Research Of Power Plant Desulfurization Wastewater Evaporation Process And The Impact On Desulfurization And Dedusting Of Flue Gas

Increased with the strength of the thermal power construction in our country and the improvement of environmental requirements, coal-fired power plant flue gas emissions of sulfur dioxide treatment will also be more deeply, wet desulfurization technology as the leading technology of the flue gas desulfurization will be widely adopted, its proportion has accounted for the desulfurization of installed capacity of 84%,and it’s one of the most dominant limestone- gypsum method, the most mature technology in the world, the most practical performance, the most stable condition of the desulfurization process. In washing wet limestone flue gas desulfurization process, chloride dissolve in flue gas, which increases the concentration of Cl- in desulphurization washing liquid, and the decline in desulfurization rate due to increased concentration of Cl-, and affect the quality of gypsum. Therefore, a certain amount of waste water is vented from the desulfurization technology system, adding fresh absorption to lower the concentration of Cl- in the absorber, this part of the discharge of waste water is the desulfurization wastewater. General power plant of wet flue gas desulfurization wastewater treatment method is to use the chemical methods such as neutralization, flocculation and precipitation. But due to the special properties of wet desulphurization waste water in thermal power plants, weak acid, p H value is lower than 5.7. High suspended solids, but the grain fine, the main ingredient is dust and desulfurization(Ca SO4 and Ca SO3); contain soluble chloride and fluoride, nitrate, etc. And mercury, heavy metals such as lead, nickel, chromium and arsenic, neutralization, flocculation and precipitation of chemical methods, such as waste water after treatment still can’t remove, and chloride ion is in partial acid corrosive characteristics of water environment, lead to can’t enter the system of wastewater reuse after processing, but also cannot meet the discharge standards. Based on the desulfurization wastewater is difficult to deal with, in recent years the development of the industrial application of energy conversion in droplet evaporation is on the map. It sprays atomized waste water into flue between the air pre-heater and electrostatic precipitators, use of flue gas heat to evaporate the waste water, pollutants in wastewater transformed into crystallization or salts such as solid, with fly ash in flue gas by electrostatic precipitator to collect, to remove pollutants, to achieve zero discharge of pollutants.Pollutants in wastewater into crystalline and other solids, after PCD device(The particulate control device), collected with fly ash in order to remove contaminants and realize zero discharge of pollutants. Evaporation is a fascinating desulfurization wastewater treatment method, because in theory, it can dissolve all species(benign,dangerous or toxic) water, produce a stable solid, which can be dealt with in a landfill, Thus can achieve zero emission of desulphurization wastewater.