Dual-alkali flue gas desulfurization and dust removal system

Abstract

The invention discloses a dual-alkali flue gas desulfurization and dust removal system in the technical field of flue gas desulfurization, which comprises a desulfurization tower, an induced draft fan, an exhaust chimney, a regeneration tank, a sedimentation tank and a circulating tank, a flocculation tank and an adjusting tank are connected between the desulfurization tower and the regeneration tank, the desulfurization tower, the flocculation tank, the adjusting tank and the regeneration tank are sequentially communicated, the bottom of the flocculation tank is communicated with a slurry discharge pump, the adjusting tank is communicated with the regeneration tank through a water decanter, the flocculation tank is provided with a flocculant feeder, a flocculant is composite polysilicate aluminum, the sedimentation tank is communicated with an oxidation tank, the oxidation tank is communicated with a lime rotational flow station, the gypsum rotational flow station is connected with a vacuum belt dehydrator, an online pH value monitor is fixedly mounted in the circulating tank, and stirrers are fixedly mounted in the regeneration tank, the circulating tank and the flocculation tank. The flocculation tank is additionally arranged, heavy metal ions are reduced and removed, the pH value is adjusted on line, the desulfurization efficiency is improved, and gypsum can be re-utilized.

Description

technical field [0001] The invention relates to the technical field of flue gas desulfurization, in particular to a dual-alkali process flue gas desulfurization and dust removal system. Background technique [0002] SO2 emitted by humans is the first major pollutant in the atmospheric environment, and it is one of the main pollutants that cause acid rain. At present, the more mature flue gas desulfurization technologies at home and abroad are mostly wet desulfurization processes, such as limestone / gypsum method, dual-alkali method, sodium-alkali method, ammonia method, magnesium method, etc. Among them, the limestone / gypsum method is most widely used due to the low cost of desulfurization raw materials, but this method has problems such as large investment, high operating cost, equipment corrosion, scaling, and clogging. Other desulfurization methods have the problems of high cost of desulfurization raw materials (such as sodium carbonate or sodium hydroxide, ammonia water,...

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Problems solved by technology

[0013] In the existing double-alkali flue gas desulfurization process, the reuse of resources is low; the heavy metal ions in the circulating water have a certain catalytic effect on the sulfite, and a certain amount of waste water needs to be discharged during the cycle, and supplementary water is added to clean the demister At the same time, the concentration of heavy metal ions is desalinated, and the pH value of the circulating water is unstable, and the desulfurization effect is reduced during recycling. Moreover, most of the current double-alkali desulfurization devices have incomplete oxidation and crystallization of desulfurization products, which makes it difficult to dehydrate, and there are too many impurities. Comprehensive utilization

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