, a spray layer, a sedimentation and cooling area and an efficient demisting layer and out of the outlet of the absorption tower, the smoke entering the absorption tower in the tray layer is reshaped and rises up at uniform speed over the section of the absorption tower, SO2 in the smoke and size in the accumulative liquid layer and the sprayer layer above the tray can be effectively removed, saturated smoke with small size drops and dust can be settled through the cooling area after desulfurized, and size drops and dust may be abundantly settled. The size drops and dust unsettled can enter a cyclone demister layer along with airflow and be removed through cyclone and collision, and clean smoke treated can be discharged from the outlet of the absorption tower. By the process of reshaping the smoke and sequentially spraying, absorbing and efficiently removing dust and mist, desulfurization, and demisting and dedusting efficiency of the wet-method desulfurization device is improved, and operation energy consumption is lowered.

Description

technical field [0001] The invention relates to the field of resource and environmental protection, in particular to a collaborative treatment process for returning flue gas desulfurization and dust removal. Background technique [0002] At present, the flue gas desulfurization system of thermal power plants at home and abroad mostly adopts the wet limestone-gypsum desulfurization process. The limestone-gypsum desulfurization process has the advantages of high desulfurization efficiency, stable system operation, wide application range, easy access to raw materials and low operating costs, and has been widely used. [0003] However, with the continuous improvement of environmental protection requirements, SO 2 The requirements for emission indicators are becoming more and more stringent. The "Emission Standard of Air Pollutants for Coal-fired Units in Thermal Power Plants" (GB13223-2011) requires sulfur dioxide ≤ 50mg / Nm 3 , Nitrogen oxide≤100mg / Nm 3 , Dust≤20mg / Nm 3 . A...

AI Technical Summary

Problems solved by technology

After 2014, the Chinese government requires that the flue gas emission concentration of thermal power units gradually implement the emission standards of natural gas units in the new standard, that is, sulfur dioxide is required to be ≤35mg / Nm 3 , Nitrogen oxide≤50mg / Nm 3 , Dust≤5mg / Nm 3 , the existing desulfurization and dust removal technology basically cannot realize

[0006] (1) The flue gas flow field in the tower is uneven: the flue gas flow rate in the flue of the existing wet desulfurization technology is 10-15m / s, and the flue gas flow rate in the tower is 2.5-4m / s. The vertical flow quickly changes to the vertical flow, and the flue gas flow rate is very uneven on the horizontal section of the tower

When the uneven air flow passes through the spray layer, the low-speed gas has a long gas-liquid contact time and has good desulfurization efficiency. Most high-speed gases have low desulfurization efficiency due to the short gas-liquid contact time, resulting in low average desulfurization efficiency.

In order to improve the average desulfurization efficiency of flue gas, it is often necessary to increase the liquid-gas ratio and increase the circulation volume of slurry, and the energy consumption of the desulfurization device is high

[0007] (2) The demisting effect of the demister is not ideal: the existing wet desulfurization devices mostly use folding plate type flat demisters or roof demisters, and the height from the spray layer is between 1.5-2m, and the treated flue gas is entrained The amount of slurry is large, and it is easy to block the demister in the air flow with uneven flow field, and the gap of the folded plate demister is large, and the demisting effect on small droplets and dust is poor

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