Efficient wet type electrostatic-precipitation desulfurization process

Abstract

The invention discloses an efficient wet type electrostatic-precipitation desulfurization system and a process thereof. A wet electrostatic precipitator is used for replacing an existing demister in a desulfurization tower. The wet electrostatic precipitator has more powerful capability and higher efficiency in removal of liquid drops and fine dust in flue gas than the demister, so that the wet electrostatic precipitator achieves high environmental protection discharge requirements, guarantees the desulfurization efficiency, and improves the efficiency of a dust removal system of a desulfurization tower, reduces the discharge concentration of dust at an outlet of the desulfurization tower and achieves the latest discharge standard required by the nation. By means of replacing the demister with the wet electrostatic precipitator, the gypsum rain problem is solved, and joint removal of various pollutants is achieved. Further, a water collection disc is added between a desulfurization absorption area and the wet electrostatic precipitator; as the water collection disc collects flushing water of the wet electrostatic precipitator for recycling, the flushing water of the wet electrostatic precipitator is prevented from entering a neutralization oxidation pond of the desulfurization tower directly, and water balance of the whole system is guaranteed.

Description

technical field [0001] The invention relates to a flue gas dust removal and desulfurization technology of a wet desulfurization system, in particular to a high-efficiency wet electric dust removal and desulfurization technology. Background technique [0002] The dust emission limit of the latest air pollutant emission standard for thermal power plants (GB 13223-2011) has changed from the original 50mg / m 3 Change to 30mg / m 3 , requiring the national implementation of less than 30mg / m in 2012 3 The control standard of the Yangtze River and Pearl River Delta and the Beijing-Tianjin-Hebei region will be controlled at 20mg / m 3 Below, and increase the control indicators of mercury and PM2.5 fine particles. [0003] At present, the dust removal technologies of desulfurization devices mainly include: dry electrostatic precipitator, wet electrostatic precipitator and bag filter. [0004] Wet electrostatic precipitator: Wet electrostatic precipitator can remove particles, liquid d...

AI Technical Summary

Problems solved by technology

However, the disadvantages of the wet electrostatic precipitator are: uniform plate water flow, high resistance, nozzle wear, blockage, equipment corrosion, scaling, and high input costs and difficult sewage treatment. For high dust concentration or high NOx Flue gas conditions with high concentrations are not suitable for use. At present, there is no practical application in the domestic power industry

However, the disadvantage of the dry electrostatic precipitator is that it is particularly sensitive to the specific resistance of dust, and the most suitable specific resistance is 106-1011Ω·cm. When the specific resistance is too high or too low, the dust removal efficiency will drop significantly, especially if the specific resistance is high When a very fine and light powder such as aluminum exists in large quantities, such as SiO 2 Add Al 2 o 3 When the content of Al exceeds 85%, because it is an insulator with a particularly high specific resistance, and it is fine dust Al 2 o 3 There are also viscous and easy-to-stick electrodes, so the reduction in dust removal efficiency is more obvious

In implementing the new standard (30mg / m 3 ), even if the dry electrostatic precipitator is set with 5 or 6 electric fields, it is difficult to meet the latest emission standards, and increasing the electric field will increase the subsequent desulfurization cost

[0006] Bag dust collector: Bag dust collector has advantages in meeting environmental protection requirements in general, especially the ability to collect fine dust and heavy metals, which meets the emission requirements for future environmental protection development, but bag dust collectors have higher requirements for filter bags. At present, Bag dust collectors generally have outstanding problems such as wear, severe corrosion, short life, and high maintenance costs. So far, there are few application performances in China, and there are many problems.

[0007] To sum up, the current desulfurization devices have poor dust removal and mist removal effects, and cannot meet environmental protection emission requirements.

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